JP3618827B2 - Position-dependent damper - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a position-dependent oil damper for quickly dampening the motion of various vibrators. More specifically, the generated damping force in the vicinity of the neutral position of the piston is kept soft, and the vicinity of the neutral position is sandwiched therebetween. The present invention relates to a position-dependent damper suitable for use in a suspension for a seat such as a vehicle, in which the generated damping force on both sides can be automatically switched to hard.
[0002]
[Prior art]
Conventionally, as this type of position-dependent oil damper, for example, the one shown in FIG. 5 is known.
[0003]
That is, the oil damper J is divided into two hydraulic oil chambers U and L by a piston b in the cylinder a, and the pressure side rear surface opens to the piston b toward the expansion side damping force generation valve c and the hydraulic oil chamber U side. Valves d are respectively provided.
[0004]
The cylinder a cooperates with the outer shell e to form a reservoir chamber R therebetween, and a base valve f is interposed between the reservoir chamber R and the hydraulic oil chamber L.
[0005]
The base valve f is provided with a compression side damping force generation valve g and a check valve h that opens toward the hydraulic oil chamber L, corresponding to the valves on the piston b side.
[0006]
On the other hand, the bypass oil passage is formed only when the wall surface in the vicinity of the neutral position X in the cylinder a bulges outward to form a bypass oil passage i, and the piston b slides in the portion of the bypass oil passage i. The hydraulic oil chambers U and L communicate with each other through i.
[0007]
Thus, when the oil damper J receives vibration from the outside, the cylinder a and the piston b move from the illustrated relative positional relationship (normally used state 1G) over the bypass oil passage i to the hydraulic oil chamber U side ( Suppose that it is displaced to the expansion side) or the hydraulic oil chamber L side (compression side).
[0008]
Then, the opening at one end of the bypass oil passage i is closed by the piston b, and the communication between the hydraulic oil chambers U and L by the bypass oil passage i is blocked.
[0009]
As a result, the oil damper J can extend the oil in the hydraulic oil chamber U to the hydraulic oil chamber L in the piston b in accordance with the extension operation, regardless of whether the oil damper J is displaced toward the expansion side or the compression side. The side damping force generation valve c is pushed open and pushed out, and the extension side damping force is generated by the flow resistance of the oil passing through the extension side damping force generation valve c.
[0010]
At the same time, an amount of oil corresponding to the withdrawal volume of the piston rod is sucked from the reservoir chamber R into the hydraulic oil chamber L by opening the check valve h of the base valve f, and the volume in the cylinder a increases. Make up for the shortage of oil.
[0011]
On the other hand, in the compression operation, contrary to the above, the oil in the hydraulic oil chamber L is pushed out and pushed out to the hydraulic oil chamber U by pushing the pressure side rear valve d provided in the piston b, and the pressure side rear valve. The oil pressure in the hydraulic oil chamber L is increased by the flow resistance of the oil that opens d.
[0012]
In addition, in addition to the above, an amount of oil corresponding to the intrusion volume integral of the piston rod pushes the pressure side damping force generation valve g of the base valve f into the reservoir chamber R and pushes it out. The compression side damping force is generated by the flow resistance of the oil by the synergistic action with the generating valve g.
[0013]
[Problems to be solved by the invention]
As described above, in the position-dependent oil damper J in the conventional type described above, when the relative relationship between the cylinder a and the piston b is displaced from the neutral position X to either the expansion side or the compression side. In addition, the same pressure side rear valve d and pressure side damping force valve g work as in the same extension side damping force generation valve c to perform a damping action.
[0014]
As a result, the expansion side and compression side damping force characteristics associated with the expansion / contraction operation of the oil damper J are the same in both cases regardless of the displacement to the expansion side or compression side. It cannot be arbitrarily set independently according to each case.
[0015]
However, in this type of damping oil damper, when the cylinder a and the piston b are displaced to the expansion side with the static balance position being the neutral position X as a boundary from the theory of vibration, When the extension side damping force is soft and the compression side damping force is hard, and the displacement is displaced to the compression side, the extension side damping force is hard and the compression side damping force is soft. Desirable to increase.
[0016]
In that respect, the oil damper J of the conventional example in which the expansion side and the compression side damping force characteristics are the same regardless of the displacement to the expansion side or the compression side is disadvantageous in that sufficient damping action cannot be exhibited. Have
[0017]
Accordingly, an object of the present invention is to provide a novel configuration capable of independently and arbitrarily setting the extension side and compression side damping force characteristics when displaced from the static balance position to the extension side and the compression side. It is to provide a position dependent damper.
[0018]
[Means for Solving the Problems]
The above object is achieved by combining an oil damper that generates a hard damping force with a piston only during a compression operation and an oil damper that generates a hard damping force with a piston only during an extension operation in parallel. A bypass oil passage for oil flow that bypasses the piston to the cylinder side of these oil dampers extends from the neutral position of the piston toward the compression side in the former oil damper, and the latter oil damper On the other hand, it is achieved by forming each of them on the extension side.
[0019]
[Action]
That is, by configuring as described above, both oil dampers perform expansion and contraction operations in synchronization with each other in response to external vibrations, and are displaced from the 1G state, which is a normal use state, to the expansion side or the compression side. .
[0020]
When the piston is displaced on the extension side, only the piston of the former oil damper is opposed to the wall surface of the cylinder that does not have the bypass oil passage beyond the bypass oil passage. Only the piston of the oil damper faces the wall surface of the cylinder having no bypass oil passage.
[0021]
As a result, when the both oil dampers are extended while being displaced to the extension side, the former oil damper is said to be relatively displaced so that the piston faces the wall surface having no bypass oil passage on the cylinder side. Since the structure is such that a hard damping force is originally generated only during the compression operation and no damping force is generated during the extension operation, the extension operation is performed with almost no resistance.
[0022]
On the other hand, the latter oil damper, which has a structure that generates a hard damping force only during the extension operation, extends while the cylinder bypass oil passage and the piston are kept facing each other.
[0023]
Therefore, the oil damper generates a soft extension side damping force by the flow resistance of the oil flowing through the bypass oil passage without generating the original extension side damping force, and thus the former oil damper and the latter oil damper are generated. Keep the damping force generated on the extension side as a total with the damper softly.
[0024]
On the other hand, when the compression operation is performed by reversing from the above state, the latter oil damper, even in this case, performs the compression operation while keeping the bypass oil passage on the cylinder side and the piston facing each other. The soft compression side damping force is only generated in the same manner as in operation.
[0025]
However, this time, the former oil damper compresses the piston against the wall surface without the bypass oil passage on the cylinder side to generate the original compression side damping force. The former oil damper and the latter oil damper Keep the damping force generated on the compression side as a total with the damper.
[0026]
Further, when the two oil dampers are displaced from the neutral position to the compression side and extend and contract, the two oil dampers are operatively exchanged with each other, contrary to the above-described displacement to the extension side.
[0027]
That is, during the extension operation, the former oil damper originally has a structure that generates a hard damping force only during the compression operation, and the cylinder-side bypass oil passage and the piston operate opposite to each other. Therefore, the stretching operation is almost without resistance.
[0028]
On the other hand, the latter oil damper, which has a structure that generates a hard damping force only during the extension operation, is the original because the piston extends and opposes the wall surface that does not have a bypass oil passage on the cylinder side. The extension side damping force is generated, and the extension side generated damping force as a total is kept hard by the former oil damper and the latter oil damper.
[0029]
Further, when the compression operation is performed by reversing from the above state, the former oil damper, even in this case, performs the compression operation while keeping the bypass oil passage on the cylinder side and the piston facing each other. The compression operation is almost without resistance as in the operation.
[0030]
On the other hand, the latter oil damper has a structure in which almost no damping force is generated on the compression operation side, although the piston opposes the wall surface without the bypass oil passage on the cylinder side. The compression side generated damping force by the former oil damper and the latter oil damper is totally soft.
[0031]
Thus, when both oil dampers are combined in parallel to form a set, when the static balance position is displaced to the expansion side, the compression side has a hard damping force characteristic only on the compression side and the compression side. When it is displaced, the damping force characteristic is hard only on the extension side and soft on the compression side.
[0032]
The compression side damping force characteristic and the extension side damping force characteristic when displaced to the expansion side or the compression side are the position of the bypass oil passage provided on the cylinder side of both oil dampers, the compression side generated damping force and the extension force in each oil damper. By arbitrarily selecting the side generated damping force, it is set without any influence on the other side.
[0033]
Therefore, by setting the position of the bypass oil passage and the compression side and extension side generated damping forces in each oil damper independently, a position-dependent damper having a more excellent damping action can be obtained.
[0034]
【Example】
Hereinafter, preferred embodiments of the present invention will be described.
[0035]
FIG. 1 and FIG. 2 show oil dampers A and B that are used as a set in parallel with each other in the present invention.
[0036]
The oil damper A in FIG. 1 has a cylinder 1 and an outer shell 2 that surrounds the cylinder 1 and is arranged concentrically. The cylinder 1 and the upper end of the outer shell 2 enclose a bearing 3 and a seal 4. It is sealed by a seal case 5.
[0037]
The lower end of the outer shell 2 is sealed with a bottom cap 6, and a base valve 7 is fitted on the lower end of the cylinder 1. The cylinder 1 has a base valve 7 fitted on the lower end. It is pressed against the inner surface of the bottom cap 6 through the centering.
[0038]
Thereby, the outer shell 2 defines a reservoir chamber R between the outer shell 2 and the cylinder 1, and the reservoir chamber R communicates with the lower portion of the cylinder 1 through the base valve 7.
[0039]
A piston 8 is slidably inserted into the cylinder 1, and the piston 8 divides the cylinder 1 into an upper hydraulic oil chamber U and a lower hydraulic oil chamber L.
[0040]
A piston rod 9 extending upward from the piston 8 passes through the bearing 3, the seal 4, and the seal case 5 and protrudes to the outside. The piston rod 9 is mounted between the upper end of the piston rod 9 and the two members that vibrate through the bottom cap 6. The
[0041]
The piston 8 has an extension side port 10 and a pressure side port 11 penetrating in the axial direction. A check valve 12 that opens toward the lower hydraulic oil chamber L side is provided at the lower end of the extension side port 10. 11 is provided with a pressure side rear valve 14 at the upper end thereof.
[0042]
Similar to the piston 8, the base valve 7 is also provided with an extending side port 16 and a pressure side port 17 penetrating in the axial direction, and an upper end of the extending side port 16 is opened toward the lower hydraulic oil chamber L side. A valve 18 and a compression side damping force generation valve 19 are disposed at the lower end of the compression side port 17.
[0043]
Thus, the oil damper A has the pressure side rear valve 14 and the pressure side damping force generating valve 19 only during the compression operation in which the pressure side rear valve 14 on the piston 8 side and the pressure side damping force generating valve 19 on the base valve 7 side act. It works as an oil damper that generates a hard damping force through the cooperative action.
[0044]
On the other hand, the other oil damper B used in combination with the oil damper A is different from the oil damper A described so far in that the position of the bypass oil passage 22 provided in the cylinder 1 and the extension of the piston 8 are increased. The type of each valve arranged in the side and pressure side ports 10 and 11 is different, and the other configuration is completely the same.
[0045]
That is, in the oil damper B, as shown in FIG. 2, the bypass oil passage 22 formed by the slit 20 and the cover 21 is formed from the vicinity of the neutral position X to the extension side with respect to the cylinder 1. It is.
[0046]
An extension side damping force generation valve 13 is provided at the lower end of the extension side port 10 of the piston 8 instead of the check valve 12, and an upper hydraulic oil chamber is provided at the upper end of the pressure side port 11 instead of the pressure side rear valve 14. A check valve 15 that opens toward the U side is provided.
[0047]
As a result, the oil damper B generates a hard damping force by the expansion side damping force generation valve 13 on the piston 8 side during the extension operation, and a soft side by the compression side damping force generation valve 19 on the base valve 7 side during the compression operation. In contrast to the oil damper A described above, it acts as an oil damper that generates a hard damping force only during the extension operation.
[0048]
Next, the operation when these oil dampers A and B are used in combination with each other as a set will be described.
[0049]
(1) During expansion / contraction operation near the neutral position X, which is a static balance position.
[0050]
During the extension operation, the oil damper A performs the extension operation while flowing the oil in the upper hydraulic oil chamber U together with the bypass oil passage 22 from the extension port 10 of the piston 8 to the lower hydraulic oil chamber L by opening the check valve 12. To do.
[0051]
On the other hand, the oil damper B extends and synchronizes with the oil damper A while flowing the oil in the upper hydraulic oil chamber U from only the bypass oil passage 22 toward the lower hydraulic oil chamber L.
[0052]
In addition to these, the oil dampers A and B provide the base valve with a quantity of oil corresponding to the withdrawal volume of the piston rod 9 from the reservoir chamber R as the piston rod 9 is withdrawn from the cylinder 1. 7 check valve 18 is opened and sucked into the lower hydraulic oil chamber L, and the shortage of oil generated in the cylinder 1 at that time is compensated.
[0053]
As a result, the oil damper A generates a soft damping force due to the flow resistance of the oil passing through the expansion side port 10 of the piston 8, and the oil damper B operates to extend without generating any damping force. Keep the total extension side damping force in a soft state.
[0054]
On the other hand, during the compression operation, contrary to the above, the oil damper A performs the compression operation while flowing the oil in the lower hydraulic oil chamber L only from the bypass oil passage 22 to the upper hydraulic oil chamber U. The oil damper B compresses the oil in the lower hydraulic oil chamber L in synchronism with each other while opening the check valve 15 from the pressure side port 11 of the piston 8 together with the bypass oil passage 22 and flowing to the upper hydraulic oil chamber U. To do.
[0055]
Together with these, both oil dampers A and B push open the compression side damping force generating valve 19 of the base valve 7 from the lower hydraulic oil chamber L by opening an amount of oil corresponding to the infiltration volume of the piston rod 9 respectively. The oil is pushed out into the reservoir chamber R, and the excess oil generated in the cylinder 1 at that time is compensated.
[0056]
Thereby, both the oil dampers A and B generate a soft damping force mainly by the flow resistance of the oil passing through the compression side damping force generation valve 19 of the base valve 7, and keep the compression side damping force in a soft state as a total. It will be compressed.
[0057]
Thus, at the time of expansion / contraction operation in the vicinity of the neutral position X, both the expansion side and compression side damping force become soft damping force characteristics.
[0058]
(2) During expansion / contraction when the neutral position X is displaced to the extension side.
[0059]
When the oil dampers A and B are synchronously displaced to the extension side, the piston 8 of one oil damper A is merely displaced relative to the wall surface without the bypass oil passage 22 on the cylinder 1 side, and the other The oil damper B still expands and contracts while maintaining the state where the bypass oil passage 22 on the cylinder 1 side and the piston 8 face each other.
[0060]
As a result, during the extension operation, the oil damper A opens the check valve 12 from the extension side port 10 of the piston 8 through the oil in the upper hydraulic oil chamber U, and the oil damper B passes through the bypass oil passage 22. Pour into the lower hydraulic oil chamber L.
[0061]
As a result, the oil dampers A and B extend while maintaining the total extension side damping force in a soft state by the flow resistance of the oil passing through the bypass oil passage 22 on the oil damper B side.
[0062]
In addition to the above, the oil dampers A and B open the check valve 18 provided in the expansion side port 16 of the base valve 7 from the reservoir chamber R with an amount of oil corresponding to the withdrawal volume of the piston rod 9 to operate in the lower part. Suck into the oil chamber L to compensate for the shortage of oil in the cylinder 1.
[0063]
On the other hand, when the compression operation is shifted from the above state, the oil damper A pushes and opens the pressure side rear valve 14 from the pressure side port 11 of the piston 8 and pushes the oil in the lower hydraulic oil chamber L to the upper hydraulic oil chamber U. Compressing operation.
[0064]
The oil damper B is compressed by flowing the oil in the lower hydraulic oil chamber L only from the bypass oil passage 22 to the upper hydraulic oil chamber U while the bypass oil passage 22 on the cylinder 1 side and the piston 8 still face each other. .
[0065]
In addition to these, the oil dampers A and B push open the pressure side damping force generation valve 19 of the base valve 7 from the lower hydraulic oil chamber L by opening an amount of oil corresponding to the infiltration volume of the piston rod 9 into the reservoir chamber. Extrude to R to compensate for excess oil in cylinder 1.
[0066]
As a result, during the compression operation, the oil damper A generates a hard damping force by the cooperative action of the pressure side rear valve 14 and the pressure side damping force generation valve 19 of the base valve 7, and the oil damper B is the base valve. 7 generates a soft compression damping force, and both oil dampers A and B perform a compression operation while keeping the compression compression damping force in a hard state as a total.
[0067]
Thus, when it is displaced to the extension side, the extension side has soft damping characteristics and the compression side has hard characteristics.
[0068]
(3) During expansion / contraction operation when the neutral position X is displaced to the compression side.
[0069]
When the oil dampers A and B are synchronously displaced to the compression side, the piston 8 of the oil damper A is opposed to the bypass oil passage 22 on the cylinder 1 side and performs relative displacement, contrary to the above. The piston 8 of the other oil damper B is displaced relative to the wall surface without the bypass oil passage 22 on the cylinder 1 side.
[0070]
Thus, during the compression operation, the oil dampers A and B push the oil in the lower hydraulic oil chamber L from the compression side damping force generation valve 19 of the base valve 7 to the reservoir chamber R, and perform oil volume compensation. In addition, the oil damper A opens the check valve 15 from the bypass oil passage 22 and the oil damper B from the pressure side port 11 of the piston 8 through the oil in the lower hydraulic oil chamber L to the upper hydraulic oil chamber U.
[0071]
Thus, both the oil dampers A and B perform a compression operation while maintaining the compression side damping force in a soft state mainly by the flow resistance of the oil by the compression side damping force generation valve 19 of the base valve 7.
[0072]
On the other hand, when the operation is extended from the above state, the oil damper A causes the bypass oil passage 22 to pass the oil in the upper hydraulic oil chamber U while the bypass oil passage 22 on the cylinder 1 side and the piston 8 still face each other. To extend toward the lower hydraulic oil chamber L.
[0073]
The oil damper B is extended while pushing the extension side damping force generation valve 13 from the extension side port 10 of the piston 8 and pushing the oil in the upper hydraulic oil chamber U to the lower hydraulic oil chamber L.
[0074]
In addition to these, the oil dampers A and B open the check valve 18 provided with an amount of oil corresponding to the withdrawal volume of the piston rod 9 from the reservoir chamber R to the extension side port 16 of the base valve 7 to open the lower part. The oil is sucked into the hydraulic oil chamber L and the shortage of oil in the cylinder 1 is compensated.
[0075]
As a result, during the extension operation, the oil damper A generates almost no damping force, and only the oil damper B generates a hard damping force by the extension side damping force generation valve 13 of the piston 8, and both oil dampers. A and B perform an extension operation while maintaining a total extension side damping force in a hard state.
[0076]
As a result, when it is displaced to the extension side, contrary to the displacement to the compression side, the extension side has hard damping characteristics and the compression side has soft damping force characteristics.
[0077]
Thus, the compression side damping force characteristic and the extension side damping force characteristic when displaced to the expansion side or the compression side are the position of the bypass oil passage 22 provided in the cylinder 1 of the oil dampers A and B, and the pressure side of the piston 8 in the oil damper A. It is determined by the respective valve characteristics of the back side valve 14 and the compression side damping force generation valve 19 of the base valve 7 and the extension side damping force generation valve 13 of the piston 8 in the oil damper B.
[0078]
Moreover, the installation positions of the bypass oil passages 22 and the valve characteristics of the valves 13, 14 and 19 can be set without any influence on each other.
[0079]
Accordingly, the installation positions of the bypass oil passages 22 and the valve characteristics of the extension side damping force generation valve 13, the pressure side rear valve 14, and the pressure side damping force generation valve 19 are set independently of each other. A position-dependent damper having a damping action can be obtained.
[0080]
In the oil dampers A and B shown in FIGS. 1 and 2 described so far, the bypass oil passage 22 is constituted by the slit 20 formed in the cylinder 1 and the cover 21 covering the same. Of course, the upper and lower oil holes 1 may be replaced with each other, or the wall surface of the cylinder 1 may be formed by bulging outward as in the conventional example of FIG.
[0081]
However, in the configuration of the bypass oil passage 22, the means for bulging the wall surface of the cylinder 1 outward is troublesome to make, and the slit 20 or the like as shown in FIGS. The means using the oil hole and the cover 21 may cause a deviation in the roundness of the cylinder 1 due to the attachment of the cover 21, and may hinder the movement of the piston 8.
[0082]
The embodiment shown in FIGS. 3 and 4 is configured in consideration of these points. In this embodiment, guides 24 having a seal 23 on the inner peripheral surface side are fitted to the upper and lower ends of the cover 21. The cover 21 is held in a predetermined position by a spring 25 while the seal 23 of the guide 24 is kept oiltight with the cylinder 1.
[0083]
According to this, not only the processing of the cover 21 is facilitated but also the circularity of the cylinder 1 is not affected even when the cover 21 is attached, so that the operability as an oil damper is kept good. be able to.
[0084]
【The invention's effect】
As described above, according to the present invention, the positions of the bypass oil passages of the individual oil dampers used as a set, the compression side damping force characteristics of one oil damper and the extension side damping of the other oil damper are related thereto. By appropriately selecting the force characteristics, the damping force characteristics when these oil dampers are displaced to the expansion side and compression side must be set independently without affecting each other. Can do.
[0085]
Thus, the expansion side soft and compression side hard damping force characteristics are generated at the time of displacement to the expansion side, and conversely the compression side soft damping force characteristic is generated at the expansion side hard and at the time of displacement to the compression side. An excellent position-dependent damper can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional front view showing one oil damper of a position dependent damper according to an embodiment of the present invention.
FIG. 2 is a longitudinal front view showing the other oil damper used in combination with the oil damper same as above.
FIG. 3 is a longitudinal sectional front view showing one oil damper of a position-dependent damper according to another embodiment of the present invention.
FIG. 4 is a longitudinal front view showing the other oil damper used in combination with the above oil damper.
FIG. 5 is a longitudinal front view showing a position-dependent damper as a conventional example.
[Explanation of symbols]
1 Cylinder 2 Outer shell 7 Base valve 8 Piston 12, 15, 18 Check valve 13 Extension side damping force generation valve 14 Pressure side rear valve 19 Pressure side damping force generation valve 20 Slit 21 Cover 22 Bypass oil path A, B Oil damper L Lower operation Oil chamber R Reservoir chamber U Upper hydraulic oil chamber X Neutral position

Claims (1)

An oil damper that generates a hard damping force with a piston only during compression operation and an oil damper that generates a hard damping force with a piston only during extension operation are combined in parallel. For the former oil damper, the bypass oil passage for bypassing the piston is extended from the vicinity of the neutral position of the piston to the compression side, and to the opposite side to the latter oil damper. A position-dependent damper, characterized by being formed respectively.

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