JP3573170B2 - Damping force adjustment structure - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an improvement in a damping force adjusting structure suitable for use in a hydraulic shock absorber mounted on a motorcycle, a special bicycle, or the like.
[0002]
[Prior art]
In general, a hydraulic shock absorber mounted on a vehicle such as a motorcycle is configured so that a damping force of a predetermined magnitude is generated by a damping force generating section when the telescopic operation is performed. In many cases, the damping force generated by the damping force generator is adjusted by the damping force adjuster so that the damping force becomes a damping force according to the running conditions of the vehicle.
[0003]
In particular, in the case of a hydraulic shock absorber mounted on an off-road motorcycle or a motocross special bicycle, the damping force on the pressure side generated by the damping force generation unit can be adjusted by the damping force adjustment unit. In many cases, the hydraulic shock absorber is configured as shown in FIG. 2, for example.
[0004]
That is, the hydraulic shock absorber is externally operated in an oil passage L communicating the pressure side oil chamber A1 in the damper body D and the oil chamber A2 in the so-called reservoir tank R as a so-called reservoir. A damping force adjusting structure having a damping force adjusting unit 1 capable of adjusting the level of a compression damping force generated by a damping force generating unit (not shown) is employed.
[0005]
As shown in FIG. 3, the damping force adjusting section 1 constituting the damping force adjusting structure connects the oil passage L to an oil passage portion L1 on the pressure side oil chamber A1 side and an oil passage portion L2 on the reservoir tank R side. An adjusting rod 10 is provided in a chamber A3 formed by partially expanding so as to be divided and rotatable by an external operation.
[0006]
The adjusting rod 10 has a pressure-side check valve 11 for preventing the flow of the hydraulic oil from the oil passage portion L1 into the oil passage portion L2, and the flow of the hydraulic oil from the oil passage portion L1 to the oil passage portion L2 side. And a plurality of orifices 13 and 14 having different diameters selectively facing the oil passage portion L2.
[0007]
In this conventional example, the adjusting rod 10 is disposed so as to occupy the chamber A3, and its outer periphery is slidably contacted with the inner periphery of the chamber A3, so that the oil passage L is shut off. Therefore, the pressure-side check valve 11 is disposed on the inner periphery of the distal end, which is the left end in the drawing, of the adjustment rod 10 so as to face the oil passage portion L1.
[0008]
The pressure-side check valve 11 is configured to open and close the expansion-side port 15 opened by the adjusting rod 10 and communicating with the oil passage portion L2 from the oil passage portion L1 under the urging of the return spring 16. It is arranged.
[0009]
Further, the extension side port 15 communicates with an annular groove 17 formed on the outer periphery of the adjusting rod 10, and the annular groove 17 is provided with an orifice 13, 14 provided in the flow path 12, which selectively opposes oil. It is set so as to communicate with the road portion L2.
[0010]
In this conventional example, the adjusting rod 10 has an auxiliary orifice 18 that connects the flow path 12 and the extension side port 15.
[0011]
Therefore, according to the hydraulic shock absorber having the above-described damping force adjusting section 1, that is, according to the conventional damping force adjusting structure, the adjusting rod 10 is rotated by an external operation to provide the orifices 13 and When any one of the orifices 14 faces the oil passage portion L2, the flow of the hydraulic oil according to the diameter of the selected orifices 13 and 14 is ensured, and the compression-side damping force generated when the damper main body D is compressed is high or low. Adjusted.
[0012]
When both of the orifices 13 and 14 are no longer opposed to the oil passage portion L2 due to an operation error of the adjustment rod 10 or the like, the pressure side of the damper main body D via the auxiliary orifice 18 that bypasses the orifices 13 and 14. The hydraulic oil from the oil chamber A1 can flow into the oil chamber A2 of the reservoir tank R.
[0013]
As a result, even when the damper main body D operates on the compression side while the orifices 13 and 14 do not function, the oil lock phenomenon does not occur in the compression side oil chamber A1 in the damper main body D, and oil leakage or leakage at the seal portion is prevented. A situation such as damage to the damper body D itself can be avoided in advance.
[0014]
[Problems to be solved by the invention]
However, the following disadvantages have been pointed out in the conventional damping force adjusting structure described above.
[0015]
That is, in the above-mentioned conventional damping force adjusting structure, the damping force generated in the damper main body D is adjusted by selecting the orifices 13 and 14, so that the damper main body D performs the compression operation at a high speed. In this case, because of the so-called orifice characteristic, the oil pressure in the pressure side oil chamber A1 in the damper main body D becomes abnormally high, and there still remains fears such as oil leakage at the seal portion and damage to the damper main body D itself.
[0016]
Conversely, when the damper body D performs a compression operation at a low speed including a very low speed, the orifice having a small diameter, that is, in the illustrated example, even if the orifice 14 is selected, the orifice characteristic causes a variable width. Is small, and the adjustment width is large, that is, it cannot be adjusted effectively.
[0017]
Further, in the above-described conventional damping force adjustment structure, when neither of the orifices 13 and 14 is opposed to the oil passage portion L2 due to an operation error or the like with respect to the adjustment rod 10, the pressure side oil chamber A1 in the damper body D. An auxiliary orifice 18 that bypasses the orifices 13 and 14 is provided in order to avoid inconveniences such as an oil lock phenomenon, oil leakage at the seal portion, and damage to the damper body D itself.
[0018]
Therefore, when the damper body D performs the compression operation at a low speed including a very low speed, since the auxiliary orifice 18 is so-called active, even if the orifice 14 having a particularly small diameter is selected, a desired damping force adjusting effect can be obtained. You will not get it.
[0019]
When the auxiliary orifice 18 is set for low speed operation, when the damper main body D performs a high-speed compression operation in a state where none of the orifices 13 and 14 function due to an operation error or the like, the above-mentioned pressure side oil chamber A1 has Due to the abnormally high pressure, oil leakage at the seal portion, damage to the damper body D itself, and the like are likely to occur.
[0020]
As a result, even if the hydraulic shock absorber using the above-described damping force adjustment structure is mounted on a motorcycle of an off-road specification or a special bicycle of a motocross specification, it is not possible to realize a preferable adjustment of the compression side damping force.
[0021]
The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the occurrence of oil leakage at the seal portion and damage to the damper body even if an operation error occurs in the damping force adjusting portion. Of course, it is possible to effectively control the compression-side damping force by a predetermined operation on the damping force adjusting unit, and the hydraulic shock absorber mounted on an off-road motorcycle or a motocross special bicycle. An object of the present invention is to provide a damping force adjusting structure that is optimal for use in a vessel.
[0022]
[Means for Solving the Problems]
In order to achieve the above-described object, a basic configuration of the present invention is configured such that an oil passage connecting a pressure side oil chamber in a damper main body and an oil chamber in a reservoir tank is partially expanded in diameter. A damping force adjustment unit housed in the chamber and capable of adjusting the compression-side damping force generated during the compression operation of the damper body by an external operation, wherein the damping force adjustment unit is disposed in the chamber and operated externally. An adjustment rod rotatable by the pressure-side oil chamber, the adjustment rod having a pressure-side check valve for preventing the flow of hydraulic oil from the pressure-side oil chamber into the oil chamber, and the pressure-side oil chamber being provided at a shaft portion thereof. Damping force adjustment having a flow path that allows the flow of hydraulic oil from the oil chamber into the oil chamber, and the flow path has a plurality of orifices of different diameters selectively facing the oil chamber side. In the structure, the adjustment rod is placed on the outer circumference of the A pressure-side check valve for preventing the hydraulic oil from flowing into the oil chamber, and the hydraulic oil from the pressure-side oil chamber flowing into the oil chamber at the time of its opening operation, which retreats against an urging force from the rear side. A pressure-side relief valve which allows the pressure-side relief valve to be closed when the pressure-side relief valve is seated on the back surface of a seat member that detaches and seats the pressure-side check valve with a biasing force from the back side. At the same time, it is assumed that the flow path area formed on the back side of the pressure side relief valve at the time of the opening operation is limited depending on the retreat amount.
[0023]
More specifically, the pressure-side relief valve forms a passage that allows the flow of hydraulic oil on its inner peripheral side, and has a partition wall part whose outer periphery is in sliding contact with the inner periphery of the chamber. It is assumed that the partition is formed so as to limit the flow path area by moving the partition.
[0024]
[Action]
Therefore, when one of the orifices is selected by the accurate turning operation of the adjusting rod in the damping force adjusting section, the hydraulic oil from the pressure side oil chamber in the damper main body is applied to the adjusting rod during the compression operation of the damper main body. The fluid flows into the oil chamber in the reservoir tank through the formed flow path and any one of the orifices communicating with the flow path.
[0025]
At this time, the flow rate of the hydraulic oil is set to a flow rate corresponding to the diameter of the selected orifice, and the pressure-side damping force generated in the damper main body is adjusted as far as it is.
[0026]
Further, when the adjusting rod in the damping force adjusting section is not accurately rotated and none of the orifices is selected, the hydraulic oil from the pressure side oil chamber opens the pressure side relief valve at the time of the compression operation of the damper body. It flows into the oil chamber in the reservoir tank.
[0027]
At this time, the pressure side relief valve blocks the flow of the hydraulic oil on the outer peripheral side to allow the flow of the hydraulic oil on the inner peripheral side, while the hydraulic oil via the inner peripheral side is supplied to the oil chamber. When flowing in, the flow passage area is limited according to the retreat amount of the pressure side relief valve.
[0028]
As a result, even if none of the orifices is selected, the compression-side oil chamber in the damper body does not cause the oil lock phenomenon or the abnormally high pressure phenomenon during the compression operation of the damper body at a high speed.
[0029]
On the other hand, unrestricted flow of hydraulic oil from the pressure side oil chamber to the oil chamber due to the opening operation of the pressure side relief valve is suppressed.
[0030]
As a result, even when the orifice does not function, the compression damping force is adjusted at the time of the compression operation of the damper body at a high speed.
[0031]
And, even when the orifice having a small diameter is selected by the accurate turning operation of the adjusting rod, the compression side relief valve performs a predetermined opening operation when the damper body performs the compression operation at a high speed. Thus, an oil lock phenomenon and an abnormally high pressure phenomenon are not caused in the pressure side oil chamber.
[0032]
Hydraulic oil that has flowed into the oil chamber in the reservoir tank passes through the inner peripheral side of the pressure side relief valve and opens the pressure side check valve when the damper body elongates, causing the hydraulic oil in the damper body to run short. It is returned to the compression oil chamber.
[0033]
【Example】
Hereinafter, the present invention will be described based on the illustrated embodiment, but the damping force adjusting structure according to the present invention is also not shown, but similarly to the conventional example shown in FIG. The pressure side damping which is accommodated in a chamber A3 formed by partially expanding an oil passage L communicating the oil passage A1 and an oil chamber A2 in the reservoir tank R and which is generated when the damper body D is compressed by an external operation. It has a damping force adjusting section 1 capable of adjusting the level of force.
[0034]
Although not shown, the damper main body D has a piston portion that generates a predetermined compression-side damping force during its compression operation.
[0035]
As shown in FIG. 1, the damping force adjusting section 1 includes an adjusting rod 10 which is disposed in the chamber A3 and is rotatable by an external operation. A pressure-side check valve 11 and a pressure-side relief valve 20 are interposed on the outer periphery of the spigot portion 10a on the left end side.
[0036]
Further, the adjusting rod 10 has a flow path 12 in the shaft core portion on the distal end side thereof, which allows the hydraulic oil from the pressure side oil chamber A1 to flow toward the oil chamber A2. The flow path 12 has a plurality of orifices 13 and 14 having different diameters selectively facing the oil chamber A2 side.
[0037]
The adjusting rod 10 is set so as not to be dropped from a predetermined position, that is, from the inside of the chamber A3, by the fixing nut 2 screwed to the housing portion H forming the chamber A3.
[0038]
Further, the adjusting rod 10 has a flange portion 10b protruding at an appropriate length on the outer peripheral side at a base end side on the right side in the drawing, and the adjusting rod 10 is disposed in the chamber A3. In this case, the flange portion 10b is brought into contact with a step H1 formed on the housing portion H to fix the flange portion 10b at a predetermined position.
[0039]
Further, also in this embodiment, since the adjusting rod 10 is disposed in the chamber A3, as a result, the oil passage L is connected to the oil passage portion L1 on the pressure side oil chamber A1 side and the oil chamber A2. And an oil passage portion L2 on the side.
[0040]
The adjustment rod 10 has a tool insertion groove 10c at its base end, which is the right end in the figure, for enabling the adjustment rod 10 to be rotated by an external operation.
[0041]
The pressure-side check valve 11 prevents the hydraulic oil from flowing from the pressure-side oil chamber A1 into the oil chamber A2. In this embodiment, the valve is provided on the outer periphery of the spigot portion 10a. It is arranged so as to be interposed in the seat member 21.
[0042]
The pressure side check valve 11 closes a communication hole 21a opened in the valve seat member 21 so as to be opened and closed under the urging of the return spring 16 from the pressure side oil chamber A1, that is, the oil passage portion L1 side. I have.
[0043]
The valve seat member 21 is disposed between the pressure-side check valve 11 and the pressure-side relief valve 20, and is in contact with a step 10 d formed on the outer periphery on the distal end side of the adjustment rod 10. It is fixed by screwing the nut 22 to the tip thread portion 10e.
[0044]
Further, the valve seat member 21 has a gap between the outer periphery thereof and the inner periphery of the storage chamber A3, and allows the passage of hydraulic oil.
[0045]
The pressure-side relief valve 20 is configured to move the hydraulic oil from the pressure-side oil chamber A1 to the oil chamber A2 at the time of its opening operation, which retreats against the urging force from the rear side, that is, the urging force of the urging spring 23. It is set to allow inflow.
[0046]
The pressure side relief valve 20 is closed when it is seated on the back surface of the seat member 21 by the urging force from the rear side, and is formed on the back side of the pressure side relief valve 20 when it retreats. The flow path area is set to be limited depending on the receding amount.
[0047]
That is, in this embodiment, the pressure side relief valve 20 has a flat annular valve body portion 20a which is seated on the seat member 21 in a state where the communication hole 21a is not closed. 20a, the partition wall 20b is formed in a cylindrical shape, the outer periphery of which is in sliding contact with the inner periphery of the chamber A3, and further has an inner peripheral side, particularly, an inner periphery of the valve body portion 20a. It is assumed that there is a gap between the outer periphery of the spigot portion 10a and the passage of hydraulic oil.
[0048]
Then, the flow path area is secured between the base end of the partition wall portion 20b, which is the right end in the drawing, and a portion facing the base end, that is, the sliding contact portion 10f of the adjustment rod 10 to the inner periphery of the chamber A3. And
[0049]
Therefore, the pressure side relief valve 20 is opened when it overcomes the urging force of the urging spring 23 and retreats away from the seat member 21, and the hydraulic oil from the pressure side oil chamber A 1 is opened. Crosses the outer periphery of the valve seat member 21 and the inner periphery of the valve body portion 20a, and allows the gas to flow into the oil chamber A2 through the space between the partition wall portion 20b and the sliding contact portion 10f. Will be.
[0050]
At this time, the flow rate of the hydraulic oil passing between the seat member 21 and the valve body 20a is determined according to the retreat amount of the pressure side relief valve 20, while the flow rate of the hydraulic oil is determined according to the retreat amount of the pressure side relief valve 20. The flow path area formed between the partition wall portion 20b and the sliding contact portion 10f is limited by the movement of the partition wall portion 20b, and the flow rate of the hydraulic oil passing therethrough is regulated.
[0051]
In the damping force adjusting structure according to this embodiment having the damping force adjusting portion 1 formed as described above, one of the orifices 13 and 14 is selected by the accurate turning operation of the adjusting rod 10. At the time of the compression operation of the damper main body D, the hydraulic oil from the pressure side oil chamber A1 in the damper main body D passes through the flow path 12 formed in the adjustment rod 10 and one of the orifices 13 and 14 communicating with the flow path 12. Through the oil chamber A2 in the reservoir tank R.
[0052]
At this time, the flow rate of the hydraulic oil is set to a flow rate corresponding to the diameter of the selected orifices 13 and 14, and the pressure-side damping force generated in the damper body D is adjusted as far as it is.
[0053]
Also, when the adjusting rod 10 in the damping force adjusting section 1 is not accurately rotated and neither of the orifices 13 and 14 is selected, the hydraulic oil from the pressure side oil chamber A1 is discharged during the compression operation of the damper body D. The pressure relief valve 20 is opened to flow into the oil chamber A2 in the reservoir tank R.
[0054]
At this time, the pressure side relief valve 20 prevents the flow of the hydraulic oil on the outer peripheral side to allow the flow of the hydraulic oil on the inner peripheral side, while the hydraulic oil through the inner peripheral side is supplied to the oil chamber. When flowing into A2, the flow path area is limited according to the retreat amount of the pressure side relief valve 20.
[0055]
As a result, even if neither of the orifices 13 and 14 is selected, not only the oil lock phenomenon but also the abnormal high pressure phenomenon occurs in the pressure side oil chamber A1 in the damper body D during the compression operation of the damper body D at a high speed. Will not be invited.
[0056]
On the other hand, at the time of the opening operation of the compression side relief valve 20, the operation oil from the compression side oil chamber A1 is suppressed from flowing into the oil chamber A2 without restriction.
[0057]
As a result, even when the orifices 13 and 14 do not function, the compression damping force is adjusted at the time of the compression operation of the damper main body D at a high speed.
[0058]
Then, even when the orifice 14 is selected, for example, when the orifice 14 is selected, the compression side relief valve 20 performs a compression operation at a high speed even when the orifice 14 is selected. Means that a predetermined opening operation is performed and the oil lock phenomenon and the abnormally high pressure phenomenon are not caused in the pressure side oil chamber A1.
[0059]
The hydraulic oil that has flowed into the oil chamber A2 in the reservoir tank R passes through the inner peripheral side of the pressure-side relief valve 20 and opens the pressure-side check valve 11 when the damper body D extends, so that the hydraulic oil runs short. It is returned to the pressure side oil chamber A1 in the damper main body D which tends to.
[0060]
As described above, the damping force adjusting portion 1 constituting the damping force adjusting structure according to the present invention is in the passage L communicating the pressure side oil chamber A1 in the damper body D and the oil chamber A2 in the reservoir tank R, that is, Although the damper body D and the reservoir tank R are separated from the damper body D, the damper body D is disposed in the housing portion H. However, in view of the intention of the present invention, the damper body D is set as follows. good.
[0061]
That is, although not shown, the reservoir tank R is formed in a cylindrical shape on the outer periphery of the damper main body D, and therefore, the damping force adjusting section 1 is disposed at the bottom portion or the base valve portion, which is the lower end of the damper main body D, The adjustment rod 10 may be set to be rotatable by an external operation.
[0062]
Also in this case, it is needless to say that the same operation and effect as in the above-described embodiment can be expected.
[0063]
【The invention's effect】
As described above, according to the present invention, while the damping force adjusting section has the orifices having different diameters that can be selected, the damping force adjusting section has the pressure-side relief valve. Therefore, the compression-side damping force generated in the damper body by selecting the orifice. In addition to being able to adjust the height of the seal, even when the damper main body performs the compression operation at a high speed, the operation of the pressure side relief valve can prevent the abnormally high pressure in the pressure side oil chamber in the damper main body beforehand, so that the seal portion can be prevented. In such a case, there is no need to worry about oil leakage or damage to the damper body itself.
[0064]
Then, even when none of the orifices is functioning due to an operation error with respect to the adjustment rod, etc., since the pressure side relief valve is provided, the oil lock phenomenon does not occur in the pressure side oil chamber in the damper body, and therefore, Even in the case of this operation error, there is no need to worry about oil leakage at the seal portion or damage to the damper body itself.
[0065]
Further, according to the present invention, since the auxiliary orifice for preventing the oil lock phenomenon from being caused in the damper body when the operation of the adjustment rod is erroneous is not configured, the orifice having a small diameter is selected by rotating the adjustment rod. Even when adjusting the damping force when the damper body performs the compression operation at a low speed including a very low speed, the adjustment is realized more effectively.
[0066]
As a result, according to the present invention, when the hydraulic shock absorber using the damping force adjusting structure having the damping force adjusting section is mounted on an off-road motorcycle or a motocross special bicycle, the damping force is reduced. Even if there is an operation error in the adjustment unit, it is possible to prevent oil leaks in the seal unit and damage to the damper body, etc., as well as to perform effective control for adjusting the compression-side damping force by a predetermined operation on the damping force adjustment unit. This has the advantage that it is possible to achieve a preferred adjustment of the compression damping force.
[Brief description of the drawings]
FIG. 1 is a partially enlarged cross-sectional view showing a damping force adjusting section constituting a damping force adjusting structure according to an embodiment of the present invention.
FIG. 2 is an elevational view showing a hydraulic shock absorber having a damping force adjusting structure as a conventional example, partially cut away.
FIG. 3 is a partial cross-sectional view illustrating a damping force adjustment unit included in the damping force adjustment structure of FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Damping force adjustment part 10 Adjustment rod 11 Pressure side check valve 12 Flow path 13, 14 Orifice 20 Pressure side relief valve 20b Partition wall 21 Sheet member A1 Pressure side oil chamber A2 Oil chamber A3 Storage chamber D Damper body L Oil path R Reservoir tank

Claims (2)

A pressure side generated when a compression operation of the damper body is performed by an external operation and housed in a chamber formed by partially expanding an oil path communicating the pressure side oil chamber in the damper body and the oil chamber in the reservoir tank. It has a damping force adjusting portion capable of adjusting the damping force, and the damping force adjusting portion has an adjusting rod disposed in the chamber and rotatable by an external operation. It has a pressure side check valve for preventing the flow of hydraulic oil from the pressure side oil chamber into the oil chamber, and has a flow passage in its shaft core that allows the flow of hydraulic oil from the pressure side oil chamber into the oil chamber. And, in the damping force adjusting structure in which the flow path has a plurality of orifices having different diameters selectively facing the oil chamber side, an adjusting rod is provided on the outer periphery of the front end spigot portion from the pressure side oil chamber. A pressure-side check bar that prevents hydraulic oil from flowing into the oil chamber And a pressure relief valve that allows the hydraulic oil from the pressure side oil chamber to flow into the oil chamber at the time of its opening operation, which retreats against the urging force from the rear side, and The compression-side relief valve is closed when the compression-side relief valve is seated on the back side of the seat member that detaches and seats the compression-side check valve by the urging force from the rear side, and is formed on the rear side of the compression-side relief valve when the compression-side check valve is opened. Damping force adjustment structure formed to limit the flow path area depending on the amount of retreat The pressure side relief valve has a passage on the inner peripheral side thereof that allows the flow of hydraulic oil, and has a partition wall whose outer periphery is in sliding contact with the inner periphery of the chamber. 2. The damping force adjusting structure according to claim 1, wherein the damping force adjusting structure is formed so as to limit the flow passage area.

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