JPH0531813U - Eccentric check - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a chuck capable of automatically machining a work having a plurality of machining holes or machining axes on a constant pitch circle centering on a point of symmetry with a lathe. [Structure] A power chuck centered on an axis C2 that is eccentric by a distance L from the axis C1 of the outer case 1 aligned with the axis of the main spindle of the lathe to the symmetry point C3 of the workpiece W and the processing holes H1 and H2. 40 is rotatably indexed and supported so as to be movable in the axial direction. The outer case 1 is provided with an indexing drive device having a drive cylinder 66 for rotating the power chuck 40 by 90 degrees around the axis C2, and a detachable positioning member for holding the indexed position of the power chuck 40. Are fixed in correspondence with the outer case 1 and the power chuck 40.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an eccentric chuck suitable for use in machining a plurality of holes arranged in point symmetry or a shaft.

[0002]

[Prior Art]

 In a conventional eccentric chuck, for example, as shown in FIG. 5, a radial guide groove (T groove) 101 is provided on a face plate 100 attached to a spindle of a lathe, and a chuck 103 having a claw 102 along the T groove 101 is provided. It is known that the action of the cylinder 104 moves.

[0003]

[Problems to be solved by the device]

 In such an eccentric chuck, it is easy to machine two holes H1 and H2 in the work W as shown in FIG. This is because the chuck 103 holding the work W may be moved in the radial direction so that the machined holes H1 and H2 coincide with the center of the face plate 100, that is, the center of rotation of the spindle.

However, in such an eccentric chuck, for example, as shown in FIG. 6, it is impossible to machine three or more holes H1 to H4 located on a constant circumference with the symmetry point C3 as the center. Further, even when the two holes are processed as described above, since the chuck is moved in the radial direction, the rotation balance of the entire eccentric chuck is greatly disturbed, which causes vibration.

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides an indexing drive device having a drive cylinder that rotatably supports a power chuck at a position that is eccentric to a shaft center of an outer case and that rotates the power chuck. The interior of the outer case is characterized in that a positioning device for holding the indexing position of the power chuck by a positioning cylinder in the outer case is interposed between the outer case and the power chuck.

[0006]

[Action]

 When machining a workpiece with multiple machining holes or machining axes on a constant pitch circle with respect to the point of symmetry, use a power chuck that can be freely indexed at a position eccentric to the outer case axis center by the pitch circle radius. , Hold the workpiece with the symmetry point of the work and the center of the power chuck aligned. Then, the power chuck is indexed and rotated by the indexing drive device, the processing hole or the processing shaft is positioned at the shaft center of the outer case, and the power chuck is positioned and processed by the positioning device.

[0007]

【Example】

 In FIG. 2, the outer case 1 has a predetermined amount in the radial direction with respect to the case body 2, the back cover 3 and the axis C1 of the outer case 1 (matches the distance between the symmetrical point C3 of the workpiece W and the processing holes H1, H2) L And a cylindrical guide 4 having an axial center C2 of the inner surface 4a at a position eccentric only. A stepped hole 5 is formed in the case body 2 with the same axis as the inner surface 4a of the cylindrical guide 4. The medium-diameter hole 5b of the stepped hole 5 is a cylinder hole, and the hollow piston 6 is fitted in the medium-diameter hole 5 so as to be movable in the axial direction by a predetermined amount, and the front piston rod 7 of the piston 6 becomes the small-diameter hole 5c. It is fitted. The rear piston rod 8 of the piston 6 penetrates an end cover 9 which is fixed to the step portion 5d of the stepped hole 5 and closes the medium diameter hole 5b, and a positioning cylinder 10 is formed as a whole. The cylinder 10 is supplied with pressure fluid from fluid pipes 12 and 13 connected to a cap 11 integrally fixed to the back lid 3 through fluid passages 14 and 15 formed in the back lid 3 and the case body 2. Is becoming

In the hollow hole 6 a of the piston 6 of the cylinder 10, a cylinder body 22 of the chuck working cylinder 20 is rotatably supported via a bearing 21 coaxially with the piston 6. The front end of the cylinder body 22 of the chuck operating cylinder 20 is a mounting flange 23. A piston 26, which is prevented from rotating by a pin 25, is fitted in a cylinder hole 24 of the cylinder body 22 so as to be axially movable, and a piston rod 27 integral with the piston 26 penetrates a central wall 28 and projects forward. The rear end of the cylinder body 22 is closed by an end cover 29. The end cover 29 has a small-diameter shaft 29a integrally protruding at the rear portion. A pinion 61, which constitutes a part of the index drive device 60, is keyed to the small diameter shaft 29a. A pipe 30 penetrating the cap 11 is fitted with a hole 26a at the axial center of the piston 26 so as to be movable in the axial direction, supplies a pressurized fluid to the front cylinder chamber 31a, and is connected to the cap 11 by a pipe 32. The pressure fluid is supplied to the rear cylinder chamber 31b through the gap between the pipe 30 and the center hole 29a of the end cover 29.

A power chuck 40 is integrally fixed to the mounting flange 23 of the cylinder body 22 with its axis aligned with the axis of the cylinder 20. This power chuck is a so-called finger chuck, in which the piston rod 27 is connected to the pull rod 41, and by pushing and pulling the pull rod 41 in the axial direction, the spider 42 inside the chuck 40 moves back and forth in the axial direction. The claw shaft 43, which is connected to the spider 42, moves back and forth, and the cam groove 44 formed on the outer circumference of the claw shaft 43 engages with the fixing pin 45 to separate the claw 46 from the work W, and FIG. The claw 46 moves in the axial direction while turning between a standby position indicated by a two-dot chain line and a clamp position where the claw 46 clamps the work W (solid line in FIG. 1).

To the back surface of the power chuck 40, one positioning member 52 fixed to the front surface of the case body 2 and the other positioning member 51 that is disengaged by the action of the positioning cylinder 10 are fixed. The positioning members 51 and 52 are provided with a large number of meshing teeth 51a and 52a that face each other on opposite end faces and mesh with each other at equal pitches in the circumferential direction, and a power chuck indexed by an indexing drive device 60 described later. A positioning device 50 that holds the indexed positions of 40 is configured.

Next, the index drive device 60 will be described. As shown in FIG. 3, a cylinder hole 62 is formed on one side of the large diameter hole 5a of the case body 2 of the outer case 1 orthogonal to the axis of the pinion 61. A piston 64, which projects a rod 63 toward the other side, is fitted in the cylinder hole 62 so as to move in the axial direction, and a rear portion of the cylinder hole 62 is closed by an end cap 65 to form a drive cylinder 66. In the cylinder chambers 64a, 64b before and after being partitioned by the piston 64, pressurized fluid is supplied from the flow paths 68, 69 communicating with the pipes 67a, 67b provided in the cap 11 via fluid paths not shown. It is designed to be supplied and discharged.

A rack 70 is engraved on the upper surface of the piston rod 63, and the rear side of the rack 70 is removed as shown in FIG. 2, and when the positioning members 51 and 52 are in mesh with each other, the rack 70 and the pinion are engaged. The rack 70 and the pinion 61 engage with each other only when the positioning cylinder 10 moves the power chuck 40 forward and the positioning members 51 and 52 are disengaged from each other. The tip of the rack 70 is guided by a guide bush 71 of the case body 2 and is prevented from rotating by a pin 72. A stopper 73 is mounted on the guide bush 71 so that its position can be adjusted, and the stopper position is adjusted so that the pinion 61, that is, the power chuck 40, can be rotated by 90 degrees at the stroke ST of the rack 70.

A jig base 80 for fixing a work is fixed to the front surface of the power chuck 40, and a machining hole is symmetrically formed to the left and right with respect to a point of symmetry (which coincides with the axis C2 in FIG. 1) C3. The work W having H1 and H2 is positioned by the positioning pins 81 and 82. Reference numerals 83 and 84 denote chip discharge holes provided corresponding to the machining holes H1 and H2 of the work W.

With the eccentric chuck having the above configuration, the plurality of processing holes H1 and H2 on a constant circumference with respect to the symmetry point C3 are processed as follows. The eccentric chuck is mounted on the rotary spindle with the axis C1 of the outer case 1 aligned with the axis of the rotary spindle of the lathe. When the processing of the previous work W is completed, the power chuck 40 and the outer case 1 have the positional relationship in the circumferential direction of FIG. The piston 26 of the chuck operating cylinder 20 is moved forward from the state shown in FIG. 1 with the rotating main shaft stopped and the positioning members 51, 52 engaged with each other. Then, the pawl 46 pivots to the standby position while distant from the processed work to the front, and unclamps the work. Then, the next work W is mounted on the jig base 80, the piston 26 of the chuck operating cylinder 20 is retracted, and the pawl 46 is retracted and rotated to clamp the work W on the jig base 80. At this time, the symmetry point C3 of the work W coincides with the rotation center of the power chuck 40, that is, the axis C2 of the inner surface 4a of the cylindrical guide 4. Therefore, one machining hole H1 of the work W coincides with the axis C1 of the outer case 1, that is, the rotation center of the eccentric chuck.

Then, the spindle of the lathe is rotated to first machine the machining hole H1. When the machining is finished, the rotation of the spindle of the lathe is stopped, and then the piston 6 of the positioning cylinder 10 is advanced from the retracted end to the advanced end in FIG. 1 while holding the work W by the power chuck 40. As a result, the pinion 61 meshes with the rack 70, the meshing teeth 51a, 52a of the positioning members 51, 52 are disengaged, and the power chuck 40 becomes rotatable. Next, when the piston 64 of the drive cylinder 66 starts to move forward from the retracted end shown in FIG. 3 and moves forward by the stroke ST until the tip of the piston rod 63 contacts the stopper 73, the chuck 70 and the pinion 61 mesh with each other to drive the chuck drive cylinder 20. That is, the power chuck 40 rotates 90 degrees about the axis C2. Next, the piston 6 of the positioning cylinder 10 is returned from the forward end to the state shown in FIG. Then, the positioning members 51 and 52 are engaged with each other, the indexed position of the power chuck 40 is held, and the pinion 61 is disengaged from the rack 70.

Since the machined holes H1 and H2 are displaced by 180 degrees about the symmetry point C3, the power chuck 40 must be rotated by the remaining 90 degrees. Therefore, when the pinion 61 is disengaged from the rack 70, the piston 64 of the drive cylinder 66 is returned from the forward end to the backward end shown in FIG. Then, in the same manner as described above, the positioning cylinder 10 is actuated to move the power chuck 40 forward to disengage the positioning members 51 and 52, and the driving cylinder 66 further rotates the power chuck 40 by 90 degrees, and then the positioning is performed. The cylinder 10 engages the positioning members 51 and 52, and holds the power chuck 40 at a position 180 degrees swivel from the initial position. Then, the drive cylinder 66 returns the piston 64 to the retracted end for the next indexing operation. When the 180-degree index is completed in this way, the machining hole H2 is aligned with the axis C1 of the outer case 1, that is, the axis of the rotary spindle of the lathe. Do. When machining two holes with the machining holes H1 and H2, the power chuck 40 performs indexing rotation around the eccentric shaft center C2, so if the rotation balance of the entire eccentric chuck is taken in advance, Compared to an eccentric chuck in which the entire chuck moves in the radial direction, rotational balance, that is, imbalance is less likely to occur, and vibration is less likely to occur.

In this embodiment, the work having two machined holes is explained, but as shown in FIG. 6, three or more machined holes H1 to H4 are arranged on the pitch circumference diameter 2L centering on the symmetry point C3. Needless to say, it is possible to process a work that has a grip. Further, instead of the hole shown in FIG. 6, even a work having a protruding machining shaft can be easily machined by using a parting cutting tool, and can also be used for machining a crankshaft.

[0018]

[Effect of the device]

 As described above, according to the eccentric chuck of the present invention, the machining holes or machining axes of a workpiece having a plurality of machining holes or machining axes on a constant pitch circle centering on the point of symmetry are cracked one after another while being chucked. It can be taken out and automatically processed continuously. Moreover, since the indexing is a rotary motion, if the rotation balance of the entire eccentric chuck is set in advance, it is possible to suppress the collapse of the rotation balance even if the indexing is performed, compared to the case where the power chuck is moved in the radial direction. The vibration generation can be reduced. Furthermore, since a machine tool with high production efficiency, such as a lathe, can drill multiple holes, it also has the effect of improving productivity.

[Brief description of drawings]

FIG. 1 is a front view of an eccentric chuck of the present invention.

FIG. 2 is a vertical sectional view of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an IV view of FIG. 1.

FIG. 5 is a diagram showing a conventional technique.

FIG. 6 is an explanatory diagram of a work shape.

[Explanation of symbols]

1 outer case, 10 positioning cylinders, 4
0 power chuck, 50 positioning device, 60 indexing drive device, 66 drive cylinder, C1 outer case shaft center, C2 power chuck shaft center

Claims (1)

[Scope of utility model registration request] 1. An outer case is internally provided with an indexing drive device having a drive cylinder for rotatably supporting a power chuck at a position eccentric to a shaft center of the outer case and rotating the power chuck for indexing. An eccentric chuck characterized in that a positioning device for holding the indexed position of the power chuck by a positioning cylinder in the outer case is interposed between the outer case and the power chuck.