JP2661436B2 - Cooling fan drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling fan drive for driving a cooling fan of a radiator by a hydraulic motor.

[0002]

2. Description of the Related Art In recent years, as a radiator cooling fan for an FF vehicle with an engine mounted sideways, a variable-speed variable-speed hydraulic drive fan using a hydraulic motor has been adopted instead of the conventional electric fan with a constant speed. As such a hydraulic cooling fan driving device, for example, as described in Japanese Utility Model Application Laid-Open No. 61-138831, a hydraulic pump for driving a cooling fan and a hydraulic pump for power steering are coaxially arranged. 2. Description of the Related Art There is known an arrangement in which an engine is driven by an engine in a series arrangement. In this type of cooling fan driving device, the discharge capacity of the cooling fan driving hydraulic pump is determined so that a sufficient fan speed can be obtained even during idling when the cooling effect of the traveling wind cannot be expected, while the hydraulic pressure for power steering is determined. The discharge capacity of the pump is set such that a sufficient assist force can be obtained even when the maximum steering angle is given at the time of stationary operation such as garage parking where the load applied to the steering device increases most.

[0003]

By the way, in the cooling fan drive described above, the discharge capacity of each hydraulic pump is set on the basis of an idling or a very low speed such as a garage, so that the pump rotation during the normal running is performed. As the number increases, the discharge flow rate becomes excessive. Therefore, measures must be taken to release the excess pressure oil to the tank, and the pressure oil that has been pressurized is simply discarded, thus wasting the hydraulic pump driving energy. By the way, since the rotation speed of the cooling fan is at most about twice the idling time, if the rotation speed of the cooling fan drive motor exceeds twice the idling time, all subsequent increases in the discharge flow rate are returned to the tank. . Also, even with power steering,
During running, there is no sudden large turning, so the required discharge flow rate is significantly less than when entering the garage, etc.
During traveling, a considerable amount of oil is returned to the tank.

On the other hand, in order to reduce the waste of the driving energy of the hydraulic pump, the discharge capacity of the hydraulic pump may be reduced. However, in this case, the discharge flow rate of the hydraulic pump is insufficient at the time of idling or garage entry, which leads to overheating and insufficient assist force.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling fan drive device capable of supplying a sufficient amount of pressure oil to a cooling fan drive motor and a power steering actuator while reducing wasted drive energy of a hydraulic pump. is there.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIG. 1 showing an embodiment. In the cooling fan drive device of the present invention, a first oil supply system for supplying pressure oil to a cooling fan drive hydraulic motor 5 of a radiator is provided. A hydraulic pump 2, a second hydraulic pump 3 for supplying pressure oil to the power steering actuator 6, and a pressure detecting means 9 for detecting that the driving pressure of the power steering actuator 6 has reached a predetermined value.
When the pressure detecting means 9 detects the predetermined value, the pressure oil replenishing means 11 () replenishes at least a part of the pressure oil discharged from the first hydraulic pump 2 to the power steering actuator 6. The above object is achieved by providing (4, 8, 10).

[0007]

When the driving pressure of the power steering actuator 6 rises and exceeds a predetermined value by turning the steering wheel rapidly and at a large steering angle at the time of extremely low speed and high load such as when putting in a garage, the pressure detecting means 9 When this is detected, the pressure oil replenishing means 11 operates to supply at least a part of the pressure oil discharged from the first hydraulic pump 2 for the cooling fan to the power steering actuator 6. Therefore, the required discharge flow rate of the second hydraulic pump 3 for power steering when entering the garage or the like is sufficient even if it is smaller than the supply of hydraulic oil from the first hydraulic pump 2 for the cooling fan. The drive energy can be reduced by using the second hydraulic pump 3 having a discharge capacity smaller than that of the conventional hydraulic pump.

[0008] In the means and means for solving the above-mentioned problems which explain the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. It is not limited to.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a cooling fan drive device according to the present embodiment includes a first hydraulic pump 2 connected to an engine 1 of a vehicle via power transmission means such as a fan belt, and a first hydraulic pump 2. And a second hydraulic pump 3 that is coaxially arranged in series and is rotationally driven in the same direction and at the same speed as the first hydraulic pump 2. The first hydraulic pump 2
The hydraulic oil discharged from the second hydraulic pump 3 is guided to the cooling fan drive motor 5 via the electromagnetic control valve 4, while the hydraulic oil discharged from the second hydraulic pump 3 is guided to the power steering actuator 6. I have. The oil discharged from the cooling fan drive motor 5 and the power steering actuator 6 is returned to the tank 7.

The electromagnetic control valve 4 includes a solenoid coil 4
A known position in which the position of a built-in valve body is switched by the excitation of a, a normal position (a position) for guiding the entire amount of pressure oil discharged from the first hydraulic pump 2 to the cooling fan drive motor 5, and a cooling fan drive The supply amount of pressure oil to the motor 5 is reduced, and the remaining pressure oil can be switched between a supply position (b position) where the remaining pressure oil is guided to the power steering actuator 6 via the supply path 8.

A pressure switch (pressure detecting means) 9 is connected to the supply path 8. The pressure switch 9 is activated when the driving pressure of the power steering actuator 6 exceeds a predetermined value, and a predetermined supply signal is supplied. Is output to the controller 10. Here, the drive pressure of the power steering actuator 6 follows valves (not shown) built in the power steering actuator 6 when the steering of the vehicle is rapidly operated at a large steering angle such as when entering a garage. In this embodiment, the predetermined value is set to be equal to the driving pressure when the steering is set to almost the maximum steering angle in the present embodiment. That is, the pressure switch 9 outputs a predetermined replenishment signal to the controller 10 when the steering is set to almost the maximum steering angle when the vehicle speed is substantially zero.

The connection position of the pressure switch 9 is not limited to the supply path 8, but may be changed as appropriate as long as the drive pressure of the power steering actuator 6 can be detected. However, when connected to the supply path 8, the amount of oil in the supply path 8 is smaller than the amount of pressure oil guided from the second hydraulic pump 3 to the power steering actuator 6, and a detection error due to pulsation of hydraulic pressure is eliminated. This is advantageous because it can be performed.

The controller 10 receives the supply signal sent from the pressure switch 9 and receives the supply signal from the pressure switch 9.
The controller 10, the electromagnetic control valve 4, and the supply path 8 constitute a pressure oil supply unit 11 in the present embodiment. That is, the controller 10 outputs a drive signal in response to the supply signal sent from the pressure switch 9, so that the solenoid coil 4a of the electromagnetic control valve 4 is excited and the electromagnetic control valve 4 is switched from the a position to the b position. As a result, a part of the pressure oil discharged from the first hydraulic pump 2 is supplied to the power steering actuator 6 via the supply path 8. Here, the controller 10
Includes not only a CPU but also an analog-to-digital converter and other peripheral devices. In the case of the present embodiment, the output current to the electromagnetic control valve 4 is increased for a predetermined time, for example, 10 seconds.
There is a built-in timer that keeps running for a limited time.

In FIG. 1, reference numeral 12 denotes a check valve for preventing backflow of pressure oil and transmission of pressure shock from the power steering actuator 6 side to the first hydraulic pump 2 side.

Next, the operation of the cooling fan drive of the present embodiment will be described. In the cooling fan drive device of the present embodiment, the hydraulic oil discharged from the first and second hydraulic pumps 2 and 3 that are rotationally driven by the engine 1 are guided to the cooling fan drive motor 5 and the power steering actuator 6, respectively. Thus, the cooling fan (not shown) connected to the output shaft of the cooling fan drive motor 5 rotates to cool the cooling water passing through the radiator, and a desired assist force acts on the steering device of the vehicle. In this case, the entire pressure oil from the first hydraulic pump 2 is supplied to the cooling fan drive motor 5 during normal running of the vehicle, but only when the vehicle is rapidly turned to the vicinity of the maximum steering angle. A part is supplied to the power steering actuator 6 by the action of the switch 9 and the pressure oil supply means 11. Hereinafter, the details of the supply operation will be described with reference to FIG.

As shown in FIG. 2, when the engine 1 is started and each of the hydraulic pumps 2 and 3 starts rotating, the controller 10 first determines whether or not a built-in timer is operating (step S1). If it is determined that the timer is stopped, it is determined whether a replenishment signal is being sent from the pressure switch 9 (step S2). When the supply signal is not transmitted from the pressure switch 9, the driving pressure of the power steering actuator 6 does not reach the predetermined value, for example, the running state of the vehicle operates the steering wheel rapidly and at a large steering angle. It is determined that the vehicle is in the normal running state without any trouble, and the process returns to step S1 in which the operation of the timer is monitored again without holding the electromagnetic control valve 4 at the a position without issuing a drive signal to the electromagnetic control valve 4 (step S1). S3). By the above processing, the entire amount of the pressure oil discharged from the first hydraulic pump 2 is continuously supplied to the cooling fan drive motor 5 during the normal running of the vehicle.

On the other hand, when the driving pressure of the power steering actuator 6 exceeds a predetermined value, the steering wheel is rapidly turned to the vicinity of the maximum steering angle when the vehicle is stopped in a garage or when traveling at an extremely low speed. Upon detection of the pressure switch 9, a timer built in the controller 10 is started (steps S2 and S4). After the timer is started, regardless of whether or not the replenishment signal from the pressure switch 9 is continued, the timer is operated for a predetermined time, for example, 1 in the illustrated example.
The electromagnetic control valve 4 from the controller 10 until 0 seconds is reached
, And the electromagnetic control valve 4 is held at the B position (steps S5, S6, S1). This allows
For a certain period of time, the amount of pressure oil supplied from the first hydraulic pump 2 to the cooling fan drive motor 5 is reduced, and the remaining amount of oil discharged from the hydraulic pump is supplied to the power steering actuator 6 from the supply path 8.

When the operation time of the timer reaches a predetermined time, the timer is stopped (step S7), whereby the transmission of the drive signal from the controller 10 to the electromagnetic control valve 4 is terminated, and the electromagnetic control valve 4 is moved to the position A. (Step S
3). Thereby, the supply of the pressure oil from the first hydraulic pump 2 to the power steering actuator 6 is completed,
Unless the pressure switch 9 detects the drive pressure exceeding the predetermined limit value again, the entire amount of the pressure oil from the first hydraulic pump 2 is continuously supplied to the cooling fan drive motor 5.

As described above, in the cooling fan drive device of the present embodiment, the first operation is performed when the vehicle is put into a garage where the load on the power steering actuator 6 is increased as compared with the normal traveling.
The hydraulic oil is also supplied from the hydraulic pump 2 to the power steering actuator 6. Therefore, the discharge capacity of the second hydraulic pump 3 is reduced by the required discharge capacity during engine idling when the load on the power steering actuator 6 is maximized. The power steering actuator 6 is always supplied with a necessary and sufficient amount of pressure oil even if the discharge capacity is set small by the amount of supply of the pressure oil from the first hydraulic pump 2. You. Therefore, it is possible to reduce the driving energy by changing the second hydraulic pump 3 to one having a smaller capacity than the conventional one.

In addition, the supply of pressure oil from the first hydraulic pump 2 to the power steering actuator 6 side eliminates the need for providing an expensive auxiliary air intake valve in the intake system of the engine 1. can get.

That is, as described in the prior art, when the discharge capacity of the second hydraulic pump 3 is determined so that the steering can be set to almost the maximum steering angle during idling, the first and second hydraulic pumps 2 , 3 are large. Therefore, it is necessary to install an auxiliary air intake valve in the intake system to appropriately increase the amount of inflow air, thereby increasing the idling speed.
However, according to this embodiment, since the discharge capacity of the second hydraulic pump 3 can be reduced, the total maximum value of the pump absorption torques of the first and second hydraulic pumps can be reduced as compared with the conventional case. Therefore, even if the load on the power steering side during idling increases and pressure oil is replenished from the first hydraulic pump 2, the overall load on both pumps is reduced as compared with the conventional case. It is possible to avoid the stop of the engine 1 during idling without the provision.

In this embodiment, the supply of hydraulic oil from the first hydraulic pump 2 reduces the amount of hydraulic oil supplied to the cooling fan drive motor 5 to lower the cooling performance of the cooling fan. Since the frequency of replenishment from the first hydraulic pump 2 is low and the replenishment time is short, there is no possibility of causing overheating. In this regard, especially the controller 10
Since the replenishment time of the pressurized oil is limited to 10 seconds by the timer, the possibility of overheating is more reliably eliminated.

Here, when the pressure oil supply amount to the cooling fan drive motor 5 when the electromagnetic control valve 4 is switched to the position B is α, and the pressure oil supply amount to the supply path 8 side is β. The ratio α: β of the two may be appropriately changed according to the capacity of the second hydraulic pump 3 by the throttle 4 b in the electromagnetic control valve 4, and as an example, it may be set to about 2: 8. Further, when the electromagnetic control valve 4 is at the position B, the supply of the pressure oil to the cooling fan drive motor 5 may be completely stopped. That is, during the replenishment operation, the entire amount of the pressure oil discharged from the first hydraulic pump 2 may be guided to the power steering actuator 6 side.

In the above description, the discharge oil of the first hydraulic pump 2 is always flown into the hydraulic motor 5 to drive the fan. However, when the electromagnetic control valve 4 is set at the 3 position and the engine cooling water temperature is low, The discharge oil of the hydraulic pump 2 may be returned to the full tank.

[0025]

As described above, in the cooling fan drive of the present invention, the pressure detecting means detects an increase in the load on the power steering side when the vehicle is put into a garage or the like, and the first hydraulic pump responds accordingly. Since the hydraulic oil is supplied, even if the discharge amount of the second hydraulic pump for power steering is set to be smaller by the amount of supply of hydraulic oil from the first hydraulic pump, the power steering actuator is always sufficient. A quantity of pressurized oil is supplied. Therefore, according to the present invention, there is obtained an excellent effect that the second hydraulic pump can be miniaturized to reduce the driving energy while supplying a sufficient amount of pressure oil to the cooling fan drive motor and the power steering actuator. Can be

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a processing procedure of a controller illustrated in FIG. 1;

[Explanation of symbols]

 2 First hydraulic pump 3 Second hydraulic pump 4 Electromagnetic control valve 5 Cooling fan drive motor 6 Actuator for power steering 8 Supply path 9 Pressure switch (pressure detection means) 11 Pressure oil supply means

Claims (1)

(57) [Claims] 1. A first hydraulic pump for supplying hydraulic oil to a hydraulic motor for driving a cooling fan of a radiator, a second hydraulic pump for supplying hydraulic oil to a power steering actuator, and driving of the power steering actuator Pressure detection means for detecting that the pressure has reached a predetermined value; and when the pressure detection means has detected the predetermined value, at least a part of the pressure oil discharged from the first hydraulic pump is supplied to the power steering. Fan driving device comprising pressure oil replenishing means for replenishing a hydraulic actuator.