GB2218749A

GB2218749A - Half bushes

Info

Publication number: GB2218749A
Application number: GB8907919A
Authority: GB
Inventors: Sanae Mori; Takayosi Sasaki; Noriyoshi Ito
Original assignee: Daido Metal Co Ltd
Current assignee: Daido Metal Co Ltd
Priority date: 1988-04-07
Filing date: 1989-04-07
Publication date: 1989-11-22
Anticipated expiration: 2009-04-07
Also published as: JPH01261515A; KR930006499B1; GB8907919D0; DE3911441C2; KR890016302A; GB2218749B; JPH0758096B2; DE3911441A1

Description

rl r) 't -i ' '.Q 7 4 9 1 Half Bushes 1.

The present invention relates to a method of manufacturing half bushes, and to half bushes so manufactured.

A method of manufacturing half bushes is known from Japanese Patent Publication No. 56-41342. In the known method, an elongate strip to be made into a half bush is fed into a press in a stepwise manner longitudinally of the strip. The press is actuated each time the strip makes a step forward, to successively cut the strip widthwise into a plurality of blanks different froik each other. These blanks are then pressed to manufacture split outer bearing plates.

The known method has the following problems:

1) A strip-like plate to be fed into the press is required to be cut into a length substantially equal to a peripheral length of a half bush. Alternatively, the plate is required to be cut within the press. In either case the cutting tends to produce chips at the end of the plate, sometimes making it unsuitable for use. The consequent abatement means that the yield tends to be low.

2) Contiguous blanks chamfered by embossing are cut along V-shaped grooves, each pair of which are opposed to each other. Accordingly, each cut surface is brought to a configuration in which it is accompanied by a broken surface. This is aesthetically unpleasing.

Further, when a half bush formed from the blank is assembled into an engine, there is a fear that fine or minute particles may fall from the cut surface.

3) The process by which each cut blank is forced into 2 a half-cylindrical coining die by a bending punch relies only upon the friction of a small part of the surfac-e of the cut blank which is brought into contact with the half-cylindrical coining die. Therefore, there is a fear that the blank may shift due to imbalance of friction.

4) In the aforesaid process, the blank tends to be lifted from the top of the bending punch during the lu bending process so that the blank is formed with a radius smaller than that of the bending punch. As the forming proceeds, the blank is again brought to a configuration identical with that of the bending punch. Thus, undue force is applied to the bearing alloy.

Is It is an object of the invention to provide a method of manufacturing a half bush, which is capable at least of alleviating the above-discussed problems of the prior. art.

According to the present invention there is provided a method of manufacturing a half bush 2U comprising processing an-elongate strip by continuous machining thereof to form a processed strip having a width corresponding generally to that of a bush to be manufactured, cutting a blank from the processed strip, 'bending the blank into a generally half-circular configuration while restraining movement in a radial direction, and compressing the blank to reduce its peripheral length while retaining movement in a widthwise direction.

There is also provided a method of manufacturing a half-split bearing from a strip-like plate, comprising the steps of:

a) carrying out processing of opposite side faces of a wide strip-like plate and chamfering thereof, to 14 C 3 j continuously machine the strip-like plate into a strip like plate having a width corresponding to a width of an objective half-split bearing; b) cutting the machined strip-like plate into a length corresponding to that of the objective half split bearing to form a blank, and bending opposite ends of the blank while restraining the same in a wall thicknesswise direction; lu C) further bending the bent blank into a half circular configuration substantially corresponding to a final configuration of the half-split bearing while restraining the blank in the wall-thicknesswise direction; d) reducing a length of the half-circular blank while restraining inner and outer peripheral surfaces of the half-circular blank and, further, forming the half circular blank while restraining the same widthwise; and e) subjecting a formed article to oil-hole processing and notch processing.

a) carrying out at least one of processing of _ opposite side faces of a wide strip-like plateand chamfering thereof, to continuously machine the striplike plate into a strip-like plate having a width corresponding to a width of an objective half-split bearing; b) cutting the machined strip-like plate into a length corresponding to that of the objective halfsplit bearing to form a blank, and bending opposite ends of the blank while restraining the same in a wall 4 thicknesswise direction; c) further bending the bent blank into a half circular configuration substantially corresponding to a final configuration of the half-split bearing, while restraining the blank in the wall-thicknesswise direction; d) reducing a length of the half-circular blank while restraining inner and outer peripheral surfaces of-the half-circular blank and, further, forming the half circular blank while restraining the same widthwise; and e) subjecting a formed article to at least one of oil-hole processing, notch processing and oil-groove processing.

Further, there is provided a method of manufacturing-a half-split bearing from a strip-like plate, comprising the steps of:

a) subjecting a wide strip-like plate to at least one of width processing, chamfering, oil-groove processing, oil-hole processing, wall-thickness processing, embossing, and mark- applying processing, to continuously machine the strip-like plate into a striplike plate having. a width corresponding to a width of an objective half-split bearing; b) cutting the machined strip-like plate into a length corresponding to that of the objective half split bearing to form a blank, and bending opposite ends of the blank while restraining the same in a wall thicknesswise direction; c) further bending the bent blank into a half circular configuration substantially corresponding to a final configuration of the half-split bearing, while restraining the blank in the wall-thicknesswise ic 11 W 11 direction; and d) reducing a length of the half-circular blank while restraining inner and outer peripheral surfaces of the half-circuiar blank and, further, forming the half circular blank while restraining the same widthwise.

The half bush according to the invention has the following advantages:

1) Since no abatement of the peripheral length is - produced at cutting, the yield is high.

fu 2) since the processing of the side faces and the chamfering thereof are carried out my machining or cutting, the appearance is good. Further, since the half bush has no broken surface, fine or minute particles do not fall fom the broken surface when the half-bush is assembled into an engine so that there is provided a clean interior of the engine. Moreover, since the machining or cutting is effected continuously, the service like of the tools can be prolonged.

3) At the stage of the blank, the opposite peripheral ends of the blank are bent beforehand, whereby the blank can be formed into a half-circular shape without difficulty. In this connection, the roundness and the straightness in the vicinity of the opposite ends of the half-circle can be improved.

4) In bending into a half-circular shape, the blank is restrained in the wall-thicknesswise direction, whereby the blank is always in contact with the bending punch. Thus, no undue stress occurs in the bearing alloy.

The invention may be carried into practice in a number of ways and one specific method will now be described, by way of example with reference to the 6 drawings, in which:

Fig. 1 shows the steps of a method of manufacturing a half bush; and 9 Fig. 2 is a perspective view of a forming device.

Referring to Fig. 1, there is shown an exemplary method of manufacturing a half bush according to the invention. In a first step of the method, a strip-like plate 10 having a certain width is machined to continuously by a cutting tool 12. Specifically, both side faces of the plate 10 are continuously worked by the cutting tool 12. Inner and outer surfaces of the plate 10 are also continuously chamfered by the cutting tool 12, correspondingly to chamfering of inner and i outer peripheral surfaces of a half bush. Thus, the plate 10 is formed into a completed strip-like plate 14 which has a reduced width required for the half bush. At this time, it is preferable that the amount of widthwise cutting is of the order of 0.05 mm to 0.1 mm on one side.

In a second step, a mark 16 such as a trademark, a part number and so on is applied to the surface of the plate 14, on the side which will form the outer peripheral surface of the half bush.

In a third step, the plate 14 is cut into a length corresponding substantially to the peripheral length of the half bush to form a blank 18.

In a fourth step, both peripheral ends of the cut blank 18 are bent into a half-circular shape with high accuracy, to form a semi-processed article 20 in the jo form of a half-circle. The blank 18 is restrained in the wall- thickness direction, during the cutting and the bending.

In other words, during this step the blank is 4 A 1 7 rigidly held from above and below its central portion, while the ends are bent. This produces an article having an accurate roundness but with a slightly larger peripheral length than that of an exact half-circle.

In a fifth step, the semi-processed article 20 is formed into a semiproduct 26 in the form of a final half-circular configuration substantially corresponding to a final configuration of the half bush, by means of a coining die 22 and a forming punch 24 (figure 2). At this time, the semi-product 26 is again restrained in the wall-thickness direction in a manner similar to that of the fourth step. In this fifth step, the halfcircular semi-product 26 is pressed down while being restrained by the highly accurate coining die and forming punch 22 and 24. The semi- product 26 is reduced in peripheral length by blocks 28 shown in Fig. 2, thereby obtaining a highly accurate half bush. At the pressed-down position, there is provided a side plate 30 (see Fig. 2) which restrains the semi-product 26 widthwise. By means of the side plate 30, the _ material which is effectively lost from the peripheral length by the blocks 28 is made use of in correcting the width of the half bush to its required value. The internal pressure of the material is raised so that a highly accurate half-split bearing can be manufactured; during this process the article 20 is not subjected to any compression which will result in a plastic deformation in the thicknesswise direction, but there is plastic deformation in the circumferential direction.

Finally, in a sixth step an oil hole 34 and a notch 36 are formed.

In connection with the above-described third and Z 8 fourth steps, the cutting and the bending of one peripheral end of the blank may comprise a step distinct from the cutting and bending of the other end. Further or in addition, the oil hole 34 and the notch 36 may be formed beforehand in the strip-like plate 14. The embossing and the wall-thickness processing may also be carried out beforehandon the strip- like plate. Furthermore, if an oil groove or the like is required depending upon the use of the bearing, this may be formed either in the strip-like plate 14 or after the bending.

X 1 s w A X cl - JU 9

Claims

1 () 1. A method of manufacturing a half bush comprising processing an elongate strip by continuous machining thereof to form a processed strip having a width corresponding generally to that of a bush to be manufactured, cutting a blank from the processed strip, bending the blank into a generally half-circular configuration while restraining movement in a radial direction, and compressing the blank to reduce its peripheral length whiie -restraining movement in a widthwise direction.

2. A method as claimed in Claim 1 in which the processing of the elongate strip includes chamfering the edges thereof.

3. A method as claimed in Claim 1 or Claim 2 in which the processing of the elongate strip includes 20 width processing.

4. A method as claimed in any one of Claims 1 to 3 in which the processing of the elongate strip includes thickness processing.

5. A method as claimed in any one of Claims 1 to 4 in which the processing of the elongate strip includes at least one of oil-groove processing, embossing and mark-applying.

6. A method as claimed in any one of Claims 1 to 5 in which the bent and compressed blank is subjected to oil-hole and notch processing.

7. A method of manufacturing a half bush substantially as specifically described, with reference to figures 1 and 2.

8. A half bush when manufactured by a method as claimed in any one of the preceding claims.

1 U Is 1 1 Publi shed 1989 at The Patent Office. State House, 66 71 Ingh Holborn. London WC1R 4TP FV-"ther copies maybe obtainedfrom The Patent Office.