JP3050995B2 - Method for manufacturing tubular member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a cylindrical member having a large diameter at both ends used in a bush type liquid filled type vibration damping device.

[0002]

2. Description of the Related Art A bush type liquid-filled vibration isolator having an inner cylinder and an outer cylinder uses a steel intermediate cylinder to which an elastic body is vulcanized and bonded.

Such intermediate cylinders include an intermediate cylinder 100 as shown in FIG. 11 and an intermediate cylinder 14 as shown in FIG.

As shown in FIG. 11, an intermediate cylinder 100 has a large diameter portion 102 having a circular cross section at both ends, and a small diameter portion 104 having a circular cross section at an intermediate portion.

As shown in FIG. 10, the intermediate cylinder 14 has a large diameter portion 14A having a circular cross section at both ends, and the intermediate portion has a non-circular irregular cross section.

[0006]

The intermediate cylinder 100 having a circular cross section as shown in FIG. 11 is formed by spinning forming a steel pipe to increase or decrease its diameter. However, for steel pipes, materials are selected mainly for piping, etc., and plastic processing for diameter reduction and expansion is not the main purpose, so it is difficult to increase the elongation of the material, and when processing with a large diameter difference There is a problem that dimensional accuracy (particularly, variation in thickness) is deteriorated and cracks and wrinkles are generated, which may be restricted in design and manufacturing.

Further, since the intermediate cylinder 14 having a complicated shape having a non-circular cross section as shown in FIG. 10 cannot be subjected to spinning forming, it is conventionally divided into half as shown in FIG. Pressed product 10 with step
6 are integrated with each other by welding 108. However, in many cases, thermal deformation occurs during welding, and the subsequent correction work becomes complicated.
It takes a lot of trouble to integrate the coaxially.

An object of the present invention is to provide a method of manufacturing a cylindrical member capable of efficiently manufacturing a cylindrical member having good dimensional accuracy in consideration of the above fact.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a method of manufacturing a cylindrical member whose both ends are enlarged, wherein a blank is pressed to form one of a cylindrical portion and an opening of the cylindrical portion. A first flange portion provided on the other of the cylindrical portions and extending radially outward; and a cylindrical portion provided on an outer peripheral edge of the first flange portion along an axis of the cylindrical portion. A first step of forming a molded article having a first large-diameter cylindrical part extending in a direction away from the shaped part, a second step of removing the bottom of the molded article, and the bottom being removed. The molded product is pressed to expand the end of the cylindrical portion on the side opposite to the first flange portion side, and a second flange portion extending radially outward and a second flange portion are formed. A second large portion provided on an outer peripheral edge and extending in a direction away from the cylindrical portion along an axis of the cylindrical portion; A third step of forming a tubular portion,
It is characterized by having.

[0010]

According to the method for manufacturing a tubular member of the present invention, the blank is pressed in the first step to form a tubular portion, a bottom portion for closing one of the openings of the tubular portion, and a blank for the other portion of the tubular portion. A first flange portion provided and extending radially outward, and a first large-diameter cylindrical portion provided on an outer peripheral edge of the first flange portion and extending in a direction away from the cylindrical portion along an axis of the cylindrical portion. And a molded article having:

In a second step, the bottom of the molded article is removed. In the third step, the molded product from which the bottom has been removed is subjected to press working to increase the diameter of the end of the cylindrical portion on the side opposite to the first flange portion side, and to expand the second flange portion radially outward. ,
A second large-diameter cylindrical portion provided on the outer peripheral edge of the second flange portion and extending in a direction away from the cylindrical portion along the axis of the cylindrical portion.

Through these first to third steps, the blank is provided with a first flange portion and a second flange portion extending radially outward at both ends of the tubular portion, and the first flange portion and the second flange portion. A cylindrical member provided on the outer peripheral edge of the second flange portion and having a first large-diameter cylindrical portion and a second large-diameter cylindrical portion extending in a direction away from the cylindrical portion along the axis of the cylindrical portion. Molded into

[0013]

【Example】

[First Embodiment] A first embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 2, the vibration isolator 10 is provided with an outer cylinder 12, and an intermediate cylinder 14 is inserted into the outer cylinder 12.

As shown in FIG. 3, the intermediate cylinder 14 is formed of a metal plate (a steel plate in this embodiment) in a tubular shape. Both ends in the axial direction (direction of arrow A) of the intermediate cylinder 14 are large-diameter portions 14A having a circular cross section, and the intermediate portion in the axial direction is a small-diameter portion 14A.
B. The small diameter portion 14B is formed in a cylindrical shape, and has a flat portion 14C partially parallel to the axis. The large diameter portion 14A and the small diameter portion 14B are integrally connected by a flange portion 14D extending in a radial direction.

The small-diameter portion 14B has a flat portion 1 sandwiching the axis.
A rectangular notch 16 is formed on the side opposite to the 4C side.

As shown in FIGS. 1 and 2, an inner cylinder 18 is provided inside the intermediate cylinder 14, and a main body rubber as an elastic body is provided between the inner cylinder 18 and the intermediate cylinder 14. Twenty have been bridged. The main rubber 20 is respectively vulcanized and bonded to the outer peripheral surface of the inner cylinder 18 and the inner peripheral surface of the intermediate cylinder 14, and a part of the thin main rubber 20 is applied to the outer peripheral surface of the intermediate cylinder 14. Sulfur adhesive. In addition, a semi-arc-shaped rigid plate 22 circling the inner cylinder 18 is embedded in the main rubber 20 to adjust the rigidity of the main rubber 20.

The main rubber 20 has a notch 16 of the intermediate cylinder 14.
The recess 20A is formed at a position corresponding to
A gap portion 24 penetrating in the axial direction is formed between the inner cylinder 18 and the flat portion 14C.

As shown in FIG. 2, the large diameter portion 1 of the intermediate cylinder 14
4A, the outer peripheral surface is in close contact with the inner peripheral surface of the outer cylinder 12.

As shown in FIG. 1, the large diameter portion 1 of the intermediate cylinder 14
The restricted passage constituting member 26 is fitted between 4A. The restriction passage constituting member 26 is formed in a substantially semi-circular shape when viewed from the axial direction of the outer cylinder 12. As shown in FIG. 2, the side surfaces on both sides in the axial direction are connected to the flange portion 14 </ b> D of the intermediate cylinder 14 through the thin portion of the main rubber 20 through the thin portion of the main rubber 20. Each is in close contact.

The concave portion 20A of the main rubber 20 is closed by a restricting passage constituting member 26 to form a pressure receiving liquid chamber 28.

As shown in FIG. 1, the plane portion 1 of the intermediate cylinder 14
4C, a space 30 surrounded by the outer cylinder 12, the intermediate cylinder 14, and the restriction passage constituting member 26 has a diaphragm 3
2 are provided.

The diaphragm 32 is formed in a convex shape toward the inner cylinder 18, and a support fitting 34 is fixed to the outer peripheral edge. The outer peripheral edge of the diaphragm 32 is in close contact with the inner peripheral surface of the outer cylinder 12, and the space 30 is divided by the diaphragm 32 into a sub-liquid chamber 36 on the radially inner side and an air chamber 40 on the opposite side. Note that the air chamber 40 may be communicated with outside air as needed.

As shown in FIG.
A U-shaped narrow groove 42 is formed on the outer periphery of the. As shown in FIG. 1, one end (not shown) of the narrow groove 42 is connected to the auxiliary liquid chamber 36, and the other end is connected to the pressure receiving liquid chamber 2 through an opening 42A.
8 and is surrounded by the outer cylinder 12 and
Is composed. The pressure receiving liquid chamber 28, the auxiliary liquid chamber 36, and the restriction passage 46 are filled with a liquid such as ethylene glycol.

A stopper fitting 48 having a hat-shaped cross section is provided inside the pressure receiving liquid chamber 28. The stopper fitting 48 has both ends 48A sandwiched between the restricted passage forming member and the small diameter portion 14B of the intermediate cylinder 14,
The top plate 48B is arranged at a predetermined distance from the recess 20A.

Next, the manufacturing process of the intermediate cylinder 14 will be described with reference to FIGS. As shown in FIG. 5, in the first step A, a blank (steel plate in this embodiment) 50 is deep drawn using a first press die 60 described later. The blank 50 is cut or punched in a predetermined size in advance.

As shown in FIG. 6, the first press die 60
Is composed of a punch 62, a die 64, and a wrinkle holder 66. The punch 62 and the wrinkle holder 66 are attached to a slide side of a press (not shown).
Reference numeral 4 is also attached to a table side of a press (not shown). The punch 62 has a columnar shape partially having a flat portion 62 </ b> A, and the die 64 has a modified hole 70 corresponding to the cross section of the punch 62.

The blank is sandwiched between the wrinkle retainer 66 and the die 64, and then the punch 62 is
4A, the sheet is deep drawn, and the first molded article 70 is obtained.
The primary molded product 70 is formed in a cup shape with a flange, and has a deformed cylindrical portion 70A (a portion to be a small diameter portion 14B of the intermediate cylinder 14 shown in FIG. 3), a bottom portion 70B, and a flange 70C.
(A part to be the flange portion 14D of the intermediate cylinder 14 shown in FIG. 3).

As shown in FIG. 5, in the next step B, the first step
The next molded product 70 is redrawn by a second press die 72 described later to be a second molded product 82.

As shown in FIG. 7, the second press mold 72
Is composed of a punch 74 and a die 76.
Is mounted on the slide side of a press (not shown), and the die 76 is mounted on the table side of the press (not shown). The punch 74 has a smaller diameter and a longer axial length than the cylindrical portion of the punch 62 of the first press die 60,
A large-diameter cylindrical portion 78 is provided coaxially on the base. On the other hand, a deformed hole 80 corresponding to the punch 74 is formed in the die 76.

As shown in FIG. 5, the secondary molded product 82 formed by the second press mold 72 is
It has a deformed cylindrical portion 82A and a bottom portion 82B whose diameters are smaller than 0, and a large diameter portion 82D on the outer peripheral edge of the flange 82C.
(A part to be the large diameter part 14A of the intermediate cylinder 14 shown in FIG. 3).

In the step C, the second molded product 82 is further redrawn by a third press die (not shown) to form a third molded product 84. The third press die is composed of a punch and a die (both not shown), as in the second press die 72, and is different from the second press die 72 in the shape of the cylindrical portion of the punch and the die. The hole (not shown) is reduced in diameter. Therefore, the third molded product 84 is the second molded product 8
It has a deformed cylindrical portion whose diameter is smaller than 2.

In the step D, the corners of the tertiary molded product 84 are formed by a press die (not shown) at an acute angle, and the ends are corrected to form the large diameter portion 14A and the flange portion 14D.

In step E, the bottom 84 of the third molded product 84
B is punched by a press die (not shown).

In step F, the end of the large diameter portion of the third molded product 84 is trimmed at right angles to the axis.

In the next step G, the tertiary molded product 84 has a predetermined mold (not shown, but the punch has a convex portion forming the large diameter portion 14A and the flange portion 14D, and the die has a predetermined shape. A concave portion forming the large-diameter portion 14A and the flange portion 14D is provided.)
Are enlarged in diameter to form a large diameter portion 14A and a flange portion 14D.
Is formed.

In the next step H, a part of the small-diameter portion 14B is punched out with a predetermined mold (not shown), and a notch 16 is formed.

In the next step I, the end of the large diameter portion 14A formed in the step G is trimmed at right angles to the axis with a predetermined mold (not shown).

Through the above steps A to I, the intermediate cylinder 14 is formed. Next, the operation of the present embodiment will be described.

As described above, the intermediate cylinder 14 of this embodiment is
Because a metal plate (steel plate) is formed by a press die,
The dimensional accuracy is high, and there is no danger of dimensional variations between products. Furthermore, there are many types of metal plates suitable for press forming, and the plate thickness is abundant, so that a wide range of materials can be selected. Therefore, as compared with the conventional method of plastically processing a steel pipe to obtain an intermediate cylinder, the degree of freedom in design is large, and there is little possibility that excessive force will be caused during molding.

The vibration isolator 10 is, for example,
The inner cylinder 18 is connected to an automobile engine by bolts (not shown), and the outer cylinder 12 is connected to the vehicle body via a bracket (not shown).

When the vibration of the engine is input to the vibration isolator 10, the vibration of the engine is supported by the vehicle body through the inner cylinder 18, the main rubber 20 and the outer cylinder 12, and is generated by the resistance due to the internal friction of the main rubber 20. Vibration is absorbed. Further, in the vibration isolator 10, the pressure-receiving liquid chamber 28 expands and contracts due to the vibration input, and the liquid moves between the pressure-receiving liquid chamber 28 and the sub-liquid chamber 36, and resonates in the restriction passage 46. Can generate force.

Further, since the intermediate cylinder 14 is formed with good dimensional accuracy, it has excellent adhesion to the outer cylinder 12.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS.

The anti-vibration device 10 of the present embodiment is a modification of the anti-vibration device 10 of the first embodiment, and the same components are denoted by the same reference numerals and description thereof will be omitted.

As shown in FIGS. 8 and 9, in the vibration isolator 10 of this embodiment, a part of the thin rubber 90 which is vulcanized and bonded to the inner peripheral surface of the outer cylinder 12 is moved from the inner peripheral surface to the inner cylinder. A diaphragm 92 is formed so as to protrude toward the 18th side. The outer cylinder 1
2, a hole 94 is formed in a portion corresponding to the diaphragm 92.

A U-shaped stopper fitting 96 is fixed to the inner cylinder 18 on the side of the pressure receiving liquid chamber 28, and the entire stopper fitting 96 is covered with the main rubber 20.

A wide groove 98 extending in the circumferential direction is formed in the restriction passage constituting member 26 of the present embodiment, and one end is connected to the auxiliary liquid chamber 36 and the other end is connected to the pressure receiving liquid chamber 2 through the opening 98A.
8. The wide groove 98 is surrounded by the outer cylinder 12 and forms the restriction passage 46.

As shown in FIG. 10, the intermediate cylinder 1 of this embodiment
4 has a different shape from the intermediate cylinder 14 of the first embodiment,
The portion facing the auxiliary liquid chamber 36 is an inclined portion 14E having a substantially U-shaped cross section. In the large-diameter portion 14A of the intermediate cylinder 14 of the present embodiment, the notch 16 side is wide in the axial direction.

The intermediate cylinder 14 of this embodiment is also formed through the same steps as those for manufacturing the intermediate cylinder 14 of the first embodiment.
Therefore, the intermediate cylinder 14 of the present embodiment has high dimensional accuracy, similarly to the intermediate cylinder 14 of the first embodiment.

Although not shown, the press die for forming the intermediate cylinder 14 of this embodiment has a shape corresponding to the shape of the intermediate cylinder 14 of this embodiment.

[0052]

According to the method of manufacturing a tubular member of the present invention, a blank is pressed to form a tubular portion, a bottom portion for closing one of the openings of the tubular portion, and a blank portion provided on the other of the tubular portion. A first flange portion extending radially outward, and a first large-diameter cylinder provided on an outer peripheral edge of the first flange portion and extending in a direction away from the cylindrical portion along an axis of the cylindrical portion. A first step of forming a molded article having a shape, a second step of removing the bottom of the molded article, and a second step of pressing the molded article from which the bottom has been removed by pressing the molded article. A second flange portion that expands in diameter at an end opposite to the first flange portion side and expands radially outward, and along an axis of the cylindrical portion provided on an outer peripheral edge of the second flange portion. And a second large-diameter cylindrical portion extending in a direction away from the cylindrical portion. It is therefore, has an excellent effect that it is possible to efficiently produce a good tubular member dimensional accuracy.

[Brief description of the drawings]

FIG. 1 is a sectional view perpendicular to an axis of a vibration isolator according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along an axis of the vibration isolator according to the first embodiment of the present invention.

FIG. 3 is a perspective view of an intermediate cylinder according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a restriction passage constituting member according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing a manufacturing process of the intermediate cylinder according to the first embodiment of the present invention.

FIG. 6 is a sectional view showing a first molding die according to the first embodiment of the present invention.

FIG. 7 is a sectional view showing a second mold according to the first embodiment of the present invention.

FIG. 8 is a cross-sectional view perpendicular to an axis of a vibration isolator according to a second embodiment of the present invention.

FIG. 9 is a sectional view taken along an axis of a vibration isolator according to a second embodiment of the present invention.

FIG. 10 is a perspective view of an intermediate cylinder according to a second embodiment of the present invention.

FIG. 11 is a perspective view of a conventional intermediate cylinder.

FIG. 12 is a perspective view of a conventional intermediate cylinder formed by welding.

[Explanation of symbols]

14 Intermediate cylinder (cylindrical member) 14A Large diameter section (first large diameter cylindrical section, second large diameter cylindrical section) 14D flange section (first flange section, second flange section) 50 blank 82 Secondary molded product (molded product) 82A Deformed cylindrical part (cylindrical part) 84B Bottom part

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Claims (1)

(57) [Claims] 1. A method for manufacturing a cylindrical member having both ends enlarged in diameter, comprising: pressing a blank to form a cylindrical portion; a bottom portion for closing one of openings of the cylindrical portion; A first flange portion provided on the other of the shape portions and extending radially outward;
A first large-diameter cylindrical portion provided on the outer peripheral edge of the flange portion and extending in a direction away from the cylindrical portion along the axis of the cylindrical portion, a first step of forming a molded product; A second step of removing the bottom of the molded article; and press-forming the molded article from which the bottom has been removed to increase the diameter of the end of the cylindrical portion opposite to the first flange side. A second flange portion extending radially outward, and a second large-diameter cylinder provided on an outer peripheral edge of the second flange portion and extending in a direction away from the cylindrical portion along an axis of the cylindrical portion. And a third step of forming a cylindrical portion.