JPH0428481B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cutting off bar material, and in particular takes measures against protrusions that occur at the center of the end face of the product when cutting off the product from the raw bar material.

The conventional method for cutting off bar material is as shown in Fig. 1 A, B, and C. The holder D of product C is attached to the tool rest facing the spindle side B that holds and rotates bar material A, and the parting tool E is used. When cutting off the bar material, the holder D moves forward in the direction of the arrow in Figure A, and the parting tool E cuts off the product C and the base material of the bar A. Reference) has a small cross-sectional area at the joint between product C and bar material A, making it weak against twisting and eventually breaking. This remains on the product as a protrusion F (Fig. 1 B, C,
(See d and e). Therefore, the protrusion F is usually removed using a secondary processing machine or manually.

In other words, in this conventional bar material cutting method, the shape of the product that can be held is determined by the outer diameter clearance with the holder and the length of the product. In addition, protrusions occur due to the product tilting when cutting off, or due to friction between the product and the holder, resulting in a difference in rotation between the bar material and the product. It is necessary to grasp the product to prevent it from tipping over, and to rotate the bar material and the product using a synchronous motor, etc. to eliminate the rotation difference between the product and the bar material. Therefore, there was a problem in that extra steps such as manual removal of protrusions were added.

The present invention has been made in view of these conventional problems, and involves forming a concave portion around the protrusion F by relatively moving the parting tool in the radial direction and the axial direction before the end of the parting. This prevents the protrusion F from protruding beyond the end surface of the product.

Hereinafter, the present invention will be explained based on the drawings.

FIGS. 2 and 3 are diagrams explaining one embodiment of the present invention.

First, to explain the configuration, a cut-off tool 10 is attached to a tool rest 18 of the equipment, and a product holder 12 which serves as a discharger for a product 11 is attached to a product holder holder 13. The discharge/product holder 12 moves forward during cutting off and retreats when cutting off is completed.

In the figure, 14 is a bar material, 15 is a chuck/guide bush, and 18 is a tool rest of the cutting tool 10.

The parting tool 10 has a shape in which the cutting blade at the tip thereof is inclined with respect to the axis of the bar material 14, and the end thereof on the product 11 side forms an acute angle and projects toward the product 11 side.

Incidentally, the discharge/product holder 12 can be of a fixed type or a rotary type.

This method is mainly suitable for products that do not have internally machined parts.

Next, the effect will be explained.

The bar material 14 is held by a chuck on the spindle side, passes through a chuck/guide bush 15 (some equipment does not have a guide bush), and is ejected and fixed by the chuck on the spindle side to a processing point, and is rotated. Then, the necessary machining of the workpiece is performed, and during the cut-off process, the discharge/product holder 12 mounted on the product holder table 13 moves forward to hold the product while cutting it off (Fig. 3, I, B,
(See C, D). Cutting part-time job 1 before finishing cutting
0 in the axial direction (see the dotted line arrows indicating the bite movements in Figure 3 B, C, and D), the protrusions that have conventionally occurred are scraped away to form them in the concave portion 17 of the product, and the protrusions are removed from the end surface of the product. This eliminates protrusion.

In Fig. 3C, the product and the bar material are separated, and at the same time, the product 11 is pushed into the ejection/product holder 12.Then, the ejection/product holder 12 retreats as shown in D, and the end face of the bar material is also ground and finished. . Sections 17 in E and F of Figure 3 are examples of the structure of the concave portion formed on the end face of the product center. Note that 16 is a protrusion.

As explained above, the present invention provides relative movement in the radial and axial directions to the parting tool after the product is held by the ejection/product holder, thereby removing the protrusion that conventionally occurs during parting into the end surface of the product. This can be easily eliminated to ensure a constant product length, and is effective in significantly improving work efficiency in simple equipment.

[Brief explanation of drawings]

Figures 1A to 3E are explanatory diagrams of the conventional processing method and products, Figures 2 and 3 are explanatory diagrams of the embodiment of the present invention, Figure 2 is an enlarged cross-sectional view of the main processing parts, and Figures 3A to 3E are explanatory diagrams of the conventional processing method and product. is an explanatory diagram of processing steps and products. 10...Cut-off part-time job, 11...Product, 12...
...Discharge and product holder, 13...Product holder stand, 1
4...Bar material, 15...Chuck/guide bush, 16...Protrusion, 17...Concave portion, 18...
The turret.

Claims (1)

[Claims] 1. A product holder that fixes and rotates a bar material on a rotating main shaft, has a cutting tool and a turret for cutting a product from the bar material, and is equipped with a discharge/product holder that moves until it holds the product. In a processing machine having a tool stand, the parting blade at the tip is inclined with respect to the axis of the bar material, and the end of the parting blade on the product side forms an acute angle and protrudes toward the product side. Using a cutting tool, after the ejecting and product holder holds the product, the parting tool is first moved in the radial direction to perform parting, and before the parting is completed, the parting tool is moved in the radial and axial directions. Parting off of bar material characterized by providing relative movement and forming a concave part on the outer periphery of the protrusion that is generated on the end face of the product at the end of the parting, thereby preventing the tip of the protrusion from protruding from the end face of the product. Processing method.