JPH11309651A - Work driving device for cylindrical grinding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To let the holding pawls of a work driving device be automatically recognized to have been released, and let the center hole of a work to be supported be clamped by a plurality of holding pawls with uniform pressure even if they are in a core slipping state in case of clamping a work onto a cylindrical grinding machine by both its centers. SOLUTION: This work driving device for a cylindrical grinding machine is so constituted that an inner ring plate 4 is fitted in and mounted to the outer circumferential surface of a race center 2 to be inserted into the main spindle side of a grinding machine by way of bearings, and outer race plate 6 is also fitted in and mounted to the outer circumference of the inner ring plate, its end terminal is formed into a fork branched shape, a driving arm 7 provided with a slotted hole and a rotatably supporting hole at its base end side is rotatably supported by the inner ring plate at the slotted hole, and by the outer ring plate back face side at the rotatably supported hole, the driving pin of the grinding machine is engaged with the fork branched part, and a float plate rotatably supporting three holding pawls each tip end of which is formed into a cam shape, is mounted to the surface of the inner ring plate in such a way as to be freely rocked. Besides, a non-magnetic metal is adhered to one tip end of the fork part for the driving arm, so that the opening/closing of each holding pawl can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical grinding machine in which both ends of a work are supported by a center of a main shaft of a machine and a center of a tailstock, and the rotation of a rotary drive plate mounted on the main shaft is transmitted to the work. Related to a work drive device for personal computers.

[0002]

2. Description of the Related Art A ring-shaped clamp member is attached to one end of a work having a center hole at the center of both end faces when grinding the outer peripheral surface of a circular shaft or a cylindrical work with a grindstone. Then, the spindle-side center and the tailstock-side center of the grinding machine support the center holes, and the clamp member abuts on a drive pin protruding from the spindle-side rotary plate to receive rotation power and rotate. It has a structure.

As shown in FIG. 6, a male screw pin 31 is provided on the ring-shaped clamp member at three points on the circumferential surface of the ring-shaped body 30 with the male screw pin 31 facing the axis. At one point, a slightly long support arm 32 having a tip of a cam 32b is rotatably supported on a shaft 32a, and a work held between the pin and the cam is provided with a drive pin attached to a cylindrical grinding machine. By pressing one end of the support arm (in the direction of the arrow) with the support arm (not shown), the work is strongly held and the rotational power is transmitted.

A chuck device shown in FIG.
The cam pawl support plate 33 is perpendicular to the axis of the fixed center at the front end of an inner cylinder fitted to a fixed center of a cylindrical grinding machine via an elastic friction bearing. And stored in the chuck body,
A plate-shaped cam claw 34 of the same shape is attached via a support shaft at three equally circumferential positions on the front surface of the cam claw support plate. Pinions 35 having the same number of teeth are respectively attached to the protruding portions, and the internal gear ring body 36 having the internal teeth formed on the inner peripheral surface is provided in a space formed on the back surface of the cam pawl support plate in the chuck body, It is rotatable integrally with the main shaft face plate, and is disposed so as to be finely movable in the radial direction of the fixed center, and meshes the internal teeth of the internal tooth ring body with each of the three pinions 35, At the start of forward / reverse rotation of the main shaft, by rotation of the internal gear ring body,
The three pinions are rotated synchronously, and the work is gripped and released by the three cam claws that rotate integrally therewith.

Next, a work drive device shown in FIG. 8 is disclosed in Japanese Utility Model Laid-Open No. 5-16022, in which a plurality of clamp claws 38 for clamping a work W to a clamp body 37 are rotated at equal circumferential intervals. A rotation transmission lever 40, which is freely rotatably supported and has a clamp disc 39 rotatably fitted to the main shaft between a rotary drive plate of the grinding machine and the clamp body, and a central shaft portion pivotally supported by the clamp disc. By engaging both ends of the rotary drive plate and the clamp body respectively, the clamp body can be rotated in the opposite direction to the rotation direction of the rotary drive plate with the start of the rotary drive plate. By engaging each of the engaging pins 41 projecting from the clamp disk at the rear end, each clamp claw is interlocked with the rotation of the clamp body in the direction opposite to the rotation direction of the rotary drive plate. A clamp shaft portion 38a rotatable in the direction of the ramp, the clamp claw being pivotally supported by the clamp body 37, and a clamp claw body having a work contact surface at the tip and attached to a front end of the clamp shaft portion by a bolt. And the mounting position of the clamp claw body can be adjusted through a bolt insertion slot 38b penetrating the clamp claw body along a direction substantially perpendicular to the work contact surface.

[0006]

The above-mentioned work drive devices for grinding machines have the following problems. That is, although the one shown in FIG. 6 has a very simple configuration and has a work gripping and driving function, there is an inconvenience that the work must be manually attached to the work.

In the chuck device shown in FIG. 7, when the main shaft of the grinding machine is rotated forward, the three pinions are synchronously rotated at the start of rotation by rotation of the internal gear ring body integrated with the main shaft face plate. A cam claw attached to this pinion via a support shaft rotates synchronously to automatically grip the work. When the main shaft is rotated in the reverse direction, each of the cam claws also rotates in the opposite direction, and the gripping of the work is automatically released. However, when the workpiece is automatically grasped, it is difficult to confirm that the cam claws are completely open, that is, that the workpiece is in a stage before being grasped by the three claws. Was.

[0008] Further, it is a relatively difficult task to accurately machine the tip shape of the cam pawl. When such a cam claw is deformed or damaged for some reason, it is necessary to replace all three at the same time, and the cost and time burden for that are great.

In the drive device shown in FIG. 8, by driving the rotary drive plate of the grinding machine, the clamp disc and the clamp body are rotated in the same direction integrally with the rotary drive plate via the rotation transmission lever. At the initial stage of rotation, the rotation transmission lever is swung by the rotation drive plate about its pivot, so that the clamp body rotates in the opposite direction to the rotation drive plate.
By this relative movement, each clamp claw 38 whose rear end is engaged with the engagement pin is rotated in the clamping direction A, and the work is clamped by each clamp claw. Conversely, when the workpiece is rotated in the B direction, it is released. Also in this drive device,
As described above, it is impossible to confirm whether or not the three clamp claws are open when gripping the work, which hinders the automation of the grinding operation.

In the grinding operation, a center hole is drilled in advance at both end surfaces of the work, but when the center hole is not at the center position with respect to the outer diameter of the work, or a key groove or the like is formed in a part thereof. When the outer shape of the work is deformed, the tip surfaces of the plurality of clamp claws do not evenly contact the work even if the grinding machine is held by both centers, so that there is a problem in that the clamp cannot be performed.

Further, in order to leave no trace of chucking on the work, a clamp claw having a hardness corresponding to the material and hardness of the work should be selected. Central shaft 39
A method of adjusting the clamping force by changing the ratio of the distance from the center shaft 39a to the engagement pin 42 (from the 15th line of the same publication 0027). However, in order to obtain a clamping force that does not leave a gripping indentation on the work, the ratio is adjusted by trial and error, which leaves a problem in workability.

[0012]

According to a first aspect of the present invention, there is provided a race center for supporting a work by inserting a sharpened portion of the work drive device 1 for a cylindrical grinding machine into one of center holes provided at both end surfaces of the work. And an inner race plate 4 fitted and mounted on the outer peripheral surface of the race center 2 via a bearing 3
And an outer ring plate 6 fitted and mounted on the outer periphery of the inner ring plate 4 via a bearing 5, and a donut plate-like float plate 8 swingably attached to the front surface of the inner ring plate 4 as main members. It has a forked bifurcated portion 7a, and has a long hole 7 at its proximal end.
c and a drive arm 7 having a shaft support hole 7b slightly closer to the center thereof is slidably supported on the rear surface of the inner race plate 4 by the elongated hole 7c, and the shaft support hole 7b is rotated on the rear surface of the outer race plate 6. The gripping claws 9, 9, 9 each having a cam-like tip 9 c and a bifurcated branch finger 9 a at three equally spaced positions on the surface of the float plate 8 are freely rotatable around the center thereof. Support bolt 9
d, 9d, 9d, drive pins 10, 10, erected on the surface of the outer race plate 6 within the forked branch finger 9a.
The above-mentioned problem has been solved as a structure for engaging the ten.

According to a second aspect of the present invention, the float plate 8 has a simple structure in which the float plate 8 can be attached and detached from the front side of the apparatus attached to the cylindrical grinding machine with the support bolt 18.

According to a third aspect, the tip cam-like portion 9c of the gripping claw 9 is configured as a detachable tip 19.

According to a fourth aspect of the present invention, the tip end surface of the tip 19 is constituted by an arcuate cam surface, an inclined flat surface and a slightly concave cam surface formed so as to grip the workpiece by rotation. .

Further, a means for attaching a sensor dog 15 made of a non-magnetic material such as a non-ferrous metal to one end of the forked branch 7a formed at the end of the drive arm 7 is provided. We decided to combine these sensors.

[0017]

In the work drive device for a cylindrical grinding machine, the driving pin 22a attached to the face plate 22 of the cylindrical grinding machine 20 is engaged between the terminal forked branch portions 7a of the driving arm 7 on the main body side. The rotation of the main shaft of the grinding machine first rotates the end of the drive arm 7. Therefore, the drive arm 7 having the support shaft on the outer race plate 6 advances with its support shaft 17 as a fulcrum so that the distal end falls down in the rotation direction of the main shaft, and at the same time, the base end rotates in the opposite direction. As a result, the inner race 4 rotates relative to the outer race 6 in the opposite direction. Due to the relative movement between the inner race plate 4 and the outer race plate 6, the forked bifurcated finger portion of the gripping claw 9 advances in the main shaft rotation direction with the support bolt 9d as a fulcrum, and the tip cam 9c rotates in the opposite direction. Work will be clamped. At the time of stop, the spindle of the cylindrical grinder is programmed to rotate in the opposite direction at the same time as the stop, so that the end of the drive arm 7 falls in the opposite direction to that in the grinding process, and the inner race plate 4 and the outer race The relative position with respect to the plate 6 is reversed, so that the three cam portions 9c, 9c, 9c are opened.

In this apparatus, claim 1 is as follows.
The float plate 8 on which the gripping claws 9 are pivotally supported is the inner race plate 4
Is mounted on the surface of the workpiece so as to be swingable in the direction perpendicular to the main shaft, so that even if the center holes drilled on both end faces of The movement absorbs the eccentricity and makes it possible to securely clamp by the three gripping claws. Therefore, the shape of the clamp portion of the work does not necessarily have to be circular.

According to the second aspect, the chuckable position of the work supported by the sharp portion of the race center may vary depending on the shape thereof. By selecting and attaching a float plate having an appropriate thickness to this, The position of the gripping claw was moved in the front-rear direction to make it correspond. In addition, it is possible to remove the float plate and use normal drilling, and it can handle large-diameter workpieces.

According to a third aspect of the present invention, the tip of the gripping claw is configured to be detachable, so that the contact surface with the workpiece is made of the material of the workpiece,
It is possible to easily select and attach a material having a hardness corresponding to the hardness, and thus has an effect of leaving no gripping marks on the work.

According to a fourth aspect of the present invention, by setting the surface shape of the tip of the gripping claw to be various, a tip having a normal convex cam surface is used for a workpiece having a small diameter, and a flat tip is provided for a workpiece having a large diameter. Alternatively, a chip having a concave cam surface was selected, the work was clamped by the surface, and no clamp impression was left.

According to a fifth aspect of the present invention, during the grinding operation and during the stop, the angle of the drive arm 7 moves in the front-rear direction with respect to the center direction of the present apparatus, so that the orbit of the tip of each of the bifurcated portions is reduced. Utilizing the difference, the sensor mounted outside the device detects that the tip of the forked portion with the sensor dog at the time of stop is on the outer (or inner) side. It is possible to give instruction information.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a work drive device for a cylindrical grinding machine according to the present invention will be described with reference to the drawings. FIG. 1 is a central longitudinal sectional view showing a state in which a work drive device 1 according to the present invention is inserted through a spindle of a cylindrical grinder (a part of the tip of which is shown by phantom lines in the figure), and FIG. FIGS. 3 and 3 are front views showing a sensor for detecting the opening and closing of the gripping claw from the rotation trajectory of the bifurcated branch of the drive arm, FIG. 4 is an exploded view of the gripping claw, and FIG. FIGS. 6 to 8 show a conventional type kerf and work clamping device.

In the work drive device according to the present invention, an inner race plate 4 is fitted and mounted on the outer diameter of a race center 2 via a bearing 3 with a race center 2 inserted and fitted in a tapered main shaft hole provided in a cylindrical grinding machine. The outer ring 6 is fitted and mounted on the outer diameter of the inner ring 4 via a bearing 5, and the back side (the projecting side of the sharp portion 2 a of the race center is the front side, and the main shaft (power) side is the back side). The same applies to the following.) To which the bearing cover 11 is attached. The race center 2 and the inner race 4 and the inner race 4 and the outer race 6 at this stage are rotatable.

The drive arm 7 has an elongated hole 7c at its base end, a shaft support hole 7b closer to the center thereof, and a bifurcated branch 7a formed at the end. One end surface of the branch is provided. Non-magnetic metal materials (for example, aluminum, copper, brass,
Zinc, solder, SUS304, titanium and the like can be mentioned, but those which respond to the sensor used may be used. ) Is provided as a sensor dog (detected body) 15. A guide pin 4a protruding from the back surface of the inner race plate 4 is inserted into the elongated hole 7c of the base end of the drive arm 7 so as to be slidable back and forth, and the support shaft 17 is inserted into the shaft support hole 7b to form an outer ring. It is pivotally supported on the back surface of the plate 6. Thus, the rotation of the outer race plate and the inner race plate is limited by the movable distance in the elongated hole 7c of the guide pin 4a. The distal end of the drive arm 7 protrudes outward from the outer periphery of the outer race plate 6, and a rotary drive pin 22 protruding from a face plate 22 on the main shaft side of the cylindrical grinding machine between its forked branches 7 a.
a, so that the transmission of rotational power is received.

The float plate 8 has a through hole 8a at the center thereof, through which the sharp portion of the race center is inserted, and mounting holes 8b, 8b, 8b concentric with the through hole 8a. It is attached to the surface of the inner race plate 4 by a supporting bolt 18 having a neck portion smaller than the diameter of the hole 8b by about 0.5 to 3 mm. As a result, the float plate 8 can be slid about 0.5 to 3 mm in a diametrical direction on the surface of the inner race plate 4. Although the sharp portion 2a of the race center is located substantially on the same line as the surface of the float plate 8 attached in this manner, depending on the shape of the work, a thick or small float plate is attached. Change the position from the end face of the work,
Can be clamped.

The three gripping claws 9, 9 and 9 for gripping the work and transmitting the rotation to the work are formed with a mounting groove 9b for detachably mounting a tip 19 having a cam-like surface 9c at the tip, and a bifurcated end at the end. It has a shape having a branch finger 9a in a shape, and a nail driving pin 10 erected on the surface side of the outer ring plate 6 is slidably held between the branch fingers 9a, and the center of the gripping nail 9 or Shaft hole 9h opened near the tip 19 side
The support bolt 9d is inserted through the support member 9w and is rotatably supported on the inner race plate 4 at a position on the inner race plate 4 at equal intervals via a support base 9w.
By inserting the head of the support bolt 9d so as not to protrude from the surface of the gripping claw, the side surface of the grinding wheel can be ground close to the gripping claw.

Although the structure of the chip mounting groove 9b in the gripping claw 9 is not particularly limited, the gripping claw 9 has a trapezoidal opening at the tip as described with reference to FIG. An insertion groove 9b is formed vertically from the front surface to the rear surface of the gripping claw, and the insertion groove 9b is formed.
A slit 9s is cut from the bottom surface of the gripping claw toward the center of the gripping claw, and a screw hole 9 orthogonal to the slit 9s surface is formed.
n is pierced from the side of the gripping claw. This insertion groove 9
b has a base 19a having the same shape as the trapezoid of the insertion groove 9b, and the tip thereof has a cam-like shape 9c.
Formed. The chip is firmly held by inserting the trapezoidal base 19a into the groove 9b and inserting and screwing the screw 13 into the screw hole 9n.

FIG. 4B shows another embodiment, in which a screw hole 9n is provided so as to be orthogonal to the side surface of the insertion groove 9b formed at the tip of the gripping claw 9, and the insertion is performed. The side surface of the base 19a of the chip 19 inserted into the groove 9b is directly pressed and held by screws or bolts 13a.

The thickness t of the chip is not necessarily the gripper 9
Does not need to be the same as the thickness T. If the tip protrudes from the front surface of the gripping claw 9, it is possible to clamp the front side of the end face of the work, and by bringing the grindstone G close to the chip or grinding the chip surface simultaneously with the work. It can be applied to a work having a small clamping margin (the thickness of the flange portion F in FIG. 5).

The tip 19 is made of a super-steel, steel, iron or a non-ferrous alloy such as brass, brass, aluminum or the like, a plastic, or the like. Material close to it,
Hardness is selected and installed. Also, the tip of the tip has been described as a cam shape, but the present invention is not limited to this. For example, a flat surface having a slight gradient (95 to 135 degrees) from a right angle to the longitudinal direction of the gripping claw 9 Alternatively, a rounded surface with a concave shape may be used. With such a shape, the gripping area increases in the chucking of the columnar work, so that the surface pressure is small and gripping traces are reduced.

The work drive 1 device for a cylindrical grinding machine according to the present invention has the above-described structure. Next, a method of using the same will be described. A drive pin 2 projecting from a rotary plate 22 of a cylindrical grinding machine 20 between a forked branch 7a at the end of a drive arm 7 of the apparatus 1
The race center 2 is inserted and attached to the main shaft taper hole 21 so as to insert the race center 2a. And the face plate 22 of the machine
Is rotated in the opposite direction, first of all, the drive arm 7 of the device 1
However, the distal end side of the support shaft 17 is rotated in the same direction as the fulcrum with the shaft support 7b as a fulcrum, and the distal end side of the support shaft 17 is rotated in the opposite direction. Rotate in the direction. As a result, the claw drive pin 10 protruding from the outer race plate 6 rotates around the gripping claws 9, 9, 9 with the shaft support portion (support bolt 9d) as a fulcrum, thereby increasing the relative distance between the three cam surfaces. , The work can be inserted.

In this state, the work W having the center holes formed at both end surfaces is supported between the race center 2 and the tailstock side center 23, and then the face plate 22 of the cylindrical grinding machine is supported.
Is rotated forward. Due to this forward rotation, the drive arm 7 first rotates in the opposite direction to the above, thereby rotating the relative position between the inner race plate 4 and the outer race plate 6 in the opposite direction. Therefore, the tip end of the cam-shaped tip of the gripping claw 9 is narrowed in the opposite direction to clamp the work to transmit the rotation of the machine.

According to the apparatus according to the present invention, even if the center holes provided on both end faces of the work cause a center runout with respect to the outer diameter, the swingable free-wheel mounted on the inner ring plate 4 is provided. The float plate 8 swings according to the eccentricity of the work outer diameter, and a uniform clamping pressure is obtained on each cam surface for clamping at the eccentric position, and an eccentric load is applied to both center supports. No grinding is required, and perfect circular grinding becomes possible.

If the machine spindle is programmed to rotate in the opposite direction when the grinding machine stops, the drive pins 22
In a, the drive arm 7 is pulled back in the opposite direction, and the inner race 4 is rotated in the opposite direction to that during the grinding process. Therefore, the gripping claws release the clamp of the work. Usually, this causes the work to be taken out of the machine by a robot or the like.

At this time, the two ends of the bifurcated branch 7a formed at the end of the drive arm 7 have one or more outer circumferences, and the other has an orbit close to the inner circumference (FIG. 3). Since the sensor dog 15 made of a nonmagnetic metal is attached to one end face of the forked branch on the outer peripheral side as described above, the sensor 12 (commercially available) provided at a position about 2 to 10 mm away from the outer peripheral track is provided. An example of this is "Aluminum Proximity Switch" manufactured by KEYENCE CORPORATION.) When it is detected, for example, that aluminum orbits around the outer peripheral side, the control system is notified that the gripping claws are open, and the next process is performed. Instruction information. Although FIG. 3 shows that two sensors are installed, it goes without saying that one sensor may be provided.

Next, another method of use will be described. The support bolts 18, 18, 18 are removed from the front side of the device 1, and the float plate 8 (and thus the gripping claws) is removed from the inner race plate 4. In this state, the drive pin 10 protrudes forward from the sharp portion 2a of the race center.
The grinding work can be performed by a method in which a work with a conventional type of knurling as shown in FIG. As described above, the float plate is removed by a simple operation from the front side of the present apparatus 1 attached to the cylindrical grinder, so that it is possible to cope with a work having a large diameter. When the clampable position of the work is close to the end surface of the work, the float plate 8 having a small plate thickness is selected, and when the clamp position is far from the end surface, the float plate having a large plate thickness is selected and mounted. .

[0038]

According to the work drive device for a cylindrical grinding machine of the present invention, the float plate supporting the gripping claws can swing freely in the direction perpendicular to the axial direction of the race center. Each of the gripping claws evenly clamps a workpiece having an eccentric outer peripheral surface, so that an eccentric load is not applied to both center supports, thereby enabling perfect circular grinding.

When a workpiece is forcibly clamped by an automatic gripping (clamping) claw as in the present apparatus, a perfect circle may not be often obtained in a ground workpiece. This is due to the center runout of the race center, damage due to partial wear, etc., uneven wear of the gripping claws, etc. In order to know the cause, it is necessary to remove the float plate 8 from the above-described apparatus. By driving and grinding using a conventional basic tool, it is possible to determine the cause of the above-mentioned roundness failure, but this can be quickly dealt with.

Since the tip 19 can be freely attached to and detached from the tip of the gripping claw 9, it is easy to select and attach a chip having a hardness corresponding to the hardness of the work, and therefore, no trace of gripping is generated on the work. .

In addition, since the tip surface of the tip is a flat surface or a concave cam surface, the area of gripping and pressing against a circular work is larger than that of a tip having a convex cam surface, which may cause gripping marks. It has run out.

As described above, the drive arm 7 of the present drive device
A non-magnetic material is attached to one of the end bifurcated branches 7a, and by using the sensor in combination with a sensor for detecting the non-magnetic material, it is always possible to confirm whether the tip cam portion of the gripping claw 9 is open or closed. This has made it possible to reliably automate the chucking work of the work.

[Brief description of the drawings]

FIG. 1 is a central longitudinal sectional view of a work drive device according to the present invention.

FIG. 2 is a front view of the work drive device.

FIG. 3 is a front view showing a rotation trajectory according to the position of a driving arm and showing a sensor for detecting the open / closed state of the gripping claw from the trajectory.

FIG. 4 is an exploded view showing two examples of an assembling method of the gripping claws.

FIG. 5 is a side view showing an example of clamping a work.

FIG. 6 is a front view of a conventional example, which is an early type viper.

FIG. 7 is a front view of a conventional chucking device having a structure in which a gear and a pinion are engaged with each other.

FIG. 8 is a front view of a conventional work clamp device having a chucking strength adjustment function.

[Explanation of symbols]

 Reference Signs List 1 work drive device for cylindrical grinding machine 2 race center 3 bearing 4 inner ring plate 5 bearing 6 outer ring plate 7 drive arm 8 float plate 9 gripping claw 10 drive pin 12 sensor 15 sensor dog 19 chip

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[Procedure amendment]

[Submission date] March 10, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

2. A trapezoidal engagement with a tip of a work gripping claw (9).
A trapezoid that forms a groove and can be inserted into this groove in the chip (19)
2. The circle according to claim 1, wherein a projection is formed.
Work gripping claw for work drive device for cylindrical grinder.

3. A tip of a tip detachably attached to a tip of a work gripping claw (9) , and a middle recessed round surface is formed at a tip of the tip.
4. The chip according to claim 3, wherein the chip is provided.

4. The work drive device for a cylindrical grinding machine according to claim 1, wherein a sensor dog (15) made of a non-magnetic material is attached to one end of the terminal branch portion of the drive arm (7).

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

Further, with a pivot bolt 18 from the front side of the device attached to the cylindrical grinder and a simple structure that can be attached to and detached the float plate 8.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

According to the second aspect , the tip cam-like portion 9c of the gripping claw 9 is configured as a detachable tip 19.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

[0015] According to aspect 3, the <br/> distal end surface of the chip 19 by a respective pivoting arcuate cam surface formed so as to grip the workpiece, the inclined planar surface and slight concave cam surface It is composed.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

Further, a means for attaching a sensor dog 15 made of a non-magnetic material such as a non-ferrous metal to one end of the forked branch 7 a formed at the end of the drive arm 7 is provided in the fourth aspect , We decided to combine these sensors.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

In addition, the chucking position of the work supported by the sharp portion of the race center may vary depending on its shape. In response to this, by selecting and attaching a float plate having an appropriate heat, the gripping claws can be formed. The position was moved in the front-back direction to make it correspond. In addition, it is possible to remove the float plate and use normal drilling, making it possible to handle large-diameter workpieces.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

According to a third aspect of the present invention, the distal end of the gripping claw is configured to be detachable, so that the contact surface with the workpiece can be easily selected and attached with a hardness according to the material and hardness of the workpiece. Therefore, there is an effect that a gripping mark is not left on the work.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

The third aspect of the present invention relates to the tip of the gripping claw tip.
By setting the tip shape in various ways, a chip with a normal convex cam surface is selected for a workpiece with a small diameter, and a chip with a flat or concave cam surface is selected for a large workpiece. The surface was clamped, and no clamp impression was left.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

According to a fourth aspect of the present invention, during the grinding operation and during the stop, the angle of the driving arm 7 moves in the front-rear direction with respect to the center direction of the present apparatus, so that the circumferential miracle at the tip of each of the forked portions is reduced. Utilizing the difference, the sensor mounted outside the device detects that the tip of the forked part with the sensor dog attached to the outer circumference (or inner circumference) side at the time of stop is detected by the sensor mounted outside the device, and confirms the release of the gripping claws. To give information.

Claims (5)

[Claims] 1. A race center (2) for supporting a work by inserting the sharpened portion into one of center holes provided on both end faces of the work, and a bearing (3) on an outer peripheral surface of the race center. A support shaft (4a) on the back side where the fitting is mounted
A protruding inner ring plate (4), three driving pins (10) fitted on the outer periphery of the inner ring plate via a bearing (5) and mounted on the surface side, and a protruding outer ring plate (6) It is formed in a bifurcated branch shape, and a long hole and a shaft support hole are formed on the base end side, a support shaft protruding from the back surface of the inner ring plate (4) is inserted into the long hole, and a shaft support hole portion is formed on the back surface of the outer ring plate. A drive arm (7) rotatably supported by a shaft (17) and a through hole at the center through which the sharp portion of the race center is inserted, and three mounting holes are formed at equal intervals on a concentric circle of the disk surface. A float plate (8) swingably mounted on the surface of the inner race plate by a bolt having a neck portion smaller than the diameter of the mounting hole; And a drive pin provided upright in the vicinity of the outer periphery of the outer race plate on the front side thereof is engaged between the forked branch fingers formed at the distal end. , Cylindrical grinding machine a work drive device consisting of a gripping claw forming the tip cam profile (9). 2. The float plate on which the gripping claw is pivotally supported is slidable on the inner ring plate surface, and is detachable by operation from the front side of the float plate. Work drive device for cylindrical grinding machines. 3. The work for a cylindrical grinding machine according to claim 1, wherein the gripping claw (9) has a structure in which a tip (19) having a cam-shaped portion (9c) at its tip is detachable. Drive device. 4. The tip of the tip which can be detachably attached to the tip of the workpiece gripping claw is a cam-shaped round surface, a flat surface having an inclination angle of 95 to 135 degrees with respect to the longitudinal direction of the gripping claw, or a concave surface. 4. The chip according to claim 3, wherein the round surface is formed. 5. The work drive device for a cylindrical grinding machine according to claim 1, wherein a sensor dog (15) made of a non-magnetic material is attached to one end of the terminal branch portion of the drive arm (7).