JP3797452B2 - Air spring suspension mechanism for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air spring type suspension mechanism for a vehicle in which a reference vehicle height is lowered in accordance with an increase in vehicle body load, and the heights of front and rear shafts are made substantially equal to improve running stability.
[0002]
[Prior art]
In a normal vehicle having a leaf spring type suspension mechanism, for example, which is different from the air spring type suspension mechanism, the plate spring of the plate spring type suspension mechanism bends according to the weight when the vehicle is loaded and the vehicle height is lowered. In other words, the center of gravity decreases as the load or vehicle load increases, so that the stability of the vehicle increases. However, in the air spring type suspension mechanism, when the lever of the vehicle height adjustment valve tilts upward or downward from the horizontal position in relation to the relative displacement between the vehicle body and the axle, one of the air supply valve and the exhaust valve opens, and the air spring The amount of air is adjusted so that the vehicle height remains constant regardless of whether the vehicle is empty or loaded. In general, the air spring type suspension mechanism is employed to improve the riding comfort, and has a smaller spring constant and a larger roll amount during turning while compared with a normal plate spring type suspension mechanism. In particular, when an air spring type suspension mechanism having a vehicle height adjusting valve is adopted for a vehicle having a high vehicle height such as RV, the center of gravity does not change even when the vehicle body load on one side is increased when turning in a loaded state. As a result, the roll amount increases and the stability of the vehicle may be impaired.
[0003]
Since the spring constant of the air spring has a characteristic that is inversely proportional to the capacity of the air spring, it is desirable that the vehicle height be lowered in the case of a loaded vehicle in order to achieve both vehicle running stability and ride comfort. In such a case, it is conceivable to lock the air spring by locking the operation of the vehicle height adjustment valve so that the air amount of the air spring does not change. However, the vehicle height due to air leakage (internal pressure) or temperature change can be considered. A means to prevent change is needed.
[0004]
In the air spring suspension mechanism disclosed in Japanese Utility Model Publication No. 4-98604, the length of the link connecting the axle case and the lever of the vehicle height adjustment valve is changed by a manual operation lever when loading and unloading. By doing so, the height of the loading platform can be adjusted to the same height as the platform. However, the above-described air spring type suspension mechanism cannot adjust the vehicle height according to the vehicle body load while the vehicle is running.
[0005]
[Problems to be solved by the invention]
In view of the above-mentioned problems, the object of the present invention is not only to reproduce normal operation as an air spring type suspension mechanism, but also to automatically lower the vehicle height in accordance with an increase in vehicle body load and to improve running stability. Another object of the present invention is to provide an air spring type suspension mechanism for a vehicle.
[0006]
Another object of the present invention is to provide a vehicle air spring system that does not require a sub-air tank or complicated control, and balances the vehicle heights of the respective wheels corresponding to the loaded vehicle, thereby improving running stability. It is to provide a suspension mechanism.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the configuration of the present invention is such that a vehicle height adjusting valve is connected in the middle of a pipe connecting an air tank and an air spring, and the vehicle height adjustment is carried out on a control lever that is supported by a shaft horizontally and tiltably. The valve is fixedly supported, the tip of the lever of the vehicle height adjusting valve and the suspension arm are connected by a link, and the rod of a pneumatic actuator supported below the control lever of the vehicle body is connected to the control lever, and the actuator When the end of the control lever is pushed up against the spring force by the rod of the actuator in response to an increase in air pressure of the air spring, the vehicle height adjusting valve is connected to the air chamber of the air spring. The tip of the lever is inclined downward and the target vehicle height is set low.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, mainly when the vehicle is stopped, the air of the air spring is discharged from the vehicle height adjusting valve in accordance with the magnitude of the vehicle body load, and the vehicle height is lowered. For this reason, by pushing up the control lever that holds the vehicle height adjustment valve according to the increase in air pressure (internal pressure) of the air spring by the actuator, the air amount of the air spring is reduced without impairing the function of the vehicle height adjustment valve, Vehicle height can be lowered.
[0010]
However, if the vehicle height adjustment is controlled only for each wheel, there is a risk that the vehicle body may tilt if the load position of the load is biased in the case of a cargo vehicle. In the present invention, the actuator of each wheel is operated using the air pressure of one air spring to suppress the front / rear / left / right inclination. For example, in an air spring type suspension mechanism for a rear wheel, an actuator equipped with a spring opposite to the air pressure of the rear wheel air spring that maintains a balance with a standard load can be used to adjust the vehicle height adjustment valve mounting base according to changes in wheel load. Rotate to adjust the vehicle height. A stopper is provided inside the air spring so that the vehicle height does not become higher than necessary even if the air pressure of the air spring falls.
During normal driving, if the control lever that holds the vehicle height adjustment valve is locked, the vehicle height adjustment valve swings according to the vertical movement of the vehicle body due to changes in the road surface, and the air is adjusted to adjust the vehicle height. Adjust the amount of spring air.
[0011]
【Example】
As shown in FIG. 1, according to the present invention, a vehicle height adjustment valve 12a fixed to a conventional vehicle body is moved up and down by using the air pressure of the air spring 6, so that the air spring 6 does not depend on the actual vehicle height. The air amount of the air spring 6 is adjusted according to the air pressure of the vehicle, that is, the vehicle body load. The air spring 6 has an upper end coupled to the vehicle body 4, and a rod 6 a protruding downward is coupled to the suspension arm 22 by a pin 21. The suspension arm 22 is supported by the vehicle body 4 at the base end so as to be swingable by the support shaft 24, and the tip end is connected to a nut supporting the wheel 7. A vehicle height adjusting valve 12a is fixed to a control lever 26 that is rotatably supported on the vehicle body 4 by a support shaft 28. When the lever 8 tilts upward or downward about the shaft 8a, the operation of the vehicle height adjusting valve 12a is switched from the neutral position. The tip of the lever 8 is connected to the upper end of the link 23 by a pin 23a, and the lower end of the link 23 is connected to the suspension arm 22 by a pin 23b.
[0017]
In order to control the tilt of the control lever 26, a balancing cylinder or actuator A is connected between the control lever 26 and the vehicle body 4. The actuator A has a piston 33 inserted into a cylinder 31, an air chamber is formed on the upper side, and a working chamber 34 is formed on the lower side. The cylinder 31 is connected to the vehicle body 4 by a pin 40 (see FIG. 2). A rod 29 protruding upward from 33 is connected to the end of the control lever 26 by a pin 27. A spring 30 is housed in the atmospheric chamber of the cylinder 31, and a stopper 32 that regulates the upper limit position of the piston 33 and a stopper 32 a that adjusts the lower limit position with a screw are provided inside the cylinder 31.
[0018]
When the air pressure of the air spring 6 rises, the air pressure of the air spring 6 acts on the piston 33 from the working chamber 34 of the actuator A through the pipe 15a and the throttle 36. The piston 33 rotates the control lever 26 clockwise about the support shaft 28 against the force of the spring 30. Since the position of the vehicle height adjusting valve 12a is increased, the lever 8 of the vehicle height adjusting valve 12a is rotated counterclockwise about the shaft 8a, and the same conditions as when the vehicle height is increased are the same. The air of the air spring 6 is discharged, and the vehicle height is lowered. The throttle 36 provided in the pipe 15a suppresses a sudden change in the air pressure of the air spring 6 from acting on the working chamber 34. On the contrary, when the lever 8 is rotated clockwise around the shaft 8a, the pressurized air in the air tank 14 passes through the flexible pipe 13, the vehicle height adjusting valve 12a, and the flexible pipe 13a. Supplied to the spring 6 increases the vehicle height. Even if the end of the control lever 26 is pushed up manually for loading and unloading, the vehicle height can be lowered.
[0019]
In the partially modified embodiment shown in FIG. 2, a spring force adjusting mechanism is provided in the actuator A so that the balance of the vehicle height adjusting valves 12a of the left and right wheels 7 can be adjusted manually. The actuator A has a piston 33 inserted into a cylinder 31, an air chamber is formed on the upper side, and a working chamber 34 is formed on the lower side. The cylinder 31 is connected to the vehicle body 4 by a pin 40 and protrudes upward from the piston 33. The rod 29 is connected to the end of the control lever 26 by a pin 27. A stopper 32 for restricting the upper limit position of the piston 33 is disposed in the atmospheric chamber. A hollow bolt 37 integral with the spring seat 41 is screwed onto the upper end wall of the cylinder 31, and the spring 30 is interposed between the spring seat 41 and the piston 33. A rod 29 for connecting the piston 33 and the control lever 26 penetrates the bolt 37 and protrudes to the outside. The rod 29 is divided into two parts and is connected by a turnbuckle 39 so as to extend and contract. A switching valve 36a is connected in the middle of a pipe 15a connecting the air spring 6 and the actuator A working chamber 34. The pipe 15a is closed while the vehicle is running, and a throttle is interposed when the vehicle is stopped. .
[0020]
The set load of the spring 30 of the actuator A of the left and right wheels 7 is adjusted by a bolt 37. At this time, the length of the rod 29 is adjusted so that the lever 8 becomes horizontal with a predetermined vehicle body load. The other structure is the same as that of the embodiment shown in FIG. 1, and the same effect can be obtained. In the above-described embodiment, the adjustment of the vehicle height is limited only when the vehicle is stopped, so that safety is improved.
[0021]
In the above-described embodiment, the standard vehicle height is maintained in normal traveling. However, when a load is loaded, the vehicle height adjusting valve is controlled according to the load, and the vehicle height is lowered to improve traveling stability. However, depending on the loading position of the load, only the vehicle height of the rear wheel or one side wheel is lowered, and the posture of the vehicle body may lean forward / backward or sideways, which may adversely affect running stability. is there.
[0022]
In the embodiment shown in FIG. 3, with respect to the air spring type suspension mechanism of the wheels 7 and 7A, the vehicle height is maintained so as to keep the vehicle height constant by supplying and discharging air inside the air springs 6 and 6A due to the vehicle height change. When the adjustment valve 12a is incorporated and the air pressure of one air spring 6, 6A becomes high, the mounting member of the vehicle height adjustment valve 12a, that is, the control lever 26 is moved to correct the vehicle height. That is, the vehicle height of the air spring of another (front wheel) is also controlled using the air pressure of one air spring (for example, the rear wheel).
[0023]
When the vehicle height adjusting valve 12a is fixed to the control lever 26 that is rotatably supported by the support shaft 28 on the vehicle body, and the lever 8 is tilted upward or downward, the operation of the vehicle height adjusting valve 12a is switched from the neutral position. The tip of the lever 8 is connected to a rod 6 a of an air spring 6 of, for example, a rear wheel (both left and right rear wheels), and the lower end of the rod 6 a is connected to an axle case or a suspension arm 22. In order to control the inclination of the control lever 26, the actuator A is connected between the control lever 26 and the vehicle body. Actuator A has a piston 33 inserted into a cylinder 31, an air chamber is formed on the upper side, and a working chamber 34 is formed on the lower side. The cylinder 31 is connected to the vehicle body 4 by a pin and protrudes upward from the piston 33. 29 is connected to the end of the control lever 26 by a pin. A spring 30 is housed in the atmospheric chamber of the cylinder 31, and a stopper 32 that restricts the upper limit position of the piston 33 and a stopper 32 a that restricts the lower limit position are provided inside the cylinder 31.
[0024]
Similarly, for example, the air spring 6A of the front wheel 7A (both left and right front wheels) is provided with a control lever 26, an actuator A1, and a vehicle height adjusting valve 12a. The air pressure of the air spring 6 is supplied to the actuator A and the working chamber 34 of the actuator A1 through the pipe 15a. The structure of each actuator A, A1 is the same as that shown in FIG.
[0025]
When the air pressure of the air spring 6 rises, the air pressure of the air spring 6 acts on the piston 33 from the working chamber of each actuator A, A1 through the pipe 15a and the throttle 36. The piston 33 rotates the control lever 26 clockwise about the support shaft 28 against the force of the spring 30. Since the position of the vehicle height adjusting valve 12a is increased and the lever 8 of the vehicle height adjusting valve 12a is rotated counterclockwise, the conditions are the same as when the vehicle height is increased. 6A of air is discharged and the vehicle height is lowered. Since each actuator A, A1 operates according to the air pressure of the air spring 6, the spring load of the spring 30 of each actuator A, A1 corresponding to the load change received by the rear wheel 7 and the front wheel 7A depending on the load state of the load. Is set in advance, the balance between the front and rear wheels is obtained, and the vehicle body does not tilt excessively. The throttle 36 provided in the pipe 15a suppresses a sudden change in the air pressure of the air springs 6 and 6A from acting on the working chambers of the actuators A and A1.
[0026]
On the contrary, the lever 8 is rotated in the clockwise direction when the empty vehicle or the load is small, and the pressurized air in the air tank 14 is flexible tube 13, vehicle height adjustment valve 12 a, flexible Although it is supplied to the air springs 6 and 6A through the pipe 13a and the vehicle height increases, the vehicle body does not tilt extremely forward and backward.
[0027]
【The invention's effect】
In the present invention, as described above, a vehicle height adjusting valve is connected in the middle of a pipe connecting the air tank and the air spring, and the vehicle height adjusting valve is fixedly supported by a control lever that is supported by the vehicle body horizontally and tiltably. The lever tip of the vehicle height adjusting valve and the suspension arm are connected by a link , the rod of the pneumatic actuator supported below the control lever of the vehicle body is connected to the control lever, and the working chamber of the actuator is air When the end of the control lever is pushed up against the spring force by the rod of the actuator according to the increase in the air pressure of the air spring, the tip of the lever of the vehicle height adjusting valve is connected to the spring air chamber. Since the target vehicle height is set to be low and the target vehicle height is set low, the end of the lever of the vehicle height adjustment valve tilts downward as the vehicle height adjustment valve moves upward, and the air spring Sky There is discharged from the vehicle height adjusting valve, the vehicle height is automatically reduced, the running stability is improved.
[0029]
If the vehicle height adjustment valve is moved by the actuator of each wheel using the air pressure of one air spring, even if the loading position is deviated, the deviation of the vehicle height of the front and rear wheels or the left and right wheels is eliminated.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an air spring type suspension mechanism for a vehicle according to an embodiment of the present invention.
FIG. 2 is a side cross-sectional view of an actuator according to a partially modified embodiment of the air spring suspension mechanism.
FIG. 3 is a side sectional view of an air spring type suspension mechanism for a vehicle according to a modified embodiment of the present invention.
[Explanation of symbols]
A, A1: Actuator 2: Electronic control unit 3: Vehicle height sensor 4: Vehicle body 5: Air pressure sensor 6, 6A: Air spring 6a: Rod 7: Wheel 8: Lever 8a: Shaft 10: Pipe 12: Supply / exhaust valve 12a: Vehicle height adjustment valve 13: Pipe 14: Air tank 22: Suspension arm 23: Link 24: Support shaft 26: Control lever 28: Support shaft 29: Rod 30: Spring 31: Cylinder 32, 32a: Stopper 33: Piston 34: Actuation Chamber 36: Restriction 36a: Switching valve 37: Bolt 39: Turnbuckle 41: Spring seat

Claims (1)

Connect the vehicle height control valve in the middle of the tube connecting the air tank and the air spring, the vehicle height control valve fixedly supported to the horizontal and tiltable control lever which is axially supported on the vehicle body, the lever of the vehicle height control valve The tip of the vehicle and the suspension arm are connected by a link, the rod of the pneumatic actuator supported below the control lever of the vehicle body is connected to the control lever, and the actuator operating chamber is connected to the air chamber of the air spring. When the end of the control lever is pushed up against the spring force by the rod of the actuator in response to an increase in the air pressure of the air spring, the tip of the lever of the vehicle height adjusting valve tilts downward, and the actual vehicle An air spring suspension system for a vehicle, characterized in that the height is set low.

Images