JPH0649408B2 - Vehicle height adjustment device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle height adjusting device, and in particular, at least a part of a suspension spring is composed of an air spring, and air is supplied to the air spring in accordance with the operation of a manual operation means. The present invention relates to a vehicle height adjusting device that adjusts the vehicle height by supplying air or discharging air from an air spring.

[Outline of Invention]

The present invention is a device capable of adjusting the vehicle height by a manual operation means so that an alarm is issued when the vehicle is switched to a travelable state and an operation of automatically restoring the vehicle height is performed. Is.

[Conventional technology]

By forming at least a part of the suspension spring of the truck from an air spring, it is possible to supply air to the air spring or discharge air from the air spring to adjust the height of the carrier. Furthermore, by controlling the supply and discharge of this air by an electronic control device such as a microcomputer, and by setting the height of the loading platform to an arbitrary height by a push button,
It becomes possible to easily load and unload luggage by eliminating the step between the platform and the loading platform.

[Problems to be solved by the invention]

However, in a vehicle in which the height of the loading platform is adjusted by operating the manual operation means in this manner, the vehicle height may be changed to a significantly high state or a low state due to the manual operation. Therefore, when the vehicle travels in such a state, there is a possibility that the travel may be inconvenient.

The present invention has been made in view of such a problem, and in a vehicle in which the vehicle height is manually adjusted, it is possible to prevent the vehicle from traveling while the vehicle height is extremely high or low. It is an object of the present invention to provide a vehicle height adjusting device that can be prevented in advance.

[Means for solving problems]

The present invention provides an apparatus in which at least a part of a suspension spring is composed of an air spring, and a vehicle height is adjusted by supplying or discharging air to the air spring according to an operation of a manual operation means, Detection means for detecting the release of the parking brake, detection means for detecting the shift of the transmission to a travelable gear position, means for automatically restoring the vehicle height to a travelable vehicle height, release of the parking brake and transmission First alarm means for issuing a first alarm upon detection of one of switching to a gear position in which travel is possible, and detection of both releasing the parking brake and switching to a gear position in which the transmission can travel. And a second alarm means for issuing a second alarm accordingly. When the gear is released and the transmission is switched to a gear position in which the vehicle can travel, the first and second alarms are issued, and the vehicle height is automatically restored. It is about.

[Operation] Therefore, the first warning means issues the first warning upon detection of one of the release of the parking brake and the switching to the gear position in which the transmission can travel.
Also, with the detection of both the release of the parking brake and the switching to the gear position where the transmission can run,
A second alarm will be issued by the second alarm means. Further, when the parking brake is released and the transmission is switched to a gear position in which the vehicle can travel, the vehicle height is automatically restored to the vehicle height in which the vehicle can travel.

〔Example〕

The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 2 is a block diagram showing a height adjusting device for a truck bed according to an embodiment of the present invention, in which a front wheel 11 is suspended by a frame 13 via a leaf spring 12. A shock absorber 14 is interposed between the front shaft 11 and the frame 13. On the other hand, the rear front wheel 15 is suspended on the frame 13 by the leaf spring 16, and the rear end portion of the leaf spring 16 is bent downward.
I am trying to support it. And after this front wheel 1
A shock absorber 18 is also attached between the frame 5 and the frame 13. Similarly, the rear rear shaft 19 is suspended on the frame 13 by a leaf spring 20 and an air spring 21, and a shock absorber 22 is interposed between the rear rear shaft 19 and the frame 13.

The air springs 17 and 21 provided respectively corresponding to the rear front shaft 15 and the rear rear shaft 19 are connected to each other by a communication pipe 23, and the pair of air springs 17 and 21 are connected via a magnetic valve 24. Connected to the surge tank 25. The left and right air springs 17 and 21 are independent of each other, and each has a separate surge tank 25. The left and right air springs 17 and 21 are connected to an automatic air supply valve 27 and an automatic exhaust valve 28 via a supply / exhaust pipe 26, respectively.

Furthermore, the truck is equipped with a compressor 29.
The compressor 29 is connected to the wet tank 30, and the wet tank 30 includes the protection valve 3
1 to the reservoir tank 32. Then, the reservoir tank 32 is a different reservoir tank 33.
It is also connected to the automatic air supply valve 27 via the check valve 34. Further, the check valve 34 is connected to a pair of air springs 17 and 21 via a manual air supply valve 35.
A manual exhaust valve 36 is connected to the manual air supply valve 35. The automatic air supply valve 27, the automatic exhaust valve 28,
The actuators 37 and 38 and the cabsus shock absorber 39 provided on the shock absorbers 18 and 22, respectively, are controlled by a microcomputer 40 that constitutes an electronic control unit.

A control panel 41 is connected to the input side of the microcomputer 40. This panel 41 is attached to the rear end of the gate on the right side of the luggage carrier. The panel 41 is provided with a manual operation button 42 for manually adjusting the vehicle height and a mode selection button 43 for selecting a vehicle height adjustment mode. Further, the panel 41 is provided with an operation lamp 44, and blinks by an output signal from the microcomputer 40. Further, a cab suspension switch 48 and an air suspension switch 49 are provided on the instrument panel of the cab of this truck, and these switches 48 and 49 are also connected to the input side of the microcomputer 40.

A gear position detection sensor 51 and a vehicle speed detection sensor 52 are provided in the transmission 50 of the truck, and the outputs of these sensors 51 and 52 are also input to the microcomputer 40.
Further, between the front shaft 11 and the frame 13, a bottoming detection sensor 5 for detecting bottoming from a distance between the front shaft 11 and the frame 13.
3 is also provided, and the microcomputer 40 is also provided.
Is connected to the input side of. A parking brake sensor 61 is provided on the parking brake lever 60, and its output is input to the microcomputer 40.

On the other hand, the supply / exhaust pipes 26 of the air springs 17 and 21 constituting the rear suspension device are provided with load detection sensors 54 and 55 for detecting the load from the pressure of these air springs 17 and 21. There is. These sensors 54 and 55 are designed to perform detection operations at different pressures, and are both connected to the input side of the microcomputer 40. Further, a vehicle height detection sensor 56 for detecting the vehicle height from the distance between the rear and rear axles 19 and the frame 13 is provided, and similarly connected to the input side of the microcomputer 40. A warning lamp 57, a warning buzzer 58, and an alarm buzzer 59 are connected to the output side of the microcomputer 40. Both the lamp 57 and the buzzers 58 and 59 are attached to the instrument panel of the cab 47.

Next, the operation of the height adjusting device for the bed of the truck according to the above configuration will be described. The operation of setting the platform to the standard height is performed by the microcomputer 40 based on the flowchart shown in FIG. That is, the microcomputer 40 uses the vehicle height detection sensor 5
In addition to reading the detection output of 6, the standard value preset in the microcomputer 40 is 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 opens the automatic exhaust valve 28. Then, the air in the air springs 17 and 21 is discharged through the exhaust valve 28, thereby lowering the height of the cargo bed.

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 tanks 32 and 33 is supplied to the air springs 17 and 21 through the air supply valve 27 to raise the loading platform. If the actual vehicle height matches the standard value, the air supply valve 2
7 and the exhaust valve 28 are both kept closed. In this way it is possible to keep the platform always in place. The standard value is stored in the microcomputer 40 as a value having a predetermined width.

Further, in this truck, the spring constant and the damping force of the suspension device are changed according to the loading amount on the loading platform. The load on the platform is detected stepwise by load detection sensors 54 and 55 which are pressure sensors.
The microcomputer 40 reads the detection output of 55.
The magnetic valve 24 is opened and closed according to the loading amount.

When the loading amount is small, the magnetic valve 24 is opened and the surge tank 25 and the air springs 17 and 21 are communicated with each other to reduce the spring constant of the suspension device.
At the same time, the actuators 37 and 38 increase the throttle diameter of the shock absorbers 18 and 22 and decrease the damping force thereof by the control signals from the microcomputer 40. On the other hand, when a large load is detected by the sensors 54 and 55, the magnetic valve 24 is closed to increase the spring constants of the air springs 17 and 21, and the actuators 37 and 38 cause the shock absorbers 18 and 22 to move. Is strongly squeezed to increase its damping force, and the suspension device is maintained in an optimum state according to the load capacity.

Next, the operation of adjusting the height of the bed of the truck will be described. This operation is performed by operating the buttons 42 and 43 of the control panel 41 as shown in the flowchart of FIG. That is, first, the mode selection button 43 is switched to "adjustment" and the manual operation button 42 is switched to "up" or "down". By this operation, the compressed air is supplied to the air springs 17 and 21 through the air supply valve 27, or the compressed air inside the air springs 17 and 21 is discharged through the exhaust valve 28, and the cargo bed can be set at an arbitrary position. Can be set to height. This vehicle height adjustment operation is stopped by releasing the manual operation button 42, and is stopped when the upper limit value or the lower limit value preset in the microcomputer 40 is reached. The valve 27 or the exhaust valve 28 comes to close. This allows the truck bed to be set at an optimum height for loading and unloading luggage.

If the vehicle travels as it is after the height adjustment of the loading platform is performed by such a manual operation, traveling may be hindered. Therefore, such a situation is avoided as shown in FIG. The microcomputer 40 determines whether the mode selection button 43 is "running", detects the shift position of the transmission 50 by the gear position sensor 51, and also determines the state of the parking brake 60 by the parking brake sensor 6.
I am trying to read by 1. Even if the mode selection button 43 is not in the "running" mode, if the transmission 50 is shifted and the parking brake is released, the alarm buzzer 59 is activated to give a large alarm sound. ing. When either one of the shift of the transmission 50 and the release of the parking brake is performed, the warning buzzer 58 emits a small alarm sound. Therefore, the mode selection button 43 of the control panel 41
If the vehicle is not returned to the traveling mode and the vehicle is switched to the traveling state while the vehicle height is being adjusted, for example, it becomes possible to effectively inform the driver of that fact. .

Further, in this vehicle height adjusting device, the microcomputer 40 reads the output of the vehicle height detection sensor 56 in a state where the vehicle can travel, that is, in a state where the transmission 50 is shifted and the parking brake is released, and From the value, it is determined whether the vehicle height is within the travelable range. If the vehicle height is out of the travelable range, the vehicle height is automatically restored. This automatic restoration operation is similar to the automatic adjustment operation of the vehicle described above, and can be achieved by opening the air supply valve 27 or the exhaust valve 28 by the microcomputer 40. I am trying to return it to a proper value. Therefore, it is possible to avoid various inconveniences caused by the vehicle traveling in a state where the vehicle height is extremely high or low, and it is possible to obtain a vehicle height adjusting device with high safety. The automatic restoration operation is stopped by returning the transmission 50 to the neutral position or pulling the parking brake lever 60, as shown in FIG.

In the alarm operation based on the program shown in FIG. 5, the alarm buzzer 5 is switched by switching the mode selection button 43 to the "running" position in accordance with the operation of the alarm buzzer.
9 or the warning buzzer 58 stops the alarm operation. However, in this case, since the mode selection button 43 is originally switched with the intention of intentionally restoring to the traveling mode, the automatic restoration operation is continued as it is, and the vehicle is traveling at the vehicle height or the height of the loading platform. I try to restore it to the highest possible height.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention includes a detection unit that detects the release of the parking brake, a detection unit that detects switching of the transmission to a gear position where the transmission can travel, and a unit that automatically restores the vehicle height to a travelable vehicle height. A first alarm that is issued upon detection of one of releasing the parking brake and switching to a gear position in which the transmission can travel
And a second alarm means for issuing a second alarm upon detection of both release of the parking brake and switching of the transmission to a gear position in which the transmission can run, and the parking brake is released. When the transmission is switched to a gear position in which the transmission can travel, the first and second alarms are issued, and the vehicle height is automatically restored.

Therefore, when the parking brake is released and the transmission is switched to a gear position in which the transmission can be driven while the vehicle height is kept extremely high or low by, for example, manual operation, the first alarm and the first alarm are issued. The alarm No. 2 is issued, and the driver can be surely notified of that. In addition, the vehicle height is automatically restored, and the vehicle height is automatically restored to a vehicle height at which the vehicle can travel. Therefore, the vehicle may be driven in an extremely high or low state. Will be avoided.

[Brief description of drawings]

FIG. 1 is a block diagram showing the gist of the present invention, FIG. 2 is a block diagram showing a height adjusting device for a bed according to an embodiment of the present invention, and FIG. 3 is a flowchart showing an operation for adjusting the height of the bed. FIG. 4 is a flow chart showing the operation of adjusting the height of the loading platform by manual operation, and FIG. 5 is a flow chart showing the operation of the alarm and automatic restoration accompanying switching to the running state of the vehicle. In the reference numerals used in the drawings, 17, 21 ... Air spring 27 ... Automatic air supply valve 28 ... Automatic exhaust valve 40 ... Microcomputer 41 ... Control panel 42 ... Manual operation button 43 ... Mode selection button 51 ... Gear position detection sensor 58 ... Warning buzzer 59 ... Warning buzzer 61 ... Parking brake sensor.

Claims (1)

[Claims] 1. An apparatus in which at least a part of a suspension spring is composed of an air spring, and a vehicle height is adjusted by supplying or discharging air to or from the air spring according to an operation of a manual operation means. , A detection means for detecting the release of the parking brake, a detection means for detecting the shift of the transmission to a travelable gear position, a means for automatically restoring the vehicle height to a travelable vehicle height, a release of the parking brake and a transmission First alarm means for issuing a first alarm upon detection of one of the shifts to the travelable gear position of the vehicle, and detection of both the release of the parking brake and the shift of the transmission to the travelable gear position. A second alarm means for issuing a second alarm in association with When the gear is released and the transmission is switched to a gear position in which the vehicle can travel, the first and second alarms are issued and the vehicle height is automatically restored. apparatus.