JPH0680952U - Diaphragm for air spring - Google Patents

Abstract

(57) [Summary] [Purpose] To enhance durability and flexibility, and at the same time, to sufficiently reduce the manufacturing cost. In a diaphragm formed by spirally burying a band-shaped reinforcing member in a cylinder made of rubber or a rubber-like elastic body in the length direction of the cylinder 9, a reinforcement positioned at least at the outer side when the diaphragm is used. The member 9b is embedded without overlapping in the length direction of the tubular body 9.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention In this invention, a strip-shaped reinforcing member is embedded spirally in the lengthwise direction of a cylinder in a cylinder made of rubber or a rubber-like elastic body. The present invention relates to an improved air spring diaphragm. 2. Description of the Related Art Diaphragms of this type are being widely used for automobile suspensions as shown in FIG. 1, for example. This suspension 1 fixes an outer shell 4 to a rod 3 of a shock absorber 2, and a tubular air spring is provided at an end portion of the outer shell 4 and an intermediate portion or an end portion of an outer cylinder 5 of the shock absorber 2. Each end portion of the diaphragm 6 is fixed. Here, the diaphragm 6 folded back toward the opposite side of the outer shell 4 so as to have a substantially U-shaped cross section forms a closed space between it, the outer cylinder 5, and the outer shell 4, A spring action is provided in cooperation with the compressed air enclosed therein. A conventional air spring diaphragm used for such an application is, for example, as shown in FIG. 2, a rubber cylindrical body 8 having a substantially truncated cone shape as a whole and its axis line XX. On the other hand, the belt-shaped reinforcing members 9a and 9b, which have an angle of intersection of 30 ° to 60 ° and form two layers inside and outside, are embedded symmetrically and spirally. Further, when the reinforcing members 9a and 9b are embedded, in order to prevent the flat body 8 from being punctured, and further to prevent the manufacturing accuracy from being deteriorated due to the winding deviation of the reinforcing members 9a and 9b, each of the tubular members 8 is axially moved. The width direction end portions of the reinforcing members 9a and 9b are overlapped with each other in a width of 1 to 10 mm. Therefore, according to such a conventional technique, the rigidity of each overlapping portion of the reinforcing members 9a and 9b becomes higher than that of the other portions when used, and this rigidity change in the longitudinal direction of the tubular body 8 is caused. Causes local stress concentration on the diaphragm, which often causes damage, and also has a problem that the reinforcing members 9a and 9b are exposed from the cylindrical body 8 to cause air leakage. Therefore, by increasing the wall thickness of the tubular body 8 as a whole to increase the rigidity of the diaphragm and preventing the reinforcement members 9a and 9b from being exposed, the variation in the rigidity of the tubular body 8 in the longitudinal direction can be reduced. In addition, attempts have been made to prevent air leakage and improve the durability of the diaphragm. However, when the thickness of the cylindrical body 8 is increased and the diaphragm is used as described with reference to FIG. 1, the diaphragm, especially in the vicinity of the inner and outer peripheral surfaces, is severe. As it is bent and deformed, the radius of curvature of the portion near the inner peripheral surface of the U-shaped folded-back portion becomes particularly small. Therefore, the fibers forming the reinforcing members 9a and 9b, and the fibers and the rubber material around them Since the fibers and rubbers are seriously damaged by the friction with, the bending fatigue of the diaphragm is caused at an early stage, and there is a problem that an air spring having a good riding comfort cannot be provided. [0006] The present invention advantageously solves the above-mentioned problems of the prior art, and in particular, at the time of using the diaphragm, the reinforcing member located at least on the outer side is provided with a long tubular member. By embedding it in the cylinder without overlapping in the depth direction, it is possible to prevent the reinforcing member from being exposed from the rubber material and to prevent the diaphragm from being damaged due to the change in rigidity of the cylinder in the length direction. (EN) Provided is a diaphragm capable of reducing the thickness of a tubular body, preventing damage to the reinforcing member fibers and rubber, and sufficiently improving the riding comfort. The present invention will be described below with reference to the drawings. FIG. 3 is a partial sectional view showing an embodiment of the present invention. In this example, as described with reference to FIG. 2, for example, two layers of inner and outer reinforcing members 9a and 9b are spirally formed in a rubber tubular body 8. It is buried in. Here, the outer portion of the reinforcing member 9b located outside is shown as a cross section, but the reinforcing member 9a (not shown) located inside extends in a symmetrical manner with the reinforcing member 9b with respect to the axis XX. For example, among strip-shaped reinforcing members 9a and 9b formed by weaving nylon fibers in a comb shape and further coating an elastic body such as rubber, in this example, the reinforcing member 9b arranged particularly on the outer side is a long member of the cylindrical body 8. In the spiral direction, the reinforcing members 9b are not overlapped in the vertical direction, but are preferably spaced apart from each other by about 0.2 to 5 mm as shown in the enlarged sectional view in FIG. Each of the outer rubber layers 8a on the outer side is vulcanized and adhered. When the diaphragm 6 is used, the left end side of FIG. 3 is folded inward to be fixed to the outer cylinder 5, and the right end portion of the figure is fixed to the outer shell 4, so that the diaphragm 6 can be used outside. The reinforcing member 9b arranged at is located outside. On the other hand, when the diaphragm 6 is used, the left end in the figure is fixed to the outer cylinder as it is, and the right end is folded back to the outer shell 4 to be fixed to the outer shell 4. In this case, the reinforcing member 9a is positioned in the same manner as the above-mentioned reinforcing member 9b and vulcanization adhesion is performed. Although not shown, it goes without saying that the inner reinforcing member 9a may be similarly positioned. According to the diaphragm in which the reinforcing member 9b is embedded in this manner, since the reinforcing member 9b does not overlap in the width direction, the rigidity in the length direction becomes relatively uniform, so that stress concentration is relaxed. This improves the durability of the diaphragm. On the other hand, even if the wall thickness of the cylindrical body 8 is thinned, there is no risk of air leakage due to the exposure of the reinforcing members 9a and 9b, and the reduction of this wall thickness reduces the rigidity of the diaphragm as a whole and causes deformation thereof. Since the difference in the amount of deformation between the inner and outer peripheral surfaces is reduced, excellent riding comfort of the vehicle is ensured, and damage due to friction between the reinforcing member 9b and the rubber material is effectively prevented. By the way, the results of comparing the diaphragm according to the present invention and the conventional diaphragm in a bench durability test are as follows. Conditions: Pressure 8.5 kg / cm ² gage, temperature 75 ℃, frequency 3.5Hz, stroke ± 50mm [0013] Results [Table 1] As is apparent from Table 1, the diaphragm of the present invention provides at least three times the durability of the conventional product. Although the invention has been described with reference to the illustrated example, the reinforcing member may be made of a fiber other than nylon fiber. Therefore, according to the present invention, by eliminating the overlap of the reinforcing members, it is possible to obtain a diaphragm having excellent durability and sufficient riding comfort, and to use raw materials. The cost can be reduced and the cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional view showing an applied state of a diaphragm. FIG. 2 is a side view showing a conventional example. FIG. 3 is a partial sectional view showing an embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of FIG. [Explanation of reference numerals] 8 Cylindrical bodies 9a, 9b Reinforcing member

Claims (1)

[Claims for utility model registration] 1. In a diaphragm formed by spirally burying a belt-shaped reinforcing member in a cylinder made of rubber or a rubber-like elastic body in the length direction of the cylinder, when using this diaphragm, A diaphragm for an air spring, characterized in that at least a reinforcing member located on the outer side is embedded without overlapping in the longitudinal direction of the tubular body.