JP3142629U - Lathe work holding jig - Google Patents

Abstract

Provided is a lathe work holding jig capable of gripping a thin cylindrical work piece without causing distortion, and shortening the setup of holding jig replacement.
SOLUTION: The chuck device comprises three parent claws 3 attached to a claw receiving base 8 that slides in a radial direction on a rotating disk and a gripping claw 4 fixed to the parent claw. A plurality of arc-shaped concave grooves 16 and 17 having the rotation center of the rotating disk 2 as the arc center are formed on the surface portion of the parent nail with different diameters in the attached state. The gripping claw has a donut disk shape obtained by cutting a donut disk into three circumferentially divided portions with a radial slit, and an arc-shaped back convex protrusion that fits into one of the arc-shaped concave grooves of the parent nail is formed on the back surface. The center of the donut disk is provided as the arc center. Similarly, arc-shaped surface convex protrusions are provided on the surface. The inner side surface of the convex surface projection is processed with a radius of curvature that matches the outer peripheral surface of the cylindrical workpiece and the outer side surface matches the inner peripheral surface.
[Selection] Figure 2

Description

  The present invention relates to a holding jig for gripping a workpiece when cutting with a lathe, and in particular, it can grip a thin cylindrical workpiece without distortion, and is a setup for switching to machining of a workpiece having a different diameter. The present invention relates to a workpiece holding jig for an assembly type lathe capable of reducing time.

  In machining by a lathe, a workpiece is gripped and rotated by a chuck device provided at a spindle end of the lathe, and a tool such as a cutting tool is used to perform cutting and grinding such as cylindrical grinding, internal grinding, and end grinding. The chuck device includes a rotating disk that rotates integrally with the spindle, three claw bases that are provided at equal intervals in the circumferential direction of the rotating disk, and that are simultaneously slid in the radial direction, and are fixed to each claw base. A three-jaw scroll chuck comprising a gripping claw for directly gripping a workpiece is widely used.

  The gripping claw is generally formed in an elongated rectangular parallelepiped block. As shown in FIG. 10, an inner claw 51 for gripping a rod-shaped workpiece and an outer claw 52 for gripping a disk-shaped workpiece such as a flange as shown in FIG. It is common. However, when the workpiece is a thin cylindrical object, if the workpiece is gripped with such a claw, the workpiece is distorted by the gripping force, so that it cannot be cut or ground to a uniform thickness. In addition, the toe surface of the gripping claw that comes into contact with the workpiece needs to be formed into a rounded contact surface that matches the outer surface shape of the workpiece so as not to damage the workpiece. Therefore, when there are many types of workpieces, a large number of gripping claws having different round shapes must be prepared, and three gripping claws must be replaced each time the workpiece is changed. Since the gripping claws are firmly fastened and fixed to the claw cradle by bolts, there is a problem that the replacement takes time and the workability is poor.

  Various types of gripping claws have been conventionally proposed for handling a plurality of types of cylindrical workpieces having different outer diameters and inner diameters with good setup. For example, in Patent Document 1, a regular hexagonal block-shaped child claw is attached to an adapter fixed to a claw cradle, different toes are formed on six regular hexagonal faces, and the toe is selected by fitting to the adapter. Thus, a holding jig that can grip a workpiece is disclosed.

Also, in Patent Document 2, four toes having different shapes are formed on the outer peripheral surface of the workpiece support member on the nail cradle with the same idea, and the toe shape can be selected by rotating the workpiece support member. Such a holding jig is disclosed. With these holding jigs, it is not necessary to replace the nail cradle, and the toe shape can be selected with a relatively simple operation. And since one kind of nail (work support member) can cope with a plurality of kinds of work, workability is good. However, it is difficult for any of the holding jigs of Patent Documents 1 and 2 to increase the area of the toe surface contacting the workpiece. Therefore, when a thin cylindrical workpiece is sandwiched from three directions, there is a problem that a large force is applied to the workpiece portion that contacts the toe surface and the workpiece is distorted.
JP 2002-137105 A Japanese Utility Model Publication No. 59-93806

  The present invention has been made to solve such problems of the prior art, and the problem is that a thin cylindrical workpiece can be gripped without causing distortion, and the holding jig is replaced when changing the workpiece. An object of the present invention is to provide a lathe workpiece holding jig that can perform the above-mentioned setup in a short time.

  Means for solving the above problems will be described with reference numerals of embodiments to be described later. The device according to claim 1 is arranged at equal intervals in the circumferential direction of the rotating disk 2 that rotates integrally with the main shaft of the lathe. A lathe work holding jig 5 that is fixed to three claw bases 8 that are attached and slid simultaneously in the radial direction and grips a work piece, and is fixed to each claw base 8 with bolts. A main claw 3 and a grip claw 4 that is attached to the main claw 3 and grips the workpiece 30. 2 are fixed in bolts in the radial direction, and each parent claw 3 has the same shape and has a circular arc-shaped groove 16 with the center of rotation of the rotating disk 2 in the fixed state on the surface thereof. , 17 are formed, and each gripping claw 4 has the same shape, and the donut disk is divided into three pieces in the circumferential direction. Is formed into a three-part donut disk shape 23 cut by a radial slit, and on the back surface thereof is an arc-shaped back convex protrusion 24 fitted into one of the arc-shaped concave grooves 16 and 17 provided in the parent claw 3. Is provided with the center of the donut disk as the center of the arc, and the surface thereof is provided with an arc-shaped surface convex protrusion 25 having the center of the donut disk as the arc center, and the inner side surface of the surface convex protrusion 25 is a cylindrical outer surface. And the outer side surface is processed with a curvature radius suitable for the inner peripheral surface of the workpiece 30 having a cylindrical inner surface, and each gripping claw 4 is appropriately positioned. A lathe machining is characterized in that a fixing bolt is passed through an insertion hole 27 penetrating from the front surface to the back surface of the claw, and is screwed and fixed to a screw hole 20 provided in each claw base 8. It is an object holding jig.

  The effect of the lathe work holding jig of the present invention will be described with reference numerals of embodiments described later. When the cylindrical work piece 30 is gripped on the outer peripheral surface by the holding jig 1 of this configuration, the gripping claws that are first slid outwardly and fixed to the three parent claws 3 are held. The opening formed by the surface convex protrusions 25 is widened, and the workpiece 30 is inserted into the widened opening. In this state, the claw receiving base 8 is slid inward, and the outer peripheral surface of the workpiece 30 is clamped by the inner side surface of the surface convex protrusion 25 of the gripping claw 4. Since the radius of curvature of the inner side surface of the convex surface protrusion 25 is matched to the radius of curvature of the outer peripheral surface of the workpiece 30, no gap is formed between the inner side surface of the gripping claw 4 and the outer peripheral surface of the workpiece 30. The entire outer peripheral surface of the workpiece 30 is gripped in a state where it is in contact with the three surface convex protrusions 25. For this reason, even if the workpiece 30 is a thin object, there is an advantage that distortion due to gripping does not occur.

  Further, when the cylindrical workpiece 30 is gripped from the inner peripheral surface thereof, the surface protrusions of the gripping claws 4 that are first slid inwardly and fixed to the three parent claws 3. The opening formed by the protrusion 25 is narrowed. In this state, the workpiece 30 is mounted, the claw cradle 8 is slid outward, and the workpiece 30 is gripped from the inner peripheral surface by the outer side surface of the convex protrusion 25 of the gripping claw. Since the radius of curvature of the outer side surface of the surface convex protrusion 25 is matched to the radius of curvature of the inner peripheral surface of the workpiece, a gap is generated between the outer side surface of the surface convex protrusion 25 and the inner peripheral surface of the workpiece 30. Instead, the entire inner peripheral surface of the workpiece 30 is gripped in a state where the three surface convex protrusions 25 are in contact with each other. For this reason, even if the workpiece 30 is a thin object, there is an advantage that distortion due to gripping does not occur.

  Further, in the holding jig 1 of this configuration, it is not necessary to replace the parent claw 3, and it is only necessary to replace the grip claw 4 with one that matches the size of the workpiece 30. The force acting in the radial direction of the grip claw 4 during cutting is received by the side surfaces of the concave grooves 16 and 17 provided in the parent claw 3. Therefore, it is not necessary to attach the gripping claw 4 firmly to the parent claw 3, and it is sufficient if it is fastened with a small bolt. Since the replacement can be performed more easily than the replacement of the parent claw 3 firmly fixed to the claw base 8, there is an advantage that the setup time can be shortened.

  Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. FIG. 1 is an overall perspective view of a lathe chuck device 1 equipped with a lathe work holding jig 5 according to the present invention, and FIG. 2 is a divided perspective view thereof. The lathe chuck device 1 includes a rotating disk 2 that is a main body of the chuck device 1 and a workpiece holding jig 5 including three parent claws 3 and gripping claws 4.

  The turntable 2 is attached to the spindle end of the lathe and is driven to rotate counterclockwise as viewed from the holding jig 5 side. The rotating disk 2 is provided with three guide grooves 7 extending radially from the rotation center at equal intervals of 120 ° in the circumferential direction. Each guide groove 7 is provided with a claw base 8 that is simultaneously slidable in the radial direction by a hydraulic drive unit built in the rotating disk 2. The surface portion of the claw cradle 8 has a substantially rectangular shape that is long in the radial direction of the turntable 2, and is fitted with a concave sliding groove 9 provided on the back surface of the parent claw 3 at the center in the width direction. Convex protrusions 10 are provided in the longitudinal direction. Two screw holes 11 for fixing the parent nail 3 are formed on the surface of the convex protrusion 10. Further, serrations 14 that mesh with the serrations 13 on the back surface of the parent claw 3 are provided on both sides of the convex protrusion 10.

  The three parent claws 3 are formed in the same shape. 3 is a perspective view of the front surface side of the parent nail 3, and FIG. 4 is a perspective view of the back surface side. The parent claw 3 has a substantially rectangular parallelepiped shape, and the tip portion on the rotation center side of the turntable 2 is formed narrow so as to avoid interference with the adjacent parent claw 3. A plurality of arc-shaped grooves (in this embodiment, two grooves 16 and 17) are provided on the surface side of the parent claw 3. The arc-shaped concave grooves 16 and 17 have three parent claws 3 in a state in which the parent claws 3 are fixed to the claw cradle 8 and each claw cradle 8 is slid and stopped at a predetermined position in the radial direction of the rotating disk 2. The upper arc-shaped concave grooves 16 and 17 are formed with such a curvature that they are located on the same circle centered on the rotation center of the rotating disk 2.

  Therefore, when the three claw bases 8 are slid and stopped at such predetermined positions in the radial direction, the arc-shaped concave grooves 16 and 17 of the three fixed parent claws 3 have a radial thickness. Cylinders equal to the groove widths of the grooves 16 and 17 and whose inner surface side radius and outer surface radius are equal to the radius of curvature of the radially inner surface and radially outer surface of the arc-shaped concave grooves 16 and 17 can be completely fitted. .

  As shown in FIG. 4, a concave sliding groove 9 is formed in the central longitudinal direction on the back side of the parent claw 3, and serrations 13 that engage with the serrations 14 of the claw base 8 are provided on both sides thereof. . A bolt insertion hole 19 with two counterbore parts penetrating from the front surface side to the back surface side of the parent claw 3 is provided, and a fixing bolt (not shown) is passed through the bolt insertion hole 19 to allow the claw cradle 8 to be inserted. The parent claw 3 is fixed to the claw cradle 8 by being screwed into the screw hole 11. FIG. 5 is a perspective view of a state in which the three master claws 3 are fixed to the claw cradle 8 of the rotating disk 2. Note that two screw holes 20 for fixing the gripping claws 4 are provided at the bottoms of the respective arc-shaped concave grooves 16 and 17.

  Three gripping claws 4 are also used as shown in FIG. FIG. 6 is a perspective view of one of them as seen from another angle. The gripping claw 4 includes a three-part donut disk 23 having a shape obtained by cutting a donut disk at a three-part circumferential direction with a radial slit, an arc-shaped back convex protrusion 24 provided on the back side, and a front surface side. It comprises a similarly arc-shaped surface convex protrusion 25 provided. The three-divided donut disk portion 23 is obtained by cutting the donut disk with a slit, and the arc center angle is slightly smaller than 120 °.

  The back convex protrusion 24 is formed in an arc shape with a radius of curvature that fits into one of the arc-shaped concave grooves 16 and 17 provided in the parent claw 3. Accordingly, in a state in which it is fitted and attached to one of the arcuate grooves 16, 17 of the parent claw 3, the three back projections 24 coincide with the center of rotation of the rotating disk 2 (the arc center of the three-part donut disk part 23). ) Is located on the same circle centered on.

  The arc-shaped surface convex protrusions 25 provided on the surface side of the three gripping claws 4 are also fitted to one of the arc-shaped concave grooves 16 and 17 of the parent claw 3 so that the center of rotation of the rotating disk 2 is maintained. It is formed so as to be located on the same circle as the center. The inner side surface of the surface convex protrusion 25 is processed with a radius of curvature that matches the outer peripheral surface of the workpiece having a cylindrical outer surface. The outer side surface is processed with a radius of curvature that matches the inner peripheral surface of the workpiece having a cylindrical inner surface. In order to fix the gripping claws 4, two small-diameter bolt insertion holes 27 with counterbore portions penetrating from the surface of the three-part donut disk portion 23 to the protrusion surface of the back convex protrusion 24 are provided. A small fixing bolt is inserted into the bolt insertion hole 27 and screwed into a screw hole 20 provided at the bottom of the arc-shaped concave grooves 16 and 17 to fix the gripping claw 4 to the parent claw 3. The attachment position of the small fixing bolt for fixing the gripping claw 4 to the parent claw 3 is not necessarily limited to a portion penetrating the back surface protrusion 24, and an appropriate position where the gripping claw 4 can be fixed to the parent claw 3. It's okay. The lathe chuck device 1 that has been assembled is as shown in the perspective view of FIG.

  FIG. 7 is a perspective view showing a state in which the cylindrical workpiece 30 is gripped on the outer peripheral surface by the lathe chuck device 1 having such a configuration. When the workpiece 30 is gripped, the opening formed by the surface protrusions 25 of the gripping claws 4 fixed to the three parent claws 3 by first sliding the claw cradle 8 outward is widened and widened. The workpiece 30 is inserted into the opened opening. In this state, the claw receiving base 8 is slid inward, and the outer peripheral surface of the workpiece 30 is clamped by the inner side surface of the surface convex protrusion 25 of the gripping claw 4. Since the radius of curvature of the inner side surface of the convex surface protrusion 25 is matched to the curvature of the outer peripheral surface of the workpiece 30, no gap is formed between the inner side surface of the gripping claw 4 and the outer peripheral surface of the workpiece 30. Nearly the entire outer peripheral surface of the workpiece 30 is gripped in contact with the three surface protrusions 25. For this reason, even if the workpiece 30 is a thin object, there is an advantage that distortion due to gripping does not occur.

  FIG. 8 is a perspective view showing a state in which the cylindrical workpiece 30 is gripped from the inside by the lathe chuck device 1. When the workpiece 30 is gripped, the opening formed by the surface protrusions 25 of the gripping claws 4 fixed to the three parent claws 3 is first narrowed by sliding the claw base 8 inward. In this state, the workpiece 30 is mounted, and the claw cradle 8 is slid outward to grip the workpiece 30 from the inner peripheral surface with the outer side surface of the surface protrusion 25 of the gripping claw. Since the radius of curvature of the outer side surface of the surface convex protrusion 25 is matched to the curvature of the inner peripheral surface of the workpiece, there is no gap between the outer side surface of the surface convex protrusion 25 and the inner peripheral surface of the workpiece 30. Then, the entire inner peripheral surface of the work piece 30 is gripped in a state where the three surface convex protrusions 25 are in contact with each other. For this reason, even if the workpiece 30 is a thin object, there is an advantage that distortion due to gripping does not occur.

  In the embodiment of FIG. 1, the gripping claw 4 is fitted in the outer circular arc-shaped groove 16 provided in the parent claw 3, but when the diameter of the workpiece 30 is small, the gripping claw 4 is small. It is good to make it fit in the arcuate groove 17 inside. 7 and 8, the workpiece 30 is gripped by the gripping claws 4, but when the workpiece 30 is a small-diameter solid round bar or thick cylinder, the gripping claws 4 are used. Instead, as shown in FIG.

FIG. 3 is a perspective view of a lathe chuck device 1 equipped with a lathe work holding jig 5. It is a division | segmentation perspective view of the chuck apparatus 1 for lathes. 3 is a perspective view of the front side of the parent nail 3. FIG. 3 is a perspective view of the back side of the parent nail 3. FIG. FIG. 3 is a perspective view of a state in which three parent claws 3 are fixed to a claw cradle 8 of a turntable 2. It is the perspective view which looked at the grip nail 4 from another angle. FIG. 2 is a perspective view of a state in which a cylindrical workpiece 30 is clamped from the outside by a lathe chuck device 1. FIG. 2 is a perspective view of a state in which a cylindrical workpiece 30 is clamped from the inside by a lathe chuck device 1. It is a perspective view of the state which clamped work piece 30 without using grasping claw 4. This is an example of a conventional inner claw 51. This is an example of a conventional outer claw 52.

Explanation of symbols

  In the drawings, 1 is a lathe chuck device, 2 is a rotating disk, 3 is a master claw, 4 is a gripping claw, 5 is a lathe workpiece holding jig, 8 is a claw base, 11 and 20 are screw holes, 16 Reference numeral 17 denotes a concave groove, 19 and 27 insertion holes, 23 denotes a donut disk part, 24 denotes a back surface protrusion, and 25 denotes a surface protrusion.

Claims (1)

A rotating disk (2) that rotates integrally with the main shaft of the lathe is attached to three claw bases (8) that are attached at equal intervals in the circumferential direction and are simultaneously slid in the radial direction to grip the workpiece. A lathe work holding jig (5),
A master claw (3) fixed to each claw cradle with a bolt, and a grip claw (4) attached to the parent claw to grip a workpiece;
The parent claw is formed in a rectangular parallelepiped shape and is bolted to the claw base with its long side axis in the radial direction of the rotating disk. Each parent claw has the same shape and is fixed to the surface portion thereof. One or a plurality of arc-shaped concave grooves (16, 17) having a center of arc as the center of rotation of the rotating disk in a state where
Each of the gripping claws has the same shape, and is formed into a three-part donut disk shape (23) obtained by cutting the donut disk with a radial slit at three circumferentially-divided portions, and the back surface has an arc shape provided on the parent claw. An arc-shaped back projection (24) that fits into one of the concave grooves is provided with the center of the donut disk as the center of the arc, and the arc-shaped surface protrusion with the center of the donut disk as the arc center is also provided on the surface thereof. A protrusion (25) is provided, the inner side surface of the surface convex protrusion is processed with a radius of curvature that matches the outer peripheral surface of the workpiece having a cylindrical outer surface, and the outer side surface is the inner periphery of the workpiece having a cylindrical inner surface. Processed with a radius of curvature that fits the surface,
Each gripping claw is configured so that a fixing bolt is passed through an insertion hole (27) penetrating from the front surface to the back surface provided at an appropriate location, and is screwed and fixed to a screw hole (20) provided in each claw base. A workpiece holding jig for lathes.