JP2004352091A - Vehicle height adjusting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent unnecessary consumption of air, and to prevent average vehicle height after vehicle height adjustment from depending on a size relation of the right and left height, when adjusting the height. <P>SOLUTION: When a difference between the height in a left rear wheel side and the height of a right rear wheel side are not less than a specified value, a control unit 30 determines the size relation between the height in the left rear wheel side and the height in right and left wheel sides. The control unit 30 discharges air from an air spring in a side of the wheel having higher height according to a determined result, thereby controlling magnetic valves 8, 20 to make the height difference less than the specified value. Therefore, the height difference is not adjusted by supplying air to an air spring in a side of the wheel having lower height, so that the consumption of the air can be minimized when adjusting the height. The height difference is always adjusted by discharging air from the air spring in the side of the wheel having the higher height, so that the average height after adjusting the height is prevented from changing according to the size relation of the right and left height. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle height adjusting device for adjusting the height of a vehicle.
[0002]
[Prior art]
In a vehicle such as a large truck, a predetermined suspension stroke can be ensured, the riding comfort is improved, and the vibration of the carrier is effectively reduced. It is desired that the vehicle height) be maintained at a predetermined height (reference vehicle height) from the axle. Therefore, these vehicles are provided with an air suspension using an air spring as a chassis spring, and the height of the vehicle is adjusted by controlling the supply and exhaust of air to and from the air spring.
[0003]
However, if strict control is performed to maintain the vehicle height at the reference vehicle height, the vehicle height adjustment will be performed even when the vehicle height slightly changes from the reference vehicle height. Not only is not necessary, but on the contrary, there is a problem that air consumption increases. Therefore, when the vehicle height is within a predetermined distance (dead zone) above and below the reference vehicle height, the vehicle height adjustment is not performed, and frequent vehicle height adjustments are prevented.
[0004]
In this case, the vehicle heights of the adjacent wheel parts are one at the upper limit of the dead zone (position of distance x above the reference vehicle height) and the other is at the lower limit (position of distance x below the reference vehicle height). In some cases, the vehicle height difference (2x) between adjacent wheel portions becomes large, so that the inclination of the vehicle body posture becomes large, causing load collapse and deteriorating the appearance of the vehicle.
[0005]
Further, when the adjacent wheels are left and right, the vehicle is tilted left and right, and when the vehicle is stopped, the bed is tilted left and right with respect to the platform, and the cargo handling of the platform and the bed is deteriorated. In addition, during traveling, the suspension stroke may not be uniform between left and right, which may adversely affect steering stability.
[0006]
However, if the dead zone width is reduced to prevent this, frequent vehicle height adjustments will be prevented, and the original meaning of setting the dead zone will be lost. It is necessary to avoid a height difference.
[0007]
Therefore, in a vehicle provided with the air suspension, when the vehicle height difference between adjacent left and right wheel portions is larger than a predetermined value, as shown in Patent Document 1, for example, By adjusting the vehicle height of the wheel portion, the vehicle height adjustment is performed to reduce the inclination of the vehicle body posture and improve the appearance of the vehicle.
[0008]
[Patent Document 1]
Japanese Patent Publication No. Hei 7-37203
[Problems to be solved by the invention]
However, in the conventional vehicle height adjustment processing, (1) if the vehicle height at the left wheel portion is equal to or more than a predetermined upper value, air is discharged from the air spring on the left wheel portion side, and (2) the vehicle height at the left wheel portion is lower than the predetermined value. If it is less than the value, air is supplied to the air spring on the left wheel portion side. (3) If the vehicle height at the right wheel portion is above the upper predetermined value, air is discharged from the air spring on the right wheel portion side. (4) Right wheel If the vehicle height of the part is equal to or less than the lower predetermined value, priority is given to the air spring that performs the air supply / discharge processing, such as supplying air to the air spring on the right wheel part side, and the left and right wheel parts are distinguished. Control for reducing the height difference is performed.
[0010]
For this reason, according to the conventional vehicle height adjustment processing, for example, when the vehicle height of the right wheel region is equal to or more than the upper predetermined value, air is supplied to the air spring of the left wheel region side, for example, the vehicle height of the right wheel region is low. In some cases, the difference in vehicle height is adjusted by supplying air to the air spring, and in this case, the air is consumed.
[0011]
Furthermore, according to the conventional vehicle height adjustment processing, when the vehicle height of the left wheel portion is higher than the vehicle height of the right wheel portion, the vehicle height of the left wheel portion is reduced, and the vehicle height of the left wheel portion is the vehicle height of the right wheel portion. If the vehicle height is lower than that, the average vehicle height after adjusting the vehicle height changes depending on the magnitude relationship between the left and right vehicle heights, even if the difference in vehicle height between the left and right wheel parts is the same, in order to raise the vehicle height at the left wheel part I do.
[0012]
The present invention has been made in order to solve such a problem, and an object of the present invention is to minimize the air consumption and adjust the average vehicle height after the vehicle height adjustment to the relationship between the left and right vehicle heights. To provide a vehicle height adjustment device that does not depend on the vehicle height.
[0013]
[Means for Solving the Problems]
The feature of the vehicle height adjusting device according to the present invention is that in the vehicle height adjusting device that controls the supply and exhaust of air to and from the air spring, the vehicle height of the vehicle matches the reference vehicle height. Detecting vehicle height detecting means and calculating a vehicle height difference between the left and right wheel portions, and when the vehicle height difference is equal to or more than a predetermined value, determining a magnitude relationship between the vehicle heights and, based on the determination result, a wheel portion side having a higher vehicle height. And control means for controlling the vehicle height so that the vehicle height difference is less than a predetermined value by discharging air from the air spring.
[0014]
That is, according to the vehicle height adjusting device according to the present invention, when the vehicle height difference is equal to or more than the predetermined value, the control means reduces the vehicle height of the wheel portion having the higher vehicle height, thereby reducing the vehicle height difference. Control is performed so as to be less than a predetermined value. This eliminates the need to adjust the vehicle height difference by supplying air to the air spring on the wheel portion side where the vehicle height is low, so that it is possible to minimize air consumption during the vehicle height adjustment process. In addition, since the vehicle height is adjusted by adjusting the vehicle height difference by exhausting air from the air spring on the wheel portion side where the vehicle height is always higher, the average vehicle height after the vehicle height adjustment changes according to the magnitude relationship between the left and right vehicle heights. Can be prevented.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the configuration and operation of a vehicle height adjusting device according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0016]
FIG. 1 is a schematic diagram showing an air system on a rear axle side in a vehicle as one embodiment including a vehicle height adjusting device according to the present invention. Note that FIG. 1 shows only the rear axle side where the axial load changes greatly by loading a load on the carrier, and omits the front axle side where the axial load change is relatively small.
[0017]
As shown in FIG. 1, the vehicle according to this embodiment includes a rear front shaft and a rear rear shaft (not shown) on the rear shaft side. The rear front shaft is supported by side members (not shown) via four air springs 15 to 18, and the rear rear shaft is supported by side members (not shown) via four air springs 25 to 28. The air springs 15, 16 on the rear front axle side 40 are air springs for the right rear front wheel, the air springs 17, 18 are for the left rear front wheel, and the air springs 25, 26 on the rear rear axle side 41 are the rear right rear. The air springs 27 and 28 for the wheels are air springs for the rear left rear wheel.
[0018]
The air supply side of the air system includes a compressor (not shown), a main air tank 1 for storing air from the compressor, a first air tank 4 for the air springs 15 to 18 on the rear front shaft side 40, and a rear rear shaft side 41. And a second air tank 6 for the air springs 25 to 28. The first air tank 4 on the rear front shaft side 40 is connected in communication with the main air tank 1 via the air pipe 3, and the second air tank 6 on the rear rear shaft side 41 is connected to the air pipe 3 and the first air tank 4. In addition, it is connected to the main air tank 1 via the air pipe 5 in a communicating state. The first air tank 4 on the rear front shaft side 40 and the second air tank 6 on the rear rear shaft side 41 store air supplied to an air consuming side described later in a high pressure state.
[0019]
The air pipe 3 is provided with a safety valve 2 for preventing the internal pressure of the main air tank 1 from dropping below a predetermined value. That is, the safety valve 2 stops the supply of air from the main air tank 1 to the first and second air tanks 4 and 6 when the internal pressure of the main air tank 1 falls below a predetermined value for some reason, such as during running of the vehicle. As a result, the air pressure supplied from the main air tank 1 to a low-pressure air system including a brake system (not shown) is maintained, and vehicle safety is ensured.
[0020]
The air consuming side of the air system includes the magnetic valve 8 and the air springs 15 to 18 on the rear front shaft side 40, and the magnetic valve 20 and the air springs 25 to 28 on the rear rear shaft side 41. The magnetic valve 8 on the rear front shaft side 40 is connected in communication with the first air tank 4 via the air line 7, and the magnetic valve 20 on the rear rear shaft side 41 is connected to the first air tank 4 via the air line 19. 2 is connected to the air tank 6 in a communicating state.
[0021]
Further, the magnetic valve 8 on the rear front shaft side 40 is connected to the air springs 15 and 16 via the air pipe 9 in communication with the air springs 17 and 18 via the air pipe 10. Connected. The magnetic valve 20 on the rear rear shaft side 41 is connected in communication with the air springs 25 and 26 via the air pipe 21 and is connected in communication with the air springs 27 and 28 via the air pipe 22. Have been. The magnetic valve 8 on the rear front shaft side 40 is connected via a signal line 37 to a control unit 30 having a function as control means according to the present invention, and the opening / closing control sent from the control unit 30 is performed. The signal controls the supply / exhaust operation of supplying air from the first air tank 4 to the air springs 15 to 18 or exhausting the air from the air springs 15 to 18.
[0022]
Further, the magnetic valve 20 on the rear rear shaft side 41 is connected to the control unit 30 via a signal line 38, and the control signal sent from the control unit 30 causes the air from the second air tank 6 to be supplied to the air spring. An air supply / exhaust operation of supplying air to the air springs 25 to 28 or exhausting air from the air springs 25 to 28 is controlled.
[0023]
A pressure sensor 11 for detecting the internal pressure of the air line 9, that is, the internal pressure of the air springs 15, 16 is provided in the air line 9 on the rear front shaft side 40. , 18 are provided with a pressure sensor 12 for detecting the internal pressure. Further, a pressure sensor 23 for detecting the internal pressure of the air springs 25 and 26 is provided in the air line 21 on the rear rear shaft side 41, and the internal pressure of the air springs 27 and 28 is similarly set in the air line 22. A pressure sensor 24 for detection is provided. The pressure sensor 11 is connected to the control unit 30 via a signal line 33. Similarly, the pressure sensor 12 is connected via a signal line 34, the pressure sensor 23 is connected via a signal line 35, and the pressure sensor 24 is connected via a signal line 36. Are connected to the control unit 30. Then, the internal pressure values detected by the pressure sensors 11, 12, 23, 24 are sent to the control unit 30 via the corresponding signal lines 33, 34, 35, 36, respectively.
[0024]
The vehicle height adjusting device according to one embodiment of the present invention is provided with height sensors 13 and 14 having a function as a vehicle height detecting means according to the present invention. The height position, that is, the vehicle height on the rear axle side is detected. The height sensor 13 detects a vehicle height on the right rear wheel side, and the height sensor 14 detects a vehicle height on the left rear wheel side. The height sensor 13 is connected to the control unit 30 via a signal line 31, and the height sensor 14 is connected to the control unit 30 via a signal line 32. The vehicle height values detected by the height sensors 13 and 14 are sent to the control unit 30 via the corresponding signal lines 31 and 32, respectively. The control unit 30 sends air from the first and second air tanks 4 and 6 to the air springs 15 to 18 and 25 to 28 so that the current vehicle height values from the height sensors 13 and 14 match the reference vehicle height. The magnetic valves 8 and 20 are controlled so as to supply air or discharge air from the air springs 15 to 18 and 25 to 28 to the atmosphere.
[0025]
Further, in the vehicle height adjusting device according to one embodiment of the present invention, the control unit 30 first refers to the detection values of the height sensors 13 and 14 to refer to the left rear wheel side as shown in the flowchart of FIG. It is determined whether or not the absolute value of the difference between the vehicle height (YL) and the vehicle height (YR) on the right rear wheel side is equal to or greater than a predetermined value (X) (step S1). If there is, the magnitude relationship between the vehicle height on the left rear wheel side and the vehicle height on the right rear wheel side is determined (step S2). When the vehicle height on the left rear wheel side is higher than the vehicle height on the right rear wheel side as a result of the determination process, the control unit 30 controls the magnetic valves 8, 20 so that the vehicle height difference becomes smaller than a predetermined value. To lower the vehicle height on the left rear wheel side by discharging air from the air springs 17, 18, 27, 28 (step S3). On the other hand, when the vehicle height on the left rear wheel side is lower than the vehicle height on the right rear wheel side, the control unit 30 controls the magnetic valves 8, 20 so that the vehicle height difference becomes smaller than a predetermined value. By discharging air from the air springs 15, 16, 25, 26, the vehicle height on the right rear wheel side is reduced (step S4).
[0026]
As is apparent from the above description, according to the vehicle height adjusting apparatus according to the embodiment of the present invention, when the difference between the vehicle height on the left rear wheel side and the vehicle height on the right rear wheel side is equal to or more than a predetermined value, The control unit 30 determines the magnitude relationship between the vehicle height on the left rear wheel side and the vehicle height on the right rear wheel side.
Then, the control unit 30 controls the magnetic valves 8 and 20 so that the vehicle height difference becomes smaller than a predetermined value by discharging air from the air spring on the wheel having the higher vehicle height according to the determination result. . According to such a configuration, it is not necessary to supply the air to the air spring on the wheel side having a low vehicle height and to reduce the vehicle height difference, so that the consumption of air can be minimized. In addition, since the vehicle height is constantly adjusted by discharging air from the air spring on the wheel side with the higher vehicle height, the average vehicle height after vehicle height adjustment changes according to the magnitude relationship between the left and right vehicle heights. There is no.
[0027]
As described above, the embodiment to which the invention made by the present inventor is applied has been described. However, the present invention is not limited by the description and the drawings constituting a part of the disclosure of the present invention by this embodiment. For example, in the above embodiment, the vehicle height adjustment of the adjacent left and right wheel portions is performed, but the vehicle height adjustment of the adjacent front and rear wheel portions may be performed by similar processing. That is, it should be added that all other embodiments, examples, operation techniques, and the like performed by those skilled in the art based on this embodiment are included in the scope of the present invention.
[0028]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the vehicle height adjustment apparatus which concerns on this invention, the consumption of air at the time of a vehicle height adjustment process can be suppressed to the minimum.
[0029]
Further, according to the vehicle height adjusting device of the present invention, the average vehicle height after the vehicle height adjustment does not depend on the magnitude relationship between the left and right vehicle heights.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing an air system of a vehicle including a vehicle height adjusting device according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating an operation of the vehicle height adjusting device according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main air tank, 2 ... Safety valve, 3, 5, 7, 9, 10, 19, 21, 22 ... Air pipeline, 4 ... 1st air tank, 6 ... 2nd air tank, 8, 20 ... Magnetic valve, 11, 12, 23, 24: Pressure sensor, 13, 14, Height sensor, 15 to 18, 25 to 28: Air spring, 30: Control unit, 31 to 38: Signal line

Claims (1)

By controlling the supply and exhaust of air to and from the air spring, a vehicle height adjustment device that matches the vehicle height to a reference vehicle height,
Vehicle height detecting means for detecting the vehicle height of adjacent wheel parts;
The vehicle height difference between adjacent wheel parts is calculated, and if the vehicle height difference is equal to or greater than a predetermined value, the magnitude relationship between the vehicle heights is determined, and the air is discharged from the air spring on the wheel part with the higher vehicle height according to the determination result. Control means for controlling the vehicle height so that the vehicle height difference is less than a predetermined value.

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