JPS63149262A - Vehicle hydraulic system - Google Patents

Abstract

PURPOSE:To make it possible to ensure the operation of a main accessory in order to enhance the safety of a vehicle hydraulic system in which more than two accessories are driven by a common pump, by changing over a control valve in accordance with abrupt leakage of hydraulic oil due to a failure or the like on the subaccessory side. CONSTITUTION:Oil discharged from a pump 100 driven by an engine flow through a control valve 200 into an inlet side hydraulic circuit 301 which drives a hydraulic motor 300 for rotating a fan 30. During this phase, when steering operation is made, a steering priority valve 321 opens a communication passage 32 so that a substantial part of the discharged oil bypasses the motor 300 and flows into an outlet side hydraulic circuit 305 from which the oil is fed into a power cylinder 400. Meanwhile, when the hydraulic motor 300 malfunctions so that the pressure of oil in the hydraulic circuits 301, 305 is lowered, a selector valve element 204 is displaced until it abuts against a stop 218 in accordance with the pressure differential between first and second pressure chambers 213, 214, and therefore, all amount of oil is fed into the power cylinder 400 side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vehicle hydraulic system, and relates to a hydraulic system for a vehicle, in which, for example, a power steering cylinder and a radiator fan drive motor are powered by oil discharged from one hydraulic pump. It is effective for use in operating systems.

[Prior art and its problems]

Conventionally, power cylinders for vehicle power steering have been operated by receiving hydraulic pressure from a dedicated hydraulic pump. It has also been proposed to receive hydraulic pressure from the hydraulic pump for driving the power cylinder to drive other auxiliary equipment from the power cylinder, such as a hydraulic motor for driving the engine radiator cooling fan.

Here, the power cylinder for driving the power steering is an extremely important auxiliary device for the safety of the vehicle, and not only the hydraulic pump but also the power cylinder and the hydraulic circuit are arranged at a position where safety can be ensured. However, if the oil from the hydraulic pump is to simultaneously drive the radiator fan, the oil from the hydraulic pump must be extended to the mounting position of the radiator via an oil passage. Since the radiator is usually mounted at the very front of the vehicle, it poses a safety problem compared to the above-mentioned power cylinder and the like. Furthermore, the hydraulic motor
For example, if the fan receives some kind of external force and becomes malfunctioning, there is a risk that the fan will become inoperable. Here, if the radiator fan, hydraulic motor, or the like is damaged, there is a risk that a large amount of operating oil may flow out from the oil passage at once.

If a large amount of hydraulic oil leaks out in this way, there is a fear that the power cylinder for driving the power steering will not operate smoothly, which poses a safety problem for the vehicle.

[Problem to be solved by the invention]

The present invention has been devised in view of the above-mentioned points, and in a vehicle hydraulic system in which two or more auxiliary machines are driven by one shared hydraulic pump, when a failure occurs in a secondary auxiliary machine, The purpose of this is to ensure that the main auxiliary equipment is supplied with working oil.

[Configuration and operation]

In order to achieve the above object, in the vehicle hydraulic system of the present invention, a control valve is disposed between the main auxiliary equipment and the auxiliary equipment, and this control valve is used to prevent sudden leakage of working fluid from the auxiliary equipment side. The oil passages are switched based on the oil pressure. In other words, if the pressure difference before and after the control valve increases beyond a predetermined value,
Make sure that the oil from the hydraulic pump flows only to the main auxiliary equipment side. In other words, the oil from the hydraulic pump is controlled to flow to the auxiliary auxiliary equipment only when a certain amount or less of oil is maintained to be circulated on the auxiliary auxiliary equipment side.

〔Effect of the invention〕

By employing the above configuration, in the system of the present invention, it is possible to simultaneously drive an auxiliary machine that is important for vehicle safety and an auxiliary machine that is not important for vehicle safety using one hydraulic pump. Therefore, in vehicles equipped with many auxiliary machines,
This has the excellent effect of easing restrictions on its mounting.

〔Example〕

In FIG. 1, reference numeral 100 denotes a hydraulic pump, which operates in response to the rotational driving force of an automobile engine (not shown). This hydraulic pump 100 sucks working oil in an oil reservoir 101 through a suction passage 102 .

Then, it is discharged to the discharge passage 103 side.

A relief valve 104 is disposed on the outlet side of the hydraulic pump 100, and this relief valve allows the hydraulic pump 100 to
The discharge pressure of the oil discharged is always controlled to be below a certain pressure. That is, since the hydraulic pump 100 operates in response to the rotational driving force of the automobile engine,
The discharge amount of the hydraulic pump 100 also varies greatly depending on the engine rotation speed. The relief valve 104 suppresses changes in the discharge pressure due to variations in the discharge amount.

The discharge passage 103 is connected to the fan drive via the control valve 200.
It communicates with the hydraulic circuit 301 for the motor 300.

The hydraulic motor 300 drives a fan 302 that guides cooling air to the engine radiator 301. Note that a fan shroud 303 is disposed between the fan 302 and the radiator 301, and rectifies the cooling air generated by the fan 302. The hydraulic motor 300 rotates a shaft 304 under the pressure of working oil.

Further, the motor 300 communicates with an outlet side hydraulic circuit 305,
This outlet side hydraulic circuit 305 communicates via the control valve 200 with an inlet side hydraulic circuit 401 of a power cylinder 400 that drives the power steering.

In addition, in this example, the hydraulic motor 300 becomes a sub-auxiliary machine, and the power cylinder 400 becomes a main auxiliary machine.

Furthermore, a flow rate control passage 310 and a power steering priority passage 320 are formed in the hydraulic circuits 301 and 305 of the hydraulic motor 300, bypassing the hydraulic motor. A flow rate control valve 311 is disposed in the middle of the flow rate control passage 310, and the flow rate control valve 311 controls the flow rate control passage 31.
1, the flow rate of hydraulic oil through it is controlled.

Here, if a large amount of working oil flows into the flow rate control passage 310, the amount of working oil supplied to the hydraulic motor 300 will be small. Conversely, if a large flow resistance is provided on the flow control passage 310 side and the flow rate of the working oil flowing through the flow control passage 310 becomes small, the hydraulic motor 30
0 will be supplied with a large amount of working oil. If a large amount of hydraulic oil is supplied to the hydraulic motor 300, the hydraulic motor will rotate at high speed. Conversely, if the flow rate of the working oil supplied to the hydraulic motor 300 becomes smaller, the hydraulic motor 30
The rotation speed at 0 becomes small. Therefore, this flow control valve 31
1, it is possible to control the rotation speed of the motor 300 by controlling the flow rate of the working oil flowing in the flow rate control passage 310. Therefore, the flow rate control valve 311 variably controls the passage opening cross-sectional area from the flow rate control passage 310 in accordance with the cooling capacity required from the radiator 301 side.

Further, the power steering priority passage 320 is also arranged to bypass the hydraulic motor 300, similar to the above-described flow control passage 310. A power steering priority valve 321 is disposed in the middle of this power steering priority passage 320. This power steering priority valve normally closes passage 320. However, when the power cylinder 400 for power steering starts operating, the passage 320 is opened due to an increase in back pressure.

The hydraulic motor 300 for cooling the radiator 301 is used frequently, whereas the power cylinder 400 for power steering needs to operate only when the occupant performs a steering operation at low speed.

That is, power cylinder 400 is used less frequently.

However, when an occupant performs a steering operation, it is necessary to reliably supply operating oil to the power cylinder. That is, when the power cylinder operates, oil from the hydraulic pump 100 needs to be supplied preferentially to the power cylinder. Therefore, under such conditions, power steering priority valve 321 opens passage 320. By opening the passage 320, the hydraulic oil in the inlet hydraulic circuit 301 bypasses the motor 300 and flows to the outlet hydraulic circuit 305. That is,
The driving force of the working oil is supplied to the power cylinder 400 side without being consumed by the motor 300.

Note that a constant flow valve 410 is disposed in the inlet side hydraulic circuit 401 of the power cylinder. This constant flow valve 410 keeps the flow rate flowing into the power cylinder 400 constant. That is, the flow rate in the inlet side hydraulic circuit 401 is
Depending on the capacity of the hydraulic motor 300, the power cylinder 40
The specified flow rate of 0 may be exceeded. Here, if the flow rate in the hydraulic circuit 401 is larger than the specified flow rate (if there is a difference), the control state of the power cylinder will not be constant, and the occupant will not be able to perform a good steering operation.

Therefore, a constant flow valve 410 is provided on the inlet side of the power cylinder 400 to ensure smooth operation. Further, an outlet side hydraulic circuit 402 of the power cylinder 400 is provided, and this hydraulic circuit 400 has an oil reservoir 1.
Connects to 01.

Next, the structure of the control valve 200 will be explained. Figures 2 and 3
As shown in the figure, this control valve switches the discharge passage 103 into communication with either the inlet hydraulic circuit 301 on the motor 300 side or the inlet side circuit 401 on the power cylinder 400 side. In addition, in the drawing, the inlet on the discharge passage 103 side is indicated by A, the opening communicating with the inlet side hydraulic circuit 301 of the motor 300 example is indicated by B, the opening communicating with the outlet side hydraulic circuit 305 is indicated by C, and, An opening communicating with the inlet hydraulic circuit 401 on the power cylinder 400 side is indicated by D. Second
In the figure, the hydraulic oil from the discharge passage 103 is supplied to the hydraulic motor 30.
FIG. 3 shows a state in which hydraulic oil is not supplied to the hydraulic motor 300 side.

That is, as shown in FIG. 4, this control valve 200 has a communication passage 207 that connects openings A, B, C, and D, and openings C and D, and a communication passage that connects the housing 202 of the control valve 200.
form within. A cylindrical valve space 203 is formed within the control valve housing 202, and a switching valve body 204 is slidably disposed within this valve space. Note that the switching valve body has a stepped cylindrical shape, and its large diameters 205, 206, 207, and 208 are connected to the valve space 203.
The valve space 203 is in sliding contact with the valve space 203, and oil tightness is maintained between the valve space 203 and the valve space 203. In addition, the small diameter portions 209, 210, 21 of the switching valve body 204
1 each form a switching passage. Second small diameter section 210
A passage chamber 212 formed by the first large diameter portion 205 and a pressure chamber 213 formed by the valve space 203 are communicated with each other by a pressure guiding passage 214 . Also, the second
A side surface of the large diameter portion 206 and a pressure chamber 215 formed by the fourth large diameter portion 208 and the valve space 203 are communicated through a pressure guiding passage 216 . Further, a spring 217 is disposed within the pressure chamber 215, and the spring 217 urges the switching valve body 204 toward the pressure chamber 213. Furthermore, a stopper 218 is provided in the pressure chamber 215.
is disposed, and this stopper 218 restricts displacement of the switching valve body 2Q4 toward the pressure chamber 215 side.

Further, a switching valve body 20 is provided between the passage chamber 212 and the opening B.
4 and the control valve housing 202 is present. Similarly, in the switching state (FIG. 3), a throttling mechanism formed by the switching valve body 204 and the control valve housing 202 exists between the passage chamber 212 and the opening.

The control valve 200 of this example is automatically switched depending on the pressure state in which the control valve 200 is placed by pressure guiding passages 214 and 216 formed in the switching valve body 204.

Next, the operation of the above hydraulic system will be explained.

The hydraulic pump 100 receives the rotational driving force of the automobile engine and discharges working oil. The discharge pressure of this working oil is maintained at a constant value by the relief valve 104. In the steady operating state of the automobile, the hydraulic oil flows through the control valve 2.
00, and flows to the inlet side hydraulic circuit 301 side. In this state, the motor 300 is rotationally driven by the oil pressure in the inlet side hydraulic circuit 301. In the steady state, the flow rate passing through the throttle formed between the discharge passage 103 and the inlet side passage 301 is also less than the specified value, and therefore the differential pressure before and after the restriction is also less than the specified value.

As shown in FIG. 4, the pressure on the discharge passage 103 side is transferred from the passage chamber 212 to the first pressure chamber 213 through the pressure guiding passage 214.
guided by. Moreover, the pressure inside the inlet side hydraulic circuit 301 is
It is guided into the second pressure chamber 215 via the pressure guiding passage 216. Therefore, the pressure difference between the two ends of the switching valve body 204 is less than or equal to the specified value, and the first pressure chamber 213 is guided by the pressure guiding passage 214 by the biasing force of the spring 217.
The pressure becomes overwhelming. Therefore, under the urging force of the spring 217, the switching valve body 204 is displaced toward the first pressure chamber 213. According to this displacement, passage chamber 212
This causes the discharge passage 103 and the inlet hydraulic circuit 301 to communicate with each other. Further, the outlet side hydraulic circuit 300 of the hydraulic motor 300 and the power cylinder 4 are connected via the communication passage 207.
This will communicate with the inlet side hydraulic circuit 401 of 00.

Therefore, in this state, the working oil from the hydraulic pump 100 is well supplied to the motor 300, and the motor 300
rotates the fan 302.

In this state, the rotational force of the fan 302 is controlled by the flow rate control valve 311 as described above.

Further, in such a state, when it becomes necessary to operate the power steering, the power steering priority valve 321 opens the passage 320.

Since the flow resistance of the passage 320 is extremely small compared to the hydraulic motor 300, most of the working oil in the inlet hydraulic circuit 301 bypasses the motor 300 and flows to the outlet hydraulic circuit 305. By doing this, the rotation of the motor 300 is stopped and sufficient working oil is supplied to the power cylinder 400.

By the way, since the radiator 301 is located at the very front of the car, if the car causes a collision,
There is also a risk that the radiator 301 and hydraulic motor 300 may be damaged. Furthermore, there is a risk that foreign matter may get caught in the fan 302 or the hydraulic motor 300, causing malfunction of the hydraulic motor 300. In such a case, if the inlet side hydraulic circuit 301 or the outlet side hydraulic circuit 305 is damaged, the pressure in the hydraulic circuits 301, 305 will drop rapidly even while the vehicle is running. However, even in such a state, it is necessary for the safety of the vehicle that sufficient hydraulic oil be supplied to the steering power cylinder 400. Therefore, in such a case, the control valve 200 is connected to the hydraulic circuit 301 on the hydraulic motor 300 side.
, 305.

As described above, the pressure in the inlet hydraulic circuit 301 on the side of the abnormal hydraulic motor 3°O decreases rapidly, and the flow rate increases rapidly. Due to the increase in flow rate, the pressure difference generated before and after the constriction formed between the passage chamber 212 and the opening B increases, and the high pressure on the discharge passage side is transmitted to the first pressure chamber via the pressure guiding passage 216. be done. On the other hand, the inlet side hydraulic circuit 30
The low pressure of 1 is transmitted to the second pressure chamber 12 via the pressure passage 216.
5. Therefore, a pressure difference occurs between the first pressure chamber 213 and the second pressure chamber 214, and based on this pressure difference,
The switching valve body 204 remains in the second position until it comes into contact with the stopper 218.
It is displaced to the pressure chamber 215 side.

The state after this displacement is as shown in FIG.
Connects to 1. Inlet side hydraulic circuit 3 on the hydraulic motor 300 side
01 is closed by the second large diameter portion 206. Similarly, the outlet side hydraulic circuit 305 on the side of the hydraulic motor 300 also has a first
It is closed by the large diameter section 205. Therefore, damage to the hydraulic motor 300 side will not have any adverse effect on the power cylinder 400. In particular, as shown in FIG. 3, after the switching valve body 204 is displaced, the third large diameter portion 207
A fluid restriction is formed between the opening B and the opening B.

The action of this throttle prevents the switching valve body from automatically returning again.

Note that, although the above-mentioned example is a desirable response of the present invention, the present invention has various other responses. FIG. 5 shows another shape of the control valve 200. This figure 5 illustration system 211
The valve has a pilot valve 250 housed in a switching valve body 200. The pilot valve 250 has a spring 251
The pressure guiding passage 214 is normally opened by receiving a predetermined urging force from the opening. Therefore, the differential pressure between the pressure on the discharge passage 1°3 side received via the first passage 253 and the pressure on the inlet side hydraulic circuit 301 received via the second passage 254 is
If the biasing force is smaller than the biasing force of the pilot valve 250, the pilot valve 250
Passages 253 and 254 are closed.

Therefore, the pressure inside the communication passage 212 is reduced to the first pressure chamber 213.
is not transmitted. Therefore, the switching valve body 204 is displaced toward the first pressure chamber 213 under the biasing force of the spring 217.

However, if the pressure in the inlet side hydraulic circuit 301 of the hydraulic motor 300 suddenly decreases,
Pilot valve 250 opens pressure passage 214 and closes second passage 254 . As a result, the pressure within the passage chamber 212 is supplied from the first passage 253 to the pressure chamber 213 via the pressure guiding passage 214. This high pressure causes the switching valve body 204 to
It is displaced to the pressure chamber 215 side. This displacement causes switching of the control valve as shown in FIG.

Furthermore, in the above example, a power cylinder for driving power steering was used as the main auxiliary machine, and a hydraulic motor 300 was used as the auxiliary machine, but the present invention can also be used for other auxiliary machines installed in automobiles. Of course it is possible. For example, as shown in FIG. 6, a brake cylinder 500 may be used as the main auxiliary device, and a hydraulic motor 300 may be used as the auxiliary device to drive an automobile alternator or a refrigerant compressor 501 of an automobile air conditioner.

Furthermore, as shown in FIG. 7, three auxiliary machines may be arranged in series. In this case, a second control valve 280 is arranged in addition to the first control well 200. That is, the first control well 200 and the second control well 280 are arranged in series in this order depending on the safety importance of the auxiliary equipment. For safety reasons, auxiliary equipment is also important, such as the brake cylinder 500 and the hydraulic pump 10.
0 closest to power steering, then power steering 40
0 is placed, and other auxiliary equipment, such as a hydraulic morph 300 for driving the radiator fan 302, is placed.

Furthermore, as shown in FIG.
It may also be possible to notify abnormal conditions such as. In the example shown in FIG. 8, the displacement of the switching valve body 204 is determined by the position switch 60.
Detected by 0. Then, based on the signal from the position switch 600, the emergency light 601 is turned on or an emergency buzzer is sounded. Note that 602 is an in-vehicle battery.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an example of the hydraulic system of the present invention;
3 and 3 are sectional views showing the operating state of the control valve 200 shown in FIG. 1, FIG. 4 is a sectional view showing the internal structure of the control valve 200 shown in FIG. 1, and FIG. 5 is another example related to the present invention. 5 and 6 are circuit diagrams showing other hydraulic circuits related to the present invention, and FIG. 8 is a sectional view showing another example related to the present invention. 100...Hydraulic pump, 103...Discharge passage, 20
0...Control valve, 300...Hydraulic motor, 301...
- Inlet side hydraulic circuit, 305... Outlet side hydraulic circuit, 40
0...Power cylinder, 401...Inlet side hydraulic circuit, 402...Outlet side hydraulic circuit.

Claims (4)

[Claims] (1) A hydraulic pump that takes in and discharges working oil, a main auxiliary machine that operates in response to the pressure of the working oil discharged from this hydraulic pump, and a main auxiliary machine that is arranged in series with this main auxiliary machine and that operates from the hydraulic pump. at least one auxiliary auxiliary machine that operates in response to hydraulic pressure of oil; the auxiliary auxiliary machine is arranged between the auxiliary auxiliary machine and the main auxiliary machine, and controls the supply of oil from the hydraulic pump to the auxiliary auxiliary machine; a control valve, the control valve has a throttle mechanism in the main body, and the pressure difference increases to a predetermined pressure difference or more in response to a pressure difference between the pressure on the auxiliary auxiliary equipment side and the pressure from the hydraulic pump side. In this case, the oil from the hydraulic pump is controlled to flow only to the main auxiliary machine side, and when the pressure difference is equal to or less than a predetermined pressure difference, the oil from the hydraulic pump is controlled to flow also to the auxiliary machine side. A vehicle hydraulic system featuring: (2) The hydraulic pump is equipped with a constant relief valve mechanism, and the pressure of the oil discharged from the hydraulic pump is maintained at a constant value or less. Vehicle hydraulic system. (3) The vehicle hydraulic system according to claim 1 or 2, wherein the main auxiliary machine is a power cylinder for driving power steering of an automobile. (4) The vehicle hydraulic system according to any one of claims 1 to 3, wherein the sub-auxiliary equipment is a hydraulic motor that drives a fan.