Machine tools abstract
A work fixing jig for machine tools is attached to a table of the
machine tool utilizing a mount bore formed in a work fixing surface
of the table for use in fixing work to the table by work fixing
means. The jig comprises a jig main body, a generally cylindrical
engaging member attached to the jig main body and insertable into
the mount bore of the table, a rod movable upward or downward relative
to the jig main body and extending through the engaging member,
a spring for biasing the rod upward relative to the jig main body,
and a cylinder for moving the rod downward against the biasing force
of the spring. An elastic ring is fitted around the engaging member
for diametrically contracting the lower end portion thereof. The
rod has a large-diameter portion for diametrically expanding the
lower end portion to bring engaging lugs into engagement with a
portion of the table when positioned inside the engaging member.
When the large-diameter portion is moved out of the engaging member
to therebelow, the elastic force of the ring diametrically contracts
the lower end portion of the engaging member to disengage the engaging
lugs. Work can be fixed to the table easily with use of the jig.
Machine tools claims
What is claimed is:
1. A work fixing jig for machine tools which is to be attached
to a work fixing member of the machine tool utilizing a mount bore
formed in a work fixing surface of the fixing member for use in
fixing work to the fixing member by work fixing means, the jig comprising
a jig main body having a contact surface to be brought into intimate
contact with the work fixing surface, an engaging member projecting
from the contact surface of the jig main body and insertable into
the mount bore of the fixing member, the engaging member having
an engaging portion releasably engageable with a portion of the
fixing member defining an opening of the mount bore opposite to
the work fixing surface, a rod movable in directions orthogonal
to the contact surface relative to the jig main body, disengaging
means provided between the engaging member and the rod for engaging
the engaging portion of the engaging member with the opening-defining
portion and disengaging the engaging portion from the opening-defining
portion by the axial movement of the rod, biasing means provided
between the jig main body and the rod for biasing the rod into the
engaging movement, and a fluid pressure cylinder provided between
the jig main body and the rod for bringing the rod into the disengaging
movement against the biasing force of the biasing means.
2. A work fixing jig for machine tools according to claim 1 wherein
the work fixing means comprises a clamp fitted around an end of
the rod opposite to the engaging member and movable axially of the
rod, the clamp having a threaded through bore at one end thereof
and a work holding portion at the other end thereof, a concave seat
provided on the jig main body and having a concave face opposed
to the clamp, and an adjusting bolt screwed in the threaded bore
of the clamp from the jig main body side and having a head provided
with a convex face, the convex face being opposed to the jig main
body and receivable by the concave face of the concave seat.
3. A work fixing jig for machine tools according to claim 1 wherein
the engaging member is generally in the form of a hollow cylinder
and provided at a forward end portion thereof with the engaging
portion engageable with the opening-defining portion of the work
fixing member, the end portion providing the engaging portion being
diametrically contractable or expandable, the engaging portion being
engageable with the opening-defining portion of the work fixing
member when said end portion providing the engaging portion is diametrically
expanded, the engaging portion being disengageable from the opening-defining
portion when said end portion is diametrically contracted, the engaging
member having an elastic ring fitted therearound for diametrically
contracting said end portion, the rod being inserted through the
engaging member, the rod having a large-diameter portion for diametrically
expanding said end portion when positioned inside the engaging member,
the large-diameter portion permitting said end portion of the engaging
member to be diametrically contracted by the elastic force of the
elastic ring when moving out of the engaging member.
4. A work fixing jig for machine tools according to claim 1 wherein
an inner periphery of the engaging member has at an end portion
thereof providing the engaging portion a tapered surface flaring
toward an extremity, and the rod has a large-diameter portion provided
with opposite end faces tapered toward respective ends thereof.
5. A work fixing jig for machine tools according to claim 1 wherein
the mount bore of the work fixing member is cylindrical, and the
contact surface of the jig main body is provided with an annular
projection around a through bore for the rod to extend therethrough,
the annular projection having an outward flange at an outer end
thereof, the engaging member comprising the combination of component
pieces each generally in the form of a segment of a hollow cylinder
and each having an outer peripheral surface of the same curvature
as an inner periphery defining the mount bore, the combination being
generally in the form of a hollow cylinder in its entirety, each
of the component pieces having an engaging portion projecting outward
from one end thereof and releasably engageable with the opening-defining
portion of the work fixing member, each component piece having a
groove formed in an inner peripheral surface thereof at the other
end and extending circumferentially of the combination and a groove
formed in its outer peripheral surface at a portion thereof close
to the engaging portion and extending circumferentially of the combination,
the outward flange of the annular projection being fitted in the
grooves in the inner peripheral surfaces of all the component pieces
and an elastic ring being fitted in the grooves in the outer peripheral
surfaces of all the component pieces, whereby an end portion of
the engaging member providing the engaging portions is made diametrically
contractable or expandable.
Machine tools description
BACKGROUND OF THE INVENTION
The present invention relates to a jig to be mounted on the work
fixing member of a machine tool utilizing a mount bore formed in
a work fixing surface of the fixing member for use in fixing work
to the fixing member by work fixing means.
Work is fixed to a work fixing surface of a table (work fixing
member) of a machine tool conventionally, for example, by an arrangement
shown in FIG. 5. With reference to FIG. 5 a table 1 has a plurality
of threaded bores 2 extending from a flat upper surface 1a (work
fixing surface) thereof to a flat lower surface 1b thereof. A jig
main body 3 in the form of a vertical rod and having screw portions
3a, 3b at respective opposite ends thereof has its lower screw portion
3a screwed in the threaded bore 2 at a suitable position and is
fixed to the table 1 with a lock nut 4 screwed on the screw portion
3a. A clamp 5 for fixing work W has a threaded bore 5a at a base
end thereof and a through bore 5b at an intermediate portion of
the length thereof. An adjusting bolt 6 is screwed in the threaded
bore 5a from below, and the upper screw portion 3b of the jig main
body 3 loosely extends through the bore 5b. The adjusting bolt 6
has a head 6a having a convex lower face. The head 6a rests on a
concave seat 7 having a concave upper face and provided on the table
1. The clamp 5 adjusting bolt 6 and concave seat 7 provide work
fixing means. The work W is fixed to the upper surface 1a of the
table 1 by placing a forward end of the clamp 5 on the work W as
positioned in place on the table 1 and screwing a clamp nut 8 on
the upper threaded portion 3b of the jig main body 3. The work fixing
means comprises the clamp 5 adjusting bolt 6 concave seat 7 and
clamp nut 8.
However, in the case where the work W is to be fixed to the upper
surface 1a of the table 1 as shown in FIG. 5 the lower screw portion
3b of the jig main body 3 must be screwed into the threaded bore
2 to a controlled depth by a cumbersome procedure, and a tool is
necessary for screwing the lower screw portion 3b of the jig main
body 3 into the threaded bore 2. Fixing the jig main body 3 to the
table 1 therefore requires much time and labor, hence the problem
that the overall procedure for fixing the work W is cumbersome.
DISCLOSURE OF THE INVENTION
An object of the present invention is to solve the above problem
and to provide a work fixing jig for machine tools by which work
can be fixed to the tool more easily than conventionally.
The present invention provides a work fixing jig for machine tools
which is to be attached to a work fixing member of the machine tool
utilizing a mount bore formed in a work fixing surface of the fixing
member for use in fixing work to the fixing member by work fixing
means, the jig comprising a jig main body having a contact surface
to be brought into intimate contact with the work fixing surface,
an engaging member projecting from the contact surface of the jig
main body and insertable into the mount bore of the fixing member,
the engaging member having an engaging portion releasably engageable
with a portion of the fixing member defining an opening of the mount
bore opposite to the work fixing surface, a rod movable in directions
orthogonal to the contact surface relative to the jig main body,
disengaging means provided between the engaging member and the rod
for engaging the engaging portion of the engaging member with the
opening-defining portion and disengaging the engaging portion from
the opening-defining portion by the axial movement of the rod, biasing
means provided between the jig main body and the rod for biasing
the rod into the engaging movement, and a fluid pressure cylinder
provided between the jig main body and the rod for bringing the
rod into the disengaging movement against the biasing force of the
biasing means.
The term the "mount bore" used above is to be interpreted
as including a mount groove.
The work fixing jig of the invention for machine tools is used
in the following manner for fixing work in place. A fluid is supplied
to one of the fluid compartments of the fluid pressure cylinder
to move the rod for disengagement against the biasing force of the
biasing means to release the engaging portion of the engaging member
from an engaged state. In this state, the engaging member is fitted
into the mount bore of the work fixing member. The pressure fluid
is then discharged from the fluid compartment of the cylinder, permitting
the biasing force of the biasing means to bring the rod into the
engaging movement, whereby the engaging portion of the engaging
member is brought into engagement with the opening-defining portion
of the work fixing member. In this way, the jig main body is fixed
to the fixing member for the work fixing means to fix the work in
position.
The contact surface of the jig main body is brought into intimate
contact with the work fixing surface of the fixing member, whereby
the depth to which the engaging member is fitted into the mount
bore of the fixing member is determined in accordance with the depth
of the mount bore and the length of the engaging member. This eliminates
the need to control the depth of fitting. Unlike the conventional
case wherein the screw portion of the jig main body is screwed into
the threaded bore in fixing the jig main body to the work fixing
member, the jig main body of the invention can be fixed to the work
fixing member without necessitating any cumbersome procedure. The
overall work fixing procedure can therefore be made more simplified
than when the conventional jig is used.
The work fixing jig of the invention for machine tools may be so
adapted that the engaging member is generally in the form of a hollow
cylinder and provided at a forward end portion thereof with the
engaging portion engageable with the opening-defining portion of
the work fixing member, the end portion providing the engaging portion
being diametrically contractable or expandable, the engaging portion
being engageable with the opening-defining portion of the work fixing
member when said end portion providing the engaging portion is diametrically
expanded, the engaging portion being disengageable from the opening-defining
portion when said end portion is diametrically contracted, the engaging
member having an elastic ring fitted therearound for diametrically
contracting said end portion, the rod being inserted through the
engaging member, the rod having a large-diameter portion for diametrically
expanding said end portion when positioned inside the engaging member,
the large-diameter portion permitting said end portion of the engaging
member to be diametrically contracted by the elastic force of the
elastic ring when moving out of the engaging member.
In this case, the engaging member and the disengaging means become
relatively simple in construction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in vertical section and showing a work fixing
jig of the invention before it is attached to a table;
FIG. 2 is a perspective view showing on an enlarged scale an engaging
member of the work fixing jig of the invention;
FIG. 3 is a view in vertical section and showing the work fixing
jig of the invention as attached to the table;
FIG. 4 is a view in vertical section and showing work as fixed
to the table by the work fixing jig of the invention; and
FIG. 5 is a view in vertical section and showing work as fixed
to a table by a conventional work fixing jig.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a work fixing jig before it is attached to a table,
FIG. 2 shows an engaging member on an enlarged scale, FIG. 3 shows
the jig as attached to the table, and FIG. 4 shows work as fixed
to the table.
In the following description, the upper and lower sides of FIGS.
1 to 4 will be referred to as upper and lower, respectively. Further
throughout the drawings, like parts are designated by like reference
numerals.
With reference to FIG. 1 a table 1 has instead of the threaded
bores 2 a plurality of cylindrical mount bores 10 extending therethrough
from the upper surface 1a thereof to the lower surface thereof 1b.
Utilizing the mount bore 10 the work fixing jig is attached to
the table 1. The jig comprises a jig main body 11 in the form of
a block and having a flat lower surface 11a (intimate contact surface)
fittable to the upper surface 1a of the table 1 in intimate contact
therewith, an engaging member 12 generally in the form of a cylinder
and attached to the lower surface 11a of the main body 11 in a downwardly
projecting manner, a vertical rod 13 extending through the jig main
body 11 upwardly and downwardly movably and extending through the
engaging member 12 upwardly and downwardly movably, a compression
coiled spring 14 (biasing means) for biasing the rod 13 upward relative
to the jig main body 11 and a single-acting pneumatic cylinder
15 provided between the jig main body 11 and the rod 13 for moving
the rod 13 downward relative to the jig main body 11 against the
biasing force of the spring 14.
An annular downward projection 16 is formed on the lower surface
11a of the jig main body 11 integrally therewith around a through
bore 11b for the rod 13 to extend therethrough. The projection 16
is integrally provided with an outward flange 16a at its lower end.
As shown in FIG. 2 the engaging member 12 comprises the combination
of component pieces 17 each generally in the form of a segment of
a hollow cylinder and having an outer periphery of the same curvature
as the inner periphery of the mount bore 10 the combination being
generally in the form of a hollow cylinder in its entirety. The
component pieces 17 have a slightly larger length than the mount
bore 10 such that the lower end of the jig main body 11 projects
downward beyond the bore 10 when the lower surface 11a of the body
11 is brought into intimate contact with the upper surface 1a of
the table 1. Each component piece 17 has an engaging lug 18 (engaging
portion) formed integrally with its lower end and engageable with
the inner peripheral portion of lower surface of the table 1 defining
the mount bore 10 when the engaging member 12 is inserted into the
mount bore 10 with the outer peripheral surfaces of the component
pieces 17 in intimate contact with the inner periphery defining
the bore 10. The component piece 17 has in the inner surface of
an upper end portion thereof a groove 17a extending circumferentially
of the combination and having the outward flange 16a of the downward
projection 16 fitted therein. The component piece 17 further has
a groove 17b extending in the circumferential direction and formed
in a lower portion of outer surface thereof. The outward flange
16a of the downward projection 16 is fitted into the inner groove
17a of all the component pieces 17 and an elastic ring 19 is fitted
into the outer grooves 17b of the pieces 17 whereby all the component
pieces 17 are attached to the jig main body 11 to provide the engaging
member 12. The lower end of the engaging member 12 is diametrically
contractable or expandable. The elastic ring 19 has the same structure
as an O-ring. The curvature of the lower portion of inner surface
of each component piece 17 gradually decreases as this portion extends
downward, with the result that the lower portion of inner periphery
of the engaging member 12 has a tapered surface 12a flaring downward
with a diameter gradually increasing downward.
The rod 13 has at its lower end a large-diameter portion 20 having
an outer periphery with the same curvature as the inner periphery
of the engaging member 12. The large-diameter portion 20 has upper
and lower faces 20a, 20b tapered upward and downward respectively.
The large-diameter portion 20 projects downward beyond the lower
end of the engaging member 12 when the rod 13 is brought to a lower
limit position, and has its upper part positioned above the inner
peripheral tapered surface 12a of the engaging member 12 when the
rod 13 is brought to an upper limit position. When the large-diameter
portion 20 is projected downward beyond the lower end of the engaging
member 12 the engaging member 12 has its lower end portion diametrically
contracted by the action of the elastic ring 19 and the engaging
lugs 18 are movable through the mount bore 10 in this state (see
FIG. 1). When the rod 13 is brought to its upper limit position,
the engaging member 12 is diametrically enlarged by the large-diameter
portion 20 bringing the outer periphery thereof into intimate contact
with the inner periphery of the table 1 defining the mount bore
10 and engaging the lugs 18 with the inner peripheral portion of
the table lower surface 1b around the bore 10 (see FIG. 3). The
rod 13 has at its upper end a screw portion 13a, which loosely extends
through a clamp 5 at a through bore 5b, with a clamp nut 8 screwed
on its upper end. The compression coiled spring 14 is fitted around
the rod 13 as positioned between the jig main body 11 and the clamp
5.
The pneumatic cylinder 15 is provided between the jig main body
11 and the rod 13 in the following manner. The through bore 11b
of the jig main body 11 for the rod 13 to extend therethrough is
diametrically enlarged except at the bore lower end portion to provide
a cylinder chamber 21. The bore 11b has an upper-end opening which
is closed with a closure 22 screwed in the bore 11b. The rod 13
extends through the closure 22 hermetically. A piston portion 23
is provided on the portion of the rod 13 positioned within the cylinder
chamber 21. The vertical length of the cylinder chamber 21 i.e.,
the stroke length of the piston portion 23 is so determined that
when the piston portion 23 is brought to its lower limit position,
the large-diameter portion 20 projects downward beyond the lower
end of the engaging member 12 and that when the piston portion
23 is brought to its upper limit position, the rod 13 has it lower
end positioned at the same level as the lower end of the engaging
member 12 and has the upper part of its large-diameter portion 20
positioned above the inner peripheral tapered surface 12a of the
engaging member 12. The jig main body 11 has a pressure air channel
24 having an end opening in the inner periphery of the cylinder
chamber 21 immediately under the closure 22 and another end opening
in an outer side of the jig main body 11. Attached to the end of
the air channel 24 in the outer side of the body 11 is one joint
member 25a of a removable pipe joint 25 which is termed a snap-in
joint. The other joint member 25b of the pipe joint 25 is attached
to an end of a pressure air supply hose 26. The hose 26 is connected
to the jig main body 11 by these joint members 25a, 25b for supplying
pressure air to the air channel 24 through the hose 26. A known
joint is used as the removable pipe joint 25 the construction of
which therefore will not be described.
Using the work fixing jig of the above construction, the work W
is fixed to the table 1 in the following manner.
The work W is placed on the table 1 in advance, as positioned in
place with respect to the horizontal direction. First, the hose
26 is connected to the jig main body 11 and pressure air is supplied
to an air compartment 21a in the cylinder chamber 21 of the pneumatic
cylinder 15 above the piston portion 23 to lower the rod 13 to its
lower limit position relative to the jig main body 11. This causes
the large-diameter portion 20 of the rod 13 to project downward
beyond the lower end of the engaging member 12 diametrically contracting
the lower end portion of the engaging member 12 (see FIG. 1). The
engaging member 12 in this state is inserted into the mount bore
10 at a suitable position, and the lower surface 11a of the jig
main body 11 is brought into intimate contact with the upper surface
1a of the table 1. The supply of pressure air to the air compartment
21a of the pneumatic cylinder 15 is then discontinued, and the hose
26 is removed from the jig main body 11 whereupon the rod 13 is
raised to its upper limit position relative to the main body 11
by the biasing force of the compression coiled spring 14. At this
time, the upper-end tapered face 20a of the large-diameter portion
20 of the rod 13 and the tapered surface 12a of the engaging member
12 act to permit the large-diameter portion 20 to be inserted into
the engaging member 12 smoothly. The pressure air within the air
compartment 21a escapes through the air channel 24. Upon the rod
13 reaching its upper limit position, the upper outer peripheral
part of the large-diameter portion 20 comes into intimate contact
with the portion of the inner periphery of the engaging member 20
above its tapered surface 12a, diametrically enlarging the lower
end portion of the engaging member 12. As a result, the engaging
lugs 18 are engaged with the inner peripheral portion of the table
lower surface 1b around the mount bore 10 to attach the jig to the
upper surface 1a of the table 1 (see FIG. 3). Finally, the clamp
nut 8 is advanced in screw-thread engagement with the rod 13 to
place the lower face of the head 6a of an adjusting bolt 6 on the
upper face of a concave seat 7 on the jig main body 11 and to cause
the forward end of the clamp 5 to hold the work W (see FIG. 4).
In this way, the work W is fixed to the upper surface 1a of the
table 1.
The foregoing embodiment has the pneumatic cylinder 15 between
the jig main body 11 and the rod 13 whereas a hydraulic cylinder
may alternatively be provided. The jig can be attached to the table
1 in the same manner as above in the case wherein the table 1 is
provided with mount grooves having a width equal to the diameter
of the mount bores 10 instead of the mount bores 10. |