JPH04258305A - How to modify carbide rolls - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for modifying a cemented carbide roll (a cemented carbide roll) used for rolling pipes, etc., and a cutting tool used in the method.

0002

2. Description of the Related Art Carbide rolls used for rolling round pipes and the like are made by combining a plurality of roll bodies having arcuate rolling grooves so that a circular space for forming is created between them. If the circular space at this time has an irregular shape, the roundness of the rolled product will deteriorate. Therefore, after manufacturing or repairing this type of roll, the rolling grooves are re-sharpened in the same state as when it was rolled.

[0003] Conventionally, regarding this modification, the outline of the chip is transferred to the roll by feeding a cutting tool with a disc-shaped sintered diamond chip into the roll that is set in a rolling state and rotated in one direction. There was a method (disc bite method), but this method was limited by the manufacturing limit of sintered diamond chips, and the maximum length was 50 m.
It can only be machined up to a diameter of about m, and the tool cost is high because it uses a large sintered diamond.

Therefore, as a countermeasure, the number of cutting blades equal to the number of rolls in one set is arranged at a constant pitch in the circumferential direction, and while being fed in one direction along a circle concentric with the central axis between the rolls, the cutting blades are cut into the rolling groove. The idea was to cut from one end to the other. According to this method, only a small cutting edge tip is required. Furthermore, since the distance from the center between the rolls to the cutting edge of the chip can be freely set, there is no restriction on the machining diameter due to the size of the chip. However, this method had the following problems that hindered its practical application.

[0005]

[Problem to be solved by the invention] There is no problem with the method of applying feed to the cutting edge to scrape the groove surface from one end because sufficient roll thickness is ensured in the feed direction at one end, but Machining at the other end, where the remaining roll thickness is insufficient, is not successful.

That is, when the cutting allowance is large, the cutting resistance also becomes large. Further, at the other end where the cutting blade cuts through, a feed component force acts in the tensile direction. However, cemented carbide has lower toughness than steel etc., and is strong against compressive force but weak against tensile force. Therefore, if the cutting allowance is large, the other end will not be able to withstand the cutting force and the roll will chip.

[0007]

[Means for Solving the Problems] In order to eliminate the above-mentioned problem of chipping, the present invention arranges the same number of cutting blades as the number of set rolls at equal pitches in the circumferential direction, and uses these cutting blades to roll the rolls. First, cut the grooved surface part way from one end to the other, then reverse the feeding direction of the cutting blade and use the same blade to cut the uncut part of the grooved surface of the adjacent roll from the other end to one end. do.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in further detail with reference to the accompanying drawings. In FIG. 1, a roll holder 5 is attached to a main shaft 2 of a lathe 1, a tool feeding device 4 is provided on a feeding table 3, and a cutting tool 10 is mounted on the main shaft of this device.

The tool 10 has a cylindrical body 1 shown in FIG.
1 has a shank 12 (FIG. 2) at the rear thereof. A seat groove 13 is provided on the outer periphery of the tip of the main body 11 at an indexing angle of 120 degrees in the illustrated example.
A cassette 15 having a circular sintered diamond cutting tip 14 attached thereto so as to be clampable and unclampable is mounted in each of the seat grooves. FIG. 3 shows how the carbide rolls 6, 7, and 8 are attached to the roll holder 5.

In FIG. 1, when the tool 10 is fed in the Z-axis direction in FIG. 2, the cutting allowance of the roll is set. At this time, the roll is already driven and rotating. The tool 10 is fed so that the chip 14 is between the rolls, that is, at the position (a) in FIG. 1 (the other two chips are omitted from this figure). Then, rotate this tool 10 so that each chip 1
The cutting edge 4 is cut into the rolls 6, 7, and 8, and the groove surface of the rolling groove 9 is cut by feeding until the tip 14 is at the position (b).

Next, when the cutting progresses to section (B), the feed is stopped, the tool is reversed, and the tip 14 is returned to the cutting starting point. Furthermore, after returning to part (A), the rotation in the return direction is continued, and the chip processed on the roll 6 is now cut into the roll 7, and the uncut portion of the rolling groove of the roll 7 is cut from the other end side by reverse feeding. Continue cutting. Although not shown in the figure, other chips are processed in the same way from one end to the other, so
When the chips shown in FIG. 1 reach the part (C), the modification of all the rolls is completed.

Note that the feeding of the chip 14 in FIG.
First, it is rotated by 60 degrees, then returned by 60 degrees, and further rotated by 60 degrees in the returning direction, but the rotation angle of 60 degrees is not absolute. If the processing is completed at a position rotated approximately 10 degrees from the end of the rolling groove, chipping of the roll will not occur. The only difference is whether the amount of machining increases in the first feed or the amount of machining increases in the return rotation, and there is no difference in machining time. The experimental results are described below.

The tool shown in FIG. 4 is a combination of three cemented carbide rolls made of WC-11.5 wt% Co cemented carbide, set on a lathe for modification, and equipped with a circular sintered diamond cutting tip with a diameter of 14 mm. The rolling groove was revised. The processing conditions at this time were: roll peripheral speed 6 m/min, feed 0.2
mm/rev (feed per rotation of roll), depth of cut 0
．． 6 mm, and water-soluble cutting oil was used.

[0014] When machining was continued in the same direction, a chip appeared on the cut-out side of the roll, but when the process of the present invention was performed and the operation shown in Fig. 1 was carried out, the chip was removed. This did not occur at all, and the feed rate during cutting could be increased by 30%. Note that 16 in FIG. 4 is a wedge-type presser foot for fixing the cassette 15, and 17 is a blade edge position adjustment mechanism using a wedge. Loosen the tightening screw of presser foot 16,
When the amount of press-fitting of the wedge of the adjusting mechanism 17 is adjusted with a screw, the position of the cutting edge in the tool radial direction changes.

The cassette 15 may be used to clamp and unclamp chips in the following manner. In other words, the cutting tip is screwed to the tip of the clamp shaft,
Clamping and unclamping are performed by sliding or tilting the clamp shaft in the axial direction with a clamp rod. Furthermore, when unclamping, the clamp shaft is rotated by a certain angle using a ratchet mechanism, and the unused blade of the tip is automatically indexed.

[0016]

Effects of the Invention: Since the feed of the cutting blade is reversed midway and the other end of the rolling groove is cut from the end toward the center in the same way as the one end, chipping due to the cutting force of the rolls does not occur. Further, since the machining diameter can be adjusted by changing the mounting position of the cutting edge tip, there is no restriction on the machining diameter due to the manufacturing limit of the tip. Moreover, the chip used may be small, which is economically advantageous. Furthermore, the cutting tool of the present invention has the effect of enabling efficient implementation of the above-mentioned method and improving machining accuracy.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the method of the present invention.

FIG. 2 is a front view of a lathe for modification.

FIG. 3 is a view taken along arrow A in FIG. 2;

FIG. 4 is an end view showing an example of the tool used.

[Explanation of symbols]

1 Lathe 2 Main shaft 3. Feeding table 4 Feeding device 5 Roll holder 6, 7, 8 Carbide roll 9 Rolling groove 10 Cutting tools 11 Main body 12 Shank 13 Seat groove 14 Sintered diamond cutting tip 15 Cassette 16 Presser foot 17 Blade edge position adjustment mechanism

Claims (2)

[Claims] Claim 1: Carbide rolling rolls are assembled in the same state as during rolling, rotated in one direction, and the cutting edge of a tool inserted between the rolls is fed along a circle concentric with the center axis between the rolls. In a method for modifying carbide rolls that cuts the groove surface of a circular arc rolling mill provided on the roll, the number of cutting blades is the same as the number of rolls set, and they are arranged at equal pitches in the circumferential direction. First cut the grooved surface of the roll halfway from one end to the other, then reverse the feeding direction of the cutting blade and use the same blade to cut the uncut part of the grooved surface of the adjacent roll from the other end to one end. A method for modifying a carbide roll, which is characterized by cutting the carbide roll. 2. A cutting tool used in the method according to claim 1, wherein a number of circular sintered diamond cutting tips equal to the number of set rolls are provided in the circumferential direction on the outer periphery of the tip of the main body having a shank. A cutting tool characterized by being indexed at equal intervals and detachably mounted.