JPS6146330B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air pressure measuring 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.

Therefore, it is conceivable to provide a control valve that opens and closes the air passage between the air pump and the air spring, and to provide one pressure sensor and one exhaust valve between the control valve and the air pump. However, in this case, when the control valve is opened to check the air pressure in the air spring with a pressure sensor, the air pressure in the air chamber changes when the air pressure difference between the downstream side (air spring and air chamber) and the upstream side of the control valve is large. There is a problem with doing so. That is, when the air pressure on the upstream side of the control valve is low, air flows backward from the air chamber, and conversely, when the air chamber pressure is low, air flows into the air chamber from the pump side. Therefore, if the air pressure is checked many times, the air chamber pressure changes and the spring characteristics also change, which is an inconvenience. Further, if the pressure difference between the upstream side and the downstream side of the control valve is large, there is also a problem that the measured value of the pressure sensor when the control valve is opened and closed tends to be inaccurate.

The present invention was developed in view of these circumstances, and it simplifies the entire device by making it possible to control the air pressure of multiple air springs with one air pump, one pressure sensor, and one exhaust valve. To provide an air pressure measuring device for an air spring for a vehicle, which is miniaturized and lightweight, and allows accurate pressure measurement with almost no change in air chamber pressure even when the air chamber pressure is measured with a pressure sensor. The purpose is to

In order to achieve this object, the present invention includes an air spring having an air chamber, an air pump that pumps air to the air chamber, a control valve that opens and closes an air passage connecting the air pump and the air chamber, and a control valve that opens and closes an air passage that connects the air pump and the air chamber. 1 pressure sensor installed between the valve and the air pump and 1
a control device for controlling the air pump, a control valve, and an exhaust valve; It was configured to keep the air pressure near the lower limit. 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, and FIG. 2 is a diagram showing an air spring and its pressure regulating system.

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 can be suspended. This engine 12 includes two banks 14, 14 tilting forward and backward;
A vaporizer 17, 17 is arranged between them. 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 18 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 .

Reference numeral 30 denotes a pair of left and right front forks (only one is shown in the figure), which are held on the head pipe located at the front end of the frame 10 by upper and lower brackets 32, 32, and are rotatable left and right. ing. This front fork 30 includes an inner tube 34 and an outer tube 36, both tubes 34 and 36 are combined to be extendable and retractable, and a damper, a coil spring, and an air spring are incorporated inside. The air chambers forming the air springs in the left and right front forks 30 are connected to each other by a communicating pipe (not shown) at the upper end of the forks 30.
It is communicated by. In the figure, 38 is a communication pipe connecting both air chambers and 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, a free piston 48 forming a gas chamber 46 at the bottom of the cylinder 44 (on the right side in the figure), two oil chambers 50 in the cylinder 44, 5
2 and a piston 54 defining the piston 54.
and a rod 56 having one end fixed to the rod 56. The piston 54 has a throttle hole 58 that connects the oil chambers 50 and 52.
are formed in multiple numbers. Also, a bracket 60 is fixed to the other end of the rod 56, a tube 62 is fixed to the bracket 60 so as to surround the outer left end of the rod 56 and the cylinder 44,
An air chamber 66 is formed by a flexible seal member 64 that airtightly connects the left end of tube 4 and the right end of tube 62 . A communication pipe 68 communicating with the 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 the discharged air passes. The dehumidifier 85 is loaded with known silica gel or the like.

88 and 90 are control valves. The control valve 88 opens and closes the air passage connecting the one-way valve 86 and the air chamber 66 of the air spring 22. Further, the control valve 90 similarly opens and closes the air passage connecting the one-way valve 86 and the air chamber in the front fork 30. These control valves 8
8 and 90 and the one-way valve 86, one pressure sensor 92 and one exhaust valve 94 are connected. Note that the control valves 88, 90 and the exhaust valve 94
is 2 ports, 2 positions, spring offset,
It is an electromagnetic type, and returns to the position where the air passage is closed when the solenoid is de-energized.

A control device 96 controls the valves 88, 90, 94 and the electric motor 80 based on the pressure signal p output by the pressure sensor 92 and commands from an operation panel (not shown). This control device also includes a control valve 8
Prior to opening of the control valve 88 or 90, the internal pressure of the air passage on the upstream side of the control valve 88 or 90 is maintained near the lower limit of the target air pressure of the air chamber 66 of the air spring 22 or the air chamber within the front fork 30. The electric motor 80 and exhaust valve 94 are controlled.

Next, the operation of this embodiment will be explained. When increasing the internal pressure of the air chamber 66 of the air spring 22 of the rear wheel 18, the control device 96 activates the electric motor 80 according to a command from the operation panel.
is activated, and the air pressure P on the upstream side of the control valve 88 increases. Sensor 92 detects this air pressure P and sends a pressure signal p to control device 96. When the air pressure P reaches the lower limit of the target air pressure PO of the air chamber 66, the control device 96 opens the control valve 88 to pressurize the air chamber 66. When the sensor 92 detects that the air chamber 66 has reached the target air pressure PO, the control device 96 stops the electric motor 80 and closes the control valve 88.

When reducing the pressure in the air chamber 66, the electric motor 80 is operated prior to opening the control valve 88, and the control valve 88 is opened.
8. Set the upstream air pressure to the lower limit of the target air pressure PO. Then, the control valve 88 is opened, and then the exhaust valve 94 is intermittently opened according to commands from the operation panel, and the sensor 2
The detected pressure P is set to the pressure to be finally reduced. Then, the control valve 88 may be closed.

By reducing the pressure difference between the upstream and downstream sides of the control valve 88 prior to the opening of the control valve 88 in this manner, sudden changes in the pressure measured by the sensor 92 are eliminated, thereby improving pressure measurement accuracy. can.

Also, when checking the air pressure P in the air chamber 66, the electric motor 8 controls the upstream pressure of the control valve 88 to the lower limit of the target air pressure PO based on the command from the operation panel.
0 or exhaust valve 94, then control valve 8
8 and read the air pressure P detected by the sensor 92 in that state.

As for the air spring in the front fork 30, the above description of the rear wheel air spring 22 applies as is, and the only difference is the target air pressure, so the description will not be repeated.

In this embodiment, the air spring 22 is a coil spring 7
Although the air spring according to the present invention is also provided with a damper 42, it goes without saying that the air spring in the present invention may be an air spring in a pure sense without having these coil springs or dampers.

As described above, the present invention controls the air pressure upstream of the control valve to be near the lower limit of the target air pressure in the air chamber in advance of opening the control valve, and then controls the control valve to open. Therefore, in the case of an air pressure check, since the amount of air passing through the control valve is small, air pressure fluctuations are small, and even if the air pressure check is repeated several times, the air pressure in the air chamber does not change significantly. Further, when checking the air pressure in the air chamber, there is no sudden change in the air pressure detected by the pressure sensor, so pressure measurement can be carried out smoothly and measurement accuracy can be improved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of an application example of the present invention, and FIG. 2 is a diagram showing its air spring and pressure regulating system. 22...Air spring, 66...Air chamber, 82...
Air pump, 88, 90...control valve, 92...pressure sensor, 94...exhaust valve.

Claims (1)

[Claims] 1. An air spring having an air chamber, an air pump that pumps air to the air chamber, a control valve that opens and closes an air passage connecting the air pump and the air chamber, and between the control valve and the air pump. one pressure sensor and one exhaust valve provided in the air pump, a control device for controlling the air pump, a control valve, and an exhaust valve, and prior to opening of the control valve, An air pressure setting device for an air spring for a vehicle, characterized in that the internal pressure of the air passage is maintained near the lower limit of the target air pressure of the air chamber.