JPH0448906Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a clamping device for ring-shaped workpieces, and more specifically, it is a device for reliably centering and positioning workpieces and clamping them with a simple configuration during gear cutting. This invention relates to a device for clamping a ring-shaped workpiece.

[Prior art]

A clamping device used when performing gear cutting on a ring-shaped workpiece usually includes a clamping means for clamping and fixing the workpiece on a clamp table, and a centering mechanism inserted into a center hole of the workpiece. As a centering mechanism, for example, the one described in Japanese Utility Model Application Publication No. 61-35719 uses a plurality of ball-shaped rocket pieces that are held in a hole provided in the shaft wall of a centering shaft having a hollow portion so as to be freely retractable. is pressed against the inner wall of the center hole of the workpiece by a taper plunger that is forcibly driven within its centering shaft. and,
After centering and positioning, the workpiece is clamped by a clamping means that is provided concentrically with the centering shaft and driven in the axial direction, separate from the centering mechanism.

[Problem that the invention attempts to solve]

As mentioned above, when using an expanding means that presses a ball-shaped locate piece against the inner wall of the center hole of a workpiece using a taper plunger, high-pressure oil or high pressure is used to drive the expanding means and the clamping means. There was a problem in that the structure became complicated due to the provision of a complicated fluid introduction passage for introducing air and a lid to prevent the locate piece pressurized outward from jumping out. In addition, since the locate piece is ball-shaped, if it is strongly pressed by the taper plunger when clamping the workpiece, it will bite into the inner wall of the center hole of the workpiece, and even if the clamp is released and the plunger is returned, the locate piece will not hold the workpiece. There were times when I couldn't get away from him. For such cases, a separate means for removing the locate piece attached to the inner wall of the center hole has sometimes been required. The present invention has been devised in consideration of these circumstances, and is capable of reliably centering and positioning and clamping a workpiece with a simple configuration, and in which an expanding means for centering and positioning is attached to the workpiece after the clamp is released. It is an object of the present invention to provide a clamping device for a ring-shaped workpiece, which allows a processed workpiece to be smoothly carried out without such a problem.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has an expanding means that is inserted into the center hole of a ring-shaped workpiece placed on a workpiece pedestal, expanded, and attached to the inner wall of the center hole. In a clamping device that performs centering and positioning and clamping, a rod is attached downward to a press head that can be driven up and down.
A tapered member having a tapered outer peripheral surface is fitted and fixed, and both tapered members having two different upper and lower tapered surfaces are fitted below the tapered member in the rod so as to be movable by a predetermined amount along the rod. and has two tapered inner circumferential surfaces circumscribing two different upper and lower tapered surfaces of the two tapered members, and expands when the two tapered members are brought close to each other. Means is interposed between the two tapered members, and the workpiece receiving portion is provided with a tapered receiving portion into which the lower tapered surfaces of both the tapered members are slidably fitted.

[Effect]

As the pressing head descends, the lower tapered surfaces of both tapered members, which are fitted and urged downwardly to the lower side of the rod, slide and fit into the tapered receiver provided on the workpiece pedestal. Both tapered members are centered. After that, the pressing head further descends, and the tapered member that is fitted and fixed to the rod approaches both tapered members, and the two tapered inner peripheries that circumscribe the two different upper and lower tapered surfaces of these two tapered members The expanding means having a surface is expanded and brought into contact with the inner wall of the center hole of the workpiece, and the workpiece is centered and positioned. At this time, the workpiece is pressed and clamped from above onto the workpiece pedestal by the downwardly tapered member via the expanding means.

[Effect of idea]

The device for clamping a ring-shaped workpiece of the present invention has a downwardly tapered member having a downwardly tapered outer circumferential surface fitted and fixed onto a rod that is attached downward to a press head that can be driven vertically. Both tapered members having two different upper and lower tapered surfaces are fitted below the tapered member so as to be movable by a predetermined amount along the rod, and are urged downward. An expanding means that has two circumscribed tapered inner peripheral surfaces and expands when the two tapered members are brought close is interposed between the two tapered members, and the lower side of both of the tapered members Since the workpiece pedestal is equipped with a tapered receiving part into which the tapered surfaces of Processed workpieces can be carried out smoothly without sticking to the surface.

〔Example〕

The present invention will be explained in detail below based on examples.

The ring-shaped workpiece clamping device shown in this example is
When gear-cutting a workpiece gear with a hole installed in an automobile transmission, etc., the workpiece gear can be centered, positioned and clamped at the same time, and is constructed as follows.

As shown in FIG. 1, the upper end of a rod 3 is fixedly attached to a press head 2 that can be driven vertically with respect to a workpiece pedestal 1.
A downwardly tapered member 5 having a downwardly tapered outer peripheral surface 4 is fitted and fixed. Both tapered members 8 having two different upper and lower tapered surfaces 6 and 7 are fitted below the tapered member 5 in the rod 3 with a slight gap so as to be movable by a predetermined distance along the rod 3. It is biased downward. These two tapered members 5 and 8 have two tapered inner circumferential surfaces 9 and 10 that circumscribe the two different upper and lower tapered outer circumferential surfaces 4 and 6, and when the two tapered members 5 and 8 are brought close together, they expand. Expansion means 11 to open
is interposed between the two tapered members 5 and 8. The workpiece pedestal 1 is provided with a tapered receiving portion 12 into which the lower tapered outer circumferential surfaces 7 of both tapered members 8 fit. A pulling means 13 is provided below the workpiece pedestal 1 to grasp the tip of the rod 3 that penetrates the workpiece pedestal 1 and projects downward, and to pull it down.

The workpiece pedestal 1 is mounted and fixed by bolts 17 on a base 16 that is rotatably provided on a processing station 15 where a gear cutter 14 is disposed. The press head 2 is pressed against the ring-shaped workpiece 18 placed on the workpiece pedestal 1.
is driven vertically through the center hole 18a of the workpiece 18 by a drive source (not shown), and the upper end is attached to the pressing head 2 by a nut 19.
As shown in the figure, the rod 3 which is fastened and fixed by the rod 3 is inserted into the rod hole 20 which is drilled concentrically through the tapered recess 12 which is a tapered receiving part provided on the workpiece pedestal 1, and its tip The portion 21 is adapted to protrude downward. A flange-shaped portion 22 is formed on the tip 21 of the rod 3, and the flange is connected to a cylinder device 23 that is disposed below the workpiece pedestal 1 and drives up and down, and is opened and closed by claw members 24 and 25. The shaped portion 22 is grasped and held from both sides, and the rod 3 is pulled downward. A claw member 24 for this flange-shaped portion 22,
In order to release the gripping state of the rod 25, a thin rod-shaped contact 26 is suspended from the tip 21 of the rod 3 in the axial direction, and both claw members 24 and 25 are raised by the cylinder device 23. When the claw member 24 on the near side comes into contact with the contact 26 and opens outward,
The other claw member 25, which is interlocked with this, is also opened outward at the same time. Note that below the workpiece pedestal 1 are claw members 24, 2 that are lowered in an open state by the cylinder device 23.
In order to engage the claw member 25 with the collar portion 22, a biasing means 27 is provided which presses the claw member 25 inward from the side. In the figure, 27a is a push rod, and 28 is a spring.

A tapered member 5 that is fitted and fixed to the upper part of the rod 3 is disposed at the lower part of the pressing head 2 via an intervening member 29, and its tapered outer peripheral surface 4 is formed concentrically with the axis of the rod 3. ing. A tapered outer peripheral surface 6 is formed concentrically with the axis of the rod 3 on the upper half of both tapered members 8 fitted below the tapered member 5, and a tapered outer peripheral surface 6 is formed on the lower half thereof. Similarly, a tapered outer peripheral surface 7 is formed. A support pin 31 is fixedly fixed to the middle part of both tapered members 8 by passing through it in the lateral direction.
2, and is fitted in the container so as to be movable up and down. This support pin 31 is fitted into a through hole 33 formed in the axial direction in the rod 3 so as to be movable up and down, and is fixed to pass through the lower end of a push rod 35 which is urged by a spring 34 from above. Therefore, in the free state,
The support pin 31 contacts the lower end of the elongated hole 32, and both tapered members 8 are urged downward by the urging force of the spring 34.

The expanding means 11 interposed between the tapered member 5 and both tapered members 8 is a collet made of a ring-shaped elastic member having axial slits that open vertically alternately. The half part is an upwardly tapered inner circumferential surface 9 that circumscribes the downwardly tapered outer circumferential surface 7 of the downwardly tapered taper member 5 , and the lower half is circumscribed by the upwardly tapered outer circumferential surface 6 of both tapered members 8 . The tapered inner circumferential surface 10 is tapered downward.

The operation of the ring-shaped workpiece clamping device configured as described above will be explained.

(1) Although not shown, the workpiece 18 is placed on the workpiece pedestal 1 placed on the processing station 15 by a conveyance means such as a turntable.
At this time, the pressing head 2 is placed in an upper standby position, and the tip 21 of the rod 3 is located above the workpiece 18.

(2) The press head 2 descends, the rod 3 passes through the rod hole 20 of the workpiece pedestal 1, and its tip 2
1 protrudes downward, and both tapered members 8
The downwardly tapered outer circumferential surface 7 is slidably fitted into the tapered recess 12 of the workpiece pedestal 1, and centering of both the tapered members 8 is performed. Incidentally, since both tapered members 8 are fitted to the rod 3 with a slight gap, they retreat to a position balanced with the biasing force of the spring 34, and the tapered outer peripheral surface 7 becomes tapered. By being fitted into the recess, it is accurately centered with respect to the workpiece pedestal 1.

(3) When the double claw members 24 and 25, which are located above the illustrated position and are open on both sides, are lowered by the cylinder device 23, the claws are attached to the tip of the push rod 27a that is biased inward. The outer surface of the member 25 comes into sliding contact, both claw members 24 and 25 are gradually closed, and the flange-like portion 22 of the rod 3 is brought into contact with both claw members 24 and 2.
5, it is grasped and held from both sides.

(4) By the cylinder device 23, both claw members 24, 2
5 further lowers the rod 3, and both tapered members 8 rise relative to the rod 3 while resisting the biasing force of the spring 34, while the downwardly tapered taper fixed to the lower part of the pressing head 2 Member 5 is lowered and two tapered members 5 and 8
become closer to each other. Then, the tapered outer circumferential surface 4 of the downwardly tapered member 5 becomes the upwardly tapered inner circumferential surface 9 of the collect 11, and the upwardly tapered outer circumferential surface 6 of both tapered members 8 becomes the downwardly tapered inner circumferential surface of the collet 11. The collet 11 is expanded while slidingly contacting the collet 10, and as shown in the figure, the outer peripheral surface of the collet 11 is brought into contact with the inner wall of the center hole 18a of the workpiece 18, and the workpiece 18 is centered and positioned. At this time, since the tapered member 5 is strongly pulled downward by the cylinder device 23, the workpiece 18 is clamped onto the workpiece pedestal 1 via the collet 11. Even when the rod 3 is further lowered, both tapered members 8 are further urged downwardly by the spring 34, and the centered state is maintained. At that position, the gear cutter 14 is operated to perform gear cutting.

(5) When the gear cutting process is completed, both claw members 24 and 25 are raised by the cylinder device 23. Then, the contact 26 protruding from the tip 21 of the rod 3 slides into contact with the inner surface of the claw member 24 on the near side and pushes it down, opening both claw members 24 and 25, and gripping the rod 3. is canceled.
Note that the push rod 27a that is in contact with the outer surface of the claw member 25 retreats while resisting the biasing force of the spring 28.

(6) When the pressing head 2 is moved upward to raise the rod 3, both taper members 8 are tapered downward and separated from the taper member 5 due to the biasing force of the spring 34, and these two taper members 5 and 8 are attached to the collet 11. It separates from both inner circumferential surfaces 9 and 10 of. Then,
The collet 11 is reduced in diameter and removed from the inner wall of the center hole 18a of the workpiece 18, leaving the workpiece 18 on the workpiece pedestal 1 and returned together with the rod 3 to the standby position. The processed workpiece 18 is transferred to a station for the next process by a carry-out means.

As described above, according to the clamping device for a ring-shaped workpiece shown in this example, the centering and positioning of the workpiece 18 and the clamping operation can be performed simultaneously with a simple configuration, and when the pressing head 2 is moved upward during unclamping, the collection 11 Since the workpiece 18 is separated from the center hole 18a of the workpiece 18, the processed workpiece 18 can be quickly transferred to the next process station.

FIG. 2 shows a different embodiment in which both tapered members 4
1, the lower tapered surface is a downwardly tapered inner circumferential surface 42, and the tapered receiving portion of the workpiece pedestal 43 is an upwardly tapered convex portion 44.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of a ring-shaped workpiece clamping device of the present invention, and FIG. 2 is a sectional view of both tapered members and a tapered receiving portion in a different embodiment. 1...Work pedestal, 2...Press head, 3...
Rod, 4... Tapered outer circumferential surface tapered downward, 5... Tapered member tapered downward, 6... Tapered surface (tapered outer circumferential surface tapered upward), 7... Tapered surface (tapered outer circumferential surface tapered downward), 8... ...both tapered members, 9... upper tapered inner circumferential surface, 10... lower tapered inner circumferential surface, 11
. . . Expansion means (collection), 12 . . . Taper receiving portion (tapered recess), 18 .

Claims (1)

[Scope of Claim for Utility Model Registration] Centering and positioning of the workpiece by means of an expanding means that is inserted into the center hole of a ring-shaped workpiece placed on a workpiece pedestal, expanded and attached to the inner wall of the center hole. In a clamping device for clamping, a downwardly tapered member having a downwardly tapered outer circumferential surface is fitted and fixed to a rod that is attached downward to a pressing head that can be driven vertically, and the downwardly tapered member in the rod is fitted and fixed. Both tapered members having two different upper and lower tapered surfaces on the lower side are fitted so as to be movable by a predetermined amount along the rod and are biased downward. An expanding means having two tapered inner peripheral surfaces and expanding when the two tapered members are brought close is interposed between the two tapered members, and a lower tapered outer periphery of both the tapered members. A clamping device for a ring-shaped workpiece, characterized in that the workpiece pedestal is provided with a tapered receiving part whose surfaces are slidably fitted.