JPS62140708A - Floating chuck - Google Patents

Abstract

PURPOSE:To enlarge a clamping area, by forming in multi-stage at least two kinds of a cam face engaging with the outer peripheral face of a large diameter work and a cam face engaging with the outer peripheral face of a small diameter work, on the inner end portions of eccentric cams of a floating chuck. CONSTITUTION:When engagement of engagingly locking teeth 35 with saw teeth 36 is released by driving of a cylinder mounted through a bracket 40, a rotary face plate 13 and a floating member 21 respectively fixed to the teeth 35, 36 become rotatable. And the floating member 21 is rotated in relation to the rotary face plate 13 by energizing force of a screw 37 provided on the circumferential 3 positions and a pivot 26 pivoting eccentric cams 27 are rotated with the C axis as a center and the three eccentric cams 27 are rotated with the pivot 26 as a center. And a work WA retained in a center 12 is clamped to inner end portions 27a when the work has a large diameter and to inner end portions 27b when it has a small diameter respectively and when the rotary face plate 13 is turned, the work is turned through a pin 30 and the eccentric cams 27 without being pressed in the radial direction.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a floating chuck that engages with the outer peripheral surface of a round bar-shaped workpiece supported by the center of a machine tool and rotates the workpiece. It is.

[Prior art] In the conventional floating chuck,
As shown in Japanese Patent No. 22623, a plurality of eccentric cams are used to clamp the workpiece as it rotates. When clamping a workpiece that is re-centered on this small number of eccentric cams, the member to which the eccentric cams are attached is It is designed to float relative to the workpiece.

[Problems to be solved by the invention] Since conventional eccentric cams have only one cam surface for clamping workpieces, for example, there is a large difference in the outer diameter of two types of workpieces clamped by eccentric cams. In this case, eccentric cam failures are likely to occur at the beginning of the year.

However, if the outer diameter of the workpiece is too large for the clamping range of the eccentric cam, there is a problem that when removing the workpiece from the eccentric cam, the workpiece gets caught due to the opening of the centrifugal cam. Occurred. Also, if the outer diameter of the workpiece is too small for the clamping range of the eccentric cam,
Due to poor clamping of the eccentric cam, a problem occurred in which the workpiece slipped against the eccentric cam during machining.

The present invention solves the problems in the prior art described above and has a ramp range that is larger than the clamping range of the conventional eccentric cam. , a clamp failure will occur.
Another object of the present invention is to provide a floating chuck equipped with an eccentric cam that does not cause a workpiece to be caught during removal.

[Means for Solving the Problems] In order to achieve the above object, the present invention (1. A drive source rotatably mounted on a workpiece headstock equipped with a center supporting one end of a workpiece. a rotating face plate rotated by a rotating face plate, a floating member supported rotatably and radially movably with respect to the rotating face plate, and an appropriate number of supports attached to the floating member in a manner projecting forward from a front end portion. The inner end has a cam surface that is swingably attached to each of the support shafts and engages with the outer circumferential surface of the workpiece. an eccentric cam that protrudes forward and engages with a drive pin attached to the rotary face plate; A tension spring that rotates the driving tapping pin in a direction in which the eccentric cam engages with the workpiece, and a floating member that rotates against the biasing force of the tension spring to release the engagement between the eccentric cam and the workpiece. In the floating chuck, the eccentric cam has a first cam surface that engages with the outer circumferential surface of the workpiece having a large diameter, and a second cam surface that engages with the outer circumferential surface of the small diameter workpiece at the inner end of the eccentric cam. The cam surface of at least two pillars is formed in multiple stages.

[Embodiment] Next, the present invention will be explained with reference to the drawings showing examples.

In FIGS. 1 and 2, the headstock 10 is movably supported on a table 11 in a machining area (for example, a grinding machine), and the center mounting hole (not shown) of the headstock 10 is ) is attached to the rear end of the center 12 which supports the register hole W△1 drilled at 1110 in the center of one end of the workpiece WA. 13 is rotatably mounted concentrically with the center 12. This rotating face plate 13 forms the base of the flow grip V-tsuku, and a pulley (not shown) is integrally formed therein.
The pulley is rotated by a drive source via a belt. The support member 14 has a cylindrical portion 15 in which the diameter of the shaft hole 15a is slightly larger than the diameter of the center 12, and rear and front flange portions 16 and 17 forming support end surfaces perpendicular to the axis at both ends of the cylindrical portion 15. are doing.

The support member 14 has its cylindrical portion 15 concentrically IM 1+13 with respect to the center 12, and the support end surface 16a of the rear flange portion 16 is attached to the end surface 13a of the rotating face plate 13. This support member 14 has rolling bearings 18.19 and 20 arranged on the outer peripheral surface 15b of the cylindrical portion 15 and the support end surfaces 16a and 17a of both flange portions 16.17.
'3, through these rolling bearings 18, 19 and 20, (
The inner periphery and left and right end portions of the boss portion 22 of the engraving member 21 mentioned above are guided and held. J'3, since the inner diameter of the boss portion 22 of the floating member 21 is larger than the outer diameter of the rolling bearing 18, the floating member 21 is rotatable with respect to the support member 14 and , is movable in the radial direction of the cylindrical portion 15 of the support member 14. The flowbung member 21 has its boss portion 2
2, there is a disc part 23 with a large outer diameter and saw teeth 36 on the outer peripheral surface. There is a ring-shaped annular portion 24 smaller than the outer diameter of the disk portion 23. An annular member 25 is attached to the front surface of the annular portion 24 so as to cover the front end surface of the support member 14 from the outer circumferential direction.

This annular member 25 is provided with three pivot shafts 26 protruding from three equal positions on the circumference, extending to the right of an axis parallel to the center PAC of the center 12, and each pivot shaft 26 is provided with an eccentric cam 27, which will be described later. Mounted so that it can swing. Also, each division @26
An annular retaining plate 28 is attached to the front end surface of the eccentric cam 27 in order to prevent the eccentric cam 27 from protruding by 11 iG from the shaft 26.

Here, the eccentric cam 27 differs from conventional eccentric cams in that the cam surface for clamping the workpiece is divided into two. Specifically, as shown in FIGS. 2 and 3, the eccentric gnome 27 is located near the cam surface and has a predetermined width and thickness.
9i on the center 12 side from the pivot 26: A first cam surface 27a and a second cam surface 27b are formed in parallel at a predetermined interval in the thickness direction. And the ring-shaped member 2
The distance from the center line C of the center 12 of the first cam surface 27a on the side closer to 5 is longer than the distance from the center line C of the center 12 of the second cam surface 27b. Therefore, the first cam surface 27a engages with the outer circumferential surface of the large-diameter flange WA2 of the type A workpiece WA, and the second cam surface 27b engages with the third cam surface 27b, as shown in FIG. As shown in the figure, the workpiece W
The outer diameter of the flange WA2 is smaller than the outer diameter of the flange WA2 (which is engaged with the flange WB2 of the B Mi workpiece WB having a flange WB2 of The eccentric cam 27 is formed so that its radius in the counterclockwise direction from the center thereof gradually increases.An engagement groove 27c is cut in the vertical direction of the end opposite to the cam surface side of the eccentric cam 27. This engagement 127c has an arc-shaped elongated hole 31 that is implanted in the rotating face plate 13 and provided in the floating member 21.
The tip of the drive pin 30 that protrudes through the drive pin 30 is fitted into the drive pin 30. Here, since the hole J installed in the floating ff1X material 21 is a long hole 31, the floating member 21
Insert the first pin 30 in the C slot 31 against the rotating face plate 13.
It can be rotated within the range of movement.

On the end face 13a of the rotating face plate 13, an annular floating part (
A wheel member 34 having an outer diameter that is approximately the same as the outer diameter of Δ21 is fixed, and locking teeth 35 are formed on the outer peripheral surface of this wheel portion (Δ34). pin 32 planted in and floating part 21
Since the ends of the tension springs 37 are respectively attached to the pins 33 planted at three equal positions on the circumference of the floating member 21, the floating member 21 is moved in the direction indicated by the arrow in FIG. It is receiving a rotational force in the direction. And the tension spring 37
When the floating member 21 is rotated in the direction of arrow A, the engagement groove 27c at the outer end of the eccentric cam 27 is locked by the drive pin 30 and does not move, and the pivot 26 moves in the direction of the arrow. Therefore, the OTl and second cam surfaces 27a and 27b of the eccentric cam 27 are rotated in the direction of the solid arrow a. When the A type workpiece WA is attached to the center 12, the first cam of the eccentric cam 17 and the pivot shaft 27a of the eccentric cam 17
The radius from the center of 6 increases is the flange W of the workpiece WA.
It is pressed against the outer peripheral surface of A2 and clamps the workpiece W△.

Next, explaining the fat 61 for unclamping the workpiece WA, the horizontal part 40a of the 1-shaped support bracket 40 is fixed to the upper surface of the headstock 10, and the upper end of the vertical part 40b of the support bracket 40 is fixed to the upper surface of the headstock 10. A cylinder 41 whose axis is vertical is attached via a block 42. A W descending part I4 is connected to the piston rod 43 of the cylinder 41, and this elevating member 44 is connected to each guide roller 45a of the guide part 45, 46, 47 fixed to the side wall of the vertical part 40b of the support bracket 40. , 46a, 4
J to 7a is guided so that 71 downward movement is possible. The lifting member /I /I is provided with a support arm 48 that protrudes above the rotating face plate 13.
The tip of I8 is equipped with a detent notch 50a that engages from the normal direction with the locking teeth 35 of the wheel member 34 fixed to the rotating face plate 13. 51 is installed. The cylindrical cylinder 50 is held by a compression spring 52 installed in the holding cylinder 51.
It is pressed in the direction protruding from 51, and usually that.
The front end position is set by a stopper 53 formed on the outer circumference of the double chain.

At the lower end of the tt descending member/l/I, there is a floating part shrine 2.
Ratchets 1 to 55 that engage in the tangential direction with saw teeth 36 formed on the outer periphery of ratchet 1 are swingably mounted on a pivot shaft 56. This ratchet 55 is provided with an engaging moment by tension springs 57 attached to both ends of the ratchet 55 and the elevating member 44.
4, near the rising end of the guide part 47 and comes into contact with the round stopper bolt 58, which causes the sawtooth 36 to
The engagement that occurs is released.

When the piston rod 43 of the cylinder 41 is lowered from the solid line state (not shown in FIG. 1), the lifting member 44 and the support arm 4
8 is lowered, and the detent notch 5Qa and ratchet 1~
55 engages with the locking teeth 35 and the saw teeth 36, respectively. As a result, the rotary face plate 13 and each drive shaft 30 installed on the rotary face plate 13 are prevented from rotating, but the ratchet 5
5 (move in the tangential direction while being engaged with the sawtooth 36, and rotate the floating member 21 in the direction opposite to arrow A).

The lowering t of the elevating member 44 after the detent notch 50a is engaged with the locking tooth 35 is made possible by the compression spring 52 being compressed. Then, when the floating part 21 is rotated in the direction opposite to the arrow A and each Jffi@26 is rotated in the direction of the dashed arrow, the eccentric cam 17 is rotated in the opposite direction to that when clamping. Workpiece WA is unclamped.

Note that at the ascending end position of the elevating member 44, the locking notch 5o is completely disengaged from the ratchet 55, so that the rotation of the rotary face plate 13 is not restrained at this time.

Next, the operation of this embodiment will be explained. With each eccentric cam 27 of the floating chuck in an unclamped state, after the unprocessed workpiece W△ is attached to the center 12 of the grinding machine, the cylinder 41 When the screws 43 are raised, the locking teeth 35 of the wheel member 34 fixed to the rotating face plate 13 engage with the detent nogs 50a of the first movement cylinder 50, and the floating member 21 is rotated. The saw m36 and the ratchet 55 are disengaged. As a result, the rotation direction plate 13 and the floating member 21 are rotatable, but the rotation direction plate 13 is stopped because it does not receive the rotational force from the drive source. On the other hand, the floating member 21 is rotated in the direction of the arrow by the biasing force of the tension spring 37. This results in 3
The eccentric cam 27 of the cage is rotated in the direction of the solid arrow ah, and its cam surface 27a presses and clamps the outer circumference of the collar WA2 of the workpiece WΔ. 1 In addition, when the rotation direction plate 13 is rotated, each eccentric cam 27 has a rotation face plate 1 which is transmitted through the drive pin 30 without slipping against the grinding resistance.
3 rotational force can be transmitted to the flange portion WΔ2 of the workpiece WA.

Next, when the workpiece to be ground by this grinder changes to eight types of workpieces WB, the flange part WB2 of this workpiece WB1 is changed to an eccentric cam as shown in FIG. It is mounted on the center 12 in a state facing the second cam surface 27b of No. 27. The clamping and unclamping of the workpiece WB by the second cam 27b is performed by the first cam 27a.
Clamping and unclamping of A is performed in the same manner.

In this embodiment, there is no relative movement in the axial direction between the center supporting the workpiece f'1 and the floating part H. However, it is also possible to make the center and the floating member movable relative to each other in the axial direction. By doing this, it is possible to increase the number of cam surfaces of the 1-center cam.

[Efficacy! I! ] As is clear from the above description, the present invention clamps a workpiece of 70 = ching chuck (at least 52 types of cam surfaces, including the first and second cams, are formed in parallel on the cam surface of the spiral cam). Since the cam surface is multi-staged and both cam surfaces are used to clamp workpieces having different outer diameters, it is possible to more reliably clamp workpieces with a larger difference in outer diameter than the conventional eccentric cam having a single cam surface.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view (partially shown in cross section) of a headstock with a floating chuck attached, and FIG. 2 is a partial cross section of FIG. 1. Fig. 3 is an explanatory diagram of the eccentric clamp;
Figure (a) shows the clamped state of a large-diameter workpiece, and Figure 3 (b) shows the clamped state of a small-diameter workpiece. 10... Headstock 13... Rotating face plate 17...
・Supporting member 21...Floating member 27...
・Eccentric cam 27a...First cam and near b...
Second cam surface 30... Drive pin 35... Locking tooth
36...Sawtooth 37...Tension spring 41...
・Cylinder 4/l... Stomach member 50a... Detent notch 55... Latch W△, WB...
・Workpiece patent applicant Yutaka II ] Yoshi Co., Ltd. Toyota Motor Corporation representative J! ! People Patent Attorney Hiroma Okawa Patent Attorney Akio Maruyama Figure 1 Figure 3 (A) Figure 3 (B)

Claims (1)

[Scope of Claims] A rotating face plate that is rotatably attached to the headstock of a machine tool on which a center that supports one end of a workpiece is mounted and rotated by a drive source; and a rotating face plate that is rotatable and movable in a radial direction with respect to the rotating face plate. a floating member supported by the floating member, an appropriate number of support shafts attached to the floating member in a manner projecting forward from the front end surface, and a suitable number of support shafts attached to each of the support shafts so as to be swingable and attached to the outer peripheral surface of the workpiece. an eccentric cam having an engaging cam surface at an inner end and an outer end protruding forward through the floating member to engage a drive pin attached to the rotary face plate; a tension spring that is attached to the rotating face plate and the floating member, respectively, and rotates the floating member relative to the rotating face plate to rotate the drive pin in a direction in which the eccentric cam engages with the workpiece; In the floating chuck, the floating chuck is equipped with a release means that rotates the floating member against the urging force of the eccentric cam and releases the engagement between the eccentric cam and the workpiece, wherein the inner end of the eccentric cam has a large diameter workpiece. A first cam surface that engages with the outer peripheral surface of the work piece and a second cam surface that engages with the outer peripheral surface of the small diameter workpiece.
A floating chuck characterized in that at least two types of cam surfaces are formed in multiple stages.