JPS60143113A - Oil leakage detecting device for car height adjusting system - Google Patents

Abstract

PURPOSE:To accurately detect oil leakage by constituting a system in such a manner that, when abnormal lowering of both car height and working oil level in a tank is simultaneously detected, leakage in lower course of a hydraulic system that a leveling valve can also be detected. CONSTITUTION:When a pipe passage between, for example, a leveling valve 25 and an oil pressure source is damaged, causing oil leakage, contraflow of working oil staying upstream from the damaged point is prevented by a check valve not illustrated here. During this time, the oil is constantly drawn up, reducing the quantity of oil in the tank. When a shortage of oil is detected by a leveling sensor 40, the information about it is input into a controller 51. Then, a warning is issued, while power supply to the solenoid of the leveling valve 25 is disconnected in order to prevent oil leakage in the lower course. When oil leakage takes place between the leveling valve 25 and the car height adjusting equipment and also in the lower course than a oil leakage preventing valve, the oil level in the tank goes down, while the car height lowers. Then, the related outputs from the level sensor 40, car height sensors 42 and 43 are input into the controller 51 in order to issue an warning. With this contrivance, oil leakage at lower course than the oil leakage preventing valve can be detected and informed of.

Description

[Detailed Description of the Invention] In more detail, it can be used to prevent or warn against oil leakage caused by cracks or damage in the pipeline connecting the leveling valve and the vehicle height adjuster. This invention relates to an oil leak detection device for a vehicle height adjustment system.

A vehicle height adjustment device is a device that can adjust the vehicle body to an appropriate height depending on the size of the load and the number of passengers.This adjustment can improve ride comfort, handling, and driving stability of the vehicle. It is something that can be done. Therefore, in order to adjust the vehicle height level, the vehicle height adjustment device uses a hydraulic source such as a pump,
It has a hydraulic control system consisting of a leveling valve and piping, which adjusts it to an appropriate level depending on the vehicle height level.

However, if for some reason the pipe between the pump and the vehicle height adjuster, especially the pipe between the leveling valve and the vehicle height adjuster, is cracked or damaged, the hydraulic fluid pumped from the pump will In addition to being gradually discharged from the cracks to the ground outside the system, the hydraulic oil in the vehicle height adjuster also leaks out, gradually lowering the vehicle height, which becomes dangerous while the vehicle is in motion.

The present invention solves such conventional drawbacks, and aims to correctly detect oil leaks in the hydraulic control system of a vehicle height adjuster, particularly in the pipe line between the leveling valve and the vehicle height adjuster. Therefore, we provide an oil leak detection device for a vehicle height adjustment device that issues a warning based on this detection data to make it possible to stop the vehicle or close a valve in the hydraulic control system. do.

In order to achieve the above object, the present invention provides a vehicle equipped with a vehicle height adjuster that expands and contracts by receiving hydraulic fluid from a hydraulic source or discharging hydraulic fluid into a tank in response to switching control of a leveling valve. The height adjustment system includes a vehicle height sensor that detects an abnormal decrease in vehicle height, a level sensor that detects an abnormal decrease in the amount of hydraulic oil in the tank, and a level sensor that detects an abnormal decrease in the vehicle height and the amount of hydraulic oil. The oil leakage detection circuit is configured to include an oil leakage detection circuit that determines oil leakage in the hydraulic system after the leveling valve when simultaneously detected.

The present invention will be explained below based on the illustrated embodiments.

]- As shown in Figure 1, the oil leak detection device according to the present invention has a pressure oil supply circuit 2 that supplies a desired amount of hydraulic oil to one hydraulic operating mechanism 1, and a pressure oil supply circuit 2 that supplies a desired amount of hydraulic oil to one hydraulic operating mechanism 3. It has a hydraulic pressure supply circuit 4 that supplies a desired amount of hydraulic oil. In this embodiment, the hydraulic operating mechanism 3 is shown as a vehicle height adjustment device.

One of the hydraulic operating mechanisms 1 has an open center type valve, and in this embodiment is used as a power steering mechanism for a vehicle, and supplies a desired amount of hydraulic oil from the pressure oil supply circuit 2. When supplied, it is possible to operate, and it is also communicated via a circuit 5 so that the hydraulic oil after the operation is returned to the tank.

Note that when hydraulic oil is flowing in the pressure oil supply circuit 2, hydraulic oil is always supplied to one of the hydraulic operating mechanisms 1, but when the hydraulic operating mechanism 1 is not operated, Of course, it is returned to the tank via the circuit 5.

The other hydraulic operating mechanism 3 has a close center type valve, and in this embodiment is used as a vehicle height adjustment mechanism, and is connected to the pressure oil supply circuit 4 via a circuit 6. It is communicated with each other.

The other hydraulic operating mechanism 3 includes vehicle height adjusters 20 disposed on the left and right sides of the front and rear sides of the vehicle, respectively;
A circuit 22 that divides the hydraulic oil supplied to the vehicle height adjuster 20 via the circuit 6 to the rear side and front side of the vehicle.
A parallel circuit of a check valve 23 and a flow control valve 24 that are connected to each other, and a leveling valve 25 disposed in a circuit that communicates the check valve 23 with the vehicle regulator 20 on the front side and rear side of the vehicle.
Something that has the following.

It is.

Then, when hydraulic oil is supplied to the vehicle height adjuster 20,
The piston rod 20b that is slidably inserted into the cylinder 20 (Z) that constitutes the vehicle height adjuster 20 is raised, and the vehicle height of the vehicle is adjusted to be high. When the hydraulic oil is discharged from the vehicle height adjuster 20, the piston rod 20h in the cylinder 20α is lowered, and the height of the vehicle is adjusted to be lower.

Furthermore, when the hydraulic fluid that has passed through the check valve 23 is supplied to the vehicle height regulator 20 via the leveling valve 25, and when the hydraulic fluid is discharged from the vehicle height regulator 2o, the leveling valve 25 is switched to the position 25d. , it is not necessary to supply hydraulic oil to the vehicle height adjuster 20, and
Of course, when there is no need to discharge the hydraulic fluid from the vehicle height adjuster 20, the leveling valve 25 is switched to the position 25h. Although not shown, each switching operation of the leveling valve 25 is performed by energizing the solenoid 25C by human power, such as a vehicle height sensor appropriately installed in the vehicle height adjuster 20, etc. be.

In addition, 26 is an oil leak prevention valve connected between the leveling valve 25 and each vehicle height adjuster 20 on the front side and rear side of the vehicle, and as shown in Figure 2 (a), the oil leak prevention valve 26
A spool 26C supported by a spring 26h is housed in 6.2, and one oil chamber 26d partitioned by the spool 26C is provided with a return passage leading to the return circuit 38, and the peripheral wall and end wall of the other oil chamber 26g are Passages are provided that communicate with the vehicle height adjuster 20 and the leveling valve 25, respectively. According to this, when an oil leak occurs due to damage to the pipe line (circuit) between the vehicle height adjuster 20 and the leveling valve 25, the pressure inside the oil chamber 26g decreases, and the spool 26C The passage is closed, thereby preventing oil from flowing out from the vehicle height adjuster 20. Note that the hydraulic oil in the oil chamber 26d leaks from the outer periphery of the spool 26C and is returned to the tank via the return circuit 38.

On the other hand, the oil leakage prevention valve 26 shown in Figure 2 (A)
Even if a poppet valve 26C as shown in Fig. 2.2 (B) is used instead of the spool 26C inside, the same effect as in Fig. 2 (A) can be obtained, but in particular, using the poppet valve 260 The effect of preventing oil leaks will be even greater.

Further, an accumulator 2 is connected between the oil leak prevention valve 26 and the vehicle height adjuster 20 via a damping force generating valve 27.
8 is provided with a solenoid valve 29.

The pressure oil supply circuit 2 has a hydraulic source 30 consisting of a pump, which discharges hydraulic oil from a tank 31 to one of the hydraulic operating mechanisms 1, and the pressure oil supply circuit 4 has a hydraulic source 32 consisting of a pump. The hydraulic oil from the tank 31 is discharged to the other hydraulic operating mechanism 3. In this embodiment, the pump as the hydraulic power source 30, 32 is provided to be driven by the engine of the vehicle.

33 and 34 are flow control valves connected to the pressure oil supply circuits 2 and 4, respectively, to secure the amount of oil required for each operation of the power steering mechanism as the hydraulic operation mechanism 1 and the vehicle height adjuster 20, and to prevent excess oil. The flow is hydraulic [30,
32 downstream to the pressure oil supply circuit 2 for recycling, but it can also be returned directly to the tank 31 if necessary.

In addition, relief valves 35 and 36 are provided in the circuit between the flow control valves 33 and 34 and the tank 31, respectively, and are activated when the hydraulic pressure supplied to the hydraulic operating mechanism 1.3 exceeds a set pressure. For example, when the viscosity of the hydraulic oil is high such as in a cold region, or when the flow resistance of the hydraulic oil in the pipe becomes high due to a failure of the hydraulic operating mechanisms 1 and 3. limit the supply of hydraulic fluid.

37 is an unload valve connected in the middle of the circuit 6 connecting the flow control valve 34 and the check valve 22 and between the tank 310, and is in a cutoff state when supplying hydraulic oil to the hydraulic operating mechanism 3, and is in a disconnected state after being in a communication state. The hydraulic oil from the flow control valve 34 is transferred to the tank 31
will be returned to. In addition, this unload valve 3
7 is controlled based on the output of a vehicle height sensor appropriately installed in the vehicle height adjuster 20.

In the vehicle height adjustment system having the hydraulic operating mechanism 1 having such a configuration, the hydraulic operating mechanism 1 receives hydraulic pressure from the hydraulic source 3o, and supplies appropriate hydraulic pressure to various parts of the hydraulic operating mechanism 1, such as a power steering system, to turn the steering wheel. Ask for help J:8
At the same time, the vehicle height adjuster 20 as the hydraulic operating mechanism 3 receives hydraulic pressure from the hydraulic source 32 and operates to adjust the vehicle height while responding to the leveling valve 25 and the unloading valve 37.゜On the other hand, the tank 31 is provided with a level sensor 40, 111, which is the level sensor 40 installed in the tank 31.
Detects when the hydraulic fluid in the tank has decreased below a predetermined level.

Further, vehicle height sensors 42 and 43 are respectively attached to the center portions of the stabilizers 41 provided at the front and rear of the vehicle. Note that each of these sensors 42,
43 can be provided for each wheel, and the stabilizer 4
It is also possible to install the piston rod 20b at a suitable location other than 1, for example, in the cylinder 20a, so as to directly detect the amount of vertical movement of the piston rod 20b.

Figure 3 of Liu is a circuit block diagram of the oil leak detector of the present invention. In the figure, 40 is a level sensor for the hydraulic oil in the tank 31, and 42.43 is a vehicle height sensor, and the outputs of these sensors 40, 42, and 43 are respectively A.
input to ND gates 44 and 45, and A of l'l et al.
The outputs of the ND gates 4, 4, and 45 are input to an OR gate 46. Further, the output terminal 47 of the level sensor 40 is an output terminal that outputs a leak detection signal of the hydraulic oil in the system, and the output terminal 48 is an output terminal that outputs a leak detection signal of the hydraulic oil after the leveling valve 25.

Note that 49.50 is a warning lamp attached to the controller 51 connected to each output terminal to indicate an oil leak in each part of the system, and is installed, for example, on the dash board of a vehicle.

Next, the oil leak detection operation of the above device and circuit will be explained.

Now, in the pressure oil supply circuit 4 or circuit 6 that connects the hydraulic power source 32 and the leveling valve 25, for example, if the pipe L is damaged at the X point of the circuit 6 and an oil leak occurs, the leveling valve 25 The hydraulic fluid on the more upstream side is temporarily prevented from flowing back by the check valve 23, and then gradually leaks out through the flow control valve 24. However, during this time, the hydraulic power source 32 continues to pump up the hydraulic fluid in the tank 31. The amount of hydraulic oil in 31 has decreased significantly. Therefore, the level sensor 40 detects a lack of hydraulic oil at the set level of the hydraulic oil, and the controller 51
The sensor output is distorted. The controller 51 flashes the alarm lamp 49 based on this sensor output, indicating that an oil leak accident has occurred in the piping upstream of the leveling valve 25, and prompting the driver to take emergency measures.

Further, based on the sensor output of the level sensor 40, the controller 51 cuts off the power to the solenoid 25C of the leveling valve 25, thereby preventing leakage of hydraulic oil downstream of the leveling valve 25.

Next, in the circuit that connects the leveling valve 25 and the vehicle height adjuster 20, if a damage accident occurs on the piping at point Y downstream of the oil leak prevention valve 26 and oil leaks from there, the oil Hydraulic oil continues to flow into the leak prevention valve 26 through the leveling valve 25 and leaks in large quantities from point Y, so the amount of hydraulic oil in the tank 31 gradually decreases. On the other hand, the hydraulic oil in the cylinder 20a of the vehicle height adjuster 20 leaks from point Y due to the lowering of the piston rod 205 due to the weight of the vehicle.

Due to these two oil leakage operations, the level sensor 40 of the tank 31 detects a shortage of hydraulic oil, and converts the sensor output into A.
At the same time as the ND gate 44 is manually operated, the vehicle height sensor 42 detects that the vehicle height has fallen below a set level, and the sensor output is manually input to the AND gate 44 . Therefore, an alarm signal is obtained at the AND gate 44 and the OR gate 46, and the alarm signal is sent to the controller 5 through the output terminal 48.
Based on the alarm signal 2, which was manually input by the controller 51, the controller 51 blinks the alarm lamp 50, indicating that an oil leak accident has occurred downstream of the leveling valve 25 and further downstream of the oil leak prevention valve 26. is displayed.

Note that if an oil leakage accident occurs between the leveling valve 25 and the oil leakage prevention valve 26, the oil leakage prevention valve 26 will prevent the oil leakage downstream from this, and the oil leakage prevention valve 26 will prevent the oil leakage from occurring between the oil leakage prevention valve 26 and the oil leakage prevention valve 26. Oil leakage can also be detected by the level sensor 40 of the tank 31 and controlled by the controller 51 to close the leveling valve 25.

As described above, according to the present invention, an oil leak accident in the conduit connecting the leveling valve and the vehicle height adjuster can be easily and reliably detected from the level of the hydraulic oil in the tank 31 and the vehicle height level. Based on this detection output, it is possible to issue an alarm or prompt for specified recovery work, and it is also possible to prevent hydraulic oil from flowing out by closing the leveling valve. reactor.

[Brief explanation of the drawing]

Figure 1 is a hydraulic control circuit diagram showing the vehicle height adjustment system according to the present invention, Figures 2 (A) and (B) are cross-sectional views of the oil leak prevention valve, and Figure 3 is a diagram of the oil leak prevention device of the present invention. It is a block connection diagram. 20...Vehicle height adjuster, 25.Φ.Leveling valve,
30-1 hydraulic power source, 31.1 tank, 40 level sensor, 42 vehicle height sensor. Representative Patent Attorney Izumi Ohno

Claims (1)

[Claims] (111/Vehicle height adjustment equipped with a vehicle height adjuster that expands and contracts by receiving hydraulic fluid from a hydraulic source or discharging hydraulic fluid into a tank in response to switching control of a Hering valve. In the system, a vehicle height sensor detects an abnormal decrease in vehicle height, a level sensor detects an abnormal decrease in the amount of hydraulic oil in the tank, and simultaneously detects an abnormal decrease in vehicle height and an abnormal decrease in the amount of hydraulic oil. An oil leak detection device for a vehicle height adjustment system, characterized in that the oil leak detection circuit is equipped with an oil leak detection circuit that determines an oil leak in the hydraulic system after the Heringhalb. (2) The oil leak detection circuit is a level An oil leak detection device for a vehicle height adjustment system according to claim 1, which is an AND gate in which the sensor output and the vehicle height sensor output are performed by two people.