JPH11123607A - Diaphragm-type chuck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strongly fix a diaphragm-type air chuck body to the main spindle of a machine tool without producing a strain in a diaphragm. SOLUTION: Air from a pneumatic device is supplied or discharged to a cylinder 46 to move a piston 60, thereby deforming the thin part of a diaphragm 48 connecting to the piston 60, whereby a workpiece is chucked by claws or released therefrom. The diaphragm 48 has a cylindrical hole 64 where a cylindrical body 68 is inserted. When a bolt 38 inserted into the cylindrical body 68 is screwed into the threaded hole of the flange of the main spindle of the machine tool, the head 38a of the bolt 38 abuts on the other end of the cylindrical body 68 to pinch a base body 34 by the flange and the end surface 68a of the cylindrical body 68 with the fastening force of the bolt 38, whereby the base body 34 is fixed to the flange. The fastening force does not press the diaphragm 48 in the axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm type air chuck used for a machine tool such as an NC lathe.

[0002]

2. Description of the Related Art A conventional diaphragm type air chuck will be described with reference to FIG. (2) is a disk-shaped base body, and its outer diameter portion has a flange (2) of a main shaft of a machine tool.
A plurality of bolt insertion holes (22a) are formed in accordance with the bolt holes (25) of 4). (4) is an intermediate board body, the outer diameter portion of which is fixed to the outer diameter portion of the base (2) by bolts (not shown). A bolt insertion hole (22b) is formed in the board (4) at the same position as the bolt insertion hole (22a). (18) is a diaphragm provided with a claw mount (16). A stepped bolt insertion hole (22c) is formed in the outer diameter portion of the diaphragm (18) at the same position as the bolt insertion holes (22a) (22b). (6) is a partition body, an outer diameter portion of which is fixed to an outer diameter portion of the diaphragm (18), and an inner diameter portion of which is a cylindrical portion (1) of the diaphragm (18).
8a) is slidably fitted to the outer peripheral surface in a sealed state. A first cylinder chamber (8) is formed between the inner surface of the base (2) and the side surface of the board (4), and the other side surface of the board (4) and the partition body (6) are formed. Between them, a second cylinder chamber (10) is formed. The cylinder chambers (8) and (10) have disc-shaped pistons (12) (1).
4) is slidably fitted in the axial direction, and these pistons (12) and (14) are fixed to the cylindrical portion (18a) of the diaphragm (18) by bolts (20). Align the bolt insertion hole (22a) with the bolt hole (25) of the flange (24) of the main shaft of the machine tool, insert a bolt (26) into the bolt insertion hole (22c), and attach the bolt (26) to the flange (24). ), The air chuck body (28) including the base (2), the disk (4), and the diaphragm (18) is detachably fixed to the main shaft flange (24). Air from a pneumatic device (not shown) is supplied to and discharged from the cylinder chambers (8) and (10) through a metal tube (30).
Drive the diaphragms 2 and 14 to deform the diaphragm (18),
The work is grasped or released by the claws (32) mounted on the claw mount (16).

[0003]

As shown in FIG. 4, a conventional air chuck body has a stepped bolt insertion hole (22c) formed in the outer diameter of a diaphragm (18). When fixing the bolt (26) to the flange (24) with the bolt (26), the head (26) of the bolt (26) is used.
The end surface of (a) is a step surface (22) of the bolt insertion hole (22c).
d). Therefore, the tightening pressure of the bolt (26) is applied to the outer diameter portion of the diaphragm (18) via the step surface (22d), and the diaphragm (18)
Distortion occurs in the outer diameter portion of. Due to this distortion, an error occurs in the positional accuracy of the claw mounting base (16), and the accuracy of the workpiece gripping force is deteriorated. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem by preventing a tightening pressure of a mounting bolt from being applied to a diaphragm.

[0004]

In order to achieve the above object, the present invention provides a method for manufacturing a machine tool comprising a plurality of bolt insertion holes (66) on the same circle aligned with bolt holes of a flange of a spindle of a machine tool.
(22a) is bored and a cylinder chamber (46) is provided on the side.
(8) The base (34) (2) on which the (10) is formed and the base (3) are placed in the cylinder chambers (46), (8) and (10).
4) A piston (60), (12), (14) slidably disposed in a direction perpendicular to the side surface of (2), and an outer peripheral portion connected to the outer peripheral portion of the base (34) (2) and substantially connected thereto. A diaphragm (48) (18) having a central portion connected to a substantially central portion of the piston (60) (12) (14) and having claw mounts (54) (16) provided on an outer surface side; Air is supplied / discharged from the pneumatic device to the cylinder chambers (46), (8) and (10) to drive the pistons (60), (12) and (14), and is connected to the pistons (60), (12) and (14). In the diaphragm chuck in which the thin portions of the diaphragms (48) and (18) are deformed, bolt insertion holes (66) and (22a) of the bases (34) and (2) are provided in the diaphragms (48) and (18). And located on the same coaxial line Body insertion hole (64) (96) is formed, the cylindrical body insertion hole (64) (96) to the tubular body (68)
(92) is inserted and arranged, and end faces (68a) and (92b) perpendicular to one axial direction of the cylindrical bodies (68) and (92) abut against inner surfaces of the bases (34) and (2). Bolts (38) and (26) arranged and inserted into the cylinders (68) and (92)
Is screwed into the screw hole of the flange.
8) The heads (38a) and (26a) of (26) are pressed against the other ends of the cylindrical bodies (68) and (92) to form the base (34).
(2) The flanges and the end faces (68a) of the cylindrical bodies (68) and (92) are tightened by the bolts (38) and (26).
(92b) and the clamping force of the bolts (38) and (26) is reduced by the diaphragm (4).
8) (18) is not pressed in the axial direction.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral (34) denotes a base body of a chuck body (40) which is detachably attached to an end face of a flange (36) of a spindle of a machine tool, for example, a lathe, by a bolt (38). It is composed of a board-like member.
A tubular portion (34a) is integrally formed vertically at the center of the base (34). On one surface of the base (34), a circular curved surface (42) and a plate-like flat surface (44) having a predetermined width are provided.
The piston housing recess having a predetermined depth is formed, and the recess forms a cylinder chamber (46).

Reference numeral (48) denotes a board-shaped diaphragm, whose outer diameter portion is fixed to the thicker outer diameter portion of the base (34) by bolts (52) via a Teflon packing (50). I have. A tubular portion (48a) is formed at the center of the diaphragm (48), and the inner peripheral surface of the tubular portion (48a) is slidable in the axial direction on the outer peripheral surface of the tubular portion (34a). Mated. On the outer surface of the thin portion (48b) of the diaphragm (48), a claw mounting base (54) for mounting a claw (not shown) for grasping a work is projected. On the inner surface of the thin portion (48b) of the diaphragm (48), a plurality of protrusions (55) are provided so as to protrude from the inner surface of the diaphragm (48) on the opposite side of the claw mounting base (54). These projections (55) constitute a counterbalance with respect to the claw mount (54).

Reference numeral (56) denotes a shift plate, the outer diameter of which is screwed to the inner surface of the diaphragm (48).
Has been fixed by. The shift plate (56)
The inner diameter portion is fitted in the outer peripheral surface of the cylindrical portion (48a) in a sealed state. Reference numeral (60) denotes a disc-shaped piston, which is fitted in a circumferentially curved surface (42) of the cylinder chamber (46) slidably in the axial direction with its outer peripheral surface sealed. The inner diameter portion of the piston (60) is fitted in the sealed state slidably in the axial direction on the outer peripheral surface of the tubular portion (34a).

A ridge pipe formed near the inner diameter of the piston (60) is connected to an end face of a central tubular portion (48a) of the diaphragm (48) by a bolt (62). Reference numeral (64) denotes a cylindrical body insertion hole, and a plurality of holes are formed in the diaphragm (48) at equal intervals on the same circle. A bolt insertion hole (66) is formed in the base (34) at the same position as the cylinder insertion hole (64), and a columnar cylinder insertion recess (66a) is formed integrally with each of the bolt insertion holes (66a). ing. The bolt insertion hole (66)
It corresponds to a standardized bolt hole (67) formed in the flange of the main shaft of the machine tool. (68) is a cylindrical body, which has an intermediate portion (68c), one end portion (68d) having a slightly smaller outer diameter than the intermediate portion (68c), and the one end portion (68).
d) and the other end (68e) having the same outer diameter. A stepped surface (68a) perpendicular to the axial direction is formed in a ring shape at the boundary between the intermediate portion (68c) and the one end (68d). At the boundary between the intermediate portion (68c) and the other end (68e), a step surface (68b) perpendicular to the axial direction is formed in a ring shape.

The cylinder insertion hole (6) of the piston (60)
4) and at a position corresponding to the cylindrical body insertion concave portion (66a),
A guide hole (70) is formed, and an outer peripheral surface of an intermediate portion (68c) of the cylindrical body (68) is fitted in the guide hole (70) in a sealed state and slidably in the axial direction. One end (68d) of the cylinder (68) is inserted into the cylinder insertion recess (66).
a), and the step surface (68a) is fitted to the base (3).
4) is in contact with the inner side surface around the cylindrical body insertion concave portion (66a). The other end (68e) of the cylindrical body (68) is sealingly fitted and disposed in the cylindrical body insertion hole (64), and the cylindrical body (68).
And the inner peripheral surface of the cylindrical body insertion hole (64) forms a bolt head storage recess.

[0010] (72) is a metal air flow tube, the outer tubular portion (72a) and the middle tubular portion (72b).
And a screw formed on the outer peripheral surface of the outer cylindrical portion (72a) with a screw formed on the inner peripheral surface of the tubular portion (34a). It is screwed into the part. The space between the inner peripheral surface of the outer tubular portion (72a) and the outer peripheral surface of the middle tubular portion (72b) constitutes a first air flow passage (74). Is the air hole (7
6) It communicates with the cylinder chamber (46) on one pressure receiving surface (60a) side of the piston (60) via (78).
A second air flow path (8) is provided between the inner peripheral surface of the middle cylindrical portion (72b) and the outer peripheral surface of the inner cylindrical portion (72c).
0), and the flow passage (80) is formed through the groove (82) and the air holes (84) (86) (88) through the piston (6).
0) on the other pressure receiving surface (60b) side.
6). The air flow path (74) (8)
0) communicates with a pneumatic device (not shown). Note that an oil passage is formed inside the inner cylindrical portion (72c).

Next, the operation of the present embodiment will be described. First, a claw corresponding to a work is mounted on the claw mounting base (54). Next, the bolt insertion hole (66) is aligned with the bolt hole (67) of the flange (36) of the main shaft of the machine tool, and the bolt (38) is inserted through the opening at the other end (68e) of the cylinder (68). The chuck body (40) is fixed to the main shaft flange (36) by inserting the bolt 38 into the bolt hole (67) of the main shaft flange (36) by inserting the bolt 38 into the main body (68) and the bolt insertion hole (66). When the bolt (38) is screwed tightly into the bolt hole (67) of the flange (36), an end face (38b) perpendicular to the axial direction of the head (38a) of the bolt (38) is attached to the other end of the cylinder (68). The end surface (68e) is pressed against the end surface, and the pressing force causes the step surface (68a) of the cylindrical body (68) to be pressed against the inner surface of the base (34).

The base (34) is clamped between the step surface (68a) of the cylindrical body (68) and the flange (36) by the tightening force of the bolt (38). ) Is fixed to the flange (36). At this time, the tightening force of the bolt (38) is applied to the end face of the other end (68e) of the cylindrical body (68), and the pressure of the tightening force of the bolt (38) is not applied to the diaphragm (48). Next, the work is inserted into the claw, and high-pressure air is sent from the second air flow passage (80) to the cylinder chamber (46) on the one pressure receiving surface (60b) side of the piston (60).
The air in the cylinder chamber (46) on the other pressure receiving surface (60a) side of the piston (60) is released.

As a result, the piston (60)
It moves inside the cylinder chamber (46) in the middle and left directions, and the thin portion of the diaphragm (48) is deformed, and the claws grasp the work tightly. To release the grasp of the work, the supply of the high-pressure air to the cylinder chamber (46) on the one pressure receiving surface (60b) side of the piston (60) is released. When the chuck body (40) rotates at a high speed by the high-speed rotation of the flange (36) with the claws gripping the work, centrifugal force is generated due to the weight of the claws and the claw mount (54). The thin portion (48b) of the diaphragm (48) tends to deform in the direction in which the claws open. In this state, a centrifugal force is similarly generated in the projection (55). This centrifugal force is applied to the diaphragm (48) in the direction to prevent the pawl from opening.
And the centrifugal force on the outer surface side and the centrifugal force on the inner surface side of the diaphragm (48) cancel each other, thereby reducing the effect of the centrifugal force of the claw and the claw mount (54) on the diaphragm (48). it can.

Next, another embodiment of the present invention will be described with reference to FIG. (2) is a substrate, and the outer diameter of the substrate is
Bolt hole (26) in flange (24) of main shaft of machine tool
, A bolt insertion hole (22a) is formed. A board (4) fixed to a base (2), and a board (4)
The outer diameter portion of the diaphragm (18) fixed to the cylindrical insertion hole (94) is located coaxially with the bolt insertion hole (22a) and has a larger diameter than the bolt insertion hole (22a).
(96) is bored, and the cylinder (92) is slidably fitted in the cylinder insertion holes (94) and (96). The other structure is the same as the structure of the air chuck shown in FIG.

The air chuck body is connected to a flange (24).
When mounting on a machine tool, align the bolt insertion hole (22a) with the bolt hole (25) of the flange (24) of the machine tool,
The bolt (26) is inserted into the cylinder (92) from the cylinder insertion hole (96) of the diaphragm (18), and the bolt (26) is further screwed into the bolt hole (25) of the flange (24). When the bolt (26) is screwed tightly into the bolt hole (25) of the flange (24), the end face of the head (26a) of the bolt (26) perpendicular to the axial direction is a cylinder (92).
The other end surface (92b) of the cylindrical body (92) is pressed against the inner surface of the base (2) by this pressure contact force.

Thus, the base body (2) is formed into a cylindrical body (92).
And the flange (24), the base (2) is fixed to the flange (24). At this time, the tightening force of the bolt (26) is applied to one end surface (92a) of the cylindrical body (92), and the pressure of the tightening force of the bolt (26) is not applied to the diaphragm (18).

[0017]

Since the present invention is constructed as described above, there is an effect that the chuck body can be firmly fixed to the flange of the main shaft of the machine tool without causing any distortion in the diaphragm.

[Brief description of the drawings]

FIG. 1 is a sectional view of a diaphragm type air chuck according to the present invention.

FIG. 2 is an inner side view of the diaphragm.

FIG. 3 is an outer side view of the diaphragm.

FIG. 4 is a sectional view of the prior art.

FIG. 5 is a cross-sectional view of a part of an air chuck, showing another embodiment of the present invention.

[Explanation of symbols]

 2 Base 4 Base 6 Partition wall 8 Cylinder chamber 10 Cylinder chamber 12 Piston 14 Piston 16 Claw mount 18 Diaphragm 20 Bolt 22a Bolt insertion hole 22b Bolt insertion hole 22c Bolt insertion hole 24 Flange 25 Bolt hole 26 Bolt 28 Body 30 Tube 32 Claw 34 Base 34a Tubular portion 36 Flange 38 Bolt 40 Chuck main body 42 Circular curved surface 44 Disc-shaped flat surface 46 Cylinder chamber 48 Diaphragm 48a Cylindrical portion 48b Thin portion 50 Teflon packing 52 Bolt 54 Claw mount 55 Protrusion 56 Shift plate 58 Screw 60 Piston 62 Bolt 64 Cylindrical insertion hole 64a Cylindrical insertion recess 66 Bolt insertion hole 66a Cylindrical insertion recess 68 Cylindrical 70 Guide hole 72 Air flow tube 72a Outer cylindrical part 72b Middle cylindrical part 72c Inner cylindrical portion 74 Air flow passage 76 Air hole 78 Air hole 80 Air flow passage 82 Groove 84 Air hole 86 Air hole 94 Cylindrical insertion hole 96 Cylindrical insertion hole

Claims (1)

[Claims] 1. A plurality of bolt insertion holes (66) on the same circular line corresponding to bolt holes of a flange of a main shaft of a machine tool.
(22a) is bored and a cylinder chamber (46) is provided on the side.
(8) The base (34) (2) on which the (10) is formed and the base (3) are placed in the cylinder chambers (46), (8) and (10).
4) A piston (60), (12), (14) slidably disposed in a direction perpendicular to the side surface of (2), and an outer peripheral portion connected to the outer peripheral portion of the base (34) (2) and substantially connected thereto. A diaphragm (48) (18) having a central portion connected to a substantially central portion of the piston (60) (12) (14) and having claw mounts (54) (16) provided on an outer surface side; Air is supplied / discharged from the pneumatic device to the cylinder chambers (46), (8) and (10) to drive the pistons (60), (12) and (14), and is connected to the pistons (60), (12) and (14). In the diaphragm chuck in which the thin portions of the diaphragms (48) and (18) are deformed, bolt insertion holes (66) and (22a) of the bases (34) and (2) are provided in the diaphragms (48) and (18). And located on the same coaxial line Body insertion hole (64) (96) is formed, the cylindrical body insertion hole (64) (96) to the tubular body (68)
(92) is inserted and arranged, and end faces (68a) and (92b) perpendicular to one axial direction of the cylindrical bodies (68) and (92) abut against inner surfaces of the bases (34) and (2). Bolts (38) and (26) arranged and inserted into the cylinders (68) and (92)
Is screwed into the screw hole of the flange.
8) The heads (38a) and (26a) of (26) are pressed against the other ends of the cylindrical bodies (68) and (92) to form the base (34).
(2) The flanges and the end faces (68a) of the cylindrical bodies (68) and (92) are tightened by the bolts (38) and (26).
(92b) and the clamping force of the bolts (38) and (26) is reduced by the diaphragm (4).
8) A diaphragm-type chuck characterized in that (18) is not pressed in the axial direction.