JPH085301B2 - Truck bed height adjuster - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a height adjusting device for a bed of a truck, and in particular, supplies air to an air spring that constitutes at least a part of a suspension spring that suspends a rear shaft. Alternatively, the present invention relates to a height adjusting device for a bed of a truck, in which air is discharged from the air spring to adjust the height of the bed.

[Prior Art] At least a part of a suspension spring of a truck is composed of an air spring to supply air to the air spring or discharge air from the air spring to adjust the height of a cargo bed. Will be possible. 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 cargo bed to an arbitrary height with a push button, there is no step between the platform and the cargo bed. It is possible to easily load and unload luggage.

[Problems to be Solved by the Invention] In height adjustment by such a manual operation, if the loading platform is raised or lowered below the limit value, the shock absorber may be extended or the air spring may be damaged. It can be crushed and damaged. Therefore, in the case of height adjustment by such a manual operation, it is necessary to automatically stop the height adjustment operation at the limit value. This makes it possible to protect the suspension device. However, the driver in the cab cannot visually check the stopping operation, and cannot recognize that the adjusting operation is automatically stopped at the limit value.

The present invention has been made in view of such problems, and when performing vehicle height adjustment by manual operation,
It is an object of the present invention to provide a vehicle height adjusting device that ensures that the driver in a cab recognizes that the vehicle height adjusting operation is automatically stopped when the vehicle height exceeds a limit value. It is intended.

[Means for Solving the Problems] As shown in FIG. 1, the present invention supplies air to an air spring forming at least a part of a suspension spring for suspending a rear shaft, or supplies air from the air spring. In a truck bed height adjusting device for discharging and adjusting the bed height, a control panel provided at the rear end side of the gate of the bed, equipped with a manual operation means, a rear axle and a vehicle body A vehicle height sensor for detecting the height of the loading platform from the distance between them, a means for comparing the height of the loading platform detected by the vehicle height sensor with the upper and lower limit values, and the height of the loading platform for the upper and lower limit values. A means for holding the height of the bed at that position when the manual operation means is returned to the original position in a state where it does not exceed, and a means for stopping the height adjustment operation when the height of the bed exceeds the upper and lower limit values, Height adjustment of the loading platform An alarm means for issuing an alarm at the time of leveling is provided, and the height of the bed is adjusted by operating the manual operation means so as to adjust the height of the bed to an arbitrary height within the upper and lower limits. The present invention relates to a height adjusting device for a bed of a truck, characterized in that the height adjusting operation is stopped when the upper and lower limit values are exceeded and the alarm operation is stopped.

[Operation] Therefore, by operating the manual operation means of the control panel on the rear end side of the gate of the luggage carrier, the height of the luggage carrier can be adjusted by supplying / discharging air to / from the air spring. If the height of the bed is adjusted so that the upper and lower limit values are not exceeded and the manual operating means is returned to its original position, the height of the bed will be maintained at that position. Further, when the height adjustment operation of the truck bed exceeds the upper and lower limit values, the vehicle height adjustment operation is stopped when the upper and lower limit values are exceeded. Moreover, an alarm is issued by the alarm means during the height adjustment operation of the platform, and if it is stopped manually or the height adjustment operation is automatically stopped by exceeding the upper and lower limit values, an alarm is issued at that time. The operation is also stopped.

[Example] The present invention will be described below with reference to an illustrated example. 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 shaft 11 is suspended from a frame 13 via a leaf spring 12. A shock absorber is provided between the front shaft 11 and the frame 13.
14 are installed. On the other hand, the rear front shaft 15 is suspended by the leaf spring 16 on the frame 13, and the rear end portion of the leaf spring 16 is bent downward, and the rear end portion is supported by the air spring 17. ing. Then, a shock absorber 18 is also mounted between the front shaft 15 and the frame 13 after this. 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 respectively provided corresponding to the rear front shaft 15 and the rear rear shaft 19 are communicated with each other by a communication pipe 23, and a pair of these air springs are provided.
17 and 21 are age tanks 25 via magnetic valves 24
Connected with. The left and right air springs 17 and 21 are independent of each other, and they are separate surge tanks.
Equipped with 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.

In addition, this truck is equipped with a compressor 29.
The compressor 29 is connected to the wet tank 30, and the wet tank 30 is connected to the reservoir tank 32 via the protection valve 31. The reservoir tank 32 is connected to another reservoir tank 33, and is also connected to the automatic air supply valve 27 via a 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. Above automatic air supply valve 2
7. The automatic exhaust valve 28, the actuators 37 and 38 provided in the shock absorbers 18 and 22, and the cabsus shock absorber 39 are controlled by a microcomputer 40 that constitutes an electronic control device.

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. And 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. The panel 41 also has an operating lamp.
44 is provided and blinks according to an output signal from the microcomputer 40. Furthermore, on the instrument panel of the cab of this truck, a cab suspension switch 48 and an air suspension switch
49 is provided, and these switches 48 and 49 are also connected to the input side of the microcomputer 40.

Further, the transmission 50 of the 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, 52 are also input to the microcomputer 40. Further front axis
A bottoming detection sensor 53 that detects bottoming from the distance between the two is provided between the frame 11 and the frame 13, and is also connected to the input side of the microcomputer 40. 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 that form the rear suspension device are provided with load detection sensors 54 and 55 that detect 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, between the rear rear axle 19 and the frame 13, a vehicle height detection sensor for detecting the vehicle height from the distance between them.
56 is provided and is also 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 mounted on 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 reads the detection output of the vehicle height detection sensor 56, and at the same time, reads the microcomputer beforehand.
The standard value set at 40 is read and the actual vehicle height is compared with the standard value. When the actual vehicle height is higher than the standard value, the microcomputer 40 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 loading platform.

On the other hand, when 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 passed through the air supply valves 27 and the air springs 17 and 21. To raise the platform. Further, when the actual vehicle height and the standard value match, both the air supply valve 27 and the exhaust valve 28 are 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 equalized according to the loading amount on the loading platform. The load on the platform is detected stepwise by load detection sensors 54 and 55 composed of pressure sensors, and the detection output of these sensors 54 and 55 is read by the microcomputer 40. The magnetic valve 24 is opened and closed according to the load capacity.

When the load capacity is small, the magnetic valve 23 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, 38 increase the throttle diameters of the shock absorbers 18, 22 by the control signal from the microcomputer 40 to reduce the damping force. On the other hand, when a large load is detected by the sensors 54 and 55, the magnetic valve 24 is closed and the air spring 1
The spring constants of 7 and 21 are increased and the actuator 3
Strongly squeeze the shock absorbers 18, 22 with 7, 38,
The damping force is increased, and the suspension device is maintained in an optimum state according to the load capacity.

Next, the operation of height adjustment by manual operation of the platform will be described with reference to FIG. When manually adjusting the height of the truck bed to an arbitrary height, the mode selection button 43 of the control panel 41 shown in FIG. 2 is set to the "adjustment" mode, and the manual operation button 42 is "lifted". ] Or "Lower"
By switching to. When the operation button 42 is manually switched to "up", the compressed air in the reservoir tanks 32 and 33 is supplied to the air springs 17 and 21 through the air supply valve 27,
The vehicle height gradually rises. When the manual operation button 42 is switched to "down", the exhaust valve 28 is opened, and the compressed air in the air springs 17 and 21 is exhausted to the atmosphere through the exhaust valve 28. Will be lowered.

The operation of adjusting the height of the bed by such a manual operation is stopped by releasing the manual operation button 42 from the "up" or "down" position and returning it to the "holding" position. If such a switching operation is not performed, the platform is further raised upward or lowered further downward.
Then, the microcomputer 40 reads the height of the cargo bed at this time by the vehicle height detection sensor 56, and compares this value with the limit value set in the memory in the microcomputer 40. The vehicle height detection sensor 56 is adapted to generate a voltage according to the vehicle height, and this voltage will be compared with a reference voltage of an upper limit or a lower limit, thereby determining whether or not the limit value is exceeded. . When the limit value is exceeded, the air supply valve 27 or the exhaust valve 28 is closed so that the operation of manually adjusting the height of the bed is automatically stopped. Therefore, by such an operation, it is possible to prevent the shock absorbers 18 and 22 from fully extending or the air springs 17 and 21 from becoming flat.

In order to increase the safety during the manual operation of adjusting the height of the loading platform as described above, the microcomputer 40 operates the warning buzzer 58 at this time, and the warning buzzer 58 issues an alarm. I have to. Therefore, the driver inside the cab 47 must use this buzzer 58
This makes it possible to reliably recognize that the height adjustment operation of the platform is being performed. Moreover, the manual operation button 42
The microcomputer 40 stops the warning operation by the warning buzzer 58 when the vehicle height adjustment operation is stopped due to the cancellation of or the automatic stop is performed when the limit value is exceeded. Therefore, by stopping the alarm operation of the buzzer 58, it is possible to know the stop of the vertical movement of the bed. This makes it possible to more safely adjust the vehicle height or the height of the loading platform.

EFFECTS OF THE INVENTION As described above, according to the present invention, the height of the loading platform is adjusted to an arbitrary height within the upper and lower limits by the operation of the manual operating means. When is above the upper and lower limit values, the height adjustment operation is stopped and the alarm operation is stopped.

Therefore, within the range of the upper and lower limit values, the height of the carrier is adjusted by supplying air into the air spring or discharging air from the air spring by operating the manual operation means of the control panel. Moreover, if the manual operating means is returned to its original position while the height of the loading platform does not exceed the upper and lower limit values, the vehicle height will be maintained at that position, which will keep the truck within the upper and lower limit values. It will be possible to set the height of the cargo bed to any height.

The operation of adjusting the height of the loading platform of such a truck is provided on the rear end side of the loading platform gate, and is performed by a control panel having a manual operation means. Therefore, the height of the bed can be adjusted by constructing the manual operation means of the control panel on the rear end side of the gate of the bed. Therefore, the height of the loading platform can be correctly matched with, for example, the platform, and the operability for adjusting the vehicle height is excellent.

If the height of the bed exceeds the upper and lower limit values during such a height adjustment operation of the bed, the height adjustment operation will be automatically stopped, and the air spring will be fully extended and This prevents the cargo bed from becoming abnormally high.

When the height of the bed is adjusted by the manual operation means, the alarm means gives an alarm. Therefore, the vehicle height adjusting operation can be surely notified to the driver in the cab, and the vehicle height adjusting device with high safety can be provided. Moreover, when the height adjusting operation is stopped or when the height adjusting operation is automatically stopped by exceeding the upper and lower limit values, the alarm operation is also stopped accordingly. Therefore, the alarm operation is prevented from being continuously performed unnecessarily.

[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 truck bed according to an embodiment of the present invention, and FIG. 3 is a flowchart showing an operation of automatic height adjustment. FIG. 4 is a flow chart showing the operation of manual height adjustment. In the reference numerals used in the drawings, 17, 21 ...... Air spring 27 ...... Automatic air supply valve 28 ...... Automatic exhaust valve 41 ...... Control panel 42 ...... Manual operation button 43 ...... Mode selection button 56 ...... Vehicle height Detection sensor 58: A warning buzzer.

Claims (1)

[Claims] 1. A truck bed for supplying air to an air spring forming at least a part of a suspension spring for suspending a rear shaft or discharging air from the air spring to adjust the height of the bed. In the height adjusting device of the vehicle, a control panel provided on the rear end side of the gate of the loading platform and provided with manual operation means, and a vehicle height sensor for detecting the height of the loading platform from the distance between the rear axle and the vehicle body. , Means for comparing the height of the bed detected by the vehicle height sensor with the upper and lower limit values, and a means for returning the manual operation means to the original position while the height of the bed does not exceed the upper and lower limit values. Means for holding the height of the cargo bed at that position, means for stopping the height adjustment operation when the height of the cargo bed exceeds the upper and lower limit values, and alarm means for issuing an alarm when the height of the cargo bed is adjusted, Manual operation The height of the bed is adjusted to an arbitrary height within the upper and lower limits by operating the operating means, and the height adjustment operation stops the height adjustment operation when the height of the bed exceeds the upper and lower limit values. In addition, the height adjustment device for the truck bed is characterized in that the alarm operation is stopped.