JP5412944B2 - Rotating body clamping device - Google Patents

Description

  The present invention relates to a rotating body clamping device that clamps a rotating body against a base using a clamping sleeve.

  In a rotary table or the like of a machine tool, a rotary shaft portion of the rotary table or the like is supported by a base so that it can be rotated and indexed via a bearing, and the rotary table is supported at a predetermined angular position with respect to the base when processing a workpiece. It is designed to clamp. As one means for clamping the rotary table, there is one using a clamping sleeve (elastic ring 5) as described in Patent Document 1. The clamping sleeve is made of, for example, elastically deformable high elasticity steel and has a crank-like cross-sectional shape in which a plurality of annular grooves are alternately formed on the inner and outer circumferences. The clamping sleeve is fixed to the base. It is arranged in an annular space formed between the outer peripheral surface of the hollow cylindrical body and the inner peripheral surface of the rotating shaft portion, and is pressed in the axial direction by a piston so that the inner diameter is the same as that of a bellows. The outer diameter of the clamping sleeve is increased and the inner and outer peripheries of the clamping sleeve are brought into close frictional engagement with the outer peripheral surface of the hollow cylindrical body and the outer peripheral surface of the rotary shaft, and the rotary table is used as a base. It clamps firmly.

JP 11-77490 A

  However, in the one described in Patent Document 1, there is no particular problem when clamping the rotary table to the base by pressing the clamping sleeve in the axial direction with the piston. When unclamping, even if the piston is retracted in a direction away from the clamping sleeve, the clamping is firmly frictionally engaged between the rotary shaft portion of the rotary table and the inner and outer peripheral surfaces of the hollow cylindrical body of the base. There is a risk that the sleeve will not return reliably due to its elastic return force.

  In addition, the clamping sleeve is only disposed between the inner peripheral surface of the rotary shaft portion of the rotary table and the outer peripheral surface of the hollow cylindrical body fixed to the base, so that when the rotary table is unclamped The radial position of the clamping sleeve is not fixed, and it comes into contact with the inner peripheral surface of the rotating shaft and the outer peripheral surface of the hollow cylindrical body. For this reason, such as an ultra-precision processing machine that requires high-precision processing. In some products, there is a risk of inaccuracy due to sliding resistance or heat generation, which has been a bottleneck in adoption.

  The present invention has been made to solve the above-described conventional problems, and provides a clamping device for a rotating body that can surely return the clamping sleeve elastically when the piston moves backward when the rotating body is unclamped. It is intended.

The invention according to claim 1 is characterized in that it is formed on the base, the rotating body supported by the base so as to be capable of rotational indexing, the outer peripheral surface formed on one of the base and the rotating body, and the other. Clamping that is disposed in an annular space formed between the inner peripheral surface and the piston and is compressed by being axially pressed by a piston and frictionally engaged with the inner peripheral surface of the base and the rotating body and a sleeve, the rotating body clamping device for clamping the rotary member relative to the base by the clamping sleeve, one end of the clamping sleeve, the piston and integrally set only, the movement of the piston rotating body, characterized in that the clamping sleeve, forcibly pulling unclamped by friction against for cooperation with the elastic return direction of the base and the inner peripheral surface of the rotating body by Clamping device.
That is.

  A feature of the invention according to claim 2 is that, in claim 1, the other end of the clamping sleeve is integrally connected to the base side.

  The invention according to claim 3 is characterized in that, in claim 1 or 2, one end of the clamping sleeve is integrally connected to the piston by a bolt, and the other end of the clamping sleeve is connected to the base. That is, it is integrally connected to the side by a bolt.

Feature of the invention according to claim 4, in請 Motomeko 3, the other end of the clamping sleeve, while clamping the rotary member relative to said base by said clamping sleeve, said group by said bolt That is, it can be integrally connected to the base side.

According to the first aspect of the present invention, one end of the clamping sleeve disposed in the annular space formed between the outer peripheral surface formed on one of the base and the rotating body and the inner peripheral surface formed on the other. a piston integral with setting only, the clamping sleeve by the movement of the piston, forcing tensile un clamp the elastic return direction against the frictional engagement cooperation between the inner and outer peripheral surfaces of the base and rotating member As a result, when the rotating body is unclamped, one end of the clamping sleeve can be forcibly pulled by the piston, whereby the clamping sleeve can be frictioned between the base and the inner and outer peripheral surfaces of the rotating body. It is possible to reliably unclamp against the engaging action.

  According to the invention of claim 2, since the other end of the clamping sleeve is integrally connected to the base side, a clearance is secured between the clamping sleeve, the base and the inner and outer peripheral surfaces of the rotating body. This makes it possible to prevent the clamping sleeve from coming into contact with the base and the inner and outer peripheral surfaces of the rotating body when the rotating body is unclamped.

  According to the invention of claim 3, one end of the clamping sleeve is integrally connected to the piston by a bolt, and the other end of the clamping sleeve is integrally connected to the base side by a bolt. The produced clamping sleeve and piston can be easily connected together.

  According to the invention of claim 4, the other end of the clamping sleeve is configured to be integrally connected to the base side by the bolt in a state where the rotating body is clamped to the base by the clamping sleeve. Therefore, the clamping sleeve can be securely held at the radial center position of the annular space when the rotating body is unclamped. As a result, the clamping sleeve can be prevented from contacting the base and the inner and outer peripheral surfaces of the rotating body, and frictional resistance and heat generation can be suppressed.

It is sectional drawing which shows the clamp apparatus of the rotary body which concerns on embodiment of this invention. It is an expanded sectional view which expands and shows the principal part of FIG. It is a figure which shows the modification of FIG.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a specific example in which the rotating body clamping device of the present invention is applied to a rotating table clamping device.

  In FIG. 1, reference numeral 10 denotes a base, and a rotary table 12 as a rotating body is supported on the base 10 via a bearing 11 so as to be rotatable around a vertical axis. A hollow cylindrical body 13 is fixed to the base 10 on the central axis O <b> 1 of the turntable 12 with bolts. A flange portion 14 is formed at the upper portion of the hollow cylindrical body 13, and a central shaft portion 15 having a predetermined outer diameter is formed at the lower portion of the flange portion 14.

  The rotary table 12 includes a hollow disk-shaped table portion 17 on which a workpiece is placed, and a stepped cylindrical portion 18 that is coaxially disposed on the lower surface of the table portion 17 and is integrally fixed by bolts. It is made up of. The stepped cylindrical portion 18 is supported on the base 10 by a cross roller bearing 19 constituting the bearing 11 so as to be rotatable around a vertical axis. The stepped cylindrical portion 18 is formed with a hollow rotating shaft portion 20 that is loosely fitted to the outer periphery of the flange portion 14 of the hollow cylindrical body 13 of the base 10. The rotating shaft portion 20 is the central axis of the hollow cylindrical body 13. As shown in FIG. 2, an annular space portion 21 is formed between the inner peripheral surface 20 a of the rotary shaft portion 20 and the outer peripheral surface 15 a of the central shaft portion 15, as shown in FIG. 2. Forming.

  A worm wheel 23 is integrally fixed to the outer periphery of the rotary shaft portion 20 with a bolt, and a worm shaft 24 meshing with the worm wheel 23 is rotatably supported by the base 10. A servo motor (not shown) is connected to the worm shaft 24, and the rotary table 12 can be indexed to a predetermined angular position by rotating the servo motor based on a rotation command.

  In the annular space 21 formed between the inner peripheral surface 20a of the rotary shaft portion 20 and the outer peripheral surface 15a of the central shaft portion 15, as shown in detail in FIG. And a piston 31 that compresses and pulls the clamping sleeve 30 in the axial direction is disposed on the upper portion of the clamping sleeve 30. Oil chambers 33 and 34 are formed on both sides of the piston portion of the piston 31, and oil passages 35 and 36 formed in the hollow cylindrical body 13 are connected to the oil chambers 33 and 34, respectively. Pressure oil is supplied to the oil passages 35 and 36 from the pressure oil supply source P through the electromagnetic switching valve 38, and the piston 31 can slide in the vertical direction by the action of the pressure oil. ing. A plurality of oil seals are mounted between the inner periphery of the piston 31 and the outer periphery of the hollow cylindrical body 13 to seal the oil chambers 33 and 34.

  The clamping sleeve 30 is made of, for example, elastically deformable high elasticity steel, and as is well known, a plurality of annular grooves are alternately formed on the inner and outer circumferences to form a crank-shaped cross-sectional shape. When the clamping sleeve 30 is in a free state, its radial dimension (outer diameter—inner diameter) is smaller than the radial dimension of the annular space 21, and the rotary shaft portion 20 of the rotary table 12 is a base. 10 can rotate freely with respect to the central shaft portion 15, but when the clamping sleeve 30 is pressed in the axial direction by the piston 31, the inner diameter of the clamping sleeve 30 is obtained by the same action as the bellows. Is contracted and the outer diameter is enlarged. As a result, the inner periphery of the clamping sleeve 30 is in close frictional engagement with the outer peripheral surface 15a of the central shaft portion 15, and the outer periphery of the clamping sleeve 30 is in close frictional engagement with the inner peripheral surface 20a of the rotating shaft portion 20. Then, the rotating shaft 20 (the rotating table 12) is clamped precisely and firmly on the central shaft 15 (base 10).

  One end of the clamping sleeve 30 is integrally connected to the piston 31 by a bolt 41 as shown in FIG. That is, a screw hole 43 is formed at one end of the clamping sleeve 30, and a bolt 41 that is screwed into the screw hole 43 is inserted through the piston 31 and screwed into the screw hole 43. As described above, since one end of the clamping sleeve 30 is coupled to the piston 31, when the piston 31 is moved upward, the one end of the clamping sleeve 30 resists frictional engagement and is elastically restored. Therefore, the turntable 12 can be unclamped reliably.

  Next, the operation of the rotating body clamping device in the above-described embodiment will be described. When the rotary table 12 is indexed to a predetermined angular position, the electromagnetic switching valve 38 is switched to the state shown in FIG. 2, and pressure oil is supplied from the pressure oil supply source P to the oil chamber 34 via the oil path 36. Then, the oil is discharged from the oil chamber 33 through the oil passage 35 to the reservoir R. As a result, the piston 31 is moved upward, and the other end of the clamping sleeve 30 coupled thereto is pulled upward. As a result, one end of the clamping sleeve 30 is forcibly pulled in the elastic return direction against the frictional engagement action between the outer peripheral surface 15a of the central shaft portion 15 and the inner peripheral surface 20a of the rotary shaft portion 20. As shown in FIG. 2, the rotary shaft 20 (the rotary table 12) is unclamped.

  In this state, a servo motor (not shown) is driven to rotate based on a rotation command from the control device, and the rotary table 12 is rotated around the central axis O1 by a predetermined angle via the worm shaft 24 and the worm wheel 23. The amount of rotation of the turntable 12 is detected by an unillustrated encoder, and the turntable 12 is positioned at a predetermined angular position.

  When the rotary table 12 is positioned at a predetermined angular position, the electromagnetic switching valve 38 is switched, pressure oil is supplied from the pressure oil supply source P to the oil chamber 33 via the oil passage 35, and from the oil chamber 34. Oil is discharged to the reservoir R through the oil passage 36. Thereby, the piston 31 is moved downward, and the clamping sleeve 30 is pressed (compressed). When the clamping sleeve 30 is pressed by the piston 31, the inner diameter of the clamping sleeve 30 is reduced and the outer diameter is enlarged. The clamping sleeve 30 is formed by the outer peripheral surface 15 a of the central shaft portion 15 and the rotating shaft portion 20. The rotary shaft portion 20 (the rotary table 12) is clamped against the central shaft portion 15 (base 10) by being firmly frictionally engaged with the inner peripheral surface 20a.

  As described above, according to the present embodiment, since one end of the clamping sleeve 30 is integrally connected to the piston 31 by the bolt 41, when the piston 31 is moved in a direction away from the clamping sleeve 30, The ping sleeve 30 is forcibly pulled in the elastic return direction against the frictional engagement action, and the unclamping of the rotary table 12 can be reliably performed.

  In addition, after the piston 31 and the clamping sleeve 30 are separately manufactured, the piston 31 and the clamping sleeve 30 can be easily integrally connected by the bolt 41.

  FIG. 3 shows a modification of the present invention. The difference from the above-described embodiment is that the other end of the clamping sleeve 30 is integrally coupled to the base 10 by a bolt 42. Hereinafter, points different from the embodiment will be mainly described. However, the same components are denoted by the same reference numerals, and description thereof will be omitted.

  In FIG. 3, a screw hole 44 is also formed at the other end of the clamping sleeve 30, and a bolt 42 screwed into the screw hole 44 is inserted through the base 10 and screwed into the screw hole 43. At this time, the insertion hole 46 formed in the base 10 through which the bolt 42 is inserted is constituted by a fool hole having an inner diameter larger than the axial diameter of the bolt 42, and the rotary table 12 is clamped by the clamping sleeve 30. The other end of the clamping sleeve 30 is integrally assembled to the base 10 by a bolt 42.

  That is, as an assembly procedure for fixing the other end of the clamping sleeve 30 to the base 10, first, the clamping sleeve 30 is pressed by the piston 31 to clamp the rotary table 12, and the bolt 42 is inserted in this state. The clamping sleeve 30 can be coupled to the base 10 at the center position in the radial direction of the annular space 21 by inserting the hole (bucker hole) 46 and screwing it into the screw hole 44 of the clamping sleeve 30. By such a simple method, in a state where the rotary table 12 is unclamped, the clamping sleeve 30 can be reliably held at the center position in the radial direction of the annular space portion 21, and the clamping sleeve 30 is centered. A situation in which the outer peripheral surface 15a of the shaft portion 15 is contacted or the inner peripheral surface 20a of the rotating shaft portion 20 is contacted can be reliably avoided, and frictional resistance and heat generation can be suppressed.

  According to this modification, the other end of the clamping sleeve 30 can be integrally connected to the base 10 side by the bolt 42 in a state where the rotary table 12 is clamped to the base 10 by the clamping sleeve 30. Thus, one end of the clamping sleeve 30 can be coupled to the base 10 at the radial center position of the annular space 21, and the clamping sleeve 30 can be connected to the annular space 21 when the rotary table 12 is unclamped. Can be held at the center position in the radial direction. Therefore, it is possible to reliably avoid the situation where the clamping sleeve 30 contacts the outer peripheral surface 15a of the central shaft portion 15 or the inner peripheral surface 20a of the rotary shaft portion 20, and suppresses frictional resistance and heat generation. can do.

  In the above-described embodiment, the example in which the present invention is applied to the clamp of the rotary table 12 supported so as to be able to rotate and index on the base 10 has been described. However, the present invention provides a rotary body on a base such as a housing. The present invention can be applied to a wide range of rotating body clamping devices that are supported so as to be capable of rotational indexing.

  Moreover, in above-described embodiment, it is between the outer peripheral surface 15a of the center shaft part 15 provided in the base 10 side, and the inner peripheral surface 20a of the rotating shaft part 20 provided in the rotary body (rotary table) 12 side. Although the example in which the clamping sleeve 30 is disposed has been described, the annular space portion in which the clamping sleeve 30 is disposed is formed by an inner peripheral surface provided on the base 10 side and an outer peripheral surface provided on the rotating body 12 side. Of course, the rotation axis of the rotating body does not have to be a vertical axis as described in the embodiment, and it is of course applicable to those that rotate around a horizontal axis.

  Further, in the above-described embodiment, the example in which the clamping sleeve 30 and the piston 31 are separately manufactured and one end of the clamping sleeve 30 is integrally connected to the piston 31 by the bolt 41 has been described. It is not necessary to be a bolt, and the clamping sleeve 30 may be manufactured integrally with the piston 31.

  Further, in the above-described embodiment, the other end of the clamping sleeve 30 is positioned at the center position in the radial direction of the annular space portion 21 by the bolt 42 that passes through the fool hole (insertion hole 46) formed in the base 10. The example which can be combined integrally was described. However, such a configuration is particularly suitable for a machine tool that requires highly accurate machining, but for the present invention, the other end of the clamping sleeve 30 is coupled to the base 10 side as shown in the modification. That is not necessarily a requirement. That is, simply connecting the other end of the clamping sleeve 30 to the base 10 side without providing a hole is used to connect the clamping sleeve 30 to the outer peripheral surface 15a on the base 10 side and the rotary table 12 side during unclamping. It is possible to ensure a clearance between the peripheral surface 20a.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited to the configurations described in the embodiments, and does not depart from the gist of the present invention described in the claims. It can take various forms.

  The clamping device for a rotating body according to the present invention is suitable for use in a machine tool that clamps a rotating body rotatably supported by a base via a bearing at a predetermined angular position.

DESCRIPTION OF SYMBOLS 10 ... Base, 11 ... Bearing, 12 ... Rotating body (rotary table), 15 ... Center shaft part, 15a ... Outer peripheral surface, 20 ... Rotating shaft part, 20a ... Inner peripheral surface, 30 ... Clamping sleeve, 31 ... Piston 41, 42 ... bolts, 46 ... insertion holes.

Claims (4)

Formed between a base, a rotating body supported by the base so as to be able to rotate and index, an outer peripheral surface formed on one of the base and the rotating body, and an inner peripheral surface formed on the other. A clamping sleeve that is disposed in the annular space and is compressed by being axially pressed by a piston and frictionally engaged with the base and the inner and outer peripheral surfaces of the rotating body. In the rotating body clamping device for clamping the rotating body to the base,
One end of the clamping sleeve is provided integrally with the piston,
The clamping sleeve is unclamped by forcibly pulling the clamping sleeve in the elastic return direction against the frictional engagement action between the base and the inner and outer peripheral surfaces of the rotating body by the movement of the piston.
A rotating body clamping device.   The rotating body clamping device according to claim 1, wherein the other end of the clamping sleeve is integrally connected to the base side.   3. The clamping sleeve according to claim 1, wherein one end of the clamping sleeve is integrally connected to the piston by a bolt, and the other end of the clamping sleeve is integrally connected to the base side by a bolt. A rotating body clamping device. 4. The structure according to claim 3, wherein the other end of the clamping sleeve can be integrally connected to the base side by the bolt while the rotating body is clamped to the base by the clamping sleeve. A clamping device for a rotating body.

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