JPH0118249Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a face clamp chuck for a machine tool that grips a workpiece by bringing a plurality of gripping claws into contact with the end face of the workpiece.

(Prior Art) Conventionally, a face clamp chuck used in a machine tool such as a lathe generally has three claws that are brought into contact with the end face of the workpiece to grip the workpiece.

However, with such conventional face clamp chucks, for example, when gripping an irregularly shaped workpiece whose end face is not flat and whose thickness is uneven, each claw is used to hold the workpiece. Due to variations in the end face, each part may come into contact with parts of different heights, and in such a case, the force with which each claw presses the end face of the workpiece will be different, so the three claws will have to hold the workpiece evenly. There was a problem in that the workpiece could not be gripped reliably with force, and the workpiece could shift or come off during processing.

In addition, as a means of solving these problems, a means for absorbing variations in the workpiece by holding each pawl via a spring for a fixed amount of movement of a transmission member that is formed integrally with the drive shaft is used. It was difficult to store this inside the chuck body due to space limitations, and there was a problem in that it was not possible to absorb variations in the workpiece.

(Problems to be solved by the invention) The present invention was developed by focusing on these conventional problems, and it is possible to reliably grip even irregularly shaped workpieces with high and low end faces with uniform force. The object of the present invention is to provide a face clamp chuck which can be used as a three-jaw or four-jaw clamp by replacing the gripping jaws at the tip depending on the type of workpiece.

(Means for solving the problem) The gist of the present invention to achieve this purpose is as follows:
In a face clamp chuck that grips a workpiece by bringing a plurality of gripping claws provided on a chuck body attached to the spindle end of the machine tool into contact with the end face of the workpiece, the chuck moves forward and backward by a drive source behind the spindle of the machine tool to A drive shaft inserted into the spindle, and a central portion that is held between the drive shaft via a spherical washer by the head of a screw connected to the drive shaft and is swingable within a plane that includes the spindle axis. a transmission member having spherical engaging portions formed at both ends thereof, and a through hole formed in the center to slidably engage the engaging portions at both ends of the transmission member, and cutout grooves at both ends. a pair of engaging members having an arcuate protrusion on the back surface of the groove, and a small diameter portion at the rear that can be engaged with the engaging portions at both ends of the engaging member, and a gripping claw extending in the radial direction at the tip. It consists of a claw holding shaft that is provided and has a guide groove on the outer periphery of the side surface and is slidably inserted into the chuck body, and a guide rod that is provided on the outer periphery of the chuck body to engage with the guide groove of the claw holding shaft. A face clamp chuck characterized in that it grips evenly without being affected by changes in the contact surface of the gripping claws.

(Function) And, in the above face clamp chuck,
The axial displacement of the drive shaft is transmitted to the four pawl holding shafts via the transmission member and each of the engaging members, so that each pawl holding shaft slides, and each of the engaging members is movable around the engaging portion with the transmission member, and the transmission member is pivoted to the drive shaft at its center, so the four pawl holding shafts can be slid independently. It's summery.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

1 to 4 show an embodiment of the present invention.

As shown in FIG. 1, a chuck body 32 of a face clamp chuck 2 is fixed to a spindle 1 of a lathe via an adapter 31.

As shown in FIGS. 1 to 3, a workpiece mounting member 33 serving as a workpiece mounting portion is fastened to the center of the front end surface 32a of the chuck body 32 with a bolt B3.

A tapered hole 33a is bored in this workpiece mounting member 33, and a positioning pin 33c is protruded from the front end surface 33b.

The workpiece pallet 34 mounted on the workpiece mounting member 33 is provided with a protruding taper shank 34a that fits into the tapered hole 33a, and a positioning hole 34c that engages with the positioning pin 33c. By engaging the positioning hole 34c with the positioning pin 33c, the workpiece W fixed to the workpiece pallet 34 is held in a correct posture.

Of course, the spindle 1 of the lathe is configured to be indexed to a fixed angular position by a servo motor or the like.

On the circumferential portion 32b of the chuck body 32, four pawl holding shafts 41 to 44 are respectively arranged at four substantially symmetrical locations with respect to the center of rotation. Each claw holding shaft 41 to 44 is connected to the front end surface 3 of the chuck body 32.
2a, and gripping claws 51-54 are removably fastened to the tips of the respective claw holding shafts 41-44 by bolts B4. Further, each of the claw holding shafts 41 to 44 is positioned at a feeding position (a first
It is supported by the chuck body 32 so as to be able to slide and turn in the axial direction between the position shown in the figure) and the retracted position where the contact surfaces of the gripping claws 51 to 54 contact the end surface W1 of the workpiece W.

The rear end of each claw holding shaft 41 to 44 has a circumferential portion 32b.
protrudes into the inside of the chuck body 32 from the inner end surface 32c, and the rear end thereof has circumferential grooves 41a to 41a.
44a is formed.

As shown in FIGS. 1 and 2, spiral grooves 41b to 44b are provided on the sides of each claw holding shaft 41 to 44, and engagement pins P1 to 44b that engage with the spiral grooves 41b to 44b are provided. P4 is removably screwed onto the chuck body 32.

The shape of each spiral groove 41b to 44b is such that when each claw holding shaft 41 to 44 is in the extended position,
As shown by the chain line in the figure, each gripping claw 5
1 to 54, and when each claw holding shaft 41 to 44 is displaced from the extended position to the retracted position, each gripping claw 51 to 54 is moved from the retracted position to the second position.
It is designed to be turned clockwise to the right in the figure to displace it to the protruding position shown by the solid line in the figure.

As shown in FIG. 4, each gripping claw 51 to 54 is removed and a cover 5 is attached to the tip of each claw holding shaft 41 to 44.
0 can be attached with a bolt B4, and in the extended position, the distance from the end surface 50a of the cover 50 to the front end surface 32a of the chuck body 32 is equal to the contact surface 51a of each gripping claw 51 to 54.
~ 54a to the front end surface 32a of the chuck body 32
is equal to the interval between.

As shown in FIGS. 1 and 3, the first engaging member 61 engages with two adjacent claw holding shafts 41 and 44 of the four claw holding shafts 41 to 44 so as to be able to transmit motion. At the same time, the remaining two claw holding shafts 4
2 and 43, a second engaging member 62 arranged in parallel with the first engaging member 61 engages with the second engaging member 62 so as to be able to transmit motion.

A claw holding shaft 4 is provided at both ends of the first engaging member 61.
Semicircular engagement grooves 61a and 61b are formed to engage with the circumferential grooves 41a and 44a of 1 and 44,
Similarly, claw holding shafts 4 are provided at both ends of the second engaging member 62.
Semicircular engagement grooves 62a and 62b are formed to engage with the circumferential grooves 42a and 43a.
Each engaging member 61, 62 has each circumferential groove 41a to 44a.
As shown in FIG. 1, both ends of each of the engaging members 61 and 62 have axial play so that they can swing slightly in the direction of the arrow in FIG. The claw holding shafts 41 to 44a are engaged with the circumferential grooves 41a to 44a, and each claw holding shaft 41 to 44a is engaged with the circumferential grooves 41a to 44a.
An arcuate engaging portion 61c is formed in point contact with the engaging surfaces 41c to 44c of 44.

As shown in Figures 3 and 4, the first and second
Through holes 61d and 62d are formed in the center portions of the engaging members 61 and 62, and extend in a direction perpendicular to the axial direction and perpendicular to the longitudinal direction of the engaging members 61 and 62, respectively.

As shown in FIGS. 1 to 3, each engaging member 6
1 and 62, each claw holding shaft 4
A spring 63 is provided that biases in a direction opposite to the retracting direction of 1 to 44.

As shown in FIG. 1, the through hole 10 extending in the axial direction in the spindle 1 and the through hole 31a of the adapter 31 are connected to a driving source (not shown), and are driven by the driving force from the driving source. A drive shaft 7 that moves in the axial direction is inserted therethrough.

This drive shaft 7 has a tip 71 that is inserted into both the through holes 10 and 31a, and a through hole 3 of the adapter 31.
1a, and a connecting bolt 73 that is fixed to the connecting member 72 and the shaft portion 73a with a set screw 72a and integrally engages with the drive shaft 7.
It is composed of.

As shown in FIGS. 1, 3, and 4, the axial movement of the drive shaft 7 is controlled by the first and second engaging members 6.
1 and 62 is interposed between the drive shaft 7 and the first and second engaging members 61 and 62.

A central portion 80 of the transmission member 8 is pivotally supported by an end portion of the drive shaft 7 via a washer 91 and a spherical seat 92, and both ends 81, 82 are connected to the first and second engaging members 61, 62 through holes 61d and 62d, respectively.

In this central portion 80, the shaft portion 7 of the connecting bolt 73 is provided.
A bottom portion 80b having an engagement hole 80a that loosely fits into 3a.
, washer 91, spherical seat 92 and connecting bolt 73
A storage recess 80c for the head 73b is formed. Upper end surface 80e and lower end surface 8 of peripheral wall portion 80d
0f is an inner wall protrusion 32 formed inside the chuck body 32 as shown in FIGS. 1 and 3.
It is in contact with the end surfaces 32f and 32g of d and 32e. The central bottom portion 80b of the transmission member is sandwiched between the connecting member 72 of the drive shaft 7 and the head 73b of the connecting bolt 73 via a washer 91 and a spherical seat 92. Therefore, the transmission member 8
Although it cannot rotate around the drive shaft 7 in the plane of the drawing, it can swing in the direction of the arrow around the engagement portion with the drive shaft 7 in the plane of the drawing of FIG.

As shown in FIGS. 3 and 4, the transmission member 8
Both ends 81 and 82 of the transmission member 8 are connected to the respective through holes 61d and 6 so that the transmission member 8 can swing in the direction of the arrow in the paper plane of FIG.
The contact surfaces are arcuate so as to make point contact with the inner periphery of 2d.

Face clamp chuck 2 having the above configuration
The case where the workpiece W is gripped by four gripping claws will be described below.

Each gripping claw 51~ is attached to the tip of each claw holding shaft 41~44.
54 with bolts B4, each claw holding shaft 4
1 to 44 are set at the feeding position (the position shown in FIG. 1), the tapered shank portion 34a of the workpiece pallet 34, on which the workpiece W has been assembled in advance, is fitted into the tapered hole 33a of the workpiece mounting member 33,
The work pallet 34 is attached to the work mounting member 33. At this time, the work W is held in the correct posture by engaging the positioning hole 34c with the positioning pin 33c.

In the state shown in FIG. 1, when the drive shaft 7 is moved to the left by a drive source (not shown), the connecting bolt 73 of the drive shaft 7 connects the spherical seat 92 and the washer 91.
The transmission member 8 connected to the drive shaft 7 moves to the left together with the drive shaft 7, with its center portion 80 being pivotally supported by the shaft portion 73a of the connection bolt 73.

Since both ends 81 and 82 of the transmission member 8 are engaged with the through holes 61d and 62d of the first and second engagement members 61 and 62, the first and second engagement members 61 and 62 are connected to the transmission member 8. is moved to the left in FIG.

The engagement grooves 61a and 61b of the first engagement member 61 engage with the circumferential grooves 41a and 44a of the claw holding shafts 41 and 44, and the engagement groove 6 of the second engagement member 62
2a and 62b are the circumferential grooves 42 of the claw holding shafts 42 and 43
a, 43a, each claw holding shaft 41
44 are moved leftward from the extended position shown in FIG. 1 to the retracted position by the first and second engaging members 61 and 62.

When each claw holding shaft 41 to 44 moves to the left in FIG. 1, the spiral groove 41b of each claw holding shaft 41 to 44
44b and the engagement pins P1 to P4, each of the gripping claws 51 to 54 rotates to the right from the retracted position shown by the chain line in FIG. 2 and moves to the position shown by the solid line. By further retracting each of the gripping claws 41 to 44 with each of the gripping claws 51 to 54 turned to the rotation position, the contact surfaces of each of the gripping claws 51 to 54 abut against the end surface W1 of the workpiece W. Particularly work W
is grasped.

Here, each of the engaging members 61 and 62 is able to swing in the direction of the arrow in FIG. Since each of the claw holding shafts 41 to 44 is movable in the direction of the arrow in FIG.
The same load is acting on the points .about.44.

Therefore, even if the contact surfaces of the gripping claws 51 to 54 contact different heights of the end surface W1 of the workpiece W, the gripping claws 51 to 54 can press the workpiece W with equal force. can.

Next, when moving each of the claw holding shafts 41 to 44 from the retracted position where each of the gripping claws 51 to 54 holds the workpiece W to the extended position shown in FIG. When moved to the right in FIG. 1, the transmission member 8 and the first and second engagement members 6
1 and 62, each of the claw holding shafts 41 to 44 is moved rightward toward the feeding position.

By this movement, each of the gripping claws 51 to 54 first separates from the end surface W1 of the workpiece W, and each of the gripping claws 51 to 5
4 moves from the protruding position to the retracted position at the second position.
Turn left as shown.

In this way, the workpiece pallet 34 can be removed from the workpiece mounting member 33 by a robot or the like in a state in which each of the claw holding shafts 41 to 44 has returned to the feeding position.

Further, when one of the four gripping claws is removed from the claw holding shaft and the workpiece W is to be gripped by the three grasping claws, for example, as shown in FIG. 4, the presser claw 54 is removed from the claw holding shaft 44, The remaining three gripping claws 51-5
3, a cover 50 is attached to the tip of the claw holding shaft 44.

In this attached state, the distance from the end surface 50a of the cover 50 in the extended position to the front end surface 32a of the chuck body 32 as shown in FIG. 32a, when each of the claw holding shafts 41 to 44 moves to the retracted position and the contact surfaces of each of the gripping claws 51 to 53 contact the end surface W1 of the workpiece W, the cover 50 end face 50a of
It is in contact with the front end surface 32a of the chuck body 32. Therefore, similarly to the case where the four gripping claws described above are used, the workpiece W is held by the three gripping claws 51 to 53.
gripped with uniform force.

In addition, in addition to the spiral grooves 41b to 44b, when the claw holding shafts 41 to 44 are displaced from the extended position to the retracted position in FIG.
54 from the retracted position to the left in a counterclockwise direction as shown in FIG.
4, and the engaging pins P1 to P4 may be selectively engaged with the spiral grooves 41b to 44b or the left-turning spiral groove depending on the shape of the workpiece W.

(Effect of the invention) According to the face clamp cap according to the invention, the transmission member that transmits the movement of the drive shaft in the axial direction to the four pawl holding shafts via the first and second engagement members is provided. , whose center part is pivotally supported by the end of the drive shaft, and the first and second engaging members are swingable around the engaging part with the transmission member, so the four claw holding shafts are It is possible to slide independently in the axial direction, and irregularly shaped workpieces with uneven thickness on the end faces can be
The two gripping claws allow for secure gripping with even force.
If necessary, one gripping claw can be removed and the workpiece can also be gripped by three gripping claws.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of the present invention, in which Figure 1 is a longitudinal sectional view, Figure 2 is a view taken in the direction of the arrows in Figure 1, and Figure 3 is a sectional view taken along the line 1. , FIG. 4 is a sectional view taken along the line -- in FIG. 3. DESCRIPTION OF SYMBOLS 1... Spindle, 2... Face clamp chuck, 7... Drive shaft, 8... Transmission member, 10...
...Through hole in spindle, 32...Chuck body, 32a...Front end surface of chuck body portion, 33
...Work mounting member (work mounting part), 41-4
4... Claw holding shaft, 51-54... Gripping claw, 61...
...First engaging member, 62... Second engaging member, 92...
...Spherical seat, W...Workpiece, W1...End face of workpiece.

Claims (1)

[Scope of Claim for Utility Model Registration] A face clamp chuck that grips a workpiece by bringing a plurality of gripping claws provided on a chuck body attached to the end of the spindle of a machine tool into contact with the end face of the workpiece, the drive behind the spindle of the machine tool; a drive shaft that is moved back and forth by a power source and inserted into the spindle; and a plane that includes the spindle axis and is held between the drive shaft by a head of a screw connected to the drive shaft via a spherical washer. a transmission member whose central portion is swingably supported within the transmission member and has spherical engaging portions formed at both ends; and a through hole drilled in the central portion that slidably engages with the engaging portions at both ends of the transmission member. and a pair of engaging members having cutout grooves formed at both ends and an arcuate protrusion on the back surface of the groove, and a small diameter portion that is engageable with the engaging portions at both ends of the engaging member formed at the rear, and a small diameter portion at the tip thereof. A claw holding shaft provided with a gripping claw extending in the radial direction and having a guide groove on the outer circumference of the side surface and slidably inserted into the chuck body; and a claw holding shaft provided on the outer circumference of the chuck body to engage with the guide groove of the claw holding shaft. A face clamp chuck consisting of a guide rod and a guide rod, which grips the workpiece evenly without being affected by changes in the contact surface of the gripping claws.