JPS6146329B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure regulating device for an air spring for a vehicle, which adjusts the vehicle height by controlling the air pressure of the air spring.

The ground clearance of a vehicle changes depending on the load and the number of passengers, and the change is particularly large for small vehicles such as motorcycles. Therefore, some vehicles combine an air spring with a damper and adjust the vehicle height using the air pressure of the air spring. In this case, the air pressure in the front wheels and the air pressure in the rear wheels are different, so it is necessary to adjust the air pressures for the front and rear wheels separately. Therefore, the air pressure of the front wheel air spring and the air pressure of the rear wheel air spring had to be detected by separate pressure sensors.

However, in vehicles such as motorcycles where the loading space for parts is severely limited, only one pressure sensor is required.
It is desirable to simplify piping and control.

However, when controlling the air pressure using one pressure sensor in this manner, the pressure sensor must be provided at a position far from the air spring, that is, at a position close to the air pump. For this reason, it becomes extremely difficult to accurately adjust the air pressure of the air spring to the target air pressure due to the passage resistance of the air passage and the relationship between the air chamber capacity of the air spring and the air passage volume. That is, when the air pressure is increased, a pressure difference occurs between the pressure sensor position and the air chamber of the air spring due to passage resistance.

The present invention was developed in view of the above circumstances, and makes it possible to control multiple air springs with one air pump, one pressure sensor, and one exhaust valve, thereby reducing the size and simplicity of the entire device. It is an object of the present invention to provide a pressure regulating device for an air spring for a vehicle, which is compact and lightweight, and can control the air pressure of the air spring with high precision.

In order to achieve this object, the present invention includes an air pump that forces air into an air chamber of an air spring, a control valve that opens and closes an air passage connecting this air pump and the air chamber, and this control valve and the air pump. and a control device that controls the air pump and the control valve, and the pressure sensor detects an increase in air pressure due to the operation of the air pump while the control valve is open. However, the air pump is stopped at the upper limit of the allowable variation range of the target air pressure, and the air pressure is stabilized at the target air pressure. The present invention will be explained in detail below based on the illustrated embodiments.

Fig. 1 is a partially cutaway side view of a motorcycle to which an embodiment of the present invention is applied, Fig. 2 is a diagram showing its air spring and its pressure regulating system, and Fig. 3 is a change in air pressure when pressurized. FIG. 3 is a diagram showing characteristics.

In FIG. 1, reference numeral 10 is a backbone type frame, and this frame 10 includes an engine 1.
2 is attached so that it hangs down. This engine 12 has two banks 1 tilting forward and backward.
4, 14, and carburetors 17, 17 are disposed between these two banks 14, 14. Reference numeral 18 denotes a rear wheel, which is held movably up and down by a rear arm 20 having a generally triangular side surface.

Reference numeral 22 designates an air spring for the rear wheel 18. One end of the spring 22 is pivoted to the upper apex 24 of the rear arm 20, and the other end is pivoted to a bracket fixed to the frame 10. 26 is a fuel tank located above the engine 12, 28 is an air spring 22
This is the seat located above the .

30 is a pair of left and right front forks (only one is shown), and upper and lower brackets 3
2 and 32, it is held by a head pipe located at the front end of the frame 10, and is rotatable left and right. The front fork 30 includes an inner tube 34 and an outer tube 36, and the tubes 34 and 36 are telescopically combined with each other, and a damper, a coil spring, and an air spring are incorporated therein. Left and right front forks 3
The air chambers forming the air spring in the front fork 30 are communicated with each other through a communication pipe (not shown) at the upper end of the front fork 30. Reference numeral 38 in the figure is a communication pipe that connects both air chambers to a control valve 90 described later.

40 is a front wheel held at the lower end of the fork 30. Further, a pressure regulating device for controlling air pressure is provided below the air spring 22 for the rear wheel 18.

Here, the air spring 22 will be explained with reference to FIG. In this figure, 42 is a hydraulic damper, which includes a cylinder 44 and a free piston 48 that forms a gas chamber 46 at the bottom of the cylinder 44 (on the right end side in the figure).
, a piston 54 defining two oil chambers 50 and 52 within the cylinder 44, and a rod 56 having one end fixed to the piston 54. piston 5
A plurality of throttle holes 58 are formed in the oil chamber 4 to connect the oil chambers 50 and 52. Also, a bracket 60 is fixed to the other end of the rod 56, and a bracket 60 is attached to surround the left end of the rod 56 and the cylinder 44.
An air chamber 66 is formed by the tube 62 fixed at 0, and a flexible seal member 64 that airtightly connects the left end of the cylinder 44 and the right end of the tube 62. A communication pipe 68 communicating with an air chamber 66 is connected to the bracket 60.

70 is a coil spring, one end of which is locked to a spring seat 72 fixed to the cylinder 44, and the other end is locked to a cover 74 that extends from the tube 62 and covers the outer periphery of the seal member 64 and is close to the cylinder 44. .

Next, the pressure regulating device will be explained. 1 and 2, 80 is an electric motor, 82 is an air pump driven by this electric motor 80, 84 is a filter through which air sucked into this pump 82 passes, and 85 and 86 are this pump 8.
2 is a dehumidifier and one-way valve through which discharged air passes.

88 is a control valve that opens and closes an air passage connecting this one-way valve 86 and the air chamber 66 of the air spring 22;
90 also has one-way valve 86 and front fork 3
This is a control valve that opens and closes the air passage that connects the air chamber in the air chamber. Those control valves 88, 90 and one-way valve 8
6, one pressure sensor 92 and one exhaust valve 94 are connected. Note that the control valve 88,
The exhaust valve 90 and the exhaust valve 94 are of a two-port, two-position, spring-offset, electromagnetic type, and return to a position that closes the air passage when the solenoid is not energized.

A control device 96 controls the valves 88, 90, 94 and the electric motor 80 based on a signal p indicating the pressure output by the pressure sensor 92 and commands from an operation panel (not shown). This control device 96 controls the upper limit Ph of the permissible fluctuation range of the target air pressure PO during pressurization.
The electric motor 80 is stopped at the target air pressure PO.
It operates to stabilize air pressure.

Next, the operation of this embodiment will be explained. Figure 3 shows
It is a figure which shows the change of the air pressure P detected by the pressure sensor 92 at the time of pressurization. First, a case will be described in which the air chamber 66 of the air spring 22 for the rear wheel 18 is pressurized.
Control valve 88 opens based on a command from the operation panel, and electric motor 80 starts rotating. Since the pressurized air flows into the air chamber 66 through the control valve 88, the pressure P detected by the sensor 92 also increases as shown in FIG. When the pressure P of the sensor 92 reaches the upper limit Ph of the permissible fluctuation range of the target air pressure PO, the control device 96 stops the electric motor 80 and maintains it in that state for a while. electric motor 80
During operation, resistance to flow through the air passage acts, so the detected pressure P of the sensor 92 is higher than the internal pressure of the air chamber 66. Therefore, when the electric motor 80 is stopped, the air pressure in the closed space formed by the air chamber 66, the air passage, and the one-way valve 86 is averaged. Therefore, the detected pressure P of the sensor 92 slightly drops from the upper limit Ph and stabilizes at the target air pressure PO. Controller 96 then closes control valve 88 . The target air pressure is selected by the operation panel, and the upper limit Ph of the allowable range is determined based on the air resistance between the sensor 92 and the air pressure 66, the volume ratio between the air passage downstream of the sensor 92 and the air chamber 66, etc. , should be determined.

When lowering the air pressure in the air chamber 66, the control device opens the control valve 88 and the exhaust valve 94 to bring the air pressure P to the desired level.

Note that the control valve 90, electric motor 80, and exhaust valve 94 may be controlled in exactly the same manner for the air spring in the front fork 30 for the front wheels 40, so the description thereof will not be repeated.

In this embodiment, the air spring 22 includes an air chamber 66;
Although the coil spring 70 and the damper 42 are provided, it goes without saying that the air spring in the present invention may be a pure air spring that does not include a coil spring or a damper.

Since the present invention controls the air pressure of a plurality of air springs with one sensor as described above, the overall configuration is simplified and the weight and size can be reduced. Furthermore, during pressurization, the pump is stopped at the upper limit of the permissible fluctuation range of the target air pressure, so that the internal pressure of the air chamber and the closed space of the air passage is then stabilized at the target air pressure, and the air chamber pressure can be accurately controlled.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of an application example of the present invention, Fig. 2 is a diagram showing its air spring and pressure regulating system, and Fig. 3 is a diagram showing changes in the pressure detected by the pressure sensor during pressurization. It is a diagram. 22...Air spring, 66...Air chamber, 82...
Air pump, 88, 90... Control valve, 92... Pressure sensor, PO... Target air pressure, Ph... Upper limit.

Claims (1)

[Claims] 1. An air pump that pressure-feeds air to the air chamber of the air spring, a control valve that opens and closes an air passage connecting this air pump and the air chamber, and one air pump provided between this control valve and the air pump. The control device includes a pressure sensor and a control device that controls the air pump and the control valve, and the pressure sensor detects an increase in air pressure due to the operation of the air pump while the control valve is open, and determines the range of allowable variation in target air pressure. A pressure regulating device for an air spring for a vehicle, characterized in that the air pump is stopped at an upper limit to stabilize the air pressure at a target air pressure.