JP3724329B2 - Air suspension adjustment device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a device for adjusting an air suspension provided in a chassis production line for vehicles, particularly trucks.
[0002]
[Prior art]
In vehicles such as trucks and buses, when a so-called air suspension in which a chassis frame is suspended on an axle via an air spring known per se is used, before the manufactured chassis is shipped, an air suspension control mounted on the vehicle is controlled. It is necessary to store the reference vehicle height in the control unit. When the chassis frame is displaced in the vertical direction according to the loading capacity of personnel, cargo, etc. during operation after shipment of the vehicle, the reference vehicle height is a certain vertical distance that the displacement amount is practically acceptable for the reference vehicle height. When the allowable vehicle height value including the allowable value is changed, the control unit supplies drive output to the solenoid valve that controls the height by supplying and discharging compressed air to the air spring, and as a result, This is necessary in order to keep the height of the chassis frame substantially constant regardless of changes in the loading capacity.
[0003]
In the chassis production line, in order to set the above-mentioned reference vehicle height, it is necessary to measure the vertical distance between the axle and the chassis frame with a measuring device outside the vehicle (hereinafter sometimes referred to as an external vehicle height measuring device). There is.
A reference vehicle height setting method in a conventional truck chassis production line will now be described with reference to FIGS. First, in the schematic side view of FIG. 5, reference numeral 10 generally indicates a chassis for a truck. The chassis 10 has a pair of left and right side rails 12 extending in the longitudinal direction of the vehicle and both ends in the vehicle width direction of the left and right sides. A ladder-type chassis frame 14 including a plurality of cross members fixed to the side rails is provided.
[0004]
The chassis frame 14 has a front portion suspended from a front axle 18 via a leaf spring 16, and a rear portion suspended from a rear front shaft 22F and a rear rear shaft 22R via air suspensions 20F and 20R, respectively. A cab C is mounted above the front end portion of the frame 14. As shown in FIG. 6, the air suspension 20R of the rear rear shaft 22R includes a leaf spring 28 whose front end is pivotally supported by the side rail 12 via a spring bracket 24 and a pivot pin 26, and a vehicle. A well-known air interposed between the end of the cross beam 30 that extends in the width direction and has both ends fixed to the rear ends of the left and right leaf springs 28 and the lower surface of the side rail 12. The rear rear shaft 22R is fixed to the intermediate portion in the front-rear direction of the leaf spring 28 by U bolts 34 at both ends in the vehicle width direction. Further, the lower end of the shock absorber 36 is pivotally attached to the rear rear shaft 22R or the leaf spring 28 in the vicinity of the fixed portion, and the upper end of the shock absorber 36 is pivotally attached to an appropriate position of the chassis frame 14 above the rear rear shaft 22R. Yes. As shown in FIG. 5, the air suspension 22F of the rear front shaft 22F has a structure substantially similar to the air suspension 22R of the rear rear shaft 22R.
[0005]
A height sensor 38 is disposed between the rear rear shaft 22R and the chassis frame 14 to measure the vehicle height. As shown in the enlarged side view of FIG. 7, the height sensor 38 has a rod 40 whose lower end is pivotally attached to the rear rear shaft 22R and arranged in the vertical direction, and only a part of the height sensor 38 is conceptual in the drawing. The sensor 44 is fixed at a proper position on the chassis frame 14 and generates an output signal of an electrically variable amount corresponding to the rotation angle of the input shaft 42, and one end is fixed to the input shaft 42 of the sensor 44 and the like. And an operating arm 46 pivotally attached to the upper end of the rod 40. The rod 40 is extended by rotating a nut member 48 interposed in the middle portion in the longitudinal direction in one direction. It is a variable length member that is shortened by rotating in the opposite direction.
[0006]
The height sensor 38 detects the relative change in the vertical direction of the rear rear shaft 22R with respect to the chassis frame 14, and supplies the output signal of the sensor 44 to the control unit 50 for air suspension control mounted on the cab C. In addition, the vertical distance between the rear rear shaft 22R and the chassis frame 14 is substantially determined by the height of the air spring 32. Accordingly, in this specification, the term vehicle height means the height of the air spring 32, that is, the vertical distance H between the upper surface of the cross beam 32 and the lower surface of the side rail 12 (see FIG. 6). It is.
[0007]
In a vehicle equipped with many conventional air suspensions, the height sensor 38 is provided on the axle for adjusting the vehicle height, that is, in the case of the rear rear shaft 22R in the vehicle width direction substantially central portion and the chassis frame 14 or the chassis frame above it. One is arranged between the fixed member. In this case, the height sensor 38 cannot detect the difference in vehicle height between the left and right side rails 12 of the chassis frame 14. Therefore, as shown in FIG. 8, the left and right side rails 12A and 12B of the chassis frame 14 (hereinafter, when it is necessary to distinguish the left and right in the same manner, the member A on the left side of the vehicle is denoted by A after the above symbols. Further, height sensors 38A and 38B are arranged in the vicinity of the left and right air springs 32A and 32B, respectively, in order to control the height of the right member. An output signal is input to the on-vehicle air suspension control unit 50, and the solenoid valves 52A and 52B for controlling the supply and discharge of the compressed air of the air springs 32A and 32B are operated by the drive output of the control unit 50, respectively. In this case, the following problems are encountered in adjusting the vehicle height before shipment on the chassis production line. In FIG. 8, reference numeral 54 denotes an in-vehicle air tank as a compressed air source connected to the electromagnetic valves 52A and 52B. The air tank 54 stores the compressed air discharged from the air compressor driven by the vehicle engine. The Further, the solenoid valves 52A and 52B simultaneously supply and discharge compressed air to and from the air spring 32 of the rear front shaft 22F disposed just before the rear rear shaft 22R.
[0008]
The vehicle-mounted height sensors 38A and 38B originally detect a relative change in the vehicle height, and cannot detect the absolute vehicle height. The air springs 32A and 32B include Since there is an unavoidable error in the manufacturing technology, each of the rising ends which are fully extended by supplying compressed air or the compressed air inside is exhausted and the respective top plates contacting the side rails 12A and 12B are incorporated. The vehicle height at the descending end contracted until it abuts against the bump stopper may be different from right to left. Therefore, if the vehicle height is adjusted based on the ascending end or the descending end, the chassis frame 14 is inclined in the left-right direction. For some reason, it is inappropriate to adjust the vehicle height using the above-described vehicle-mounted height sensors 38A and 38B.
[0009]
Therefore, conventionally, as shown in FIG. 5, a diagnosis controller 56 for adjustment and fault diagnosis is connected to a control unit 50 for air suspension control mounted on the cab C, and also shown in FIG. As shown in the figure, an artificially-reading external vehicle height measuring device 58 equivalent to a normal ruler is arranged in the vicinity of the air springs 32A and 32B, and the operator operates the diagnosis controller 56 via the vehicle-mounted control unit 50. The solenoid valves 52A and 52B are actuated, the compressed air of the air springs 32A and 32B is supplied and discharged to expand or contract, and the vehicle height is brought close to a predetermined reference value for the vehicle. Read the scale of the height measuring instrument 58 and repeat the work of observing and measuring the left and right vehicle heights. After the operation of the controller 56 and the visual measurement of the external vehicle height measuring device 58 are repeated several times, when the vehicle height becomes the reference value for both the left and right, the diagnosis controller 56 is operated, and the height sensor 38A at that time is operated. , 38B sensor output signals are stored in the in-vehicle control unit 50 as reference values.
[0010]
In the conventional vehicle height adjustment method, it is necessary to repeatedly operate the diagnosis controller 56, and each time a visual measurement of the external vehicle height measuring device 58 is required, so that the work procedure is extremely complicated and requires time and effort. In particular, when chassis of different vehicle types are manufactured on the same production line, there is a problem that the work procedure becomes more complicated because the reference vehicle height is different. Further, since the conventional external vehicle height measuring device 58 is equivalent to a normal ruler, there is a drawback that errors due to the operator are likely to occur, such as how to apply it and reading numerical values.
[0011]
[Problems to be solved by the invention]
The present invention eliminates the above-mentioned problems and disadvantages of the conventional air suspension adjustment method, has a remarkably simple work procedure, and can perform the required air suspension adjustment work accurately and at low cost in a short time. The main purpose is to provide an adjusting device.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an external vehicle height measuring device for measuring a distance between a vehicle axle and a chassis frame on a production line and outputting a signal representing the distance, and the axle and chassis frame. And an air supply / discharge device for controlling the height of the air spring by supplying compressed air into the air chamber of the air spring and discharging the compressed air in the air chamber A height sensor that is disposed in the vehicle and detects the height of the air spring by a relative value with respect to a reference vehicle height, and the air spring is extended or contracted by the air supply / discharge device so that the axle and the chassis frame are extended. A signal indicating that the vehicle is the reference vehicle height when the input value from the external vehicle height measuring device is measured to be a predetermined value. A vehicle height adjustment device that receives power and a detection value of the height sensor, and when the signal indicating the reference vehicle height is input from the vehicle height adjustment device, the detection value of the height sensor is recognized as the reference vehicle height. A control unit; Receives the parameters in the in-vehicle control unit, determines the vehicle type, determines the reference vehicle height, receives vehicle height data from the external vehicle height measuring device, compares the vehicle height data with the reference vehicle height, An external control unit that transmits a signal for controlling the air supply / discharge device to the vehicle-mounted control unit so as to approach the reference vehicle height An air suspension adjusting device is proposed.
In the present invention, the air spring is interposed between a pair of left and right side rails extending in the vehicle front-rear direction of the chassis frame and the axle, and the left and right air springs are adjacent to the left and right air springs. It is preferable that a height sensor is provided and the predetermined value is an allowable vehicle height value obtained by adding an appropriate vertical allowable value to a preset target vehicle height value.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 4 and FIG. Note that components and parts that are substantially the same as or correspond to the components and parts of the vehicle described with reference to FIGS. Description is omitted.
First, FIG. 1 is a schematic side view showing an operation process for adjusting an air suspension of a chassis 10 in a truck chassis production line. In the illustrated chassis 10, the rear front shaft 22F and the rear rear shaft 22R suspend the chassis frame 14 via air suspensions 20F and 20R, as in the chassis of FIG. The chassis 10 shown in FIG. 1 is different from that shown in FIG. 5 in that the front axle 18 is provided with an air spring substantially similar to the above, and is exemplified as a so-called all-wheel air suspension chassis. Further, although not shown in FIG. 1, both ends of the rear rear shaft 22R in the vehicle width direction are shown in FIGS. 6 to 8 between the vicinity and the vicinity of the left and right side rails 12 of the chassis frame 14. Left and right height sensors 38A and 38B having substantially the same structure as that of the vehicle are provided, and a similar height sensor is provided between the chassis frame 14 and a substantially central portion of the front axle 18 in the vehicle width direction.
[0014]
In FIG. 1, reference numeral 60 indicates the detailed structure shown in FIGS. 2 and 3, and an automatically operating external vehicle height measuring device for the rear axle 22 </ b> R, and 62 is an automatically operating external vehicle for the front axle 18. A height measuring device, 64 is a vehicle inspection pit dug below the factory floor FL along the chassis production line, and 66 is a vehicle height adjusting device provided at a position that does not obstruct the passage of the chassis 10 on the side of the chassis production line. , 68 is a relay box that receives the output signal of the external vehicle height measuring device 60 via the connection cable 70 and transmits it to the vehicle height adjusting device 66 via the transmission cable 72, and 74 is the output of the external vehicle height measuring device 62. It is a relay box that receives a signal via a connection cable 76 and transmits the signal to the vehicle height adjusting device 66 via a transmission cable 78.
The vehicle height adjusting device 66 is connected to the vehicle-mounted air suspension control unit 50 via a communication cable 80 and has an external control unit 82 capable of transmitting / receiving information to / from the control unit 50. I have.
[0015]
The structure of the external vehicle height measuring device 60 for the rear rear shaft 22R will be described with reference to FIGS. The external vehicle height measuring device 60 includes a base 86 provided with a toggle clamp 84, a lower end fixed to the base 86 and extending upward, and a number of scales 88 (in FIG. A scale 90 provided with only a part of the scale 90, a guide rail 92 fixed to one side of the scale 90, a slider 94 slidably fitted to the guide rail 92, The slider 94 is fixed to the slider 94, and the level of the scale 88 is detected at the end of the slider 96 on the scale 90 side to detect the height from the reference surface 98 of the base 86. A photoelectric scale sensor 100 is provided, and a support arm 102 projects from the air spring 32 and the side rail 12 side. On the lower side surface of the support arm 102, there is provided an engagement element 104 that contacts the upper surface of the top plate 32a of the air spring 32 that contacts the lower surface of the lower flange 12f of the side rail 12. An appropriate number (two in the case of illustration) of suction cups 106 for holding the sliding table 96 at the vehicle height measuring position by being vacuum-sucked to the web 12w of the rail 12 is provided. Further, the slide table 96 is provided with a terminal box 108 for sending a signal output indicating the vehicle height of the scale sensor 100 to the external control unit 82 via a connection cable and a relay box 68, and for measuring the external vehicle height. A handle 110 is provided so that it is convenient for carrying the container 60 and handling it when attaching and detaching.
[0016]
By measuring the distance between the reference surface 98 of the base 86 in contact with the upper surface of the cross beam 30 and the lower surface of the engagement element 104 in contact with the upper surface of the top plate 32a of the air spring 32, the height of the air spring 32 is measured. That is, the passenger compartment H can be accurately measured. The toggle clamp 84 of the base 86 includes a toggle link (not shown) that connects the operation arm 84a and the clamp arm 84b to form a toggle mechanism, and is shown by a one-dot chain line in FIG. By rotating the operation arm 84a counterclockwise from the rest position, the air suspension 20R is formed by the upper arm 86a having the reference surface 98 of the base 86 and the clamp arm 84b as shown by a solid line in the drawing. The leaf spring 28 and the cross beam 30 are sandwiched, and the external vehicle height measuring device 60 can be held in a correct measurement position in cooperation with the suction cup 106. The external vehicle height measuring device 62 that measures the vehicle height on the front axle 18 side is such that the vehicle height to be measured is the distance between the upper surface of the front axle 18 and the lower surface of the lower flange 12f of the side rail 12, and Since the vehicle inspection pit 64 is attached / detached, there is a slight difference in shape and structure, but in principle, it has the same structure as the external vehicle height measuring device. As shown by a two-dot chain line in FIG. 2, the air spring 32 includes a gantry 32b that is fixed to the cross beam 30 by mounting bolts (not shown), an upper peripheral portion of the gantry 32b, and the top plate 32a. A rubber cylindrical stretchable wall 32d that is interposed therebetween and limits the air chamber 32c, and a rubber bump stopper 32e fixed to the upper surface of the gantry 32b are provided.
[0017]
When the chassis 10 along the production line reaches the vehicle height adjustment process shown in FIG. 1, an external vehicle height measuring device in the state shown in FIG. 2 is formed at the rear end portions of the leaf springs 28 in the left and right air suspensions 20R of the rear rear shaft 22R. When the chassis 10 is an all-wheel air suspension, an external vehicle height measuring device 62 is attached between the front axle 18 and the side rails 12 of the chassis frame 14. The control unit 50 for air suspension control mounted on the cab C and the external control unit 82 of the vehicle height adjusting device 66 are connected by a communication cable 80. As shown in FIG. 5, in the case where the chassis 10 is a vehicle type in which an air suspension is provided only on the rear axle and the chassis 14 is suspended through the leaf spring 16, of course, the external vehicle height measuring device 62 is used. Can not be installed. Accordingly, the vehicle height adjustment procedure for the left and right air suspensions 20R of the rear rear shaft 22R will be described with reference to the flowchart of FIG.
[0018]
After the installation of the external vehicle height measuring device 60 and the connection of the communication cable 80 are completed, when the start switch of the vehicle height adjusting device 66 is closed, the external control unit 82 starts operating and the program starts. Step S of FIG. ₁ , The parameters of the chassis 10 whose vehicle height is adjusted are sent from the in-vehicle control unit 50 to the external control unit 82, and the vehicle height target value of the rear axle 22R, which is preset according to the vehicle type of the chassis 10, is read. . Next step S ₂ Then, all the air springs 32 of the air suspensions 20R and 20F of the rear rear shaft 22R and the rear front shaft 22F are exhausted. The exhaust command is sent from the external control unit 82 to the in-vehicle control unit 50, and the in-vehicle control unit 50 supplies an output for driving the electromagnetic valves 52A and 52B constituting the air supply / exhaust device to the exhaust position in FIG. The air spring 32 continues to be exhausted until the value of a pressure sensor (not shown) attached to an appropriate position of the air supply / discharge device does not change.
[0019]
Since the solenoid valves 52A and 52B discharge the compressed air in the air chambers 32e of the left and right air springs 32 of the rear front shaft 22F and the rear rear shaft 22R, each air spring 32 contracts and the top plate 32a descends to bump stopper. The external vehicle height measuring device 60 detects the contracted heights of the left and right air springs 32 and transmits a signal output corresponding to each height to the external control unit 82. Next step S ₃ The external control unit 82 compares the vehicle height target value with either the left or right, for example, the vehicle height value represented by the signal output of the left external vehicle height measuring device 60, When an instruction is given to provide an output for driving the solenoid valves 52A and 52B of the air supply / discharge device to the supply position, and as a result, the left air spring 32A extends and its height exceeds the vehicle height target value, the external Conversely, the control unit 82 gives a command to drive the electromagnetic valves 52A and 52B to the exhaust position to the vehicle-mounted control unit 50, and brings the vehicle height close to the vehicle height target value.
[0020]
Step S ₄ It is then determined whether the left air spring 32A has reached the vehicle height target value. ₃ Then, the compressed air is supplied to and discharged from all the air springs 32 until the left air spring 32A matches the vehicle height target value. If the left air spring 32A becomes the vehicle height reference value, the step is S ₅ Then, it is determined whether or not the height of the right air spring 32B is within a predetermined allowable vehicle height value obtained by adding a vertical allowable value, for example, plus or minus 5 mm, to the vehicle height target value. If the height of the right air spring 32B is within the allowable vehicle height value, the difference between the left and right vehicle height values is in a range where there is no practical problem. ₆ Proceed to
[0021]
On the other hand, if the height of the right air spring 32B exceeds the allowable vehicle height value and is too high or too low, the step is S ₂₀ Proceed to Step S ₂₀ Then, if the right air spring 32B is too high, the external control unit 82 determines this and sends a command signal to exhaust from all the air springs 32A and 32B to the in-vehicle control unit 50, and conversely, the right air spring 32B is too low. In this case, the external control unit 82 determines this and transmits a command signal for supplying air to all the air springs 32A and 32B to the in-vehicle control unit 50. The in-vehicle control unit 50 gives an output for driving the solenoid valves 52A and 52B to the exhaust position or the supply position in response to the command signal. As a result, the right air spring 32B is adjusted to a height that falls within the allowable vehicle height value, while the left air spring 32A that is at the vehicle height target value deviates from the target vehicle height value in the correction direction. , Step S ₂₁ It is then determined again whether or not the height of the left air spring 32A is within the allowable vehicle height value. If YES, step S ₅ If both the left and right air springs 32A and 32B are within the allowable vehicle height value, step S ₆ Proceed to In spite of the height correction in step 20 above, no appropriate adjustment is made for any reason, and step S ₂₁ If NO is determined in step S, step S ₂₂ An error is displayed.
[0022]
Returning to the main routine again, the above step S ₆ Then, it is checked whether the outputs of the left and right height sensors 38A and 38B corresponding to the left and right air springs 32A and 32B, respectively, confirmed to be within the allowable vehicle height value in the previous step, are within the allowable value. It is done. As apparent from FIGS. 7 and 8, the outputs of the height sensors 38A and 38B convert the vertical displacement of the rod 40 that responds to the linear displacement of the rear rear shaft 22R into the rotation angle of the operating arm 46 that performs an arc motion. Since the output substantially proportional to the rotation angle is generated by the sensor 44, the output of the actuating arm 42 that can obtain a signal output that substantially responds to the linear displacement of the rear rear shaft 22R, that is, the height of the air spring 32 It is preferable in terms of control accuracy that the angle range is a certain angle range above and below the horizontal, for example, about 20 degrees above and below, and the sensor output in this range is an allowable value. This step S ₆ If YES, the sensor outputs, that is, the detected values of the left and right height sensors 38A, 38B are both within the allowable values, the step is S ₇ Proceed to Note that the outputs of the left and right height sensors 38A and 38B do not have to be the same, as long as each is within the allowable value.
[0023]
Step S ₆ If any of the detected values of the left and right height sensors 38A, 38B is out of the allowable value, the step is S ₂₃ Proceed to, and abnormal display will be made. Step S ₂₂ When an abnormal display is made in step S, and step S ₂₃ If an error is displayed at, it is not possible to perform treatment on the production line within the range of the cycle time. ₂₂ Then, investigate the cause and replace the malfunctioning air spring, for example. ₂₃ Then, by loosening the lock nut screwed to the upper and lower ends of the nut member 48 of the rod 40 and rotating the nut member 48, the operating arm 46 is displaced to the horizontal position or an angular position close thereto, and the sensor 44 Correct the output so that it is within the tolerance.
Next, the above step S ₇ Then, a signal indicating a neutral position that simulates the signal output of the left and right height sensors 38A and 38B, that is, the detected value as the reference vehicle height, is transmitted to the in-vehicle control unit 50 and stored.
[0024]
The program is further S ₈ Here, a command signal for supplying air to all the air springs 32 of the rear front shaft 22F and the rear rear shaft 22R is transmitted from the external control unit 82 to the in-vehicle control unit 50, and the electromagnetic valves 52A constituting the air supply / discharge device A shock absorber (abbreviated as “shock ABS” in the flowchart) 36 is extended to all the air springs 32 through 52B and is supplied with air until its length does not change. Next step is S ₉ Then, the exhaust control of all the air springs 32 is instructed to the in-vehicle control unit, and the exhaust is performed until the left shock absorber of the rear rear shaft 22R becomes a predetermined dimension, for example, 20 mm shorter than the extended position as an index. It is. This reduction of the shock absorber 36 is automatically detected when the deflection of the external vehicle height measuring device 60 is substantially lowered by 20 mm. Next, at step 10, the signal output of the height sensors 38A, 38B at this position is transmitted to and stored in the vehicle-mounted control unit 50 as the upper limit position for vehicle height control.
[0025]
Next step is S ₁₁ The command to exhaust all the air springs 32 of the rear front shaft 22F and the rear rear shaft 22R is transmitted from the external control unit 82 to the in-vehicle control unit 50, and all the air springs 32A and 2B of the air supply / discharge device The air spring is exhausted until the shock absorber 36 contracts and there is no change in its length. Then, step S ₁₂ The signal output of the height sensors 38A and 38B in a state where all the air springs 32 are contracted is transmitted to and stored in the vehicle-mounted control unit 50 as the lower limit position in the vehicle height control.
[0026]
Step S above ₂₂ And step S ₂₃ When the chassis 10 is turned off and the chassis 10 is line-off, only a few of all chassis flowing through the chassis production line need to be specially treated. ₁ ~ S ₁₂ It flows smoothly. During this time, the air suspension adjustment work is automatically performed except for the attachment and detachment of the external vehicle height measuring device 60. Therefore, the work procedure is simple and the labor and time can be greatly reduced. There is an advantage that can be greatly reduced.
[0027]
In the case where the chassis 10 is an all-wheel air suspension as shown in FIG. 1, of course, an external vehicle height measuring device is used to control the height of the air spring 32 of the front axle 18 to the vehicle height target value. 62 must be installed. In the case of an all-wheel air suspension, the axle weight of the front axle 18 is significantly smaller than the axle weight of the rear axle (in the case of FIG. 1, the rear front axle 22F and the rear rear axle 22R) at the time of loading. Accordingly, the height sensor 38 has a substantially central portion in the vehicle width direction of the front axle 18 and a substantially central portion in the vehicle width direction of the chassis frame 14. In this case, the vehicle height adjustment of the front axle 18 is performed in step S related to the left and right air springs 32A and 32B in the flowchart of FIG. ₅ , S ₂₀ , S ₂₁ The same process may be executed using either the left or right, for example, the left air spring 32 alone as an index. In addition, when the rear axle of the chassis 10 to be adjusted is a single axle, it is obvious that the vehicle height can be adjusted according to the flowchart of FIG. Similar to the above-described front axle, the case where one height sensor 38 is provided at a substantially central portion in the vehicle width direction is substantially the same.
[0028]
In addition, by providing left and right height sensors 38A and 38B corresponding to the left and right air springs 32A and 32B in the rear rear shaft 22R or the single rear axle, respectively, a chassis that has been line-off after the vehicle height adjustment is marketed. The air supply / discharge device is driven on the basis of the neutral position corresponding to the target vehicle height value of the air springs 32A and 32B stored in the in-vehicle control unit 50, and the upper limit position and the lower limit position, respectively. The vehicle height is adjusted by extending or contracting 32 at the same time or separately on the left and right. For example, when the chassis frame 14 is tilted to the left or right due to uneven accumulation or the like, and any one of the air springs 32 extends or shortens beyond the allowable value (for example, ± 5 mm) from the neutral position, the air of the air spring Since the working compressed air in the chamber 32C is exhausted or supplied into the air chamber 32c, and a substantially constant vehicle height is maintained at all times, it is possible to improve running stability and damage of loaded cargo. And there is an advantage that can prevent the load from slipping.
[0029]
【The invention's effect】
As described above, the air suspension adjusting device according to the present invention measures the distance between the axle of the vehicle and the chassis frame in the production line and outputs a signal representing the distance, The height of the air spring is controlled by supplying the compressed air into the air chamber of the air spring interposed between the axle and the chassis frame, and discharging the compressed air in the air chamber. An air supply / discharge device, a height sensor disposed in the vehicle for detecting the height of the air spring based on a relative value with respect to a reference vehicle height, and the air spring is extended or contracted by the air supply / discharge device. When the distance between the axle and the chassis frame is changed and the input value from the external vehicle height measuring device is measured to be a predetermined value, the reference vehicle height A vehicle height adjustment device that outputs a signal indicating that there is a signal, and a detection value of the height sensor is taken in, and the detection value of the height sensor when the signal indicating the reference vehicle height is input from the vehicle height adjustment device is a reference It has a vehicle-mounted air suspension control unit that recognizes the vehicle height, and it saves labor and time with a simple procedure for adjusting the vehicle height of the air suspension in the chassis production line, greatly reducing work costs. There are benefits to get.
[0030]
In the present invention, the air spring is interposed between the pair of left and right side rails extending in the vehicle front-rear direction of the chassis frame and the axle, and is adjacent to the left and right air springs. Preferably, the predetermined value is an allowable vehicle height value obtained by adding an appropriate vertical allowable value to a preset target vehicle height value. With this configuration, the driving safety during operation after adjusting the vehicle height is preferable. There is an advantage that the vehicle height can be effectively adjusted for unevenness and the like.
[Brief description of the drawings]
FIG. 1 is a schematic side view illustrating a preferred embodiment of the present invention.
2 is a front view showing a detailed structure of an external vehicle height measuring device 60 in FIG. 1. FIG.
FIG. 3 is a plan view taken along line III-III in FIG. 2;
4 is a flowchart showing an operation mode of an external control unit 82 in FIG. 1. FIG.
FIG. 5 is a schematic side view for explaining a vehicle height adjustment mode of a conventional truck chassis having a rear axle provided with an air suspension.
6 is an enlarged side view showing an extracted air suspension 20R of the rear rear shaft 22A in FIG. 5. FIG.
7 is an enlarged side view of the height sensor 38 in FIG. 6. FIG.
FIG. 8 is a conceptual configuration diagram of an air supply / discharge device when height sensors are provided on the left and right air suspensions of the rear axle in the chassis shown in FIGS. 1 and 5, respectively.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Truck chassis, 12 ... Side rail, 14 ... Chassis frame, 18 ... Front axle, 20F and 20R ... Air suspension, 22F and 22R ... Rear front axle and rear rear axle (rear axle), 28 ... Leaf spring, 30 ... Cross beam, 32 ... Air spring, 36 ... Shock absorber, 38 ... Height sensor, 50 ... In-vehicle control unit, 52A and 52B ... Solenoid valve (air supply / discharge device), 56 ... Diagnostics controller, 58 ... Artificial reading external vehicle height Measuring devices 60 and 62 ... automatic external vehicle height measuring device, 66 ... vehicle height adjusting device, 82 ... external control unit.

Claims (2)

An external vehicle height measuring device for measuring a distance between a vehicle axle and a chassis frame in a production line and outputting a signal representing the distance;
An air spring interposed between the axle and the chassis frame;
An air supply / discharge device for controlling the height of the air spring by supplying compressed air into the air chamber of the air spring and discharging the compressed air in the air chamber;
A height sensor that is disposed in the vehicle and detects a height of the air spring by a relative value with a reference vehicle height;
When the air spring is extended or contracted by the air supply / discharge device to change the distance between the axle and the chassis frame, and the input value from the external vehicle height measuring device is measured to be a predetermined value. A vehicle height adjusting device that outputs a signal indicating that it is the reference vehicle height;
An in-vehicle control unit that takes in the detection value of the height sensor and recognizes the detection value of the height sensor as a reference vehicle height when a signal indicating the reference vehicle height is input from the vehicle height adjustment device;
Receives the parameters in the in-vehicle control unit, determines the vehicle type, determines the reference vehicle height, receives vehicle height data from the external vehicle height measuring device, compares the vehicle height data with the reference vehicle height, An external control unit for transmitting a signal for controlling the air supply / discharge device to the vehicle-mounted control unit so as to approach the reference vehicle height;
An apparatus for adjusting an air suspension , comprising: The air spring is interposed between a pair of left and right side rails extending in the vehicle longitudinal direction of the chassis frame and the axle, and left and right height sensors are disposed adjacent to the left and right air springs, respectively. 2. The air suspension adjusting device according to claim 1, wherein the predetermined value is an allowable vehicle height value obtained by adding an appropriate vertical allowable value to a preset target vehicle height value.

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