Abstrict
Electric heaters and blower units are disposed inside an occupant
seat having exterior cover members, each of which has a plurality
of outlet openings. Each electric heater heats the corresponding
exterior cover member, and each blower unit blows air through the
outlet openings of the corresponding cover member. Manipulation
dials are provided to manipulate the corresponding electric heaters
and blower units. A variable heating power command signal, which
commands increasing or decreasing of a heating power of each corresponding
electric heater, and a variable flow rate command signal, which
commands increasing or decreasing of an air flow rate of each corresponding
blower unit, are generated through adjustment manipulation of the
manipulation dial in synchronism with movement of the manipulation
dial.
Claims
What is claimed is:
1. A seat air conditioning system for a vehicle occupant seat that
is placed in a passenger room of a vehicle and includes at least
one exterior cover member, which forms an occupant contacting surface
of the seat for contacting with a vehicle occupant and has a plurality
of outlet openings penetrating through the exterior cover member,
the seat air conditioning system comprising: at least one electric
heater disposed inside the seat, wherein each electric heater heats
a corresponding one of the at least one exterior cover member of
the seat; at least one blower unit disposed inside the seat, wherein
each blower unit blows air through the outlet openings of a corresponding
one of the at least one exterior cover member; a single manipulating
means for manipulating the at least one electric heater and the
at least one blower unit; an air flow rate command signal generating
means for outputting the air flow rate command signal; and a heating
power command signal generating means for outputting the heating
power command signal, wherein: the single manipulating means is
disposed inside the passenger room and is manually manipulatable;
a variable heating power command signal, which commands increasing
or decreasing of a heating power of each corresponding electric
heater, and a variable flow rate command signal, which commands
increasing or decreasing of an air flow rate of each corresponding
blower unit, are generated through adjustment manipulation of the
single manipulating means in synchronism with movement of the single
manipulating means; the air flow rate command signal generating
means and the heating power command signal generating means are
arranged adjacent to each other within a movable range of the manipulating
means and are placed in two different imaginary planes, respectively;
and the air flow rate command signal of the air flow rate command
signal generating means and the heating power command signal of
the heating power command signal generating means are varied in
synchronism with positional change of the manipulating means within
the movable range of the manipulating means.
2. A seat air conditioning system according to claim 1, wherein
the manipulating means is a dial, which is manually rotatable.
3. A seat air conditioning system according to claim 1, wherein
the movable range of the manipulating means includes: an OFF position,
in which the electric heater and blower unit are both turned off;
an air flow manipulation range that is located on one side of the
OFF position in the movable range of the manipulating means, wherein
when the manipulating means is moved within the air flow manipulation
range from the OFF position toward a first end of the movable range
of the manipulating means, an air flow rate of the blower unit is
increased; and a heater manipulation range that is located on the
other side of the OFF position in the movable range of the manipulating
means, wherein when the manipulating means is moved within the heater
manipulation range from the OFF position toward a second end of
the movable range of the manipulating means opposite to the first
end, a heating power of the electric heater is increased, and at
the same time an air flow rate of the blower unit is slightly increased
by a relatively small amount.
4. A seat air conditioning system according to claim 1, wherein:
the air flow rate command signal generating means is a variable
resistor that has a variable resistance value, which varies according
to an operational position of the manipulating means in the movable
range of the manipulating means; and the heating power command signal
generating means is a variable resistor that has a variable resistance
value, which varies according to an operational position of the
manipulating means in the movable range of the manipulating means.
5. A seat air conditioning system according to claim 1, further
comprising a control means for controlling the electric heater and
the blower unit, wherein: when the air temperature in the passenger
room is equal to or less than a predetermined temperature upon energization
of the electric heater, the control means turns off the blower unit;
and when the air temperature in the passenger room is greater than
the predetermined temperature upon energization of the electric
heater, the control means turns on the blower unit.
6. A seat air conditioning system according to claim 1, further
comprising a control means for controlling the electric heater and
the blower unit, wherein: the control means keeps the blower unit
turned off until a predetermined time period elapses since energization
of the electric heater; and the control means turns on the blower
unit upon the elapse of the predetermined time period.
7. A seat air conditioning system according to claim 5, further
comprising an operational mode for controlling an air flow rate
of the blower unit upon activation of the blower unit based on an
informational value, which indicates a corresponding heating heat
load of the entire vehicle.
8. A seat air conditioning system according to claim 1, further
comprising a control means for controlling the electric heater and
the blower unit, wherein: the control means turns off the blower
unit upon energization of the electric heater when at least one
of the following two conditions are satisfied: the air temperature
in the passenger room is equal to or less than a predetermined temperature;
and an informational value, which indicates a corresponding heating
heat load of the entire vehicle, is equal to or less than a predetermined
value; and the control means turns on the blower unit upon energization
of the electric heater when the following two conditions are both
satisfied: the air temperature in the passenger room is greater
than the predetermined temperature; and the informational value,
which indicates the corresponding heating heat load of the entire
vehicle, is greater than the predetermined value.
9. A seat air conditioning system according to claim 8, further
comprising an operational mode for controlling an air flow rate
of the blower unit upon activation of the blower unit based on the
informational value, which indicates the corresponding heating heat
load of the entire vehicle.
10. A seat air conditioning system according to claim 5, wherein
the control means is a control device that automatically controls
a passenger room air conditioning unit, which performs air conditioning
of the passenger room.
11. A seat air conditioning system according to claim 7, wherein
the informational value, which indicates the corresponding heating
heat load of the entire vehicle, is a target outlet air temperature
of a passenger room air conditioning unit, which performs air conditioning
of the passenger room.
12. A seat air conditioning system according to claim 1, wherein:
the at least one exterior cover member includes two exterior cover
members; the seat includes: a seat cushion assembly that includes
one of the two exterior cover members and supports buttocks of the
vehicle occupant; and a backrest assembly that includes the other
one of the exterior cover members and supports a back region of
the vehicle occupant; the at least one electric heater includes
two electric heaters, which are arranged in the seat cushion assembly
and the backrest assembly, respectively; and the at least one blower
unit includes two blower units, which are arranged in the seat cushion
assembly and the backrest assembly respectively.
Description CROSS REFERENCE TO RELATED APPLICATION
This application is based on and incorporates herein by reference
Japanese Patent Application No. 2002-34163 filed on Feb. 12, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle seat air conditioning
system installed in a vehicle occupant seat.
2. Description of Related Art
Various vehicle seat air conditioning systems have been proposed.
One such a vehicle seat air conditioning system has an electric
heater and a blower unit installed in a vehicle occupant seat. In
this vehicle seat air conditioning system, an exterior cover member
of the seat can be directly heated by the electric heater, and air
(warm air), which is heated by the electric heater, can be blown
outwardly through outlet openings of the exterior cover member of
the seat.
In the previously proposed seat air conditioning system, a heater
manipulating member for adjusting a heating power of the electric
heater installed in the seat is provided separately from a blower
manipulating member for adjusting an air flow rate of the blower
unit installed in the seat, so that the operation of the seat air
conditioning system is not simple.
Furthermore, in the vehicle, due to limitation imposed by a balance
between the amount of charged electricity, which is charged in a
vehicle battery by a vehicle electric generator, and the amount
of discharged electricity, which is discharged from the vehicle
battery, the heating power of the electric heater installed in the
seat is normally set to a relatively small value, i.e., about 60
to 90 W. Thus, when an excessively high air flow rate, which is
excessive with respect to the heating power of the electric heater,
is set, the cold air, which has not been sufficiently heated, is
blown to a vehicle occupant seated on the seat. As a result, the
occupant experiences cold sensation, deteriorating feeling of warmness
of the vehicle occupant.
SUMMARY OF THE INVENTION
The present invention addresses the above disadvantages. Thus,
it is an objective of the present invention to improve manipulability
of a vehicle seat air conditioning system, which includes an electric
heater and a blower unit installed therein.
It is another objective of the present invention to prevent deterioration
of feeling of warmness induced by blowing cold air from a seat that
has the seat air conditioning system.
To achieve the objectives of the present invention, there is provided
a seat air conditioning system for a vehicle occupant seat that
is placed in a passenger room of a vehicle and includes at least
one exterior cover member, which forms an occupant contacting surface
of the seat for contacting with a vehicle occupant and has a plurality
of outlet openings penetrating through the exterior cover member.
The seat air conditioning system includes at least one electric
heater and at least one blower unit, which are disposed inside the
seat. Each electric heater heats a corresponding one of the at least
one exterior cover member of the seat, and each blower unit blows
air through the outlet openings of a corresponding one of the at
least one exterior cover member. The seat air conditioning system
further includes a single manipulating means for manipulating the
at least one electric heater and the at least one blower unit. The
single manipulating means is disposed inside the passenger room
and is manually manipulatable. A variable heating power command
signal, which commands increasing or decreasing of a heating power
of each corresponding electric heater, and a variable flow rate
command signal, which commands increasing or decreasing of an air
flow rate of each corresponding blower unit, are generated through
adjustment manipulation of the single manipulating means in synchronism
with movement of the single manipulating means.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with additional objectives, features and
advantages thereof, will be best understood from the following description,
the appended claims and the accompanying drawings in which:
FIG. 1 is a partially fragmented schematic perspective view showing
a vehicle seat air conditioning system according to a first embodiment
of the present invention;
FIG. 2 is a schematic circuit diagram showing electrical control
arrangement according to the first embodiment;
FIG. 3 is a schematic view showing an arrangement of a seat air
conditioning panel according to the first embodiment;
FIG. 4 is a flow chart showing operation according to the first
embodiment;
FIG. 5 is a diagram showing operational characteristics according
to the first embodiment;
FIG. 6 is a flow chart showing operation according to a second
embodiment of the present invention; and
FIG. 7 is a flow chart showing operation according o a third embodiment
of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Various embodiments of the present invention will be described
with reference to the accompanying drawings.
(First Embodiment)
FIG. 1 is a schematic view of a vehicle occupant seat 10 according
to a first embodiment of the present invention. Specifically, the
seat 10 shown in FIG. 1 is used as a driver seat or a front non-driver
seat of a vehicle.
The seat 10 includes a seat cushion assembly 11 and a backrest
assembly 12. The seat cushion assembly 11 supports buttocks of a
vehicle occupant. The backrest assembly 12 supports a back region
of the occupant. A first blower unit 13 is arranged inside the seat
cushion assembly 11, and a second blower unit 14 is arranged inside
the backrest assembly 12. Each of the first and second blower units
13, 14 includes an electric motor and a blower fan driven by the
electric motor.
An air intake opening (not shown) of the first blower unit 13 is
arranged at a lower side of the seat cushion assembly 11. The air
in a passenger room of the vehicle is drawn by the first blower
unit 13 through the air intake opening and is then blown by the
first blower unit 13 against an exterior cover member 16 of the
seat cushion assembly 11 through an air passage 15 arranged in the
seat cushion assembly 11, so that the air is discharged toward the
body of the occupant through a plurality of air outlet openings
17, which extend through the exterior cover member 16, as indicated
by arrows "a" in FIG. 1.
The second blower unit 14 blows the air in a manner similar to
that of the first blower unit 13. That is, an air intake opening
(not shown) of the second blower unit 14 is arranged in a rear surface
of a lower end section of the backrest assembly 12. The air in the
passenger room of the vehicle is drawn by the second blower unit
14 through the air intake opening and is then blown to the body
of the occupant through an internal air passage 18 of the backrest
assembly 12 and then through a plurality of air outlet openings
20 arranged in an exterior cover 19 of the backrest assembly 12,
as indicated by arrows "b" in FIG. 1.
A passenger room air conditioning unit 21 is arranged inside an
instrument panel (not shown) that is arranged in a front section
of the passenger room. As is known in the art, the passenger room
air conditioning unit 21 includes an inside air/outside air switching
box, a centrifugal blower, a cooling heat exchanger, a heating heat
exchanger, a temperature adjusting mechanism and a blow mode switching
mechanism. The centrifugal blower blows the inside air or the outside
air, which is introduced into the inside air/outside air switching
box. The cooling heat exchanger and the heating heat exchanger exchange
heat with the air blown by the centrifugal blower. The temperature
adjusting mechanism adjusts the temperature of the blown air, which
is discharged from the passenger room air conditioning unit 21 into
the passenger room. The blow mode switching mechanism switches the
blow mode of the blown air discharged from the passenger room air
conditioning unit 21 into the passenger room. With the above arrangement,
the blown air, which is blown by the centrifugal blower, is cooled,
dehumidified and/or reheated in the passenger room air conditioning
unit 21 and is then discharged into the passenger room after the
temperature adjustment. Thus, each of the first blower unit 13 and
the second blower unit 14 can suction the conditioned air in the
passenger room and can discharge it.
Particularly, in a case where a rear seat heater duct 21a is arranged
beneath the front seat 10, a rear seat heater discharge opening
21b of the rear seat heater duct 21a is normally positioned slightly
rearward of the fore-and-aft center of the front seat 10. The conditioned
air (warm air) of the passenger room air conditioning unit 21 is
discharged from the rear seat heater duct 21a toward the feet of
the rear passengers through the rear seat heater discharge opening
21b arranged at a distal end of the rear seat heater duct 21a. The
air intake opening of the first blower unit 13 of the seat cushion
assembly 11 is designed to open near the rear seat heater discharge
opening 21b. Thus, during the heating operation in the winter season,
the warm air, which is discharged from the rear seat heater discharge
opening 21b, can be drawn and blown by the first blower unit 13.
Furthermore, in each of the seat cushion assembly 11 and the backrest
assembly 12, an electric heater 22, 23 is arranged on the backside
of the exterior cover member 16, 19. Each electric heater 22, 23
includes a wire-type electric resistor and is arranged along a meandering
path in a wide area of an occupant contacting surface of each corresponding
one of the seat cushion assembly 11 and the backrest assembly 12.
Thus, when each electric heater 22, 23 is energized to generate
heat, the exterior cover member 16, 19, which serves as the occupant
contacting surface of the seat cushion assembly 11 or of the backrest
assembly 12, can be directly heated by the electric heater 22, 23.
Furthermore, when each blower unit 13, 14 is operated simultaneously
with the energization of the electric heater 22, 23, the warm air
heated by the electric heater 22, 23 can be discharged through the
outlet openings 17, 20.
The exterior covering member 16, 19 of the seat 10 is chosen to
be made of leather or fabric upon consideration of a seat design.
In the case of the exterior covering member 16, 19 made of the leather,
a relatively large number of small holes, each of which has an inner
diameter of about 0.8 to 1.0 mm, are made through the exterior covering
member 16, 19 to form the outlet openings 17, 20 since the leather
does not substantially permeate the air. Contrary to this, the exterior
covering member 16, 19 made of the fabric originally has spaces
between the fibers of the fabric to allow permeation of the air,
so that there is no need to perforate the exterior covering member
16, 19. That is, in the case of the exterior covering member 16,
19 made of the fabric, the spaces between the fibers of the fabric
can serve as the outlet openings 17, 20.
FIG. 2 schematically shows an electrical arrangement according
to the first embodiment. The air conditioning control device 30
is provided as a control means for controlling the temperature and
a flow rate of the air discharged from the passenger room air conditioning
unit 21 into the passenger room. Furthermore, in the first embodiment,
the air conditioning control device 30 also controls an air flow
rate of each of the blower units 13, 14 of the seat air conditioning
system.
The air conditioning control device 30 includes a known microcomputer
and a peripheral circuit. The known microcomputer includes, for
example, a central processing unit (CPU), a read only memory (ROM)
and a random access memory (RAM). The ROM stores a control program
for performing air conditioning control, and the air conditioning
control device 30 performs computations and other operations based
on the control program. Sensor output signals from a group of sensors
31, operation signals from an air conditioning control panel 32
and operation signals from a seat air conditioning control panel
33 are inputted to input terminals of the air conditioning control
device 30. Electric power is supplied from a vehicle battery 34
to the air conditioning control device 30 through an ignition switch
35 of a vehicle engine.
The group of sensors 31 includes a sensor for measuring the outside
air temperature (i.e., the air temperature outside the passenger
room) TAM, a sensor for measuring the inside air temperature (i.e.,
the air temperature inside the passenger room) TR, a sensor for
measuring the amount of solar radiation TS, a sensor for measuring
the water temperature TW and a sensor for measuring the evaporator
outlet air temperature (evaporator cooling temperature) TE.
The air conditioning control panel 32 is arranged adjacent to the
instrument panel (not shown) in front of the driver seat in the
passenger room and includes operation switches 32a-32e, which are
operated by the occupant. Among the operation switches 32a-32e,
a target air temperature setting switch 32a outputs a signal, which
indicates a target air temperature of the passenger room, and an
inside air/outside air selecting switch 32b outputs a signal for
manually setting one of an inside air mode and an outside air mode
as an air intake mode.
A blow mode selecting switch 32c outputs a signal for manually
setting one of a face mode, a bi-level mode, a foot mode, a foot
defroster mode and a defroster mode as a blow mode. An air flow
rate selecting switch 32d outputs a signal for manually setting
on/off of the blower of the passenger room air conditioning unit
21. The air flow rate selecting switch 32d also outputs a signal
for manually setting an air flow rate of the blower of the passenger
room air conditioning unit 21. An air conditioning switch 32e outputs
the on signal and the off signal to intermittently operate the air
conditioning compressor.
Drive motors 13a, 14a of the blower units 13, 14 of the seat air
conditioning system are connected to output terminals of the air
conditioning control device 30 through corresponding motor drive
circuits 13b, 14b. Furthermore, for achieving air conditioning operation
of the passenger room air conditioning unit 21, an electromagnetic
clutch 36 of the compressor, a blower motor 37, an inside air/outside
air switching door actuator motor 38, a temperature adjusting door
actuator motor 39 and a blow mode switching door actuator motor
40 are also connected to corresponding output terminals of the air
conditioning device 30.
A dedicated heater control device 41 for controlling the electric
heaters 22, 23 of the seat air conditioning system is also provided.
A control signal from the seat air conditioning control panel 33
is inputted to the heater control device 41. The heater control
device 41 controls the heating power of each electric heater 22,
23 by controlling the voltage applied to the electric heater 22,
23 based on the control signal from the seat air conditioning control
panel 33. Electric power is supplied from the vehicle battery 34
to the heater control device 41 through the ignition switch 35 of
the vehicle engine.
The seat air conditioning control panel 33 will be described in
greater detail with reference to FIGS. 2 and 3. The seat air conditioning
control panel 33 is arranged near the instrument panel in the passenger
room. The seat air conditioning control panel 33 includes a right
seat air conditioning manipulation dial (hereinafter, simply referred
to as a right manipulation dial) 42 for the right seat (this is
the driver seat in a case of a vehicle with a right-hand steering
wheel) and a left seat air conditioning manipulation dial (hereinafter,
simply referred to as a left manipulation dial) 43 for the left
seat (this is the front non-driver seat in a case of the vehicle
with the right-hand steering wheel). The right and left manipulation
dials (each serving as a manipulating means) 42, 43 can be manually
rotated by the occupant.
Since the right and left manipulation dials 42, 43 are substantially
identical with each other, FIGS. 2 and 3 only show the components
corresponding to the right manipulation dial 42 for the sake of
simplicity. Specifically, FIGS. 2 and 3 show a variable resistor
mechanism, which is operated through the right manipulation dial
42, and the blower units 13, 14 of the seat air conditioning system,
which are of the right seat.
On the backside of the seat air conditioning control panel 33,
first and second movable conductor members 44, 45 are provided for
the right manipulation dial 42, and first and second movable conductor
members 46, 47 are provided for the left manipulation dial 43. In
FIGS. 2 and 3, the parenthesized numerals indicate components of
the variable resistor mechanism for the left manipulation dial 43.
Here, the first movable conductor member 44 and the second movable
conductor member 45 of the right manipulation dial 42 are electrically
insulated from each other and are mechanically, integrally connected
to each other, and the first movable conductor member 46 and the
second movable conductor member 47 of the left manipulation dial
43 are electrically insulated from each other and are mechanically
integrally connected to each other. Thus, the first and second movable
conductors 44, 45 rotate integrally with the right manipulation
dial 42, and the first and second movable conductors 46, 47 rotate
integrally with the left manipulation dial 43.
Two variable resistors, i.e., a first variable resistor 48 (50)
for supplying an input to the air conditioning control device 30
and a second variable resistor 49 (51) for supplying an input to
the heater control device 41 are provided to each manipulation dial
42 (43). A resistance value of each variable resistor 48, 49 (50,
51) varies according to an operational position of the manipulation
dial 42 (43). The first and second variable resistors 48, 49 (50,
51) of each manipulation dial 42 (43) have an arcuate shape and
are arranged adjacent to each other in two different imaginary planes,
respectively, within a rotatable range (about 200 degrees in the
case of FIG. 3) of the first and second movable conductor members
44, 45 (46, 47), or within a movable range of the manipulating dial
42 (43). The first movable conductor member 44 (46) is electrically
connected to an intermediate terminal 48a (50a) of the first variable
resistor 48 (50). Furthermore, the second movable conductor member
45 (47) is electrically connected to a terminal 49a (51a) of the
second variable resistor 49 (51).
With reference to FIG. 3, when the manipulation dial 42 (43) is
positioned to an OFF position 42a (43a), which is an intermediate
point in the rotatable range (i.e., movable range) of the manipulation
dial 42 (43), the intermediate terminal 48a (50a) of the first variable
resistor 48 (50) has a predetermined intermediate electric potential.
When the air conditioning control device 30 detects this intermediate
electric potential, the air conditioning control device 30 outputs
a stop (OFF) signal to the corresponding blower units 13, 14.
Furthermore, when the manipulation dial 42 (43) is placed in a
left side air flow manipulation range 42b (43b) shown in FIG. 3,
the air conditioning control device 30 outputs an air flow rate
control signal, which changes the air flow rate of the blower units
13, 14 in a manner shown in FIG. 5 (described in greater detail
below) based on a variation in the resistance value of the first
variable resistor 48 (50), i.e., a variation in the electric potential
of the intermediate terminal 48a (50a) in the air flow manipulation
range 42b (43b).
On the other hand, the second variable resistor 49 (51) is electrically
turned off when the manipulation dial 42 (43) is positioned in the
left side air flow manipulation range 42b (43b) located on the left
side in FIG. 3 or when the manipulation dial 42 (43) is position
in the OFF position 42a (43a). In this way, when the manipulation
dial 42 (43) is positioned in the left side air flow manipulation
range 42b (43b) or in the OFF position 42a (43a), the heater control
device 41 outputs the OFF signal to turn off the power supply to
the corresponding electric heaters 22, 23.
When the manipulation dial 42 (43) is positioned in a right side
heater manipulation range 42c (43c) shown in FIG. 3, the air conditioning
control device 30 outputs an air flow rate control signal, which
changes the air flow rate of the corresponding blower units 13,
14 in the manner shown in FIG. 5 (described in greater detail below)
based on a variation in the resistance value of the first variable
resistor 48 (50), i.e. a variation in the electric potential of
the intermediate terminal 48a (50a) in the heater manipulation range
42c (43c). Furthermore, the heater control device 41 controls the
voltage applied to the electric heaters 22, 23 to slightly increase
the heater heating power of the electric heaters 22, 23 by a relatively
small amount based on a variation in the resistance value of the
second variable resistor 49 (51), i.e., a variation in the electric
potential of the terminal 49a (51a) in the heater manipulation range
42c (43c), as shown in FIG. 5.
The air conditioning control device 30 has duty control capability
for performing duty control of the voltage applied to the motor
of the blower of the passenger room air conditioning unit 21 to
control the air flow rate of the blower of the passenger room air
conditioning unit 21. Thus, in the first embodiment, the duty control
capability of the air conditioning control device 30 is used to
perform duty control of the voltage applied to the fan drive motor
13a, 14a to control the air flow rate of the seat blower units 13,
14.
Next, operation according to the first embodiment will be described
with reference to FIGS. 4 and 5. FIG. 4 is a flow chart showing
the air flow rate control of the blower unit 13, 14 performed by
the air conditioning control device 30 and the heating power control
of the electric heaters 22, 23 performed by the heater control device
41. FIG. 5 shows the air flow rate of the blower unit 13, 14 of
the seat air conditioning system and the heater heating power (W)
relative to the position of the manipulation dial 42, 43.
First, at step S10, it is determined whether the current operational
position of the corresponding manipulation dial 42, 43 is in the
OFF position 42a, 43a, which is the intermediate position. When
it is determined that the current operational position of the manipulation
dial 42, 43 is in the OFF position 42a, 43a, control proceeds to
step S20. At step S20, both the blower units 13, 14 and the electric
heaters 22, 23 are turned off.
When it is determined that the current operational position of
the manipulation dial 42, 43 is not in the OFF position 42a, 43a
at step S10, control proceeds to step S30. At step S30, it is determined
whether the current operational position of the manipulation dial
42, 43 is in the air flow manipulation range 42b, 43b. When it is
determined that the current operational position of the manipulation
dial 42, 43 is in the air flow manipulation range 42b, 43b, control
proceeds to step S40. At step S40, each blower unit 13, 14 is actuated
such that the air flow rate of the blower unit 13, 14 is controlled
and adjusted to the air flow rate that corresponds to the operational
position of the manipulation dial 42, 43, and each electric heater
22, 23 is kept off.
Specifically, the air flow rate control is performed as follows.
That is, when the manipulation dial 42, 43 shown in FIG. 3 is rotated
to the left end position, the air flow rate of the blower unit 13,
14 is shifted to the maximum value (Hi), as shown in FIG. 5. Then,
when the manipulation dial 42, 43 is rotated from the left end position
in the right direction (clockwise direction), i.e., when the operational
position of the manipulation dial 42, 43 is shifted toward the OFF
position 42a, 43a, the air flow rate of the blower unit 13, 14 is
reduced toward the minimum value (Lo). This flow rate control can
be accomplished in the following manner. That is, the air conditioning
control device 30 determines a variation in the electric potential
of the intermediate terminal 48a, 50a and controls the voltage applied
to the drive motor 13a, 14a of each blower unit 13, 14 based on
the variation in the electric potential of the intermediate terminal
48a, 50a to control the rotational speed of the drive motor 13a,
14a.
When it is determined that the current operational position of
the manipulation dial 42, 43 is not in the air flow manipulation
range 42b, 43b at step S30, the operational position of the manipulation
dial 42, 43 should be in the heater manipulation range 42c, 43c.
In this case, control proceeds to step S50 where the heating power
of the electric heater 22, 23 is controlled and adjusted to the
heating power that corresponds to the operational position of the
manipulation dial 42, 43.
Specifically, this heating power control is performed as follows.
That is, when the manipulation dial 42, 43 is rotated to the right
end position, the heating power of the electric heater 22, 23 is
shifted to the maximum value (Hi), as shown in FIG. 5. Then, when
the manipulation dial 42, 43 is rotated from the right end position
in the left direction (counterclockwise direction), i.e., when the
operational position of the manipulation dial 42, 43 is shifted
toward the OFF position 42a, 43a, the heating power of the electric
heater 22, 23 is reduced toward zero (OFF). This heating power control
can be accomplished in the following manner. That is, the heater
control device 41 determines a variation in the electric potential
of the terminal 49a, 51a and controls the voltage (power consumption)
applied to each electric heater 22, 23 based on the variation in
the electric potential of the terminal 49a, 51a.
Next, at step S60, it is determined whether the heating power of
the electric heater 22, 23, which is determined by the operational
position of the manipulation dial 42, 43, is greater than a predetermined
value Q1 (FIG. 5). When it is determined that the heating power
of the electric heater 22, 23 is equal to or less than the predetermined
value Q1, control proceeds to step S70. At step S70, the blower
unit 13, 14 is turned off.
On the other hand, when it is determined that the heating power
of the electric heater 22, 23 is greater than the predetermined
value Q1, control proceeds to step S80. At step S80, it is determined
whether the inside air temperature TR is greater than a predetermined
temperature TR1 (e.g., 23 degrees Celsius). When it is determined
that the inside air temperature TR is equal to or less than the
predetermined temperature TR1, control proceeds to step S90 where
the blower unit 13, 14 is turned off.
When the inside air temperature TR is greater than the predetermined
temperature TR1 (e.g., 23 degrees Celsius), control proceeds to
step S100 where the air flow rate of the blower unit 13, 14 is controlled
to correspond with the operational position of the manipulation
dial 42, 43. Specifically, this air flow rate control is performed
as follows. That is, when the manipulation dial 42, 43 is rotated
to a position where the heater heating power coincides with the
predetermined value Q1, the air flow rate of the blower unit 13,
14 becomes minimum value (Lo), as shown in FIG. 5. Then, when the
manipulation dial 42, 43 is rotated from this operational position
of the manipulation dial 42, 43 in the right direction (increasing
direction for increasing the heater heating power), the air flow
rate of the blower unit 13, 14 is slightly increased by a relatively
small amount from the minimum value (Lo).
This relatively small increased amount (or simply called as a relatively
small increase) of the air flow rate of the blower unit 13, 14,
which is synchronized with the increase of the heater heating power,
is preferably limited to at most about 40% of the minimum value
(Lo) to restrain cold air blow, which could be induced by an excessively
high air flow rate.
Next, advantages of the first embodiment will be described. In
the vehicle seat air conditioning system, which includes both the
electric heaters 22, 23 and the blower units 13, 14, the heater
heating power and the air flow rate can be set by rotating the single
manipulation dial 42, 43. Thus, the operation of the operator is
simplified, improving the operability of the system. Furthermore,
since there is only one manipulating member to set the heater heating
power and the air flow rate, the manipulating member can be produced
at the reduced cost, and the accommodating space for accommodating
the manipulating member can be reduced.
Furthermore, in the vehicle, as described above, the heating power
of the electric heater 22, 23 accommodated in the seat is normally
set to a relatively small value, i.e., about 60 to 90 W due to the
limitation imposed by the balance between the amount of charged
electricity and the amount of discharged electricity at the vehicle
battery 34. Thus, when the air is blown by the blower unit 13, 14
at the excessively high air flow rate relative to the heating power
of the electric heater 22, 23, the temperature of the blown air
cannot rise to a sufficient level. Thus, the cold blown air is discharged
around the occupant seated on the seat 10, deteriorating feeling
of warmness of the occupant.
However, according to the first embodiment, as shown in FIG. 5,
when the heating power of the electric heater 22, 23 is equal to
or less than the predetermined value Q1, the blower unit 13, 14
is stopped at step S70 to stop the blowing of the air from the seat
10. Thus, deterioration of feeling of the warmness caused by the
cold air can be prevented.
Furthermore, when the temperature in the passenger room, i.e.,
the inside air temperature TR is relatively low, the cold inside
air, which is located inside the passenger room, is drawn and blown
by the blower units 13, 14, so that the temperature of the blown
air from the seat 10 does not easily increase, and thus the cold
air is likely blown toward the passenger. Also, when the inside
air temperature is relatively low, the passenger becomes sensitive
to the annoyance induced by blowing of the cold air. Thus, in the
first embodiment, when the inside air temperature TR is equal to
or less than the predetermined temperature TR1 (e.g., 23 degrees
Celsius), the blower units 13, 14 are stopped at step S90 to stop
blowing of the air from the seat 10 irrespective of the heater heating
power determined by the operational position of the manipulation
dial 42, 43. In this way, the deterioration of the feeling of warmness,
which could be induced by blowing of the cold air, can be effectively
prevented when the inside temperature in the passenger room is relatively
low.
When the heating power of the electric heater 22, 23 is greater
than the predetermined value Q1, the air flow rate of the blower
unit 13, 14 is increased in correspondence with the heating power
of the electric heater 22, 23, so that the appropriate flow rate
of warm air, which is suitable to the current heating power of the
electric heater 22, 23, can be achieved.
(Second Embodiment)
In the first embodiment, the heating power of the electric heater
22, 23 is judged at step S60, and the inside air temperature TR
is judged at step S80. When the heater heating power is equal to
or less than the predetermined value Q1, the blower units 13, 14
are stopped. Also, when the inside air temperature TR is equal to
or less than the predetermined temperature TR1, the blower units
13, 14 are stopped. In a second embodiment, as shown in FIG. 6,
steps S60, S80 of the first embodiment are eliminated, and there
is provided step S65 for judging an elapsed time period of the electric
heater 22, 23 after initiation of energization of the electric hater
22, 23 is provided.
When it is determined that the elapsed time period t after initiation
of energization of the electric heaters 22, 23 is equal to or less
than a predetermined time period t1 (e.g., 10 minutes) at step S65,
control proceeds to step S70. At step S70, the blower units 13,
14 are stopped. On the other hand, when it is determined that the
elapsed time period t after the initiation of energization of the
electric heaters 22, 23 is greater than the predetermined time period
t1 at step S65, control proceeds to step S100. At step S100, the
blower units 13, 14 are activated and controlled to provide the
air flow rate that coincides with the operational position of the
manipulation dial 42, 43.
In the second embodiment, when the predetermined time period t1
(e.g., 10 minutes) has elapsed after the initiation of energization
of the electric heaters 22, 23, the heating temperature of each
electric heater 22, 23 should be raised to and stabilized at a predetermined
temperature, which coincides with the heating power of the electric
heater 22, 23. Thus, when the blower units 13, 14 are activated
upon the stabilization of the heating temperature of the electric
heater 22, 23, blowing of the cold air right after the initiation
of energization of the electric heaters 22, 23 during air temperature
rising period can be advantageously prevented. Thus, deterioration
of feeling of warmness of the occupant can be prevented.
(Third Embodiment)
In the first embodiment, only the inside air temperature TR is
judged at step S80. When it is determined that the inside air temperature
TR is equal to or less than the predetermined temperature TR1 at
step S80, the blower units 13, 14 are stopped. Contrary to this,
in a third embodiment of the present invention, at step S80 in FIG.
7, it is determined whether the following two conditions are both
satisfied. The first condition is that the inside air temperature
TR is greater than the predetermined temperature TR1. The second
condition is that a target outlet air temperature TAO is greater
than a predetermined temperature TAO1.
As is known in the art, the target outlet air temperature TAO is
the target temperature of the air discharged from the passenger
room air conditioning unit 21 into the passenger room and is necessary
to maintain the passenger room air temperature (inside air temperature)
TR at a selected passenger room air temperature Tset irrespective
of a variation in the air conditioning heat load of the vehicle.
The selected passenger room air temperature Tset is selected and
is set through the target air temperature setting switch 32a of
the air conditioning control panel 32.
As is known in the art, the target outlet air temperature TAO is
computed by the air conditioning control device 30 based on the
selected passenger room air temperature Tset, the inside air temperature
TR, the outside air temperature TAM and the amount of solar radiation
TS. The target outlet air temperature TAO is used as the basic target
value for the automatic air conditioning control.
In the heating operation where the electric heaters 22, 23 are
energized, the target outlet air temperature TAO is increased in
synchronism with increase of the heating heat load to maintain the
room temperature at the selected passenger room air temperature
Tset.
In the heating operation where the electric heaters 22, 23 are
energized, when one of the inside air temperature TR and the target
outlet air temperature TAO is equal to or less than the corresponding
predetermined value TR1, TAO1, NO is returned at step S80, and control
proceeds to step S90. At step S90, the blower units 13, 14 are stopped.
On the other hand, when both the inside air temperature TR and the
target outlet air temperature TAO are greater than the corresponding
predetermined value TR1, TAO1, YES is returned at step S80. Thus,
control proceeds to step S100 where the air flow rate is controlled
to correspond with the operational position of the manipulation
dial 42, 43.
In the first embodiment, when the inside air temperature TR is
greater than the predetermined temperature TR1, control proceeds
to step S100 where the blower units 13, 14 are activated. When the
target outlet air temperature TAO is equal to or less than the predetermined
temperature TAO1 (e.g., 40 degrees Celsius), and thus the heating
heat load of the entire vehicle is substantially small, the blow
mode of the passenger room air conditioning unit 21 is normally
automatically shifted from the foot mode to the bi-level mode in
synchronism with decrease of the target outlet air temperature TAO.
When the bi-level mode is set, the foot side (lower side) outlet
air temperature becomes higher than the face side (upper side) outlet
air temperature in the passenger room air conditioning unit 21 to
provide a corresponding temperature distribution where a relatively
low temperature zone is formed around a head of the occupant and
a relatively high temperature zone is formed around feet of the
occupant. Thus, when the warm air is blown from the seat 10 during
the bi-level mode, this temperature distribution is likely disturbed,
resulting in deterioration of feeling of warmness during the bi-level
mode operation of the passenger room air conditioning unit 21.
Accordingly, in the third embodiment, the blower units 13, 14 are
activated only when both the inside air temperature TR and the target
outlet air temperature TAO are greater than the corresponding predetermined
value TR1, TAO1. Therefore, in the predetermined TAO temperature
condition (e.g., equal to or less than 40 degrees Celsius) where
the bi-level mode is selected and is set in the passenger room air
conditioning unit 21, the blower units 13, 14 can be stopped to
stop blowing of the warm air from the seat 10. In this way, deterioration
of feeling of warmness during the bi-level mode operation of the
passenger room air conditioning unit 21 can be prevented.
(Other Embodiments)
In each of the first to third embodiments, the air flow rate of
each blower unit 13, 14 is controlled to coincide with the operational
position of the corresponding manipulation dial 42, 43 at step S100.
Alternatively, the air flow rate of each blower unit 13, 14 can
be controlled to coincide with the heating heat load at step S100.
Specifically, the heating heat load can be determined based on
the target outlet air temperature TAO, which is computed by the
air conditioning control device 30 and servers as an informational
value indicating the corresponding heating heat load of the entire
vehicle. During the heating operation where the electric heaters
22, 23 are energized, the target outlet air temperature TAO is increased
as the heating heat load is increased.
Thus, at step S100, the air flow rate of each blower unit 13, 14
can be controlled as follows. That is, when the target outlet air
temperature TAO is increased to cause an increase in the heating
heat load, the air flow rate of each blower unit 13, 14 is accordingly
increased. In this way, when the heating heat load is increased,
the air flow rate of the warm air from the seat 10 can be automatically
increased to improve feeling of warmness of the occupant.
Even in this instance, the increase of the air flow rate of the
blower unit 13, 14, which is in synchronism with the increase of
the heating heat load, is preferably limited to at most about 40%
of the minimum value (Lo) to restrain cold air blow induced by the
excessively high flow rate.
In each of the first to third embodiments, the resistance value
of the first variable resistor 48, 50, which is used as the input
(for controlling the air flow rate) to the air conditioning control
device 30, and the resistance value of the second variable resistor
49, 51, which is used as the input (for controlling the heating
power) to the heater control device 41, are changed synchronously
with rotation of the manipulation dial 42, 43, which is manipulated
by the occupant. Alternatively, a lever-like member, which can be
linearly reciprocated upon manipulation thereof, can be used as
a manipulating means for manipulating the first and second variable
resistors 48-51.
Furthermore, in each of the first to third embodiments, the first
variable resistor 48, 50 is used as an air flow rate command signal
generating means for outputting the variable flow rate command signal,
which commands the air flow rate of the seat blower unit 13, 14,
and the second variable resistor 49, 51 is used as a heating power
command signal generating means for outputting the variable heating
power command signal, which commands the heating power of the seat
electric heater 22, 23. In place of the variable resistors, two
types of switches, which are opened and closed synchronously with
manipulation of a single manipulating means, can be provided. In
such a case, the air flow rate command signal and the heating power
command signal can be generated based on open and close signals
of the two switches.
Furthermore, the air conditioning control device 30 and the heater
control device 41 can be integrated as a single control device.
Additional advantages and modifications will readily occur to those
skilled in the art. The invention in its broader terms is therefore
not limited to the specific details, representative apparatus, and
illustrative examples shown and described. |