JP3547363B2 - Suspension equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle suspension device using gas pressure.
[0002]
[Prior art]
A suspension device for a vehicle supports a vehicle body on a spring while buffering vibrations and impacts of wheels generated by large and small irregularities existing on a road surface so as not to be directly transmitted to the vehicle body. During traveling, the road surface irregularities change in various ways, and the suspension device absorbs vertical vibrations and rolls of the vehicle body caused by these road surface irregularities as much as possible, in addition to springs, to ensure the stability of the occupant. Often a damper is installed.
[0003]
Lowering the center of gravity of the vehicle increases running stability, so it is advantageous to lower the minimum ground clearance of the vehicle body.On the other hand, where the unevenness of the road surface is large, it is better to increase the minimum ground clearance. , Improve running performance. In response to such a demand, a vehicle height-adjustable suspension as shown in FIG. 10 has been developed.
[0004]
In this vehicle height-adjustable suspension, a knuckle 103 is pin-coupled to a vehicle body lower base 100 via an upper arm 101 and a lower arm 102, and a wheel 104 is rotatably supported by the knuckle 103. The upper arm 101 and the vehicle body upper base 105 are connected via a coil spring 107 with a damper 106 and an air cylinder 108 as an air spring which are provided side by side.
[0005]
As shown in FIG. 11, an air tank 110 filled with high-pressure air is connected to the air cylinder 108 via a solenoid valve 109, and by controlling the solenoid valve 109, high-pressure air is supplied from the air tank 110 to the air cylinder 108. Or discharge high-pressure air from the air cylinder 108 to the atmosphere. By the action of the solenoid valve 109, the air pressure in the air cylinder 108 is increased or decreased to adjust the vehicle height.
[0006]
[Problems to be solved by the invention]
Since the conventional air cylinder 108 exerts a function as an air spring by high-pressure air sealed in a gas chamber in the air cylinder 108, the withstand load of the air cylinder 108 is limited by the volume of the gas chamber and the sealed capacity. It is determined by various requirements such as air pressure. Among these requirements, the air pressure in the gas chamber needs to be within a predetermined limit in order to ensure a flexible suspension function, so that the withstand load of the air cylinder 108 is actually substantially determined by its size. .
[0007]
Therefore, in order to increase the load capacity of the air cylinder, the size of the air cylinder must be increased, and only the air cylinder having a relatively small load capacity can be installed around the wheel with limited space.
[0008]
Therefore, an object of the present invention is to provide a suspension device capable of increasing a load resistance while avoiding an increase in the size of the device.
[0009]
[Means for Solving the Problems]
The suspension device according to the present invention includes an outer cylinder in which one end of the cylindrical body is closed by an upper lid, and a bottom cover having a base end of the cylindrical body having an outer diameter smaller than the inner diameter of the cylindrical body. The inner cylinder, which is disposed in such a manner that the outer cylinder piston is airtightly slidably contacted with the outer peripheral surface of the outer cylinder in a shape in which the outer cylinder piston is closed by the outer cylinder piston, and the outer cylinder piston is airtight A piston shaft slidably penetrating and having a base end fixed to the upper lid, and an inner cylinder piston fixed to the piston shaft and slidably disposed on the inner peripheral surface of the inner cylinder. ing.
[0010]
With such a configuration, the outer cylinder and the inner cylinder are arranged in a nested manner, and the outer cylinder is located between the outer cylinder piston and the upper lid, and between the inner cylinder piston and the bottom lid, respectively. An airtight gas chamber that expands and contracts due to the relative reciprocating sliding motion of the inner cylinder and the internal cylinder is formed, and the suspension function is exhibited by the sealed gas pressure in these two gas chambers, thereby avoiding an increase in the size of the device. In addition, it is possible to increase the withstand load.
[0011]
A gas flow path is formed in the piston shaft that communicates the lower gas chamber divided by the bottom lid and the inner cylinder piston and the upper gas chamber divided by the upper lid and the outer cylinder piston. As a result, the gas pressure in the upper gas chamber and the gas pressure in the lower gas chamber are always kept equal, and the applied load is equally shared by the gas in the upper and lower gas chambers. Therefore, it is possible to prevent adverse effects due to the concentrated load on one of the gas chambers, and to obtain a smooth suspension function.
[0012]
By providing a reserve tank that communicates with the gas flow path via a first orifice mechanism, when a load is applied to the external cylinder or the internal cylinder and the gas in the upper gas chamber and the lower gas chamber is compressed, the gas becomes When the gas flows into the reserve tank via the first orifice mechanism, and conversely, when the load is reduced or released and the gas pressures in the upper gas chamber and the lower gas chamber are reduced, the gas in the reserve tank passes through the first orifice mechanism. And flows into the upper gas chamber and the lower gas chamber.
[0013]
Since these gases are sealed in the upper gas chamber, the lower gas chamber, and the reserve tank as a whole, they function as springs, and flow between the upper gas chamber, the lower gas chamber, and the reserve tank. The gas is throttled when passing through the first orifice mechanism, causing an energy loss, so that the gas also functions as a damper. In addition, the volume of the upper gas chamber and the lower gas chamber can be changed by injecting gas into the reserve tank or releasing gas from the reserve tank to increase or decrease the gas pressure in the reserve tank. , The vehicle height can be adjusted.
[0014]
The gas pressure in the reserve tank can be increased or decreased by connecting a separately prepared gas tank to the reserve tank only when necessary.However, there is an open / close valve for communicating with the reserve tank and adjusting the internal pressure. If a storage tank is provided in advance, opening and closing the on-off valve as necessary allows supply of gas from the storage tank into the reserve tank and discharge of gas from the reserve tank to easily adjust the vehicle height. It becomes possible.
[0015]
It is desirable that the first orifice mechanism has a function of adjusting the flow of gas flowing out of the gas chamber. With such a function, the damper function can be adjusted by setting the amount of attenuation when the gas in the gas chamber is compressed and flows out.
[0016]
Further, it is preferable that the first orifice mechanism includes a plurality of flow paths having different inner diameters, and the flow of the gas can be adjusted by selecting an arbitrary flow path from the plurality of flow paths. This makes it possible to adjust the flow of the gas flowing from the gas chamber into the reserve tank simply by selecting a flow path corresponding to a plurality of preset flow rates, thereby facilitating the adjustment of the attenuation.
[0017]
By providing a second orifice mechanism for communicating the atmosphere and the intermediate gas chamber which is partitioned between the inner cylinder piston and the outer cylinder piston, the gas of the intermediate gas chamber subjected to any load to the outer cylinder and the inner cylinder When compressed, the gas is released to the atmosphere through the second orifice mechanism. Conversely, when the load is reduced or released and the gas pressure in the intermediate gas chamber is reduced, the gas in the atmosphere is reduced to the second orifice mechanism. Through the intermediate gas chamber.
[0018]
As described above, the gas flowing through the intermediate gas chamber and the atmosphere is throttled when passing through the second orifice mechanism, causing an energy loss. Therefore, the function as a damper is further improved and the shock load is buffered. Functions are also improved.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a schematic configuration diagram showing a suspension device according to an embodiment, FIG. 2 is a longitudinal sectional view of the air suspension main body shown in FIG. 1, FIG. 3 is a partially enlarged view of the air suspension main body shown in FIG. ) Is a plan view of the flow path switching valve, FIG. 5B is a side view of the flow path switching valve, FIG. 5C is a bottom view of the flow path switching valve, and FIG. 5 is a portion of the air suspension main body shown in FIG. It is an enlarged view.
[0020]
As shown in FIG. 1, the suspension device according to the present embodiment includes an air suspension body 10 that suspends a wheel-side member L and a vehicle-body-side member U, which are constituted by a knuckle, an upper arm, a lower arm, and the like so that the wheel T can rotate. A reserve tank 3 that communicates with the air suspension body 10 via a first orifice mechanism 1 described later, and a storage tank 5 for internal pressure adjustment that communicates with the reserve tank 3 via a pressure control valve 4. . The air suspension body 10 is connected to the wheel-side member U by an upper mount 22 provided at the upper end of an external cylinder 13 described later, and connected to the wheel-side member L by a rod 23 provided at the lower end of the lower cylinder 16. ing.
[0021]
As shown in FIG. 2, the air suspension body 10 includes an outer cylinder 13 having an upper end closed by a cap 11 and an upper lid 12, and a cylindrical body having an outer diameter smaller than the inner diameter of the outer cylinder 13. An inner cylinder 16 in which a lower end is closed by a lower lid 14 and an upper end is closed by an outer cylinder piston 15 and the outer cylinder piston 15 is disposed in airtight sliding contact with the inner peripheral surface 13 a of the outer cylinder 13. And a piston shaft 17 which penetrates the outer cylinder piston 15 in an airtight and slidable manner and has an upper end portion 17a fixed to the upper lid body 12, and an inner cylinder 16 fixed to the lower end portion 17b of the piston shaft 17 And an inner cylinder piston 18 slidably disposed on the inner peripheral surface 16a of the inner cylinder.
[0022]
Further, a flow path 21 communicating between a lower gas chamber 19 divided by the lower lid 14 and the inner cylinder piston 18 and an upper gas chamber 20 divided by the upper lid 12 and the outer cylinder piston 15 is formed. The upper end of the flow path 21 formed in the piston shaft 17 is connected to the reserve tank 3 via the first orifice mechanism 1. Further, a second orifice mechanism 30 is provided for communicating the atmosphere with an intermediate gas chamber 29 divided by the inner cylinder piston 18 and the outer cylinder piston 15.
[0023]
As shown in FIG. 3, the first orifice mechanism 1 includes flow paths 31 and 25 formed linearly upward from the flow path 21 and a flow path 33 that bypasses the flow path 31. A check valve 36 including a spring 34, a spring support 34 a having a smaller inside diameter than the flow path 31, and a check ball 35 urged toward the flow path 21 by the spring 34 is provided in the middle. Between the check valve 36 and the flow path 21, a flow path 31 a having a smaller inner diameter than the flow path 31 is formed by reducing the diameter of the flow path 31 in a funnel shape.
[0024]
The flow path 33 is formed so as to bypass the check valve 36 from a portion closer to the flow path 21 than the check valve 36 toward the reserve tank 3. Above the check valve 36, the flow path switching valve 24 that joins the flow path 33 and the spring support portion 34a is arranged.
[0025]
As shown in FIG. 4, the flow path switching valve 24 includes a flow path 25 penetrating vertically through the center thereof and communicating with the spring support portion 34a, and six flow paths 26a which are collected in the flow path 25 and have different inner diameters. 26b, 26c, 26d, 26e, and 26f. The inner diameters of the flow paths 26a to 26f are all smaller than the inner diameter of the flow path 33. The head of the flow path switching valve 24 is a hexagonal nut-shaped dial, and openings of the flow paths 26a to 26f are formed at positions corresponding to the six surfaces of the hexagonal nut.
[0026]
By rotating the flow path switching valve 24 about the flow path 25, any one of the six flow paths 26a to 26f is connected to the flow path 33. By selecting a path, the flow of gas passing through the flow path 33 can be adjusted. Markers 28 indicating the inner diameters of the six flow paths 26a to 26f are displayed on the six surfaces on the outer periphery of the head 27, and by positioning these markers 28 toward the flow path 33, An arbitrary flow path can be easily selected from the two flow paths 26a to 26f.
[0027]
As shown in FIG. 5, the second orifice mechanism 30 includes a vent 37 formed near the lower end of the outer cylinder 13, a vent 38 formed near the upper end of the inner cylinder 16, The airtight seal member 39 is attached to the lower end portion, and is constituted by a flow path 40 formed in a gap between the outer cylinder 13 and the inner cylinder 16, and communicates the intermediate gas chamber 29 with the atmosphere.
[0028]
In a normal use state of the suspension device such as when the vehicle is running, the pressure regulating valve 4 is closed, and the gas supplied from the storage tank 5 is sealed in the reserve tank 3 and the upper gas chamber 20 and the lower gas chamber 19. And In such a state, the gas as a whole is sealed in the reserve tank 3, the upper gas chamber 20, and the lower gas chamber 19, so that it functions as an air spring against a load applied to the air suspension body 10. I do.
[0029]
In this case, since the air suspension function is exerted by the gas pressure sealed in the two gas chambers of the upper gas chamber 20 and the lower gas chamber 19, the load resistance is 1.5 to 2 times that of the conventional air suspension. Become. Therefore, it is possible to increase the load resistance while avoiding an increase in the size of the device.
[0030]
Further, since the lower gas chamber 19 and the upper gas chamber 20 are communicated with each other by the flow path 21 in the piston shaft 17, the gas pressure in the upper gas chamber 20 is always equal to the gas pressure in the lower gas chamber 19. And the applied load is evenly distributed by the gas in the upper gas chamber 20 and the lower gas chamber 19, so that it is possible to prevent the adverse effects due to the concentrated load on one of the gas chambers, and to achieve a smooth suspension. The function is obtained.
[0031]
Next, an operation state of the suspension device will be described with reference to FIGS. 6 is a longitudinal sectional view showing a compression operation state of the air suspension body shown in FIG. 1, FIG. 7 is a partially enlarged view of FIG. 6, FIG. 8 is a longitudinal sectional view showing an extension operation state of the air suspension body shown in FIG. FIG. 9 is a partially enlarged view of FIG.
[0032]
When a vertical vibration or a load due to a roll is applied to the air suspension main body 10 during running of the vehicle, the outer cylinder piston 15 moves in a direction away from the inner cylinder piston 18 as shown in FIG. The gas in the upper gas chamber 20 is compressed, and this gas flows into the reserve tank 3 via the flow path 21 and the first orifice mechanism 1 and the like. At this time, as shown in FIG. 7, the check ball 35 rises against the urging force of the spring 34 due to the gas flow flowing from the flow path 21 and the check valve 36 is opened, so that the gas flow is After passing through the flow paths 31a and 31 and the spring support portion 34a without passing through the small flow path 26a, it flows into the reserve tank 3 via the flow path 25. Since the inner diameter of the flow path 31a is smaller than the inner diameter of the flow path 21, when flowing from the flow path 21 to the flow path 31a, the gas flow is throttled, the flow velocity changes rapidly, and the flow energy is lost. Function is exhibited.
[0033]
Further, when the gas in the lower gas chamber 19 and the gas in the upper gas chamber 20 are compressed by the load applied to the air suspension main body 10, the volume of the intermediate gas chamber 29 increases, the internal pressure decreases, and air in the atmosphere is reduced. The air flows into the intermediate gas chamber 29 via the second orifice mechanism 30 constituted by the ventilation holes 37 and 38 and the flow path 40. When the airflow passes through the second orifice mechanism 30, the airflow is restricted. As a result, the flow velocity changes abruptly and the flow energy is lost, so that the function as a damper is exhibited.
[0034]
On the other hand, when the load applied to the air suspension main body 10 is reduced or released, the outer cylinder piston 15 moves in a direction approaching the inner cylinder piston 18 as shown in FIG. The internal pressure of the chamber 20 decreases, and the gas in the reserve tank 3 flows into the lower gas chamber 19 and the upper gas chamber 20 via the first orifice mechanism 1. At this time, as shown in FIG. 9, since the check ball 35 is urged by the spring 34 and the check valve 36 is closed, the gas flow passes through the flow path 25 and then passes through the flow path 26a of the flow path switching valve 24. Then, the gas flows into the flow path 33 bypassing the flow path 31 and flows into the upper gas chamber 20 and the lower gas chamber 19 via the flow path 21. Since the inner diameters of the flow paths 26a to 26f are all smaller than the inner diameter of the flow path 25, when flowing into the flow path 26a from the flow path 25, the gas flow is restricted, the flow velocity changes rapidly, and the loss of the flow energy is reduced. The function as a damper is exhibited by the occurrence.
[0035]
The adjustment of the damper function can be performed by selecting one of the flow paths 26a to 26f by the flow path switching valve 24. Also, when the outer cylinder piston 15 moves in the direction approaching the inner cylinder piston 18 due to the reduction or release of the load, the volume of the intermediate gas chamber 29 decreases, the internal pressure increases, and the internal air is vented. The air is discharged to the atmosphere via the second orifice mechanism 30 constituted by the 37 and 38 and the flow path 40. However, when the air flow passes through the second orifice mechanism 30, a loss of flow energy occurs, and as a damper, The function of is exhibited.
[0036]
Further, in the suspension device of the present embodiment, the gas filled in the storage tank 5 is supplied into the reserve tank 3 via the pressure regulating valve 4 to increase the internal pressure or to remove the gas in the reserve tank 3. It can be released into the atmosphere to reduce internal pressure. Therefore, by increasing and decreasing the internal pressure of the reserve tank 3 and increasing and decreasing the internal pressure of the upper gas chamber 20 and the lower gas chamber 19 that are communicated with the reserve tank 3, the stationary positions of the outer cylinder piston 15 and the inner cylinder piston 18 are increased. Can be changed, so that the vehicle height can be adjusted.
[0037]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0038]
(1) An air suspension device includes an outer cylinder in which one end of a tubular body is closed by an upper lid, and a base end of the tubular body having an outer diameter smaller than the inner diameter of the tubular body. An inner cylinder in which the outer cylinder piston is air-tightly slid on the inner peripheral surface of the outer cylinder, and the outer cylinder piston is hermetically sealed with the lid closed and the other end closed by the outer cylinder piston A piston shaft pierced slidably and having its base end fixed to the upper lid, and an inner cylinder piston fixed to the piston shaft and slidably disposed on the inner peripheral surface of the inner cylinder. With this arrangement, the outer cylinder and the inner cylinder are arranged in a nested manner, between the outer cylinder piston and the upper lid, and between the inner cylinder piston and the bottom lid, respectively. Scale by relative reciprocating sliding motion of -Tight gas chamber is formed, since the air suspension function with a gas pressure which is sealed in these two gas chamber is exerted, while avoiding an increase in size of the apparatus, it is possible to increase the load-bearing.
[0039]
(2) A gas passage that communicates the lower gas chamber divided by the bottom lid and the inner cylinder piston and the upper gas chamber divided by the upper lid and the outer cylinder piston member is formed by a piston shaft. The gas pressure in the upper gas chamber and the gas pressure in the lower gas chamber are always kept equal, and the applied load is equalized by the gas in the upper and lower gas chambers. Therefore, it is possible to prevent adverse effects due to the concentrated load on one of the gas chambers, and to obtain a smooth suspension function.
[0040]
(3) Since the gas in the upper gas chamber, the lower gas chamber, and the gas in the reserve tank are entirely sealed by providing the gas flow path with the reserve tank communicated via the first orifice mechanism, the gas spring is used as an air spring. The gas flowing between the upper gas chamber and the lower gas chamber and the reserve tank is throttled when passing through the first orifice mechanism, causing an energy loss, and thus also functions as a damper. I do. In addition, the height of the vehicle can be adjusted by increasing and decreasing the gas pressure in the reserve tank by injecting and discharging gas, and changing the volumes of the upper gas chamber and the lower gas chamber.
[0041]
(4) By providing the second orifice mechanism for communicating the intermediate gas chamber and the atmosphere, which is partitioned between the inner cylinder piston and the outer cylinder piston, gas flowing between the intermediate gas chamber and atmosphere Is narrowed when passing through the second orifice mechanism, causing an energy loss. Therefore, the function as a damper is further improved, and the function of buffering an impact load is also improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a suspension device according to an embodiment.
FIG. 2 is a longitudinal sectional view of the air suspension main body shown in FIG.
FIG. 3 is a partially enlarged view of the air suspension main body shown in FIG. 2;
4A is a plan view of a flow path switching valve, FIG. 4B is a side view of the flow path switching valve, and FIG. 4C is a bottom view of the flow path switching valve.
FIG. 5 is a partially enlarged view of the air suspension main body shown in FIG. 2;
6 is an explanatory longitudinal sectional view showing a compression operation state of the air suspension main body shown in FIG. 1;
FIG. 7 is a partially enlarged view of the air suspension main body shown in FIG. 6;
FIG. 8 is an explanatory longitudinal sectional view showing an extension operation state of the air suspension body shown in FIG. 1;
9 is a partially enlarged view of the air suspension main body shown in FIG.
FIG. 10 is a schematic configuration diagram of a conventional vehicle height-adjustable suspension device.
11 is an air system diagram of the vehicle height-adjustable suspension device shown in FIG.
[Explanation of symbols]
Reference Signs List 1 First orifice mechanism 3 Reserve tank 4 Pressure regulating valve 5 Storage tank 10 Air suspension body 11 Cap 12 Upper lid 13 External cylinders 13a, 16a Inner peripheral surface 14 Lower lid 15 Piston for outer cylinder 16 Internal cylinder 17 Piston shaft 17a Upper end portion 17b Lower end portion 18 Inner cylinder piston 19 Lower gas chamber 20 Upper gas chambers 21, 25, 31, 31a, 33, 26a to 26f, 40 Flow path 22 Upper mount 23 Rod 24 Flow path switching valve 27 Head 28 Marker 29 Intermediate gas chamber 30 Second orifice mechanism 34 Spring 34a Spring support 35 Check ball 36 Check valve 37, 38 Vent 39 Airtight seal T Wheel U Body side member L Wheel side member

Claims (1)

An outer cylinder in which one end of the cylindrical body is closed by an upper lid, and a base end of the cylindrical body having an outer diameter smaller than the inner diameter of the cylindrical body closed by a bottom lid and the other end thereof And an inner cylinder in which the outer cylinder piston is airtightly slid on the outer peripheral surface of the outer cylinder in a shape in which the outer cylinder piston is closed with an outer cylinder piston, and the outer cylinder piston is airtight and slidable. A piston shaft fixed to the upper lid body and penetrating the base end thereof, and an inner cylinder piston fixed to the piston shaft and slidably disposed on the inner peripheral surface of the internal cylinder,
A gas flow path communicating the lower gas chamber divided by the bottom lid and the inner cylinder piston and the upper gas chamber divided by the upper lid and the outer cylinder piston is formed in the piston shaft. Formed into
A reserve tank that communicates with the gas flow path via a first orifice mechanism;
A vent formed near the lower end of the outer cylinder, a vent formed near the upper end of the inner cylinder, and a hermetic seal material attached to the lower end of the outer cylinder allow the outer cylinder and the inner cylinder to be mounted. A gas passage formed in a gap between the cylinder and a cylinder, and an intermediate gas chamber and an atmosphere separated from the upper gas chamber and the lower gas chamber by the inner cylinder piston and the outer cylinder piston in a non-communicating state. A suspension device provided with a second orifice mechanism that communicates with the suspension.

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