JPH0121712Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> In high-performance NC machine tools such as machining centers, in order to increase the operating rate of the machine, a large number of workpieces are placed in predetermined positions on a change table on one side of the machine tool. The present invention relates to a workpiece fixing device for setting and fixing a workpiece in a predetermined posture, moving the workpiece in this state onto a table of a machine, accurately positioning and fixing the workpiece, and performing machining.

<Prior art> The present applicant has previously proposed a device of this type as shown in FIG. 6A.
and proposed what is shown in B.
issue).

That is, the reference receiving frame 14 is fixedly installed on the base plate 7, and the workpiece pressing frame 16 is removably attached opposite to this.
A fluid pressure cylinder 20 is arranged in parallel to this workpiece holding frame 16, and a clamping tool 22 is provided at the tip of the piston rod 21 via a spherical joint 23. There is one that is fixed by pressing against the receiving frame 14.

<Problems to be solved by the invention> With the structure as described above, when the width of the workpiece changes beyond the stroke Sa of the fluid pressure cylinder 20, the workpiece press frame 16 must be adjusted to match the width of the workpiece 4. It would have to be relocated, which would require a lot of effort and effort.

Furthermore, although the clamping tool 22 is swingably fixed to the tip of the piston rod 21 so as to follow the side surface of the workpiece, the set screw 35 of the clamping tool 22 becomes loose due to repeated use, and the workpiece pressing surface of the clamping tool 22 If it protrudes from 24, there is a risk of damaging the side surface of the workpiece 4 or the protection plate 24, or damaging the set screw 35.

In addition, each hydraulic cylinder 2 of the workpiece press frame 16
0 operate all at once, there is a problem in that the portion of the protection plate 34 that does not receive the workpiece 4 is pressed and bent by the clamp tool 22, as shown by the imaginary line C in FIG. 6A, for example.

<Means for solving the problem> The present invention was proposed in order to solve the above problem.A clamp support hole is formed in the tip of the piston rod of a fluid pressure cylinder, and a clamp support hole is provided in the tip of the clamp. In addition to forming a workpiece pressing surface, the base end portion is made spherical to form a support portion, and this support portion is configured to be removably attached to the clamp tool support hole via an elastic body.

<Function> When the width of the workpiece installed in the workpiece placement space changes, the workpiece fixing device configured as described above pulls out the clamping tool fitted into the clamping tool support hole of the piston rod of the fluid pressure cylinder, and fixes the workpiece. Replace with a clamp tool that matches the width and fit it in place.
When the hydraulic cylinder is actuated, the workpiece is firmly fixed.

Furthermore, if the clamping tool in the part where the workpiece is not attached is pulled out from the clamping tool support hole of the piston rod, the protective plate will not be pressed and bent by the clamping tool even if the fluid pressure cylinder is actuated to clamp the clamping tool.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

As shown in FIGS. 1 to 4, a two-sided workpiece fixing device 3 can be placed on a turntable 2 placed on the front side of a machine tool 1, and a pallet-shaped workpiece fixing device 3 can be placed thereon. After a large number of workpieces 4 are set, they are transported onto a table 5 of a machine tool 1, accurately positioned at a predetermined position, and then fixed, and the workpieces 4 are machined.

Therefore, the workpiece fixing device 3 is placed on the table 5.
Two running rails 6 are attached for traveling, and a positioning fitting hole (not shown) on the lower surface of the base plate 7 of the workpiece fixing device 3 carried in is attached to a fitting hole (not shown) for positioning device 8 consisting of a vertical hydraulic cylinder. 9, the base board 7 is accurately positioned.

On the other hand, the clamp claw 11 of the clamp device 10 consisting of a vertical hydraulic cylinder is loosely fitted into the T-groove for clamping on the lower surface of the base plate 7, allowing the base plate 7 to move in the front and rear direction.
After the base plate 7 is positioned by the positioning device 8, the clamp claw 11 is pulled down to lower the base plate 7, and the traveling means (not shown) is moved into the groove and supported and fixed on the support strip 12.

When the base plate 7 moves back and forth, in order to restrict its movement in the left and right direction, a travel guide rail 13 is fitted into the vertical groove of the T groove on the lower surface of the base plate 7 so as to be slidable back and forth.

The base plate 7 of the work fixing device 3 is made of a thick steel plate, and a reference receiving frame 14 is fixed to the center of the upper surface of the base plate 7 facing left and right, and a work placement space 15 is symmetrically provided in front and behind the reference receiving frame 14. Each workpiece press frame 16 is attached to the reference receiving frame 14 in parallel with and facing the reference frame 14 apart from each other.

This workpiece holding frame 16 is fixed to be movable back and forth with bolts or the like via a T-groove 17 on the upper surface of the base plate 7, so that the width of the workpiece placement space 15 can be adjusted as necessary.

As shown in FIG. 2, FIG. 3, and FIG. 4, a workpiece receiving surface 18 is formed on the front and rear surfaces of the reference receiving frame 14, and the workpiece receiving surface 18 is divided into a plurality of equal parts in the left and right direction so that each unit workpiece can be It is formed on the receiving surface 19.

A hydraulic cylinder 20 as shown in FIG. 5 is attached to the workpiece holding frame 16 at a position facing the slightly upper part of the central part of the unit workpiece receiving surface 19, and its piston rod 21 protrudes from the inner surface of the workpiece holding frame 10. A clamping tool 22 is attached to the tip of each piston rod 21 via a spherical contact portion 23 so as to be able to swing in all directions.

The hydraulic cylinder 20 is constructed by forming a cylinder assembly hole 28 diagonally downward in the workpiece press frame 16, and screwing into this cylinder assembly hole 28 a cylinder barrel 30 that slidably accommodates a piston 29. The assembly hole 28 is a pressure oil supply path (fluid pressure supply path) 3 formed through the workpiece press frame 16.
1 is communicated with a hydraulic oil chamber 32.

This hydraulic cylinder 20 is a single-acting type, and the piston 29 is pressed toward the unclamping side by a return spring 33 mounted inside the cylinder barrel 30.

In this embodiment, the fluid pressure cylinder 20 is formed of a hydraulic cylinder, but depending on the workpiece 4, a pneumatic cylinder may be used.

The clamp tool 22 has a workpiece pressing surface 24 formed at its distal end, and a spherical support section 25 formed at its base end.
5 is fitted with a single material 26 such as an O-ring.

This spherical support portion 25 is connected to the hydraulic cylinder 20
The clamping tool support hole 27 is recessed from the front end surface 21a of the piston rod 21 and is removably fitted therein.

The clamping tool 22 attached to the tip of the piston rod 21 is formed so that the length L from the front end surface of the piston rod 21 to the workpiece pressing surface 24 protruding is longer than the stroke S of the hydraulic cylinder 20.

By configuring the clamping tool 22 as described above, when the width of the workpiece 4 changes, the piston rod 21
If the hydraulic cylinder 20 is operated after replacing the hydraulic cylinder 20 with one whose protruding length L from the tip surface 21a to the workpiece pressing surface 24 matches the width of the workpiece 4, the hydraulic cylinder 2
0 can securely clamp the workpiece 4 via the protection plate 34.

In the above embodiment, the elastic material 26 for holding the clamp tool 22 in the clamp tool support hole 27 is attached to the spherical support part 25 of the clamp tool 22. Alternatively, the inner peripheral surface of the support hole 27 may be coated with an elastic paint.

<Effects of this invention> According to the present invention, the following effects are achieved.

(b) The clamping tool is supported in the clamping tool support hole by the friction of the elastic material, and compared to the conventional clamping tool shown in Figure 6, which is fixed with a screw, the screw loosens and the tip of the screw becomes loose. The durability of the work fixing device is improved without damaging the work or the protective plate or damaging the screws.

(b) Also, since the spherical support part of the clamp tool is supported only by the friction of the elastic material in the clamp tool support hole of the piston rod, even if the width of the workpiece changes beyond the stroke of the cylinder, It is only necessary to pull out the clamping tool against the friction of the elastic material and replace it, and there is no need to move the workpiece press frame. This allows work to be replaced easily and quickly, greatly improving work efficiency.

(c) In addition, when pressing and fixing a workpiece through a protection plate, if you remove the clamping tool in the part where the workpiece is not installed from the tip of the piston rod, the piston rod will not act on the protection plate and the protection plate will This eliminates the problem of being pressed and bent.

[Brief explanation of drawings]

Figures 1 to 5 show an embodiment of the present invention, Figure 1 is a side view of the machine tool and turntable, and Figures 2 to 4 are a plan view, front view, and side view of the workpiece fixing device, respectively. 5 are longitudinal sectional side views of the clamp device, and FIGS. 6A and 6B are views corresponding to FIGS. 2 and 5 of the conventional example. 7... Base plate, 14... Reference receiving frame, 15... Work placement space, 16... Work pushing frame, 19... Unit work receiving surface, 20... Fluid pressure cylinder (hydraulic cylinder), 21... Piston rod, 21a...2
1 tip end surface, 22...clamping tool, 24...work pressing surface, 25...supporting part, 26...elastic material, 2
7... Clamp tool support hole, 31... Pressure fluid supply path (hydraulic supply path), 32... Hydraulic oil chamber, S...2
Operating stroke of 0, protrusion length of L...24.

Claims (1)

[Scope of utility model registration request] A reference support frame 14 and a workpiece press frame 1 are placed on the upper surface of the base plate 7.
6 and 6 are fixed facing each other with a work placement space 15 open, and each unit work receiving surface 19 is formed at a plurality of locations in the length direction of the surface of the reference receiving frame 14 facing the work pushing frame 16, and each unit Each fluid pressure cylinder 20 corresponding to the workpiece receiving surface 19 is fixed to the workpiece press frame 16, and the piston rod 21 of each fluid pressure cylinder 20 is fixed to the workpiece press frame 16.
The clamping tool 22 provided at the end of the unit is opposed to each unit workpiece receiving surface 19, and the hydraulic oil chamber 32 of each hydraulic cylinder 20 is connected to the common pressure fluid supply path 31, and from the pressure fluid supply path 31, each In a workpiece fixing device for a machine tool configured to be able to press and drive each piston rod 21 toward the reference receiving frame 14 by supplying pressure fluid to the hydraulic oil chamber 32, the proximal end of the clamping tool 22 is connected to a convex spherical support portion 25. In addition to forming
A clamp support hole 27 is formed at the tip of the piston rod 21, and the support portion 2 is formed in the clamp support hole 27.
The working stroke of the cylinder 20 is defined as the length L in which the workpiece pressing surface 24 formed at the tip of the clamp tool 22 protrudes from the tip surface 21a of the cylinder rod 21. A workpiece fixing device for machine tools characterized by being longer than S.