JPH08312636A - Suspension component - Google Patents

Abstract

PURPOSE: To apply a suspension component which is not machined, coarse in surface roughness, and in a molding surface state of dimensional dispersion, to serve, by forming the component into a solid body respectively having the whole or some sorts of the bush mounting part, the ball joint part, and the shaft part on the fixed part positions of the arm part. CONSTITUTION: An inner diametral surface of a thick wall part 15 of a bush mounting part is not a straight cylinder but provided with a recessed part 30 in the shaft center direction on the center, and it exhibits an effect of stress relaxation by elastic deformation. By forming the recessed part in the shaft center direction, deforming allowance in the circumferential direction by elastic deformation becomes larger compared with the case of a straight cylinder, and hence a bush can be press-fitted even in the state of casting surface of large surface roughness and dimensional dispersion, and drawing resistance is also large. The recessed part in the shaft center direction can be formed in the full length in the shaft center direction. An inner face of a gripping part 6 is unnecessary to be machined and can be applied even in the casting surface, by injecting outer wrapping material 7 and solidifying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension component used as a suspension system for passenger cars and commercial vehicles, and more particularly to a suspension arm.

[0002]

2. Description of the Related Art The role of a suspension is to soften the impact from the road surface, to improve the riding comfort, to stabilize the posture of the vehicle body while driving, to improve the ground contact of tires, and to drive, brake and steer. It is to improve the ability to transmit power. If a soft suspension is used with an emphasis on riding comfort, the posture of the vehicle body will not be stable and the ground contact of the tire will be impaired. On the other hand, if it is hard, the posture will be stable, but the riding comfort will be poor and the ground contact of the tire may be impaired. It is the role of the suspension to balance these conflicting elements of riding comfort and steerability at the highest possible level, and it gives the ability suitable for the vehicle type. The basis of the suspension is the spring, which absorbs the shock, and the suspension is composed of a framework that transmits the force of the spring to the tires in a manner that suits the purpose. An arm composed of a metal rod or a plate is used for this skeleton. From large A-shaped or V-shaped to simple metal bars,
There is an I-shaped one to maintain strength. In addition to arms, there are various names such as rods and links. The arms are rarely fixed completely, and the movable parts are provided so that the tire can move in the required direction. Therefore, a ball joint portion, a bush mounting portion to which a rubber bush is mounted, and the like are arranged at the connecting portions of the suspension components such as the arms.

A suspension arm typified by an upper arm and a lower arm is connected to a knuckle through a ball joint, and wheels are attached to this knuckle. Conventionally, as shown in FIG. 13B, the arm portion was formed of sheet metal, but it was impossible to integrate the ball joint portion because it was formed of a thin steel plate.
Therefore, a structure is used in which the arm part is made of sheet metal and a separate ball joint is press-fitted, and these are separately welded or bolted to firmly hold the press-fitted separate ball joint. The suspension arm of the structure was also used. FIG. 13C is a view as seen from the arrow BB. Further, FIG. 13D is a view taken along the arrow AA.

In the case of bolt fastening, the patch is welded only to the mounting portion of the thin steel plate arm to increase the thickness and secure the strength of the fastening portion, and then bolt fastening. In this way,
The problem is that the number of parts such as bolts and nuts is large, and the weight is heavy. There are also cases where welding or snap rings are used to prevent disengagement, but the problem in this case is that the reliability of the disengagement force is low and backlash occurs.

Further, the ball joint portion 1 shown in FIG.
Is machined with high precision on the inner surface of the holding portion 6, and is inserted with the ball-shaped shaft body 4 fitted to the resin outer packaging material 7 solidified by injection molding, and the collar 8 is caulked after setting. There is.
9 is a caulking part. Further, 25 is a dust cover. Since the sphere 5 is thus wrapped by the outer wrapping material 7 and is crimped by the crimping portion 9, the shaft body 4 with spheres can create movements in various directions, and
The ball 5 does not fall out. The problem in this case is that the component ratio of the machining cost is large, and the reason is that the sliding torque after caulking needs to be within a predetermined range, and thus machining accuracy is required.

When the suspension arm is formed by forging, it is possible to integrally form the ball joint portion with a simple shape. In this case, as shown in FIG. 14, the inner surface of the holding portion 6 is processed, and then the spherical shaft body 4 is assembled. The problem is that the processing cost is high. When manufacturing the arm part and the ball joint part as separate bodies, in the case of a complicated shape that is difficult to forge, or by comparing the processing cost of an integrated product and the press-fitting cost of a separate body, etc. This is the case where it can be manufactured at a lower cost.

Next, the bush mounting portion is shown in FIG.
The bush shown in 5 is used. Conventionally, it was press-fitted into the machined inner cylinder part, but since the bush mounting part is a straight cylinder, the deformation resistance (resistance force when the hole tries to widen) is large, so that the inner cylinder part is ± 0. It was necessary to have a dimensional accuracy of about 05 mm.

In Japanese Utility Model Laid-Open No. 57-134907, an improvement is made on an automobile forged link arm 71 having a bush mounting portion 2 at a substantially central portion and a ball joint portion 1 and a shaft portion 74 at both ends. is suggesting. That is, the feature of the proposal of the publication is that, as shown in FIG. 17, the bush mounting portion 2 is manufactured by a split type in which a separate bracket 75 is press-fitted to be integrated, whereby a through hole 79 for rubber bush mounting is formed. This is intended to reduce the molding surplus at the bush mounting portion of the forged material in the solid rod-shaped arm 72 in which is formed and to simplify the inner peripheral surface finish.

Further, in FIG. 17, the ball joint portion 1 has a socket portion 76 on one end side of the arm 72.
The ball joint portion 1 includes a ball seat 77 that rotatably holds the ball 5 of the ball stand 73 on the inner periphery of the socket portion 76, and a closing plate 7 that is caulked and fixed so as to close the bottom portion.
8 and a dust cover 25 that seals the upper part.

With respect to the shaft portion, as shown in FIG. 16, the bush of the shaft portion that is press-fitted into the shaft is usually made of rubber, and the outer peripheral surface of the shaft is machined in order to mount it. Has been done. For this reason, the removal force of the bush becomes small, and it is difficult to prevent the bush from coming off.

[0011]

In the prior art,
The ball joints and other parts were machined from the forged one piece. Then, in the ball joint portion, the inner surface of the holding portion that holds the ball of the ball-shaped shaft body is machined (the surface roughness is 20S to 50S, with dimensional variation ±
0.2 mm), and a resin sheet-shaped outer wrapping material was fitted therein. In addition, the bush mounting part is machined because it is necessary to control the dimensional tolerance of the inner diameter surface of the outer cylinder of the bush mounting part in order to prevent the bush from being pressed in and coming off. It was a factor of the increase in production cost. Further, since the shaft of the shaft portion is machined, there is a problem that the number of manufacturing steps increases and the manufacturing cost also increases.

Conventionally, a forged or cast article has a large surface roughness (usually, the surface roughness of the casting surface is 100 S to 200 S), and at the same time, there is a dimensional variation of ± 0.5 mm, and a ball at the ball joint part or It was necessary to machine the holding portion that holds the ball and the outer packaging material, the inner diameter surface of the bush mounting portion, and the shaft of the shaft portion.

The present invention has been made in view of the above problems, and an object thereof is to provide an inner surface of a bush mounting portion for mounting a bush, an inner surface of a holding portion of a ball joint portion, a shaft of a shaft portion, and the like. The purpose of the present invention is to provide a suspension component that can be applied with a substantially molded surface with large surface roughness and dimensional variation by abolishing the mechanical processing of, while maintaining strength and at low cost and having performance equivalent to or higher than conventional ones. .

The term "substantially molded skin" in the present invention means a cast skin or a forged skin in which a suspension component formed as a one-piece casting or a one-piece forging is not machined. Meaning, substantially molded skin means
Includes cast skin after the entire surface of the cast monolith has been dismantled from the mold, and skin after forging, as well as cases where the skin of the monolith has been partially shaved by burr or distortion removal. Then
It also includes the case where the surface roughness of the skin of these monoliths is improved by coining as compared with the surface roughness of the skin after casting or after forging. In addition, the inner diameter surface of the bush mounting portion, the inner surface of the holding portion of the ball joint portion, the shaft of the shaft portion, etc., which were conventionally machined, are skins of casting or forging, and parts that are partially machined in other parts If any, it is included in the substantially molded skin of the present invention. In addition, as the substantially molded surface of the present invention, it is desirable that the shape of the integrally formed product can be freely selected and that the surface of the integrally formed product is a cast product for a suspension component having a complicated shape.

[0015]

Means for Solving the Problems As a result of earnest research in view of the above objects, the inventors of the present invention have paid attention to the following items (1) to (3) and devised them to form a suspension component as an integral body, thereby forming a substantially molded skin. The present invention has been completed with the idea that strength and performance can be secured even when manufactured by. The arm portion forms a suspension component by being formed singly or integrally with a bush mounting portion, a ball joint portion, and a shaft portion. A recess is formed in the axial direction in the inner diameter surface of the bush mounting portion (preferably, it is not formed at both ends but only at the center, since rust may be generated by water if there are recesses at both ends). As a result, the elastic property can be utilized, and the dimensional tolerance of the bush mounting portion can be made relatively wide. By forming a concave portion in the axial direction (from the outer diameter surface side toward the inner diameter surface) on the outer diameter surface of the bush mounting portion, the elastic property can be utilized. In the shaft part, the shape to prevent the shaft from coming off,
Make an axial recess on the inner cylinder surface of the bush. In the ball joint, it can be dealt with by injecting a resin or a metal having a low melting point to hold the ball of the shaft body with a ball.

The suspension component of the present invention is characterized in that suspension components such as a suspension arm and a cross member in which a bush mounting portion is provided at a predetermined portion of the arm portion are integrally formed. Also, the suspension component is characterized in that the bush mounting portion and the ball joint portion are formed as an integral body provided at respective predetermined portions of the arm portion. Further, the suspension component is characterized in that the bush mounting portion and the shaft portion are formed as an integral body provided at respective predetermined portions of the arm portion. Further, the suspension component is characterized in that the bush mounting portion, the ball joint portion, and the shaft portion are formed as an integral body provided at respective predetermined portions of the arm portion. Further, the one body is characterized by having a substantially molded skin.

By forming the suspension component of the present invention as an integral body and applying it with a substantially molded skin, it is possible to maintain the strength and to secure the performance equal to or higher than the conventional one. Since machining is not required, the number of manufacturing steps and cost can be reduced.

[0018]

The present invention will be described with reference to the drawings by the following embodiments. (Embodiment 1) FIG. 1A shows a ball joint portion 1, a bush mounting portion 2 and a shaft portion 3 in an embodiment of the present invention.
FIG. 3 is a front view of an arm-shaped suspension component having and in a predetermined portion of the arm portion 20. 1 (b) and 1 (c) are sectional views of the ball joint portion 1 taken along the line YY, which has a void surrounded by a holding portion 6 having a closed bottom. In FIG. 1C, a metal or a resin having a melting point lower than that of the material of the holding portion 6 is injected into a space formed by the sphere 5 of the sphere shaft 4 and the inner surface of the holding portion 6, and the holding portion 6 The upper open end 9 of FIG. FIG. 1D is a side view taken along the line XX of FIG. FIG. 1E shows a state in which the bush 12 is press-fitted into the shaft 13.

Reference numeral 2 in FIG. 1A shows a bush mounting portion. The thick wall portion 15 of the bush mounting portion has an inner diameter surface not provided with a straight cylinder but with a recess 30 in the axial direction provided at the center. It has the effect of relieving stress by deformation.
By forming a recess in the axial direction in the inner diameter surface of the thick portion 15 of the bush mounting portion, the deformation margin in the circumferential direction due to elastic deformation becomes larger than that in the case of a straight cylinder.
Large variation in surface roughness and size Bushing can be pressed in even with the surface of the casting and the pulling force is large. The recess in the axial direction can be formed over the entire length in the axial direction, but it is desirable to form it only in the center without forming it at both ends. FIG. 1F is a sectional view in which the bush 12 is mounted on the bush mounting portion 2. FIG. 3 shows a modification of the bush mounting portion 2 of FIG. 1 (f).
It is a longitudinal cross-sectional view in the case where the outer diameter surface is a straight cylinder.

As shown in FIG. 2, the ball joint portion 1 is formed by positioning a ball-shaped shaft body 4 made of alloy steel in which a ball 5 and a shaft portion 11 are integrally formed, and a holding portion 6. An outer wrapping material (resin or low melting point metal) 7 for holding the sphere 5 was injected and solidified in the void, and the upper open end 9 of the holding portion 6 was caulked by a caulking machine 10. The part to be caulked may be the entire circumference of the upper open end 9 or a part thereof. The point is to fix the injection-solidified outer wrapping material 7 so that the sphere 5 does not come off due to an external force acting on the ball-shaped shaft body 4. Is to The outer packaging material 7
Before injecting, the upper open end 9 may be caulked, and the resin or the low melting point metal may be injected through an injection hole (not shown) provided in the side wall or the bottom of the holding portion 6. The holding portion 6
The material used was spheroidal graphite cast iron with excellent ductility. Unlike the conventional technique in which the ball-shaped shaft body is fitted to the resin sheet-shaped outer packaging material solidified by injection molding and inserted into the machined inner surface of the holding portion, in the present invention, the outer packaging material is injected and solidified. Therefore, it is not necessary to machine the inner surface of the holding portion, and it is possible to apply it even to a casting surface. In this embodiment,
Although the example of the suspension component having the bush mounting portion, the ball joint portion and the shaft portion is shown, depending on the type of the suspension component, the bush mounting portion alone or the bush mounting portion and the ball joint portion or the shaft portion may be used. Good.

(Embodiment 2) FIG. 4 is a cross-sectional view showing corrugated concavities and convexities formed on the inner diameter surface of a bush mounting portion formed as an integral body of a casting. Unlike a cylindrical inner diameter surface that is straight in the axial direction, there is room for deformation in the corrugated bottom space formed on this inner diameter surface, and if you try to press fit a bush (not shown) Since the contact area is reduced and the convex portion is plastically deformed, the press-fitting pressure of the bushing may be relatively small even if the surface roughness and the dimensional variation are large as in a casting surface, and the press-fitting work is easy.

(Embodiment 3) FIG. 5 is a cross-sectional view of the bush mounting portion 2, in which four axial recesses (from the outer diameter surface side to the inner diameter side) are provided at four locations on the outer diameter surface of the thick portion 15 of the bush mounting portion. (In the direction of the surface) and at the same time four axial recesses (in the direction from the inner diameter surface to the outer diameter surface) are provided in the inner diameter surface. In this way, the outer diameter surface or inner diameter surface of the bush mounting part,
Alternatively, when the inner and outer diameter surfaces are provided with a portion having a small deformation resistance, the bush can be press-fitted and mounted even with the casting surface without machining. In this case, the bush mounting portion has an interference fit on the inner diameter surface, so that the bush is firmly mounted. In the recess in the axial direction provided on the inner diameter surface or the outer diameter surface, the deformation margin in the circumferential direction is large, and the deformation is facilitated, which contributes to the stress relaxation of the input from the outside. The inner diameter surface of the bush mounting portion is deformed as shown by the dotted line in FIG. 5B to relieve the stress. FIG. 5 (c)
Shows the easiness of deformation of the bush mounting portion of the present invention when an external force is applied. It can be seen that the amount of deformation of the bush mounting portion of the present invention is large when the same pressure input is applied. Therefore, the pressure of the press-fitting of the bush may be relatively small even if the casting surface has large surface roughness and dimensional variation, and the press-fitting work is easy. It should be noted that the bushing is fitted tightly because it becomes a tight fit, and the bushing does not come off easily.

(Embodiment 4) FIG. 6 is a cross-sectional view of a bush showing an embodiment applied to the shaft portion of the suspension component of the present invention. A recess in the axial direction was provided on the inner cylindrical surface of the bush 12, and the shaft of the casting surface was press-fitted. After the shaft is press-fitted, it becomes a tight fit, the mounting becomes strong, and there is a void formed by the concave portion 14 of the bush 12, so that the shaft is not machined and surface roughness and dimensional variation are large. Even with the casting surface, the deformation of the bush in the circumferential direction is larger than that of the straight inner cylindrical surface, and the press-fitting pressure may be relatively small, and the press-fitting operation is easy.

(Embodiment 5) FIGS. 7 (a), 7 (b) and 7 (c) show various shapes of the elastic body of the bush 12 between the thick portion 15 and the bush inner cylinder 16 in the bush mounting portion. It is a longitudinal cross-sectional view showing a state of being mounted by press fitting or vulcanization. In addition, (e) and (f) of FIG. 8 and (g) of FIG.
(H) is a similar vertical sectional view. In this way, by selecting various shapes of the bush mounting portion by casting, it is possible to prevent the bush from coming off when an external force in the axial direction is input.

(Sixth Embodiment) FIGS. 10 (m), 10 (n), and 11 are side views showing various slip-out preventing shapes of the shaft 13 in the shaft portion of the present invention. By forming the shaft 13 which is an integral part of the casting into such a shape, after the bush 12 (not shown) is press-fitted on the shaft 13, even if an external force acts, the resistance at the mutual contact surfaces is large. Therefore, the prevention of slipping out is made safer.

(Embodiment 7) (a) and (b) of FIG.
Is the bush 12 on the shaft 13 of the shaft portion of the present invention.
FIG. 3 is a vertical cross-sectional view in which is mounted. An elastic bush 12 was formed by vulcanization 18 so as to wrap the shaft 13 having a slip-prevention shape in which a portion having a diameter larger than the tip end portion or the root portion of the shaft 13 was formed by tapering in the approximate center of the shaft 13. In addition to the taper, an arc shape or an uneven shape may be used. In addition, it may be formed in various shapes such as a triangle and a quadrangle. By forming such various shapes, the frictional resistance between the shaft 13 and the bush 12 can be improved, and the shaft 13 can be prevented from coming off. In FIG. 12B, the bush having the shape shown in FIG. 12A is formed as the split type bush 19.

In the above-mentioned embodiment, the cast integral body is described, but when the shape of the integral body is not complicated, it can be formed as a forged integral body. Further, as the suspension component of the present invention, on the surface of the integral body having the above-described substantially molded skin, in order to prevent rust and reduce frictional resistance to facilitate press-fitting of the bush, dripping or cationic electrodeposition coating is performed. It may have a resin film such as an epoxy resin formed by the above.

[0028]

As is apparent from the above description, the suspension component of the present invention is formed as an integral body having the bush mounting portion, the ball joint portion, and the shaft portion, all or some of which are provided in predetermined portions of the arm portion. The surface roughness without machining is large, and it can be applied even with the molding surface having dimensional variation, and the cost can be reduced by significantly reducing the processing man-hours while maintaining the strength.

[Brief description of drawings]

FIG. 1 is an overall explanatory view including a front view and a side view of an arm-shaped suspension component of the present invention.

FIG. 2 is a vertical sectional view of a ball joint portion of the suspension component of the present invention.

FIG. 3 is a vertical cross-sectional view of another modified example of the bush mounting portion of the present invention.

FIG. 4 is a transverse cross-sectional view of the bush mounting portion of the present invention, showing a state where corrugated irregularities are provided on the inner diameter surface of the thick portion of the bush mounting portion.

FIG. 5 is a cross-sectional view (a) of the bush mounting portion showing a state in which a concave portion is partially provided on the inner diameter surface and the outer diameter surface of the thick portion of the bush mounting portion of the embodiment of the present invention, and its deformed state ( FIG. 6B is a diagram showing a deformation amount corresponding to the magnitude of b) and the pressure input.

FIG. 6 is a view showing a bush in which a concave portion is provided on an inner cylindrical surface.

7 (a), (b) and (c) are longitudinal sectional views showing a state in which a bush is attached to the bush attaching portion of the present invention.

8 (e) and 8 (f) are vertical cross-sectional views showing a state in which the bush is mounted on the bush mounting portion of the present invention.

9 (g) and 9 (h) are longitudinal sectional views showing a state in which the bush is mounted on the bush mounting portion of the present invention.

FIG. 10 is a side view showing a shaft shape of a shaft portion according to an embodiment of the present invention.

FIG. 11 is a side view showing another embodiment of the shaft shape of the shaft portion of the present invention.

12A and 12B are vertical cross-sectional views showing a state in which a bush is formed by vulcanization on the shaft of the shaft portion of the present invention.

FIG. 13 is an overall explanatory view including a plan view of a conventional sheet metal arm-shaped suspension component.

FIG. 14 is a vertical cross-sectional view of a ball joint portion of a conventional example.

FIG. 15 is a vertical sectional view of an assembled bush of a conventional example.

FIG. 16 is a front view (a) and a vertical sectional view (b) of a bush used in a shaft portion of a conventional example.

FIG. 17 is a sectional front view of the link arm of the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ball joint part 2 Bush mounting part 3 Shaft part 4 Shaft body with ball 5 Ball 6 Holding part 7 Outer packaging material 8 Color 9 Caulking part 10 Caulking machine 11 Shaft part with ball 12 Bush 13 Shaft 14 Bush recess 15 Thick part of the bush mounting part 16 Bush inner cylinder 18 Vulcanization 19 Split type bush 20 Arm part 25 Dust cover 30 Bush mounting part inner surface concave part

Claims (8)

[Claims] 1. A suspension component, wherein the bush mounting portion is formed as an integral body provided at a predetermined portion of the arm portion, and the integral body has a substantially molded skin. 2. A suspension component, characterized in that the bush mounting portion and the ball joint portion are formed as an integral body provided at respective predetermined portions of the arm portion, and the integral body has a substantially molded skin. 3. The bush mounting portion and the shaft portion are formed as an integral body provided at predetermined portions of the arm portion, respectively.
A suspension component, wherein the one-piece has a substantially molded skin. 4. A suspension component, wherein the bush mounting portion, the ball joint portion, and the shaft portion are formed as an integral body provided at predetermined portions of the arm portion, and the integral body has a substantially molded skin. 5. The suspension component according to claim 1, wherein an inner diameter surface of the bush mounting portion has a recess in the axial direction. 6. A resin or a low melting point resin is provided in a space formed between a ball of a shaft body with a ball attached to a holding portion of the ball joint portion and an inner surface of the holding portion holding the ball. The suspension component according to claim 2, 4 or 5, wherein metal is injected and the upper open end of the holding portion is caulked to the ball side. 7. The suspension component according to claim 3, wherein the shaft of the shaft portion has a shape that prevents the shaft from coming off. 8. The suspension component according to claim 3, wherein a bush having an axially concave portion on the inner cylindrical surface is press-fitted to the shaft of the shaft portion.