JP3719532B2 - Hydraulic shock absorber for vehicles - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a vehicular hydraulic shock absorber used for an automobile or a motorcycle, and more particularly to a vehicular hydraulic shock absorber using a single tube type cylinder.
[0002]
[Prior art]
In a vehicle hydraulic shock absorber used for an automobile or motorcycle, a hydraulic oil is filled in a cylinder, a piston is slidably disposed, and a damping valve that generates a damping force is provided on the piston. is set up. One end of a piston rod is coupled to the piston, and the other end of the piston rod extends outside the cylinder. A suspension spring is interposed between the piston rod and the cylinder, and the hydraulic shock absorbers are disposed on the vehicle body side and the axle side. The impact from the road surface is absorbed by the suspension spring, and the vibration of the vehicle body is suppressed by the damping valve of the hydraulic shock absorber.
[0003]
Further, the vehicle hydraulic shock absorber needs to be provided with a reservoir chamber that compensates for the hydraulic oil corresponding to the volume change caused by the piston rod entering or leaving the cylinder. Some single-tube hydraulic shock absorbers having a single cylinder tube are provided with a reservoir tank outside the cylinder, and the reservoir tank functions as the reservoir chamber.
[0004]
[Problems to be solved by the invention]
If the reservoir tank is cast and formed integrally with the cylinder, for example, from aluminum or an aluminum alloy, the cylinder is cast and the cost increases.
[0005]
In addition, as in the idea described in Japanese Utility Model Publication No. 2-40135, a cylinder is formed with a low-cost steel pipe, and a bracket in which a flow path communicating with a reservoir tank is formed on the outer periphery of the cylinder is fastened and fixed. In such a case, since the tightening bolt is tightened by using the slit portion of the bracket, the size of the bracket increases and the cost increases.
[0006]
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a vehicle hydraulic shock absorber that can reduce the cost by simplifying the structure of a joint bracket for a reservoir tank.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is a vehicle hydraulic shock absorber in which a piston is slidably fitted inside a cylinder filled with hydraulic oil, and one end of the cylinder is closed by an end cap, The end cap is integrally formed with a flange portion that extends outward from the outer periphery of the cylinder, and the cylinder is formed with an opening hole, and a communication passage that connects the opening hole and the reservoir tank is formed. The formed joint bracket is rotatably fitted on the outer periphery of the cylinder and locked by the flange portion of the end cap, and the joint bracket is non-rotatably coupled to the cylinder .
[0008]
The invention according to claim 2 is the invention according to claim 1, wherein the joint bracket is non-rotatably coupled to a flange portion of an end cap that closes one end of the cylinder .
[0009]
The invention according to claim 3 is the invention according to claim 1 or 2, wherein the joint bracket is formed integrally with the reservoir tank, and the communication path of the joint bracket communicates with the oil chamber of the reservoir tank. It is.
[0010]
According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the joint bracket is connected to the reservoir tank via a flexible hose, and the communication path of the joint bracket is the flexible hose. And communicated with the oil chamber of the reservoir tank via
[0011]
The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the joint bracket is integrally formed with a spring receiving portion for supporting a suspension spring disposed on the outer periphery of the cylinder. It is.
[0013]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a side view showing a part of a first embodiment of a vehicle hydraulic shock absorber according to the present invention in a cross-sectional state taken along line II of FIG. FIG. 2 is a view taken in the direction of arrow II in FIG. FIG. 3 is an enlarged cross-sectional view of a part of FIG.
[0014]
As shown in FIG. 1, a hydraulic shock absorber 10 used in a four-wheeled vehicle is integrated with a suspension spring 11 to form a cushion unit, and the cushion unit is disposed on the vehicle body side and the axle side. The suspension spring 11 absorbs an impact from the road surface, and the hydraulic shock absorber 10 attenuates the vibration of the cushion unit to suppress the vehicle body.
[0015]
The hydraulic shock absorber 10 is configured such that a cylinder 12 made of a single tube is filled with hydraulic oil, a piston 13 is slidably fitted, and one end of a piston rod 14 is coupled to the piston 13. One end of the cylinder 12 can be closed with an end cap 15 and the other end can be closed with a rod guide 16 in a liquid-tight manner. The other end of the piston rod 14 extends through the rod guide 16 to the outside of the cylinder 12. Further, the piston 13 divides the inside of the cylinder 12 into an upper chamber 17A and a lower chamber 17B. The piston rod 14 can enter or leave the upper chamber 17A.
[0016]
One end of the piston rod 14 is penetrated and fixed at the center position of the piston 13. In the piston 13, a plurality of oil passages 18 penetrates and is formed around the piston rod 14, and a damping valve 19 is installed on one side of the piston 13. An orifice (not shown) is formed in the damping valve 19 at a position corresponding to the oil flow path 18.
[0017]
In the compression process of the hydraulic shock absorber 10, the working oil in the lower chamber 17 </ b> B bends and deforms the damping valve 19 through the oil flow path 18, and this damping valve 19 functions as a check valve so that the working oil is in the upper chamber 17 </ b> A. Flow into. Accordingly, in this compression process, the hydraulic shock absorber 10 does not generate a damping force.
[0018]
Further, during the extension process of the hydraulic shock absorber 10, the working oil in the upper chamber 17 </ b> A flows into the lower chamber 17 </ b> B through the orifice of the damping valve 19 and the oil passage 18. The hydraulic shock absorber 10 generates a damping force (extension side damping force) while the hydraulic oil flows through the orifice.
[0019]
In the figure, reference numeral 20 denotes a reband spring, reference numeral 21 denotes an oil seal, and reference numeral 22 denotes an axle bracket welded to the end cap 15.
[0020]
The end cap 15 is integrally formed with a flange portion 23 that extends outward from the outer periphery of the cylinder 12. The reservoir tank 24 is integrally formed with the joint bracket 25, and the insertion hole 26 of the joint bracket 25 is rotatably fitted to the cylinder 12. The joint bracket 25 is locked to the flange portion 23, and the flange portion 23 supports the load of the reservoir tank 24 and the spring load of the suspension spring 11 described later.
[0021]
As shown in FIG. 2, the flange portion 23 is formed with notches 27 at two positions opposite to each other in the diameter direction of the end cap 15, and as shown in FIG. 28 is fitted into the notch 27. By means of this locking bolt 28, the joint bracket 25 is prevented from rotating with respect to the flange portion 23 of the end cap 15.
[0022]
The joint bracket 25 is integrally formed with a lower spring receiving portion 37 that supports the load of the suspension spring 11. Therefore, the load of the suspension spring 11 is supported by the flange portion 23 of the end cap 15 via the lower spring receiving portion 37 of the joint bracket 25.
[0023]
As shown in FIG. 1, the reservoir tank 24 has a function of compensating the hydraulic oil for the volume change of the piston rod 14 that enters or exits into the upper chamber 17 </ b> A during the compression or expansion process of the hydraulic shock absorber 10. The reservoir tank 24 is configured such that a free piston 30 is slidably fitted in a tank housing 29 and an opening is closed by a tank cap 31. The inside of the tank housing 29 is partitioned by a free piston 30 into a gas chamber 32 filled with air and an oil chamber 33 filled with hydraulic oil. The oil chamber 33 communicates with one end of a communication path 34 formed in the joint bracket 25. An annular groove 35 is formed in the joint bracket 25 on the other end side of the communication passage 34, and an opening hole 36 is opened in the cylinder 12 at a position corresponding to the annular groove 35. Accordingly, the oil chamber 33 of the reservoir tank 24 communicates with the lower chamber 17B of the cylinder 12 via the communication passage 34, the annular groove 35, and the opening hole 36.
[0024]
Therefore, in the compression process of the hydraulic shock absorber 10, the hydraulic oil in the lower chamber 17B of the cylinder 12 flows into the upper chamber 17A through the oil flow path 18 of the piston 13, and the negative pressure in the upper chamber 17A is eliminated. At the same time, the hydraulic oil corresponding to the increased volume of the piston rod 14 entering the upper chamber 17A flows into the oil chamber 33 of the reservoir tank 24 from the lower chamber 17B via the opening hole 36, the annular groove 35 and the communication passage 34. .
[0025]
Further, during the extension process of the hydraulic shock absorber 10, the hydraulic oil in the upper chamber 17 </ b> A of the cylinder 12 flows into the lower chamber 17 </ b> B through the orifice of the damping valve 19 and the oil flow path 18 of the piston 13 to generate a damping force. At the same time, the hydraulic oil corresponding to the volume reduction of the piston rod 14 that retreats from the upper chamber 17A of the cylinder 12 enters the lower chamber 17B from the oil chamber 33 of the reservoir tank 24 through the communication passage 34, the annular groove 35, and the opening hole 36. It flows in and the negative pressure in this lower chamber 17B is eliminated.
[0026]
According to the above embodiment, the joint bracket 25 for the reservoir tank 24 is rotatably fitted on the outer periphery of the cylinder 12 and is locked to the flange portion 23 of the end cap 15, and the joint bracket 25 is attached to the end cap 15. Since it is non-rotatably coupled to the flange portion 23 using the non-rotating bolt 28, the coupling structure of the joint bracket 25 to the cylinder 12 does not increase in size, and the structure can be simplified. Also, the reservoir tank 24 and the joint bracket 25 can be integrally cast and formed of aluminum or an aluminum alloy, and the cylinder 12 can be formed of, for example, a low-cost steel pipe. From these things, the cost as the whole of the hydraulic shock absorber 10 can be reduced.
[0027]
In addition, a lower spring receiving portion 37 for the suspension spring 11 is formed integrally with the joint bracket 25. The joint bracket 25 also serves as a spring receiver, and the flange portion 23 of the end cap 15 ensures the spring load of the suspension spring 11. Therefore, it is not necessary to install the lower spring receiver 37 separately from the joint bracket 25. Also from this point, the number of parts can be reduced and the cost of the hydraulic shock absorber 10 can be reduced.
[0028]
FIG. 4 is a side view showing a second embodiment of the vehicle hydraulic shock absorber according to the present invention in a sectional state along the line IV-IV in FIG. FIG. 5 is a view taken in the direction of arrow V in FIG. 6 is an enlarged cross-sectional view of a part of FIG. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.
[0029]
In the hydraulic shock absorber 39 of this embodiment, the joint bracket 40 is formed separately from the reservoir tank 41, and both are connected by a flexible hose 42. Both ends of the flexible hose 42 are fitted into the mounting holes 43 of the joint bracket 40 and the mounting holes 44 of the reservoir tank 41, respectively. Accordingly, the oil chamber 33 of the reservoir tank 41 communicates with the lower chamber 17B of the cylinder 12 through the attachment hole 43, the flexible hose 42, the attachment hole 44, the annular groove 35, and the opening hole 36 of the cylinder 12.
[0030]
The joint bracket 40 is also rotatably fitted to the cylinder 12 and is locked to the flange portion 23 of the end cap 15. The joint bracket 40 is non-rotatably coupled to the flange portion 23 using a non-rotating bolt 28. Since the lower spring receiving portion 37 is integrally formed, the same effects as in the first embodiment can be obtained. In particular, in this second embodiment, the reservoir tank 41 is separated from the joint bracket 40, so that the degree of freedom in mounting the reservoir tank 41 can be increased.
[0031]
【The invention's effect】
As described above, according to the vehicle hydraulic shock absorber according to the present invention, the structure of the joint bracket for the reservoir tank can be simplified and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view showing a part of a first embodiment of a vehicle hydraulic shock absorber according to the present invention in a cross-sectional state taken along line II of FIG.
FIG. 2 is a view taken in the direction of arrow II in FIG.
3 is an enlarged cross-sectional view of a part of FIG.
FIG. 4 is a side view showing a second embodiment of the vehicle hydraulic shock absorber according to the present invention in a cross-sectional state along the line IV-IV in FIG. 5;
FIG. 5 is a view taken in the direction of the arrow V in FIG. 4;
6 is a cross-sectional view showing a part of FIG. 4 in an enlarged manner.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Hydraulic shock absorber 11 Suspension spring 12 Cylinder 13 Piston 15 End cap 23 End cap flange part 24 Reservoir tank 25 Joint bracket 27 Notch part 28 Non-rotating bolt 33 Reservoir tank oil chamber 34 Communication path 36 Opening hole 37 Lower spring receiving part 39 Hydraulic shock absorber 40 Joint bracket 41 Reservoir tank 42 Flexible hose

Claims (5)

A hydraulic shock absorber for a vehicle in which a piston is slidably fitted inside a cylinder filled with hydraulic oil, and one end of the cylinder is closed by an end cap,
The end cap is integrally formed with a flange portion that extends outward from the outer periphery of the cylinder, and an opening hole is formed in the cylinder.
A joint bracket formed with a communication path that communicates the opening hole and the reservoir tank is rotatably fitted to the outer periphery of the cylinder and locked by the flange portion of the end cap.
A hydraulic shock absorber for a vehicle, wherein the joint bracket is non-rotatably coupled to the cylinder . 2. The vehicle hydraulic shock absorber according to claim 1, wherein the joint bracket is non-rotatably coupled to a flange portion of an end cap that closes one end of the cylinder. The joint bracket is integrally molded with the reservoir tank, a hydraulic shock absorber for a vehicle according to claim 1 or 2 communicating passage of the joint bracket communicating with the oil chamber of the reservoir tank. The joint bracket is connected to a reservoir tank via a flexible hose, the communication passage of the joint bracket according to claim 1 or 2 communicating with the oil chamber of the reservoir tank via the flexible hose Hydraulic shock absorber for vehicles. The vehicular hydraulic shock absorber according to any one of claims 1 to 4, wherein a spring receiving portion that supports a suspension spring disposed on an outer periphery of the cylinder is integrally formed on the joint bracket.

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