JP7308528B2 - Chuck device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck device used in a lathe or the like, and more particularly to a mounting structure for gripping claws for gripping a work.

2. Description of the Related Art Various chuck devices are used to hold a work in a lathe or the like. For example, Patent Literatures 1 to 3 describe devices in which gripping claws provided on the front portion of a chuck body are moved in the radial direction to grip the outer circumference or the inner circumference of a workpiece with the gripping claws.

A draw bar is provided concentrically with the axis of the chuck body so as to be able to advance and retreat in the axial direction. Further, the chuck body is formed with the same number of holes inclined with respect to the axis as the gripping claws, and shaft-like chucking pins can slide in the inclined holes. A top jaw (gripping claw) is provided at the front end of the chucking pin. The drawbar and chucking pin are connected via an actuator.

When the drawbar retreats in the axial direction with respect to the chuck body, the chucking pin is pulled rearward via the actuator. In the case of a chuck device that grips the outer periphery of a work, pulling the chucking pin backward causes the top jaw to move radially inward to grip the outer periphery of the work, thereby gripping the work concentrically with the axis. At that time, the rear surface of the work is brought into close contact with the stopper provided on the chuck body, so that the correct gripping posture is maintained.

JP 2008-221365 A Japanese Patent Application Laid-Open No. 2002-103109 JP 2012-218117 A

According to the conventional chucking device, when trying to grip different types and sizes of workpieces, it becomes necessary to replace the top jaw fixed to the chucking pin with another one. When replacing the top jaw, loosen the fixing bolt and remove the already attached top jaw from the chucking pin, then attach another top jaw to the tip of the chucking pin and fix it by tightening the fixing bolt. becomes.

However, the attachment and detachment of the top jaw involves tightening and loosening of the fixing bolt with respect to the chucking pin, so a tool is required. It is desirable that the attachment and detachment of the top jaw be as easy as possible. In this respect, according to the chuck device of Patent Document 3, the top jaw is small, so it is somewhat easy to attach and detach. It is the same as 1 and 2, and is similar in that various top jaws must be prepared.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to easily cope with works of different types and sizes.

In order to solve the above problems, the present invention provides a plurality of chucking pins arranged around the axis of a chuck body, top jaws provided on the chucking pins, auxiliary claws for gripping a workpiece, and the chuck. A first member having a first tapered portion that is inclined with respect to a plane perpendicular to the axial direction of the main body, a second member having a second tapered portion that is in sliding contact with the first tapered portion, and a radial direction of the chuck body. and a screw shaft disposed along the first member and the The second member is relatively moved in the axial direction of the chuck body to press the end surface of the auxiliary claw toward the facing surface of the top jaw, thereby fixing the auxiliary claw to the top jaw. bottom.

Here, it is possible to employ a configuration in which the screw shaft is screwed via an operation portion provided radially outwardly of the chuck body.

In each of these aspects, the first member includes a base portion attached to the front surface of the top jaw, arm portions extending rearward from both ends of the base portion in the width direction, and the top jaw provided at the rear end of the arm portion. and a locking portion attached to the rear surface of the housing.

In addition, the auxiliary claws include: a base portion attached to the facing surface of the top jaw; arm portions extending rearward from both ends of the base portion in the width direction; It is possible to employ a configuration including a locking portion to which the lock is applied.

According to the present invention, it becomes possible to easily deal with works of different types and sizes.

1 is a vertical sectional view showing one embodiment of the present invention; Right side view of Fig. 1 Cross-sectional view showing a fixing structure between the top jaw and the auxiliary claw Right side view of Fig. 3 Plan view of FIG. Bottom view of Figure 3 Perspective view of FIG. FIG. 2 is an exploded perspective view showing a fixing structure between top jaws and auxiliary claws; FIG. 2 is an exploded perspective view showing a fixing structure between top jaws and auxiliary claws; FIG. 2 is an exploded perspective view showing a fixing structure between top jaws and auxiliary claws;

An embodiment of the invention will be described based on the drawings. In this embodiment, while pulling the workpiece w rearward in the axial direction with the top jaw 20, the surface facing the rear end side of the workpiece w is brought into contact with the stoppers 5 and 6, and in this state, the auxiliary jaw 20 is attached to the top jaw 20. It is a retractable chuck device 50 that grips a workpiece w concentrically with the axis of a chuck body 1 with claws (gripping claws) 30 .

As shown in FIG. 1, the chuck body 1 is constructed by connecting a rear plate and a front plate with bolts. An actuator 4 that advances and retreats along the axis of the chuck body 1 is provided in the space between the rear plate and the front plate. The actuator 4 has a plurality of inclined holes 2 equally spaced around the axis. In this embodiment, three oblique holes 2 are provided. Each inclined hole 2 extends in a direction in which the center of the hole is inclined with respect to the axis of the chuck body 1 . In this embodiment, the slanted hole 2 is slanted from the rear toward the front in the axial direction of the chuck body 1 gradually toward the outer diameter side. Depending on the setting, the direction may be reversed, that is, the chuck body 1 may be inclined toward the inner diameter side gradually from the rear toward the front.

The inclined holes 2 are formed in the same number as the top jaws 20 to be installed, and in each of the inclined holes 2, a shaft-shaped chucking pin 10 is tightly fitted as an operating means. The chucking pin 10 and the inclined hole 2 are relatively movable along the direction in which the inclined hole 2 extends. The rear end 12 of the chucking pin 10 and the actuator 4 are connected so as to move integrally in the axial direction of the chuck body 1 .

A top jaw 20 is provided at the front end of each chucking pin 10 . Therefore, as shown in FIG. 2, the same number of top jaws 20 as the chucking pins 10 are radially provided around the axis of the chuck body 1 in equally divided directions. In this embodiment, three top jaws 20 are provided. In this embodiment, the chucking pin 10 has a circular cross section, and the inclined hole 2 also has a circular cross section. relative movement is performed. Reference numeral 7 in the drawing denotes a pin, and reference numeral 14 denotes a groove into which the pin 7 is inserted. The rotation of the chucking pin 10 is prevented by sliding the pin 7 within the groove 14 .

A jaw (recess) 13 is provided at the front end of the chucking pin 10 . An inner diameter surface 13 b of the jaw portion 13 is inclined in a direction toward the axial center of the chuck body 1 as it goes forward in the axial direction of the chuck body 1 . Moreover, the inner diameter surface 13b is a cylindrical surface or a conical surface having an arc shape in a side view shown in FIG. The top jaw 20 is fixed to the chucking pin 10 such that the outer diameter surface 21b of the top jaw 20 abuts against the inner diameter surface 13b of the jaw portion 13 in surface contact. Here, the top jaw 20 has an outer diameter surface 21 b that is in surface contact with the inner diameter surface 13 b of the jaw portion 13 . The outer diameter surface 21b is a cylindrical surface in surface contact with the inner diameter surface 13b of the jaw 13 when it is a cylindrical surface, and a conical surface in surface contact with it when it is a conical surface.

The chucking pin 10 and the top jaw 20 are fixed by screwing a screw 22 into a screw insertion hole 23 provided in the main body portion 21 of the top jaw 20 and a screw hole 15 provided in the chucking pin 10, so that both are fixed. It is fixed by being tightened in the axial direction of the chuck body 1 . At this time, the rear end surface 21 a of the top jaw 20 comes into surface contact with the inner end surface 13 a of the jaw portion 13 . As a result, in a longitudinal section including the axis, the contact surface between the inner diameter surface 13b and the outer diameter surface 21b, which intersect each other at an acute angle, and the contact surface between the inner end surface 13a and the rear end surface 21a. , the chucking pin 10 and the top jaw 20 are held. A ridge portion between the outer diameter surface 21b and the rear end surface 21a forms a relief portion 21c that does not come into contact with the jaw portion 13 of the chucking pin 10. As shown in FIG.

The top jaw 20 has an auxiliary claw 30 that abuts on the workpiece w at its inner diameter side end. The auxiliary claws 30 come into contact with the outer surface of the work w to grip the work w.

A jaw (recess) 25 is provided at the front end of the top jaw 20 . An inner diameter surface 21 e of the jaw portion 25 is inclined in a direction toward the axial center of the chuck body 1 as it goes forward in the axial direction of the chuck body 1 . In addition, the inner diameter surface 21e is a cylindrical surface or a conical surface having an arc shape when viewed from the side. The auxiliary claw 30 is fixed to the top jaw 20 in such a manner that the outer diameter surface 31b of the auxiliary claw 30 is in surface contact with the inner diameter surface 21e of the jaw 25 . Here, the auxiliary claw 30 has an outer diameter surface 31 b that comes into surface contact with the inner diameter surface 21 e of the jaw portion 25 . The outer diameter surface 31b is a cylindrical surface in surface contact with the inner diameter surface 21e of the jaw 25 when it is a cylindrical surface, and a conical surface in surface contact with it when it is a conical surface.

Fixing between the top jaw 20 and the auxiliary claw 30 is performed by a fixing means 40 . At this time, the rear end surface 31a of the auxiliary claw 30 comes into surface contact with the facing surface 21d of the jaw portion 25. As shown in FIG. As a result, two contact surfaces, namely, the contact surface between the inner diameter surface 21e and the outer diameter surface 31b that intersect each other at an acute angle in the longitudinal section including the axis and the contact surface between the opposing surface 21d and the rear side end surface 31a, A top jaw 20 and an auxiliary claw 30 are held. A ridgeline portion between the outer diameter surface 31b and the rear side end surface 31a serves as a relief portion 31c that does not come into contact with the jaw portion 25 of the top jaw 20. As shown in FIG.

In this embodiment, a drawbar 3 is used as a means for operating the actuator 4 . The drawbar 3 and the actuator 4 are bolted together or molded as an integral member. Therefore, if the drawbar 3 moves forward in the axial direction of the chuck body 1, the actuator 4 also moves forward in the axial direction of the chuck body 1, and if the drawbar 3 moves backward in the axial direction of the chuck body 1, The actuator 4 also moves rearward in the axial direction of the chuck body 1 . The chucking pin 10 slightly advances and retreats within the inclined hole 2 by advancing and retreating the actuator 4 in the axial direction. Due to this movement, the front end of the chucking pin 10 moves in the radial direction of the chuck body 1 , and the top jaw 20 and the auxiliary jaws 30 also move in the radial direction of the chuck body 1 along with the movement. As a result, the auxiliary claws 30 can grip the outer surface of the work w and release the grip.

The fixing means 40 can detachably fix the auxiliary claw 30 to the top jaw 20 . As described above, when assembling the retractable chuck device 50 , the auxiliary jaws 30 corresponding to the workpiece w to be gripped are fixed to the top jaw 20 . Also, when trying to grip a work w of a different kind or size, the auxiliary claw 30 fixed to the top jaw 20 is replaced with another one. Attachment and detachment of these auxiliary claws 30 are performed by fixing means 40 .

The fixing means 40 includes a first member 41 having a first tapered portion 41a that is inclined with respect to a plane orthogonal to the axial direction of the chuck body 1 (hereinafter referred to as a plane orthogonal to the axis), and a first tapered portion 41a. A second member 42 having a second tapered portion 42a in sliding contact therewith, and a screw shaft 43 arranged along the radial direction of the chuck body 1 are provided.

As shown in FIGS. 3 to 8, the first member 41 has a screw 22 screwed into a screw insertion hole 23 provided in the top jaw 20 and a screw hole 21h provided in the chucking pin 10, thereby It is fixed by being tightened in the axial direction of the chuck body 1 . As shown in FIG. 8, the first member 41 includes a base portion 41i attached to the front surface 21i of the top jaw 20, an arm portion 41f extending rearward from both ends of the base portion 41i in the width direction, and a rear end of the arm portion 41f. and a locking portion 41g that is attached to the rear surface 21a of the top jaw 20. As shown in FIG. The inner side surface 41j of the arm portion 41f is in close contact with the side surface 21j of the top jaw 20, and the front surface 41k of the locking portion 41g is in close contact with the rear surface 21a of the top jaw 20, thereby achieving axial positioning. The outer diameter surface 41b of the base portion 41i abuts against the inner diameter surface 21f of the projecting portion 21g provided on the top jaw 20, thereby positioning the chuck body 1 in the radial direction. The outer diameter surface 41b and the inner diameter surface 21f are cylindrical surfaces or conical surfaces that are in surface contact with each other.

The first member 41 has a hole portion 41m that opens on the inner diameter side. The first member 41 also has a screw hole 41n extending from the outer diameter surface 41b to the hole portion 41m. The inner wall of the hole portion 41m on the front side in the axial direction of the chuck body 1 is a first tapered portion 41a. In this embodiment, the first tapered portion 41a is a slanted surface that faces rearward in the axial direction of the chuck body 1 with respect to the axial orthogonal surface as it goes to the outer diameter side. The inner wall of the chuck body 1 on the rear side in the axial direction of the hole portion 41m forms a rear side inner surface 41e parallel to the plane perpendicular to the axis. The rear inner surface 41e reaches the bottom surface 41c of the hole 41m.

The second member 42 is a block-shaped piece member that is inserted into the hole 41 m of the first member 41 . As shown in FIGS. 8 and 9, the second member 42 includes a second tapered portion 42a that is in surface contact with the first tapered portion 41a of the first member 41 while being inserted into the hole portion 41m, and a first member A top surface 42c in surface contact with the bottom surface 41c of the first member 41 and a rear end surface 42f in surface contact with the rear inner surface 41e of the first member 41 are provided. In this embodiment, like the first tapered portion 41a, the second tapered portion 42a is a slanted surface that is inclined rearward in the axial direction of the chuck body 1 with respect to the axial orthogonal surface toward the outer diameter side. Further, the second member 42 has a pressing portion 42b protruding slightly rearward from the rear end face 42f, closer to the inner diameter than the rear end face 42f. A top surface 42c of the second member 42 is provided with a locking slit 42d having an inverted T-shaped cross section. The locking slit 42d opens toward the second tapered portion 42a and closes without opening toward the rear end surface 42f. The locking slit 42d has a narrow portion 42e with a narrow width on the side close to the top surface 42c and an enlarged portion 42g with a wide width on the side far from the top surface 42c. 42h.

As shown in FIGS. 8 and 9, the screw shaft 43 includes an operating portion 43c provided radially outwardly of the chuck body 1, a screw portion 43b screwed into the screw hole 41n of the first member 41, and the chuck body 1. and a convex portion 43a having a larger diameter than the shaft portion 43d provided at the tip of the shaft portion 43d.

As shown in FIG. 9, the screw shaft 43 and the second member 42 are engaged by inserting the convex portion 43a of the screw shaft 43 into the enlarged portion 42g and the shaft portion 43d into the narrow portion 42e. Then, the radially outer end of the screw portion 43b of the screw shaft 43 is screwed into the radially inner opening of the screw hole 41n (opening on the hole portion 41m side). The screwing can be performed by inserting a tool through the radially outer opening of the screw hole 41n and inserting the tip of the tool into the operation portion 43c. In this embodiment, the operating portion 43c of the screw shaft 43 is a concave portion (in this embodiment, a hexagonal concave portion in plan view) formed in the shaft end surface, and the outer diameter of the operating portion 43c is larger than the outer diameter of the screw portion 43b. Since the diameter is not large, such an operation is possible. As in this embodiment, by making the screw shaft 43 a so-called hollow set (set screw) type, the operation portion 43c can be inserted into the screw hole 41n. As long as the screw shaft 43 has a sufficient length for engagement with the second member 42, the screw portion 43b is screwed into the screw hole 41n from the radially outer opening of the screw hole 41n. can also be done. If the outer diameter of the operating portion 43c is larger than the outer diameter of the screw portion 43b like a normal bolt having a bolt head, such a mode can be adopted.

By screwing the screw shaft 43, the second member 42 is drawn toward the bottom surface 41c of the hole 41m of the first member 41, that is, toward the chuck body 1 radially outward. As a result, the first tapered portion 41 a and the second tapered portion 42 a slide in the radial direction of the chuck body 1 , and the first member 41 and the second member 42 move relative to each other in the axial direction of the chuck body 1 . Here, the first tapered portion 41 a and the second tapered portion 42 a are inclined axially rearward as they go radially outward of the chuck body 1 . The chuck body 1 is pressed axially rearward. Then, the pressing portion 42b of the second member 42 presses the facing surface 31e of the auxiliary claw 30 rearward in the axial direction of the chuck body 1. As shown in FIG. As a result, the end surface 31 a of the auxiliary claw 30 is pressed toward the facing surface 21 d of the top jaw 20 , and the auxiliary claw 30 is fixed to the top jaw 20 .

Here, as shown in FIG. 8, the auxiliary claw 30 includes a base portion 31i applied to the facing surface 21d of the top jaw 20, an arm portion 31f extending rearward from both ends of the base portion 31i in the width direction, and a rear arm portion 31f. An engaging portion 31g is provided at the end and is attached to the back surface 21a of the top jaw 20. As shown in FIG. The inner side surface 31j of the arm portion 31f is in close contact with the side surface 21k of the top jaw 20, and the front surface 31k of the engaging portion 31g is in close contact with the rear surface 21a of the top jaw 20, thereby achieving axial positioning. Further, the upper surface 31m of the arm portion 31F is brought into close contact with the side stepped portion 21m of the top jaw 20 by tightening by the fixing means 40, thereby positioning the chuck body 1 in the radial direction. At this time, as described above, surface contact between the facing surface 21d of the jaw portion 25 of the top jaw 20 and the rear side end surface 31a of the auxiliary claw 30, and the inner diameter surface 21e of the jaw portion 25 of the top jaw 20 and the auxiliary claw 30 Positioning in two directions is also accomplished by surface contact with the outer diameter surface 31b of the .

In this invention, as fixing means 40 for detachably fixing the top jaw 20 and the auxiliary claw 30, a first member 41 having a first tapered portion 41a inclined with respect to a plane perpendicular to the axial direction of the chuck body 1 is provided. , a second member 42 having a second tapered portion 42a that slides on the first tapered portion 41a, and a screw shaft 43 arranged along the radial direction of the chuck body 1. By screwing the screw shaft 43, the first By sliding the tapered portion 41 a and the second tapered portion 42 a in the radial direction of the chuck body 1 , the first member 41 and the second member 42 are moved relative to each other in the axial direction of the chuck body 1 to form the auxiliary claw. The auxiliary claw 30 is fixed to the top jaw 20 by pressing the end surface 31a of the top jaw 20 toward the facing surface 21d of the top jaw 20.例文帳に追加As a result, the auxiliary jaws 30 can be easily attached to and detached from the top jaw 20 by operating the screw shaft 43 directed in the radial direction of the chuck body 1. As a result, workpieces w of different types and sizes can be easily attached and detached. Thus, the chuck device 50 that can easily cope with

Further, if the screw shaft 43 is screwed through the operation portion 43c provided radially outwardly of the chuck body 1, the operation can be performed in a wide space outside the chuck body 1. , the attachment and detachment operation is easier.

In this embodiment, the outer periphery of the work w is gripped by the auxiliary claws 30, but as a modified example, the present invention can also be applied to the case of gripping the inner periphery of the work w by the auxiliary claws 30. When the inner periphery of the workpiece w is gripped, the center of the inclined hole 2 for accommodating the chucking pin 10 of the chuck body 1 is gradually inclined toward the inner diameter side from the rear to the front of the chuck body 1. . Further, the auxiliary claws 30 are arranged radially outward of the chuck body 1 . Furthermore, in this embodiment, the chucking pin 10 and the top jaw 20 are configured as separate members. can.

1 Chuck main body 10 Chucking pin 20 Top jaw 21a Rear surface 21d Opposing surface 21i Front surface 30 Auxiliary claw 31a End surface 31f Arm portion 31g Locking portion 40 Fixing means 41 First member 41a First taper portion 41f Arm portion 41g Locking portion 41i Base portion 42 Second member 42a Second tapered portion 43 Screw shaft 50 Chuck device

Claims (4)

a plurality of chucking pins (10) arranged around the axis of the chuck body (1);
a top jaw (20) provided at the front end of the chucking pin (10);
an auxiliary claw (30) for gripping the work (w);
a first member (41) having a first tapered portion (41a) inclined with respect to a plane perpendicular to the axial direction of the chuck body (1);
a second member (42) having a second tapered portion (42a) in sliding contact with the first tapered portion (41a);
a screw shaft (43) arranged along the radial direction of the chuck body (1);
with
The top jaw (20) has a jaw (25) having a facing surface (21d) facing forward in the axial direction and an inner diameter surface (21e) extending forward from the outer diameter side end of the facing surface (21d). the inner diameter surface (21e) is inclined toward the axial center of the chuck body (1) toward the front in the axial direction,
By screwing the screw shaft (43) , the second member (42) moves radially outward relative to the first member (41), whereby the first taper portion (41a) and the second taper portion (41a) are formed. (42a) slides to move the second member (42) axially rearward relative to the first member (41) , thereby moving the rear end surface (31a) of the auxiliary claw (30). ) is pressed against the facing surface (21d) of the top jaw (20), and the outer diameter surface (31b) of the auxiliary claw (30) is brought into contact with the inner diameter surface (21e) of the jaw (25). A chuck device for fixing the auxiliary claw (30) to the top jaw (20). 2. The chuck device according to claim 1, wherein the screw shaft (43) is screwed through an operation portion (43c) provided radially outwardly of the chuck body (1). The first member (41) is
a base (41i) applied to the front surface (21i) of the top jaw (20);
arm portions (41f) extending rearward from both ends in the width direction of the base portion (41i);
a locking portion (41g) provided at the rear end of the arm portion (41f) and applied to the rear surface (21a) of the top jaw (20);
The chuck device according to claim 1 or 2, comprising: The auxiliary claw (30)
a base (31i) applied to the facing surface (21d) of the top jaw (20);
arm portions (31f) extending rearward from both ends in the width direction of the base portion (31i);
a locking portion (31g) provided at the rear end of the arm portion (31f) and applied to the rear surface (21a) of the top jaw (20);
The chuck device according to any one of claims 1 to 3, comprising:

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