JP4000560B2 - Work support device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a workpiece support device capable of fixing a support rod supporting a workpiece at an arbitrary height position when machining the workpiece with a machine tool.
[0002]
[Prior art]
The workpiece support device includes a support rod that is movable in the axial direction within the body. A collet is fitted on the outer peripheral surface of the support rod. The outer peripheral surface of the collet is formed with a tapered outer peripheral surface that inclines from one end side in the axial direction toward the other end side. A piston having a taper inner peripheral surface facing the taper outer peripheral surface from the outside is inserted between the collet and the body. The piston is moved by fluid pressure or a spring in the direction of reducing the diameter of the collet or releasing the diameter. When supporting the workpiece, with the collet diameter reduced, the tip of the support rod comes into contact with the workpiece, and in that state the piston is moved to reduce the collet diameter, and the support rod is clamped and fixed by the collet diameter reduction. To do. Examples of such are disclosed in Japanese Utility Model Publication No. 6-7868, Japanese Patent Application Laid-Open No. 9-300154, and Japanese Patent Application Laid-Open No. 10-146733. In these devices, the collet is in contact with the lower wall of the body by an elastic body. When fixing the support rod, first, the collet is pressed against the lower wall of the body by the piston, and then the collet is reduced in diameter. The support rod is clamped and fixed. As a result, the body extends upward due to the elastic deformation of the metal, but the collet remains at the height received by the lower wall, so the support rod is not lifted upward and the workpiece is not moved. Is prevented. Further, in Japanese Patent Laid-Open No. 10-146733, a ball is inserted between a tapered outer peripheral surface and a tapered inner peripheral surface to reduce the taper angle and obtain a large clamping force.
[0003]
Moreover, although it is not a workpiece support device, in the one disclosed in Japanese Patent Laid-Open No. 63-38705, the piston rod of the fluid pressure cylinder is fixed by a lock device. This locking device has an inner cylinder (collet) that penetrates the piston rod and has a tapered outer surface in the cylinder tube of the locking device, and a tapered taper whose outer circumferential surface is parallel to the tapered surface of the inner cylinder outside the inner cylinder. The outer cylinder of the surface is arranged coaxially. Both ends of the inner cylinder are in contact with the rod cover, and a ball is interposed between the inner cylinder and the outer cylinder. The outer cylinder is integrally provided with a piston, and is urged by a spring in the direction of reducing the diameter of the inner cylinder. The locking device reduces the diameter of the inner cylinder by the outer cylinder being urged by the spring and locks the piston rod. When releasing the lock, the piston moves the outer cylinder against the urging force of the spring by the piston. The piston rod is moved by releasing the reduced diameter of the inner cylinder.
[0004]
[Problems to be solved by the invention]
In the workpiece support device described in the above-described conventional technique, when the lower wall of the body is fixed to a fixed member such as a table, the piston that acts on the lower wall of the body via the collet when fixing the support rod Since the pressing force is received by the fixed member, there is almost no displacement of the lower wall, and displacement of the upper end position of the support rod held and fixed to the collet is prevented. However, as in Japanese Patent Application Laid-Open No. 10-146733, in the case where a fixing portion that extends outward from the body and is fixed to the fixed member is provided on the upper wall side of the body, the piston is pushed when the support rod is clamped and fixed. The pressure (clamping force) is not received by the stationary member via the lower wall, and the lower wall is pushed down without being restrained by the stationary member by the elastic deformation of the body. For this reason, the support rod clamped by the collet together with the piston is lowered, so that the workpiece cannot be supported, and there is a problem that the machining accuracy of the workpiece is lowered. Similarly, in Japanese Patent Laid-Open No. 63-38705, when a fixing portion is provided on the upper wall of the lock cylinder and fixed to the fixed member, the lower wall of the body is not fixed, so that a tightening force acts on the collet. When doing so, there is a problem that the body is extended and the piston rod is displaced together with the collet. The problem of the present application is that the collet presses the upper and lower walls of the body when the support rod is clamped and fixed even if the work support device has a fixed portion fixed to the fixed side member on the upper wall side of the body. Another object of the present invention is to provide a work support device in which the collet does not move with the displacement of the body and the support rod does not move in the axial direction.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a support rod is provided in the body so as to be movable in the axial direction, a moving means for moving the support rod in the axial direction, and a support rod provided between the outer peripheral surface of the support rod and the inner surface of the body. A work support device comprising a collet device for holding and fixing a first collimating device and a first taper outer peripheral surface that is fitted on the outer peripheral surface of the support rod and is inclined from the central portion toward one end in the axial direction. A collet formed with a second tapered outer peripheral surface inclined in the opposite direction to the first tapered outer peripheral surface toward the other end side, and one end of the collet formed with a first tapered inner peripheral surface facing the first tapered outer peripheral surface A first piston for reducing the diameter of the portion, a second piston for reducing the diameter of the other end portion of the collet formed with the second tapered inner peripheral surface facing the second tapered outer peripheral surface, Consist of a diameter canceling means for canceling the diameter of the collet by the second piston, both ends of the collet, characterized in that in contact with the inner end surface of the respective body (claim 1). According to this, since the collet is provided with two pistons each moving in the opposite direction, each formed with a tapered outer peripheral surface inclined in the opposite direction and a tapered inner peripheral surface for tightening each tapered inner peripheral surface. When the rod is clamped and fixed, a pressing force acts on the collet in both axial directions, so that the pressing forces of the two pistons cancel each other and the pressing of the collet to one end of the body due to the pressing force of the piston is prevented. Thus, the collet is prevented from moving in the axial direction due to the elastic deformation of the body by the collet when the work support is clamped and fixed. Further, since both end faces of the collet are in contact with the body, the movement of the collet in the axial direction is restricted, and the support rod that supports the workpiece does not move.
[0006]
A large number of steel balls are interposed between the first and second tapered outer peripheral surfaces and the first and second tapered inner peripheral surfaces so as to allow rolling (Claim 2). According to this, the taper angle can be reduced similarly to the conventional one, and a large clamping force can be obtained.
[0007]
Forming a protruding portion protruding in the axial direction at one end portion of said collet, the end surface of the protrusion is equal to or abutting the end face in the body (claim 3). Thus, by contacting the protrusion with the inner end surface of the body, the friction between the collet end surface and the body is smaller than when the entire end surface is in contact, and the diameter of the collet is not hindered.
[0008]
The diameter reduction release means is a diameter reduction release spring interposed between the first piston and the second piston (claim 4 ).
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to FIGS. The body 2 of the work support device 1 includes a circular body 3, a mounting portion 4 formed in a square shape on the upper side of the body that extends outward from the body 3, and a body lower wall that is screwed to the body 3. The cap cover 5 and the rod cover 6 which is screwed to the body portion 3 and serves as the upper body wall are configured. The rod cover 6 is prevented from rotating with respect to the body 2 by a non-rotating screw 7. The mounting portion 4 is fixed to a fixed member 8 such as a machine or a jig base by a plurality of mounting bolts (not shown) using the counterbore 4a. The lower portion of the body 2 is formed with a receiving portion 9 that protrudes to the inside of the body, and the lower end portion of the piston holder 10 is sandwiched between the receiving portion 9 and the cap cover 5.
[0010]
A support rod piston 12 is slidably fitted in the center of the piston holder 10. As shown in FIGS. 1 and 5, a cylinder chamber 11 is formed between the piston holder 10 and the cap cover 5, and a lower portion of the support rod piston 12 faces the cylinder chamber 11. Between the upper end portion of the piston holder 10 and the support rod piston 12, a support rod retracting spring 13 as a retracting means is interposed. A support rod 14 is fitted on the outer periphery of the piston holder 10. The support rod 14 penetrates the rod cover 6 and has a tip projecting outside. The support rod 14 is connected to the piston 12 by a connecting bolt 16, and the protruding amount of the support rod 14 is regulated by the connecting bolt 16. Further, a biasing spring 18, which is a biasing means for constantly biasing the support rod 14 in the protruding direction from the body 2, is interposed between the contact bolt 17 and the connecting bolt 16 that are screwed to the tip of the support rod 14. ing.
[0011]
A collet device 21 is provided between the support rod outer peripheral surface 19 and the body inner surface 20. The collet device 21 includes a collet 22, first and second pistons 23 and 24, and a diameter reducing means 25. As shown in FIG. 3, the collet 22 has a substantially cylindrical shape, and is fitted on the outer peripheral surface 19 of the support rod 14, and the support rod 14 is formed by the inner peripheral surface 26 of the collet 22 and the outer peripheral surface 27 of the piston holder 10. Is guided in the axial direction. The collet 22 is provided with a slit 28 extending in the axial direction, and the diameter can be elastically reduced by the slit 28. Further, the outer peripheral surface 29 of the collet 22 has a first tapered outer peripheral surface 30 that is inclined in a tapered manner from the substantially central portion toward one end side in the axial direction (upward), and toward the other end side in the axial direction (downward). It forms in the 2nd taper outer peripheral surface 31 which inclines to a taper in the reverse direction.
[0012]
Further, the collet 22 is formed with a protruding portion 33 protruding in the axial direction at one end portion, and the end surface 33a of the protruding portion 33 abuts on the inner side surface 34 of the rod cover 6 which is one body inner end surface, and the collet 22 The end surface 35 of the other end portion of the other abuts the upper inner surface 36 of the receiving portion 9 which is the other inner end surface of the body, and movement in the axial direction is restricted. As shown in FIG. 4, the end surface 33a of the projecting portion 33 abuts on the body inner end surface 34, thereby reducing the friction and reducing the collet 22 diameter. The resistance between the collet 22 and the inner end faces 34 and 36 is reduced.
[0013]
An annular first piston 23 and second piston 24 are arranged on the outer peripheral side of the collet 22. The first piston 23 is formed with a first taper inner peripheral surface 37 facing the first taper outer peripheral surface 30, and a plurality of steel balls 38 between the first taper inner peripheral surface 37 and the first taper outer peripheral surface 30. Are interposed in a stacked state in contact with each other in the circumferential direction and the axial direction, and a first cylinder chamber 39 is formed between the rod cover 6 and the cylinder. The second piston 24 is formed with a second taper inner peripheral surface 40 facing the second taper outer peripheral surface 31, and a plurality of steel balls 38 also between the second taper inner peripheral surface 40 and the second taper outer peripheral surface 31. Are disposed so as to be stacked in contact with each other in the circumferential direction and the axial direction, and a second cylinder chamber 41 is formed between the cylinder portion 3 and the body portion 3.
[0014]
The cylinder chamber 11, the first cylinder chamber 39, and the second cylinder chamber 41 communicate with the piping port 43 through the fluid communication path 42. In the spring chamber 44 surrounded by the body inner surface 20, the collet outer peripheral surface 29, and the first and second pistons 23 and 24, the first piston 23 and the second piston 24 are separated from each other in the axial direction. A diameter reduction spring 25 as a diameter reduction release means for biasing the first piston 23 and the second piston 24 is interposed in a direction to release the diameter reduction of the collet 22 by the piston 23 and the second piston 24. . The spring chamber 44 communicates with the air reserve port 46 via an air communication passage 47.
[0015]
The fluid pressure acting surface 48 of the piston 12, the first fluid pressure acting surface 49 of the first piston 23, and the second fluid pressure acting surface 50 of the second piston 24 have a projected area of the fluid pressure acting surface 48. The first fluid pressure acting surface 49 and the second fluid pressure acting surface 50 increase in this order. When pressurized fluid is supplied from the piping port 43, the piston 12, the first piston 23, and the second piston 24 are arranged in this order. It comes to move.
[0016]
Next, operation | movement of the workpiece | work support apparatus 1 is demonstrated. When supporting the workpiece W, pressure oil is supplied to the piping port 43. Then, pressure oil is supplied to the cylinder chamber 11, the first cylinder chamber 39, and the second cylinder chamber 41 via the fluid communication path 42, and first, the piston 12 rises against the support rod retracting spring 13 and is connected. The support rod 14 protrudes through the bolt 16 and the biasing spring 18. When the contact bolt 17 abuts against the workpiece W, the ascent of the support rod 14 stops, but further rises until the piston 12 abuts against the piston holder 10 while pressing and contracting the biasing spring 18. Next, the first piston 23 moves downward while contracting the diameter release spring 25, and presses the first taper outer peripheral surface 30 of the collet 22 via the steel ball 38 to correspond to the first taper outer peripheral surface 30. The diameter of the portion is reduced, and the support rod 14 is clamped and fixed by the inner peripheral surface 26 of the collet 22. Further, the second piston 24 moves upward while contracting the diameter release spring 25 with a delay from the first piston 23, and presses the second taper outer peripheral surface 31 of the collet 22 through the steel ball 38, thereby causing the second taper. The diameter corresponding to the outer peripheral surface 31 is reduced, and the support rod 14 is sandwiched and fixed by the inner peripheral surface 26 of the collet 22. Thereby, the support rod 14 is fixed to the height position which supports the workpiece | work W shown in FIG.
[0017]
Thus, by moving the piston 12, the first piston 23, and the second piston 24 in this order, the downward component force of the pressing force of the first piston 23 and the upward component force of the pressing force of the second piston 24 Is canceled, the axial component of the pressing force of the first and second pistons 23, 24 is prevented from moving in the axial direction of the collet 22, and the collet 22 and the support rod 14 are prevented from being displaced in the axial direction. The Further, the collet 22 works so that the axial components of the pressing force of the first piston 23 and the second piston 24 cancel each other, so that the collet 22 presses one end face of the body 2 as in the prior art. The workpiece support device 1 is attached to the fixed side member 8 by the attachment portion 4 at the top of the body 2 without being moved due to the strain of 2 and preventing the support rod 14 from moving integrally with the collet 22. However, the processing accuracy of the workpiece W is not lowered. Further, even if an external force is applied to the collet 22 in a state where the axial components of the pressing force of the first piston 23 and the second piston 24 are offset, the collet 22 is axially applied to the upper and lower end surfaces 34 and 36 of the body 2. Therefore, the support rod 14 held by the collet 22 does not move.
[0018]
Next, when the machining of the workpiece W is completed, the supply of pressure oil to the cylinder chamber 11, the first cylinder chamber 39, and the second cylinder chamber 41 is stopped, and the first piston 23 is moved upward by the diameter reducing spring 25. The second piston 24 is moved downward in the opposite direction, and the collet 22 is expanded in diameter by its own elastic restoring force. The support rod 14 is released from the clamped and fixed state by the collet 22, the piston 12 is moved downward by the support rod retracting spring 13, and the support rod 14 is drawn into the body 2 together with the piston 12.
[0019]
【The invention's effect】
As described above, according to the present invention, the collet device that is externally fitted and clamped and fixed to the support rod that is movable in the axial direction in the body of the work support device is directed from the central portion toward the upper end. A collet formed with a first taper outer peripheral surface inclined in a tapered manner and a second taper outer peripheral surface inclined in a tapered manner toward the lower end from the central portion; and the first taper outer peripheral surface The first piston for reducing the diameter of the upper end portion of the collet formed with the first tapered inner peripheral surface, and the second for reducing the diameter of the lower end portion of the collet formed with the second tapered inner peripheral surface facing the second tapered outer peripheral surface. Since it is composed of a piston and a diameter reduction means for releasing the diameter reduction of the collet by the first and second pistons, when the support rod is clamped and fixed, the collet of the first piston and the second piston is opposed. Since the vertical direction (axis direction) component of the pressing force is canceled and the collet is prevented from being pressed against the upper end or lower end of the body by the pressing force of the piston, the collet moves as the body is elastically deformed, The support rod clamped and fixed integrally with the collet does not move. Further, since both end faces of the collet are in contact with the body, the movement of the collet in the axial direction is restricted, and the support rod that supports the workpiece does not move. For this reason, it is possible to prevent a reduction in workpiece machining accuracy.
In addition, since many steel balls are interposed between the first taper outer peripheral surface and the first taper inner peripheral surface and between the second taper outer peripheral surface and the second taper inner peripheral surface so as to be able to roll, A large clamping force can be obtained with a small taper angle.
Also, the position of the collet is regulated by abutting both end surfaces against the body, and if the abutment is projected to the body by an axially protruding protrusion formed at one end, the friction between the collet and the body Becomes smaller and the loss of the clamping force is reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a workpiece support device.
FIG. 2 is a view taken along the line II in FIG.
FIG. 3 is a perspective view of a collet.
FIG. 4 is a diagram showing contact between a collet protrusion and an inner surface of a rod cover.
FIG. 5 is a diagram showing a state in which a workpiece is supported.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Work support apparatus 2 Body 14 Support rod 19 Support rod outer peripheral surface 20 Body inner surface 21 Collet apparatus 22 Collet 23 1st piston 24 2nd piston 25 Diameter reduction release spring (diameter reduction release means)
30 1st taper outer peripheral surface 31 2nd taper outer peripheral surface 33 Projection part 33a Projection part end surface 34 Rod cover inner surface (Body inner end surface)
35 Collet end face 36 Inner side of the receiving part (Body inner end face)
37 1st taper inner peripheral surface 38 Steel ball 40 2nd taper inner peripheral surface

Claims (4)

A support rod is provided in the body so as to be movable in the axial direction, and includes a moving means that moves the support rod in the axial direction, and a collet device that is provided between the outer peripheral surface of the support rod and the inner surface of the body and clamps and fixes the support rod. In the workpiece support device, the collet device is fitted on the outer peripheral surface of the support rod, and the first taper outer peripheral surface is inclined from the central portion toward one end side in the axial direction and the first taper is directed toward the other end side in the axial direction. A collet formed with a second tapered outer peripheral surface inclined in a direction opposite to the outer peripheral surface, and a first piston for reducing the diameter of one end portion of the collet formed with the first tapered inner peripheral surface facing the first tapered outer peripheral surface; A second piston for reducing the diameter of the other end portion of the collet formed with the second taper inner peripheral surface facing the second taper outer peripheral surface, and the collet contraction by the first and second pistons. It consists of a diameter canceling means for canceling a workpiece supporting device, characterized in that both end faces of the collet is in contact with the inner end face of each body.   2. The workpiece support device according to claim 1, wherein a large number of steel balls are interposed between the first and second tapered outer peripheral surfaces and the first and second tapered inner peripheral surfaces so as to be able to roll. Forming a protruding portion protruding in the axial direction at one end portion of the collet, the work supporting device according to claim 1, wherein the end face of the protrusion is equal to or abutting the end face in the body. Diameter releasing means, the work supporting device of any one of claims 1-3, characterized in that the diameter release spring interposed between the first piston and the second piston.

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