JP2004003546A - Structure and method for fitting and fixing cylindrical member, and swaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fitting and fixing structure of a cylindrical member which materializes simple and high-strength fitting and locking without bulging or welding. <P>SOLUTION: One cylindrical member 3 of two cylindrical members to be fitted and fixed is set in an ironing device 20 together with a sleeve 11. In a manner that the sleeve 11 is supported by an inclined receiving surface 24a of the receiving die 21 and the mandrel 23 is inserted into the cylindrical member 3, the molding die 22 is lowered. While the sleeve 11 is ironed by the ironing part 26 in the molding die 22 to form the contracted diameter part 11, the lower end of the sleeve 11 is drawn by the inclined receiving surface 24a to form the drawing part 14, whereby the sleeve 11 is fitted onto the cylindrical member 3. At the same time, the material is relieved to a relief part 27 of the molding die 22 to form the expanded diameter 13 in the sleeve 11. The contracted diameter 11 is taken as a press-fitting part of the other cylindrical member. The expanded diameter 13 is taken as an engaging part of the other cylindrical member. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fitting / fixing structure and a fitting / fixing method for fitting / fixing tubular members, and a swaging apparatus used for carrying out the fitting / fixing method.
[0002]
[Prior art]
For example, as a hydraulic shock absorber, as shown in FIG. 5, an inner cylinder 2 in which a piston 1 is slidably housed is placed in a bottomed outer cylinder 3 and a piston rod 4 having one end connected to the piston 1 The other end was extended to the outside by inserting a rod guide 5 which was fitted in common to the open ends of the inner cylinder 2 and the outer cylinder 3, and the oil liquid sealed in the inner cylinder 2 was provided to the piston 1. The piston valve 6 and the base valve 7 provided at the inner bottom of the outer cylinder 3 are circulated to generate damping force in the extension stroke and the contraction stroke, and the oil liquid that enters and exits the piston rod 4 is removed from the inner cylinder 2 and the outer cylinder. 3 and a structure in which a gas and an oil liquid are compensated by a reservoir 8 filled therein.
[0003]
When this type of hydraulic shock absorber is used for a vehicle suspension, a spring seat (the other cylindrical member) 10 that receives a spring is provided at an intermediate portion of the outer cylinder (one cylindrical member) 3. Conventionally, as a structure for fitting and fixing the spring seat 10 to the outer cylinder 3, in the case of a non-strut which does not require much strength, as shown in the drawing, the middle part of the outer cylinder 3 is stepped by hydraulic bulging. An overhang 9 is formed, and a structure in which a spring seat 10 is pressed into and engaged with the overhang 9 is employed. In the case of a strut requiring strength, a special process is applied to the outer cylinder 3. A structure in which the spring seat 10 is directly welded to this without being added has been adopted.
[0004]
[Problems to be solved by the invention]
However, according to the spring seat fixing structure (the fitting and fixing structure of the tubular member) using the overhang portion 9 formed by the hydraulic bulging process, large-scale equipment is required for the bulging process, and the setup is also performed. However, there is a problem that it takes a lot of time and costs are large. It should be noted that the above-mentioned cost burden can be reduced by adopting the mechanical bulging process. However, in this case, since the plate thickness of the overhang portion 9 is reduced, the strength of the fitting and fixing portion is reduced. Become inevitable.
On the other hand, according to the spring seat fixing structure using the above welding, an oxide scale is formed on the inner surface of the outer cylinder 3 by the heat of welding, and this oxide scale enters the oil as a foreign substance (contamination) during use. was there.
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide a fitting and fixing structure and a fitting for a cylindrical member that can be fitted and fixed with high strength without relying on bulging or welding. It is another object of the present invention to provide a mating and fixing method, and also provide a swaging apparatus used for performing the fitting and fixing method.
[0005]
[Means for Solving the Problems]
A tubular member fitting and fixing structure according to the present invention for solving the above-mentioned problems is characterized in that a sleeve is fitted to the outer peripheral surface of one of the two tubular members to be fitted and fixed by swaging. On the sleeve, the reduced diameter portion and the increased diameter portion are continuously formed by the swaging process, and the reduced diameter portion of the sleeve is used as a press-fit portion of the other cylindrical member, and the increased diameter portion is connected to the other cylindrical member. Are respectively used as locking portions for restricting axial movement of the cylindrical member.
In the fitting and fixing structure of the tubular member configured as described above, the reduced-diameter portion and the enlarged-diameter portion formed on the sleeve fitted to one of the tubular members are connected to the press-fit portion and the locking portion of the other tubular member. Since it is used as a part, it is not necessary to form an overhang part in advance by bulging on one of the cylindrical members, and it is also unnecessary to weld. In addition, since the sleeve is fitted to one of the tubular members by swaging, the coupling strength of the sleeve to one of the tubular members is sufficient.
In the present fitting and fixing structure, the sleeve may be provided with minute irregularities on its inner surface in advance, whereby the coupling strength to one cylindrical member is further improved. Further, the hardness of this sleeve may be set higher than the hardness of one of the tubular members. In this case, the rigidity is sufficient even if a thin-walled sleeve is used. In particular, when the fine irregularities are provided on the inner surface, the projections of the minute irregularities bite into the outer peripheral surface of one of the tubular members, so that the bonding strength is further improved.
In the present fitting / fixing structure, the type of the two tubular members is arbitrary, but one tubular member is a tube of a hydraulic shock absorber for suspension or air suspension, and the other tubular member is a tube of suspension. It can be a spring seat for receiving a spring for use or an air piston for air suspension.
[0006]
In addition, a method for fitting and fixing a tubular member according to the present invention for solving the above-mentioned problem is a method of swaging a sleeve fitted to one of two tubular members to be fitted and fixed. In addition, the sleeve is fitted to one of the tubular members while continuously forming the reduced-diameter portion and the enlarged-diameter portion on the sleeve, and then the other tubular member is press-fitted into the reduced-diameter portion of the sleeve, and It is characterized by being engaged with the enlarged diameter portion.
In this fitting and fixing method, minute projections may be provided in advance on the inner surface of the sleeve, and the minute irregularities may be brought into close contact with the outer peripheral surface of one of the tubular members during swaging.
[0007]
Further, a swaging apparatus for solving the above-mentioned problem includes an annular receiving die for receiving one end of a sleeve fitted to a cylindrical member, and reducing the diameter of the sleeve in cooperation with the receiving die. An annular forming die fitted to the shaped member, wherein the receiving die has a receiving surface for receiving one end of the sleeve inclined in a funnel shape in a radially inward direction. A relief portion having a diameter larger than that of the swage portion is continuously provided via a taper portion at an end portion on the side opposite to the receiving die with respect to the swage portion for reducing the outer diameter.
In the swaging machine configured as described above, the receiving surface of the receiving die that receives the sleeve is inclined like a funnel, and the relief die is provided on the forming die, so that the enlarged diameter portion can be easily and reliably formed on the sleeve. Can be.
The swaging apparatus may further include a mandrel that can be inserted into the tubular member and regulates deformation of the tubular member by a predetermined amount or more during swaging.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a hydraulic shock absorber for suspension to which a tubular member fitting and fixing structure according to the present invention is applied. Since the overall structure of the hydraulic shock absorber is substantially the same as that shown in FIG. 5, the same parts as those shown in FIG. 5 are denoted by the same reference numerals, and redundant description is omitted. I decided to.
[0009]
In the present embodiment, a sleeve 11 is fitted to the outer peripheral surface of the outer cylinder (one tubular member... Tube) by swaging processing described later, and a spring seat 10 as the other tubular member is provided. The sleeve 11 is fitted and fixed to the outer cylinder 3 via the sleeve 11. The sleeve 11 includes a cylindrical reduced diameter portion 12 formed by the swaging process, a curved enlarged diameter portion 13, and a constricted portion 14 continuously. The reduced diameter portion 12 and the constricted portion 14 are provided on the outer cylinder 3. It is fixed to the outer cylinder 3 with a slight bite. On the other hand, the spring seat 10 includes a cylindrical portion 15 that can be pressed into the reduced diameter portion 12 of the sleeve 11, a step portion 16 that can be engaged with the enlarged diameter portion 13, and a collar portion 17 that receives a spring (not shown). The cylindrical portion 15 is fixed to the sleeve 11 in a state where the cylindrical portion 15 is pressed into the reduced diameter portion 12 and the step portion 16 is engaged with the enlarged diameter portion 13.
In the present embodiment, the same material as that of the outer cylinder 3 is used for the sleeve 11, and the thickness of the sleeve 11 is set to be larger than the thickness of the outer cylinder 3 as illustrated. In the present embodiment, fine irregularities 18 (FIG. 2) are formed on the inner surface of the sleeve 11 in advance, and the reduced diameter portion 12 of the sleeve 11 is closely attached to the outer peripheral surface of the outer cylinder 3 via the minute irregularities 18. I try to make it. Reference numeral 19 denotes a cover that covers an exposed portion of the piston rod 4.
[0010]
In the fitting and fixing structure of the tubular member configured as described above, the reduced diameter portion 12 and the enlarged diameter portion 13 formed on the sleeve 11 fitted to the outer cylinder 3 are used as the press-fitting portion and the locking portion of the spring seat 10. Therefore, it is not necessary to form an overhang on the outer cylinder 3 in advance by bulging or to weld the spring seat 10 to the outer cylinder 3 as in the related art, and therefore, it is advantageous in cost. In addition, contamination does not enter the oil.
Moreover, since the sleeve 11 is fitted to the outer cylinder 3 by swaging, the coupling strength of the sleeve 11 to the outer cylinder 3 is sufficient, and as a result, the coupling strength of the spring seat 10 to the outer cylinder 3 is also sufficient. Become.
[0011]
In the present embodiment, in particular, since the thickness of the sleeve 11 is set to be thicker than that of the outer cylinder 3, the rigidity of the sleeve 11 after swaging is sufficient. Even if a force is applied, the fitting and fixing structure is stably maintained. Further, since the sleeve 11 is in close contact with the outer peripheral surface of the inner cylinder 4 via the fine unevenness 18 provided on the inner surface thereof in advance, the bonding strength with the outer cylinder 3 is further improved, and the spring seat for the outer cylinder 3 is improved. The bonding strength of No. 10 is close to that of the fixing structure by welding.
The sleeve 11 may be formed from a material harder than the outer cylinder 3. In this case, sufficient rigidity can be obtained even if the thickness of the sleeve 11 is reduced, so that the weight of the sleeve 11 is reduced. Is advantageous. Further, in this case, since the projections of the minute unevenness 18 provided on the inner surface of the sleeve 11 bite into the outer peripheral surface of the outer cylinder 3, the coupling strength of the sleeve 4 to the outer cylinder 3 is further improved.
[0012]
2 and 3 show a fitting and fixing method for obtaining the fitting and fixing structure of the tubular member.
In carrying out this fitting and fixing method, first, as shown in FIG. 2, the sleeve 11 is fitted on the outer peripheral surface of the outer cylinder 3 using a dedicated swaging machine 20. The swaging device 20 includes an annular receiving die 21 surrounding the outer cylinder 3 and an annular forming die 22, and also includes a mandrel 23 that can be fitted into the outer cylinder 3. The receiving die 21 has a receiving portion 24 at an upper portion for receiving one end (lower end) of the sleeve 11 fitted to the outer cylinder 3, and a receiving surface 24 a of the receiving portion 24 is directed toward a radially inward direction. It is an inclined surface inclined in a shape. The receiving die 21 is fixedly disposed on the base 25, while the forming die 22 is supported by driving means (not shown) so as to approach and separate from the receiving die 21. The forming die 22 has a swage portion 26 for restraining the outer periphery of the sleeve 11 on the back side, and a relief portion 27 having a larger diameter than the swage portion 26 is provided at an end on the side facing the receiving die 21. Have. The swage portion 26 and the relief portion 26 are connected via a taper portion 28, and a taper portion 29 is formed on the opening end side of the forming die 22 to further release the relief portion 26 in a radially outward direction. The mandrel 23 has an outer diameter slightly smaller than the inner diameter of the outer cylinder 3 and can be positioned concentrically with the outer cylinder 3 so as to form a predetermined clearance δ with the outer cylinder 3.
[0013]
To fit the sleeve 11 on the outer peripheral surface of the outer cylinder 3, as shown in the left half of FIG. 2, the outer cylinder 3 is set by inserting the receiving die 21 and the forming die 22 in the swaging machine 20. Then, the mandrel 23 is positioned at a predetermined position in the outer cylinder 3. Then, after the sleeve 11 previously fitted to the outer cylinder 3 is seated on the receiving portion 24 of the receiving die 21, the forming die 22 is lowered by driving means (not shown). Then, as shown in the right half of FIG. 2, the substantially upper half of the sleeve 11 enters the swage portion 26 while being guided by the tapered portion 28 of the forming die 22, whereby the substantially upper half of the sleeve 11 is closed. The diameter of the outer cylinder 3 is reduced by being distorted, and a part of the outer cylinder 3 is pushed in accordance with this. Further, the lower end of the sleeve 11 placed on the receiving surface 24a of the receiving die 21 is squeezed by sliding inward in a radial direction along the funnel-shaped inclined surface of the receiving surface 24a under an axial load. A part of the outer cylinder 3 is also pushed in accordance with.
Thus, since the mandrel 23 exists inside the outer cylinder 3 with a predetermined clearance δ between the outer cylinder 3 and the outer cylinder 3, the mandrel 23 is formed by the substantially upper half of the sleeve 11 and the lower end of the sleeve 11. The pushed-in portion of the outer cylinder 3 is deformed inward by the amount of the clearance δ, and then comes into contact with the mandrel 23 so that further deformation is restricted. 14 are formed. On the other hand, the portion of the sleeve 11 located in the escape portion 27 of the forming die 22 is not restrained by the forming die 22 and the receiving die 21, so that the portion freely swells outward in the radial direction. The curved enlarged portion 13 is formed, and the fitting of the sleeve 11 to the outer cylinder 3 is completed. The diameter-reduced portion 12 of the sleeve 11 is in close contact with the outer peripheral surface of the outer cylinder 3 via the fine unevenness 18 provided on the inner surface in advance.
[0014]
According to the swaging apparatus 20, the receiving surface 24a of the receiving die 21 for receiving the sleeve 11 is inclined in a funnel shape and the relief portion 27 is provided in the forming die 22, so that the step portion 16 of the spring seat 10 is provided on the sleeve 11. The diameter-enlarged portion 13 having a curved shape for engaging with the shaft can be easily and reliably formed.
In addition, since the mandrel 23 is arranged inside the outer cylinder 3, the outer cylinder 3 is not pushed more than necessary at the time of swaging, and the shape of the reduced diameter portion 12 formed on the sleeve 11 is accurately determined. Become.
Furthermore, since the amount of deformation to the inside of the outer cylinder 3 is only required for a small clearance δ, the thickness of the overhang portion formed by the hydraulic or mechanical bulge processing described in the related art is required. A state of sufficient plate thickness (substantially equal to the plate thickness of the outer cylinder 3 before molding) can be maintained, and the strength of the fitting and fixing portion is also sufficient.
[0015]
When the fitting of the sleeve 11 to the outer cylinder 3 is completed in this way, the outer cylinder 3 is taken out of the ironing device 20, and then the spring seat 10 is connected to the outer cylinder 3 via the sleeve 11 as shown in FIG. Fit and fix. When the spring seat 10 is fitted and fixed to the outer cylinder 3, first, as shown in the left half of FIG. 3, the cylindrical portion 15 of the spring seat 10 is connected to the reduced diameter portion 12 of the sleeve 11 by using an appropriate press-fitting jig. Then, as shown in the right half of FIG. 3, the stepped portion 16 of the spring seat 10 is engaged with the enlarged diameter portion 13 of the sleeve 11 to regulate the axial movement thereof. The fitting and fixing of the spring seat 10 to 3 are completed.
[0016]
The applicable range of the fitting and fixing structure is arbitrary, and instead of the fitting and fixing between the outer cylinder 3 and the spring seat 10 of the suspension hydraulic shock absorber in the above embodiment, for example, an air suspension as shown in FIG. It is also applicable to the fitting and fixing of the outer cylinder (tube) 32 of the hydraulic shock absorber 31 and the air piston 33 in 30. Here, the air suspension 30 is connected by a rolling diaphragm 36 between an air piston 33 fitted and fixed to an outer cylinder 32 of the hydraulic shock absorber 31 and a canister 35 fixed to a piston rod 34 of the hydraulic shock absorber 31. Conventionally, the air chamber 37 is formed, and the air piston 33 is conventionally fitted and fixed to the outer cylinder 32 of the hydraulic shock absorber 31 by welding.
[0017]
In order to apply the fixed fitting structure to the air suspension 30, a sleeve 38 is fitted to the outer cylinder (one cylindrical member) 32 of the hydraulic shock absorber 31 by the same swaging as shown in FIG. The air piston (the other cylindrical member) 33 is fitted and fixed to the outer cylinder 32 via the sleeve 38. The sleeve 38 includes a cylindrical reduced diameter portion 39, a curved enlarged diameter portion 40, and a constricted portion 41 continuously. On the other hand, the air piston 34 includes a cylindrical portion 42 that can be pressed into the reduced diameter portion 39, A tapered portion 43 engageable with the enlarged diameter portion 40 and an enlarged portion 44 to which the rolling diaphragm 36 is connected are provided. To fit and fix the air piston 33 to the outer cylinder 32 of the hydraulic shock absorber 31, the cylindrical portion 42 of the air piston 33 is press-fitted into the reduced-diameter portion 39 of the sleeve 38 using an appropriate press-fitting jig. The tapered portion 43 of the air piston 33 may be engaged with the enlarged diameter portion 40 of the sleeve 38, so that the air piston 33 is firmly fitted and fixed to the outer cylinder 32 via the sleeve 38.
When applied to the air suspension 30 as described above, an elastic seal such as an O-ring is interposed between the tapered portion 43 and the enlarged diameter portion 40, and the air piston 33 is fitted and fixed to the sleeve 38. In this case, airtightness in the air chamber 37 can be maintained more reliably.
[0018]
Further, as the sleeve in the present invention, for example, a pipe agent may be cut into a thin section between predetermined thin cylinders, or a plate-shaped member formed into a substantially C-shape by roll forming.
[0019]
【The invention's effect】
As described above in detail, according to the fitting and fixing structure and the fitting and fixing method for the tubular members according to the present invention, the tubular members can be easily connected to each other via the sleeve fitted to one of the tubular members by swaging. In addition, since it can be fitted and fixed with high strength and does not need to rely on bulging, it can achieve a significant cost reduction. Further, since there is no need to rely on welding, there is no need to worry about penetration of contamination into the inside. Further, since welding is not performed, it is suitable for fitting and fixing a cylindrical member made of an aluminum-based material having poor weldability.
Further, according to the swaging apparatus according to the present invention, the receiving surface of the receiving die for receiving the sleeve is inclined in a funnel shape, and the forming die is provided with a relief portion. Can be molded into
[Brief description of the drawings]
FIG. 1 is a sectional view showing the overall structure of a suspension hydraulic shock absorber to which a tubular member fixing structure according to the present invention is applied.
FIG. 2 shows a swaging apparatus according to the present invention and a state in which swaging is performed by the apparatus. The left half thereof is a sectional view showing an initial stage, and the right half thereof is a sectional view showing a final stage.
FIG. 3 shows a method for fitting and fixing a tubular member according to the present invention, in which a left half is a sectional view showing an initial stage, and a right half is a sectional view showing a final stage.
FIG. 4 is a cross-sectional view showing the overall structure of an air suspension to which the tubular member fixing structure according to the present invention is applied.
FIG. 5 is a cross-sectional view showing the overall structure of a conventional suspension hydraulic shock absorber.
[Explanation of symbols]
3, 32 Outer cylinder of hydraulic shock absorber (one tubular member ... tube)
10 Spring seat (the other cylindrical member)
11, 38 Sleeve 12, 39 Sleeve reduced diameter portion 13, 40 Sleeve expanded diameter portion 14, 41 Sleeve squeezed portion 20 Swage processing device 21 Receiving die 22 Forming die 24a Receiving die receiving surface 26 Forming die swage portion 27 Relief portion 28 of forming die Tapered portion 30 of forming die Air suspension 33 Air piston (the other cylindrical member)

Claims (9)

A sleeve is fitted to the outer peripheral surface of one of the two tubular members to be fitted and fixed by swaging, and the sleeve is provided with a reduced diameter portion and an enlarged diameter portion by swaging. The sleeve is continuously formed, and the reduced diameter portion of the sleeve is used as a press-fit portion of the other cylindrical member, and the enlarged diameter portion is used as a locking portion that regulates the axial movement of the other cylindrical member. Fitting structure of a cylindrical member. 2. The fitting and fixing structure for a tubular member according to claim 1, wherein minute irregularities are provided on an inner surface of the sleeve in advance. 3. The fitting fixing structure for a tubular member according to claim 1, wherein the hardness of the sleeve is set to be higher than the hardness of the one cylindrical member. 4. The cylinder according to claim 1, wherein one of the cylindrical members is a tube of a suspension hydraulic shock absorber, and the other is a spring seat that receives a suspension spring. The fitting and fixing structure of the shape member. The cylindrical member according to any one of claims 1 to 3, wherein one cylindrical member is a tube of a hydraulic shock absorber for an air suspension, and the other cylindrical member is an air piston for an air suspension. Structure for fitting and fixing members. Of the two tubular members to be fitted and fixed, a swage processing is applied to a sleeve fitted to one of the tubular members, and a reduced diameter portion and an enlarged diameter portion are continuously formed on the sleeve while one of the sleeves is continuously formed. A method of fitting and fixing a tubular member, wherein the tubular member is fitted into the tubular member, and then the other tubular member is press-fitted into the reduced diameter portion of the sleeve and engaged with the enlarged diameter portion. 7. The method for fitting and fixing a tubular member according to claim 6, wherein minute projections are provided on the inner surface of the sleeve in advance, and the minute unevenness is brought into close contact with the outer peripheral surface of one of the tubular members during swaging. An annular receiving die that receives one end of the sleeve fitted to the cylindrical member, and an annular forming die that cooperates with the receiving die to reduce the diameter of the sleeve and fit the cylindrical member, The receiving die has a receiving surface that receives one end of the sleeve inclined in a funnel shape in a radially inward direction, and the forming die faces the receiving die more than a swage portion that reduces the outer diameter of the sleeve. A swaging apparatus characterized in that a relief portion having a diameter larger than that of the swage portion is connected to an end of the swage portion via a taper portion. 9. The swaging apparatus according to claim 8, further comprising a mandrel that can be inserted into the cylindrical member and restricts deformation of the cylindrical member by a predetermined amount or more during swaging.

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