JP7389447B2 - hydraulic shock absorber - Google Patents

Description

The present invention relates to a hydraulic shock absorber.

Conventionally, as described in Patent Documents 1 and 2, hydraulic shock absorbers include a damper cylinder that is attached to one of the vehicle body side and the axle side, and a damper cylinder that is attached to the other side of the vehicle body and the axle side and slides through the oil chamber in the damper cylinder. a piston rod that moves to extend and contract with respect to the damper cylinder; a suspension spring interposed between a protruding end side of the piston rod protruding from the damper cylinder; and an outer periphery of the damper cylinder; and one end of the damper cylinder. a bump stopper which is disposed at the end of the piston rod and which a bump rubber provided on the side of the above-mentioned protruding end of the piston rod comes into contact with when the piston rod is retracted; Some damper cylinders have a dust boot extending around the damper cylinder from the side of the protruding end of the damper cylinder.

In the hydraulic shock absorber described in Patent Document 1, the end of the dust boot extending around the damper cylinder comes into contact with the lowest end of the bump stopper even when the piston rod protrudes to the maximum extent. This ensures that surrounding dust and rain water does not reach the piston rod protruding from the damper cylinder.

The hydraulic shock absorber described in Patent Document 2 includes a cylindrical support body attached to the outer periphery of a damper cylinder and supported by an engaging portion provided on the damper cylinder in the axial direction of the damper cylinder; It has a vehicle height adjustment seat that is screwed onto a threaded portion provided on the outer periphery of the support body to support a suspension spring and enable the vehicle height to be adjusted. The landing position can be adjusted and the vehicle height can be adjusted.

Japanese Patent Application Publication No. 2007-211949 Jito No. 3060695 Publication

However, the hydraulic shock absorber described in Patent Document 1 includes a vehicle height adjustment seat that is screwed onto a threaded portion provided on the outer periphery of a cylindrical support body to carry a suspension spring and to enable the vehicle height to be adjusted. It is not possible to adjust the vehicle height.

Furthermore, the hydraulic shock absorber described in Patent Document 2 does not include a mounting part to which the end of the dust boot is attached to the outer periphery of the bump stopper, so that dust and rainwater do not reach the piston rod protruding from the damper cylinder. It is not possible to reliably avoid this.

An object of the present invention is to provide a hydraulic shock absorber with a simple structure that reliably prevents dust and rainwater from reaching a piston rod protruding from a damper cylinder, and also allows vehicle height adjustment.

The invention according to claim 1 includes a damper cylinder that is attached to one of the vehicle body side and the axle side, and a damper cylinder that is attached to the other side of the vehicle body and the axle side, and that slides in an oil chamber in the damper cylinder to the damper cylinder. a suspension spring interposed between an extensible piston rod, a protruding end side of the piston rod protruding from the damper cylinder, and the outer periphery of the damper cylinder; a suspension spring disposed at one end of the damper cylinder; A bump stopper, which the bump rubber provided on the side of the projecting end of the piston rod comes into contact with when the piston rod contracts, and a bump stopper that is provided on the side of the projecting end of the piston rod, and a bump stopper that contacts the bump rubber provided on the side of the projecting end of the piston rod. A hydraulic shock absorber having a dust boot extending around the circumference, the hydraulic shock absorber being attached to the outer periphery of a damper cylinder and supported by an engaging portion provided on the damper cylinder in the axial direction of the damper cylinder. The bump stopper has a cylindrical support body, and a vehicle height adjustment seat that is screwed onto a threaded portion provided on the outer periphery of the cylindrical support body to support a suspension spring and enable the vehicle height to be adjusted. It is welded to the end face of the cylindrical support body provided with the above-mentioned threaded part on the outer periphery, which is located near one end of the damper cylinder, and with a gap between it and the one end of the damper cylinder in the axial direction of the damper cylinder. , the end of the dust boot is attached to a mounting portion provided on the outer periphery of the bump stopper that is welded to the end surface of the cylindrical support .

In the invention according to claim 2, in the invention according to claim 1, the cylindrical support further includes a small diameter outer circumference on one end side of the damper cylinder, and a shoulder on the small diameter outer circumference in the axial direction of the damper cylinder. The damper cylinder is attached to a large-diameter outer circumferential portion connected to the damper cylinder via a shoulder-shaped engagement portion, and is supported by the shoulder-shaped engagement portion in the axial direction of the damper cylinder.

(Claim 1)
(a) The hydraulic shock absorber is equipped with a vehicle height adjustment seat that is screwed onto a threaded portion provided on the outer periphery of a cylindrical support to carry a suspension spring and enable adjustment of the vehicle height, and the cylindrical support The outer periphery of the bump stopper attached to the end face of the dust boot is provided with a mounting portion to which the end of the dust boot is attached. Therefore, with the simple structure of attaching the bump stopper to the end face of the cylindrical support, the processability and assemblage of the bump stopper and the cylindrical support are improved, and the dust boot attached to the attachment part on the outer periphery of the bump stopper is improved. The presence of the damper cylinder ensures that dust and rainwater do not reach the piston rod protruding from the damper cylinder, and the presence of a height adjustment seat screwed onto the outer periphery of the cylindrical support allows the vehicle height to be adjusted. .

(b) In (a) above, the bump stopper is attached to the end surface of the cylindrical support supported by the engaging portion provided on the damper cylinder in the axial direction of the damper cylinder, and A gap was provided between the damper and one end of the damper cylinder. Therefore, the load exerted by the suspension spring on the vehicle height adjustment seat and the load exerted by the bump rubber on the bump stopper are supported by the engaging portion provided on the damper cylinder via the cylindrical support. This means that only compressive stress acts on the joint between the bump stopper and the cylindrical support, which means that the joint between them does not need to be strong and can be simplified (bump stopper When the bump stopper is in contact with one end of the damper cylinder without a gap in the axial direction of the damper cylinder, tensile stress acts on the joint between the bump stopper and the cylindrical support, and both of them (requires a strong bond between them).

(c) In (a) above, the dust extending around the damper cylinder is provided with a threaded portion on the outer periphery of the cylindrical support attached to the outer periphery of the damper cylinder, into which the vehicle height adjustment seat is screwed. The end of the boot is attached to a mounting portion provided on the outer periphery of the bump stopper. Therefore, there is no risk that the end of the dust boot will come into contact with the threaded portion on the outer periphery of the cylindrical support and be damaged.

(Claim 2)
(d) The cylindrical support is attached to the small diameter outer periphery on one end side of the damper cylinder and the large diameter outer periphery that connects to the small diameter outer periphery via a shoulder-shaped engagement part in the axial direction of the damper cylinder. and is supported by the shoulder-shaped engaging portion in the axial direction of the damper cylinder. Therefore, the cylindrical support body to which the bump stopper is attached can be easily and reliably supported by the simple shoulder-shaped engagement portion formed on the outer periphery of the damper cylinder.

(Claim 1 )
(e) The bump stopper is welded to the end face of the cylindrical support. This welding does not require strength due to the above-mentioned (b), and a simple welded structure such as brazing is sufficient.

FIG. 1 is a perspective view showing a hydraulic shock absorber according to an embodiment of the present invention. FIG. 2 is a sectional view showing the hydraulic shock absorber. FIG. 3 is an exploded perspective view showing the hydraulic shock absorber. FIG. 4 is an enlarged sectional view of the main parts of the hydraulic shock absorber. FIG. 5 is a perspective view of the vehicle height adjustment assembly. FIG. 6 is a sectional view showing the vehicle height adjustment assembly. FIG. 7 is an exploded perspective view showing the vehicle height adjustment assembly.

As shown in FIGS. 1 to 4, a hydraulic shock absorber 100 according to an embodiment of the present invention is attached to one of the vehicle body side and the axle side, in this embodiment, the axle side via a knuckle (not shown). It has a damper cylinder 10. In this embodiment, a cylindrical inner tube 11 and a cylindrical outer tube 12 constitute a double-tube type damper cylinder 10. A rod guide device 13 is fixed to the upper end of the damper cylinder 10, and the rod guide device 13 is held between the upper end of the inner tube 11 and the upper end crimped portion 12A of the outer tube 12. The lower end of the damper cylinder 10 is sealed by a bottom cap 12B that is inserted into and fixed to the inner diameter of the lower end of the outer tube 12. An oil chamber 14 is formed inside the inner tube 11, and a reservoir chamber 15 is formed in the annular space between the inner tube 11 and the outer tube 12. The oil chamber 14 and the reservoir chamber 15 are filled with hydraulic oil, and the side of the rod guide device 13 in the reservoir chamber 15 is filled with pressurized gas.

The hydraulic shock absorber 100 is attached to a vehicle body side mounting bracket 20 that is fixed to the other side of the vehicle body and the axle side, in this embodiment, the vehicle body side, and connects the oil chamber 14 in the inner tube 11 constituting the damper cylinder 10. It has a piston rod 30 that slides and expands and contracts with respect to the damper cylinder 10. In this embodiment, the piston rod 30 is attached to the vehicle body side mounting bracket 20 via a pillow block 21 fixed to a protruding end that extends outward through a rod guide device 13 provided on the damper cylinder 10. The pillow block 21 is fixed to the above-mentioned protruding end of the piston rod 30 by a nut 22. A piston 31 is fixed to the insertion end of the piston rod 30 into the damper cylinder 10, and the piston 31 is slidably accommodated in the inner tube 11 within the oil chamber 14 of the inner tube 11.

The hydraulic shock absorber 100 includes a piston valve device 32 on the piston 31 and a base valve device 33 on the lower end of the inner tube 11 . The piston valve device 32 is configured by installing a compression-side damping valve and a rebound-side damping valve in a compression-side oil passage and a rebound-side oil passage that communicate the upper and lower chambers of the oil chamber 14 that sandwich the piston 31 therebetween. The base valve device 33 is configured by installing a compression side damping valve and a rebound side damping valve in a pressure side oil passage and a growth side oil passage that communicate the lower part of the oil chamber 14 and the reservoir chamber 15. The piston valve device 32 and the base valve device 33 generate a compression side damping force during the compression stroke of the hydraulic shock absorber 100, and generate a rebound side damping force during the extension stroke of the hydraulic shock absorber 100, thereby reducing the impact of the suspension spring 40, which will be described later. To suppress expansion and contraction vibration between the damper cylinder 10 and the piston rod 30 due to force absorption.

The hydraulic shock absorber 100 has a suspension spring 40 interposed between the above-mentioned protruding end side of the piston rod 30 protruding from the damper cylinder 10 and the outer periphery of the damper cylinder 10. The suspension spring 40 is interposed between a spring receiver 41 provided on the lower surface of the vehicle body side mounting bracket 20 and a vehicle height adjustment seat 83 provided on the outer periphery of the damper cylinder 10 as described later. The impact force that the vehicle receives from the road surface is absorbed by the spring force of the suspension spring 40.

The hydraulic shock absorber 100 has a bump stopper 50 arranged at one end (upper end) of the damper cylinder 10. A bump rubber 60 provided on the side of the above-mentioned protruding end of the piston rod 30 comes into contact with the bump stopper 50 when the piston rod 30 contracts. In this embodiment, the bump stopper 50 is arranged around the upper end side of the outer tube 12 in the damper cylinder 10, receives the bump rubber 60 that descends as the piston rod 30 contracts, and prevents the damper cylinder 10 from moving as much as possible. To avoid bottoming out caused by the piston rod 30 contracted to contact other parts.

The hydraulic shock absorber 100 has a dust boot 70 extending from the above-mentioned protruding end side of the piston rod 30 around the damper cylinder 10 in an annular space between the piston rod 30 and the suspension spring 40 . The upper end of the dust boot 70 is interposed and held between the spring receiver 41 provided on the lower surface of the vehicle body side mounting bracket 20 and the upper end of the suspension spring 40. The mounting structure for the lower end of the dust boot 70 will be described later. The dust boot 70 has a bellows shape made of an elastic material such as rubber, expands and contracts in accordance with the expansion and contraction of the piston rod 30 with respect to the damper cylinder 10, and covers the entire range of the piston rod 30 protruding from the damper cylinder 10. The dust boot 70 prevents surrounding dust and rainwater from reaching the piston rod 30 protruding from the damper cylinder 10.

However, the hydraulic shock absorber 100 of this embodiment has a vehicle height adjustment assembly 100A as shown in FIGS. It has a cylindrical support body 80 supported by an engaging portion 12T provided on the cylinder 10. The cylindrical support 80 of this embodiment has an elongated cylindrical shape that is attached to the outer periphery of the outer cylinder 12 in the damper cylinder 10, and includes a small diameter inner circumferential portion 80S on the upper end side, and a small diameter inner circumferential portion 80S on the upper end side. A large-diameter inner circumferential portion 80L on the lower end side is connected via a tapered locking portion 80T whose diameter expands downward. Thereby, the cylindrical support body 80 connects each of the small diameter inner peripheral part 80S and the large diameter inner peripheral part 80L to the small diameter outer peripheral part 12S on the one end (upper end) side of the outer tube 12 and the axis of the outer tube 12. It is attached to each of the large-diameter outer circumferential parts 12L connected to the small-diameter outer circumferential part 12S via tapered shoulder-shaped engaging parts 12T whose diameter expands downward in the direction, and the locking parts 80T are attached to the small-diameter outer circumferential parts 12S in the axial direction of the outer tube 12. and is supported by the shoulder-shaped engaging portion 12T. The cylindrical support 80 supported by the shoulder-like engagement portion 12T is fixed to the large diameter outer peripheral portion 12L of the outer tube 12 by a set screw 81 screwed into the lower end thereof.

The vehicle height adjustment assembly 100A also includes a vehicle height adjustment seat 83 that is screwed onto a threaded portion 82 provided on the outer periphery of the cylindrical support 80 to support the lower end of the suspension spring 40 and enable vehicle height adjustment. have A lock nut 84 is also screwed onto the threaded portion 82 of the cylindrical support 80 , and the lock nut 84 comes into contact with the lower end surface of the vehicle height adjustment seat 83 to screw the vehicle height adjustment seat 83 onto the threaded portion 82 . Allows to be fixed in position. The vehicle height adjustment seat 83 and the lock nut 84 are provided with engaging portions 83A and 84A at a plurality of positions on their outer circumferences, which can be engaged with a rotary operation tool such as a wrench. The vehicle height can be adjusted by screwing the vehicle height adjusting seat 83 onto the threaded portion 82 of the cylindrical support 80 and changing the screwing position of the vehicle height adjusting seat 83 in the axial direction of the damper cylinder 10. .

In the vehicle height adjustment assembly 100A, the bump stopper 50 is located at one end of the damper cylinder 10 (the upper end caulking portion of the outer tube 12) in the cylindrical support 80 supported by the shoulder-like engagement portion 12T of the outer tube 12. 12A) is attached to the end face (upper end face) 80A that will be located closer to the upper end face of one end of the damper cylinder 10 (the upper end caulking portion 12A of the outer tube 12) in the axial direction of the damper cylinder 10. A mounting portion 51 to which the lower end of the dust boot 70 is attached is provided on the outer periphery of the bump stopper 50 with a gap G (FIG. 4) interposed therebetween. The bump stopper 50 of this embodiment is welded to the end surface 80A of the cylindrical support 80 by brazing or the like. W (Fig. 4) indicates a welded part.

The attachment portion 51 of the present embodiment includes an annular groove 51 recessed in the outer periphery of the bump stopper 50, and is attached to the dust boot 70 with its lower end latched thereto. However, the attachment portion 51 may be formed of an annular convex portion or the like provided on the outer periphery of the bump stopper 50.

Therefore, according to this embodiment, the following effects are achieved.
(a) The hydraulic shock absorber 100 includes a vehicle height adjustment seat 83 that is screwed onto a threaded portion 82 provided on the outer periphery of a cylindrical support body 80 to support the suspension spring 40, and allows the vehicle height to be adjusted. The outer periphery of the bump stopper 50 attached to the end surface 80A of the cylindrical support 80 is provided with an annular groove 51 in which the lower end of the dust boot 70 can be engaged. Therefore, with the simple structure of attaching the grooved bump stopper 50 to the end surface 80A of the cylindrical support 80, the processability and assembly of the bump stopper 50 and the cylindrical support 80 can be improved. The presence of the dust boot 70 that can be locked in the annular groove 51 reliably prevents dust and rainwater from reaching the piston rod 30 protruding from the damper cylinder 10, and also prevents the dust boot 70 from being screwed onto the outer periphery of the cylindrical support 80. Due to the presence of the vehicle height adjustment seat 83, the vehicle height can be adjusted.

(b) In (a) above, the bump stopper 50 is attached to the end face 80A of the cylindrical support 80 supported by the engaging portion 12T provided on the damper cylinder 10 in the axial direction of the damper cylinder 10, and A gap G is provided between the cylinder 10 and one end of the damper cylinder 10 in the axial direction of the cylinder 10. Therefore, the load exerted by the suspension spring 40 on the vehicle height adjustment seat 83 and the load exerted by the bump rubber 60 on the bump stopper 50 are supported by the engaging portion 12T provided on the damper cylinder 10 via the cylindrical support body 80. Ru. This means that only compressive stress acts on the joint between the bump stopper 50 and the cylindrical support 80, and the joint between the two does not need to be strong and can be simplified. When the bump stopper 50 is in contact with one end of the damper cylinder 10 in the axial direction of the damper cylinder 10 without a gap G, a tension is applied to the joint between the bump stopper 50 and the cylindrical support 80. stress and requires a strong bond between the two).

(c) In the above (a), while providing the threaded portion 82 on the outer periphery of the cylindrical support 80 attached to the outer periphery of the damper cylinder 10 to which the vehicle height adjustment seat 83 is screwed, The lower end of the extended dust boot 70 is locked in an annular groove 51 provided on the outer periphery of the bump stopper 50. Therefore, there is no risk that the lower end of the dust boot 70 will come into contact with the threaded portion 82 on the outer periphery of the cylindrical support 80 and be damaged.

(d) The cylindrical support body 80 includes a small diameter outer circumferential portion 12S on one end side of the damper cylinder 10, and a large diameter portion connected to the small diameter outer circumferential portion 12S in the axial direction of the damper cylinder 10 via a shoulder-like engagement portion 12T. It is attached to the radially outer peripheral portion 12L and supported by the shoulder-shaped engaging portion 12T in the axial direction of the damper cylinder 10. Therefore, the cylindrical support body 80 to which the bump stopper 50 is attached can be easily and reliably supported by the simple shoulder-shaped engagement portion 12T formed on the outer periphery of the damper cylinder 10.

(e) The bump stopper 50 is welded to the end surface 80A of the cylindrical support 80. This welding does not require strength due to the above-mentioned (b), and a simple welded structure such as brazing is sufficient.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration of the present invention is not limited to these embodiments, and the design may be changed without departing from the gist of the present invention. Included in the present invention. For example, the bump stopper 50 and the cylindrical support 80 are not necessarily coupled by the weld W or the like, and the bump stopper 50 may be placed on the end surface 80A of the cylindrical support 80.

Further, the bump stopper 50 and the cylindrical support body 80 may be integrally formed by machining a single material, or by casting.

Furthermore, the engaging portion 12T and the locking portion 80T do not necessarily need to be tapered.

According to the present invention, in a hydraulic shock absorber, with a simple configuration, it is possible to reliably prevent dust and rainwater from reaching a piston rod protruding from a damper cylinder, and also to enable vehicle height adjustment.

100 Hydraulic shock absorber 10 Damper cylinder 12S Small diameter outer peripheral part 12L Large diameter outer peripheral part 12T Shoulder-shaped engaging part (engaging part)
30 Piston rod 40 Suspension spring 50 Bump stopper 51 Mounting part (annular groove)
60 Bump rubber 70 Dust boot 80 Cylindrical support 80A End face 82 Threaded portion 83 Vehicle height adjustment seat G Gap W Welded portion

Claims (2)

A damper cylinder installed on one of the vehicle body side and the axle side,
a piston rod that is attached to the other of the vehicle body side and the axle side and extends and contracts with respect to the damper cylinder by sliding in an oil chamber in the damper cylinder;
a suspension spring interposed between a protruding end side of the piston rod protruding from the damper cylinder and an outer periphery of the damper cylinder;
a bump stopper disposed at one end of the damper cylinder, with which a bump rubber provided on the side of the protruding end of the piston rod comes into contact when the piston rod contracts;
A hydraulic shock absorber comprising a dust boot extending from the side of the protruding end of the piston rod around the damper cylinder in an annular space between the piston rod and the suspension spring,
a cylindrical support that is attached to the outer periphery of the damper cylinder and supported by an engaging portion provided on the damper cylinder in the axial direction of the damper cylinder;
It has a vehicle height adjustment seat that is screwed onto a threaded portion provided on the outer periphery of the cylindrical support body, supports a suspension spring, and allows the vehicle height to be adjusted;
The bump stopper is welded to an end surface of the cylindrical support body provided with the threaded portion on the outer periphery, which is located near one end of the damper cylinder, and is arranged between the bump stopper and the one end of the damper cylinder in the axial direction of the damper cylinder. A hydraulic shock absorber in which an end of a dust boot is attached to an attachment part provided on the outer periphery of the bump stopper which is welded to the end surface of the cylindrical support with a gap between the bump stopper and the bump stopper. The cylindrical support body is attached to a small-diameter outer circumferential portion on one end side of the damper cylinder and a large-diameter outer circumferential portion that is connected to the small-diameter outer circumferential portion via a shoulder-like engagement portion in the axial direction of the damper cylinder, The hydraulic shock absorber according to claim 1, wherein the hydraulic shock absorber is supported by the shoulder-like engagement portion in the axial direction of the damper cylinder.

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