JPH08197314A - Chuck - Google Patents

Abstract

PURPOSE: To provide a chuck, the external dimensions of which are small, and in which holding force of an auxiliary jaw is kept constant even when the number of revolutions is changed during machining. CONSTITUTION: A plunger 25 of an auxiliary cylinder 28 can be freely moved in the direction of the axis C of rotation. An auxiliary jaw 38 connected to the plunger 25 is divided into a front part and a rear part about a supporting pin 37, and the masses of the two parts are set to the same value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck for gripping and releasing a thin cylindrical work such as a housing of a torque converter or a compressor.

[0002]

2. Description of the Related Art A conventional chuck 1A will be described with reference to FIG. 3. A plurality of main claws 6A are supported by a chuck body 2A so as to be swingable in a radial direction, and the main claws 6A can be moved back and forth in the chuck body 2A. Is engaged with the drawbar 12A that is inserted into the chuck body 2 and the rear end of the drawbar 12A is
The main claw 6 is connected to the piston rod of the rotary cylinder (not shown) at the rear of the main shaft to which A is attached,
A is configured to hold and release the work W, and a plurality of auxiliary claws 38A are supported by the chuck body 2A so as to be swingable in the radial direction via support pins 37A. A plurality of auxiliary cylinders 28A are provided corresponding to the auxiliary claws 38A.
8A is arranged so that its plunger 25A moves in the radial direction, and the plunger 25A of the auxiliary cylinder 28A is
The tip and the non-grasping end of the auxiliary claw 38A are pivotally attached, and the auxiliary cylinder 28A is configured so that the auxiliary claw 38A additionally grips the work W gripped by the main claw 6A. It was intended to prevent chatter and the like during processing when gripping W and to perform stable processing.

[0003]

The conventional chuck 1 described above.
In A, the auxiliary cylinder 28A has its plunger 25A.
Was arranged so as to move in the radial direction, there was a problem that the outer dimensions of the chuck body 2A became large. Further, in the conventional chuck 1A, when the chuck is rotated, centrifugal force acting on each of the front portion and the rear portion divided around the support pin 37A of the auxiliary claw 38A, and the plunger 25A movable in the radial direction. The centrifugal force that acts on the auxiliary claw 38A affects the gripping force of the auxiliary claw 38A, but the balance of these centrifugal forces is not adjusted. Therefore, when constant peripheral speed machining is performed, the rotation speed changes during cutting. Therefore, there is a problem that the gripping force of the auxiliary claw 38A fluctuates and stable machining cannot be performed. Further, the centrifugal force around the support pin 37A is taken into consideration in consideration of the centrifugal force acting on the plunger 25A which is a member different from the auxiliary claw itself. Balancing was a daunting task. Further, the chuck body 2A must be provided with a plurality of auxiliary cylinders 28A, and a plurality of insertion holes and a large number of fluid passages for operation must be formed corresponding to these, which causes a problem of high processing cost. there were.

[0004]

In order to solve the above-mentioned problems, according to claim 1, the main cylinder is operated by a plurality of main claws for holding and releasing a work by the action of a rotary cylinder, and an action of an auxiliary cylinder provided in a chuck body. A chuck comprising a plurality of auxiliary claws for auxiliary gripping of a work gripped by a claw, wherein the auxiliary cylinder is arranged so that its plunger moves parallel to a rotation axis of the chuck. According to the second aspect of the present invention, the intermediate portion of the auxiliary claw is swingably supported by the chuck body with the support pin, and the anti-grasping end of the auxiliary claw is pivotally attached to the plunger of the auxiliary cylinder to prevent the auxiliary claw from rotating the chuck. At this time, the centrifugal force acting on the front side portion and the rear side portion divided about the support pin as a center is configured to be substantially the same.
The auxiliary soft jaw and the balance weight are detachably provided on the auxiliary nail body, and the auxiliary cylinder is constituted by one annular cylinder.

[0005]

In the first aspect of the present invention, since the plunger of the auxiliary cylinder is arranged so as to move parallel to the rotation axis of the chuck, the outer dimension of the chuck can be set to a small value. Further, in claim 2, the plunger of the auxiliary claw is immovable in the radial direction, the centrifugal force acting on the plunger does not affect the gripping force of the auxiliary claw, and the auxiliary claw has a front part and a rear part. Since the balance of the centrifugal force acting on the side portion is adjusted, the gripping force of the auxiliary pawl is constant even if the peripheral speed is machined and the rotation speed fluctuates during cutting. Further, according to claim 3, when the workpiece is changed, the auxiliary soft jaw is replaced with one having a different gripping position, and the balance weight is replaced with one corresponding to the exchanged auxiliary soft jaw. Balance adjustment can be easily performed. According to the fourth aspect, since the auxiliary cylinder is composed of one annular cylinder, it is possible to reduce the number of fluid passages provided in the chuck body and reduce the processing cost.

[0006]

EXAMPLE An example of the chuck 1 will be described with reference to FIGS. A plurality of (three in the drawing) main claw fitting grooves 3 are formed in the chuck body 2 at equal intervals in the circumferential direction. The main claw fitting groove 3 is substantially L-shaped via the support pin 5.
A character-shaped main claw 6 is supported so as to be swingable in the radial direction.
On this main claw 6, a main soft claw 7 is detachably attached to a gripping end of a main claw main body 6a, and an engaging portion 8 to be engaged with an engaging recess 13 described later is provided on an opposite gripping end. Has been formed.
A drawbar 12 is fitted in a center hole 11 formed in the center of the chuck body 2 so as to be movable in the rotation axis C direction. Engagement recesses 13 are formed in the drawbar 12 at equal intervals in the circumferential direction corresponding to the plurality of main claws 6. The rear end of the draw bar 12 is connected to the tip of a piston rod of a rotary cylinder (not shown) arranged at the rear end of the main shaft of a lathe having the chuck body 2 attached to the front end. Therefore, the main claw 6 swings by the action of the rotating cylinder to release and hold the work W.

A work contact member 15 with which the bottom surface of the work W abuts is screwed to the front surface of the chuck body 2. A slide hole 16 is formed in the rear end surface of the work contact member 15, and the tip end portion of the draw bar 12 is slidably fitted in the slide hole 16 so that the slide hole 16 and the draw bar 12 can be connected. A communication chamber 17 is formed with the tip surface. A ring member 21 is attached to the front surface of the chuck body 2, and the outer circumference of the front end portion of the ring member 21 has a small diameter portion 21a.
Is formed. An annular support member 23 that supports an auxiliary claw 38 described later is screwed to the upper end surface of the ring member 21. A plunger 25 is fitted on the outer circumferences of the ring member 21 and the support member 23 so as to be movable in the rotation axis C direction. The inner peripheral surface of the plunger 25 has a piston portion 25 that slides on the outer peripheral surface of the small diameter portion 21a of the ring member 21.
a is formed. A spring 27 that biases the plunger 25 rearward is interposed between the piston portion 25a and the support member 23. The ring member 21, the support member 23, and the plunger 25 are used to support the auxiliary cylinder 28.
(Annular cylinder) is configured. Auxiliary cylinder 28
The front cylinder chamber 29a is opened to the outside air via a communication passage 31 formed in the plunger 25. Further, the rear cylinder chamber 29b is communicated with the communication chamber 17 through a communication passage 32 formed in the ring member 21, the chuck body 2 and the work contact member 15. A pressure fluid supply passage 34 is formed through the center of the drawbar 12, and the pressure fluid supply passage 34 is connected to a pressure fluid supply source via a piston rod and a rotary joint of a rotary cylinder (not shown).

Next, on the front end surface of the support member 23, support portions 36 of a plurality (four in the drawing) of auxiliary claws 38 are formed to project in the circumferential direction. The support pin 36 has a support pin 3
A substantially T-shaped auxiliary claw 38 is swingably supported via 7. The auxiliary claw 38 is configured such that an auxiliary soft claw 39 and a balance weight 40 are detachably attached to the front and rear portions of the gripping end of the auxiliary claw main body 38a. Also,
The auxiliary claw 38 holds the support pin 37 in the work gripping state.
The mass of the front portion and the rear portion divided by the straight line L passing through the center of the auxiliary claw 38 has substantially the same value, and therefore acts on the front portion and the rear portion of the auxiliary pawl 38 during chuck rotation. The centrifugal force is about the same. Further, a portion corresponding to the auxiliary claw 38 is formed on the front end surface of the plunger 25 so as to project from the connecting portion 41. This connecting portion 41 is
It is connected via a connecting pin 42 to a connecting groove 43 formed at the opposite gripping end of the auxiliary claw 38. Therefore, when air or oil fluid is supplied from the pressure fluid supply source, the fluid is supplied to the rear cylinder chamber 29b via the supply passage 34, the communication chamber 17 and the communication passage 32, and resists the biasing force of the spring 27. When the plunger 25 moves forward to swing the auxiliary claw 38 in the work gripping direction and when the supply of the fluid from the pressure fluid supply source is stopped, the urging force of the spring 27 moves the plunger 25 backward and assists. The pawl 38 is adapted to swing in the workpiece releasing direction.

Next, the chuck 1 constructed as described above.
The operation of will be described. First, the bottom surface of the work W is brought into contact with the work contact member 15 to rotate the rotary cylinder (not shown).
When the drawbar 12 is moved rearward by the action of, the main claw 6 swings around the support pin 5 in the gripping direction due to the engagement between the engagement recess 13 of the drawbar 12 and the engagement part 8 of the main claw 6. The work W is gripped. When a fluid is supplied to the fluid supply passage 34 of the draw bar 12 from a pressure fluid supply source (not shown), the auxiliary cylinder 2 is passed through the communication chamber 17 and the communication passage 32.
The fluid is supplied to the rear cylinder chamber 29b of No. 8, and the plunger 25 moves forward against the biasing force of the spring 27. Then, the engagement between the connecting pin 42 and the connecting groove 43 causes the auxiliary claw 38 to swing about the support pin 37 in the gripping direction,
The front part of the work W gripped by the main claw 6 is auxiliary gripped. When the chuck 1 is rotated in this state to perform constant peripheral speed machining, the centrifugal force acting on the plunger 25 that is not movable in the radial direction does not affect the gripping force of the auxiliary pawl 38, and the auxiliary pawl 38 has a front portion. Since the centrifugal forces acting on the rear part and the rear part are balanced, stable gripping force of the auxiliary pawl 38 does not fluctuate and stable machining can be performed even if the rotational speed fluctuates during cutting. . Also, work W
At the time of changeover, the auxiliary claw 38 of the auxiliary claw 38 is replaced with one having a different gripping position in the chuck radial direction, and the balance weight 40 is replaced with a corresponding one of the replaced auxiliary claw 39. Support pin 3
The balance around 7 can be easily adjusted.

As described above, in the chuck 1 of this embodiment,
Since the work W is gripped by the auxiliary claws 38 together with the plurality of main claws 6, chattering during machining is prevented and stable machining is performed in gripping the thin-walled cylindrical work W such as the housing of a torque converter or a compressor. It can be carried out. Further, since the auxiliary cylinder 28 is arranged in the chuck body 2 so that the plunger 25 of the auxiliary cylinder 28 moves in parallel with the rotation axis C, the auxiliary cylinder 28 is arranged along the radial direction as in the conventional case. In comparison, the outer dimensions can be reduced. Further, the plunger 25 of the auxiliary cylinder 28 cannot move in the radial direction, and the centrifugal force acting on the plunger 25 does not affect the gripping force of the auxiliary pawl 38. Therefore, the centrifugal force acting on the plunger 25 is prevented. The chuck 1 that can keep the gripping force of the auxiliary pawl 38 constant even if the rotation speed changes by merely adjusting the balance of the centrifugal force acting around the support pin 37 of the auxiliary pawl 38 without consideration.
Can be provided. Further, by exchanging the balance weight 40 together with the auxiliary soft jaw 39 when the work W is set up, the balance of the centrifugal force acting around the support pin 37 of the auxiliary jaw 38 can be easily adjusted. Further, since the auxiliary cylinder 28 is an annular cylinder composed of the ring member 21, the support member 23, and the plunger 25, a plurality of auxiliary cylinders are provided as in the conventional case, and a large number of insertions for these auxiliary cylinders are provided. Since it is not necessary to form a hole or a fluid passage, the processing cost can be suppressed.

Although the auxiliary cylinder 28 is constructed as one annular cylinder in the above embodiment, a plurality of auxiliary claws 3 are provided.
8 may be provided with a plurality of auxiliary cylinders 28, and the plungers 25 of these auxiliary cylinders 28 may move in parallel with the rotation axis C. Further, in the above-described embodiment, the cam lever mechanism is used as a mechanism for changing the forward / backward movement of the draw bar 12 into the swing of the main pawl 6 in the radial direction, but a wedge mechanism may be used. Further, in the above embodiment, the main claw 6 is configured to swing in the radial direction, but may be configured to move in parallel in the radial direction. Further, the main claw 6 may be configured as a collet chuck or a finger chuck.

Next, an embodiment of the chuck of the present application will be summarized. (a) A draw bar that swingably supports the middle part of the main claw 6 on the chuck body 2 with the support pin 5, and moves the anti-holding end of the main claw 6 back and forth in the chuck body 2 by the action of the rotating cylinder. 12 and engages the intermediate portion of the auxiliary pawl 38 with the support pin 37.
Is swingably supported by the chuck body 2, and the anti-grasping end of the auxiliary claw 38 is supported by the plunger 25 of the auxiliary cylinder 28.
The chuck according to claim 1, wherein the chuck is pivotally attached to the tip. (b) The auxiliary pawl 38 is configured such that, when the chuck is rotated, the masses of the front side portion and the rear side portion divided about the support pin 37 are substantially the same value. Chuck. (c) The chuck according to claim 1, wherein the auxiliary claw 38 balances the moment acting around the support pin 37 during chuck rotation. (d) The annular ring member 21, the support member 23, and the plunger 25 constitute an auxiliary cylinder 28.
The spring 27 for moving the plunger 25 in the releasing direction is interposed between the support member 23 and the support member 23.
The described chuck. (Effect) Only one fluid supply path for moving the plunger in the gripping direction needs to be provided in the drawbar, which simplifies the configuration.

[0013]

As described above, according to the first aspect of the present invention, the auxiliary cylinder is arranged so that its plunger moves in parallel to the rotation axis of the chuck, so that the outer dimension can be reduced. Further, according to claim 2, the intermediate portion of the auxiliary claw is swingably supported by the chuck body by the support pin, and the anti-grasping end of the auxiliary claw is pivotally attached to the plunger of the auxiliary cylinder to rotate the auxiliary claw by chuck rotation. At this time, since the centrifugal force acting on the front portion and the rear portion divided around the support pin is configured to be substantially the same, even if the peripheral speed is constant processed and the rotation speed fluctuates during the processing. The holding force of the auxiliary claw can be kept constant, and stable processing can be performed. Further, in claim 3, since the auxiliary claw is configured by detachably mounting the auxiliary soft claw and the balance weight on the auxiliary claw main body, the auxiliary claw can be replaced with the auxiliary soft claw at the time of the work change of the work. The balance around the support pin can be easily adjusted. Further, in claim 4, since the auxiliary cylinder is constituted by one annular cylinder, the processing cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a front view of a chuck of this embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a vertical sectional view of a conventional chuck.

[Explanation of symbols]

1 chuck, 2 chuck body, 6 main jaws, 2
8 auxiliary cylinders, 37 support pins, 38 auxiliary claws,
39 auxiliary soft nails, 40 balance weights

Claims (4)

[Claims] 1. A plurality of main claws for holding and releasing a work by the action of a rotating cylinder, and a plurality of auxiliary claws for additionally holding a work held by the main claw by the action of an auxiliary cylinder provided in a chuck body. In a chuck comprising and
A chuck, wherein the auxiliary cylinder is arranged so that its plunger moves parallel to the axis of rotation of the chuck. 2. An intermediate portion of the auxiliary claw is swingably supported by a chuck pin on a chuck body, and an anti-grip end of the auxiliary claw is pivotally attached to a plunger of an auxiliary cylinder so that the auxiliary claw is rotated when the chuck rotates. 2. The chuck according to claim 1, wherein the centrifugal force acting on the front portion and the rear portion divided about the support pin is substantially the same. 3. The chuck according to claim 2, wherein the auxiliary claw is configured by detachably mounting an auxiliary soft claw and a balance weight on a main body of the auxiliary claw. 4. The chuck according to claim 1, wherein the auxiliary cylinder is composed of one annular cylinder.