JPH04223812A - Chuck device for thread groove phase matching - Google Patents

Abstract

PURPOSE:To provide a chuck for thread groove phase matching capable of fixing a lathe dog at a correct position, which is free from deformation due to gripping of a workpiece and free from phase slippage even when rotational force is exerted on the workpiece through tightening of a fixing bolt. CONSTITUTION:A gripping member 37 for gripping an outside circumferential surface of a workpiece W having a machined thread groove and supported by a center 4 is formed of an elastic member whose one end is fixed to an interior surface of a rotatable ring-shape chuck body 28 formed to insert the workpiece W into a rotation center and the other end, as a free end to be displaced only in the radial direction of the chuck body 28, is brought into abutting on the outside circumferential surface of the workpiece W. A pressing member 34 for pressing the free end of the gripping member 37 to the outside surface of the workpiece W is provided movably in the radial direction of the chuck body 28 inside the chuck body 28.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck device for adjusting the phase of a thread groove, for example, for accurately aligning the phase of the thread groove in advance when the thread groove formed by cutting is ground by a grinder.

0002

2. Description of the Related Art In order to grind with high precision the thread grooves of a screw shaft whose outer surface has been previously machined with thread grooves, it is necessary to accurately apply the grinding wheel of a grinding machine to the thread grooves. Therefore, conventionally, the phase of the thread groove N with respect to the cutting drive pin of the grinding machine is adjusted in advance using a thread groove phasing device 1 as shown in FIG. 4, for example. In the figure, W is a screw shaft as a workpiece, and a screw groove N is previously formed by cutting. One end of the workpiece W is supported by one center 2, and the other end is supported by the center 4 of the tailstock 3. A turner 5 is inserted into the outer periphery of the end of the workpiece W on the center 2 side, but its fixing bolt 5a is loosened. Then, the outer periphery of the end of the workpiece W on the center 2 side is gripped by rubber rollers 11a and 11b, which are gripping members of the chuck device 10 for thread groove phase alignment shown in FIG. Rotation is stopped at the position where the ball 7a is fitted into the thread groove N, and the burr 5 is fixed to the workpiece W by tightening the burr fixing bolt 5a. After that, work W is moved to both centers 2 and 4.
It is set between both centers of a thread grinding machine, and is automatically ground with the correct phase based on the burr 5 fixed as described above. During the grinding, the next workpiece W is set in the thread groove phasing device 1, gripped by the thread groove phasing chuck device 7 in the same manner as described above, and rotated to perform phasing. In this way, by setting the burr 5 in the correct phase for each work to be ground, highly accurate grinding becomes possible. If the phase is incorrect, the grinding wheel will not evenly hit the surface of the thread groove N, and the groove machining accuracy will quickly deteriorate.

In the conventional chuck device 10 for adjusting the phase of thread grooves, a pair of rubber rollers 11a and 11b as gripping members that rotate while gripping the outer peripheral surface of the end of the workpiece W can be opened and closed about a fulcrum 12. It is supported by arms 13a and 13b. The side surface of one arm 13a is locked to a rod 14a of an air cylinder 14, and the rod 14a
Both rubber rollers 11a and 11b grip the workpiece W by the elongation. These rubber rollers 11a, 11b are each rotationally driven via a toothed belt 16 by a motor 15, which is a rotating device. Note that 17 is a pulley.

0004

[Problems to be Solved by the Invention] However, in the conventional chuck device 10 for thread groove phasing,
Since the gripping members for the workpiece W are the rubber rollers 11a and 11b, when the workpiece W is gripped, they are compressed by the elasticity of the rubber and the outer diameter of the rollers changes. Therefore, even if the stepping motor 15 is used as a rotation device and the rotation is controlled by the number of pulses and the phase of the screw groove N is adjusted, there is a problem that the rotation angle of the workpiece W is different and control becomes difficult.

[0005] Also, in order to fix the cut 5, a fixing bolt 5 is used.
When tightening a, the center of the bolt tip does not necessarily hit perpendicularly to the outer peripheral surface of the workpiece W, resulting in uneven contact. If the tip of the fixing bolt 5a touches one side, the work W
A rotational force acts on the However, the gripping members of the conventional chuck device 10 for thread groove phase alignment are elastic rubber rollers 11a and 11b, which cannot resist the rotational force caused by tightening the fixing bolt 5a, so that the workpiece W rotates. As a result, the burr 5 and thread groove N were carefully matched.
There was a problem in that the phase between the two was shifted.

[0006] Chucks for machine tools include commonly used 3-jaw and 4-jaw jaw chucks and collet chucks, but jaw chucks have jaws that move in the radial direction of the chuck body. There is some play between the jaws and the chuck body. Therefore, when a rotational force is applied to the workpiece W, the jaws will be displaced in the circumferential direction by the amount of play, making it unsuitable as a chuck for phase alignment of thread grooves. Also, since the collet chuck has a fixed gripping diameter, it only needs to be a workpiece with a fixed outer diameter.
It cannot be applied when the outer diameter of the workpiece changes.

[0007] The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to be able to handle workpieces of various sizes and to prevent the workpiece from deforming even when gripped. Another object of the present invention is to provide a chuck device for thread groove phasing that can fix burrs at correct positions without causing phase shift even when rotational force is applied to a workpiece by tightening a fixing bolt.

[0008]

[Means for Solving the Problems] The present invention grips the outer peripheral surface of a workpiece having a thread groove on the outer surface and is supported between both centers with a gripping member, and rotates the workpiece with a rotation device to form a thread groove on the workpiece. A chuck device for thread groove phasing is provided with a ring-shaped chuck body formed so that a workpiece supported at the center is inserted into the center of rotation, and the gripping member is attached to the chuck body. One end is fixed to the inner surface and the other end is a free end that is displaced only in the radial direction of the chuck body and is made of an elastic member that comes into contact with the outer peripheral surface of the workpiece, and the free end of the gripping member is pressed from the back surface. The chuck body is characterized in that the member is disposed inside the chuck body so as to be movable in the radial direction of the chuck body.

[0009]

[Operation] When chucking a workpiece with a chuck device for thread groove phasing, the end face of the workpiece is rotatably supported at the center between both centers of the thread groove phasing device, and then the thread groove phasing is adjusted to one end of the workpiece. The chuck device is sent and set, and the free end of the gripping member is brought into contact with the outer circumferential surface of the end of the workpiece in the tangential direction. Since the gripping member is made of an elastic member and is movable in the radial direction of the chuck body, it can easily accommodate workpieces of various sizes with different outer diameters. Next, the pressing member is advanced from the retracted position in the radial direction of the chuck body, and is brought into contact with the back surface of the gripping member, thereby pressing the gripping member against the outer peripheral surface of the workpiece. At this time, the plurality of pressing members advance radially at the same time and press the outer surface of the cylindrical workpiece with opposing equal forces, so that the workpiece can be accurately centered. The thus gripped workpiece is rotated and phased using a positioning jig, but the gripping member has high rigidity and does not deform like a rubber roller. Therefore, the rotation angle of the workpiece and the rotation angle of the chuck body accurately match,
Rotation control using a stepping motor is easy.

[0010]Furthermore, in order to fix the chipping 5, a fixing bolt 5 is provided.
When tightening a, even if rotational force is applied to the workpiece, one end of the gripping member is fixed to the inner surface of the chuck body, and displacement of the chuck body in the circumferential direction is completely regulated. It can resist the rotational force caused by tightening the fixing bolt 5a and prevents the workpiece from rotating. therefore,
As in the past, the workpiece rotates relative to the gripping member,
There is no possibility that the phase between the burr and the thread groove will be out of phase, allowing accurate positioning.

[0011] Although the pressing member is designed to move in the radial direction of the chuck body, even if there is play between the pressing member and the chuck body, the workpiece is pressed through the gripping member. The rotational force acting on the workpiece will not cause it to shift in the circumferential direction by the amount of play.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 are views showing an embodiment of a chuck device for adjusting the thread groove phase of the present invention. The thread groove phasing chuck device 20 is mounted on the tailstock 3 of the thread groove phasing device. That is, in this embodiment, a slide unit 21 that can move back and forth in the axial direction is attached to the tailstock 3 via a bracket 21a with a screw B1, and a bracket 22 is attached to this slide unit 21 with a bolt B2.
A flange 23 of a chuck device 20 for thread groove phasing is supported on this bracket 22 by bolts B3. The center of this flange 23 is open,
The center 4 of the tailstock 3 protrudes from the opening. A case 24 of the thread groove phase matching chuck device 20 is attached to the front side of the flange 23. This case 2
A stepping motor 25 constituting a rotating device is attached to the upper rear surface of the motor 4 with bolts B4, and a motor pulley 26 is attached to its main shaft 25a. on the other hand,
A ring-shaped cylinder pulley 28 serving as a chuck body is disposed on the lower front side of the case 24 so as to be rotatable concentrically with the center 4 via a bearing 29 . 30
A and 30b are retaining rings that hold the bearing 29. The motor pulley 26 and the cylinder pulley 28 are connected by a timing belt 31. Above cylinder pulley 2
Four cylinder blocks 32 are installed on the cylindrical inner surface of 9.
They are installed at 0 degree intervals around the circumference. and,
As shown in FIG. 3, a piston 34 as a pressing member is slidably mounted in the cylinder bore of the cylinder block 32 via a packing 35. Each of these pistons 34 has a spherical head 34a, and a parallel pin 36 vertically passes through the piston body. Both ends of the parallel pin 36 are inserted into and supported by elongated through holes provided in the side wall of the cylinder block 32, and are supported by the piston 3.
It functions as a stopper to prevent it from coming off from the cylinder bore of No.4. Each head 34a is oriented toward the rotation center axis of the cylinder pulley 28, and is guided by the parallel pin 34 in the radial direction (
That is, it is set to slide in the radial direction of the cylinder pulley 28, which is the chuck body. Note that 33 is a lid for sealing air in the cylinder portion.

On the side surface of each cylinder block 32, a workpiece gripping member 37 is fixed at one end with a screw B6 and extends in a cantilevered manner. In the case of this embodiment, the workpiece gripping member 37 is formed of a leaf spring that is an elastic member, extends in a tangential direction to the circumferential surface of the workpiece W supported by the center 4, and has a chuck claw piece 38 at the free end. is fixed. The back surface of the free end faces the head 34a of the piston 34. In this way, the chuck claw piece 38 is attached to the cylinder pulley 2.
It is possible to move toward and away from the outer circumferential surface of the workpiece W by displacing only in the radial direction of the workpiece W.

In order to operate the piston 34 with compressed air, an air port block 4 is provided at the center of the rear surface of the flange 23.
0 (see FIG. 3), and an air circuit 42 is formed from the air port 41 through the flange 23 and cylinder pulley 28 to the rear space of the piston 34. Reference numeral 43 denotes an O-ring as a sealing member for preventing leakage of the air circuit 42, and is attached to the connection point between the flange 23 and the air port block 40. Reference numeral 44 designates a special O-ring as a sealing member for preventing leakage of the air circuit 42, and is installed at the connection point between the flange 23 and the cylinder pulley 28.

Next, the operation will be explained. The screw groove phasing chuck device 20 is initially in the retracted position shown by the chain line in FIG. Furthermore, the piston 34 has also moved backward. When setting the workpiece W on the thread groove phasing device and chucking it with the thread groove phasing chuck device 20, first place the end face of the work W on the thread groove phasing device at both centers (2,
4) It is sandwiched in between and rotatably supported at the center. Thereafter, the slide unit 21 advances the screw groove phase matching chuck device 20 to the position shown by the solid line in FIG.

Next, the piston 34, which is a pressing member, is advanced from the retracted position to press the workpiece gripping member 37 against the outer peripheral surface of the workpiece. This operation is performed by the airport block 40
This is done by sending compressed air from a pressure source (not shown) connected in advance to the air port 41 of the cylinder block 32 through the air circuit 42 to the rear side of the piston 34 in the cylinder bore of the cylinder block 32. This compressed air supply is 4
This is done simultaneously for each cylinder block 32. As a result, the four pistons 34 move forward toward the center of the cylinder pulley 28 at the same time, and strongly press the outer surface of the cylindrical workpiece W through the workpiece gripping member 37 with opposing equal forces. Therefore, the workpiece W can be accurately centered. The workpiece gripping member 37 extends tangentially to the outer peripheral surface of the end of the workpiece W, and its free end is connected to the piston 34.
When placed, the chuck claw piece 3 is elastically deformed and fixed.
8 comes into contact with the outer peripheral surface of the workpiece and clamps it. In this way, the workpiece gripping member 37 is attached to the cylinder pulley 2
8 in the radial direction, and can easily accommodate workpieces W having different outer diameter dimensions.

Next, the stepping motor 25 is started, and the cylinder pulley 28 is connected via the timing belt 31.
drive the rotation. Then, the retaining ring 30b that holds the inner ring of the bearing 29, the four cylinder blocks 32, the lid 33 for sealing the air in the cylinder, the piston 34, the packing 35, the parallel pin 36, the work gripping member 37, and the chuck claw piece 38 rotates together with the cylinder pulley 28. The workpiece W is thus rotated, and the positioning jig 7 is used to perform phase alignment. In that case, the workpiece gripping member 37
is a spring plate and has high rigidity, so the conventional rubber roller 11a,
It will not be deformed like 11b. Therefore, work W
The rotation angle of the cylinder pulley 28 always accurately matches the rotation angle of the cylinder pulley 28, and the rotation can be easily controlled by the stepping motor 25.

After completing the phase alignment using the positioning jig 7, the fixing bolt 5a is tightened to fix the chipping 5. At this time, even if the fixing bolt 5a hits the outer surface of the workpiece W unevenly and rotational force is applied to the workpiece W, the workpiece gripping member 3
7 has its base end fixed to the cylinder block 32 on the inner surface of the cylinder pulley 28, and the displacement of the cylinder pulley 28 in the circumferential direction is completely regulated, so that it can resist the rotational force caused by tightening the fixing bolt 5a. Thus, rotation of the work W can be completely prevented. Therefore, the workpiece does not rotate relative to the gripping member and the phase between the burr and the thread groove is shifted as in the conventional case, and accurate positioning can be achieved. Furthermore, even if there is play between the piston 34 moving in the radial direction of the cylinder pulley 28 and the cylinder bore of the cylinder block 32, the work gripping member 37
Since it abuts and presses the work W through the hole, even if the fixing bolt 5a of the burr is tightened unevenly, there will be no phase shift between the thread groove N and the burr 5 as in the conventional case. When unclamping the workpiece W, the supply of compressed air to the air port 41 is stopped and a switch (not shown) is activated to release the pressure at the rear of the piston 34. Then, the piston 34 retreats due to the elastic restoring force of the workpiece gripping member 37, and the clamping of the workpiece by the chuck claw pieces 38 is released.

In the above embodiment, a case has been described in which compressed air is used to drive the piston 34, but the invention is not limited to this, and other pressure gases or hydraulic pressure may be used. Furthermore, although the piston 34 is used as the pressing means for the workpiece gripping member 37, electrical means such as a solenoid, mechanical means such as a lever, a screw, etc. may also be used.

[0020]

As explained above, the chuck device for thread groove phasing of the present invention is provided with a ring-shaped chuck body formed so that a workpiece supported at the center is inserted into the center of rotation, and the gripping member is formed of an elastic member with one end fixed to the inner surface of the chuck body and the other end displaceable only in the radial direction of the chuck body and brought into contact with the outer peripheral surface of the workpiece. Since a plurality of pressing members for pressing the workpiece are disposed inside the chuck body so as to be movable in the radial direction of the chuck body, the gripping member can easily be displaced to accommodate various workpiece sizes. It has the effect that it does not deform even when gripped, and furthermore, even if rotational force is applied to the workpiece by tightening the fixing bolt, the chipping can be fixed in the correct position without causing a phase shift.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of an embodiment of the present invention.

FIG. 2 is a left side view of FIG. 1.

FIG. 3 is a sectional view taken along line III-III in FIG. 1;

FIG. 4 is a front view of a thread groove phasing device having a conventional chuck device for thread groove phasing.

FIG. 5 is a side view of a conventional chuck device for thread groove phasing.

[Explanation of symbols]

1 Thread groove phasing device 2,
4 Center 10, 20 Chuck device 2 for thread groove phase alignment
8 Chuck body (cylinder pulley) 34 Pressing member (piston) 37
Work gripping member N
Thread groove W work

Claims (1)

[Claims] [Claim 1] The outer peripheral surface of a workpiece having thread grooves on its outer surface and supported between both centers is gripped by a gripping member, and rotation is applied by a rotation device to align the phases of the thread grooves of the workpiece. In the chuck device for thread groove phasing, a ring-shaped chuck body is provided so that the workpiece supported at the center is inserted into the rotation center, and the gripping member has one end fixed to the inner surface of the chuck body. The end is formed of an elastic member that is displaceable only in the radial direction of the chuck body and is brought into contact with the outer circumferential surface of the workpiece, and a pressing member that presses the free end of the gripping member from the back surface is displaceable only in the radial direction of the chuck body. A chuck device for phase alignment of thread grooves, characterized in that it is installed inside a chuck body so as to be movable in the direction.