JPH081930Y2 - Rear axle biaxial air suspension vehicle axle load adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an axle load adjusting device for a rear two-axis air suspension vehicle.

[Prior Art] Such a vehicle is known (for example, Japanese Utility Model Laid-Open No. 58-192108 by the present applicant).

In such a vehicle, when the vehicle body tilts during traveling on a snowy road, in order to prevent the rear front shaft, which is a drive shaft, from slipping,
A shaft load adjusting device is provided, and in the above case, the selector switch is used to switch the electromagnetic switching valve provided in the air circuit leading to the air spring of the rear rear axle (dead shaft), and the air of the air spring of the rear rear axle is switched. The weight of the rear and front axles is increased by letting it escape to the atmosphere.

However, in order to prevent the axle weight of the rear and front axles from becoming too large, the applicant of the present application has disclosed in Japanese Patent Application No. 61-146810 that the solenoid valve is an atmosphere release valve controlled by the pressure on the rear and front axles. We have proposed a device connected with.

Although the above proposal is effective, the atmosphere release valve is electrically controlled by the pressure switch provided in the air circuit leading to the air spring of the rear and front shafts. To support, multiple pressure switches are required. In addition, the pressure detected by a commercially available pressure switch is limited (for example, 7 kg / cm ² ), and special specifications are required. Further, the electric circuit requires a holding circuit, which complicates the control electric circuit and increases the cost.

Generally, an axle load adjusting device for a rear two-axis air suspension vehicle is known, and is disclosed in, for example, Japanese Utility Model Laid-Open No. 62-13705. However, such a known technique requires a relay device and a pressure reducing valve, has a complicated structure, and causes many failures.

Further, Japanese Utility Model Laid-Open No. 62-30905 discloses an air supply device for a vehicle having a pre-governor. However, such a known technique is provided to supply a large amount of high-pressure air, and the pressure detected by the pressure switch cannot be restricted.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to provide an axle load adjusting device for a rear two-axle air suspension vehicle, which has a simple structure without using a special specification product for a pressure switch and has few failures. It is in.

[Means for Solving the Problems] According to the present invention, a first air circuit connected from an air tank to an air spring of a drive shaft via a leveling valve and a dead air from the first air circuit via an electromagnetic switching valve. A second air circuit connected to the air spring of the shaft, a third air circuit branched from the electromagnetic switching valve and connected to the atmosphere opening valve, and an electric circuit for switching the electromagnetic switching valve with a changeover switch are provided. In the axle load adjusting device for a two-axle air suspension vehicle, the electromagnetic switching valve communicates the first air circuit with the second air circuit when not in operation and the second air circuit with the third air circuit when in operation. The atmosphere release valve closes the third air circuit when not in operation, opens the third air circuit to the atmosphere side when in operation, and connects to the first air circuit. Connect mechanical pressure governor Next, a pressure switch for closing the atmosphere release valve at a predetermined pressure or higher is provided in the relief passage of the mechanical pressure governor.

[Explanation of action and effect] Therefore, when the changeover switch is closed, the electromagnetic changeover valve communicates the second air circuit with the third air circuit, and the atmosphere release valve opens the third air circuit because the pressure switch is on. Since the air is released to the side, the air of the air spring of the dead shaft is released to the atmosphere, and as a result, the axial load of the rear front shaft increases. Since the electromagnetic switching valve closes the first air circuit, the air pressure in the first air circuit rises as the axle weight of the rear front shaft increases. When the pressure exceeds a predetermined value, the relief passage provided in the mechanical pressure governor for opening to the atmosphere (relief) is opened and the pressure switch is actuated to close the atmosphere opening valve. Therefore,
Since the increase in the axle weight of the rear and rear axles stops and the load is applied to the front and rear axles, the vehicle can travel on snowy roads.

As described above, the mechanical pressure governor controls the air pressure of the first air circuit within the control pressure range, so that the pressure switch provided in the relief passage is, as a matter of course, a pressure below a predetermined pressure. Since it works, a commercial product can be used.

 Moreover, the pressure of the pressure switch can be easily adjusted.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

In the figure, in the first air circuit L1 of the air tank 1,
Air springs 3FL, 3 of a pre-operation shaft (not shown) which is a drive shaft via leveling valves 2L, 2R for vehicle height adjustment according to known technology.
FR, 3RL and 3RR are connected in parallel. The first air circuit L1 on the side of the air springs 3FR and 3RR is the electromagnetic switching valve 4
The second air circuit L2 is connected to the air springs 5L and 5R of the rear rear axle (not shown) which is a dead axle via the.

The electromagnetic switching valve 4 is connected to the atmosphere release valve 6 by a third air circuit L3, and the first air circuit L1 is the fourth air circuit L4.
Is connected to the mechanical pressure governor 7, and a pressure switch 8 is provided in the relief passage of the governor 7. Then, the solenoid operated directional control valve 4 communicates the first air circuit L1 with the second air circuit L2 when it is not operated, and communicates the second air circuit L2 with the third air circuit L3 when it is operated. There is. Further, the atmosphere release valve 6 is a third air circuit when not operating.
L3 is closed, and the third air circuit L3 is opened to the atmosphere side when activated. Further, the governor 7 has a first air circuit in the control pressure range (for example, 7.0 kg / cm ² to 5.8 kg / cm ² ).
It is designed to control the air pressure of L1. Further, the pressure switch 8 is adapted to close at a predetermined pressure (for example, 5 kg / cm ² ).

On the other hand, a fuse 10, a normally closed changeover switch 11, and an electromagnetic changeover valve 4 are connected in series to the electric circuit 1 connected to the power source 9. An electric circuit branched from the electric circuit 1
A pressure switch 7 and an atmosphere release valve 6 are connected in series to l2, and a pilot lamp 12 arranged in a cluster meter (not shown) is connected to another branched electric circuit l3.

At the time of operation, the changeover switch 11 is closed when the rear-front shaft idles, for example, on a snowy road. Then, the pilot lamp 12 lights up, and the solenoid operated directional control valve 4 turns the second air circuit L2 to the third position.
Connect to circuit L3. On the other hand, since the mechanical pressure governor 7 is not relieved, no pressure is applied to the pressure switch 8 provided in the relief passage, and the predetermined pressure (for example,
Since it is less than 5 kg / cm ² ) it is closed. Therefore, the atmosphere release valve 6 opens the third air circuit L3 to the atmosphere side. Since the air of the air spring 5 is released, the rear rear shaft (dead shaft)
Decreases, and as a result, the axial weight of the front and rear shafts increases. Then
By boosting air pressure in the first air circuit L1 becomes equal to or larger than the set pressure of the mechanical pressure governor (for example, is set in a range of ^{7kg / cm 2 ~5.8kg / cm 2} ), a pressure relief passage is opened Since the switch 8 is opened and the atmosphere release valve 6 is closed, the lowering of the rear rear axle (dead axis) stops. The vehicle can easily travel due to the axle load acting on the rear front axle.

[Effect of the Invention] According to the present invention, the following excellent effects are achieved.

(I) By combining the mechanical pressure governor and the pressure switch, the electronic circuit for controlling the air bleeding of the dead shaft air spring can be simplified and the holding circuit can be eliminated.

(Ii) A commercially available pressure switch can be used and pressure adjustment is easy.

(Iii) Therefore, it is practically effective as a rear two-axis air suspension vehicle, and because it is compact, it is easy to install in a narrow space.

[Brief description of drawings]

FIG. 1 is an air and electric circuit diagram showing an embodiment of the present invention. 1 ... Air tank, 2 ... Leveling valve 3FL, 3FR, 3RL, 3RR, 5L, 5R ... Air spring, 4 ...
… Solenoid switching valve 6 …… Atmosphere release valve, 7 …… Mechanical pressure governor, 11…
… Changeover switch

Claims (1)

[Scope of utility model registration request] 1. A first air circuit connected from an air tank to a drive shaft air spring via a leveling valve, and a first air circuit connected from the first air circuit to a dead shaft air spring via an electromagnetic switching valve. A rear two-axis air suspension vehicle including a second air circuit, a third air circuit branched from the electromagnetic switching valve and connected to the atmosphere opening valve, and an electric circuit for switching the electromagnetic switching valve with a switching switch. In the axial load adjusting device, the electromagnetic switching valve communicates the first air circuit with the second air circuit when not in operation, and communicates the second air circuit with the third air circuit when in operation. The atmosphere release valve closes the third air circuit when not operating and opens the third air circuit to the atmosphere side when operating, and connects a mechanical pressure governor to the first air circuit, Mechanical pressure governor Axle load adjusting device biaxial air suspension vehicle after, characterized in that in the relief passage to a predetermined pressure or more is provided a pressure switch closing the air release valve.