JP2978743B2 - Manufacturing method of finger chuck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a finger chuck, and more particularly, to a method for manufacturing a finger chuck rotatably attached to a front end portion of a bar supply member of a bar feeder. Things.

[0002]

2. Description of the Related Art There is known an automatic bar feeder configured to automatically feed a relatively long bar to an automatic lathe such as an NC lathe. This type of bar feeder is provided with a bar feeder that feeds the bar to an automatic lathe, and the bar feeder feeds a bar such as a feed arrow that feeds the bar toward the automatic lathe. It includes a member and a supply member drive device including a drive motor, a chain, and the like. In general, the driving device applies a driving force or thrust (thrust force) in a forward direction to the bar supply member, and the bar supply member supplies the bar to the automatic lathe according to a product processing process of the automatic lathe.
A bar supply member of a bar supply machine generally includes a hollow cylindrical finger chuck for gripping a rear end portion of a bar as a workpiece or a material, and the finger chuck is provided at the front end or front end of the bar supply member. It is rotatably mounted on the part.
The rear end of the bar is inserted into the hollow portion of the finger chuck and is gripped by the finger chuck. Among such finger chucks, there is known a finger chuck having a structure provided with a bar holding member made of an elastic material. For example, the finger chuck disclosed in Japanese Utility Model Laid-Open No. 57-91502 has a cylindrical elastic body such as urethane resin, and the elastic body is lined around the entire inner wall of the hollow portion.
The rear end of the bar inserted into the finger chuck is elastically gripped. Similarly, the finger chuck disclosed in Japanese Utility Model Publication No. 7-4082 is provided with a cylindrical elastic gripping member, and the gripping member has a regular polygonal cross section for elastically gripping a rear end of a bar. Is provided.

[0003]

However, such an elastic body or elastic holding member (hereinafter referred to as an elastic holding member) is formed or processed separately from the finger chuck and processed in another manufacturing process. The finger chuck is inserted into the hollow portion of the finger chuck and is mounted in the hollow portion. Therefore, the manufacturing process of the finger chuck includes a forming operation and an assembling operation of the elastic gripping member, which not only complicates the whole, but also the elastic gripping member for gripping the rod material having a circular cross section is a rod material. Since the strict fitting tolerance between the rod insertion hole and the rod insertion hole is required, the molding accuracy of the inner peripheral wall of the rod insertion hole must be maintained and controlled extremely accurately, and therefore, excessively strict production control is required. . In addition, the elastic gripping member gripping a rod or the like having a circular cross-section particularly has an inner peripheral wall of the rod insertion hole due to a full surface contact between the inner peripheral wall of the rod insertion hole and the outer peripheral surface of the rear end of the rod. And the outer peripheral surface of the rear end portion of the rod material easily adheres. For example, during the operation and operation of a bar feeder that supplies a bar to an automatic lathe, the contact area between the bar and the bar insertion hole is dried due to lack of lubricating oil or machine oil, and the product processing process is stopped. In the final stage of the above, there may be a situation where it is difficult to pull out the remaining bar material from the finger chuck.

The present invention has been made in view of the above circumstances, and an object of the present invention is to simplify a manufacturing process and manufacturing management of a finger chuck having an elastic gripping member, and to reduce a rear end portion of a rod material. It is an object of the present invention to provide a method of manufacturing a finger chuck capable of smoothly and separably holding a finger chuck and a finger chuck.

[0005]

According to the present invention, in order to achieve the above object, in a method of manufacturing a finger chuck attached to a front end of a bar supply member, a plurality of recesses are gripped by the finger chuck. The bar is formed around the end of the bar to be inserted, and the bar is inserted into the bar insertion hole of the finger chuck to form a resin molding core in the bar insertion hole. The recesses are arranged at predetermined intervals in a circumferential direction of a resin molding core made of a bar. Further, the fluidized elastic resin material is injected into a gap formed between the outer peripheral surface of the core and the inner wall surface of the rod insertion hole, and the opening of the rod insertion hole is Is closed by a jig provided with a rod insertion hole through which the rod can be inserted. The inner wall of the rod insertion hole, the outer wall of the core, and the opening closing surface of the jig define a resin molding area in the rod insertion hole. According to the manufacturing method of the above configuration, the resin molding region is defined in the bar insertion hole, and the work or the workpiece (to be fed to the automatic lathe) is cured by curing the resin cast in the resin molding region. An elastic gripping member for gripping the rod is integrally formed on the inner wall surface of the rod insertion hole. The core is made of substantially the same bar as the workpiece or the workpiece, and the recess formed in the core forms a protruding portion that protrudes radially inward from the inner wall surface of the elastic holding member. When the bar feeder is used, the bar inserted into the bar insertion hole as a work or a workpiece is pressed by the outer peripheral surface of the rear end portion and compressed, and as a reaction, the projected portion is A bar gripper for elastically gripping the rear end of the bar by elastic restoring force is provided.

According to such a manufacturing method, since the elastic holding member is formed integrally with the rod insertion hole of the finger chuck, the forming operation and the assembling operation of the separate elastic holding member are omitted, and the finger chuck is omitted. Can be greatly simplified. In addition, in the above manufacturing method, since the bar to be gripped by the finger chuck is used as the resin molding core, maintenance and management of the molding accuracy of the elastic gripping member can be greatly simplified. Further, the projecting portion formed on the elastic gripping member is locally in contact with the outer peripheral surface of the rod inserted into the rod insertion hole as a workpiece or a workpiece with a gap in the circumferential direction. Therefore, the rear end portion of the bar inserted into the bar insertion hole can be relatively easily pulled out from the finger chuck. The present invention also provides a finger chuck provided with an elastic holding member integrally formed on the inner peripheral wall of the rod insertion hole by the above manufacturing method.

[0007]

According to a preferred embodiment of the present invention, a center hole is formed in a bottom wall of the rod insertion hole, and a center projection insertable into the center hole is provided at an end of the core. It is protruded. Preferably, the opening edge of the rod insertion hole is provided with a taper that expands forward, and the opening closing surface of the jig has a conical shape so as to complement the taper of the opening edge. Formed. Preferably, a similar taper that expands forward is formed on the front end surface of the elastic gripping member, and the taper of the circular opening edge and the taper of the elastic gripping member are:
A substantially continuous conical slope is formed. More preferably, the center of the center hole, the center of the center protrusion, and the apex of the conical closing surface are aligned on the center axis of the rod insertion hole. According to a further preferred embodiment of the present invention,
The recess is formed in the form of a groove extending in the axial direction of the finger chuck, and each groove has a predetermined angular interval in a circumferential direction,
For example, they are arranged at equal intervals at an angular interval of 60 degrees,
A plurality of ridges extending parallel to the central axis of the rod insertion hole are formed in the elastic holding member. Preferably, the diameter of the inner peripheral wall surface of the elastic gripping member substantially matches the diameter (outer diameter) of the bar as a workpiece, and the interval between the protruding ends of the opposing ridges is larger than the diameter of the bar. Is also set small. More preferably, the end of the groove of the core bends or inclines the end of the ridge radially outward to gradually reduce the amount of protrusion of the ridge.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2
FIG. 2 is a partial cross-sectional view and a cross-sectional view of the finger chuck according to the embodiment of the present invention. FIG. 1 shows the leading end or front end of the feed arrow 1 of a bar feeder (not shown). Feed arrow 1
Has a hollow portion 2 into which the rotating shaft 5 of the finger chuck 10 can be inserted. A needle bearing 3 that rotatably supports the rotating shaft 5 is provided in the hollow portion 2, and a thrust bearing 4 that rotatably supports the hollow chuck holding portion 6 is provided at the front end of the feed arrow 1. The reduced diameter base 11 of the finger chuck 10 is inserted into the opening of the chuck holding portion 6 that projects forward from the front end of the feed arrow 1.
The rotating shaft 5 passes through the thrust bearing 4 and
It is inserted into one hollow portion 12 and is integrally connected to the base 11 via a support shaft or a pin 13. The finger chuck 10 is formed entirely of a metal processing part or molded part, and includes a chuck body 14 extending forward from the base 11.
The chuck body 14 includes a center hole 15 formed at the center of the chuck body 14 and a bar holding portion 16 into which a bar W (a rear end is shown by a virtual line) as a work can be inserted. The bar holding portion 16 is formed in a hollow cylindrical shape, and has a circular opening edge 18 that opens forward, at the front end. The circular opening edge 18 is provided with a taper that expands forward. A substantially hollow cylindrical elastic member 20 is arranged on the inner peripheral wall of the hollow portion of the bar gripping portion 16, and the center axis of the elastic member 20 matches the central axis of the bar gripping portion 16. The elastic member 20 has a circular opening edge 22 opened forward at the front end. Similarly, a circular opening edge 18 having a taper that expands toward the front is formed at the front end of the bar holding portion 16, and the circular opening edges 18 and 22 are formed.
Form a substantially continuous conical slope.

The elastic member 20 is a molded product of an elastic resin such as urethane resin or rubber. As shown in FIG. 2, a plurality of ridges 23 spaced at a predetermined angular interval in the circumferential direction are formed on the elastic member 20.
Formed on the inner peripheral wall of the. In this example, the ridge 23 is 6
They are arranged at equal intervals with an angle interval of 0 degrees. The ridges 23 slightly protrude from the inner peripheral wall of the elastic member 20, and extend in parallel with the center axis of the elastic member 20 and the rod holding portion 16. The diameter D of the inner peripheral wall surface of the elastic member 20 is substantially equal to the diameter (outer diameter) of the bar W as a workpiece or is set slightly larger than the diameter of the bar W. Is smaller than the diameter of the bar W. As shown in FIG. 1, the elastic member 20 has an inclined surface 26 near the bottom wall 19 of the rod insertion hole 17, and the ridge 23 is
6 extends forward just before the circular opening edge 22. Ridge 2
3 is set substantially constant over the entire length,
The front end 24 of the ridge 23 is bent or inclined radially outward to gradually reduce the amount of protrusion. When the rear end of the bar W is inserted into the bar insertion hole 17 of the bar gripper 16, the bar W
Is inserted into the hollow portion 21 of the elastic member 20 while being pressed by the front end 24 of the ridge 23 and compressing the front end 24 and the ridge 23 outward in the radial direction. It contacts the bottom surface (bottom wall 19) of the rod insertion hole 17. Compressed ridge 2
Numeral 3 elastically grips the outer peripheral surface of the bar W by an elastic restoring force acting in a direction protruding inward in the radial direction, and restrains the rear end of the bar W in the bar grip 16.

FIG. 3 is a longitudinal sectional view showing a method of manufacturing the finger chuck shown in FIGS. 1 and 2, and FIG.
It is a perspective view of the bar WC shown in FIG. Referring to FIG. 3 and FIG.
A molding method or a manufacturing method will be described. Made of metal molded or processed into a predetermined shape (for example, SUS304)
As shown in FIG. 3, the finger chuck 10 is fixed to an upright position with the circular opening edge 18 of the bar holding portion 16 facing upward. A rod material WC of a predetermined length processed into a predetermined shape,
It is inserted vertically into the hollow portion of the bar holding portion 16. Bar W
C is a bar cut piece having the same cross-sectional shape, diameter, and material as the bar W (FIG. 1) as a workpiece or a material to be gripped by the finger chuck 10, and is cut into a relatively short predetermined length. I have. The lower part of the bar WC is cut into a predetermined shape as shown in FIG. 4, and has a central projection 41 at an axis center position and a plurality of grooves 4 extending from the lower end surface in parallel with the axis.
2 and a chamfered portion 43 extending over the entire periphery of the lower end surface. The diameter (outer diameter) of the center projection 41 is set substantially equal to the diameter (inner diameter) of the center hole 15 of the finger chuck 10, and the angular interval, shape, length, width and depth of the groove 42 are formed by molding. The angular interval, shape, length, width, and height of the ridge 23 of the elastic member 20 to be set are set to be substantially the same.

[0011] As shown in FIG.
The center projection 41 of the bar WC inserted vertically into the inside is further inserted into the center hole 15 of the finger chuck 10.
Since the center axis of the center projection 41 inserted into the center hole 15 is aligned with the center axis of the finger chuck 10, the bar WC is accurately positioned at the center of the finger chuck 10. A fluid resin material such as a fluidized urethane resin is injected into the hollow portion of the rod holding portion 16. The resin material is cast around the bar WC, and the bar holding portion 16 is filled with the resin material up to near the upper edge (circular opening edge 18).
A steel jig 30 through which the bar WC can be inserted is vertically mounted on the finger chuck 10. A jig 30 molded or processed with a BSBM material or the like includes a cylindrical main body portion 31 having a rod material insertion hole 33 through which the rod material WC can be inserted in a loosely fitted state, and a circular opening edge 18 of the rod material gripping portion 16. Conical bottom 3 complementary to
2 is provided. The inclination angle of the bottom surface 32 is
Of the bottom surface 3
The vertex of the second cone is located on the center axis of the jig body 31. Jig 30 placed on the inclined surface of circular opening edge 18
Is positioned substantially at the axis of the finger chuck 10 by the rod WC inserted into the rod insertion hole 33, and the axis of the finger chuck 10 is determined by the inclination angle of the circular opening edge 18 and the weight of the jig 30 itself. The position is self-centered (self-centering).

Thus, the bar WC and the jig 30 are centered on the center axis of the finger chuck 10 and aligned with the center of the finger chuck 10. A peripheral wall and a bottom wall of the hollow portion of the bar holding portion 16; an outer surface of the bar WC;
The bottom surface 32 forms a cavity in which the resin can be filled in the bar holding portion 16, and the resin poured into the hollow portion of the bar holding portion 16 hardens in the cavity. The jig 30 and the bar WC are pulled up after the resin in the cavity is cured, and the elastic member 20 (FIGS. 1 and 2) integrally formed in the bar grip 16 by the mold opening process. ) Is exposed in the rod insertion hole 17. According to the above-described manufacturing method, a resin molding cavity is defined in the rod insertion hole 17, and a workpiece or a workpiece to be fed to an automatic lathe by curing of the resin cast in the resin molding cavity. Elastic holding member 20 for holding a bar W as a member
Are integrally formed on the inner wall surface of the rod insertion hole 17. The resin molding core or the molding core formed by the bar cut pieces WC is made of substantially the same bar as the bar W, and the groove 42 formed in the core has a protrusion projecting inward in the radial direction. Article 23
Is formed on the inner wall surface of the elastic holding member 20.

When the bar feeder is used, the bar W inserted into the bar insertion hole as a work or a workpiece is pressed by the outer peripheral surface of the rear end portion of the protrusion 23 to be compressed. The ridge 23 elastically grips the rear end portion of the bar by an elastic restoring force acting as a reaction. Therefore, since the elastic holding member 20 is integrally formed with the rod insertion hole 17, the forming operation and the assembling operation of the elastic holding member 20 are omitted, and the manufacturing process of the finger chuck 10 is greatly simplified. Moreover, in the above-described manufacturing method, the cut pieces WC of the bar W to be gripped by the finger chuck 10 are used as the resin molding core, so that the maintenance and management of the molding accuracy of the elastic gripping member 20 are greatly simplified. be able to. Further, the protrusions 23 formed on the elastic holding member 20 locally contact the outer peripheral surface of the rod W inserted into the rod insertion hole 17 at intervals in the circumferential direction. The rear end portion of the bar inserted into the insertion hole 17 can be relatively easily pulled out from the finger chuck.

[0014]

As described above, according to the above configuration of the present invention, the manufacturing process and manufacturing management of the finger chuck provided with the elastic holding member are simplified, and the rear end of the bar and the finger chuck are made smooth. It is possible to provide a method of manufacturing a finger chuck which can be separably gripped.

[Brief description of the drawings]

FIG. 1 is a side view of a finger chuck according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the finger chuck shown in FIG.

FIG. 3 is a longitudinal sectional view showing a method of manufacturing the finger chuck shown in FIGS. 1 and 2.

FIG. 4 is a perspective view of the bar shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Feeding arrow 10 Finger chuck 11 Base 14 Chuck main body 15 Center hole 16 Bar gripping part 17 Rod insertion hole 18 Circular opening edge 20 Elastic member 23 Ridge 30 Jig 31 Cylindrical strip main body part 32 Conical bottom surface 33 Rod insertion Hole 41 Center projection 42 Groove 43 Chamfered part W Bar (work or workpiece) WC Bar (core)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B23B 13/02 B25G 1/10 F16B 7/00

Claims (7)

(57) [Claims] 1. A method of manufacturing a finger chuck attached to a front end of a bar feeder of a bar feeder, wherein a plurality of recesses are formed on an outer periphery of an end of the bar to be gripped by the finger chuck. The material is inserted into the rod insertion hole of the finger chuck to form a resin molding core, and the fluidized elastic resin material is formed between the outer peripheral surface of the rod and the inner wall surface of the rod insertion hole. While filling the gap, the jig provided with a rod insertion hole through which the rod can be inserted, closing the opening of the rod insertion hole, the inner wall of the rod insertion hole,
The outer wall of the core and the closing surface of the opening of the jig define a resin molding region in the rod insertion hole, and the recesses are spaced at predetermined intervals in a circumferential direction of the resin molding core. A method for manufacturing a finger chuck, wherein the finger chuck is arranged. 2. The recess according to claim 1, wherein the recess is formed in a shape of a groove extending in an axial direction of the finger chuck, and the grooves are arranged at equal intervals in a circumferential direction of the core. 3. The method for manufacturing a finger chuck according to item 1. 3. A center hole is formed in a bottom wall of the rod insertion hole, and a center protrusion insertable into the center hole is provided at an end of the core. Or the manufacturing method of the finger chuck of Claim 2. 4. An opening edge of the bar insertion hole is provided with a taper which is widened outward, and an opening closing surface of the jig is conical so as to complement the taper of the opening edge. The method for manufacturing a finger chuck according to claim 1, wherein the finger chuck is formed in a shape. 5. A center hole is formed in a bottom wall of the bar insertion hole, and a center projection insertable into the center hole is provided at an end of the core, and an opening edge of the bar insertion hole is provided. The jig has an opening closing surface formed in a conical shape so as to complement the taper of the opening edge, and the center of the center hole, the center of the center hole, The method according to claim 1, wherein a center of the projection and a vertex of the conical closing surface are aligned on a center axis of the rod insertion hole. 6. Each groove of the core has a substantially uniform depth over substantially the entire length, and the ends of the groove are curved such that the depth of the groove is gradually reduced. The method for manufacturing a finger chuck according to claim 2, wherein the end portion of the protrusion formed on the molding resin is gradually reduced by the groove. 7. A finger chuck manufactured by the manufacturing method according to claim 1.