JPH0511047Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Industrial application field) By changing the vehicle body load applied to the vehicle wheel axle,
This improves drivability on muddy ground and snowy roads.

(Prior art) Vehicles with three or more axles such as large trucks and buses, that is, large trucks 1 as shown in FIG.
There is a vehicle in which a front wheel axle 2, a rear front wheel axle 3, and a rear rear wheel axle 4 are arranged along the width direction of the vehicle, and driving force from an on-vehicle engine is transmitted to the rear front wheel axle 3 to drive the vehicle.

Therefore, in such a vehicle, the vehicle body load applied to the rear wheels is shared between the rear front wheel axle 3 and the rear rear wheel axle 4 to support the vehicle body 7.

However, the driving force F of the vehicle is due to the tires 5 and the road surface 6.
It is the product of the friction coefficient μ and the load P applied to the rear and front wheel axles 3.

Therefore, on difficult roads such as muddy lands and snowy roads where the friction coefficient μ is small, the driving force F may become smaller than the vehicle running resistance force F', resulting in a problem that the vehicle cannot run.

(Purpose of the invention) The present application provides that when the above-mentioned vehicle enters the road,
A part or most of the vehicle body support force applied to the rear rear wheel axle 4 is transferred to the rear front wheel axle 3, which is the driving wheel axle, to increase the load P on the rear front wheel axle 3 and increase the driving force F. It also allows the vehicle to escape from snowy roads, etc.

(Structure of the invention) In the present application, the rear axle is constituted by a plurality of axles consisting of a driving wheel axle and a non-driving wheel axle, which suspend the vehicle body by means of a fluid suspension, and the fluid suspension of the non-driving wheel axle is In a vehicle in which the vehicle body support load of the driving wheel axle is increased by reducing the pressure, a first port communicating with the fluid pressure source side, a second port communicating with the fluid suspension of the non-driving wheel axle, and a fluid discharge port are provided. a solenoid valve having a third port, which normally closes the third port and communicates the first port and the second port; a pressure reducing valve having a pressure reducing port for discharging fluid in the fluid suspension of the driving wheel axle; and actuating the solenoid valve to close the first port and the second port.
a manually operated set switch that communicates the port with the third port; a pressure detection means that detects when the pressure within the fluid suspension of the drive wheel shaft reaches a predetermined maximum pressure; The pressure reducing valve is operated to communicate the pressure reducing port with the third port, and when the pressure detecting means detects the predetermined maximum pressure, the pressure reducing valve is operated to connect the third port and the pressure reducing port. The gist of the present invention is a vehicle body load adjustment device for a wheel axle, characterized in that it is comprised of a pressure reduction control means for cutting off communication with the vehicle and maintaining this state.

According to the present application, the fluid in the fluid suspension is reduced by reducing the fluid pressure in the fluid suspension mounted on a non-driving wheel axle of a vehicle having a plurality of wheel axles on which the vehicle body is suspended by the fluid suspension. This has the effect of being able to transfer the vehicle body load that was on the depressurized wheel axle to the drive wheel axle.

That is, when the manually operated set switch is operated, the solenoid valve is actuated, causing the second port communicating with the fluid suspension of the non-driving wheel axle and the third port connected to the pressure reducing valve to become continuous, and the pressure reducing valve is actuated to establish communication between the third port of the solenoid valve and a pressure reduction port for discharging fluid in the fluid suspension of the non-driving wheel axle. Therefore, the fluid in the fluid suspension of the non-driving wheel axle passes through the second and third ports of the solenoid valve and is released from the pressure reducing port of the pressure reducing valve, increasing the pressure in the fluid suspension of the driving wheel axle. This increases the vehicle body support load on the drive wheel axle.

When the pressure detection means detects that the pressure in the fluid suspension of the drive wheel shaft has reached a predetermined maximum pressure, the pressure reduction control means operates the pressure reduction valve to establish communication between the pressure reduction port and the third port of the solenoid valve. This state is maintained by cutting off the pressure in the fluid suspension of the non-driving wheel axle, so that the pressure in the fluid suspension of the non-driving wheel axle is maintained at the reduced pressure state at this time, and the pressure in the fluid suspension of the driving wheel axle is reduced to the predetermined maximum pressure. will be held.

Therefore, according to the present invention, when the manually operated set switch is operated, the pressure in the fluid suspension of the drive wheel shaft can be increased to a predetermined maximum pressure and maintained at that state. It is possible to reliably secure the driving force of the vehicle in etc.

(Embodiment) A detailed description will be given with reference to the drawings. Fig. 2 shows an embodiment of the present invention, in which reference numerals 2L and 2R denote fluid suspensions provided on the front wheel axle 2 shown in Fig. 1, arranged approximately symmetrically with respect to the center of the vehicle, and suspending the vehicle body 7. Reference numeral 8L or 8R denotes a supply valve 10 arranged downstream of an air tank 9, which is a fluid pressure source, and the air suspension 2L or 2R.
When the air suspensions 2L and 2R are compressed due to an increase in the load on the vehicle body 7 and the clearance between the vehicle body 7 and the front axle 2 becomes smaller than a set value, the leveling valves 8L and 8R supply air from the air tank 9 to the air suspensions 2L or 2R to expand the air suspensions 2L and 2R and maintain the clearance between the vehicle body and the front axle 2 at a specified value.

Also, if the gap between the vehicle body 7 and the front wheel axle 2 becomes larger than the set value, the air suspension 2L or 2R
This air is discharged into the atmosphere from the leveling valve 8L or 8R to maintain the gap at the set value. Reference numeral 11 is a leveling valve for the rear wheel axle (a generic term for the rear front wheel axle 3 and the rear rear wheel axle 4);
Both the structure and operation are substantially the same as the leveling valves 8L and 8R disposed on the front wheel axle 2.

Codes 3LF and 3LR are on the left side of the rear front wheel axle 3, 3
RF and 3RR are air suspensions disposed on the right side of the rear front wheel axle 3, 4L on the left side of the rear rear wheel axle 4, and 4R on the right side of the rear rear wheel axle 4, respectively.

Code 12 is air suspension 3LF, 3
A normally open pressure switch that turns on when the air pressure of LR, 3RF, and 3RR exceeds the set value.
This serves as pressure detection means.

Reference numeral 13 is provided in the driver's seat (not shown), and the power supply 1 is turned on by turning on a set switch 14 which has a built-in pilot lamp 15.
This is a solenoid valve that operates when energized with 6. The same solenoid valve 1
3 is a first port A that communicates with the air tank 9 via the leveling valve 11 and the supply valve 10; B is a second port that communicates with the air suspensions 4L and 4R; Each has a third port C that communicates with a pressure reducing valve 17 that releases air to the atmosphere. Also, the solenoid valve 13 is B- when energized.
C. When the power is off, A and B are connected. The pressure reducing valve 17 having a pressure reducing port E is connected to the electromagnetic coil 1 for actuating the pressure reducing valve 17 via a self-holding relay 18, which will be described later, when the set switch 14 is turned ON.
7' is energized to operate. The pressure reducing valve 17 is energized
When ON, ports D and E communicate with each other, and when power is OFF, ports F and E communicate with each other.

A self-holding relay 18, which serves as pressure reduction control means, is disposed at a power contact H, a contact K connected to the pressure reducing valve 17, and a meter plate 19 on the driver's seat, and the air suspensions 4L and 4R of the rear wheel axle 4 are depressurized. Pilot lamp 20 and pressure reducing valve 1 to indicate that
7 and a contact J connected to an excitation coil 21 that prevents energization to 7, and the contacts HK are normally connected by a spring force (not shown).

Reference numeral 22 receives a signal from a speed sensor 23 and indicates that the vehicle 1 is traveling at a speed greater than a specified value (15 in this embodiment).
This is a safety relay that cuts off the power supply circuit of this device using the current from the speed control 24 when the speed reaches Km/H, and is normally a closed circuit. Also, code 27 is air suspension 4
This is a throttle valve that controls the air pressure of R and 4L so that it does not drop suddenly.

The operation of this device will be explained. When the vehicle 1 enters a muddy or snowy road, the driver turns on the set switch 14, and the current flows as follows: power supply 16 → safety relay 22 → set switch 14 → *1, *2, *
3 *1 The pilot lamp lights up to indicate that the set switch is ON *2 Operate the solenoid valve 13 to connect B and C.

*3 Self-holding relay contact H→contact K→pressure reducing valve 17 is activated and D-E communicate.

Air suspension 4L and 4 for rear rear wheel axle 4
The air in R is connected to B-C of solenoid valve 13 and pressure reducing valve 1.
It is released into the atmosphere through D-E of 7.

Therefore, the air pressure in the air suspensions 4L and 4R decreases, and the vehicle body load acting on the rear rear wheel axle 4 decreases. Therefore, the decrease in the vehicle body load is transferred to the air suspensions 3LF, 3LR, 3RF, and 3RR of the rear front wheel axle 3, and when the air suspensions are compressed and the distance between the vehicle body 7 and the rear front wheel axle 3 becomes smaller. , the leveling valve 11 operates to supply high-pressure air from the air tank 9 to the air suspensions 3LF, 3LR, 3RF, and 3RR so that the gap between the vehicle body 7 and the rear front wheel axle 3 reaches a set value.

When the vehicle body load on the rear rear wheel axle 4 moves to the rear front wheel axle 3 by a set amount, the amount of movement is applied to the air spring 3LF,
It is detected by changes in air pressure in 3LR, 3RF, and 3RR (in this case, the air pressure becomes higher). That is, the pressure switch 12 is turned on when the air pressure in the air suspensions 3LF, 3LR, 3RF, and 3RR reaches a set value.

Then, the current flows from the set switch 14 to the pressure switch 12 to the excitation coil 21 of the self-holding relay 18, and the contacts of the self-holding relay 18 change from H-K to H.
-J, the power to the pressure reducing valve 17 is cut off, ports F-E of the pressure reducing valve 17 are communicated, and port D is closed, stopping air discharge from the air suspensions 4R and 4L, and The transfer of the vehicle body load from the rear wheel axle 4 to the rear front wheel axle 3 is completed.

On the other hand, the current of the self-holding relay 18 flows in the following order: set switch 14 → contact H of self-holding relay 18 → contact J → *1, *2 *1 pilot lamp 20 of meter cluster 19 *2 diode 25 → excitation coil 21, The pressure reducing valve 17 continues to be prevented from being energized.

In addition, the self-holding relay 18 is activated when the air suspension 3LF, 3LR, 3RF, and 3RR are moved due to the movement of the vehicle.
The internal pressure fluctuates and pressure switch 12 turns ON-
Even if it is turned off repeatedly, the excitation coil 21 prevents the pressure reducing valve 17 from being energized.

Furthermore, when the vehicle transitions to steady driving after escaping from a muddy area, etc., the driver does not restore the shift of the vehicle body load on the wheel axles, that is, this device transfers the vehicle body load from the rear front axle 3 to the rear axle 4. If the amount moved by the operation is not returned, the strength and safety factor of the rear front wheel axle 3 will decrease.
Speed control 24 is speed sensor 23
The excitation coil 26 of the safety relay 22 is energized by the signal from the excitation coil 26, and the circuit which is a normally closed contact is interrupted by the excitation force of the excitation coil 26, and the energization to the solenoid valve 13 is cut off. −
B is energized to restore the wheel axle load to its original state.

Also, as shown in Figure 3, the operating mode of the speed control 24 is from 0 to 15km/h when the vehicle speed increases.
4 when the vehicle speed is decelerating from 15 km/h or higher.
It is set so that it does not turn on until the speed reaches Km/h.

Although air was used as the fluid in this embodiment, it is also possible to obtain substantially the same effect as in this embodiment by using air and liquid together and changing the air pressure in the air suspension by moving the liquid. .

According to this embodiment, by reducing the pressure of the air in the air suspension attached to some wheel axles of a vehicle having a plurality of wheel axles on which the vehicle body is suspended by air suspension, the air suspension is applied to other wheel axles. This has the effect of increasing the vehicle body load and increasing the driving force of the vehicle.

Further, since the throttle valve 27 is disposed next to the exhaust valve 17, it is possible to reduce the shock when reducing the pressure of the air in the air suspensions 4L and 4R.

(Effects of the invention) According to the invention, the pressure in the fluid suspension of the drive wheel shaft can be raised to and maintained at a predetermined maximum pressure, so that this predetermined maximum pressure can be increased, for example, to the maximum load specified by law. By setting the corresponding value, you can easily increase and maintain the load on the drive wheel axle up to the maximum load stipulated by law, ensuring that the maximum possible drive performance is obtained with simple operation and that the It has the advantage of easily improving running performance when traveling on roads.

Further, since a solenoid valve operated by a manually operated set switch and a pressure reducing valve controlled by a pressure reducing control means are used in combination, each valve can be controlled relatively easily.

[Brief explanation of the drawing]

FIG. 1 is a side view of the entire vehicle, FIG. 2 is an air and electric circuit diagram according to an embodiment of the present application, and FIG. 3 is a diagram showing the operating mode of the speed control. 2L, 2R, 3LF, 3LR, 3RF, 3RR, 4
L, 4R...Air suspension, 3...Rear front wheel axle, 4...Rear rear wheel axle, 11...Leveling valve, 12...Pressure switch, 13...Solenoid valve, 1
7...Reducing valve, 18...Self-holding relay, 22...
...Safety relay.

Claims (1)

[Scope of utility model registration request] A rear axle is constituted by a plurality of axles consisting of a driving wheel axle and a non-driving wheel axle, which suspend the vehicle body by means of fluid suspension, and the fluid suspension of the non-driving wheel axle is depressurized to reduce the pressure of the driving wheel axle. A vehicle configured to increase vehicle body support load, comprising a first port communicating with a fluid pressure source side, a second port communicating with a fluid suspension of the non-driving wheel axle, and a third port for fluid discharge. A solenoid valve that normally closes the third port and communicates the first port and the second port; a pressure reducing valve having a pressure reducing port for discharging fluid; a manually operated set switch that operates the solenoid valve to close the first port and communicate the second port with the third port; pressure detection means for detecting that the pressure within the fluid suspension of the wheel axle has reached a predetermined maximum pressure; and when the set switch is operated, the pressure reducing valve is operated to communicate the pressure reducing port with the third port. and pressure reduction control means for operating the pressure reduction valve to cut off communication between the third port and the pressure reduction port and maintain this state when the pressure detection means detects the predetermined maximum pressure. A vehicle body load adjustment device for a wheel axle, characterized in that: