JP2653253B2 - How to cut carbide rolls - 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 cutting a cemented carbide roll (a cemented carbide roll) used for rolling pipes and the like and a cutting tool used for the method.

[0002]

2. Description of the Related Art Carbide rolls used for rolling round pipes or the like are used by combining a plurality of rolls having rolled grooves in an arc so as to form a circular space for molding therebetween. If the circular space at this time has a distorted shape, the roundness of the rolled product deteriorates. Therefore, this kind of roll is made to have the same state as that at the time of rolling after production or repair, and the rolling groove is re-cut.

[0003] With regard to this reshaping, conventionally, a cutting tool having a disc-shaped sintered diamond tip is fed to a roll set in a rolled state and rotated in one direction, thereby transferring the contour of the tip to the roll. There was a method (disk bite method), but this method was limited to 50 mm at the maximum due to the manufacturing limit of sintered diamond chips.
It can be processed only up to the diameter and the tool cost is high because large sintered diamond is used.

[0004] Therefore, as a countermeasure, the same number of cutting blades as one set of rolls are arranged at a constant pitch in the circumferential direction, and the cutting blades are fed in one direction along a circle concentric with the center axis between the rolls, thereby forming the rolling grooves. Was considered from one end to the other end.
According to this method, a small cutting edge tip is required. Further, since the distance from the center between the rolls to the cutting edge of the insert can be set freely, there is no limitation on the processing diameter due to the size of the insert. However, this method has the following problems that hinder its practical use.

[0005]

The method of feeding the cutting blade and shaving the groove surface from one end is not problematic because the roll thickness is sufficiently secured in the feed direction at one end side. Processing on the other end side where the roll thickness is small is not good.

[0006] That is, if the cutting allowance is large, the cutting resistance also increases. In addition, a feed component acts in the pulling direction on the other end side where the cutting blade passes through. However, cemented carbide has lower toughness than steel or the like, and is strong in compressive force but weak in tensile force. For this reason, if the cutting allowance is large, the other end side cannot withstand the cutting force and the roll is chipped.

[0007]

According to the present invention, in order to eliminate the problem of chipping, the number of cutting blades is set equal to the number of rolls set and arranged at equal pitches in the circumferential direction. First, cut the groove surface part way from one end to the other end, then reverse the feed direction of the cutting blade and cut the uncut part of the groove surface of the adjacent roll with the same blade from the other end to one end. I do.

[0008]

The present invention will be described in further detail with reference to the accompanying drawings. In FIG. 1, a roll holder 5 is provided on a spindle 2 of a lathe 1.
On the other hand, a tool feeder 4 is provided on the feed table 3, and a cutting tool 10 is mounted on a main shaft of the device.

The tool 10 has a cylindrical body 1 shown in FIG.
1 has a shank 12 (FIG. 2) at the rear. In the example shown in the drawing, the seat groove 13 is formed on the outer periphery of the tip of the main body 11 at an index angle of 120 degrees.
In each of the seat grooves, a cassette 15 having a circular sintered diamond cutting blade tip 14 mounted thereon so as to be clamped and unclamped is mounted. FIG. 3 shows how the super hard rolls 6, 7, 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, a roll cutting allowance is set. At this time, the roll is already driven and rotating. The tool 10 is fed so that the chip 14 is located between the rolls, that is, at the position (a) in FIG. 1 (the other two chips are omitted in this figure). Then, the tool 10 is rotated so that each chip 14
Is cut into rolls 6, 7, 8 and the tip 14
Feeding is performed until the position of (b) is reached, and the groove surface of the rolling groove 9 is cut.

Next, when cutting is advanced to the portion (b), the feed is stopped, the tool is reversed, and the tip 14 is returned to the cutting start point.
Further, after returning to the portion (a), the tip in which the roll 6 is processed by continuing the rotation in the returning direction is cut into the roll 7 this time, and the uncut portion of the rolling groove of the roll 7 is reversely fed from the other end side. Cutting. Although not shown in the figure, the other rolls are processed in the same manner from the adjacent rolls from one end and the other end.
When the chip shown in (a) reaches the part (c), the remodeling of all rolls is completed.

The feed 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. However, the rotation angle of 60 degrees is not absolute. If the processing is completed at a position rotated by about 10 degrees from the end of the rolling groove, chipping of the roll does not occur. There is only a difference in whether the processing amount in the first feed increases or the processing amount in the return rotation increases, and there is no difference in the processing time. The experimental results are described below.

WC-1 A set of three carbide rolls made of 1.5wt% Co cemented carbide is set on a lathe for reshaping and has a diameter of
Figure 4 with 14mm circular sintered diamond cutting edge tip
The rolling groove was modified with the tool. The processing conditions at this time were a roll peripheral speed of 6 m / min, a feed of 0.2 mm / rev (feed per rotation of the roll), a cutting depth of 0.6 mm, and a water-soluble cutting oil was used.

When the machining was continuously performed in the same direction, chipping occurred on the cut-out side of the roll. However, when the method shown in FIG. No cutting occurred, and the feed during cutting could be accelerated by 30%. 4 is a wedge-type presser foot for fixing the cassette 15, and 17 is a blade edge position adjusting mechanism using a wedge. Loosen the screw of the presser foot 16 and adjust the adjusting mechanism 17
Adjusting the press-fit amount of the wedge with a screw changes the position of the cutting edge in the tool radial direction.

The cassette 15 may perform clamping and unclamping of chips as follows. That is, the cutting blade tip is screwed to the tip of the clamp shaft, and the clamp shaft is slid or tilted in the axial direction by the clamp rod to perform clamping and unclamping. Also,
At the time of unclamping, the ratchet mechanism is used to rotate the clamp shaft by a fixed angle to automatically index unused blades of the chip.

[0016]

According to the present invention, since the feed of the cutting blade is reversed in the middle and the other end of the rolling groove is cut from the end to the center similarly to the one end, chipping due to the cutting force of the roll does not occur. Further, since the processing diameter can be adjusted by changing the mounting position of the cutting edge chip, the processing diameter is not limited by the manufacturing limit of the chip.
In addition, the chip used may be small, which is economically advantageous. Further, the cutting tool according to the present invention has an effect that the above-described method can be efficiently performed and machining accuracy is also improved.

[Brief description of the drawings]

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

FIG. 2 is a front view of a turning lathe.

FIG. 3 is a view taken in the direction of arrow A in FIG. 2;

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

[Description of Signs] 1 Lathe 2 Spindle 3 Feeding Table 4 Feeding Device 5 Roll Holder 6, 7, 8 Carbide Roll 9 Rolling Groove 10 Cutting Tool 11 Main Body 12 Shank 13 Seat Groove 14 Sintered Diamond Cutting Blade Tip 15 Cassette 16 Presser foot 17 Blade position adjustment mechanism

Claims (2)

(57) [Claims] 1. A cemented carbide roll for rolling is assembled in the same state as in rolling and rotated in one direction, and a cutting edge of a tool inserted between the rolls is fed along a circle concentric with a center axis between the rolls. In the method of cutting a carbide roll for cutting the groove surface of an arc rolling mill provided on a roll, cutting blades are arranged at the same number as the number of rolls set and circumferentially at equal pitches, First, cut the groove face of the roll halfway from one end to the other end, then reverse the feed direction of the cutting blade, and turn the uncut part of the groove face of the adjacent roll with the same blade from the other end to one end. Cutting method for carbide rolls, characterized by cutting by cutting. 2. The cutting tool used in the method according to claim 1, wherein the same number of circular sintered diamond cutting blade tips as the number of rolls set are provided on the outer periphery of the tip end of the body having the shank in the circumferential direction. A cutting tool characterized by being indexed at equal intervals and removably mounted.