JPH09309024A - Broach tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To release elastic deformation during cutting even in end face working of a round bar of small diameter and an elastic part such as using a thin plate material so that molding can be accurately made, by providing a non-cutting interval suspending cutting at least over a cutting length or more of a workpiece in a drawing process. SOLUTION: In a broach tool having a series of cutting edge rows in a main unit 1, for instance, in a row of semifinish edge 3, a dummy cutting edge 6 is provided as a non-cutting interval suspending cutting at least over a cutting length or more of a workpiece. In this way, after cutting by a rough edge 2 and the semifinishing edge 3, in a part of the dummy cutting edge 6, deformation at cutting time is released, flatness is restored, further advancing to the semifinishing edge 3 can be made from a stable condition. Accordingly, accurate machining of small influence by deformation can be performed, machining accuracy is also improved. Local wearing of a cutting edge due to vibration of the workpiece, particularly wearing generated in a cutting edge flank is reduced, a long life can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding broaching tool used in a broaching machine, and more particularly to a molding broaching tool used for molding a part which is easily elastically deformed by a cutting force. It relates to a chi tool.

[0002]

2. Description of the Related Art A broaching tool is generally provided with a cutting edge row consisting of a large number of cutting edges arranged on a long body so that the height of the cutting edge is increased successively. It consists of a rough blade, a medium finish blade, and a finishing blade. Each cutting edge from the first blade, which is a rough blade, to the finishing blade at the final part, is arranged in association with the cutting length of the workpiece so that one or more cutting edges always perform a cutting action, Positioning the workpiece along the guide part, from the rough blade to the finishing blade, it is possible to obtain a highly accurate contour shape by moving the tool in a short distance with roughly one movement, and it is possible to manufacture highly compatible mass-produced parts. It has characteristics. Although a cutting force corresponding to the machining allowance is applied during machining, there is a problem that precision is difficult to maintain in machining a component that has low rigidity and is prone to elastic deformation.
As exemplified by No. 88 (hereinafter referred to as a conventional product), a means such as a non-cutting portion for recovering elastic deformation due to cutting resistance is provided between the rough blade of the helical blade and the finishing blade of the ring blade. There was something that was taken.

[0003]

However, in the conventional broaching tool, if the workpiece itself is rigid, smooth cutting can be performed according to the cutting force, but the end face machining of a small-diameter round bar and thin machining are possible. When processing an elastic material such as a plate material, there has been a problem in that the processing material is elastically deformed by the cutting force, chattering occurs, and the processing accuracy is impaired. In addition, in the case of thin plate materials and the like, from the viewpoint of productivity, it is often desired that a plurality of workpieces be machined in one motion at the same time, which tends to further prolong the machining deformation. The present invention has been made under the background as described above, and by arranging a cutting edge so that the cutting is temporarily interrupted during the cutting process, it is possible to use the end face processing of a small diameter round bar or the thin plate material. It is an object of the present invention to provide a broaching tool capable of releasing an elastic deformation during cutting even if such an elastic component is used, and enabling accurate molding.

[0004]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a broaching tool having a body of a series of cutting edges for cutting at least a workpiece during one drawing process. It is provided with a non-cutting section that interrupts cutting over a long period. Further, it is characterized in that a pseudo cutting edge serving as a guide is provided in the non-cutting section.

[0005]

By applying the present invention, cutting is performed with a large cutting amount up to the state where the intermediate finishing margin is left, and the deformation during cutting is released in the non-cutting section to recover the flatness and stabilize the stability. Since it is possible to proceed from the state described above to the intermediate finishing and finishing steps, the cutting force applied to the finishing step in the latter half can be suppressed to a low level, and accurate machining with little influence of deformation can be performed. Unlike conventional products, a middle finishing blade is also provided in the finishing process of the latter half, and the first half and the latter half are the same single unit, so the working accuracy of the broach tool itself can be improved, and therefore the work accuracy is also improved. It can be done. If the cutting can be performed in such a stable state, the local wear of the cutting edge due to the vibration of the workpiece due to the cutting force, especially the wear on the flank of the cutting edge can be reduced, and the need to re-grind the flank is reduced. As a result, a long life is obtained. Here, in the case of a horizontal broaching machine or in the case where the workpiece has an unstable shape, there may be a displacement due to the weight of the workpiece if there is a non-cutting section. Therefore, it is effective to provide a pseudo cutting edge that serves as a guide without having a cutting edge.
The pseudo cutting edge may be provided with a plurality of pieces having the same shape as the cutting edge and having only the height of the cutting edge reduced, or may be one in a non-cutting section continuously. Hereinafter, the present invention will be described with reference to the drawings showing the embodiments.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a surface blower according to an embodiment of the present invention.
1 is the main body. The main body 1 is made of powder HSS and has a finishing blade with a width of 38 mm and a length of 440 mm.
Equipped with a single cutting edge. Generally, the number and pitch of cutting edges are determined by the cutting length of the workpiece, and are composed of a rough blade, a semi-finishing blade, and a finishing blade, but in the present invention, the purpose is to cut the end face of a thin rod-shaped workpiece. Therefore, next to 37 rough blades 2 and 12 intermediate finishing blades 3, 5 pseudo cutting blades 6 are provided as a non-cutting section 4, and then the intermediate finishing blades 3 and 5 finishing blades are again provided. 5 is provided. Incidentally, the non-cutting section 4 has a cutting edge of about 0.1 mm lower than the front and rear intermediate finishing blades so as to serve as a guide for maintaining the position of the workpiece.

The workpiece is a motor rotation shaft made of S45C, the round shaft portion of which is gripped and the flat drive flat at the end thereof is cut. In the case of using a broach consisting of rough blades, intermediate finishing blades and finishing blades up to now, the shape may not be finished correctly due to deformation or burr occurrence during cutting, whereas According to the broaches of the present invention, an excellent finished surface was obtained, and the broach was finished to a predetermined accuracy. Although the surface broaching example was given here, the same effect can be obtained in the case of other low-rigidity workpieces such as round holes for ring-shaped parts and spline holes for thin disk-shaped parts. It recognized.

[0009]

As described above, according to the present invention, as a result of the improvement in the broach used for the molding process of the part which is liable to be elastically deformed by the cutting force, an excellent finished surface can be obtained with high accuracy. It became possible to cut.

[Brief description of drawings]

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

FIG. 2 is a plan view of FIG.

FIG. 3 is a partial view showing a machining position of a workpiece to be cut in the embodiment of FIG.

FIG. 4 shows a shape of a non-cutting section, showing a state of a plurality of pseudo cutting blades.

FIG. 5 shows a shape of a non-cutting section, showing a case having one pseudo cutting blade.

FIG. 6 shows a shape of a non-cutting section, showing a case without a pseudo cutting blade.

FIG. 7 is an explanatory diagram of a cutting dimension showing a relationship between a blade number of a cutting edge of a normal broaching tool and a height dimension of the cutting edge.

FIG. 8 is an explanatory diagram of a cutting dimension showing a relationship between a blade number of a cutting edge and a height dimension of the cutting edge of the broach of the present invention.

FIG. 9 is a front view showing an example of a conventional product.

[Explanation of symbols]

 1 Main Body 2 Rough Edge 3 Medium Finishing Edge 4 Non-Cutting Section 5 Finishing Edge 6 Pseudo Cutting Edge 7 Workpiece 8 Cutting Length h Step between Cutting Edge and Pseudo Cutting Edge

Claims (2)

[Claims] 1. A broaching tool having a series of cutting edge rows in a main body, wherein a non-cutting section for interrupting cutting for at least a cutting length of a workpiece is provided during one drawing process. Broaching tool. 2. The broaching tool according to claim 1, wherein
A broaching tool, characterized in that a pseudo cutting edge serving as a guide is provided in the non-cutting section.