JP2019034384A - Chuck device - Google Patents

Abstract

To provide a chuck device capable of restraining deformation of a work without enlarging a top jaw with a simple structure.SOLUTION: In a chuck device having a jaw for grasping a work by sliding in the radial direction, the jaw comprises a master jaw and a top jaw installed in the master jaw, the top jaw is composed of a first top jaw and a second top jaw, and the master jaw comprises a linkage part linking with the second top jaw on the front side opposed to the second top jaw, the first top jaw is fixed to the master jaw, and comprises a grasping part on the front side and the opposed side of the second top jaw, and the second top jaw comprises an engaging part engaging with the linkage part on the back side, a fulcrum shaft supported by a chuck body and capable of rocking the second top jaw in the radial direction and an action part grasping the work on the front side and the opposite side of the first top jaw.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a chuck device that grasps a workpiece (work) during machining with a lathe or the like, and particularly relates to a technique that can suppress deformation of the workpiece during grasping.

  When performing machining such as turning while rotating the workpiece with a lathe or the like, it is necessary to firmly grasp the workpiece. Generally, a chuck is used as an apparatus for grasping such a workpiece.

  In order to grasp the workpiece, a plurality of jaws that slide in the radial direction are arranged radially on the front side in the axial direction of the chuck. The jaw includes a master jaw that is provided in the chuck body and slides in the radial direction, and a top jaw that is detachably attached to the master jaw with a bolt or the like and grasps the workpiece.

  In recent years, there has been an increasing demand for weight reduction of parts such as automobiles, and parts are becoming thinner. With conventional chucks, the outer diameter or inner diameter of a workpiece is grasped by a top jaw in the conventional chuck, but if the grasping force is increased, the deformation of the workpiece increases due to the thin wall. , Which leads to poor processing accuracy.

  For example, in the case of a 3-jaw chuck having three jaws, there are three points per workpiece, and the workpiece is deformed into a rice ball shape. If the workpiece is processed in such a state and the grasp of the workpiece is released, the workpiece is in a reverse rice ball shape as far as possible.

  Patent Document 1 is one of the prior arts aimed at solving such problems.

  In the top jaw shown in FIG. 5 of Patent Document 1, in order to suppress the deformation of the workpiece, the top jaw is formed in a wide shape in the circumferential direction so as to come into contact with the workpiece at two positions.

By doing so, when the workpiece is grasped with three claws, the entire circumference of the workpiece is grasped at six positions, and deformation of the workpiece can be suppressed.

JP2013-233598A

  However, in the top jaw shape of the chuck shown in FIG. 5 of Patent Document 1, the jaw becomes large and the weight increases, so that the rotation speed of the chuck cannot be increased. In addition, the structure of the jaw itself is complicated, for example, the jaw has an equalize structure in order to make each contact portion uniform.

Accordingly, an object of the present invention is to provide a chuck device having a simple structure and capable of suppressing deformation of a workpiece without increasing the size of a top jaw.

  The present invention relates to a chuck device that has a jaw on the front side of a chuck body that slides in a radial direction and grasps a workpiece such that the center of the workpiece coincides with a rotation axis.

  The jaw includes a master jaw assembled to the chuck body and a top jaw that is detachably attached to the master jaw and grasps the workpiece.

  The top jaw includes a first top jaw and a second top jaw installed with a certain gap in the radial direction.

  The master jaw has a linkage portion linked to the second top jaw on the front side facing the second top jaw.

  The first top jaw is fixed to the master jaw and has a grasping portion on the front side and on the opposite side of the second top jaw.

  The second top jaw includes an engaging portion that engages with the linkage portion on the back side, a fulcrum shaft that is supported by the chuck body and that allows the second top jaw to swing in the radial direction, the front side, and the first top jaw. And an action part for grasping the workpiece on the opposite side of the.

Then, as the master jaw moves in the radial direction, the second top jaw swings and approaches or separates from the first top jaw, thereby grasping or releasing grasping of both surfaces of the workpiece by the grasping portion and the action portion. It is configured as follows.

According to the chuck device of the present invention, the deformation of the workpiece can be suppressed with a simple structure and without increasing the size of the top jaw.

It is sectional drawing which showed typically the structure of the jaw of the chuck apparatus of this embodiment. It is sectional drawing which showed typically the workpiece | work grasping operation | movement of FIG. It is a front view of the chuck device of this embodiment. It is the schematic sectional drawing which showed typically the structure of the jaw of the chuck | zipper apparatus in the modification 1 of this invention. It is the schematic sectional drawing which showed typically the structure of the jaw of the chuck | zipper apparatus in the modification 2 of this invention. It is the schematic sectional drawing which showed typically the structure of the jaw of the chuck | zipper apparatus in the modification 3 of this invention. It is the schematic sectional drawing which showed typically the structure of the jaw of the chuck | zipper apparatus in the modification 4 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. Moreover, it can change suitably in the range which does not deviate from the range which has the effect of this invention. In the description, unless otherwise stated, the direction X parallel to the rotation axis J of the chuck body is defined as the “axial direction”, the side for grasping the workpiece (front side in the axial direction) is “front”, and the opposite side. The (rear side in the axial direction) is the “rear surface”. Further, the radial direction Y around the rotation axis J of the chuck body is defined as “radial direction”, the central side is “inward”, and the opposite side is “outward”. Further, when the chuck body is viewed from the front, a direction Z parallel to the radial direction (horizontal axis) obtained by rotating the radial direction Y (vertical axis) about the rotation axis J by 90 degrees is defined as a “circumferential direction”.

  FIG. 1 is a cross-sectional view schematically showing a configuration of a jaw of a chuck device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the workpiece grasping state of FIG. FIG. 3 is a front view of the chuck device according to the embodiment of the present invention.

<Basic configuration of chuck>
As shown in FIGS. 1 and 3, the chuck device 10 includes a chuck body 20 having a thick disk-like appearance. The chuck body 20 is used with its back surface fixed to a machine tool such as a lathe so that its front surface is orthogonal to the rotation axis J.

  The front surface of the chuck body 20 is a flat surface, and a circular opening 21 is formed at the center thereof. On the front surface of the chuck body 20, a plurality of jaws 30 (three or more in the present embodiment, which may be at least two in this embodiment) are radially arranged at equal intervals.

Each jaw 30 is detachably attached to the front surface of the master jaw 40 slidably assembled to the chuck body 20 in the radial direction, and the top jaw 50 grasps the workpiece (work w). Are installed.
In the case of the chuck device 10 according to the present embodiment, when turning is performed by a lathe or the like, each master jaw 40 slides inward in the radial direction, so that the workpiece w disposed at the center portion on the front surface of the chuck body 20. Is firmly grasped by the top jaw 50. Then, processing such as cutting is performed while rotating the workpiece.

(Master Joe 40)
On the front surface of the chuck body 20, three slide grooves 22 are formed radially outward from the periphery of the opening 21, and the master jaw 40 is a component constituting the chuck body 20, and these slide grooves 22 are formed. Are assembled in each of the.

  Each master jaw 40 is made of a metal member having a substantially T-shaped cross section, and each slide groove 22 has a substantially inverted T-shaped cross section corresponding to the master jaw 40. The contact surface 41 and the linking part 42 are fitted in the slide groove 22 so as to extend in the radial direction with the front surface of the chuck body 20 exposed.

  Although not shown, the chuck body 20 has a built-in plunger that slides in the axial direction, and each master jaw 40 slides along the radial direction in conjunction with the sliding of the plunger.

  The abutted surface 41 is a flat surface orthogonal to an axis parallel to the rotation axis J, and the abutted surface 41 is provided with a serration 41a. The serration 41a has a known serrated meshing structure, and is composed of a group of linear convex portions and linear concave portions that are substantially triangular concave and convex portions having a continuous cross-sectional shape. The serrated surface 41a is formed on the contacted surface 41 in parallel with the width direction (the direction on the short side) of the contacted surface 41 so as to extend in the circumferential direction.

  The contacted surface 41 is formed with one fastening hole 41b extending in parallel with the axial direction.

  On the other hand, the linking part 42 is a linking concave part 42 a provided with a certain clearance from the abutted surface 41 in the radial direction. The linkage recess 42a is formed at the center in the circumferential direction. Further, in this embodiment, the radial position (having a certain gap) is provided at a position of 3/4 inward in the radial direction, but can be appropriately changed depending on the size of the chuck device and the thickness of the workpiece. It is.

(Top jaw 50)
The top jaw 50 constitutes a portion of the jaw 30 that grasps the workpiece w. The top jaw 50 has various shapes depending on the shape and size of the workpiece. Although the position at which the top jaw 50 grasps the workpiece w also varies depending on the workpiece w and the grasping method thereof, the top jaw 50 of the present embodiment is constant in the radial direction between the first top jaw 51 and the first top jaw 51. And a second top jaw 52 having a gap.

(First top jaw 51)
The first top jaw 51 has a substantially rectangular parallelepiped shape, and a grasping portion 51 a is provided on the front side and the radially inward side (opposite side of the second top jaw 52).
On the front surface of the first top jaw 51, one bolt insertion hole 51b that extends through the first top jaw 51 in parallel with the axial direction is formed in accordance with the arrangement of the fastening holes 41b. The bolt insertion hole 51b includes a large-diameter head accommodating portion 51c that is located in the front and accommodates the head of the bolt B, and a small-diameter shaft accommodating portion 51d that is located in the back and accommodates the shaft portion of the bolt B. have.

  Moreover, the 1st top jaw 51 has the contact surface 51f which consists of a flat surface in which the serration 51e was formed in the back surface. The serration 51e is formed in parallel with the width direction (the direction on the short side) so as to extend in the circumferential direction. The serration 51e is formed according to the serration 41a of the abutted surface 41, and is designed so as to mesh with each other and come into close contact with each other.

(2nd top jaw 52)
The second top jaw 52 has a lever shape, and is fixed to an engagement portion 52a that engages with the linkage portion 42 on the back surface and a bracket that will be described later at the center portion, and can swing the second top jaw 52 in the radial direction. A fulcrum shaft 52b and an action portion 52c for grasping the workpiece w are provided on the front side and the radially outer side (opposite side of the first top jaw). The axial position of the action portion 52c is provided so as to face the grasping portion 51a when grasping the workpiece w.

  The engaging part 52 a has an engaging convex part 52 e that engages with the connecting concave part 42 a of the master jaw 40. Further, a force point portion 52f that comes into contact with the link recess 42a when the master jaw 40 moves radially inward is provided on the radially outward side of the engaging convex portion 52e.

  A support hole 52d is penetrated in the central portion of the second top jaw 52 in the circumferential direction, and a fulcrum shaft 52b having the same diameter as the support hole 52d is fitted into the support hole 52d. Further, as shown in FIG. 2, the axial positions of the support hole 52d and the fulcrum shaft 52b are the center distance L1 of the support hole 52d and the force point portion 52f and the center distance L2 of the support hole 52d and the action portion 52c. It is provided at an intermediate position where they are equal.

  The second top jaw 52 is supported by a bracket 53, and the bracket 53 is fixed to the chuck body 20 with a bolt B1. That is, the second top jaw 52 is supported by the chuck body 20 via the bracket 53.

  The bracket 53 has a certain thickness as shown in FIG. 1, and has a fan-like shape that spreads radially outward in a front view as shown in FIG.

  At the center of the outer edge, a notch that opens radially outward, has the same width as the second top jaw 52 in the circumferential direction, and is continuously formed so as to penetrate in the axial direction 53a is provided.

  On the other hand, in the circumferential direction, a through-hole 53b is formed that has a substantially same diameter as the fulcrum shaft 52 that passes through the notch 53a.

  That is, the bracket 53 is fixed to the chuck body 20 by the bolt B1 in a state where the second top jaw 52 is covered by the notch 53a so as to be swingable in the radial direction.

  The fulcrum shaft 52b is inserted from the outside of the bracket 53 into the support hole 52d of the second top jaw 52 via the one through hole 53b, and further inserted into the other through hole 53b.

  And the movement of the fulcrum shaft 52b in the circumferential direction is fixed by fastening the fulcrum shaft 52b with a pair of left and right retaining pins P provided in both through holes 53b. As described above, the second top jaw 52 is supported by the chuck body 20 via the bracket 53, so that the second top jaw 52 can swing in the radial direction about the fulcrum shaft 52b.

  The engaging convex portion 52 e of the second top jaw 52 is engaged with the linkage concave portion 42 a of the master jaw 40.

  Thus, as the master jaw 40 moves in the radial direction, the second top jaw 52 swings about the fulcrum shaft 52b and approaches or separates from the first top jaw 51, thereby causing the grasping portion 51a and the action. The part 52c grasps or cancels grasping of both sides of the workpiece.

Hereinafter, the operation of grasping the workpiece w will be described with reference to FIG.
Due to the thrust of a plunger (not shown) that slides in the axial direction, each master jaw 40 slides inward in the radial direction in conjunction with the thrust. This linkage is a linkage using a known wedge structure or lever structure. By this slide, the grasping portion 51a of the first top jaw 51 fixed to the master jaw 40 with the bolt B moves inward in the radial direction and comes into contact with the workpiece w.

  At the same time, the linking recess 42 a of the master jaw 40 pushes the power point 52 f of the second top jaw 52. As a result, the second top jaw 52 rotates in the direction of arrow A about the fulcrum shaft 52b, and the action portion 52c comes into contact with the workpiece w.

  At this time, since the grasping part 51a and the action part 52c press the outer diameter and inner diameter of the work w, respectively, the work can be firmly held and fixed.

  The acting force of the master jaw 40 at this time is F, the force that the first top jaw 51 pushes the workpiece w is f1, the force that the second top jaw 52 receives from the master jaw 40 is f2, and the second top jaw 52 is the workpiece If the force pushing w is f3, then f1 = f2 = f3 = F / 2.

As a result, deformation of the workpiece w when grasped can be suppressed.
In addition, as described above, the shape of the master jaw 40 is partially changed and the top jaw is divided into the first and second top jaws without significantly changing the chuck body structure, so that the workpiece can be deformed relatively easily. Realizes a chuck that suppresses

  In addition, since the first top jaw 51 is disposed radially outward and the second top jaw 52 is disposed radially inward, the bracket 53 that supports the second top jaw 52 is disposed radially inward. At the same time as chip removal is improved, the size of the bracket 53 can be made compact, and as a result, the rotational inertia of the entire chuck device 10 can be suppressed.

<Modification 1>
In the above embodiment, the master jaw 40 moves inward in the radial direction by an axial slide of a plunger (not shown), thereby grasping the workpiece w by the first top jaw 51 and the second top jaw 52. .
The known movement of the master jaw 40 in the radial direction is that the plunger moves in the radial direction inward or radially outward as the plunger moves in the axial direction to either the front side or the back side. . Further, it can be designed to move freely either radially inward or radially outward depending on the angle of the wedge mechanism interlocked with the movement of the plunger or the lever mechanism.

  Therefore, in this modification 1, the movement of the above-mentioned plunger is omitted, and the configuration of the jaw when the master jaw 40 moves radially outward is disclosed.

FIG. 4 is a schematic cross-sectional view schematically showing the configuration of the jaw of the chuck device according to the first modification.
As shown in FIG. 4, the first top jaw 51 and the second top jaw 52 of FIG. 4 make the first top jaw 51 and the second top jaw 52 of FIG. 2 mirror images. Similarly, the configuration of the master jaw 40 corresponding to the first and second top jaws 51 and 52 is also mirror-image symmetric.

Hereinafter, the operation for grasping the workpiece w will be described.
Due to the thrust of a plunger (not shown) that slides in the axial direction, each master jaw 40 slides radially outward in conjunction with the thrust. By this slide, the grasping portion 51a of the first top jaw 51 fixed to the master jaw 40 with the bolt B moves radially outward and comes into contact with the workpiece w.

  At the same time, the linking recess 42 a of the master jaw 40 pushes the power point 52 f of the second top jaw 52. As a result, the second top jaw 52 rotates about the fulcrum shaft 52b in the direction of the arrow A ', and the action portion 52c contacts the workpiece w.

  At this time, the acting force of the master jaw 40 is F ′, the force that the first top jaw 51 pushes the workpiece w is f1 ′, the force that the second top jaw 52 receives from the master jaw 40 is f2 ′, and the second top jaw If the force by which 52 pushes the workpiece w is f3 ′, then f1 ′ = f2 ′ = f3 ′ = F ′ / 2.

  As described above, in the first modification, the bracket 53 is provided radially outward from the workpiece w. Thereby, the restrictions of the dimension or arrangement | positioning of a workpiece | work can be reduced.

<Modification 2>
In the above-described embodiment, the linkage portion 42 of the master jaw 40 is the linkage recess 42a, and the engagement portion 52a of the second top jaw 52 is the engagement projection 52e. The second top jaw 52 is rotated around 52b.

  In the second modification, a mode is disclosed in which the second top jaw 52 is rotated by having the linkage convex portion 42b in the linkage portion 42 and the engagement recess 52g in the engagement portion 52a.

FIG. 5 is a schematic cross-sectional view schematically showing the configuration of the jaw of the chuck device according to the second modification.
As shown in FIG. 5, the linkage portion 42 of the master jaw 40 includes a linkage projection 42 b and is formed at the center in the circumferential direction. On the other hand, the engaging portion 52 a of the second top jaw 52 corresponding to the linkage portion 42 includes an engagement recess 52 g, and the engagement recess 52 g is engaged with the linkage projection 42 b of the master jaw 40.

In the second modification, by providing the projection of the linkage convex portion 42b on the master jaw 40 side, the second top jaw 52 side has a high degree of freedom in arrangement radially inward or radially outward. A variety of workpiece diameters and shapes can be accommodated.
Further, the gripping portion 51a of the first top jaw 51 and the action portion 52c of the second top jaw 52 press the outer diameter and inner diameter of the workpiece w, thereby holding the workpiece firmly while suppressing deformation of the workpiece w. Can be fixed.

  Also in the second modification, the first top jaw 51 and the second top jaw 52 are mirror-symmetrical, and the configuration of the master jaw 40 corresponding to the first and second top jaws 51 and 52 is also mirror-symmetrical. Also good.

<Modification 3>
In the above-described embodiment, the gripping portion 51a of the first top jaw 51 and the action portion 52c of the second top jaw 52 press the outer diameter and inner diameter of the workpiece w, thereby holding and fixing the workpiece w while suppressing deformation. can do.

  In the third modification, a mode in which the pressing member 60 is used to hold and fix the workpiece w is disclosed.

FIG. 6 is a schematic cross-sectional view schematically showing the configuration of the jaw of the chuck device according to the third modification.
As shown in FIG. 6, the second top jaw 52 has an opening opening on the first top jaw 51 side in the action portion 52 c facing the grasping portion 51 a of the first top jaw 51, and on the inner peripheral surface thereof. A screw hole 52h in which a screw groove (female screw) is formed is provided. A pressing member 60 having a spherical shape, a substantially truncated cone shape, or a pin shape is screwed onto the screw hole 52h at the top of the head. The top member of the pressing member 60 is always urged toward the workpiece w by the spring in the pressing member.

In the third modification, a commercially available ball plunger is used as the pressing member 60. However, the present invention is not limited to this, and a pin plunger may be used as long as it is biased by a spring.
The pressing member 60 is not limited to the second top jaw 52 side, and may be provided on the grasping portion 51a of the first top jaw 51.

  According to the third modification, the ball plunger is provided on either the grasping portion 51a of the first top jaw or the action portion 52c of the second top jaw, thereby absorbing variations in the force that the ball plunger pushes with three claws. Thus, the deformation of the workpiece can be further suppressed.

<Modification 4>
In the above-described embodiment, the linkage portion 42 of the master jaw 40 is the linkage recess 42a, and the engagement portion 52a of the second top jaw 52 is the engagement projection 52e. The second top jaw 52 is rotated around 52b.

  In the fourth modification, a mode in which the second top jaw 52 is rotated by having the rack 42c in the linking part 42 and the pinion gear 52i in the engaging part 52a is disclosed.

FIG. 7 is a schematic cross-sectional view schematically showing the configuration of the jaw of the chuck device according to the fourth modification.
As shown in FIG. 7, the linkage portion 42 of the master jaw 40 has a rack 42 c on the front surface, and a pinion gear 52 i that meshes with the rack 42 c on the engagement portion 52 a.
That is, by the movement of the master jaw 40 in the radial direction, the second top jaw 52 including the pinion gear 52i meshed with the rack 42c can rotate around the fulcrum shaft 52b.

According to the fourth modification, the master jaw 40 and the second top jaw 52 can be formed at low cost.
Further, the gripping portion 51a of the first top jaw 51 and the action portion 52c of the second top jaw 52 press the outer diameter and inner diameter of the workpiece w, thereby holding the workpiece firmly while suppressing deformation of the workpiece w. Can be fixed.

As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible. In the above embodiment, it is suitable to grasp the thin cylindrical workpiece w, but it may be thick, and the cross section may be a square or a rectangle such as a rectangle or a polygon.
Further, the master jaw 40 and the first top jaw 51 are fixed directly by bolts. However, the present invention is not limited to this, and similarly to the jaw structure in a known chuck, a T groove is provided on the master jaw 40 side. By storing the T nut in the T groove, the first top jaw 51 may be positioned and fixed to the master jaw 40 via the T nut.
The positioning of the master jaw 40 and the first top jaw 51 is not limited to the serrations 41a and 51e, and a method using a key, a positioning pin, or the like may be used.

10 chuck device 20 chuck body 30 jaw 40 master jaw 42 linkage portion 42a linkage recess 42b linkage projection 42c rack 50 top jaw 51 first top jaw 51a grasping portion 52 second top jaw 52a engagement portion 52b fulcrum shaft 52c action portion 52e Engaging convex part 52g Engaging concave part 52i Pinion gear J Rotating shaft w Workpiece

Claims (4)

A chuck device having a jaw on the front side of the chuck body that slides in a radial direction to grasp the workpiece so that the center of the workpiece coincides with the rotation axis,
The jaw is
A master jaw assembled to the chuck body;
A top jaw that is detachably attached to the master jaw and grasps the workpiece;
Have
The top jaw includes a first top jaw and a second top jaw having a certain gap in the radial direction from the first top jaw,
The master jaw has a linkage portion linked to the second top jaw on the front side facing the second top jaw,
The first top jaw is fixed to the master jaw, and has a grasping portion on the front side and on the opposite side of the second top jaw,
The second top jaw has an engaging portion that engages with the linkage portion on the back side;
A fulcrum shaft supported by the chuck body and capable of swinging the second top jaw in a radial direction;
An action part for grasping the workpiece on the front side and the opposite side of the first top jaw;
Have
As the master jaw moves in the radial direction, the second top jaw swings and approaches or separates from the first top jaw, so that the grasping portion and the action portion grasp both surfaces of the workpiece. A chuck device that releases the grip. The linkage portion and the engagement portion are a linkage recess and an engagement projection, respectively, or
The chuck device according to claim 1, wherein the linkage portion and the engagement portion are a linkage projection and an engagement recess, respectively. The linkage part has a rack on the front side,
The chuck device according to claim 1, wherein the engagement portion includes a pinion gear that meshes with the rack.   The said 1st top jaw or the said 2nd top jaw has an opening part opened to the said holding | grip part or the said action part, respectively, and has a pressing member in this opening part. The chuck apparatus as described in any one.

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