JPS625700B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a flanged wound bush bearing and a mold used in the manufacturing method.

Conventionally, various types of wound bush bearings are known, which are formed by winding thin metal plates into a cylindrical shape.However, a flange-type wound bush bearing that is integral with the cylindrical part and has a uniform flange with no missing parts is known. Little known. When an attempt is made to bend the end of the cylindrical part outward to form a flange there, the thin plate abutting part (joint part) J opens and forms a fan-shaped notch D, as shown in FIG.
This is because a tsuba with a uniform tsuba surface without any missing portions cannot be formed.

Generally, the role of the flange in a flange bearing is to cope with thrust loads, but the flange can also have other functions such as preventing slippage and rotation. For thin-walled cylindrical bearings (wound bush bearings are generally thin-walled), it is difficult to secure them with split pins or dowel pins after fitting them into the housing, but for bearings with a flange, this flange is In addition to being useful for directly preventing slippage and rotation, this part also has the advantage of being able to be fixed using the pins mentioned above.

When the bearing is subjected to a thrust load, the notch present there generally does not pose a significant problem as a pressure receiving surface, so there are examples of wound bush bearings in which this notch is used as is.

However, such a rolled bush having a brim with a chipped part has a chipped part that has no reason for existence, and therefore its commercial value is reduced. When a thrust load accompanied by an impact is applied, the mating material is likely to be damaged. When a flange with such a notch is formed, radial deformation is concentrated in this part, so even if it is used with the notch still in place, it may require re-pressing or the flange may be damaged. The outer circumferential surface of the product may require trimming using a cutting tool. There are problems such as.

The present invention has been made to solve such problems.

In other words, (a) a uniform tapered part that tapers toward the end (thin wall) is provided on the outer or inner peripheral surface of the end of the winding bush; (b) the outer peripheral surface of the cylinder excluding the tapered part is (c) Pressing the tapered wound bushing in the axial direction of the bushing to bend the tapered portion outward; (d) the bending step. In this method, a pressing force is generated toward the center of the cylinder on the flange that is being formed by restraining the end surface of the outer circumferential surface of the bent portion with a circumferential surface having a dimension smaller than the bending width in the radial direction. A method for manufacturing a wound bush bearing with a flange that has no defects on the flange surface, which consists of the steps (a), (b), (c), and (d) above, and for use in the manufacturing method. The purpose is to provide molds that can

The wound bushing used in the present invention may be one made by simply rolling a thin plate of bearing alloy, or one with a two-layer structure in which a cast layer, sintered layer, or plastic layer of bearing alloy is provided on a cold-rolled steel plate. Examples include a three-layer structure in which a porous sintered metal layer is provided on the surface of a thin steel plate, and this is filled and coated with a low-friction plastic layer.

The taper chamfering performed prior to the formation of the flange is performed on the outer circumference side of the bush if the above-mentioned coating layer is also present on the flange surface, and on the inner circumference side when the coating layer is not required on the flange surface. It can be applied to As shown in Figs. 2 and 3, the length L of this tapered chamfer is W - t, that is, the width of the back surface of the flange, where W is the width of the flange and t is the wall thickness of the cylindrical part. It is necessary to keep it larger than w.

According to experiments by the inventors, L=α・w, α=
It was found that good results could be obtained by setting the ratio to 1.1 to 2.2.

The value of α varies depending on the plastic flowability of the material used, the presence or absence of a coating layer on the flange surface, its structure, and the thickness of the flange to be formed. For example, if the flange surface has a resin coating layer, In this case, it is preferable to set the value of α to be approximately larger than the median value in the above range. In addition, in those without a resin coating layer on the brim surface, the value of α is preferably set to the lower limit side of the above range.

Next, the chamfer depth S of the taper depends on the same factors as when selecting the length L and the size of the wall thickness t of the cylindrical part, but the taper length L
It is preferable to adopt 1/3 of this as the standard value.
(However, if the width of the flange is large, the dimension should be smaller than 1/3 of L.) Furthermore, the unique feature of the rolled bushing with a flange of the present invention is that the thickness f of the flange is the same as the wall thickness t of the cylindrical part. This means that it can be formed to a certain thickness, or it can be formed to be slightly thicker or thinner. This thickness f is determined by the mutual relationship between L, S, and the desired flange width W (or back width W of the flange).

The formation of this tapered chamfer is important from the perspective of facilitating the formation of the flange using a mold, and is especially essential for manufacturing rolled bushings that have a coating layer on the surface that forms the sliding surface. However, if there is no taper, the coating layer will be seriously damaged and a satisfactory rolled bushing with a flange cannot be obtained.

FIG. 4 is a longitudinal cross-sectional view for explaining the main parts of a mold used for manufacturing the flanged wound bush bearing of the present invention.

In the figure, 1 is a lower mold, which is fixed, for example, on the base of a press. Reference numeral 2 designates a sliding surface on which a clamping die, which will be described later, comes into sliding contact, and reference numeral 3 designates a hole into which the tip of a punch, which will also be described later, is inserted and guided.

Reference numeral 4 denotes a clamping mold divided in the vertical direction, and 5 is a lower surface thereof, which slides into sliding contact with the sliding surface 2 of the lower mold 1. 6 is the upper surface of the clamping die 4;
It comes into contact with the upper bottom surface of the collar tightening die, which will be described later. Reference numeral 7 indicates a hole provided through the upper and lower surfaces 5 and 6, and 8 indicates a tapered surface that widens toward the bottom of the mold. The hole 7 has a hole diameter corresponding to the outer diameter of the winding bushing when the divided clamping mold is clamped. It is necessary that the arcuate length of this hole is divided equally, and usually it is divided into two parts, and each semicircle is combined to form a circular hole.

Reference numeral 9 denotes a flange clamping type, which has an opening 10 facing downward and has a substantially U-shaped vertical cross-sectional structure.

11 is a hole that fits into the large diameter part of the punch, which will be described later;
It is open to the upper base surface 12, and 13 is opened to the upper base surface 12.
A tapered surface that widens toward the opening 10 from the periphery slides into contact with the tapered surface 8 of the clamping die 4 described above.

A cam slide mechanism is constituted by the engagement and sliding contact between the tapered surfaces 13 and 8 of the flange clamping mold 9 and the clamping mold 4, and the cylindrical portion of the winding bush is moved by the cam sliding action of the clamping mold. Pressed towards the center of the cylinder.

14 is a punch, 15 is a small diameter portion thereof, 16 is a shoulder portion, and 17 is a large diameter portion continuous to the shoulder portion 16.

The small diameter portion 15 is tightly fitted into the inner hole of the cylindrical portion of the winding bushing, and its tip is inserted and guided into the hole 3 of the lower mold 1.

The large diameter portion 17 is tightly fitted into the hole 11 of the flange clamping die 9, leaving a gap in which the flange of the wound bushing is formed.

The shoulder portion 16 faces the upper surface 6 of the clamping die 4, pinches the collar portion of the winding bushing therebetween, and presses it in the axial direction. At this time, the hole 11 having a hole diameter closely approximated to the diameter of the punch large diameter portion 17 has a hole diameter smaller than the flange diameter formed by bending the bush end portion in a free state without restraint in the radial direction. Since the flange is formed with a cylindrical shape, the flange that is being formed is pressed toward the center of the cylinder, causing plastic flow in the flange, thereby making it possible to obtain a flange-wrapped bushing having a flange without any defects. It is particularly preferable that the longitudinal cross-sectional shape of this shoulder portion 16 has a smooth circular arc surface.

FIG. 5 shows a perspective view of the flanged wound bush bearing of the present invention, which is thus obtained and has no missing parts.

If the flange is formed without generating a pressing force acting toward the center of the cylinder on the flange that is being formed, the flange will have a fan-shaped notch D on the flange surface, as already explained in FIG. I become confused.

The opening angle of this notch D reaches approximately 70 degrees.

FIG. 6 is a longitudinal cross-sectional view showing an embodiment of the mold of the present invention, and the main constituent members are shown with the same numbers as in FIG. 4.

18, 18 are rods fixed to respective divided pieces of a clamping mold that is vertically divided into two parts, 19,
19 is a pullback spring.

The retraction springs 19, 19 are attached to the respective rods 1
Block 2 fixed to the head and machine base of 8 and 18
5, 25, and when the tapered surfaces of the collar part clamping die 9 and the clamping die 4 disengage, the clamping die 4
Give the rod the power to slide and open the mold.

Reference numerals 20 and 21 refer to pusher pads that allow the flange clamping die 9 and the punch 14 to move up and down and apply pressing force to them; 23 indicates an elastic body installed between the pusher pad 20 and the flange clamping die 9; and 24 indicates an elastic body. It is an elastic body installed between a member such as a ram (not shown) located above and the punch head, and has a cushioning function to perform initial mold clamping.

Reference numerals 22, 22 are bolts whose one end is screwed into the collar part clamping die, and whose other end on the head side is held by the pusher pad 20 with play 26 in the operating direction.

27 is the punch head and pusher pad 20,2
With almost the same play as the play 26 given between 1 and 2, together with the elastic bodies 23 and 24, mold clamping safety is ensured.
Contributes to improving smoothness and reliability.

As explained above, the present invention uses a winding bushing having a uniform taper on the outer circumferential surface or inner circumferential surface of the end, which tapers uniformly toward the end. It is possible to obtain a rolled bush bearing with a flange that has no missing parts.

In addition, in the explanatory drawings and the example drawings, the formation of the flange that is perpendicular to the cylindrical portion of the winding bushing has been explained, but if necessary, it is also possible to form the flange with an angle other than the right angle. The planar shape of the tsuba may also be other than circular.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional wound bush bearing with a flange, Fig. 2 is a vertical cross-sectional view of a tapered wound bush used for forming the flange, and Fig. 3 is a wound bush bearing with a flange of the present invention. FIG. 4 is a vertical cross-sectional view showing the main parts of a mold used for manufacturing the flanged wrap bush bearing of the present invention, and FIG. 5 is a perspective view of the flanged wrap bush bearing of the present invention. FIG. 6 is a longitudinal sectional view showing an embodiment of the mold of the present invention. 1: Lower mold, 4: Clamping mold, 8: Tapered surface, 9:
Flange tightening mold, 13: Tapered surface, 14: Punch,
11: hole, 16: shoulder.

Claims (1)

[Scope of Claims] 1. (a) A uniform tapered portion that tapers toward the end (thin wall) is provided on the outer circumferential surface or inner circumferential surface of the end of the winding bushing; (b) The tapered portion (c) Pressing the tapered wound bushing in the axial direction of the bushing to force the tapered part outward. (d) In the bending step, the outer circumferential end surface of the bent portion is restrained by a circumferential surface having a dimension smaller than the bending width in the radial direction, so that a cylindrical shape is formed in the collar portion that is being formed. There is no defect in the collar surface, which is characterized by generating a pressing force toward the center and causing plastic flow there, and consisting of the steps (a), (b), (c), and (d) above. A method of manufacturing a rolled bush bearing with a flange. 2. (a) A sliding surface on which the clamping mold slides, a lower mold provided on the sliding surface and having a hole into which the tip of the punch is inserted and guided, (b) an outer circumferential surface having a taper, and the lower mold mentioned above. A clamping mold that has a lower surface that slides in contact with the mold, an upper surface that contacts the flange pressing mold, and a hole that penetrates the upper and lower surfaces, and is divided vertically including the hole;
(c) A top bottom surface that comes into contact with the top surface of the clamping mold and has a hole into which a punch fits, and a top bottom surface that spreads uniformly from the periphery of the top bottom surface and slides into contact with the tapered outer circumferential surface of the clamping mold. a flange clamping mold with a tapered inner surface; (d) a small diameter portion that is tightly fitted into the inner diameter of the winding bushing attached to the mold and whose tip is inserted into the hole of the lower mold; and the flange. It consists of a punch having a large diameter part that fits into a hole in a clamping die, and a shoulder part that extends from the small diameter part to the large diameter part, and has an outer circumferential surface or an inner circumferential surface of the end tapered toward the end. A winding bushing with a uniform taper is placed on the lower mold, and the tapered part of the winding bushing is removed by the cam slide action caused by the engagement of the inner and outer tapered surfaces of the clamping mold and the flange clamping mold. The outer peripheral surface of the circumference is pressed toward the center of the cylinder by a clamp die, and as the punch descends, the tapered end of the rolled bush is bent at the shoulder, pressed in the axial direction, and bent. The structure is such that a pressing force is applied toward the center of the cylinder by the hole circumferential surface of the flange clamping die to the flange that is being formed at the same time, causing plastic flow there and forming a flange without any defects. A mold used in the manufacturing method of a wound bush bearing with a flange.