JPH03121713A - Machining method for cylindrical work - Google Patents

Abstract

PURPOSE:To attain complete removal of welding bead with one run of machining process by pressurizing the small wall thickness part of a coarsely machined welded part from one side, and making follow-up machining to the coarse machining tool with a finishing tool, which is located on the opposite side to the pressurization direction. CONSTITUTION:When the two sides of the welded part Wz of a work W are pressurized and restrained by clampers 51, 52 and tools 53, 1, 2 are fed for machining in the (f) direction, first coarse machining tools 53, 53 and then intermediate machining tools 1, 1 will cut off the welding bead Be. Because the central part of the work W is at this time turned in small wall thickness, recess Q1 is curved so as to appear to the rear side, which produces an unmachined part Fe. Therefore, a pressurizing roller 3 and the finishing tool 2 are sent in following-up to the intermediate machining tool 1, to make finish machining of this unmachined part Fe. Therein the pressurizing roller 3 works to depress the welded part Wz, so that the unmachined part Fe is swollen and cut off by the finishing tool 2 which makes synchronous motion with the pressurizing roller 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for cutting cylindrical workpieces, such as road wheel rims, and more specifically, a method for cutting cylindrical workpieces such as road wheel rims, and more specifically, a method for cutting cylindrical workpieces such as road wheel rims. This invention relates to a method for cutting a welded part of a workpiece.

In the conventional method for manufacturing road wheel rims made of steel plates, as shown in Figure 4, a rectangular steel plate is used as the material P, and the steps are coiling → welding (flash butt or DC butt welding) → trimmer processing → side cut processing. By going through each process, a cylindrical workpiece W, which is the rough shape of a road wheel rim, is extracted, and then sent to the roll forming process (for example, "Automotive Engineering Complete Book Volume 19 Automobile Manufacturing Method", (Showa) 55.4.20), Sankaido, P156).

The above trimmer processing can be done by flash butt welding or D
This is for the purpose of cutting and removing the weld bead of the welded part caused by C-butt welding, and as shown in Fig. 5, both sides of the welded part Wz are pressurized and restrained with a pair of upper and lower clampers 51, 52, and then welding is carried out. A rough cutting tool 53.53 and a finishing tool 54.5 are arranged oppositely above and below part W2.
4, cutting is performed by applying a feed f in the longitudinal direction of the welded portion Wz.

In addition, in the side cut processing, even after the above-mentioned trimmer processing is performed, there is still a weld bead burr F on both end faces of the weld Wz.
This is done for the purpose of cutting and removing this burr F.

Incidentally, in order to reduce the weight of the road wheel rim while maintaining its strength, a rolled steel plate with an irregular cross section is sometimes used in place of the above-mentioned general steel plate. As shown in Figs. 6 and 7, this irregular cross-section steel plate Pa has a central portion in the width direction that is locally thinned from one side, and when applied to a road wheel rim R, the edge portion e This contributes to improving rim rigidity by ensuring a relatively large plate thickness, while at the same time reducing the plate thickness near the center drop CD by approximately 20%.
It has been confirmed that the overall weight can be reduced by 5 to 10%.

Here, the reference plate thickness T of the irregular cross-section steel plate Pa shown in FIG. 6 is 2
．． 0 to 5, Oxi, thick part E of 1.1 to 1.3T at both ends in the plate thickness direction (i2 = 20 to 5Qxx
), and the wall thickness is gradually reduced toward the center, and the minimum wall thickness Pc, which is the smallest wall thickness among the thin wall sections Q, is 0.7.
~o, s'ro.

Problems to be Solved by the Invention Using the above-mentioned irregular cross-section steel plate Pa, FIG. 8(A),
As shown in (B), when welding is performed after coiling with the thin wall portion Q facing the outer peripheral surface, both ends of the welded portion Wz are deformed in the direction of arrow a due to thermal strain. In addition, Figure 8 (
The shaded areas indicated by the symbol Be in B), (C), and (D) indicate weld bead areas produced by flash butt welding or DC butt welding.

Then, both sides of the welded part Wz are shown in Fig. 5 and Fig. 8 (C).
As shown in FIG.
4.54, the longitudinal center of the weld Wz bulges outward due to the restraining force of the clampers 51 and 52, so both the front and back surfaces of the weld Wz are cut parallel to each other. However, as shown in FIG. 8(E), an uncut portion Fe is generated on the inner peripheral surface side. As a result, when the restraining force by Cranno F-51, 52 is released after trimmer processing is completed, the uncut portion Fe of the weld bead Be protrudes inward due to the restoring force of the weld Wz, as shown in Fig. 8 (F). It turns out.

If the workpiece W with such uncut portions Fe is supplied to the next step of roll forming, the road wheel rim cannot be formed into a perfect circle, resulting in poor runout accuracy.

Therefore, before roll forming, it is necessary to perform trimmer processing again for the purpose of removing the uncut portion Fe, resulting in an increase in the number of man-hours.

The present invention was made in view of the above problems.
The present invention aims to provide a method that allows a weld bead portion of a welded portion to be reliably cut and removed in a single operation even though the workpiece is a cylindrical workpiece made of a steel plate with an irregular cross section.

Means for Solving the Problems The present invention relates to a cylindrical workpiece formed by coiling a rectangular irregular cross-section steel plate with a thinned central part in the width direction, and welding the two end faces together.
This is a method of cutting the welded part, in which both sides of the welded part are pressurized and restrained by a pair of clampers on the front and back, and a rough cutting tool is placed facing each other on both sides of the welded part. a step of rough-cutting the welded part by applying feed in the longitudinal direction, and locally applying pressure from one side to a portion corresponding to the thin-walled part of the welded part rough-cut under pressure restraint by the clamper; The process includes a step of performing finishing cutting using a finishing cutting tool that is placed on the opposite side of the pressurizing direction across the welding part and follows the rough cutting cutting tool.

Here, it is more preferable to cut with the intermediate cutting tool immediately after cutting with the rough cutting tool, and to perform finishing cutting with the finishing tool that follows the intermediate cutting tool.

Effect: According to the above method, by applying pressure to the portion corresponding to the thin wall portion from one side after rough cutting, the uncut portion of the weld bead portion protrudes to the side opposite to the pressing direction. Then, by cutting this uncut portion with a finishing tool, all the weld bead portions are removed in one operation.

Embodiment FIG. 1 is a diagram showing an embodiment of the present invention, and shows an example in which the present invention is applied to a method for manufacturing a road wheel rim R as in the conventional example, and the same parts as in the conventional example are given the same reference numerals. It is.

As shown in FIG. 1, a pair of medium cutting tools 1, 1 are arranged after the rough cutting tools 53.53 in place of the conventional finishing tools 1-54.
A finishing tool 2 and a pressure roller 3 as a pressure means are arranged facing each other at a later stage in the cutting direction. The finishing tool 2 and the pressure roller 3 are fixedly supported together with the roughing tool 53, 53 and the medium tool 1, 1 on a common slide (not shown), and the pressure roller 3 is connected to a spring or a hydraulic cylinder via a holder 4. A downward pressing force is applied.

As shown in Fig. 2 (A), the processing procedure is as follows:
After pressing and restraining both sides of the welding part Wz with the clampers 51.51 and 52.52 shown in Fig. 1, each bite 53.5
3 and 1.2 are given cutting feed in the direction of arrow f. When the cutting feed is applied, as shown in FIG. 2(A), the preceding rough cutting tool 53.53 cuts the weld bead portion Be on both the front and back sides of the weld zone Wz, and then the rough cutting tool 53.53
The medium cutting tool 1, 1 that follows the rough cutting tool 53
．． In step 53, the weld bead portion Be that could not be completely cut is removed.

At this time, the material Pa itself (Fig. 2 (A
), excluding the weld bead Be, is a concave portion Q due to thinning due to the pressurizing restraining force of the clamper 51, 52.
1 is curved so that it appears on the back side (inner peripheral side of the workpiece W), and therefore, as shown in FIG. are parallel to each other, but an uncut portion Fe of the weld bead Be is generated at the center of the back surface of the weld Wz.

Furthermore, as shown in Fig. 2 (B),
This medium cutting tool 1, 1 was cut before the cutting was completed.
The pressure roller 3 and the finishing tool 2 which follow the welding part Wz are sandwiched between the top and bottom of the welding part Wz, and the finishing tool 2 cuts off the uncut part Fe left by the intermediate cutting tools 1 and 1.

At this time, the pressure roller 3 presses the welded portion Wz by its pressure.
The pressure roller acts to push down the central part of the workpiece W according to the change in thickness, and brings the lower surface of the workpiece W, which is pressurized and restrained by the clampers 51 and 52, into close contact with the lower clamper 51. 3 rolls, the uncut portion Fe left on the back surface of the welding portion Wz bulges out, and the finishing tool 2, which moves in synchronization with the pressure roller 3, scrapes off this uncut portion Fe.

As a result, all the weld bead parts Be on both the front and back sides of the welding part Wz are cut and removed by - times of cutting, and the clamper 51.
By releasing the pressure restraining force 52, the welded portion Wz is restored to its original irregular cross-sectional shape as shown in FIG. 2(C).

Incidentally, the burrs F left on both end faces of the welded portion Wz are cut and removed in the side cutting process in the post-process as explained in FIG. 4.

FIG. 3 shows another embodiment of the present invention. In this embodiment, in place of the pressure roller 3 shown in FIG. 1, a pressure means using a hydraulic cylinder 5 as a driving source is installed in the upper clamper 12. A movable clamper 6 is provided which can be moved up and down.

That is, as shown in FIGS. 3(A) and 3(B), the movable clamper 6 is not operated until the middle cutting pie) 1.1 finishes cutting the part corresponding to the thin wall part Q of the welded part Wz. The movable clamper 6 is made to function as a part of the clamper 12, and the movable clamper 6 is moved downward immediately before the finishing tool 2 starts cutting the portion corresponding to the thin wall portion Q.
As shown in FIG. 3(C), the thin portion Q is pushed down and elastically deformed. As a result, as shown in FIG. 3(D), the uncut portion Fe bulges downward and is removed by the finishing tool 2 as in the previous embodiment.

Here, the present invention can also be applied to cutting workpieces made of general uniform cross-section steel plates rather than irregular cross-section steel plates, and in that case, variations in plate thickness can be absorbed by applying local pressure. This has the advantage of improving the cutting and removal efficiency of the weld bead.

Effects of the Invention As described above, according to the present invention, the part corresponding to the thin wall part of the roughly cut welded part is pressurized from one side, and the welded part is placed on the opposite side to the above pressing direction. By using a finish cutting tool that follows the rough cutting tool, the weld bead can be neatly removed over the entire width of the welded part in - times of cutting, and it is possible to remove the weld bead cleanly over the entire width of the welded part, without using the conventional secondary cutting tool. No machining is required, reducing man-hours.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram of a cutting device to which the method of the present invention is applied, FIGS. 2(A) and (B) are process explanatory diagrams showing a first embodiment of the present invention, and FIG. 3(A). (B), (C), and (D) are process explanatory diagrams showing other embodiments of the present invention, Fig. 4 is a process explanatory diagram showing a conventional road wheel rim manufacturing method, and Fig. 5 is a process explanatory diagram showing a conventional method for manufacturing a road wheel rim. An explanatory diagram of the configuration of the processing device used for processing, FIG. 6 is a cross-sectional view of a steel plate with a modified cross-section, FIG. 7 is a cross-sectional view of a road wheel rim using a steel plate with a modified cross-section, and FIGS. 8 (A), (B), (C),
(D), (E). (F) is a process explanatory diagram of a cutting method using the processing apparatus of FIG. 5. 1... - Medium cutting tool, 2... Finishing tool, 3...
・Pressure roller, 5... Hydraulic cylinder, 6... Movable crank nok-12, 51, 52... Clamper, 53.
・Rough cutting tool, Be...Weld bead, Fe...
・Uncut portion, Pa... irregular cross-section steel plate (material), Q.
...Thin wall part, W...Workpiece, Wz...Welding part. Fig. 1 Fig. 2 (A) Fig. 2 (B) 1 1: 1F wafer cutter 2: Inanakami 1st 0ite 3: Po pressure roller 5152° Granbar 53: Rehite Be: Waste Ceramic bead 9P W: Workpiece Wzo IN Eaves Fig. 2 (C) Fig. 3 (A) Fig. (B) Fig. (C) Fig. Coil link trimmer processing ↓ Fura, sieve + doc + pine ton, t ! Side cut fJO engineering 2 Figure c Figure procedure amendment. Ka style. February 7, 1990 Patent Application No. 259785 of 1999 2゜Name of the invention Cutting process method for cylindrical workpiece 3゜Relationship with the amendment person case

Claims (1)

[Claims] (1) For a cylindrical workpiece made by coiling a rectangular irregular cross-section steel plate with a thinned central part in the plate width direction and welding the two end faces together, this method involves cutting the welded part. Then, both sides of the weld are pressurized and restrained by a pair of clampers on the front and back, and rough cutting is performed by applying feed in the longitudinal direction of the weld to a rough cutting tool placed opposite to each other on both sides of the weld. A step of applying pressure locally from one side to a portion corresponding to the thin-walled portion of the welded portion that has been roughly cut under pressure restraint by the clamper, and applying pressure in the direction of the applied pressure across the welded portion. A method for cutting a cylindrical workpiece, comprising the steps of: finishing cutting with a finishing tool placed on the opposite side and following the rough cutting tool.