JPH0459574B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an automatic adjustment device for the air pressure of a damper that constitutes a suspension system for a motorcycle, and the invention automatically compensates for changes in the characteristics of an air pressure detection device, and automatically adjusts the air pressure of a damper that constitutes a suspension system of a motorcycle. Moreover, the air pressure can be automatically and accurately adjusted to a predetermined air pressure at all times.

[Prior art and issues]

A semiconductor pressure sensor detects the air pressure in the front fork and rear shock absorber of a motorcycle, and if the detected pressure differs from a predetermined pressure, it is automatically corrected to maintain the predetermined damper characteristics. There is an automatic adjustment device for the air pressure of the damper (not a so-called conventionally known device). This conventional damper air pressure automatic adjustment device is connected to the air pump driven by a motor through a check valve to the front fork and rear wheel shock absorbers equipped with solenoid valves, and furthermore, the semiconductor pressure The sensor is connected to the solenoid valve for opening and closing the atmosphere side. Normally, each solenoid valve is opened and closed, and a semiconductor pressure sensor detects the air pressure in the front fork and rear wheel shock absorbers.It determines whether the pressure is within a predetermined pressure or not, and if it is lower than the predetermined pressure, the air pump is activated. Therefore, the pressure is increased, and when the pressure is higher than a predetermined pressure, the pressure is lowered using a solenoid valve for opening and closing on the atmosphere side. In the conventional damper air pressure automatic adjustment device described above, the pressure detection characteristics of the semiconductor pressure sensor change due to changes in external environmental conditions such as temperature, humidity, and atmospheric pressure, and changes in usage conditions such as the passage of service life. However, the problem is that the actual air pressure of the damper is not adjusted to a predetermined pressure because it is not constant, and it is also not adjusted to an arbitrary predetermined air pressure, so that the predetermined damper cushioning performance cannot be obtained. There is. That is, with respect to the ideal straight line A shown in FIG.
The pressure detection characteristics B of actual semiconductor pressure sensors differ greatly, and their zero point voltages also differ. The pressure sensing ability of the actual semiconductor pressure sensor is the line A above.
If there is a large deviation from the predetermined value, the error in the measured value by the semiconductor pressure sensor will be large, and the automatic adjustment of the damper air pressure based on the measured value with a large error will deviate greatly from the predetermined value. By significantly improving the quality of semiconductor pressure sensors, it is possible to reduce initial value variations (variations in characteristics at the time of shipment from the factory) and to somewhat reduce changes in the above characteristics during the service life. The cost is too high to be used in automatic damper air pressure adjustment devices. Furthermore, although it is possible to initially adjust initial variations, it is practically impossible to electrically adjust changes in the above-mentioned characteristics during the service period. Problems in adjusting the initial characteristics of a semiconductor pressure sensor include the problem of the slope of the characteristic line in pressure-voltage characteristics and the problem of zero point voltage. In motorcycle shock absorbers, the hardness of the shock absorber is changed by changing air pressure, and the pressure measurement range is wide. Therefore, the slope of the characteristic line in the pressure-voltage characteristics of a semiconductor pressure sensor is important. Furthermore, for semiconductor pressure sensors, it is relatively easy to adjust the slope of the characteristic line in the pressure-voltage characteristics. Therefore, if the shift in the zero point can be electrically compensated at all times, pressure can always be detected accurately regardless of the shift in the pressure detection characteristics of the semiconductor pressure sensor itself. Therefore, the present invention makes it possible to compensate for the zero point voltage of the characteristic line of a semiconductor pressure sensor and to constantly eliminate the difference caused by external factors, and uses an inexpensive semiconductor pressure sensor to provide a front fork and a front fork of a motorcycle with a simple configuration. The problem is to automatically adjust the air pressure of the rear wheel shock absorber to a predetermined pressure arbitrarily and accurately.

[Measures taken to solve the problem]

The solution of the present invention is based on the above-mentioned conventional automatic adjustment device for the air pressure of a damper of a shock absorber for a motorcycle, and is constituted by the following elements (a) to (d). (a) The passage opening/closing solenoid valves 18 and 29 connected to the air pump 28 via the check valve 24 are connected in parallel to the air spring of the front fork 10 of the front wheel and the air spring of the shock absorber of the rear wheel, respectively, Furthermore, a check valve, one semiconductor pressure sensor 34, and one atmospheric side opening/closing solenoid valve 32 are connected in series to one pipe 22 between the air pump 28 and the passage opening/closing solenoid valves 18, 20. Solenoid valve 18, 20, 3
2 is controlled by the control device 40; (b) a ROM storing a program for calculating the difference between the atmospheric pressure measurement value by the semiconductor pressure sensor and the damper air pressure measurement value; and the pressure by the semiconductor pressure sensor. (c) The control device is provided with a RAM that temporarily stores measurement signals and calculation results by the CPU. The difference between the measured value and the measured value of atmospheric pressure is calculated by the CPU in the control device; (d) The control device has a hard/soft switching mechanism for the front wheel air spring and the rear wheel air spring. Connected to the control panel.

[Effect]

First, the solenoid valves 18 and 20 are closed, and with the solenoid valve 32 open, the semiconductor pressure sensor 34 measures the atmospheric pressure at that time. This measurement is at atmospheric pressure
It is the sum of Pa and the error ΔP of the semiconductor pressure sensor, that is, Pa+ΔP. This is temporarily stored in the RAM. Next, close the solenoid valve 32 and close the solenoid valve 1.
8 is opened and the air pressure of the front fork 10 is measured by the semiconductor pressure sensor 34. This measured value is the sum of the air pressure Pf of the front fork 10 and the error ΔP of the semiconductor pressure sensor, that is, Pf+ΔP. The difference between these measured values is calculated by the CPU in the control device using a program stored in the ROM. This calculation is (Pf + ΔP) - (Pa + ΔP)
=Pf-Pa, this process eliminates the error ΔP of the semiconductor pressure sensor and determines the gauge pressure of the damper air pressure. Therefore, irrespective of the existence and size of the error ΔP of the semiconductor pressure sensor, the air pressure of the front fork 10 can be compared with the reference value of the front fork to determine whether the air pressure is high or low. The same applies to the measurement and determination of the air pressure of the rear wheel shock absorber. Whether the above air pressure matches the air pressure of the true front fork 10 is related to the accuracy of the slope of the pressure-voltage characteristic diagram of the semiconductor pressure sensor, but this slope can be easily determined with sufficient accuracy. Since the period can be adjusted, the calculated value,
A sufficiently accurate value can be obtained for Pf-Pa. Therefore, the front fork of a motorcycle,
The air pressure of the rear wheel shock absorber can be accurately adjusted and maintained at a predetermined pressure. Furthermore, regardless of changes in the external environment, the buffering characteristics of the front fork are maintained.
In addition, the shock absorbing characteristics of the rear wheel shock absorber can be set to any hardness or softness depending on the driving conditions using the operation panel 56.
Easy and accurate adjustment based on simple operation.

【Example】

Next, an embodiment will be described with reference to FIGS. 1, 2, 3, and 4. A front fork 10 that constitutes a front wheel suspension of a motorcycle, and a shock absorber 1 that constitutes a rear wheel suspension.
2 has an air chamber of an air spring in the upper part of each of them, and air supply pipes 14 and 16 are connected to these air chambers, respectively. These pipes 14, 16 are connected to an air pump via solenoid valves 18, 20, a check valve 24 and a pipe 22, and a dehumidifier 26 is provided between the air pump 28 and the check valve 24. There is. A pipe 30 whose one end is open to the atmosphere is connected to the pipe 22, and a solenoid valve 32 is interposed in the middle of this pipe 30. These solenoid valves 18, 23, 32
is controlled by a control device 40, and conditions, reference values, etc. of the control device are set by an operation panel 56. A semiconductor pressure sensor 34 is connected to the pipe 22 and its measurement signal is transmitted to a control device 40 . Information transmitted from the operation panel 56 and the semiconductor pressure sensor 34 to the control device is displayed on a display device 58 connected to the control device 40, so that various information can be visually confirmed. The control device 40 includes an A/D converter 42 and a ROM 4.
6, RAM50, CPU48, output interface 5
2. It has a drive circuit 54, and this A/D converter 42
A semiconductor pressure sensor 34 is connected to the A/D converter 42, ROM 46, RAM 50, CPU 48,
Output interfaces 52 are connected to each other by bus lines 44. Measurement signal A/D from semiconductor pressure sensor 34
converted into a digital signal by a converter 42;
Temporarily stored in RAM50. The ROM 46 stores a program for calculating the difference between the measured value of the atmospheric pressure detected by the semiconductor pressure sensor 34 and the measured value of the damper air pressure. The CPU 48 uses the data stored in the RAM 50 according to the above program to calculate the difference between the measured value of atmospheric pressure and the measured value of the damper air pressure, temporarily stores this in the RAM, and stores the calculated value and the ROM in the ROM. It compares it with the standard value, determines its height, and issues a command according to the determination result. The output interface 52 outputs control commands from the CPU to the drive circuit 54, and the drive circuit 54 selectively opens and closes the solenoid valves 18, 20, and 32 in response to signals from the output interface 52. An operation panel 56 connected to the control device 40 is provided with various operating means, such as a hard/soft air spring switching button, a front wheel air spring, and a rear wheel air spring switching button. When the ignition switch of the motorcycle is turned on, the solenoid valve 3 is activated by a signal from the control device 40.
2 opens to temporarily release the tube 22 to the atmosphere. Atmospheric pressure is measured by the semiconductor pressure sensor 34, converted into a digital signal by the A/D converter 42, and temporarily stored in the RAM 50. The measured values at this time are the atmospheric pressure value Pa and the measurement error ΔP of the semiconductor pressure sensor 34. Thereafter, in response to a signal from the control device 40, the solenoid valve 32 is closed and the solenoid valve 18 is opened to communicate the air chamber of the front fork 10 with the pipe 22. The air pressure in the air chamber of the front fork 10 is measured by the semiconductor sensor 34, converted into a digital signal by the A/D converter 42, and temporarily stored in the RAM 50. The measured value at this time is the pressure value in the air chamber of front fork 10.
Pf and the measurement error ΔP of the semiconductor pressure sensor 34. The CPU uses the program stored in the ROM to calculate the difference between the above two measured values, that is, (Pf + ΔP) -
Calculate (Pa+ΔP)=Pf−Pa. This calculated value excludes the zero point voltage of the semiconductor pressure sensor 34 and the measurement error ΔP due to external factors.
Compare this calculated value with the reference value of the front fork 10 stored in the ROM to determine its height,
Issues necessary commands according to the judgment results. This adjustment ends when the calculated value is equal to the reference value. When the calculated value is higher than the reference value, the solenoid valve 32 is opened to release the air in the air chamber of the front fork 10 to the atmosphere from the pipe 30, thereby reducing the air pressure in the air chamber to a predetermined value. When the calculated value is lower than the reference value, the motor 36 is started and the front fork 1
0 air chamber is filled with air and the air pressure is increased to a predetermined value. The pressure in the air chamber of the rear wheel shock absorber 12 is also adjusted in the same manner as described above. When the air pressure setting value of the front fork 10 and the air pressure setting value of the rear wheel shock absorber are made the same using the operation panel 56, the hardness of the front forks and the hardness of the rear wheel shock absorber become the same.

【effect】

The above-mentioned problem of the present invention in an air pressure adjustment device for a damper of a motorcycle is novel. Therefore, to solve this new problem, the air pressure of the damper can be automatically adjusted to a predetermined pressure simply, easily, and accurately without being affected by changes in the external environment.
Further, a unique effect of the present invention is that the hardness or softness of the damper can be adjusted arbitrarily and accurately to a predetermined state. The motorcycle damper air pressure adjustment device of the present invention does not require particularly high quality semiconductor pressure sensors, and the motorcycle damper air pressure adjustment device of the present invention has a simple configuration as described above, so manufacturing costs can be reduced. Can be reduced. Furthermore, a single conduit is created between the air pump and the solenoid valves for opening and closing the front and rear shock absorbers.
This is connected in series with a check valve, one semiconductor pressure sensor, and one solenoid valve for opening/closing the atmosphere side, and the solenoid valves for opening/closing the front and rear shock absorbers are connected in parallel to this conduit. Therefore, the hydraulic circuit is extremely simplified, the hardness and softness of the front and rear shock absorbers can be uniformly adjusted, and the reliability of their operation can be improved.

[Brief explanation of the drawing]

FIG. 1 is a pressure-voltage characteristic diagram of a semiconductor pressure sensor, FIG. 2 is a side view schematically showing the present invention,
FIG. 3 is a piping diagram of an embodiment of the present invention, FIG. 4 is a block diagram of a control device of an embodiment of the present invention, and FIG.
FIG. 3 is a flowchart showing measurement processing and pressure adjustment processing in an embodiment of the present invention. 10...Front fork, 12...Buffer,
14, 16, 22, 30... tube, 18, 20, 3
2...Solenoid valve, 24...Check valve, 34...Semiconductor pressure sensor, 40...Control device, 46...
ROM, 48...CPU, 50...RAM.

Claims (1)

[Scope of Claims] 1. A solenoid valve for opening and closing a passage provided in a passage communicating between an air spring of a damper interposed between a vehicle body and a wheel and a mounting chamber for a semiconductor pressure sensor, and a passage opening/closing solenoid valve that communicates between the pressure sensor mounting chamber and the atmosphere. an atmosphere side opening/closing solenoid valve provided in a passage communicating with the atmosphere side, and a control device for controlling the operation of the passage opening/closing solenoid valve and the atmosphere side opening/closing solenoid valve, and the control device includes a semiconductor pressure sensor. A ROM that stores a program to calculate the difference between the damper's air pressure measuring device and the measured value on the atmospheric side, a pressure measurement signal from a semiconductor pressure sensor, and a CPU.
A RAM is provided to temporarily store the calculation results, and the difference between the measured value of the damper air pressure and the measured value of atmospheric pressure is determined by the pressure measurement signal from the semiconductor pressure sensor stored in the RAM and the program stored in the ROM. In a shock absorber for a motorcycle, the solenoid valve for opening and closing the passage, which is connected to the air pump via a check valve, is connected to the air spring of the front fork of the front wheel and the shock absorber of the rear wheel. are connected in parallel to each of the air springs, and furthermore, a check valve, the one semiconductor pressure sensor, and the one atmospheric side opening/closing solenoid valve are connected from the air pump to one pipe between the two passage solenoid opening/closing valves. connected in series, and controlling the solenoid valve, etc. by the control device,
A shock absorbing device for a motorcycle, characterized in that an operation panel having a mechanism for switching between hard and soft air springs for a front wheel side and a rear wheel side air spring is connected to the control device.