JP6654405B2 - Chuck device - Google Patents

Description

  The present invention relates to a chuck device for a machine tool for gripping a workpiece with a jaw.

When a workpiece is machined by a machine tool, the workpiece is gripped by an openable jaw by a chuck device attached to a main shaft such as a lathe.
In general, various technologies are known for the chuck device mounted on a machine tool, such as a technology for increasing the gripping force and a technology for increasing the opening / closing stroke of the jaw, under the constraint of making the chuck device as compact as possible according to the user's request. I have. As a technique for increasing the gripping force, for example, there is a technique disclosed in Patent Document 1 (FIG. 1). In Patent Document 1 (FIG. 1), the wedge plunger 6 and the master jaw 4 slide on the wedge portion, and the gripping force is increased by reducing the inclination angle of the wedge portion with respect to the rotation axis.

  On the other hand, as a technique for increasing the opening / closing stroke of the jaw, there is a technique disclosed in Patent Document 2, for example. In Patent Literature 2, by having the link mechanism 40, the axial movement stroke of the draw bar 20 is directly converted to the radial movement of the clamp claw 50. That is, it is possible to easily secure a large opening / closing stroke of the clamp claw with respect to the movement stroke of the drawbar.

JP-A-10-86005 (FIG. 1) JP 2014-140935 A

  In the technique of providing a wedge mechanism as disclosed in Patent Document 1, in order to increase the gripping force, it is better to reduce the inclination angle of the wedge with respect to the rotation axis. However, the smaller the inclination angle, the smaller the opening / closing stroke amount of the jaw. On the other hand, if the opening / closing stroke of the jaw is increased with the same gripping force (inclination angle), the chuck device itself becomes large.

  In the technique of providing a link mechanism as disclosed in Patent Document 2, it is possible to increase the opening / closing stroke of the jaw of the chuck. is there.

  That is, in the conventional compact chuck device, it is difficult to increase the gripping force and increase the opening / closing stroke of the jaw.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a compact chuck device which has a high gripping force and can increase a jaw opening / closing stroke amount.

The chuck device of the present invention includes a chuck body provided with a jaw guide groove at one end side, a master jaw slidable in the chuck radial direction engaged with the jaw guide groove, and a top jaw fastened to the master jaw. A plunger slidable in the chuck axis direction within the chuck body, the plunger having a bush hole engaging with the bush and performing a first wedge action , and being provided on the inward side of the other end of the chuck body. The bush has a biasing means for biasing the bush, the engagement surface between the bush and the bush hole of the plunger has an inclination angle θ1 with respect to the chuck axis, and the rear end of the master jaw has a projection having a T-shaped section. The bush has, at one end, a recess having a T-shaped cross section that engages with the projection of the master jaw and performs a second wedge action, and the engagement surface between the projection and the recess of the bush is positioned with respect to the chuck axis. Tilt Has an angular .theta.2, inclination angle θ1 is characterized by a larger configuration the inclination angle .theta.2.
According to the above configuration, the opening and closing stroke of the jaw can be increased due to the relationship between the first wedge action and the inclination angle θ1. Further, the gripping force can be increased based on the relationship between the second wedge action, the urging means, and the inclination angle θ2.
A second invention is characterized in that the biasing means is a leaf spring provided on an inner side of a rear end of the chuck body.
According to the above configuration, although a large force is required for the deformation, a strong urging force can be generated.
A third invention is characterized in that the bush is capable of reversing the direction of inclination formed with the chuck axis.
According to the above configuration, it is possible to grasp the inner diameter of the work.

  ADVANTAGE OF THE INVENTION According to this invention, in a compact chuck | zipper apparatus, a gripping force is high and the opening / closing stroke of a jaw can be enlarged.

FIG. 3 is a sectional view of a chuck according to the present invention. FIG. 3 is an exploded perspective view of the chuck device. FIG. 3 is an exploded perspective view of a master jaw, a bush, and a plunger of the chuck device of FIG. 2. It is a perspective view of a master jaw. FIG. 7 is a partial cross-sectional view illustrating an operation state of the chuck device and illustrating a state where a workpiece is not gripped. FIG. 7 is a partial cross-sectional view illustrating an operation state of the chuck device and illustrating a state at a moment when a work and a top jaw come into contact with each other. FIG. 7 is a partial cross-sectional view illustrating an operation state of the chuck device and illustrating a state where a work is gripped.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings as appropriate. It should be noted that the following description of the preferred embodiment is merely an example in nature, and is not intended to limit the present invention, its application, or its use.

(Embodiment)
An embodiment according to the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view of a chuck according to the present invention, FIG. 2 is an exploded perspective view of a chuck device, and FIG. 3 is a bush which is a component part of a master jaw and a wedge action for causing the master jaw to perform a gripping operation. FIG. 4 is an exploded perspective view of the plunger and a plunger.

  As shown in FIGS. 1 to 3, the chuck body 10 has a housing portion 11 and a lid portion 12, and the housing portion 11 and the lid portion 12 are fixed by bolts B1. A jaw guide groove 15 having a T-shaped cross section is provided in the front plate 13 of the housing portion 11, and a master jaw 50 is slidably engaged with the jaw guide groove 15 in the chuck radial direction. . On the other hand, a plunger 20 is provided in the cylindrical portion 14 of the housing portion 11 so as to be slidable in the chuck axis J direction.

The housing portion 11 is provided with a cover 80 for preventing chips from entering the chuck body 10 from the front plate portion 13 side inward, and the cover 80 is fixed with bolts B4.
A top jaw 60 is fixed to a front surface of the master jaw 50 with a bolt B5.
The housing 11, the lid 12, and the plunger 20 supported in the housing 11 of the chuck body 10 are integrally fixed to a spindle (not shown) of the lathe by, for example, six bolts B <b> 2. I have.

A drawbar connecting portion 30 is fixed to the plunger rear portion 21 of the plunger 20 with bolts B3, and the drawbar connecting portion 30 is connected to a drawbar driven by, for example, a cylinder (not shown), similarly to a conventionally known chuck.
The plunger 20 is provided with a bush hole 22 which is one of the main components of the first wedge action, and this bush hole 22 penetrates outward at an inclination angle θ1 with respect to the chuck axis J. Have been. In the present embodiment, the inclination angle θ1 is set to 40 degrees.

The bush 40 is housed in the aforementioned bush hole 22 in engagement with the master jaw 50. The bush 40 is slidable in the bush hole 22, and the outer periphery of the bush 40 has a sliding surface 43. The bush 40 is accommodated at an inclination angle θ1 (40 degrees) with respect to the chuck axis, similarly to the through hole of the bush hole 22.
The bush 40 is a substantially columnar member, and is provided with a concave portion 41 having a T-shaped cross section on a front surface that engages with the master jaw 50. The recess 41 is provided with an engagement surface 42 that engages with an engagement surface 54 of the master jaw 50 described below.
On the other hand, the bush 40 has a contact surface 44 on the rear surface, and the contact surface 44 is in contact with a leaf spring 70 which is an urging means described later. That is, the bush 40 is provided so as to be supported by the bush hole 22, the leaf spring 70, and the master jaw 50.

The lid 12 is provided with a groove 16 in which the leaf spring 70 is stored.
One end of the leaf spring 70 is housed in the groove 16 of the lid 12, and the other end is in contact with the bush 40. By using the leaf spring 70, a large force is required for deformation, but a strong urging force can be generated. That is, the urging means that is not easily deformed is selected.

As shown in FIG. 4, the master jaw 50 is provided with a protruding portion 51 inward and rearward. The projecting portion 51 generates a second wedge action when engaged with the recess 41 having a T-shaped cross section of the bush 40, and a reinforcing portion 53 which is orthogonal to the wedge portion 52 and mechanically reinforces the wedge portion 52. Is formed in a T-shape. An engagement surface 54 that engages with the recess 41 of the bush 40 is provided on the upper end surface of the wedge portion 52.
The mating surface 42 of the bush 40 and the mating surface 54 of the master jaw 50 are each formed at an inclination angle θ2 outward with respect to the chuck axis J. In the present embodiment, the inclination angle θ2 is set to 15 degrees.

The operation will be described below with reference to FIGS.
FIG. 5 illustrates the operation state of the chuck device of FIG. 1, in which the workpiece is not gripped, FIG. 6 shows the state at the moment when the workpiece comes into contact with the top jaw, and FIG. 7 shows the state in which the workpiece is gripped. Is shown.
In the following, the left side of the drawing is defined as the rear, the right side as the front, and the lower side of the drawing as the radial direction, the left direction as the rear direction, the right direction as the front direction, and the lower direction as the radial direction. .
The work gripping operation of the chuck device 1 is performed, for example, according to the flow from FIG. 5, FIG. 6, and FIG. Actually, gripping is instantaneously performed by a series of operations.

  In the chuck device 1 of the present embodiment, when the drawbar is pulled rearward by a thrust Q from a cylinder (not shown) in the state of FIG. 5, the drawbar connection portion 30 connected to the drawbar is fastened to the drawbar connection portion 30 with bolts B3. The plunger 20 moves backward. At this time, a force P1 is generated on the sliding surface 43 of the bush 40 sliding in the bush hole 22 of the plunger 20 by the first wedge action. The force P1 is converted from the direction of the chuck axis J to the force F1 in the radial direction, so that the bush 40 moves in the radial direction.

Here, the front of the master jaw 50 is engaged with the jaw guide groove 15 formed in the chuck body 10, while the rear protruding portion 51 is engaged with the concave portion 41 of the bush 40.
That is, when the bush 40 moves in the radial direction, the master jaw 50 engaged with the concave portion 41 of the bush 40 also moves in the radial direction along the jaw guide groove 15 formed in the chuck body 10.
Further, in front of the master jaw 50, a top jaw 60 for gripping the work W is fastened by bolts B5 and moves until it comes into contact with the work W.
The bush 40 has an angle of inclination θ1 with respect to the chuck axis J, and the larger the angle, the larger the opening / closing stroke of the topshow 60.

Next, the moment when the top jaw 60 contacts the workpiece W will be described with reference to FIG.
As shown in FIG. 6, as compared with FIG. 5, when the drawbar pulls the drawbar connecting portion 30 backward, the plunger 20 moves backward, and the bush 40, the master jaw 50, and the top jaw 60 move in the radial direction. I have.
In this state, when the force P1 continues to act on the bush 40, the contact surface 44 of the bush 40 presses the leaf spring 70 backward. Accordingly, the leaf spring 70 is elastically deformed, and the drawbar connecting portion 30, the plunger 20, and the bush 40 move rearward by the amount of the deformation. FIG. 7 shows the state at this time.

  As shown in FIG. 7, the master jaw 50 cannot move in the radial direction because the top jaw 60 grips the workpiece W, but the bush 40 moves backward by the amount of deformation of the leaf spring 70, and furthermore, Since it also moves in the radial direction, the engagement surface 42 of the bush 40 and the engagement surface 54 of the master jaw 50 slide, and the second wedge action occurs. Each of the mating surfaces of the bush 40 and the master jaw 50 has an inclination angle θ2 with respect to the chuck axis. By reducing the angle of θ2, the force P2 in the chuck axis J direction is reduced in the radial direction. Force F2 is greatly increased. Then, the force F2 becomes the gripping force F3 via the master jaw 50 and the top jaw 60, and the gripping force of the work W can be increased.

As described above, according to the chuck device 1 of the first embodiment, in the compact chuck device, the top jaw 60 is formed by increasing the inclination angle θ1 of the bush 40, which is a main member of the first wedge action, as much as possible. The opening and closing stroke of the top jaw 60 can be increased by minimizing the inclination angle θ2 of the respective mating surfaces 42 and 54 of the bush 40 and the master jaw 50 which are the main members of the second wedge action. Work gripping force can be increased.
Further, by making the inclination angle θ1 larger than the inclination angle θ2, a compact chuck device 1 can be provided.

  That is, the compact chuck device 1 has a high gripping force for the work and can increase the opening / closing stroke amount of the top jaw 60, so that the chuck device 1 with high versatility and a wide allowable range of the diameter and the weight of the work that can be gripped is provided. can do.

(Other embodiments)
As described above, the embodiment has been described. However, the present invention may be appropriately changed without departing from the scope of the object, and is not limited to this embodiment.
For example, in the present embodiment, the inclination angles θ1 and θ2 are set to 40 degrees and 15 degrees, respectively, but can be changed as appropriate according to the size of the inch size of the chuck.
In the present embodiment, the leaf spring 70 is used. However, the present invention is not limited to the leaf spring, and a large force is required to deform the member. However, any member that generates a strong urging force may be used. Or a disc spring.
Although the outer periphery of the plunger 20 of the present embodiment is circular, any shape may be used as long as a part of the outer periphery of the plunger 20 is supported by the cylindrical portion forming the chuck body 10, such as a rice ball shape or a circular shape. The shape may be such that a part of the portion is lightened.
In addition, the bush 40 and the bush hole 22 for accommodating the bush 40 are formed at an inclination angle θ1 outward with respect to the chuck axis J direction. However, the present invention is not limited to this, and the inclination direction formed by the chuck axis is reversed. It does not matter.

As described above, according to the other embodiments, the weight of the chuck device can be reduced by reducing the thickness of the plunger 20.
In addition, by reversing the inclination direction, it becomes possible to grasp the inner diameter of the work.

  As described above, the chuck device according to the present invention can be mounted on, for example, a lathe machine, which grips and turns a workpiece, and can grasp a large-diameter workpiece and grip a workpiece with a high gripping force. .

Reference Signs List 1 chuck device 10 chuck body 15 jaw guide groove 20 plunger 40 bush 41 concave portion 50 master jaw 51 projecting portion 60 top jaw 70 leaf spring θ1, θ2 tilt angle J chuck axis

Claims (3)

A chuck body having a jaw guide groove on one end side, a master jaw engaged with the jaw guide groove and slidable in the chuck radial direction, a top jaw fastened to the master jaw, and a chuck in the chuck body. A plunger slidable in the axial direction, comprising:
The plunger has a bush hole that engages with the bush and performs a first wedge action.
An urging means for urging the bush toward the inside of the other end of the chuck body,
An engagement surface between the bush and the bush hole of the plunger has an inclination angle θ1 with respect to a chuck axis,
The rear end of the master jaw has a T-shaped cross section,
The bush has a concave portion having a T-shaped cross section that engages with the protrusion of the master jaw and performs a second wedge action on one end side,
An engagement surface between the projection and the recess of the bush has an inclination angle θ2 with respect to a chuck axis,
The chuck device according to claim 1, wherein the inclination angle θ1 is larger than the inclination angle θ2.
  2. The chuck device according to claim 1, wherein the urging unit is a leaf spring provided on an inner side of a rear end of the chuck body.   The chuck device according to any one of claims 1 to 2, wherein the bush is capable of reversing a tilt direction formed with a chuck axis.

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