JPH0131389Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a work lifting prevention device that is installed in a puller-type fixture that centers an annular work coaxially with an arbor.

<Prior art> The so-called puller-type fixture, which centers an annular workpiece coaxially with the arbor, is used to fix an annular workpiece to a worktable during gear cutting work using a hobbing machine, etc., and is available in a wide variety of sizes. It is often used when heavy cutting is required for shaped workpieces.

The conventional puller type fitting is shown in Fig. 2.
A mounting base 2 on which an annular workpiece 1 is placed is attached via bolts 6 to an annular base 5 that is integrally fixed on a worktable 3 with bolts 4, and a mounting base 2 that penetrates the workpiece 1. Arbor guide 7
An arbor 7 whose portion a fits into the inner periphery of the workpiece 1 and whose lower end portion can fit into the base 5 is held movably up and down by a support arm 8 installed above the base 5 so as to be movable up and down. This arbor 7 has work 1
A clamp shaft 10 into which the lower end of the arbor 7 is removably inserted is connected to a hydraulic cylinder (not shown) and is attached to the mounting base 2 integrated with the base 5. It is fitted so that it can move up and down.

On the other hand, the puller type fixture with the above configuration has a workpiece 1
A work stopper 11 is provided to prevent the work 1 from rising together with the arbor 7 when the arbor 7 rises during unclamping. Work stopper 11
is placed above work 1 so as to straddle the arbor,
It is fixed to a column (not shown). 12 in the figure
is a work guide.

When fixing the workpiece 1 to a puller-type fixture provided with the workpiece stopper 11 having the above configuration, first the arbor 7 is lowered together with the support arm 8, and the arbor 7 is passed through the workpiece 1 and fitted into the mounting base 2. When the arbor 7 is fitted into the mounting base 2, the lower end of the arbor 7 is clamped by the clamp shaft 10, the clamp shaft 10 is lowered, the arbor 7 is further lowered, and the workpiece 1 is pressed against the mounting base 2 by the holding member 9, and the workpiece 1 is fixed. be done. At this time, the arbor guide 7a of the arbor 7 is fitted into the inner periphery of the work 1.

Conversely, when the workpiece 1 is to be unfixed, the clamp shaft 10 is first raised to raise the arbor 7, the pressure by the presser member 9 is released, and the support arm 8 is lifted.
At the same time, the arbor 7 is raised. At this time, the workpiece 1 is fitted into the arbor guide 7a, so it rises together with the arbor 7, but when it comes into contact with the workpiece stopper 11 and passes through the arbor guide 7a, it falls onto the mounting base 2.

<Problems to be solved by the invention> When the workpiece 1 is not fixed, in order to fix the workpiece 1 at the correct position on the mounting table 2, the workpiece stopper 11 must be installed with as much clearance as possible from the top surface of the workpiece 1. need to be reduced. By the way, with the recent use of NC machines, the attachment and detachment of the workpiece 1 has come to be automatically performed by an attachment/detachment device. Therefore, when using a detachable device, the fixed stopper 11 is used to prevent interference between the detachable device and the fixture.
must be mounted away from the top surface of the workpiece 1, and no workpiece guide 12 or the like is provided. As a result, when work 1 is unfixed, work 1
cannot be fixed in the correct position on the mounting base 2, or
The workpiece 1 may fall from the mounting base 2, making the loading operation by the attachment/detachment device uncertain.

This invention was developed to solve the above-mentioned problems, and it is possible to reliably prevent the workpiece from lifting up when unclamping the workpiece, to place the workpiece in the correct position on the mounting table, and to use the attachment/detachment device. An object of the present invention is to provide a device for preventing lifting of a workpiece in a puller-type fixture that does not interfere with the lifting of a workpiece.

<Means for Solving the Problems> The structure of the present invention to achieve the above object includes a workpiece mounting table that is mounted on a base and on which an annular workpiece is placed, and a workpiece mounting table that is mounted on the base so as to be movable up and down. a support arm holding an arbor capable of penetrating the workpiece placed on the workpiece mounting base and fitting into the base; A work lifting prevention device equipped on a puller-type fixture, which includes a holding member that presses against a mounting base, and a clamp shaft that is vertically movably provided on the base and into which the lower end of the arbor can be fitted. ,
a stopper having one end positioned on the upper surface of the workpiece placed on the workpiece fixture and capable of rotating in a horizontal plane about a rotating shaft erected on the base; The stopper retracting means rotates the stopper in conjunction with the upward movement of the support arm to retract the stopper to the outside in the radial direction of the work when the lower end of the support arm is removed from the work.

<Function> When the workpiece is unclamped, the support arm rises. When the arbor rises, one end of the stopper is positioned on the upper surface of the workpiece, thereby preventing the workpiece from lifting as the arbor rises. Then, when the support arm further rises and the lower end of the arbor comes off the workpiece, the stopper rotates in conjunction with the rise of the support arm, and the stopper is retracted to the outside in the radial direction of the workpiece. By retracting the stopper in conjunction with the rise of the support arm, lifting of the workpiece can be reliably prevented without interference with the stopper even when the attachment/detachment device is used.

<Example> Fig. 1 schematically shows the structure of a puller-type fixture equipped with a work lifting prevention device according to an embodiment of the present invention. A plane is shown. Since the puller-type fixture is the same as the conventional one, the same reference numerals as those used in FIG. 2 are used, and redundant explanation will be omitted.

A main body 21 of the work lifting prevention device is fixed to the column 20 to which the work table 3 is fixed, and a rotating shaft 22 is supported on the main body 21 so as to be parallel to the arbor 7 and rotatable around the central axis. A groove 23 is provided in the rotating shaft 22 along the axial direction from the lower end upward, and this groove 23 extends upward from the lower end to the fitting length of the arbor 7 into the mounting base 2 and the workpiece 1 when the workpiece is clamped. The corresponding length is a straight line portion 23a, and the upper portion of this straight portion 23a is a left-handed twisted portion 23b. On the other hand, a plate 24 is bolted to the support arm 8, and a pin 25 that fits into the groove 23 is connected to the lower end of the plate 24.

In other words, when the support arm 8 rises, the pin 25 first engages with the straight part 23a of the groove 23 and rises.
When the arbor 7 continues to rise and the lower end of the arbor 7 comes off from the mounting base 2 and the workpiece 1, the pin 25 fits into the twisted portion 23b of the groove 23, and the rotating shaft 22 rotates to the right.

A stopper 26 is attached to the upper end of the rotary shaft 22 so that when the workpiece 1 is clamped and the support arm 8 is lowered, the tip is positioned on the upper surface of the workpiece 1 without leaving a gap so as to straddle the arbor 7. There is. In other words, the stopper 10 retracting means is
2, a plate 24, a pin 25, and a groove 23.

Next, the operation of the work lifting prevention device having the above structure when unclamping a work will be explained.

When the workpiece is fixed, the tip of the stopper 26 is positioned on the upper surface of the workpiece 1 without any gap. First, the clamp shaft 10 is raised to raise the arbor 7 to release the pressing member 9 against the workpiece 1, and the clamp between the clamp shaft 10 and the arbor 7 is released. Next, the arbor 7 is raised together with the support arm 8. At this time, the plate 24 also rises together with the support arm 8, and the pin 25 coupled to the plate 24 rises along the groove 23 of the rotating shaft 22. When the support arm 8 is raised, the pin 25 is inserted into the straight part 23 of the groove 23 while the arbor 7 is fitted into the mounting base 2.
a and rises, the rotary shaft 22 does not rotate and the stopper 26 remains positioned on the upper surface of the workpiece 1 without leaving a gap, so the workpiece 1
6 and will not be lifted up together with the arbor 7, and the workpiece 1 will not be lifted off the mounting base 2.
When the support arm 8 is raised, when the lower end of the arbor 7 comes off the workpiece 1, the pin 25 engages with the twisted part 23b of the groove 23 and rises, the rotating shaft 22 rotates to the right, and the stopper 26 moves the workpiece 1 off. Retract radially outward. Therefore, when the workpiece 1 is brought into an unfixed state, the workpiece 1 is not lifted up together with the arbor 7, but is fixed at a regular position on the mounting base 2. Moreover, when the workpiece 1 is not fixed, the stopper 26
Since the stopper 26 is retracted to the outside in the radial direction of the workpiece 1, the stopper 26 does not interfere with the attachment/detachment device of the workpiece 1, etc.

In the above embodiment, the stopper 26 is retracted by fitting the pin 25 into the groove 23 of the rotating shaft 22,
5 is raised together with the support arm 8, but the structure is not limited to the above embodiment as long as the stopper 26 can be retracted in conjunction with the rise of the support arm 8.

<Effect of the invention> The device for preventing lifting of the workpiece in the puller-type fixture of the present invention is such that when the workpiece is unclamped, the stopper is positioned on the upper surface of the workpiece without leaving a gap until the arbor is removed from the workpiece due to the rise of the support arm. Therefore, it is possible to reliably prevent the workpiece from lifting up and to fix the workpiece at the proper position on the mounting base. Further, when the arbor is removed from the workpiece due to the rise of the support arm, the stopper is retracted to the outside in the radial direction of the workpiece in conjunction with the rise of the support arm, so that there is no interference with the attaching/detaching device or the like. As a result, the workload loading operation by the attachment/detachment device, etc. becomes reliable, and the shape of the clamp claw of the attachment/detachment device, etc. can be freely designed.

[Brief explanation of the drawing]

Fig. 1 shows the schematic structure of a puller-type fixture equipped with a work lifting prevention device according to an embodiment of the present invention, Fig. 1a is a side view thereof, Fig. 1b is a plan view thereof, and Fig. 1b is a plan view thereof. The figures schematically show the structure of a puller-type fixture equipped with a conventional fixed work lifting prevention device, with FIG. 2a being a side view thereof and FIG. 2b being a plan view thereof. In the drawings, 2 is a mounting base, 5 is a base, 7 is an arbor, 8 is a support arm, 9 is a holding member, 10 is a clamp shaft, 22 is a rotating shaft, 23 is a groove, 23a is a direct part, 23b is a twisted part, 24 is a plate, 2
5 is a pin.

Claims (1)

[Scope of utility model registration request] a work mount mounted on a base and on which an annular work is placed; and a work mount that is movable up and down on the base and can be inserted into the base by penetrating the work placed on the work mount. a support arm that holds an arbor; a presser member that is connected to the arbor and presses the workpiece to the workpiece mounting base as the arbor descends; A work lifting prevention device is installed on a puller-type fixture that is equipped with a clamp shaft that can be fitted, the device having one end positioned on the top surface of the work placed on the work fixture, and a device that prevents lifting of the workpiece, the device being equipped with a puller-type fixture that can be fitted with a clamp shaft. a stopper capable of rotating in a horizontal plane around an upright rotating shaft; 1. A work lifting prevention device in a puller type fixture, comprising a stopper retracting means for rotating the stopper and retracting the stopper radially outward of the work.