JP2021167626A - Buffer - Google Patents

Abstract

To provide a buffer capable of fitting a bracket to an outer shell, and capable of achieving high roundness of a bracket attachment portion.SOLUTION: A buffer D of this invention includes: a cylindrical outer shell 1 having a bracket attachment portion 1a to which a bracket 3 connected with a knuckle supporting a wheel of a vehicle is fitted on a lower end side outer periphery; and a lower cap 2 welded at a position shifting to an upper end side from a lower end 1b of the outer shell 1 in an inner periphery of the outer shell 1 so as to close an opening on the lower end side of the outer shell 1. A gap G storing a weld bead B generated at a joint portion between the outer shell 1 and the lower cap 2 is formed in an inner side of the lower end 1b of the outer shell 1.SELECTED DRAWING: Figure 2

Description

The present invention relates to a shock absorber.

The shock absorber includes an outer shell and a piston rod that is movably inserted into the outer shell. For example, the shock absorber is used by being incorporated in a suspension in a vehicle, and the piston rod moves axially with respect to the outer shell. Sometimes it exerts a damping force to suppress the vibration of the car body and wheels. The shock absorber incorporated in the suspension in this way is provided between the vehicle body and the wheels by, for example, a mount for connecting the piston rod to the vehicle body and a bracket for connecting the outer shell to the knuckle holding the wheels. Be disguised.

When the shock absorber is used as a strut, the shock absorber may be held by a bracket called a knuckle carrier that extends from the knuckle to which the hub that rotatably supports the wheel is mounted. Further, when the suspension is a double wishbone, the shock absorber may be connected to a lower arm that swingably connects the knuckle to the vehicle body via a bifurcated fork bracket.

In either case, if the shock absorber is incorporated into the suspension that suspends the drive wheels, the bracket should place the bottom edge of the shock absorber above the drive shaft to avoid interference between the bottom edge of the shock absorber and the drive shaft that drives the drive wheels. Need to be placed in.

Therefore, when the bracket A is a knuckle carrier, as shown in FIG. 4, the bracket A has an arm a1 extending upward from the knuckle N and a lower end of the outer shell T of the shock absorber provided at the tip of the arm a1. It is configured to include a tubular grip portion a2 for gripping the above.

Therefore, in the shock absorber to which such a bracket A is mounted, a bracket mounting portion t1 to which the bracket A is mounted is formed below the stopper S mounted on the lower outer periphery of the outer shell T (for example,). See Patent Document 1).

In such a conventional shock absorber, a disk-shaped lid member called a lower cap C, which closes the lower end of the outer shell T, is attached to the lower end of the outer shell T by welding. Specifically, the lower cap C is welded to a small diameter portion t2 formed by narrowing the lower end diameter of the outer shell T by one step, and by providing the small diameter portion t2 in this way, the lower end of the outer shell T and the lower end are welded. The weld bead generated on the outer periphery of the cap C does not interfere with the insertion from the lower end side of the bracket A. Therefore, the bracket mounting portion t1 is formed at the lower end side of the outer shell T where the diameter does not change between the small diameter portion t2 and the stopper S.

Japanese Unexamined Patent Publication No. 2008-82492

In the shock absorber configured in this way, if play occurs between the grip portion a2 of the bracket A and the bracket mounting portion t1 of the outer shell T to which the grip portion a2 is mounted, the position of the wheel with respect to the vehicle body shifts. Therefore, a high degree of roundness is required for the bracket mounting portion t1.

However, in the conventional shock absorber, as described above, the outer shell T is provided so that the welding bead generated when the lower cap C is welded to the outer shell T when the bracket A is fitted to the outer shell T does not get in the way. It is necessary to draw the lower end to reduce the diameter, and if the drawing process is applied to the outer shell T, the bracket mounting portion t1 may be distorted.

As described above, in the conventional shock absorber, not only the bracket A can be fitted to the bracket mounting portion t1 at the lower end of the outer shell T, but also the high roundness of the bracket mounting portion t1 is realized, which is a trade-off. There was a problem that the two requirements related to each other had to be compatible.

Therefore, an object of the present invention is to provide a shock absorber capable of fitting the bracket to the outer shell and realizing a high roundness of the bracket mounting portion.

In order to solve the above-mentioned problems, the shock absorber of the present invention has an outer shell having a bracket mounting portion in which a bracket connected to a knuckle that supports the wheels of the vehicle is fitted on the outer periphery on the lower end side in a tubular shape. , With a lower cap that is the inner circumference of the outer shell and is welded at a position shifted from the lower end to the upper end side of the outer shell to close the opening on the lower end side of the outer shell, and the outer shell is provided inside the lower end of the outer shell. A gap is formed in the joint with the lower cap to store the weld bead. According to the shock absorber configured in this way, the weld bead generated at the joint between the outer shell and the lower cap is accumulated in the gap and does not protrude to the outer peripheral side of the outer shell, so that the lower end of the outer shell is not reduced in diameter. The outer shell can be inserted into the bracket.

The lower cap in the shock absorber may have a disc-shaped tapered portion whose outer circumference is inclined toward the upper end side of the outer shell. Further, the lower cap in the shock absorber may have a curved surface portion which is disk-shaped and whose outer circumference is curved toward the upper end side of the outer shell. According to the shock absorber configured in this way, the overall length of the shock absorber can be shortened and the weight can be reduced.

Further, the shock absorber may be configured so that the entire lower cap is housed in the outer shell, and according to the shock absorber configured in this way, when the shock absorber is mounted on the vehicle via the bracket. Interference between the lower cap and the drive shaft can be effectively avoided.

Further, according to the shock absorber configured so that the lower cap is welded to the outer shell at a position separated from the bracket mounting portion toward the lower end side, the bracket mounting portion is not distorted by welding the lower cap, and the bracket. It does not adversely affect the roundness of the mounting part.

The bracket may be a knuckle carrier integrated with the knuckle.

According to the shock absorber of the present invention, the bracket can be fitted to the outer shell and the bracket mounting portion can be highly rounded.

It is a side view of the shock absorber in one embodiment. It is an enlarged sectional view of the lower end part of the shock absorber in one Embodiment. It is an enlarged sectional view of the lower end part of the shock absorber in one modification of one Embodiment. It is a side view of the conventional shock absorber.

Hereinafter, the present invention will be described based on the embodiments shown in the figure. As shown in FIGS. 1 and 2, the shock absorber D is an outer shell 1 having a tubular shape and having a bracket mounting portion 1a to which the bracket 3 is fitted on the outer periphery on the lower end side, and an inner circumference of the outer shell 1. A vehicle that is welded at a position deviated from the lower end 1b of the outer shell 1 to the upper end side and is provided with a lower cap 2 that closes the opening on the lower end side of the outer shell 1 and is not shown by using the bracket 3. Connected to a knuckle that supports the wheels.

The shock absorber D is movably inserted into the tubular outer shell 1, the lower cap 2 that closes the opening of the lower end 1b of the outer shell 1, the cylinder 4 inserted into the outer shell 1, and the cylinder. It includes a piston rod 5 and a piston 6 which is connected to the piston rod 5 and inserted into the cylinder 4 to divide the inside of the cylinder 4 into an extension side chamber R1 and a compression side chamber R2.

The extension side chamber R1 and the compression side chamber R2 are filled with hydraulic oil. Further, the liquid used for the shock absorber D may be a liquid such as water or an aqueous solution in addition to the hydraulic oil. The annular gap between the outer shell 1 and the cylinder 4 is used as a reservoir 8 and is filled with hydraulic oil and gas as a liquid.

The piston 6 includes an extension side port 6a and a compression side port 6b that communicate the extension side chamber R1 and the compression side chamber R2, and the compression side leaf valve Vc and the extension side leaf valve Ve are provided on the upper surface and the lower surface of the piston 6, respectively. Stacked. The extension side leaf valve Ve is laminated on the lower surface of the piston 6 to close the lower end of the extension side port 6a, and is bent by the pressure of the extension side chamber R1 to open the extension side port 6a from the extension side chamber R1. It resists the flow of liquid towards the compression side chamber R2. The leaf valve Vc on the compression side is laminated on the upper surface of the piston 6 to close the upper end of the compression side port 6b, and by bending due to the pressure of the compression side chamber R2, the compression side port 6b is opened and the compression side chamber R2 to the extension chamber R1 Resists the flow of liquid towards.

Although not shown, a rod guide that is in sliding contact with the outer periphery of the piston rod 5 is attached to the upper end of the outer shell 1. Further, as shown in FIG. 2, a valve case 7 is fitted to the lower end of the cylinder 4, and the cylinder 4 is formed by a lower cap 2 welded to the inner circumference on the lower end 1b side of the outer shell 1 and a rod guide. And the valve case 7 are sandwiched and fixed to the outer shell 1. The outer shell 1 has a large inner diameter portion 1c formed by forming the inner diameter of the lower end portion to a larger diameter than the upper side thereof and a step portion formed on the inner circumference by providing the large inner diameter portion 1c. It has 1d. The disk-shaped lower cap 2 is joined to the inner circumference of the outer shell 1 by welding while being inserted into the outer shell 1 until it comes into contact with the step portion 1d. As shown in FIG. 1, the bracket mounting portion 1a of the outer shell 1 is a portion where the bracket 3 is fitted, that is, a range of the bracket 3 of the outer shell 1 facing from the upper end to the lower end in FIG. ing. Further, the outer diameter of the outer circumference from the bracket mounting portion 1a to the lower end 1b of the outer shell 1 does not change constantly, and the outer peripheral shape from the bracket mounting portion 1a to the lower end 1b of the outer shell 1 becomes a straight cylindrical shape. There is. The step portion 1d is provided at a position separated from the position where the bracket mounting portion 1a of the outer shell 1 is provided toward the lower end 1b side in the axial direction so that the bracket mounting portion 1a is not distorted by welding the lower cap 2. Has been done.

Further, the valve case 7 includes a suction port 7a and a discharge port 7b that communicate the reservoir 8 and the compression side chamber R2, and an annular leg portion 7c in which a notch 7d is formed on the outer periphery of the lower end. The upper end of the suction port 7a is closed by an annular check valve 9. When the pressure of the reservoir 8 becomes higher than the pressure of the compression side chamber R2, the check valve 9 bends and opens the suction port 7a to allow the liquid to flow from the reservoir 8 to the compression side chamber R2, but the check valve 9 allows the liquid to flow from the compression side chamber R2 to the reservoir 8. Block the flow of liquid towards. The lower end of the discharge port 7b is blocked by the annular base valve 10. The base valve 10 bends due to the pressure of the compression side chamber R2 to open the discharge port 7b and gives resistance to the flow of liquid from the compression side chamber R2 to the reservoir 8.

The shock absorber D is a leaf on the extension side with respect to a flow of liquid moving from the extension side chamber R1 compressed by the piston 6 to the compression side chamber R2 expanding when the piston rod 5 moves upward with respect to the outer shell 1. The valve Ve creates a damping force that provides resistance and hinders elongation. When the shock absorber D is extended, the check valve 9 opens and hydraulic oil is supplied from the reservoir 8 to the compression side chamber R2 via the suction port 7a to compensate for the volume of the piston rod 5 exiting the cylinder 4. On the other hand, the shock absorber D is on the compression side with respect to the flow of the liquid moving from the compression side chamber R2 compressed by the piston 6 to the extension side chamber R1 expanding when the piston rod 5 moves downward with respect to the outer shell 1. The leaf valve Vc provides resistance. Further, when the shock absorber D contracts, the base valve 10 opens and the hydraulic oil is discharged from the compression side chamber R2 to the reservoir 8 via the discharge port 7b, and the volume of the piston rod 5 entering the cylinder 4 is compensated. Therefore, when the shock absorber D contracts, the leaf valve Vc on the compression side and the base valve 10 generate a damping force that hinders the contraction. The pressure-side leaf valve Vc laminated on the piston 6 may be changed to a check valve, in which case the compression-side damping force is generated only by the base valve 10.

Further, the above-mentioned shock absorber D is a so-called double-cylinder type shock absorber, but the piston is slidably contacted with the inner circumference of the outer shell 1 and the inside of the outer shell 1 is divided into an extension side chamber and a compression side chamber by a piston. It may be a so-called single-cylinder type shock absorber.

As shown in FIGS. 1 and 2, stoppers 11 for positioning the bracket 3 in the axial direction and the circumferential direction with respect to the outer shell 1 are attached to the outer periphery of the lower end of the outer shell 1 by welding. A bracket mounting portion 1a on which the bracket 3 is mounted is provided on the outer circumference of the outer shell 1 and below the stopper 11. The stopper 11 is a rectangular mounting piece 11a that is curved along the outer circumference of the outer shell 1 and is projection-welded to the outer circumference of the outer shell 1, and is inclined so as to be separated from the outer shell 1 diagonally downward from the lower end of the mounting piece 11a. It is provided with a guide piece 11b that protrudes. The guide piece 11b is used for positioning and rotation regulation of the bracket 3, which will be described later. The stopper 11 may be joined to the outer shell 1 by welding other than projection welding. Further, the guide piece 11b may extend straight below the mounting piece 11a so as not to be separated from the outer shell 1.

As shown in FIG. 2, the lower cap 2 has a disk-shaped flat circular mirror portion 2a and a conical tapered portion 2b that is inclined from the outer circumference of the mirror portion 2a toward the upper end side of the outer shell 1. And an annular flange portion 2c that projects horizontally outward from the outer circumference of the tapered portion 2b.

The lower cap 2 configured in this way is inserted into the outer shell 1 until the flange portion 2c is fitted into the inner diameter large diameter portion 1c on the lower end 1b side of the outer shell 1 and abuts on the step portion 1d. When the lower cap 2 is inserted into the inner circumference of the lower end 1b of the outer shell 1 in this way, it is surrounded by the inner diameter large diameter portion 1c of the outer shell 1 and the outer peripheral side of the lower cap 2 and the flange portion 2c and the tapered portion 2b. An annular gap G is formed inward of the lower end of the outer shell 1.

Then, in order to fix the lower cap 2 to the outer shell 1, the flange portion 2c of the lower cap 2 is provided in a state where the lower cap 2 is fitted to the inner diameter large diameter portion 1c on the lower end 1b side of the outer shell 1 as described above. And the large inner diameter portion 1c of the outer shell 1 are arc welded. When the lower cap 2 and the outer shell 1 are welded in this way, the welding rod and the base material of the lower cap 2 and the outer shell 1 are melted by the heat generated during welding, and the lower cap 2 and the outer shell 1 are combined. A weld bead B is formed at the joint.

The weld bead B is formed so as to bulge at the joint between the lower cap 2 and the outer shell 1. However, in the shock absorber D of the present embodiment, since the lower cap 2 is welded at a position shifted upward from the lower end 1b on the inner circumference of the outer shell 1, the inner circumference of the lower cap 2 and the outer shell 1 is welded. A gap G is formed between the two, and the weld bead B is stored in the gap G and does not protrude to the outer peripheral side of the outer shell 1.

Further, the tapered portion 2b on the outer circumference of the lower cap 2 is in contact with the lower end surface of the leg portion 7c at the lower end of the valve case 7. The lower end surface of the leg portion 7c at the lower end of the valve case 7 is a tapered surface along the tapered portion 2b. When the tapered portion 2b on the outer circumference of the lower cap 2 is provided in this way, the valve case 7 is aligned with the outer shell 1 and the cylinder 4 at a position coaxial with the outer shell 1 and the cylinder 4 by applying an axial force from the rod guide. Is fixed.

As shown in FIG. 3, the lower cap 2 is a disk-shaped curved surface portion that curves from the outer circumference of the mirror portion 2a toward the upper end side of the outer shell 1 on the outer circumference of the flat circular mirror portion 2a. It may be provided with 2d. In the lower cap 2 configured in this way, assuming that the lower cap 2 is fitted to the inner diameter large diameter portion 1c on the lower end 1b side of the outer shell 1, the inner diameter large diameter portion 1c of the outer shell 1 and the lower cap 2 An annular gap G on the outer peripheral side surrounded by the flange portion 2c and the curved surface portion 2d is formed. Therefore, even if a weld bead B is generated at the joint portion between the outer shell 1 and the lower cap 2 by arc welding, the weld bead B is stored by the gap G and does not protrude to the outer peripheral side of the outer shell 1. .. The lower cap 2 described above has a flange portion 2c on the outermost circumference, and the outer shell 1 has a step portion 1d on the inner circumference, but the lower cap 2 is displaced upward from the lower end 1b which was the inner circumference of the outer shell 1. If the lower cap 2 can be welded at the position below the bracket mounting portion 1a, one or both of the flange portion 2c and the step portion 1d can be omitted.

In the present embodiment, the bracket 3 is fitted to the outer periphery of the bracket mounting portion 1a of the outer shell 1 provided at the upper end of the arm portion 3b extending from the knuckle 3a holding the wheel of the vehicle and the upper end of the arm portion 3b. A bolt mounting piece having a C-shaped holding portion 3c that wraps the outer shell 1 and a hole (not shown) provided at both ends of the holding portion 3c that faces each other and allows the bolt 13 to be inserted. It is provided with 3d and 3e, and is a so-called knuckle carrier that is integrally connected to the knuckle 3a.

The bracket 3 configured in this way is attached to the outer shell 1 as follows. First, the lower end of the outer shell 1 is inserted into the holding portion 3c from the lower end 1b side of the outer shell 1, the upper end of the holding portion 3c is brought into contact with the lower end of the mounting piece 11a of the stopper 11, and the guide piece 11b Is inserted into the inside of the holding portion 3c. When the bracket 3 is inserted from the lower end 1b side of the outer shell 1, the weld bead B is stored in the gap G and does not protrude to the outer peripheral side of the outer shell 1, so that the outer shell 1 is inserted into the bracket 3. Does not interfere. Therefore, the outer shell 1 can be inserted into the bracket 3 even if the outer diameter on the lower side from the installation position of the stopper 11 of the outer shell 1 is straightened without reducing the diameter as in the shock absorber D of the present embodiment. ..

Returning, the holding portion 3c of the bracket 3 is restricted from rotating in the circumferential direction by the guide piece 11b, and the upward movement with respect to the outer shell 1 is restricted by the mounting piece 11a of the stopper 11, and the bracket mounting of the outer shell 1 is restricted. It is positioned on the outer periphery of the portion 1a. Then, when the bolt 13 is inserted into the holes of the bolt mounting pieces 3d and 3e and then the nut 14 is screwed into the bolt 13 and screwed in, the bolt mounting pieces 3d and 3e are attracted to each other and the holding portion 3c is contracted. The bracket mounting portion 1a of the outer shell 1 is gripped strongly and tightly, and the bracket 3 is firmly fixed to the bracket mounting portion 1a of the outer shell 1. The nut 14 may be omitted by using the bolt hole of any one of the bolt mounting pieces 3d and 3e as a female screw.

As described above, the shock absorber D of the present embodiment includes an outer shell 1 having a tubular shape and a bracket mounting portion 1a into which a bracket 3 connected to a knuckle supporting a wheel of a vehicle is fitted on the outer periphery on the lower end side. The lower end 1b of the outer shell 1 is provided with a lower cap 2 which is the inner circumference of the outer shell 1 and is welded at a position shifted from the lower end 1b of the outer shell 1 to the upper end side to close the opening on the lower end side of the outer shell 1. A gap G for storing the weld bead B generated at the joint between the outer shell 1 and the lower cap 2 is formed inside the outer shell 1. According to the shock absorber D configured in this way, the weld bead B generated at the joint between the outer shell 1 and the lower cap 2 is stored in the gap G and does not protrude to the outer peripheral side of the outer shell 1, so that the outer shell 1 The outer shell 1 can be inserted into the holding portion 3c of the bracket 3 without reducing the diameter of the lower end 1b of the bracket 3. As described above, according to the shock absorber D of the present embodiment, since it is not necessary to reduce the diameter of the lower end 1b of the outer shell 1, the outer shell 1 is located below the bracket mounting portion 1a and the bracket mounting portion 1a. The outer diameter can be the same, and the roundness of the bracket mounting portion 1a is not impaired.

As described above, in the shock absorber D of the present embodiment, the lower cap 2 is welded at a position shifted upward from the lower end 1b of the inner circumference of the outer shell 1 to provide a gap G for storing the weld bead B. The weld bead B interferes when the outer shell 1 is inserted into the bracket 3 without drawing down the lower end 1b of the outer shell 1. From the above, according to the shock absorber D of the present embodiment, since the drawing process itself for reducing the diameter of the lower end 1b of the outer shell 1 can be eliminated, not only the bracket 3 can be fitted to the outer shell 1 but also the bracket 3 can be fitted to the outer shell 1. A high roundness of the bracket mounting portion 1a can be realized. According to the shock absorber D of the present embodiment, since the drawing process itself for reducing the diameter of the lower end 1b of the outer shell 1 can be eliminated, the processing cost of the outer shell 1 is reduced, so that the shock absorber D can be manufactured at low cost. It becomes.

Further, in the conventional shock absorber, as shown in FIG. 4, when the outer shell T is provided with the small diameter portion t2, the diameter of the outer shell T is sharply reduced to provide the small diameter portion t2, and the bracket mounting portion t1 and the small diameter portion are provided. If the length of the portion between the bracket mounting portion t2 and the portion t2 is shortened, the shape change becomes severe and a problem in terms of strength occurs. Therefore, it is difficult to cut down the length of the portion t3 between the bracket mounting portion t1 and the small diameter portion t2. On the other hand, in the shock absorber D of the present embodiment, since the lower end 1b of the outer shell 1 does not have to be reduced in diameter, the bracket mounting portion 1a and the outer diameter on the lower side of the bracket mounting portion 1a can be made the same diameter. Since the length of the useless portion t3 can be omitted, the total length of the outer shell 1 can be shortened by that amount.

Even if the lower cap 2 has a flat disk shape, if it is welded to the inner circumference of the outer shell 1 at a position shifted upward from the lower end 1b, the inner circumference side of the lower end 1b of the outer shell 1 Since a gap for accommodating the weld bead B is formed in, a flat disk shape may be formed. However, when the lower cap 2 is disk-shaped and has a tapered portion 2b on the outer periphery as in the shock absorber D of the present embodiment, the mirror portion 2a which is the lower end of the lower cap 2 is arranged as downward as possible. However, the joint portion between the lower cap 2 and the outer shell 1 can be separated from the lower end 1b of the outer shell 1, and a large volume of the gap G for storing the weld bead B can be secured. As described above, when the lower cap 2 has a disk shape and is provided with the tapered portion 2b on the outer periphery, the mirror portion 2a of the lower cap 2 is arranged downward as compared with the case where the lower cap 2 has a flat disk shape. The valve case 7 can also be arranged below the outer shell 1. The fact that the valve case 7 can be arranged below the outer shell 1 leads to a wider limit of downward movement of the piston 6 with respect to the outer shell 1, so that it becomes easier to secure the stroke length of the shock absorber D. Therefore, when the lower cap 2 is disk-shaped and the outer peripheral portion is provided with the tapered portion 2b, the shock absorber D is used to secure the same stroke length as compared with the case where the lower cap 2 is flat and disk-shaped. The total length of the cylinder 4 and the outer shell 1 can be further shortened, and the total length of the piston rod 5 can be shortened, so that the shock absorber D can be made lighter. The advantage of being able to shorten the overall length and reduce the weight of the shock absorber D can also be enjoyed by the shock absorber D in which the lower cap 2 has a disk shape and has a curved surface portion 2d instead of the tapered portion 2b on the outer periphery. Further, in order to enjoy the above-mentioned advantage, not only the outer periphery of the lower cap 2 but also the entire lower cap 2 may be formed in a curved surface shape.

Further, in the shock absorber D of the present embodiment, the lower end of the lower cap 2 is arranged above the lower end 1b of the outer shell 1 when viewed from the radial direction, and the entire lower cap 2 is housed in the outer shell 1. Has been done. According to the shock absorber D configured in this way, the entire lower cap 2 is housed in the outer shell 1, so that when the shock absorber D is mounted on the vehicle via the bracket 3, the lower cap 2 and the drive shaft are mounted. Interference with can be effectively avoided.

Further, as described above, in the shock absorber D of the present embodiment, the lower cap 2 is positioned axially with respect to the outer shell 1 by the step portion 1d provided on the inner circumference of the outer shell 1. The step portion 1d is provided at a position separated from the position where the bracket mounting portion 1a of the outer shell 1 is provided toward the lower end 1b side in the axial direction. When the lower cap 2 is welded to the outer shell 1 while being positioned by the step portion 1d, the lower cap 2 is welded at a position separated from the bracket mounting portion 1a toward the lower end side of the outer shell 1, so that the lower cap 2 is welded. The bracket mounting portion 1a is not distorted by the welding of the bracket mounting portion 1a, and the roundness of the bracket mounting portion 1a is not adversely affected. By providing the step portion 1d, the joint portion of the lower cap 2 by welding to the outer tube 1 can be easily positioned at a position separated from the bracket mounting portion 1a toward the lower end side of the outer tube 1 in the axial direction. The lower cap 2 may be welded so that the joint portion is separated from the bracket mounting portion 1a without providing the portion 1d. Further, the axial positioning of the lower cap 2 with respect to the outer shell 1 is performed by restricting the movement of the lower cap 2 to the inner side into the outer shell 1, so that the inner circumference of the outer shell 1 is not only the step portion 1d. A protrusion may be provided on the outer shell 1, or a groove may be provided on the inner circumference of the outer shell 1 to fit a C ring or the like into the groove. The cutting process for providing the step portion 1d does not adversely affect the roundness of the bracket mounting portion 1a as in the process of crimping the outer tube 1 from the outer circumference to provide a protrusion, and uses a C ring that increases the number of parts. Cost increase can be avoided for things.

Although the bracket 3 is a knuckle carrier in the drawing, when the shock absorber D is incorporated into a double wishbone suspension, it is disclosed in FIGS. 1 to 5 of JP-A-2003-104020. It may be a bifurcated fork bracket that connects the shock absorber D to the lower arm that swingably connects the knuckle to the vehicle body. As described above, the bracket 3 may be directly connected to the knuckle or indirectly via another component, or may be integrally connected to the knuckle.

Although the preferred embodiments of the present invention have been described in detail above, they can be modified, modified, and modified as long as they do not deviate from the claims.

1 ... Outer shell, 1a ... Bracket mounting part, 1b ... Lower end of outer shell, 2 ... Lower cap, 2b ... Tapered part, 2d ... Curved surface part, 3 ... Bracket , B ... weld bead, D ... shock absorber, G ... void

Claims (6)

An outer shell that is tubular and has a bracket mounting part on the outer circumference on the lower end side where a bracket connected to a knuckle that supports the wheels of the vehicle is fitted.
It is provided with a lower cap which is the inner circumference of the outer shell and is welded at a position shifted from the lower end side of the outer shell to the upper end side to close the opening on the lower end side of the outer shell.
A shock absorber characterized in that a gap for storing a weld bead generated at a joint between the outer shell and the lower cap is formed inside the lower end of the outer shell. The shock absorber according to claim 1, wherein the lower cap has a disk shape and has a tapered portion whose outer circumference is inclined toward the upper end side of the outer shell. The shock absorber according to claim 1, wherein the lower cap has a disk-shaped curved surface portion whose outer periphery is curved toward the upper end side of the outer shell. The shock absorber according to any one of claims 1 to 3, wherein the lower cap is entirely housed inside the outer shell. The buffer according to any one of claims 1 to 4, wherein the lower cap is welded to the outer shell at a position separated from the bracket mounting portion toward the lower end side of the outer shell. vessel. The shock absorber according to any one of claims 1 to 5, wherein the bracket is a knuckle carrier integrated with the knuckle.

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