JPS633178B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic shock absorber equipped with a retainer guide having a structure that can sufficiently withstand, for example, full extension load and pressing force.

Generally, in the case of hydraulic shock absorbers, etc., as shown in Fig. 1, an outer flange is used as a means to guide and support a valve 3, etc. located at the top of a piston 2 attached to the tip of a rod 1. A retainer guide 4 having a hollow cylindrical shape is provided.

By the way, this retainer guide 4 is similar to the rod 3.
As the retainer guide 4 itself is subjected to axial pressing force and stretching force due to continuous operation and high-speed operation, it is necessary to form it from a material that can withstand these effects.

However, this type of conventional retainer guide is
Sintered metal was used as the material for forming the retainer guide because it was relatively easy to form and had a high oil sealing property, so for example, sudden extension loads were applied to the retainer guide. In such cases, the disadvantage is that the sintered metal itself is susceptible to deformation and breakage due to its properties. In addition, products formed from this sintered metal may require special forming equipment when molding the product, increasing manufacturing costs. Another problem was that retainer guides were expensive.

This invention was made in view of the above circumstances, and a retainer guide in the shape of a hollow cylinder having an outer flange is made into a cylinder by cutting a round bar-shaped wire made of a plastically deformable soft metal in its radial direction. the cylindrical body is formed, and the periphery of both ends of the cylindrical body is cut and hemmed, and the cylindrical body is pressed by a pressing member along the axial direction of the cylindrical body from one end side of the cylindrical body with the hemmed ends. The process of forming a recess at one end of the cylinder and the process of forming a recess at the other end of the cylinder by pressing from the other end side of the cylinder with a pressing member along the axial direction of the cylinder are repeated in a cold state to form a cylinder. A cylinder is formed by punching out the center and forming a circular hole in the center of the cylindrical body, and a hole with a circular cross section and an inner diameter slightly smaller than the outer diameter of the cylinder is formed at one end and is coaxial with the hole. The shaft of the press upper die, which is slidably provided with a shaft that fits tightly into the circular hole at the center of the cylinder, is placed on the press stage with one end in contact with the cylinder. By fitting into the central circular hole and cold pressing the cylinder on the press stage with the press upper mold to plastically deform the outer periphery of the cylinder and forming an outer flange at one end of the cylinder. It is an object of the present invention to provide a method for manufacturing a retainer guide in a hydraulic shock absorber, which can sufficiently withstand the above-mentioned extension load and pressing force, and can manufacture an inexpensive retainer guide.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a hydraulic shock absorber according to the present invention, and a retainer guide 5 used therein.
As shown in FIG. 3, the retainer guide 5 is made up of a cylindrical part 6 and an outer flange 7 formed at one end of the cylindrical part 6.The process of manufacturing this retainer guide 5 from soft metal will be described below. This will be explained in sequence with reference to the following FIGS. 4a to 4j.

First, a round bar-shaped wire rod 10 made of a plastically deformable soft metal such as iron as shown in FIG.
get.

Next, the periphery of one end of this cylindrical body 11 is cut and edged as shown in FIG. Obtain body 11.

Next, this cylindrical body 11 is pressed from one end side along the axial direction of the cylindrical body 11 with a punch or the like to form a recess 12 as shown in FIG. Then, press along the axial direction of the cylindrical body 11 with a punch or the like to form a recess 13 as shown in FIG. A hole 14 is formed to obtain a hollow cylindrical body 15 with a slightly thick wall as shown in FIG.

Next, as shown in FIG. (This press upper die 17 has a shaft rod 17a that fits closely into the circular hole 14 of the hollow cylindrical body 15, and is adapted to slide this shaft rod 17a in the axial direction, and the above-mentioned hollow cylinder body First, the shaft rod 17a of the hollow cylindrical body 15 is inserted into the circular hole 14 of the hollow cylindrical body 15. After fitting, the hollow cylindrical body 15 is placed on the stage 16 using the press upper die 17.
Press it to the side and squeeze it. Then, the outer circumference of the hollow cylindrical body 15 is plastically deformed and pushed in the pressing direction, undergoes deformation as shown in Figure i, and finally by applying further pressure. A hollow cylindrical body 19 with an outer flange 18 as shown in j is obtained.

After the hollow cylindrical body 19 having the outer flange 18 is obtained in this way, the outer circumferential surface and inner circumferential surface thereof may be polished to adjust the overall surface roughness, dimensional accuracy, etc. , a hollow cylindrical retainer guide 5 having an outer flange as shown in FIG. 2 can be obtained.

By the way, since the retainer guide 5 formed in this way is formed by cold forging iron, it is possible to effectively utilize the viscosity of iron itself, and therefore it can be formed from conventional sintered metal. Compared to conventional retainer guides, the material's ability to withstand tensile loads is clearly superior. In particular, in this invention, during the molding, that is, when forming the outer flange 18 at one end of the hollow cylindrical body 15 using the press upper mold 17, the outer circumference of the hollow cylindrical body 15 is firmly pressed and plastically deformed. Since the outer flange 18 is formed by this, the metal crystal bond is strong, and the strength against the tensile load or pressing force is further increased. Furthermore, when forming this hollow cylindrical body 15, the circular hole 14 is punched out by pressing alternately with a punch from both ends, so that the flesh part of the hollow cylindrical body 15 is forged, and therefore its The strength is increased, and the shaft rod 17a of the press upper die 17 is
The hollow cylindrical body 15 is fitted into the circular hole 14 at the center of the hollow cylindrical body 15 placed on the press stage 16 with one end in contact with the press stage 16, and the hole having an inner diameter slightly smaller than the outer diameter of the hollow cylindrical body 15 is inserted into the hollow cylindrical body 15. Since the outer periphery of the hollow cylindrical body 15 is pressed and plastically deformed, the cylindrical part 6 and the outer flange 7 of the retainer guide can be formed almost simultaneously and into accurate shapes and dimensions. The manufacturing efficiency of the retainer guide can be improved while maintaining strength.

As detailed above, according to the method for manufacturing a retainer guide for a hydraulic shock absorber of the present invention, a round bar-shaped wire made of a plastically deformable soft metal is cut in the radial direction to form a cylindrical body, and the cylindrical body is A step of cutting and edging the periphery of both ends of the body, and forming a recess at one end of the cylindrical body by pressing with a pressing member along the axial direction of the cylindrical body from one end side of the cylindrical body with both ends edged. and forming a recess at the other end of the cylinder by pressing with a pressing member along the axial direction of the cylinder from the other end side of the cylinder are repeated in the cold to punch out the center of the cylinder. A cylinder is formed by forming a circular hole in the center of the body, and a hole with a circular cross section and an inner diameter slightly smaller than the outer diameter of the cylinder is formed at one end, and a circle at the center of the cylinder is formed coaxially with the hole. The shaft rod of the press upper die, which is slidably provided with a shaft rod that fits tightly into the hole, is fitted into the circular hole at the center of the cylinder, which is placed with one end in contact with the press stage. However, since the cylinder on the press stage is cold pressed by the press upper die to plastically deform the outer periphery of the cylinder and form an outer flange at one end of the cylinder, (a) plastic deformation is possible. The retainer guide is formed by cold forging from a round bar-shaped wire rod made of soft metal, so the viscosity of the material, the strong metal crystal bond of the material due to cold forging, and the work hardening due to plastic deformation. As a result, the tensile strength, compressive strength, and shear strength are significantly higher than that of conventional retainer guides made of sintered metal, and the overall durability is greatly improved, and the tensile strength, compressive strength, and shear strength are significantly increased. (b) Fit the shaft rod of the upper press die into the circular hole at the center of the cylinder, which is placed on the press stage with one end in contact with it, and Since the small inner diameter hole is fitted into the cylinder and the outer periphery of the cylinder is pressed and plastically deformed, the cylindrical part and the outer flange of the retainer guide can be formed almost simultaneously and into accurate shapes and dimensions. , The manufacturing efficiency is improved while maintaining the above-mentioned strength, and (c) Since it can be manufactured using a relatively simple molding device and molding process, costs can be reasonably reduced, and an inexpensive retainer guide can be provided.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted longitudinal sectional view of a conventional hydraulic shock absorber, Fig. 2 is a longitudinal sectional view showing an embodiment of the hydraulic shock absorber according to the present invention, and Fig. 3 is a longitudinal sectional view showing an embodiment of the hydraulic shock absorber according to the present invention. A perspective view showing an example of a retainer guide, and FIGS. 4A to 4J are diagrams shown for explaining an example of the manufacturing process of the retainer guide. DESCRIPTION OF SYMBOLS 1... Rod, 2... Piston, 5... Retainer guide, 6... Cylindrical part, 7, 18... Outer flange, 10... Wire rod, 11... Cylindrical body, 12...
Recessed portion, 14... Circular hole, 15... Hollow cylindrical body, 16
. . . Loading stand, 17 . . . Press upper mold, 17a . . . Axial rod.

Claims (1)

[Claims] 1. A method for manufacturing a retainer guide in a hydraulic shock absorber, in which a retainer guide interposed between a piston and a rod that is slidably provided in a cylinder is formed from a metal material into a cylinder having an outer flange. , a step of cutting a round rod-shaped wire made of a soft metal that can be plastically deformed in its radial direction to form a cylindrical body, cutting and edging the periphery of both ends of the cylindrical body, and forming a cylindrical column with hemmed edges at both ends. A step of pressing along the axial direction of the cylindrical body from one end side of the cylindrical body to form a recess at one end of the cylindrical body, and a process of pressing along the axial direction of the cylindrical body from the other end side of the cylindrical body with a pressing member. A cylinder is formed by punching out the center of the cylinder and forming a circular hole in the center of the cylinder by repeating the step of forming a recess at the other end of the cylinder in a cold state, The press upper mold has a hole having a circular cross section with an inner diameter slightly smaller than the outer diameter of the press mold, and a shaft rod is slidably provided coaxially with the hole and tightly fitted into the circular hole at the center of the cylinder. A shaft rod is fitted into a circular hole at the center of the cylinder placed on a press stage with one end in contact with the shaft, and the cylinder on the press stage is cold pressed by the press upper die. A method for manufacturing a retainer guide in a hydraulic shock absorber, comprising plastically deforming the outer periphery of the cylinder and forming an outer flange at one end of the cylinder.