JPS61268510A - Device for adjusting height of car - Google Patents

Abstract

PURPOSE:To prevent the height of a vehicle from being misadjusted to an unusual height by providing a manual operating means and a means of stopping an adjusting function for said manual operating means at above a set limit value. CONSTITUTION:An up-button 42 and a down-button 43 for manual operation is provided on a control panel 41, to carry out the lifting up and down of a rear body by operating these buttons 42, 43. At this time, a microcomputer 40 reads the output of a vehicle-height sensor 56 in accordance with the operation of the buttons and monitors the height of a vehicle for its being lifted up and down above a limit value. When the height is within the limit value, it allows the height of vehicle to be adjusted, while lighting a lamp 46 to indicate that an operation is under way. When the height exceeded the limit value, the lamp 46 is turned off, and an intake valve 27 or an exhaust valve 28 is closed to stop the operation. Due to this construction, misadjustment to an unusual height can be prevented.

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a height adjustment device for a vehicle, and in particular, at least a portion of a suspension spring is composed of an air spring, and the supply and discharge of air to the air spring is controlled by an electronic control device. The present invention relates to a vehicle height adjustment device for adjusting the height of a vehicle body.

[Summary of the invention]

The present invention provides a manual operation means such as a push button, and by operating this manual operation means, the height can be adjusted to a desired value. The height adjustment operation by the manual operation means is stopped when the lower limit value is exceeded, thereby preventing the vehicle height from being adjusted to an abnormal height. 2. Description of the Related Art By constructing at least a portion of a suspension spring from an air spring, the height of the vehicle or the height of the cargo platform is increased by supplying air to the air spring. Also, by discharging air from this air spring, the height of the loading platform is lowered. Therefore, with such a configuration, it becomes possible to adjust the vehicle height relatively easily. However, by supplying and discharging the air using magnetic valves, it becomes possible to adjust the height of the loading platform by electronic control. Furthermore, such a device is provided with operating means such as a manually operated push button, and the push button is pressed to open and close the magnetic valve, thereby controlling the supply of air to the air spring and the flow of air from the air spring. If the discharge can be performed manually, it becomes possible to change the height of the loading platform to a desired height. Therefore, when loading and unloading cargo onto the platform, it is possible to eliminate the difference in level between the loading platform and the platform.

[Problems to be solved by the invention]

However, when a manual operation means such as a manually operated push button is added to the electronic control device, the loading platform may be held at an abnormally high position due to manual operation by this manual operation means, or There is a possibility that it will be lowered to an abnormally low position. If the loading platform is raised too high, the shock absorber will be fully extended and the pressure inside the air spring will become abnormally high. Therefore, if the truck runs in such a state, there is a possibility that excessive force will be applied to the shock absorber or air spring, causing damage to the shock absorber or air spring. Furthermore, when the loading platform is lowered to an abnormally low position, most of the air in the air spring is exhausted, causing the frame and axle to come into contact. Furthermore, in a truck with two rear axles, the entire load is applied to the rear axle, creating the possibility that the tires on the rear axle may bank. Furthermore, since most of the air is exhausted, the amount of air consumed increases abnormally, and the time required for restoration becomes longer. The present invention has been made in view of these problems, and is intended to prevent the height from being changed to an abnormally high or low value by manual operation, thereby preventing suspension devices and wheels from being changed to abnormally high or low values. The object of the present invention is to provide a height adjustment device for a vehicle that protects the vehicle and also reduces air consumption.

[Means to solve the problem]

The present invention is applicable to a vehicle having a small number of suspension springs (some of which are composed of air springs, and in which the air supply and discharge to the air springs are controlled by an electronic control device to perform adjustment). An operating means is provided, and the height is adjusted to a desired value by the manual operating means, and the height adjustment by the manual operating means is stopped when the height exceeds a preset limit value. This is what I did.

[Effect] Therefore, according to the present invention, it is possible to adjust the height using the manual operating means, and to prevent the vehicle height from being changed to an abnormal height due to the operation using the manual operating means. K example]

The present invention will be explained below with reference to an illustrated embodiment. FIG. 1 is a block diagram showing a truck bed height adjustment device according to an embodiment of the present invention, in which a front axle 11
is suspended from a frame 13 via leaf springs 12. A shock absorber 14 is interposed between the front shaft 11 and the frame 13. On the other hand, the rear and front shafts 15 are suspended from the frame 13 by leaf springs 16, and the rear ends of the leaf springs 16 are bent downward, and are supported by air springs 17. ing. A shock absorber 18 is also installed between the leaf spring 16 and the frame 13. Similarly, the rear axis 19
is suspended on the frame 13 by a leaf spring 20 and an air spring 21, and a shock absorber 2 is provided between the leaf spring 20 and the frame 13.
2 is interposed. The air springs 17.21 provided corresponding to the rear-front shaft 15 and one rear-rear shaft are communicated with each other through a communication pipe 23, and these pair of air springs 17.21 are connected to a magnetic valve 24. It is connected to the surge tank 25 via. Note that the left and right air springs 17, 21 are independent from each other, and each uses a separate surge tank 25. The left and right air springs 17 and 21 are connected to an automatic air intake valve 27 and an automatic exhaust valve 28 via an air supply and exhaust vibe 26, respectively. Furthermore, this truck is equipped with a compressor 29. The compressor 29 is connected to a wet tank 30, and the wet tank 30 is connected to a protection valve 3.
It is connected to the reservoir tank 32 via 1. And the reservoir tank 32 is yet another reservoir tank 33
It is also connected to the automatic air supply valve 27 via the check valve 34. Furthermore, this check valve 34 is connected to a pair of air springs 17, 21 via a manually operated air supply valve 35. A manual exhaust valve 36 is connected to the manual air supply valve 35 . The above automatic air supply valve 27 and automatic exhaust valve 28
, actuators 37, 38 provided on the shock absorbers 18, 22, and the cab suspension shock absorber 39 are controlled by a microcomputer 40 constituting an electronic control device. A control panel 41 is connected to the input side of this microcomputer 40. This panel 41 is attached to the rear end of the gate on the right side of the loading platform. The panel 41 is provided with an up button 42, a down button 43, a restore button 44, and an emergency stop button 45, respectively. Further, this panel 41 is provided with a display lamp 46, which blinks in response to an output signal from the microcomputer 40. Additionally, there is a cab suspension selector switch 48 on the instrument of the cab of this truck.
, an air suspension changeover switch 49 are provided, and these switches 48 and 49 are also connected to the input side of the microcomputer 40. Further, the transmission 50 of this truck is provided with a gear position detection sensor 51 and a vehicle speed detection sensor 52, respectively, and the outputs of these sensors 51 and 52 are also input to the microcomputer 40. Furthermore, a bottoming detection sensor 5 is provided between the front axle 11 and the frame 13 to detect bottoming from the distance between the two.
3 is provided, and also a microcomputer 40
connected to the input side of the On the other hand, the air supply and exhaust pipes 26 of the air springs 17.21 constituting the rear suspension device are provided with live load detection sensors 54.55 that detect the live load from the pressure of these air springs 17.21. There is. These sensors 54 and 55 perform detection operations using different pressures, and are both connected to the input side of the microcomputer 40. Furthermore, a vehicle height detection sensor 56 is provided between the rear axle 19 and the frame 13 to detect the vehicle height from the distance between the two, and is similarly connected to the input side of the microcomputer 40. A warning lamp 5.7 and a warning buzzer 58 are connected to the output side of the microcomputer 40, respectively. These lamps 57 and buzzers 5
8 are both attached to the instrument panel of the cab 47. Next, the operation of the truck bed height adjusting device having the above configuration will be explained. The operation of setting the loading platform to the standard height is performed by the microcomputer 40 based on the flowchart shown in FIG. That is, the microcomputer 40 controls the vehicle height detection sensor 5.
In addition to reading the detection output of No. 6, a standard value preset in the microcomputer 40 is also read, and the actual vehicle height is compared with the standard value. If the actual vehicle height is higher than the standard value, the microcomputer 4
0 causes the automatic exhaust valve 28 to open. The air within the air spring 17.21 is then exhausted through the exhaust valve 28, thereby lowering the height of the cargo platform. On the other hand, if the actual vehicle height is lower than the standard value,
The automatic air supply valve 27 is opened and the compressed air stored in the reservoir tank 32.33 is supplied to the air spring 17.21 through the air supply valve 27 to raise the cargo platform. In addition, if the actual vehicle height and the standard value match, the air intake valve 27
, and exhaust valve 28 are both held closed. In this way, it is possible to always hold the loading platform in a predetermined position. Note that the standard value is stored in the microcomputer 40 as a value with a predetermined width. Furthermore, in this truck, the spring constant and damping force of the suspension device are changed depending on the amount of load on the platform. The load on the loading platform is detected in stages by load detection sensors 54 and 55 consisting of pressure sensors.
The microcomputer 40 reads the detection output of 55. Then, the magnetic valve 24 is opened and closed depending on the amount of money to be loaded. product! If ffl is low, magnetic valve 24
Open the surge tank 25 and air spring 17.21
to lower the spring constant of the suspension device. At the same time, the control signal from the microcomputer 40 causes the actuators 37, 38 to increase the aperture diameter of the shock absorber 18, 22 to reduce its damping force. On the other hand, if a large product [1 is detected by the sensor 54, 55, the magnetic valve 24 is closed to increase the spring constant of the air spring 17, 21, and the actuator 37, 38 acts on the shock absorber 18. 22 is strongly throttled to increase its damping force, and the suspension device is maintained in an optimal state according to the load amount. Furthermore, in the truck according to this embodiment, the height of the loading platform of the i-rack can be adjusted to any desired position by manual operation using a raise button 42 and a lower button 43 provided on the control panel 41. ing. For example, if the cargo bed is to be raised to match the platform, the lift button 42 may be pressed. As shown in FIG. 3, the microcomputer 40 has a control panel 4.
1 is read, and it is determined whether the switch linked to the up button 42 is ON. When this switch is ON, the output of the vehicle height detection sensor 56 is read and it is determined whether or not 1a is below the limit value. If it is below the upper limit in the height direction, manual operation is permitted, and the microcomputer 40 automatically controls the air supply valve 2.
7 will be held. Therefore, air spring 17.
Compressed air is supplied to each of the terminals 21 and the loading platform rises. At this time, the lamp 46 on the panel 41 is lit to notify that it is in operation. The operation of the upper limit of the loading platform by this raise button 42 is as follows.
It will stop if you let go of it or if the height of the platform exceeds the limit value. That is, as shown in FIG. 4, during the lifting operation of the loading platform, the microcomputer 40
reads the output of the control panel 41 at regular intervals and determines whether the switch linked to the up button 42 is on. When this switch is OFF, the air supply valve 27 is closed. When this switch is ON, the vehicle height detection sensor 5
6 is read, and it is determined whether this value is greater than or equal to the limit value, and if it is greater than or equal to the limit value, the air supply valve 27 is similarly closed. At the same time, the display lamp 46 on the panel 41 is turned off. This causes the lifting operation of the loading platform to be stopped. As described above, according to the vehicle height adjustment device for a loading platform according to the present embodiment, the height of the loading platform can be raised to an arbitrary height using the raise button 42 of the control panel 41, and the height of the loading platform can be raised to an arbitrary height. When the value is reached, even if the button 42 is pressed, the microcomputer 40 automatically closes the automatic air supply valve 27 and stops the rising operation. Therefore, the shock absorber 18.22 is prevented from being fully extended, the pressure within the air spring 17.21 is prevented from increasing abnormally, and the suspension device is prevented from being damaged by excessive force. Note that this limit value is 1
It is preferable to set the value to about 00 to 200 inches. Since the display lamp 46 of the control panel 41 is turned on during the lifting operation of the loading platform, the lamp 46 notifies the operator of the lifting operation, thereby increasing safety. Moreover, this lamp 46
Since the light is turned off when the lifting operation is stopped, it becomes possible to easily confirm the lifting operation of the loading platform. Furthermore, the platform is raised only when the lift button 42 is pressed, and since the panel 41 equipped with this button 42 is provided at the rear end of the gate on the right side of the platform, safety is ensured. It has become more sexual. Next, when lowering the loading platform to a desired position, the lowering button 43 can be used to perform the same operation as shown in FIG. That is, when the down button 43 is pressed and the corresponding switch is closed, if the lower limit value is below or below, the exhaust valve 28 is opened and air is exhausted from the air spring 17. A descending operation is started. At this time as well, the display lamp 46 is lit. This lowering operation of the loading platform is performed by an operation similar to that shown in Fig. 4.
When the lowering button 43 is released and the platform is lowered beyond the lower limit, the automatic exhaust valve 28 closes and the exhaust of air from the air spring 17.21 is stopped. At the same time, the lamp 46 will be turned off. In this way, even when the loading platform is lowered, the frame 1 is prevented from being lowered beyond the limit value.
3 is prevented from contacting the rear rear shaft 19, and the rear rear shaft 19 is prevented from contacting the rear rear shaft 19.
This prevents a full load from being applied to the rear axle 19 and from blowing out the tire on the rear axle 19 side. Also air spring 17.21
Since the air inside is not discharged more than necessary, it is possible to save on air consumption. In addition, the time required to restore the height to the standard height can be reduced. Furthermore, during this lowering operation, the operation is stopped when the button 43 is released, and during the lowering operation, this can be notified by the display lamp 46, thereby increasing safety.

【Effect of the invention】

As described above, the present invention provides a manual operating means, and uses the manual operating means to adjust the height to a desired value, and when the height exceeds a preset limit value, the manual operating means adjusts the height to a desired value. The height adjustment is stopped. Therefore, according to the present invention, the vehicle body is prevented from changing to an abnormally high or low position due to the operation by the manual operation means.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a truck bed height adjustment device according to an embodiment of the present invention, FIG. 2 is a flowchart showing the normal control operation of this height adjustment device, and FIG. 3 is a manual control operation. FIG. 4 is a flowchart showing the lifting operation of the loading platform. FIG. 4 is a flowchart for stopping the lifting operation of the loading platform. In addition, in the symbols used in the drawings, 17.2 Air spring 27...Automatic air supply valve 28...Automatic exhaust valve 40...Microcomputer 41...Control panel 42...Up Button 43...Down button 56...Vehicle height detection sensor.

Claims (1)

[Claims] In a vehicle in which at least a part of the suspension spring is composed of an air spring, and the height is adjusted by controlling the supply and discharge of air to the air spring by an electronic control device, a manual operation means is provided, and the height is adjusted by controlling the supply and discharge of air to the air spring. The height is adjusted to a desired value by the manual operation means, and when the height exceeds a preset limit value, the height adjustment by the manual operation means is stopped. Vehicle height adjustment device.