JP3502108B2 - bush - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bush used for stabilizing a shaft used in a machine product such as an automobile. 2. Description of the Related Art Generally, a bush is formed of an inner cylinder and an outer cylinder which are arranged concentrically, and a vibration-proof rubber member provided therebetween. Is embedded with a tubular intermediate plate (inter-ring) for partitioning the plate into an inner peripheral portion and an outer peripheral portion. In such a bush,
For example, in the invention disclosed in Japanese Utility Model Application Laid-Open No. 63-20538, it is proposed to form notches at both ends of the inter-ring alternately across the circumferential surface at intervals in the circumferential direction. ing. [0003] Such a bush, after applying an appropriate surface treatment adhesive to each pipe material forming the inner cylinder and the outer cylinder inter-ring, these are arranged concentrically and set in a middle mold, and The mold is formed by closing the mold and the lower mold, filling the space between the inner cylinder and the outer cylinder with raw rubber, and performing press vulcanization. After molding, the outer cylinder is drawn (usually about 5% of the outer diameter) to improve durability,
Next, polishing, rust prevention treatment and the like are performed to obtain a product. [0004] However, in the above-mentioned prior art bush, since the notches are provided at both cylindrical ends of the inter ring, the inter ring is firmly attached to the vibration-proof rubber body. However, the notch formed at one end of the cylinder and the notch formed at the other end are related to the fact that their positions are alternated. In addition, there is a problem that setting in a mold is troublesome in press vulcanization. In addition, there is also a problem that the molded product is deformed into an elliptical shape due to the drawing process performed after the molding, and the obtained bush has a directional spring characteristic. An object of the present invention is to provide a bush that can be easily set in a mold at the time of molding and that is effectively prevented from being deformed during drawing. is there. According to the present invention, an anti-vibration rubber member is provided between an inner cylinder and an outer cylinder which are arranged concentrically. In a bush in which a tubular intermediate plate that divides the inner peripheral portion and the outer peripheral portion is buried, at both ends of the tubular intermediate plate, at positions corresponding to each other, at substantially equal intervals in the circumferential direction. A bush characterized in that at least three notches or slots extending in the axial direction are formed at each end. [0008] In the present invention, in the present invention, the both ends of the cylindrical intermediate plate (hereinafter sometimes referred to as "inter-ring" in this specification) are provided in the circumferential direction. It is an important feature that the notches or slots extending axially at substantially equal intervals correspond to one another. That is, since a notch or a long hole is formed at the opposite cylindrical end with respect to one notch or a long hole formed at one cylindrical end, the pressing process is performed. During the vulcanization, the setting in the mold becomes extremely simple. In the bush of the prior art, the number of cutouts formed at each end of the cylinder of the inter ring is two.
Since the peripheral surface of the inter ring is provided so as to be divided into two, the elastic modulus of the vibration isolating rubber body has directivity (the spring constant of the notch forming portion decreases). For example, when a load-deflection curve is created for a vibration-isolating rubber body in a prior art bush, a considerable deviation occurs between a curve in the direction of the notch forming portion and a curve in a direction perpendicular thereto. For this reason, the prior art bush has a problem that it is likely to cause inconvenience such as deformation due to drawing work performed after molding. On the other hand, according to the present invention, at least three notches or long holes are provided at each end of the cylinder of the inter ring, so that the directionality of the elastic modulus is effectively improved. For example, the load-deflection curve is almost the same in any direction. Therefore, it is possible to effectively eliminate deformation and the like during drawing. The above-described advantages of the present invention can also be achieved by providing the elongated holes in a mesh shape. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to specific examples shown in the accompanying drawings. In FIG. 1 showing a side cross section of the bush of the present invention, the bush is composed of an inner cylinder 1 and an outer cylinder 2 which are arranged concentrically, and a vibration-proof rubber member 3 provided between them. An inter-ring 4 is embedded in the vibration-proof rubber body 3, and the vibration-proof rubber body 3 has an inner peripheral portion 3a.
And an outer peripheral portion 3b. FIG. 2 shows a preferred example of an inter-ring 4 used in the bush of the present invention.
Are provided at substantially equal intervals, respectively. Therefore, the directionality of the elastic modulus is effectively improved. In this case, the number of the cutouts 4a provided at each cylindrical end portion may be at least three, and is four in the drawing, but may be five or more. If the number is two, as described above, the elastic modulus has directionality. In addition, in the present invention, since the elastic modulus has no directionality, deformation during drawing can be effectively prevented, and when the shaft is pressed into the bush, the shaft is slightly decentered and eccentric. However, if the elastic modulus has directionality, it is necessary to press-fit the shaft so that it is centered with high precision. In the inter-ring 4, the notch 5a provided at one cylindrical end and the notch 5a provided at the other cylindrical end correspond to each other in a corresponding positional relationship. It is in. If these do not correspond to each other and are provided alternately, it becomes easy to set the bush in the mold when molding the bush. In the present invention, a slot may be provided instead of the notch, and this embodiment is shown in FIG. In the inter ring 4 of FIG. 3, a long hole 5b is provided instead of the notch 5a of FIG. Also in this embodiment, the slot 5
The restrictions on the number of positions b are exactly the same as in FIG. According to the present invention, at the time of molding the bush, it can be easily set in the mold, and the elastic modulus of the vibration-proof rubber has no directionality. Deformation during drawing can be effectively prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view simply showing the entire structure of a bush of the present invention. FIG. 2 is a view showing a preferred example of an inter-ring used for the bush of the present invention. FIG. 3 is a view showing another example of an inter ring used for the bush of the present invention. FIG. 4 is a view showing still another example of an inter ring used for the bush of the present invention.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16F 1/38

Claims (1)

(57) [Claim 1] An anti-vibration rubber body is provided between an inner cylinder and an outer cylinder which are concentrically arranged, and the anti-vibration rubber body has an inner peripheral portion. And a bushing in which a tubular intermediate plate that divides the outer peripheral portion is embedded. At both ends of the tubular intermediate plate, shafts are provided at positions corresponding to each other at substantially equal intervals in the circumferential direction. A bush characterized in that at least three notches or slots extending in the direction are formed at each end.