JPS61241210A - Height adjusting device for truck rear body - Google Patents

Abstract

PURPOSE:To keep the predetermined constant height of the rear end of a rear body from the ground independent of a rear body deflection, etc. by providing a body height sensor near the rear end of the said body and detecting directly rear body height from the ground through the said sensor. CONSTITUTION:An air spring 19 is provided between the rear end of a leaf spring suspending both a rear forward shaft 14 and a rear shaft 15, and a frame 12. This air spring 19 is connected to an air tank 23, via a suction and exhaust valve 22, and the electro-magnetic coil 24 of the said valve 22 is controlled by a micro computer working on an output detected at a body height sensor 26. In this case, the said sensor 26 is positioned near the rear end of the rear body on the frame 12 and the height of the rearbody from the ground is directly detected by the sensor 26, thereby ensuring the predetermined constant height of the rear end of the rear body from the ground independent of the deflection of the rear body or the frame 12, the deformation of a tire, and the like.

Description

[Detailed description of the invention]

Field of Application M The present invention relates to a vehicle height adjustment device for a truck bed, and in particular, a device for detecting the height of a truck bed from the ground using a sensor and adjusting the vehicle height in accordance with the detection by the sensor. This article relates to a vehicle height adjustment device. KSummary of the invention] The present invention directly detects the height of the truck bed from the ground using a sensor installed near the rear end of the truck bed, and operates a vehicle height adjustment device in response to this detection. hand]
・It is designed to adjust the height of the rack loading platform from the ground, so that the height of the loading platform, especially the rear end where the sensor is installed, remains constant regardless of the deflection of the loading platform due to the load of the cargo or the deflection of the tires. It was designed so that it could be maintained at a height of Furthermore, when the vehicle is backing up, the sensor is directed rearward and operates as a rear obstacle detection device, thereby increasing safety when backing up. K. PRIOR ART A conventional device for adjusting the vehicle height of a truck is shown in FIG. 8, for example. That is, a vehicle height sensor 2 is attached to the bottom surface of the truck bed 1, and
This sensor 2 is connected to the axle 5 via a rod 3 and an arm 4.
It was becoming connected to. The axle 5 is suspended by a leaf spring 6, and one end of the leaf spring 6 is supported by the frame via an air spring 7. Therefore, according to such a vehicle height adjustment device, the leaf spring 6 or the air spring 7 deforms depending on the load applied to the cargo platform, and the distance between the frame and the axle 5 changes accordingly. , this is detected by the vehicle height sensor 2. Then, by adjusting m of the air supplied to the air spring 7 in accordance with this detection, the height of the loading platform 1 is maintained at a substantially constant height. Alternatively, a rotary vehicle height detection sensor has been proposed in Japanese Utility Model Application Publication No. 57-159508. Even in such a sensor, the vehicle height is detected by a change in the distance between the frame and the axle, and therefore the same detection as the conventional vehicle height detection shown in FIG. 8 is performed.

[Problems to be solved by the invention]

In a conventional truck equipped with a vehicle height adjustment device as shown in FIG. A step e is likely to occur between the two. This is because the vehicle height sensor 2 measures the distance between the frame and the axle 5, so it cannot detect the deflection of the cargo platform 1 or the deflection of the tires 8 due to the load of the cargo 10.
This is also because the vehicle height adjustment device linked to the detection by the sensor 2 does not correct the level difference e. Therefore, with such a conventional truck, there is a possibility that loading and unloading of the cargo 10 may not be carried out smoothly. The present invention has been made in view of these problems, and provides a truck equipped with a vehicle height adjustment device so that the rear end of the truck bed, in particular, is always maintained at a constant height above the ground. The purpose is to

[Means to solve the problem]

The present invention provides an apparatus that includes a loading platform, detects the height of the loading platform from the ground by a sensor, and adjusts the vehicle height in accordance with the detection by the sensor, in which The above-mentioned sensor is provided, and the height of the loading platform from the ground is directly detected by the sensor. 1. Therefore, according to the present invention, the vehicle height is adjusted so that the rear end of the cargo platform is always maintained at the correct height above the ground, thereby facilitating the loading and unloading of cargo. You will be able to do things. Further, if the sensor is rotatably supported and the sensor is directed rearward by a driving means when the vehicle moves in or out, for example, it becomes possible to use the sensor also as a rear obstacle detection device.

【Example】

The present invention will be explained below with reference to an illustrated embodiment. FIG. 1 shows a truck equipped with a vehicle height adjustment device according to an embodiment of the present invention, and a loading platform 13 is placed on the frame 12. As shown in FIG. The rear end side of the frame 12 is supported by wheels 16 and 17 attached to the rear front shaft 14 and the rear rear shaft 15, respectively. In other words, this truck consists of two rear axles. The rear-front shaft 14 and the rear-rear shaft 15 are both suspended by a leaf spring 18, and the rear end of the leaf spring 18 is suspended from the frame 12 via an air spring 19. To explain this configuration in more detail, as shown in FIG. 3, a center portion 20 is formed at the tip of the leaf spring 18, and this center portion 20 is connected to the frame 12 via a bracket 21. It looks like this. On the other hand, an air spring 19 is interposed between the rear end portion of the leaf spring 18 and the frame 12. This air spring 19- is connected to the air tank 23 through the supply/exhaust valve 22.
It is designed to be connected to The electromagnetic coil 24 of the supply/exhaust valve 22 is controlled by a microcomputer 25. microcomputer 25
is connected to a vehicle height sensor 26, and the vehicle height is adjusted in accordance with the detection by this sensor 26. Note that the vehicle height sensor 26 is composed of an ultrasonic sensor. A vehicle height sensor 26 connected to the microcomputer 25 is supported as shown in FIG. That is, the vehicle height sensor 26 is fixed to the support plate 27, and the segment gear 28 is fixed to the support plate 27. Both are rotatably supported by a common pin 29, and the segment gear 28 is connected to the gear 31 of the motor 30.
and is driven by the motor 30. Next, the drive circuit for this motor 30 will be explained with reference to FIG. The drive circuit for this motor 30 is connected to a back switch 32 which is opened when the shift lever is placed in the reverse position.
It is designed to be connected to In addition, back switch 3
2 is a coil 3 that operates the back lamp or buzzer
3 is connected. and switch 32 and coil 33
A pair of coils 34, 35 are respectively connected to the connection points with the coils 34, 35, and each of these coils 34, 35 is adapted to switch a changeover switch 36, 37, respectively. These switches 36 and 37 are adapted to switch the motor 30 between forward and reverse rotation. Further, limit switches 38 and 39 are connected between these switches 36 and 37 and the power supply terminal, respectively. Next, the operation of this vehicle height adjusting device configured as described above will be explained based on the flowchart shown in FIG. 7. As shown in FIG. 1, when unloading the cargo 40 from the truck bed 13, the microcomputer 25 reads the detection output of the vehicle height sensor 26, converts this output into A/D, and uses this value to Make a judgment as to whether or not. When the vehicle is stopped, a set value given in advance to the microcomputer 25 is read, and it is determined whether the actual vehicle height obtained by the sensor 26 deviates from this set value. If it deviates from the set value, the microcomputer 25 opens the supply/exhaust valve 22 via the electromagnetic coil 24, and the air tank 2
3 to the air spring 19, or the compressed air in the air spring 19 is supplied to the air spring 19 through the air supply/exhaust valve 22.
into the atmosphere through the exhaust port. This allows the vehicle height to be adjusted. In this way, the ll! of the truck according to this embodiment! According to the height adjustment device, the height from the ground is directly detected at the rear end of the loading platform 13 by the ultrasonic sensor 26, and the air within one air spring is adjusted accordingly.
The height of the loading platform 13 is changed. Therefore, the bending of the rear end of the cargo platform 13 due to the cargo 40, or the
It is now possible to adjust the vehicle height including the deflection of 716.17, and the rear end of the loading platform 13 and the platform 41
This makes it possible to prevent the occurrence of a step between the two. That is, according to the vehicle height adjustment device according to the present embodiment, since the ultrasonic sensor 26 is provided at the rear end of the loading platform and the height from the ground is directly detected by this sensor 26, the height from the ground is directly detected. It becomes possible to correct the vehicle height including the deflection of the tires and the deflection of the tires. As shown in FIG. 7, this rR^ adjustment device operates even while the truck is running, and in this case, the microcomputer 25 reads the reference level and the ultrasonic sensor The height from the ground detected by No. 26 is compared with this reference level. If the actual vehicle height deviates from the standard driving level, compressed air is supplied into the air spring 19 by the supply/exhaust valve 22 by the same operation as above, or the air spring 19 is compressed. By discharging air, the height of the loading platform 13 is maintained at an appropriate value. Furthermore, the ultrasonic sensor 26 of the vehicle height adjustment device according to this embodiment
is designed to operate as a rear obstacle detection device when the truck is reversing. To explain this operation, when the shift lever is put into the reverse position to move the vehicle backward, the reverse switch 32 is closed as shown in FIG. Therefore, a pair of coils 34
．． 35 are both energized, and the changeover switches 36 and 37 are switched to the position shown in solid lines in FIG. Therefore, a power supply circuit for the motor 30 is formed, and the motor 30 rotates in the normal direction. When the motor 30 rotates forward, the rotation causes the gear 31 and the segment gear 28 to rotate.
, the support plate 27 is rotated counterclockwise about the two bottles as shown in FIG. Accordingly, the ultrasonic sensor 26 is rotated by 901f to face rearward. Note that when the ultrasonic sensor 26 is rotated to a predetermined position, a limit switch 38 shown in FIG. 6 is opened and the motor 30 is stopped. In this way, since the ultrasonic sensor 26 faces rearward when a truck enters or leaves the truck, the ultrasonic sensor 26 faces backward as shown in FIG.
The sensor 6 operates as a detection device for detecting obstacles behind the vehicle, and the vehicle can move backward while checking the rear using the sensor 26. When the truck finishes reversing and the shift lever is returned to the neutral position, the switch 32 shown in FIG. 6 is opened, so that both the coils 34 and -35 are deenergized. Therefore switch 36
．． 37 are respectively switched to the positions indicated by the dotted lines in FIG. sensor 26
changes from the state shown in FIG. 5 to the state shown in FIG. In other words, the vehicle returns to the original position where vehicle height adjustment is performed. [Effects of the Invention] As described above, the present invention provides a sensor near the rear end of the loading platform, uses this sensor to directly detect the height of the loading platform from the ground, and adjusts the vehicle height in conjunction with this detection. It is designed to perform the following actions. Therefore, according to the present invention, it is possible to always maintain the rear end of the loading platform at a predetermined height above the ground regardless of the deflection of the loading platform or frame, the amount of deformation of the tires, etc. It becomes possible to provide a truck equipped with a vehicle height adjustment device convenient for

[Brief explanation of drawings]

FIG. 1 is a side view of a truck equipped with a vehicle height adjustment device according to an embodiment of the present invention, FIG. 2 is a side view of the truck when reversing, and FIG. 3 is a side view showing the rear suspension device of this truck. , Fig. 4 is a front view showing the support mechanism of the ultrasonic wave sensor, Fig. 5 is a front view of the ultrasonic sensor in a rotated state, Fig. 6 is a circuit diagram of the forward/reverse circuit of the motor, and Fig. 7 is a front view showing the support mechanism of the ultrasonic wave sensor. The figure is a flowchart showing the operation of this vehicle height adjustment device, and FIG. 8 is a side view of a conventional truck. In addition, in the symbols used in the drawings, 13...Cargo platform 19...Air spring 22...Intake/exhaust valve 23...Air tank 24...Electromagnetic coil 25...Microcomputer 26...Vehicle height sensor (ultrasonic sensor).

Claims (1)

[Scope of Claims] 1. In an apparatus comprising a loading platform, the height of the loading platform from the ground is detected by a sensor, and the vehicle height is adjusted according to the detection by the sensor, wherein the rear end of the loading platform 1. A vehicle height adjustment device for a truck loading platform, characterized in that the sensor is provided near the section, and the height of the loading platform from the ground is directly detected by the sensor. 2. Vehicle height adjustment of a truck bed according to claim 1, characterized in that the sensor is rotatably supported and a drive means for directing the sensor rearward is provided. Device.