JP2008189135A - Stopper - Google Patents

Abstract

It is an object of the present invention to provide a stopper that can sufficiently suppress the movement and deformation of a fork attached to a lower end of a shock absorber and does not promote welding distortion or oxidation of hydraulic oil in the shock absorber.
A bifurcated joint attached to the outer periphery of a lower end B of a shock absorber 2 and having a cylindrical fitting portion 3a fitted to the lower end B is coupled to an arm of a vehicle suspension. A main body 1a that is bent along the outer periphery of the lower end B and is welded to the outer periphery of the lower end B in the stopper 1 that abuts on the fitting portion 3a of the fork 3 and restricts the movement of the fork 3. A pair of extension portions 1b extending from both ends in the circumferential direction along the outer periphery of the lower end portion B and having an axial length shorter than that of the main body 1a. The main body 1a and the lower ends of the extension portions 1b are flush with each other. The upper end of each extension portion 1b is welded to the outer periphery of the lower end B.
[Selection] Figure 1

Description

  This invention is attached to the outer periphery of the lower end portion of the shock absorber, and has a cylindrical fitting portion that fits into the lower end portion, and abuts on a fitting portion in a fork that is connected to an arm of a vehicle suspension. And a stopper for restricting the movement of the fork.

  In general, a shock absorber for a vehicle is incorporated in a suspension and interposed between a vehicle body and an axle. Particularly, when the suspension is a double wishbone type, the shock absorber is buffered on a lower arm constituting the suspension. It is necessary to connect the lower end of the vessel.

  Depending on the configuration of the suspension, a bracket called a fork formed in a bifurcated shape may be used when connecting the lower end of the shock absorber to the lower arm because of the need to avoid the axle and tie rod. .

  The fork includes a cylindrical fitting portion that fits on the outer periphery of the lower end portion of the shock absorber, and an arm portion that extends from the fitting portion and is rotatably connected to the lower arm. By the way, in the case of such a suspension, the shock absorber is often provided with a suspension spring receiver that supports the lower end of the suspension spring that supports the vehicle body, and the weight of the vehicle body acts on the lower end portion of the shock absorber. At the same time, there is also an input such as pushing up from the lower arm through the fork while the vehicle is running (see, for example, Patent Document 1).

Therefore, as shown in FIG. 4, a stopper 14 made of a metal piece that comes into contact with the upper end of the fitting portion 13 of the fork 12 in order to restrict the movement of the fork 12 particularly upward with respect to the lower end portion 11 of the shock absorber 10. Is welded to the outer periphery of the lower end, and the stopper 14 receives the weight of the vehicle body and the push-up input from the lower arm to restrict the movement of the fork 12.
Japanese Patent Application Laid-Open No. 8-58331 (page 2, right column, lines 18 to 27, FIG. 1) JP-A-11-91325 (page 3, left column, lines 41 to 47, FIGS. 1 and 2)

  However, in the stopper 14 shown in FIG. 4, when the length of the fork 12 that contacts the fitting portion 13 is short and the push-up input from the fork 12 becomes excessive, the fork 12 moves in the swing direction relative to the shock absorber. There is a possibility that it may be pointed out that the stopper 14 itself may be deformed and peeled off from the lower end portion 11 of the shock absorber 10 or may allow the fork 12 to be deformed. is there.

  In addition, if the stopper 14 is welded over the entire circumference in a ring shape, the stopper itself is peeled off while preventing the fork 12 from being restricted or deformed in the swinging direction. This can be prevented, but this time, the weld extension (the length of the welded part) becomes longer, causing a large weld distortion in the outer cylinder and cylinder of the shock absorber 10, and the operation in the shock absorber is caused by the influence of heat during welding. There is a risk of promoting chemical reactions such as oil oxidation.

  Due to the structure of the shock absorber, welding distortion causes various adverse effects such as creating unnecessary gaps between parts and the product not meeting the design dimensions, and it is insoluble in hydraulic oil due to the chemical reaction of hydraulic oil. In an extreme case, there is a risk that inconveniences such as deterioration of slidability in the piston portion or the seal portion of the shock absorber or an influence on the damping characteristic may be caused.

  Accordingly, the present invention has been made in view of such a current situation, and an object of the present invention is to sufficiently suppress the movement and deformation of the fork attached to the lower end portion of the shock absorber and to prevent welding distortion. And a stopper that does not promote oxidation of hydraulic oil in the shock absorber.

  In order to achieve the above-described object, the problem-solving means according to the present invention includes a cylindrical fitting portion that is attached to the outer periphery of the lower end portion of the shock absorber and engages with the lower end portion. A main body that abuts on a fitting portion in a bifurcated fork connected to the arm and that regulates the movement of the fork, is bent along the outer periphery of the lower end portion, and is welded to the outer periphery of the lower end portion; A pair of extensions extending from both ends in the circumferential direction of the main body, extending along the outer periphery of the lower end and having an axial length shorter than that of the main body, and the lower ends of the main body and the respective extensions are flush with each other. As a result, the upper ends of the fitting portions of the forks were contacted, and the upper ends of the extended portions were welded to the outer periphery of the lower end portion.

  According to the stopper of the present invention, each extension portion welded to the lower end portion of the shock absorber is in contact with the upper portion of the fork fitting portion where each arm portion extends, so that it is excessive from the lower arm. Even if a simple input acts on the fitting portion via each arm portion of the fork, it is possible to prevent the fitting portion from being deformed and to effectively receive the compressive load acting on each arm portion. Therefore, the movement of the fork with respect to the shock absorber in the swing direction can be sufficiently suppressed.

  Even if an excessive compressive force is input from the fork, each extension portion of the stopper is set to have a shorter axial length than the main body, so that the extension portion is prevented from buckling. The stopper is not peeled off from the outer periphery of the lower end portion of the shock absorber, and each extension portion is maintained in contact with the fitting portion to ensure deformation of the fitting portion and shaking of the fork against the shock absorber. Movement in the moving direction can be suppressed.

  And since the stopper is not ring-shaped and does not surround the entire outer periphery of the lower end of the shock absorber, the welding extension will not become unnecessarily long. An adverse effect due to oxidation or the like can be suppressed.

  Hereinafter, the stopper of this invention is demonstrated based on figures. FIG. 1 is a side view of a shock absorber provided with a stopper according to an embodiment. FIG. 2 is a cross-sectional view of a fork attached to a shock absorber provided with a stopper in one embodiment. FIG. 3 is an AA cross-sectional view of the lower end portion of the shock absorber provided with the stopper according to the embodiment.

  As shown in FIG. 1, the stopper 1 in one embodiment is attached to the outer periphery of the lower end B of the shock absorber 2 and has a cylindrical fitting portion 3 a that fits into the lower end B. The movement of the fork 3 is restricted by contacting the fitting portion 3a of the fork 3 connected to the lower arm as the arm of the suspension of the vehicle that does not.

  As shown in FIGS. 1 to 3, the shock absorber 2 provided with the stopper 1 is configured as a known so-called double-tube shock absorber. Specifically, for example, an outer tube 2a and an outer tube are provided. A cylinder 2b disposed in 2a and a piston rod 2c that is movably inserted into the cylinder 2b via a piston (not shown), and the cylinder 2b is filled with hydraulic oil by a piston (not shown). A reservoir chamber R is formed by a gap between the side chamber and the piston side chamber R1 and the outer cylinder 2a covering the cylinder 2b. The reservoir chamber R is filled with gas and hydraulic oil.

  The shock absorber 2 applies a resistance to the flow of hydraulic fluid that exchanges the rod-side chamber and the piston-side chamber R1 when the piston rod 2c and a cylinder 2b (not shown) move in the axial direction to expand and contract. Further, the reservoir chamber R performs volume compensation so that the hydraulic oil corresponding to the volume of the piston rod 2c entering or leaving the cylinder does not become excessive or insufficient in the cylinder.

  In addition, the lower end of the outer cylinder 2a which becomes the lower end portion B of the shock absorber 2 is narrowed and reduced in diameter, and the stopper 1 is attached to the outer periphery of the lower end portion B. Further, as shown in FIG. 2, the lower end portion B is provided with a recess 2 d along a direction substantially orthogonal to the axial direction of the shock absorber 2.

  As shown in FIGS. 1 to 3, the stopper 1 includes a rectangular main body 1 a that is bent along the outer periphery of the lower end B of the shock absorber 2, and a lower end of the shock absorber 2 that extends from both circumferential ends of the main body 1 a. A pair of extension portions 1b that are set along the outer periphery of the portion B and whose axial length is shorter than the main body 1a, and a protrusion 1c that protrudes from the lower end of the main body 1a in FIG. The lower end in FIG. 1 of the extension 1b is flush.

  The stopper 1 is projection welded along the axial direction of the shock absorber 2 at two locations on both ends in the circumferential direction of the main body 1a, and the upper end of each extension portion 1b in FIG. It is fixed to the outer periphery of the lower end B of the shock absorber 2 by welding to the outer periphery of B.

  In this case, the central angle θ in the arc formed by the main body 1a of the stopper 1 and each extension 1b, that is, the arc having the end in the circumferential direction of each extension 1b as an end, is set to 180 ° or less. In this embodiment, the angle is set to about 170 °. When the stopper 1 is fixed to the lower end B of the shock absorber 2, the operation of inserting the lower end B into the arc of the stopper 1 is performed. It is unnecessary and can be welded by applying the stopper 1 from the side of the lower end B.

  On the other hand, the fork 3 has a cylindrical shape that is partially cut in the axial direction and has a split 3b, that is, a fitting portion 3a that is formed into a split cylindrical shape, and a lower end of the fitting portion 3a. And a pair of arm portions 3c that extend and are rotatably connected to a lower arm (not shown).

  The fitting portion 3a includes a bolt receiving portion 3d provided on the side portion with the split 3b interposed therebetween, and the bolt 4 is inserted therethrough, and a nut portion 3e into which the bolt 4 is screwed. The lower end B of the shock absorber 2 is inserted into 3a, and the bolt 4 is screwed into the nut portion 3e while being inserted into the bolt receiving portion 3b, so that the width of the split 3b of the fitting portion 3a is reduced. By reducing the diameter of the portion 3a, the outer periphery of the lower end B of the shock absorber 2 can be gripped.

  Further, when the fork 3 is fixed to the lower end B of the shock absorber 2, the upper end of the fitting portion 3a is brought into contact with the lower end of the stopper 1, and the projection 1c of the stopper 1 is split into the fitting portion 3a. 3b, the fitting portion 3a is positioned at a predetermined position of the lower end B of the shock absorber 2. In this state, when the bolt 4 is inserted into the bolt receiving portion 3d and screwed into the nut portion 3e, The bolt 4 enters into a recess 2d formed in the lower end B, and this functions as a retaining and detent that prevents the fork 3 from falling off the shock absorber 2 and rotating with respect to the shock absorber 2.

  The fitting portion 3a is automatically positioned in the axial direction of the shock absorber 2 by bringing the upper end of the fitting portion 3a into contact with the lower end of the stopper 1, and the fitting portion 3a is automatically activated by the presence of the protruding portion 1c. Therefore, the assembly operation of the bolt 4 is very easy.

  As described above, in a state where the fork 3 is positioned by the stopper 1 and the upward movement in FIG. 1 is restricted and is fixed to the lower end B of the shock absorber 2, the lower end of the stopper 1 is fitted to the fork 3. Since each extension portion 1b welded to the lower end portion B of the shock absorber 2 is in contact with the upper end of the joint portion 3a so as to suppress the upper portion of the fitting portion 3a where the arm portions 3c extend. Even if an excessive input from the lower arm acts on the fitting portion 3a via each arm portion 3c of the fork 3, the fitting portion 3a is deformed so that the upper end side in FIG. Can be prevented.

  That is, when a compressive force acts on the fork 3, the fork 3 has a bifurcated shape, and the line of action of the compressive force acting on each arm portion 3c is centered on the split 3b of the fitting portion 3a in FIG. Since they are displaced to the left and right, the moment that deforms the fitting portion 3a as described above acts on the fitting portion 3a, but the deformation of the fitting portion 3a due to this moment is suppressed by each extension portion 1b. It can be done.

  Furthermore, as described above, each extension 1b welded to the outer periphery of the lower end B of the shock absorber 2 is in contact with the upper portion of the fitting portion 3a where each arm 3c extends, Since the stopper 1 can effectively receive the compressive load acting on each arm portion 3c, the movement of the fork 3 in the swinging direction with respect to the shock absorber 2 can be sufficiently suppressed.

  Even if an excessive compressive force is input from the fork 3, each extension portion 1b of the stopper 1 is set to have an axial length shorter than that of the main body 1a, so that the extension portion 1b buckles. The stopper 1 is not peeled off from the outer periphery of the lower end B of the shock absorber 2, and each extension 1b is maintained in contact with the fitting portion 3a to be securely fitted. The deformation of the portion 3a and the movement of the fork 3 in the swing direction with respect to the shock absorber 2 can be suppressed.

  Since the stopper 1 is not ring-shaped and does not surround the entire outer periphery of the lower end B of the shock absorber 2, when the stopper 1 is attached to the lower end B of the shock absorber 2, it extends over the entire periphery of the lower end B. There is no need to weld. That is, since the welding extension when attaching the stopper 1 to the lower end B of the shock absorber 2 does not become unnecessarily long, a large welding distortion is caused in the outer cylinder 2a and the cylinder 2b of the shock absorber 2. There is no risk of unnecessarily promoting a chemical reaction such as oxidation of the hydraulic oil in the shock absorber 2. Therefore, according to the stopper 1, it is possible to suppress the shock absorber 2 from being adversely affected by welding distortion, hydraulic oil oxidation, and the like.

  Furthermore, although the central angle θ in the arc formed by the main body 1a of the stopper 1 and each extension portion 1b may be set to 180 ° or more, as in the present embodiment, the main body 1a of the stopper 1 and each extension portion. When the center angle θ in the arc formed by 1b is set to 180 ° or less, as described above, the work for welding the stopper 1 to the lower end B of the shock absorber 2 is simplified, and the stopper Since the deformation and displacement of the fork 3 can be prevented without unnecessarily increasing the size of 1, the manufacturing cost of the shock absorber 2 including the stopper 1 is reduced, and the practicality is improved.

  In addition, the welding extension in each said extension part 1b acts on the fitting part 3a with the load which acts on the lower end part B of the buffer 2 which should be supported with the stopper 1, ie, the compression force which acts on the fork 3, and the said compression force. What is necessary is just to obtain | require and determine the shear strength in the welding part of the extension part 1b which will be requested | required from a moment and the fixed shear strength by the projection welding of the main body 1a.

  Therefore, it is not necessary to weld the extended portion 1b to the lower end portion B over the entire length in the circumferential direction, and it may be welded so as to ensure the required weld extension as described above.

  Further, the central angle θ of the arc formed by the main body 1a of the stopper 1 and each extension portion 1b sufficiently suppresses deformation of the fitting portion 3a due to the moment acting on the fitting portion 3a due to the compressive force acting on the fork 3. As in this embodiment, the central angle θ should be close to 170 °, and the stopper 1 that achieves the above-described effects can be realized efficiently without wasting material costs. Can do.

  In the above description, the fitting portion 3a of the fork 3 is described as having a split 3b. However, even when the fitting portion is formed in a cylindrical shape without a split. The movement of the fork 3 attached to the lower end B of the shock absorber 2 can be sufficiently suppressed, and the effect of not promoting the welding distortion and the oxidation of the hydraulic oil in the shock absorber 2 is not lost.

  Further, in the case of the present embodiment, the lower end of the outer cylinder 2a of the shock absorber 2 is reduced in diameter to form the lower end B, but the lower end B is not particularly reduced in diameter, but the above-described stopper 1 is provided. Naturally, the operational effects are not lost. Furthermore, although the shock absorber 2 is a double cylinder type, it may be a single cylinder type shock absorber.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

It is a side view of the shock absorber provided with the stopper in one embodiment. It is sectional drawing of the fork attached to the buffer provided with the stopper in one Embodiment. It is AA sectional drawing of the lower end part of the buffer provided with the stopper in one embodiment. It is a side view of the buffer provided with the conventional stopper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stopper 1a Main body 1b Extension part 1c Projection part 2 Shock absorber 2a Outer cylinder 2b Cylinder 2c Piston rod 2d Depression 3 Fork 3a Fitting part 3b Split part 3c Arm part 3d Bolt receiving part 3e Nut part 4 Bolt B Lower end R Reservoir chamber R1 Piston side chamber

Claims (3)

Attached to the outer periphery of the lower end portion of the shock absorber, has a cylindrical fitting portion that fits to the lower end portion, and abuts on a fitting portion of a bifurcated fork that is connected to a suspension arm of a vehicle. A fork that restricts movement of the fork, a main body that is bent along the outer periphery of the lower end and is welded to the outer periphery of the lower end, extends from both ends in the circumferential direction of the main body, and extends along the outer periphery of the lower end. A pair of extension portions whose axial length is set to be shorter than that of the main body, and the lower ends of the main body and the respective extension portions are flush with each other and are brought into contact with the upper ends of the fitting portions of the forks and the upper ends of the respective extension portions. A stopper which is welded to the outer periphery of the lower end portion. The stopper according to claim 1, wherein a central angle in an arc formed by the main body and each extension portion is set to 180 ° or less. The fitting part of the fork is set to be a cut-off cylinder, and has a projection that enters the fitting part of the fork at the lower end of the main body. The main body excluding this projection and the lower end of each extension part are fitted. The stopper according to claim 1 or 2, wherein the stopper is brought into contact with the joint.

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