JP2013060960A - Damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the shortage of a working fluid even if using an aqueous fluid as the working fluid, related to the improvement of a damper.SOLUTION: In the damper D comprising a cylinder 1 and an outer cylinder 2 forming a reservoir R between the cylinder 1 and itself, and in which the reservoir R is composed of an in-reservoir liquid chamber R1, and an in-reservoir air chamber R2, the damper comprises; a tank T in which an in-tank liquid chamber T1 stored with the working fluid and an in-tank air chamber T2 containing air are formed; and a first flow path 6 and a second flow path 7 making the tank T communicate with the reservoir R. In the first flow path 6, a tank-side opening 60 always faces the in-tank liquid chamber 1, and in the middle of the first flow path 6, there is arranged a supply check valve 6a which permits only movement from the in-tank liquid chamber T1 to the reservoir R. In the second flow path 7, a reservoir-side opening 71 faces the vicinity of the liquid face O1 of the reservoir R, and in the middle of the second flow path 7, there is arranged a discharge check valve 7a which permits only movement from the reservoir R to the tank T.

Description

  The present invention relates to an improvement of a shock absorber.

  For example, as disclosed in Patent Document 1, the shock absorber is used in a suspension device of a vehicle such as an automobile, and is supported by a cylinder and a head member fixed to the head portion of the cylinder so as to appear and disappear in the cylinder. And a rod that can be inserted.

  The head member is a bearing member that is formed in an annular shape and is attached to the inner periphery, and a rod guide that pivotally supports the rod. The head member is laminated on the rod guide and slidably contacts the outer periphery of the rod so that the working fluid in the cylinder is outside air And an annular sealing member for preventing outflow to the side.

  The shock absorber is slidably contacted with a piston that is held at the tip of the rod and divides the cylinder into two working chambers that are filled with working fluid, and an inner periphery of the bottom portion of the cylinder, and has a volume in the cylinder. And a free piston that partitions the compensation air chamber.

  Further, the shock absorber includes a flow path formed in the piston and communicating with the two working chambers, and a damping force generating means for generating a predetermined damping force when the working fluid passes through the flow path. Suppresses road surface vibration that is input to a running vehicle.

  Further, the working fluid is an aqueous fluid in the shock absorber, and thereby the damping force responsiveness is improved as compared with the case where the working fluid is mineral oil.

JP 2009-36257 A

  However, when the working fluid is not an oil but an aqueous fluid as in the conventional shock absorber, the following problems may be pointed out.

  That is, the seal member and the rod are kept in good lubricity by being in sliding contact with each other through the lubricating film, but the water-based fluid is poor in lubricity compared with oil, and the seal member and the rod slide between each other. In order to improve the property, it is necessary to increase the thickness of the lubricating film.

  However, when the lubricant film is thickened, the amount of working fluid that is exposed to the outside air when the rod is retracted increases, and accordingly, the amount of working fluid evaporated also increases, and the working fluid may be insufficient.

  Accordingly, an object of the present invention is to provide a shock absorber capable of solving the above-described problems and preventing a shortage of working fluid even when an aqueous fluid is employed as the working fluid.

  Means for solving the above problems include a cylinder, an outer cylinder that is coaxially disposed outside the cylinder and forms a reservoir between the cylinder, a rod that is inserted into the cylinder so as to be able to appear and retract, A piston that is held at the tip of the rod and divides the cylinder into two working chambers filled with working fluid, and a base that is fixed to the bottom of the cylinder and divides the working chamber on the piston side and the reservoir The reservoir includes a liquid in the reservoir in which the working fluid is stored and a liquid in the tank in which the working fluid is stored in a buffer including a reservoir internal chamber in which the gas is stored. A tank in which a chamber and an air chamber in a tank containing gas are formed, and a first flow path and a second flow path communicating the tank and the reservoir, the first flow The tank side opening always faces the liquid chamber in the tank, and in the middle of the first flow path, a supply check valve that allows only movement from the liquid chamber in the tank to the reservoir is provided. The second channel faces the vicinity of the boundary between the liquid chamber in the reservoir and the air chamber in the reservoir when the reservoir side opening is most compressed, and only the movement from the reservoir to the tank is in the middle of the second channel. Is provided with a check valve for discharging.

  According to the present invention, the working fluid in the tank is replenished via the supply check valve even if the working fluid evaporation amount increases and the working fluid in the cylinder becomes insufficient. It is possible to prevent a shortage of the working fluid even when the aqueous fluid is employed.

It is a longitudinal section showing the shock absorber concerning one embodiment of the present invention in principle.

  A shock absorber according to an embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, a shock absorber D according to the present embodiment includes a cylinder 1, an outer cylinder 2 that is coaxially disposed outside the cylinder 1 and forms a reservoir R between the cylinder 1, A rod 3 which is inserted into the cylinder 1 so as to be retractable, a piston 4 which is held at the tip of the rod 3 and divides the cylinder 1 into two working chambers P1 and P2 filled with a working fluid; A base member 5 is provided which is fixed to a bottom portion (lower part in FIG. 1) of the cylinder 1 and partitions the piston-side working chamber (pressure-side working chamber P2) and the reservoir R.

  The reservoir R includes a reservoir internal liquid chamber R1 in which a working fluid is stored and a reservoir internal air chamber R2 in which a gas is stored.

  Further, the shock absorber D includes a tank T in which a tank internal liquid chamber T1 in which a working fluid is stored, a tank internal air chamber T2 in which a gas is stored, and the tank T and the reservoir R. Are provided with a first flow path 6 and a second flow path 7.

  The first flow path 6 has a tank-side opening 60 that always faces the liquid chamber T1 in the tank, and in the middle of the first flow path 6, only the movement from the tank liquid chamber T1 to the reservoir R is allowed. A check valve 6a is provided.

  On the other hand, the second flow path 7 faces the vicinity of the boundary (liquid level O1) between the reservoir internal liquid chamber R1 and the reservoir internal air chamber R2 when the reservoir side opening 71 is most compressed, and the second flow path 7 In the middle, a discharge check valve 7a that allows only movement from the reservoir R to the tank T is provided.

  Describing in detail below, the shock absorber D according to the present embodiment is used in a suspension device of a vehicle such as an automobile, and a reservoir R is formed between the cylinder 1 and the outer cylinder 2 to form a double cylinder type. Configure the shock absorber.

  The shock absorber D is set upright with the rod 3 fixed to the vehicle body and the cylinder 1 and the outer cylinder 2 fixed to the wheel.

  The cylinder 1 has a head member 8 fixed to the upper opening in FIG. 1 and a base member 5 fixed to the lower opening in FIG. A working fluid is filled between the head member 8 and the base member 5 in the cylinder 1 to form working chambers (P1, P2). The working chambers (P1, P2) are located in the cylinder 1. The piston 4 is slidably inserted and is divided vertically. Hereinafter, the rod-side working chamber located on the upper side in FIG. 1 is referred to as an extension working chamber P1, and the piston-side working chamber located on the lower side in FIG. 1 is referred to as a pressure-side working chamber P2.

  A cylinder lower chamber P3 that is similarly filled with a working fluid is formed in the cylinder 1 below the base member 5 in the drawing. The working fluid in the cylinder lower chamber P3 can freely move between the reservoir inner fluid chamber R1 through a through hole 10 formed in the cylinder 1 and facing the cylinder lower chamber P3.

  The head member 8 includes a rod guide 80 that pivotally supports the rod 3 with a bearing member 8a attached to the inner periphery, and an annular seal member 81 stacked on the outside air side (upper side in FIG. 1) of the rod guide 80. Prepare.

  The rod guide 80 has a bearing main body 80a whose outer peripheral portion is fitted to the outer cylinder 2 and closes the upper end of the reservoir R in FIG. 1, and is suspended from the lower end of the bearing main body 80a in FIG. 1 is provided with a fitting portion 80b fitted to the upper end portion.

  The seal member 81 is laminated on the bearing main body 80a and is fixed to the cylinder 1 and the outer cylinder 2 integrally with the rod guide 80. The inner peripheral seal 81a is slidably contacted with the outer periphery of the rod 3 so as to be within the cylinder 1. This prevents the working fluid from flowing out to the outside air side.

  The piston 4 held at the tip of the rod 3 has an extension side damping force provided in the middle of the extension side channel 40 and the extension side channel 40 and the extension side channel 40 communicating the two working chambers P1 and P2. A generation valve V1 and a pressure side check valve C1 provided in the middle of the pressure side flow path 41 are provided.

  The extension side damping force generation valve V1 allows only the movement of the working fluid from the extension side working chamber P1 to the pressure side working chamber P2, and is set to have a high valve opening pressure, and has a high flow resistance when the working fluid moves. To generate the main extension side damping force.

  On the other hand, the pressure-side check valve C1 allows only movement of the working fluid from the pressure-side working chamber P2 to the extension-side working chamber P1, and is easily opened with a low valve opening pressure.

  Further, the base member 5 fixed to the bottom portion of the cylinder 1 has an extension side flow path 50 and a pressure side communicating with the pressure side working chamber P2, the cylinder lower chamber P3, and the reservoir liquid chamber R1 through the through hole 10. The flow path 51, the expansion side check valve C2 provided in the middle of the expansion side flow path 50, and the pressure side damping force generation valve V2 provided in the middle of the pressure side flow path 51 are provided.

  The extension side check valve C2 allows only the movement of the working fluid from the reservoir side to the pressure side working chamber P2, and is easily opened with a low valve opening pressure.

  On the other hand, the pressure-side damping force generation valve V2 allows only the movement of the working fluid from the pressure-side working chamber P2 to the reservoir side, and is set to have a high valve opening pressure, and has a high flow path resistance when the working fluid moves. The main compression side damping force is generated.

  By the way, the reservoir R formed between the cylinder 1 and the outer cylinder 2 is formed on the upper side via the liquid chamber R1 in the reservoir and the liquid level O1 of the liquid chamber R1 in the reservoir, and contains gas. 1 is closed by the head member 8 and the lower side in FIG. 1 is closed by the bottom member 20.

  The reservoir R communicates with a tank T disposed outside the outer cylinder 2 via the first flow path 6 and the second flow path 7, and the working fluid is stored inside the tank T. The tank liquid chamber T1 and the tank air chamber T2 formed on the upper side through the liquid surface O2 of the tank liquid chamber T1 and containing gas are contained.

  The tank-side opening 60 of the first flow path 6 is provided at the bottom of the tank T and always faces the liquid chamber T1 in the tank, and the reservoir-side opening 61 of the first flow path 6 is the same as that shown in FIG. It is provided in the middle and lower part and always faces the liquid chamber R1 in the reservoir.

  Therefore, the first flow path 6 communicates between the tank liquid chamber T1 and the reservoir liquid chamber R1. In the middle of the first flow path 6, a supply check valve 6a that allows only movement from the tank liquid chamber T1 to the reservoir liquid chamber R1 is provided.

  On the other hand, the tank-side opening 70 of the second flow path 7 is provided in the ceiling portion of the tank T and always faces the tank air chamber T2, and the reservoir-side opening 71 of the second flow path 7 is formed on the outer cylinder 2. 1 is provided near the liquid surface O1 of the liquid chamber R1 in the reservoir when the shock absorber D is most compressed.

  Therefore, the second flow path 7 communicates the tank air chamber T2 and the reservoir liquid chamber R1 even when the tank air chamber T2 and the reservoir air chamber R2 communicate with each other depending on the amount of the working fluid stored in the reservoir R. There is also a case. In the middle of the second flow path 7, a discharge check valve 7 a that allows only the working fluid or gas to move to the tank side is provided.

  Moreover, in this Embodiment, the working fluid accommodated in the cylinder 1, the reservoir | reserver R, and the tank T is a water-system fluid, and this water-system fluid is the glycol aqueous solution which added glycols to water. Examples of the glycols include ethylene glycol and propylene glycol.

  Next, the operation and effect of the shock absorber D in the present embodiment will be described. When the shock absorber D is extended so that the rod 3 retracts from the cylinder 1, the expansion side action chamber P1 is pressurized, and the extension side action chamber P1 The working fluid pushes the extension side damping force generation valve V1 of the piston 4 and moves to the pressure side working chamber P2.

  At this time, the working fluid corresponding to the volume of the retracted rod 3 is insufficient in the cylinder 1, so that the insufficient working fluid opens the extension side check valve C <b> 2 of the base member 5 and flows into the cylinder 1.

  Then, since the working fluid moves from the reservoir R into the cylinder 1, the internal pressure of the reservoir R decreases, the supply check valve 6 a opens, and the working fluid moves from the tank T to the reservoir R via the first flow path 6. The internal pressures of the tank T and the reservoir R become equal.

  On the other hand, at the time of compression of the shock absorber D in which the rod 3 enters the cylinder 1, the pressure side working chamber P2 is pressurized, and the working fluid in the pressure side working chamber P2 opens the pressure side check valve C1 of the piston 4 to act on the extending side. Move to chamber P1.

  At this time, since the working fluid for the volume of the rod 3 that has entered becomes surplus in the cylinder 1, the surplus working fluid pushes open the compression side damping force generation valve V <b> 2 of the base member 5 and flows into the reservoir R.

  Then, since the working fluid flows into the reservoir R, the internal pressure of the reservoir R rises and the discharge check valve 7a is opened. At this time, when the liquid level O1 of the reservoir R is positioned above the reservoir side opening 71 of the second flow path 7 in FIG. 1, the working fluid moves from the reservoir R to the tank T, and the liquid level of the reservoir R When O1 is positioned below the reservoir side opening 71 of the second flow path 7 in FIG. 1, the gas moves from the reservoir R to the tank T, and the internal pressures of the tank T and the reservoir R become equal.

  That is, the shock absorber D pushes open the extension side damping force generation valve V1 of the piston 4 and extends the passage resistance when passing through the extension side passage 40 and the extension side check valve C2 of the base member 5 during extension. An extension side damping force is generated due to the flow path resistance when opening and passing through the extension side flow path 50.

  Further, the shock absorber D pushes the compression side damping force generation valve V2 of the base member 5 and opens the pressure resistance when passing through the pressure side flow channel 51, and the pressure side check valve C1 of the piston 4 during compression. A compression side damping force due to the flow path resistance when passing through the flow path 41 is generated.

  Further, the shock absorber D repeats the expansion and contraction, so that when the liquid level O1 of the reservoir R becomes higher than the reservoir-side opening 71 of the second flow path 7, the working fluid of the reservoir R and the working fluid of the tank T When the liquid level O1 of the reservoir R becomes lower than the reservoir-side opening 71 of the second flow path 7, the gas in the reservoir R and the working fluid in the tank T are replaced.

  That is, only the working fluid is supplied from the tank T to the reservoir R due to the expansion and contraction of the shock absorber D. Therefore, even if the working fluid attached to the outer periphery of the rod 3 evaporates, the working fluid is insufficient in the cylinder 1 and the reservoir R. This can be prevented.

  Further, when the working fluid is supplied to the reservoir R and the amount of the working fluid stored in the reservoir R exceeds a certain level, the liquid level O1 of the reservoir R is more than the reservoir-side opening 71 of the second flow path 7. Since it is located on the upper side in FIG. 1, the working fluid does not flow into the tank T via the discharge check valve 7 a and the working fluid in the reservoir R does not increase excessively.

  That is, the position where the reservoir-side opening 71 of the second flow path 7 is provided should be provided at a position where the working fluid in the reservoir R does not become too much, which is the buffer D where the liquid level O1 of the reservoir R becomes the highest. This can be realized by setting the position of the desired liquid level O1 at the time of the most contraction, and the vicinity of the boundary between the reservoir internal liquid chamber R1 and the reservoir internal air chamber R2 at the time of the maximum compression in the claims is the position of the desired liquid level O1. It means something.

  In the present embodiment, since the reservoir side opening 61 of the first flow path 6 is always provided at a position facing the liquid chamber R1 in the reservoir, the working fluid in the tank T is not contained in the reservoir without passing through the reservoir air chamber R2. It moves to liquid chamber R1, and it becomes possible to prevent that a bubble mixes in a working fluid.

  In the present embodiment, since the reservoir-side opening 61 of the first flow path 6 is provided at the bottom of the tank T, the reservoir-side opening 61 is always kept in the reservoir while minimizing the amount of working fluid accommodated in the tank T. It is possible to face the liquid chamber R1.

  Further, in the present embodiment, the working fluid is composed of an aqueous fluid, and the aqueous fluid is less likely to be compressed than oil, and it is possible to improve the response of generating a damping force.

  Although preferred embodiments of the present invention have been described in detail above, it should be understood that modifications, variations and changes may be made without departing from the scope of the claims.

  For example, the shock absorber D in the above embodiment is used in a suspension device of a vehicle such as an automobile, but is not limited to this, and may be used in other devices.

  Further, in the above embodiment, the reservoir side opening 61 of the first flow path 6 always faces the liquid chamber R1 in the reservoir, but may also face the air chamber R2 in the reservoir.

  Further, in the above embodiment, the tank side opening 70 of the second flow path 7 always faces the tank internal air chamber T2, but may also face the tank internal liquid chamber T1.

  Further, in FIG. 1, the tank T is described separately from the outer cylinder 2, but a tube may be coaxially disposed outside the outer cylinder 4, and a tank may be provided between the tube and the outer cylinder 4. .

  Moreover, although the working fluid in the said embodiment was made into the glycol aqueous solution which is an aqueous fluid, you may utilize the thing which added the rust preventive to water, even if it uses water alone as an aqueous fluid.

C1 Pressure side check valve C2 Extension side check valve D Buffers O1, O2 Liquid level P1 Extension side action chamber P2 Pressure side action chamber R Reservoir R1 Reservoir inside liquid chamber R2 Reservoir inside air chamber T Tank T1 Tank inside liquid chamber T2 Tank inside air chamber V1 Extension Side damping force generation valve V2 Pressure side damping force generation valve 1 Cylinder 2 Outer cylinder 3 Rod 4 Piston 5 Base member 6 First flow path 6a Supply check valve 7 Second flow path 7a Discharge check valve 8 Head member 10 Through hole 20 Bottom Members 40, 50 Extension side flow path 41, 51 Pressure side flow path 60, 70 Tank side opening 61, 71 Reservoir side opening

Claims (4)

A cylinder, an outer cylinder that is coaxially disposed outside the cylinder and forms a reservoir between the cylinder, a rod that is removably inserted into the cylinder, and a cylinder that is held at a tip of the rod and that is held at the tip of the rod A piston that divides the inside into two working chambers filled with working fluid, and a base member that is fixed to the bottom portion of the cylinder and divides the working chamber on the piston side and the reservoir,
The reservoir is a shock absorber composed of a reservoir liquid chamber in which a working fluid is stored and a reservoir air chamber in which a gas is stored.
A tank in which a working fluid is stored in a tank, a tank in which a gas is stored, and a tank in which a working fluid is stored; a first flow path and a second flow path communicating the tank and the reservoir; With
The first channel has a tank-side opening that always faces the liquid chamber in the tank, and a supply check valve that allows only movement from the tank liquid chamber to the reservoir is provided in the middle of the first channel. And
The second channel faces the vicinity of the boundary between the liquid chamber in the reservoir and the air chamber in the reservoir when the reservoir-side opening is at the maximum compression, and moves from the reservoir to the tank in the middle of the second channel. A shock absorber characterized by being provided with a discharge check valve that only allows the discharge.   The shock absorber according to claim 1, wherein the reservoir-side opening of the first flow path is always provided at a position facing the liquid chamber in the reservoir.   The shock absorber according to claim 1 or 2, wherein a tank side opening of the first flow path is provided at a bottom portion of the tank.   The shock absorber according to any one of claims 1 to 3, wherein the working fluid is an aqueous fluid.

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