JP4432372B2 - Shock absorber with vehicle height adjustment function - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shock absorber with a vehicle height adjustment function.
[0002]
[Prior art]
Conventionally, a damper with a vehicle height adjusting function has been proposed (for example, Patent Document 1).
In this damper with a vehicle height adjusting function, a cylindrical case connected to a damper rod is provided on the outside of the damper body so as to be movable up and down, and a pressure in which a pressure medium changing gas and liquid is enclosed between the damper body and the case. A chamber is formed, and the pressure medium sealed in the pressure chamber is superheated by an electric heater. Thereby, the damper main body is raised by the vapor pressure of the pressure medium, and the vehicle height is raised.
Further, in this damper with a vehicle height adjusting function, an inner / outer double structure is formed by an inner case that encloses a pressure medium in the case and an outer case outside the inner case, and the adiabatic air is provided between the inner case and the outer case. Forming a layer.
[0003]
[Patent Document 1]
JP 2000-205326 A
[0004]
[Problems to be solved by the invention]
The damper with the vehicle height adjusting function requires a case for accommodating the damper main body in order to enclose the pressure medium, and thus has a large structure as a whole. For example, it is larger than a monotube shock absorber. In this case, the suspension layout in the vehicle is restricted.
Further, since the method of heating and vaporizing the pressure medium is adopted, it is easily affected by the outside air temperature. As a countermeasure, the case is composed of an inner case and an outer case, and a heat insulating air layer is formed between the inner case and the outer case. This increases the overall weight.
[0005]
In addition, since the method of heating and vaporizing the pressure medium is employed, it takes time for the phase change such as vaporization or liquefaction of the pressure medium. This has a problem as responsiveness as a vehicle height adjustment function. In addition, in order to adjust the temperature of the pressure medium, it is actually necessary to provide a reservoir tank, cooling water, and a cooling water pump, and management thereof is necessary. As a result, procedures that require complicated vehicle height adjustment are required.
[0006]
The case is attached to the outside of the damper main body via a seal in order to prevent pressure leakage of the pressure medium. However, the increase in the number of seals increases the friction with respect to the suspension movement, and as a result, the ride quality is affected. Further, since the seal is provided on the outer cylinder of the damper main body, the processing accuracy of the damper is required. This increases the cost. In addition, as long as the case is attached with a seal, it is inevitable that pressure leakage will occur due to wear due to movement.
Therefore, the present invention has been made in view of the above-described problems, and an object thereof is to provide a shock absorber with a vehicle height adjusting function that can easily adjust the vehicle height while simplifying the structure.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problem, a shock absorber with a vehicle height adjusting function according to the present invention includes a rod connected to either the vehicle body side member or the wheel side member, and either the vehicle body side member or the wheel side member. A tube connected to the other, a piston built in the tube and connected to the rod, and a free piston built in the tube on the opposite side of the rod from the rod. And a monotube type shock absorber that forms a pressure chamber defined by the free piston and the tube on the side opposite to the piston to which the rod is connected to the free piston.
The shock absorber with a vehicle height adjusting function according to the present invention separately opens and closes the pressurizing flow path and the pressure reducing flow path, and the pressurizing flow path and the depressurizing flow path communicating the pressure chamber and the pressure source. A possible valve and a high-pressure accumulator provided between the pressure source and the valve in the pressurizing flow path.
In the shock absorber with a vehicle height adjusting function according to the present invention, the piston to which the rod is connected is provided with an orifice hole that communicates the arrangement side of the rod and the arrangement side of the free piston in the tube. .
Furthermore, the shock absorber with a vehicle height adjusting function according to the present invention sets the vehicle height by pressurizing or depressurizing the pressure chamber and adjusting the positions of the piston and the rod.
The vehicle height adjusting function with shock absorber according to the present invention, pressure or of the pressure chamber is carried out by opening and closing the valve under reduced pressure, when it becomes a predetermined set vehicle height, the pressure closing the valve The communication state by the pressure channel and the pressure channel is blocked.
[0008]
【The invention's effect】
According to the present invention, the vehicle height can be set by using the structure of the monotube shock absorber and simply pressurizing or depressurizing the pressure chamber formed in the structure of the monotube shock absorber. Thereby, the vehicle height can be easily adjusted while simplifying the structure.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The first embodiment is a shock absorber with a vehicle height adjusting function to which the present invention is applied.
As shown in FIG. 1, the shock absorber with a vehicle height adjusting function includes a shock absorber body 1, a pressure increasing / decreasing flow path 21 connected to the volume chamber γ of the shock absorber body 1, and the pressure increasing / decreasing flow path 21. The high-pressure accumulator 23 and the high-pressure pump 24 arranged above, a valve 25 for adjusting the pressure in the volume chamber γ, a pressure sensor 26 for detecting the pressure in the volume chamber γ, and the opening and closing of the valve 25 are controlled. And a vehicle height control unit 28 for controlling the valve controller 27 to set the vehicle.
[0010]
The shock absorber body 1 has the same configuration as an upright monotube shock absorber. The shock absorber body 1 includes a damper rod 2 that is connected to the vehicle body side member and moves integrally with the vehicle body, and a tube 3 that is connected to the wheel side member and moves integrally with the wheel. The damper rod 2 is supported by a damper rod guide 4 provided so as to close the upper end of the tube 3 so as to be movable forward and backward. The damper rod guide 4 includes a guide portion 4 a that supports the outer periphery of the damper rod 2, and a packing 4 b that forms a sliding surface with the damper rod 2 in the lot guide 4.
[0011]
A piston 5 that slides in the tube 3 is attached to the lower end of the damper rod 2. The piston 5 divides the inside of the tube 3 into upper and lower chambers, and the piston 5 is formed with orifice holes (not shown) that communicate the upper and lower chambers thus partitioned. A free piston 6 is arranged in the tube 3 below the piston 5.
[0012]
Thus, in the tube 3, a piston upper chamber α that is a compartment defined by the piston 5 is disposed above the piston 5, a piston lower chamber β that is a compartment defined by the piston 5 is disposed below the piston 5, and a piston of the free piston 6. Volume chambers γ, which are pressure chambers, are respectively formed below. Oil is sealed in the piston upper chamber α and the piston lower chamber β, and a working fluid for pressure increase / decrease is sealed in the volume chamber γ. The working fluid is, for example, a gas body or a liquid.
[0013]
A spring receiver 7 is attached to the outer periphery of the tube 3, and a spring receiving plate (or bracket) 8 is attached to the upper end of the damper rod 2, and the spring receiver 7 and the damper of the tube 3 are attached. A spring 9 is interposed between the rod 2 and the spring receiving plate 8.
Further, a bush 10 connected to a suspension arm or the like that forms a wheel side member is formed at the lower end of the tube 3.
[0014]
And the pressure-reduction channel 21 is connected to the side surface of the lower end portion of the tube 3 at two locations so as to communicate with the volume chamber γ. Specifically, they are connected via connection sockets 31 and 32 attached to the side surface of the tube 3. By means of the connection sockets 31, 32, the pressure-intensifying flow path 21 is detachable from the tube 3. The pressure / reduction channel 21 is, for example, a pressure hose.
[0015]
Here, both ends of the pressure-reducing channel 21 are configured as circuits connected to the tube 3 as described above, that is, one channel communicated with the volume chamber γ in the pressure-reducing channel 21. Constitutes a pressurizing flow path, and the other flow path communicated with the volume chamber γ by the pressure increasing / decreasing flow path 21 constitutes a pressure reducing flow path.
A valve 25, a high-pressure accumulator 23, and a high-pressure pump 24 are disposed on the pressure / reduction channel 21.
[0016]
The high-pressure pump 24 is for increasing the pressure in the volume chamber γ with the high-pressure accumulator 23. Here, the high-pressure pump 24 and the high-pressure accumulator 23 are part of a pressure generator used in ABS (anti-lock brake system) and VDC (vehicle dynamics control). That is, the high-pressure pump 24 and the high-pressure accumulator 23 are pressure sources that are also used in other in-vehicle systems.
[0017]
The valve 25 is arranged so that the pressurizing flow path and the depressurizing flow path can be freely opened and closed. The valve 25 is provided with a pressure sensor 26 for detecting the pressure of the pressure-increasing / depressurizing flow path 21, that is, the pressure in the volume chamber γ. The valve 25 is controlled to be opened and closed by a valve controller 27. The valve controller 27 controls opening and closing of the valve 25 based on the pressure detected by the pressure sensor 26 so that the inside of the volume chamber γ becomes a predetermined pressure.
[0018]
The vehicle height setting unit 28 uses the valve controller 27 to control the pressure in the volume chamber γ and sets it to a predetermined vehicle height. Specifically, when the vehicle height is set high, the vehicle height setting unit 28 opens the volume chamber γ by opening the pressurization flow passage side of the valve 25 and closing the pressure reduction flow passage side by the valve controller 27. Increase pressure. Further, when setting the vehicle height low, the vehicle height setting unit 28 opens the pressure reducing passage side of the valve 25 by the valve controller 27 and closes the pressurizing passage side to reduce the volume chamber γ. Further, the vehicle height setting unit 28 closes the pressurizing passage side and the depressurizing passage side of the valve 25 by the valve controller 27 when the pressure is increased or reduced to a predetermined vehicle height.
[0019]
As described above, the shock absorber with a vehicle height adjusting function is configured.
Next, the operation will be described.
As described above, the shock absorber with a vehicle height adjusting function opens the pressurizing flow channel side of the valve 25 by the valve controller 27 and closes the pressure reducing flow channel side when the vehicle height is set to be high. The inside of γ is increased. When the vehicle height is set to a low level, the shock absorber with a vehicle height adjusting function opens the pressure reducing channel side of the valve 25 by the valve controller 27 and closes the pressurizing channel side so that the inside of the volume chamber γ The pressure is reduced.
[0020]
2A schematically shows the operation of the shock absorber body 1 when the pressure in the volume chamber γ is increased, and FIG. 2B shows the pressure in the volume chamber γ. The operation | movement in the shock absorber main body 1 at the time of a case is shown typically. In order to explain the operation, the upper and lower surface areas (pressure receiving surface areas) S5 ′ and S5 of the piston 5 and the upper and lower surface areas (pressure receiving surface area) S6 of the free piston 6 are shown highlighted.
[0021]
As shown in FIG. 2A, when the pressure flow passage side is opened by the valve 25 and the pressure reduction flow passage side is closed to increase the pressure in the volume chamber γ, the free piston 6 rises in the tube 3. As a result, the piston 5 and the damper rod 2 also rise. As a result, the vehicle height increases.
Further, as shown in FIG. 2B, when the pressure channel side is closed by the valve 25 and the pressure reducing channel side is opened to depressurize the volume chamber γ, the free piston 6 moves inside the tube 3. As a result, the piston 5 and the damper rod 2 are also lowered. As a result, the vehicle height decreases.
[0022]
For example, even if the inside of the volume chamber γ is increased or decreased, the pressures of the piston upper chamber α, the piston lower chamber β, and the volume chamber γ finally become constant at pressures balanced with each other. For example, when the pressure at this time is P, the following equation (1) is established.
S6 · P> S5 · P> S5 ′ · P (1)
The relationship of the expression (1) is obtained by the relationship between the pressure receiving surface areas S5 ′ and S5 of the piston 5 and the pressure receiving surface area S6 of the free piston 6 being established as the following expression (2).
[0023]
S6>S5> S5 ′ (2)
Here, in the piston 5, the upper pressure receiving surface area S 5 ′ is smaller than the lower pressure receiving surface area S 5 by the sectional integral of the damper rod 2. Further, the lower pressure receiving surface area S5 of the piston 5 is smaller than the pressure receiving surface area S6 of the free piston 6 by the amount of the orifice hole. For this reason, the expression (2) is established between the pressure receiving surface areas S5 ′ and S5 of the piston 5 and the pressure receiving surface area S6 of the free piston 6.
[0024]
From such a relationship, the vehicle height is increased by increasing the pressure in the volume chamber γ so that the pressure P becomes larger than the pressure of the vehicle height when the vehicle is neutral, and the pressure P is increased when the vehicle is neutral. The vehicle height is lowered by reducing the volume of the volume chamber γ so as to be smaller than the above pressure.
Further, the shock absorber with a vehicle height adjusting function closes the pressure channel side and the pressure channel side of the valve 25 by the valve controller 27 when a predetermined vehicle height is reached. Thereby, the shock absorber main body 1 comes to function as a monotube type shock absorber.
[0025]
Next, the effect will be described.
As described above, the vehicle height is set by pressurizing or depressurizing the inside of the volume chamber γ and adjusting the positions of the piston 5 and the damper rod 2. That is, by using the structure of the monotube type shock absorber and simply pressurizing or depressurizing the inside of the volume chamber γ formed in the structure of the monotube type shock absorber, it can be set to a predetermined vehicle. Thereby, the vehicle height can be easily adjusted while simplifying the structure. Thus, since the vehicle height adjustment function is realized using the structure of the monotube type shock absorber, the degree of freedom of suspension layout when the vehicle height adjustment function-equipped shock absorber is mounted can be improved.
[0026]
Further, as described above, the valve 25 is opened and closed to pressurize or depressurize the volume chamber γ, and the valve 25 is closed when a predetermined set vehicle height is reached. Thereby, the shock absorber main body 1 is made to function as a monotube type shock absorber. That is, the shock absorber body 1 can function as a monotube type shock absorber only by closing the valve 25. Therefore, no other energy is required when functioning as a shock absorber.
[0027]
In addition, the realization of the vehicle height adjustment function does not increase the seal (packing) structure as in the technique of Patent Document 1 described above. As a result, the increase in the seal structure increases the friction with respect to the suspension movement and does not deteriorate the riding comfort.
Further, as described above, the high-pressure pump 24 and the high-pressure accumulator 23 are part of the pressure generator used in the ABS and VDC, that is, the pressure source used in other in-vehicle systems. Can be used effectively to realize a shock absorber with a vehicle height adjustment function. In ABS and VDC, the high-pressure pump 24 is operated in an emergency of vehicle behavior and stored in the high-pressure accumulator 23. Therefore, the high-pressure pump 24 is not always operated. For this reason, it is possible to effectively use a device that is not always used in other systems.
[0028]
Next, a second embodiment will be described.
FIG. 3 shows a shock absorber with a vehicle height adjusting function according to the second embodiment. In the second embodiment, as shown in FIG. 3, the shock absorber body 1 is configured as a so-called inverted type in which the volume chamber γ is positioned above the shock absorber body 1.
[0029]
Specifically, a spring receiving plate 11 is attached to the lower end of the damper rod 2, and a bush 12 connected to a suspension arm or the like is formed on the lower surface of the spring receiving plate 11. A bracket 12 attached to the vehicle body side is provided at the upper end of the tube 3 in which the volume chamber γ is formed. Then, the pressure-reducing flow path 21 is provided at two positions on the side surface of the lower end portion of the tube 3 via the connection sockets 31 and 32 so as to communicate with the volume chamber γ positioned above the shock absorber 1. It is connected.
[0030]
Thus, the shock absorber with a vehicle height adjustment function of the second embodiment is configured, and the operation is the same as that of the shock absorber with a vehicle height adjustment function of the first embodiment described above.
That is, the shock absorber with a vehicle height adjusting function of the second embodiment opens the pressurizing flow passage side of the valve 25 and closes the pressure reducing flow passage side by the valve controller 27 when the vehicle height is set high. Thus, the pressure in the volume chamber γ is increased. When the vehicle height is set low, the shock absorber with a vehicle height adjusting function decompresses the volume chamber γ by opening the pressure reducing channel side of the valve 25 by the valve controller 27 and closing the pressurizing channel side. I am letting. Thus, the vehicle height is increased by increasing the pressure in the volume chamber γ, and the vehicle height is decreased by decreasing the pressure in the volume chamber γ. Further, when a predetermined vehicle height is reached, the valve controller 27 closes the pressurizing flow path side and the depressurizing flow path side of the valve 25. Thereby, the shock absorber main body 1 is made to function as a monotube type shock absorber.
[0031]
4 and 5 show a vehicle configuration provided with a shock absorber with a vehicle height adjusting function according to the second embodiment. FIG. 4 shows the configuration on the front wheel side, and FIG. 5 shows the configuration on the rear wheel side. 4 and 5, 41 is an engine and a transmission, 42 is a front wheel, 51 is a rear wheel, 43 and 53 are suspension structure lower links, and 44 and 54 are suspension structure upper links. And 45 and 55 are suspension structure axles, and 56 is a suspension member of the suspension structure.
[0032]
As shown in FIGS. 4 and 5, the general suspension structure and its peripheral structure can be maintained, and the shock absorber main body 1 can be inverted and incorporated into the vehicle in the same manner as the monotube type shock absorber.
Next, the effect will be described.
For example, as in the case of the first embodiment described above, when the shock absorber main body 1 is in an upright arrangement, the volume chamber γ is at the bottom, and the pressure increasing / decreasing flow path 21 is also arranged below. .
[0033]
However, there are also brake lines, vehicle speed sensor lines, and the like at the lower position, and there is a possibility that the pressure-intensifying flow path 21 may interfere with them. Moreover, since the heavy part of the shock absorber body is attached to the attachment point side to the lower link, the unsprung load of the vehicle is increased. In the second embodiment, the pressure increasing / decreasing flow path 21 is arranged in the upper part by raising the volume chamber γ as an inverted type. Thereby, it can prevent that the flow path 21 for pressure increase / decrease interferes with a brake line, a vehicle speed sensor line, etc., and also can prevent the increase in the unsprung load of a vehicle.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a shock absorber with a vehicle height adjusting function according to a first embodiment of the present invention.
FIG. 2 is a view used for explaining the operation of the shock absorber with a vehicle height adjusting function.
FIG. 3 is a diagram showing a configuration of a shock absorber with a vehicle height adjusting function according to a second embodiment of the present invention.
FIG. 4 is a diagram showing a configuration on a front wheel side of a vehicle provided with a shock absorber with a vehicle height adjusting function according to a second embodiment of the present invention.
FIG. 5 is a diagram showing a configuration of a rear wheel side of a vehicle provided with a shock absorber with a vehicle height adjusting function according to a second embodiment of the present invention.
[Explanation of symbols]
1 Shock absorber body 1
2 Damper rod 3 Tube 4 Damper rod guide 5 Piston 6 Free piston 9 Spring 21 Pressure increasing / decreasing flow path 23 High pressure accumulator 24 High pressure pump 25 Valve 26 Pressure sensor 27 Valve controller 28 Vehicle height control section 31, 32 Connection socket

Claims (3)

A rod connected to either the vehicle body side member or the wheel side member, a tube connected to the other of the vehicle body side member or the wheel side member, and an interior of the tube, and the rod connected A piston and a free piston housed in the tube on the opposite side of the rod from the piston, the free piston on the opposite side of the free piston from the piston to which the rod is connected. piston and provided with a monotube shock absorber that forms a pressure chamber which is defined by the tube Rutotomoni, the pressurizing channel and pressure reducing channel which communicates with the pressure chamber and the pressure source, the pressurizing channel and A valve capable of individually opening and closing the decompression flow path, and a high-pressure accumulator provided between the pressure source and the valve in the pressurization flow path,
The piston connected to the rod is provided with an orifice hole that communicates the arrangement side of the rod and the arrangement side of the free piston in the tube.
The vehicle height is set by pressurizing or depressurizing the pressure chamber and adjusting the position of the piston and rod,
Pressure or of the pressure chamber is carried out by opening and closing the valve under reduced pressure, when it becomes a predetermined set ride height, to block the communication state by the pressurizing passage and pressure reducing channel by closing the valve Shock absorber with height adjustment function. The pressure source is a pressure source used in other in- vehicle systems ,
Pressure detecting means for detecting the pressure in the pressure chamber, and control means for controlling the opening and closing of the valve based on the pressure in the pressure chamber detected by the pressure detecting means to pressurize or depressurize the pressure chamber ; The shock absorber with a vehicle height adjusting function according to claim 1.   The shock with a vehicle height adjusting function according to claim 1, wherein the pressurizing flow path and the depressurizing flow path are connected to a radial side surface at an end portion of the tube that defines the pressure chamber. Absorber.

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