JP2008296331A - Processing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machining device suppressing facility cost and saving on labor during production. <P>SOLUTION: The outer periphery Sb of a screw shaft S is cut in a shaft member W by an insert tip 3B, and a screw groove Sa is cut in the shaft member W by an insert tip 3A. Since there is no need for machining a flange or finishing the outer diameter thereof in the pre-machining as in a prior art, the facility cost is suppressed, and the labor for manufacturing the screw shaft can be saved on. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a machining apparatus capable of machining a thread groove of a ball screw mechanism.

Conventionally, as a method of cutting a screw shaft of a ball screw mechanism, a method of cutting a screw groove using a lathe using an overall shape tool formed into a groove shape, and a Waring (Mach) as shown in Patent Document 1 There are a method of cutting a screw shaft using an apparatus, and a cutting method of copying a screw shaft along a minute division point group using an NC lathe as shown in Patent Document 2.
JP-A-10-58233 Japanese Patent Laid-Open No. 02-180523

  By the way, the screw shaft of the ball screw mechanism is not only a screw groove formed on the outer periphery, but the outer diameter (land portion height) of the screw shaft is precisely processed, and a flange for attaching to other members. In many cases, it is necessary to machine the parts with high accuracy. However, in any of the above-described processing methods, it is necessary to form a flange portion or the like in the material in advance and to finish the outer diameter before processing the thread groove. It was necessary to install the processing equipment for finishing the outer diameter separately, which resulted in an increase in equipment cost and labor for manufacturing. In addition, since two or more processing steps are included, it is necessary to manage semi-finished products in the middle of processing, and it is difficult to perform process integration for dealing with small lot products.

  The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a processing apparatus that can reduce equipment costs and save labor during manufacture.

The processing apparatus of the present invention is a processing apparatus that forms a screw shaft of a ball screw mechanism by cutting a shaft member.
A rotating body that moves relative to the shaft member in the axial direction and the rotational direction;
A plurality of cutting tools attached to the rotating body,
A portion of the shaft member other than the thread groove is cut by one of the cutting tools, and a thread groove of the shaft member is cut by the rest of the cutting tool.

  According to the present invention, one of the cutting tools cuts the shaft member at a portion other than the thread groove, and the remaining cutting tool cuts the thread groove on the shaft member. Thus, it is not necessary to process the flange or the like in the pre-processing as described above, or to finish the outer diameter, the equipment cost can be suppressed, and the labor for manufacturing the screw shaft can be saved.

  The part other than the screw groove is preferably the outer periphery of the screw shaft, and further preferably, the screw groove is cut on the outer periphery of the screw shaft.

  The site other than the screw groove is preferably a step portion of the screw shaft.

  It is preferable to have a guide bush that holds the shaft member with respect to the frame and moves together with the rotating body because chatter during cutting can be suppressed.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a main part of a processing apparatus according to the present embodiment, FIG. 2 is a diagram of the configuration of FIG. 1 viewed in the direction of arrow II, and FIG. FIG. 4 is a front view of the tool holder cut along the line III, FIG. 4 is a front view of the tool holder, and FIG. 5 is a view taken along the line VV and viewed in the direction of the arrow. 6 is a view of the configuration of FIG. 4 taken along the line VI-VI and viewed in the direction of the arrow.

  In FIG. 4, a substantially annular tool holder 1 which is a rotating body has an opening 1a at the center and a pair of recesses 1b and 1b cut into shallow grooves at point-symmetric positions. Concave

  The two rectangular plate-shaped tools 2 each have a long hole 2a. An insert tip 3A is attached to the end of one bit 2, and an insert tip 3B is attached to the end of the other bit 2, and they are joined together. Note that any combination of the cutting tool and the insert chip is possible, which has the effect of reducing the processing time.

  As can be understood by comparing FIGS. 5 and 6, the insert tip 3A and the insert tip 3B have different blade shapes. More specifically, the cutting edge of the rake face 3a of the insert tip 3A has an arc shape so that the thread groove of the screw shaft of the ball screw mechanism can be formed, and the cutting edge of the rake face 3b of the insert tip 3B is the screw axis. It has a flat-tip shape so that the outer periphery of can be formed. The center of the insert tip 3A is shifted to the back side by a distance Δ with respect to the position of the insert tip 3B. The distance Δ is preferably 1.5 times the lead of the thread groove of the screw shaft.

  As shown in FIG. 4, the two cutting tools 2 are respectively disposed in the recesses 1 b of the tool holder 1 and are fixed to the tool holder 1 by bolts 4 and 4. Before being fixed by the bolts 4 and 4, guided by the parallel side surfaces of the recess 1b, the cutting tool 2 can be relatively moved in the left-right direction in FIG. In the present embodiment, the tool holder 1 is not provided with an inclination mechanism for changing the inclination of the insert tips 3A and 3B.

  As shown in FIGS. 1 and 3, the outer periphery of the shaft member W, which is a material for the screw shaft, is supported by a hollow guide bush 5 formed by coating super steel with DLC (diamond-like carbon). The guide bush 5 is fitted to the frame 6. It is important that the guide bush 5 and the shaft member W are always held at an appropriate gap. However, the shaft member W may be held at an appropriate pressure using hydraulic pressure (pneumatic pressure) or the like. good.

  Next, processing of the screw shaft of the ball screw mechanism will be described. The tool holder 1 and the cylindrical shaft member W are attached to separate spindles of a lathe with the axes shifted from each other. At this time, the extended surface of the rake face 3a of the insert tip 3A is orthogonal to the axis of the shaft member W. Accordingly, the cutting of the thread groove is an interference cutting and has a dedicated shape. However, a tilting mechanism for tilting the tool holder 1 by the lead angle may be provided. The cutting edge of the insert tip 3A is at a position for cutting the surface of the shaft member W, and the cutting edge of the insert tip 3B is at a position for cutting the thread groove of the screw shaft.

  In this state, as shown in FIG. 1, the tool holder 1 and the shaft member W supported by the frame 6 are relatively moved while rotating in the same direction. It is faster than the rotation speed of W. Further, the tool holder 1 is moved in the axial direction in synchronization with the guide bush 5 after the start of cutting. At this time, the insert tip 3B starts cutting of the outer periphery of the screw shaft in advance, and the insert tip 3A cuts the screw groove with respect to the cut outer periphery after being delayed by a distance Δ. . Since the shaft member W is held by the guide bush 5 that moves in synchronization with the tool holder 1, a position that is a fixed distance away from the thread groove machining point is always supported, so that the outer periphery of the screw shaft is cut. The chatter phenomenon (vibration of the shaft member W during cutting of the insert tip 3A) that occurs due to insufficient rigidity of the shaft member W that has become thinner can be suppressed.

  When the tool holder 1 is moved relative to the shaft member W to a predetermined axial position and then the processing is terminated, a shape as shown in FIG. 7 can be formed. Here, in FIG. 7, the screw shaft S is formed with the thread groove Sa cut by the insert tip 3A, and at the same time, the outer periphery (land portion) Sb of the screw groove Sa cut by the flat tip of the insert tip 3B. And the step part Sc of the thread groove Sa cut | disconnected by the side edge of the insert chip 3B is formed. As shown in FIG. 6, the stepped portion Sc is spaced from the end portion of the thread groove Sa by a distance Δ (for example, 1.5 leads). Therefore, the stepped portion Sc can be used for attaching the screw shaft S. A flange portion may be formed instead of the stepped portion Sc. Thereafter, the screw shaft S is heat-treated to obtain a product as shown in FIG. 8, and can be incorporated into a ball screw mechanism (not shown).

  According to the present embodiment, the insert tip 3B is used to cut the outer periphery Sb of the screw shaft S on the shaft member W, and the insert tip 3A is used to cut the screw groove Sa on the shaft member W. Unlike the technology, it is not necessary to process the flange or the like in the pre-processing or finish the outer diameter, the equipment cost can be reduced, and the labor for manufacturing the screw shaft S can be saved.

  The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate. For example, the shaft member W may be solid or hollow (tubular).

It is a principal part perspective view of the processing apparatus which is this Embodiment. It is the figure which looked at the structure of FIG. 1 in the arrow II direction. It is the figure which cut | disconnected the structure of FIG. 2 by the III-III line | wire, and looked at the arrow direction. It is a front view of a tool holder. It is the figure which cut | disconnected the structure of FIG. 4 by the VV line and looked at the arrow direction. It is the figure which cut | disconnected the structure of FIG. 4 by the VI-VI line and looked at the arrow direction. It is the figure which cut | disconnected the axial part of the screw shaft of the ball screw mechanism, and expanded a part. It is a figure which shows the state in the middle of the process of the screw shaft of a ball screw mechanism. It is a side view of the completed screw shaft of a ball screw mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tool holder 1a Opening 1b Recessed part 2 Byte 2a Long hole 3A Insert chip 3B Insert chip 3a Rake face 3b Rake face 4 Bolt 5 Guide bush 6 Frame S Screw shaft Sa Screw groove Sb Outer circumference Sc Step W Shaft member

Claims (4)

In a processing apparatus for forming a screw shaft of a ball screw mechanism by cutting a shaft member,
A rotating body that moves relative to the shaft member in the axial direction and the rotational direction;
A plurality of cutting tools attached to the rotating body,
A machining apparatus characterized in that a portion other than the thread groove is cut on the shaft member with one of the cutting tools, and a thread groove is cut on the shaft member with the rest of the cutting tool.   The processing apparatus according to claim 1, wherein the portion other than the screw groove is an outer periphery of the screw shaft.   3. The processing apparatus according to claim 1, wherein the portion other than the thread groove is a step portion of the screw shaft.   The processing apparatus according to claim 1, further comprising a guide bush that holds the shaft member with respect to a frame and moves with the rotating body.

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