JPH05171934A - Revolution speed control device for hydraulic drive cooling fan in integrated hydraulic pressure supply device - Google Patents

Abstract

PURPOSE:To prevent generation of noises which may caused by abrupt change of a revolution speed of a cooling fan device even when a used pressure is abruptly changed in a hydraulic driving device. CONSTITUTION:A revolutional speed control device for a cooling fan device is adapted to an integrated hydraulic pressure supply device which has an operation oil supplying source 34, a supplying passage 18, a cooling fan device 24 provided on the way thereof, an LSD 20 connected to the supplying passage 18 on its downstream, and a returning passage 14 for returning the operation oil from the LSD 20 to the supplying source 34. A pressure sensor 54 detects a used hydraulic pressure Ps of the LSD 20. A control device 70 controls differential pressure in respect to a hydraulic motor 38 of the cooling fan device. The control device 70 computes Psf while carrying out low-pass filter treatment of a signal which indicates the hydraulic pressure Ps, and controls such that the differential pressure in respect to the hydraulic motor 38 is set between an operation oil supplying pressure Pp and the pressure Psf.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated hydraulic pressure supply device for a vehicle such as an automobile, and more particularly to a rotation speed control device for a hydraulic drive type cooling fan device in the integrated hydraulic pressure supply device.

[0002]

2. Description of the Related Art As one of integrated hydraulic pressure supply devices for vehicles such as automobiles, a hydraulic oil supply source including a hydraulic pump, a reservoir, and the like, as described in, for example, JP-A-61-215417, is used. A hydraulic fan type cooling fan device for an engine including a hydraulic oil supply passage for supplying high-pressure hydraulic oil from an oil supply source, a hydraulic motor provided in the middle of the hydraulic oil supply passage for rotationally driving a fan, and a cooling fan device. It has a power steering device connected to the hydraulic oil supply passage on the downstream side and a hydraulic oil return passage for returning the hydraulic oil from the power steering device to the hydraulic oil supply source. 2. Description of the Related Art Integrated hydraulic supply devices configured to drive a cooling fan device and a power steering device with hydraulic oil have been conventionally known.

According to such a hydraulic pressure supply device, since the hydraulic oil supply sources of the cooling fan device and the power steering device are integrated, compared with the case where the hydraulic oil supply source is provided in each of the cooling fan device and the power steering device. Therefore, the number of parts such as a pump can be reduced, and fuel consumption can be improved.

[0004]

However, in the conventional integrated hydraulic supply device described in the above publication, hydraulic drive devices such as a cooling fan device and a power steering device are connected in series by a hydraulic oil supply passage. Therefore, when the hydraulic pressure used in the hydraulic drive device changes abruptly, the differential pressure across the hydraulic motor of the cooling fan device also changes abruptly, which causes the rotation speed of the cooling fan device to change abruptly. Unpleasant noise may occur due to the movement. In particular, such a problem is that hydraulic pressure such as a hydraulic control type LSD (Limited Slip Differential) in which the working pressure fluctuates more rapidly than in the case where the hydraulic drive is a hydraulic drive in which the working pressure does not fluctuate abruptly. This is remarkable in the case of a drive device.

In view of the above-mentioned problems in the conventional integrated hydraulic supply device in which the hydraulic oil supply sources of the cooling fan device and the other hydraulic drive device are integrated, the present invention uses the hydraulic pressure used in the hydraulic drive device. To provide an improved rotational speed control device for a hydraulic drive type cooling fan device so that no unpleasant noise is generated due to a change in the rotational speed of the cooling fan device even if the rotational speed fluctuates rapidly. Has a purpose.

[0006]

According to the present invention, the above-mentioned object is to provide a hydraulic oil supply source, a hydraulic oil supply passage for supplying high-pressure hydraulic oil from the hydraulic oil supply source, and the hydraulic oil. A hydraulic drive cooling fan device for an engine provided in the middle of the supply passage, a hydraulic drive device connected to the hydraulic oil supply passage downstream of the cooling fan device, and a hydraulic oil from the hydraulic drive device. A hydraulic oil return passage for returning to the hydraulic oil supply source, wherein the cooling fan device is provided in the middle of the hydraulic oil supply passage for rotating a fan; a bypass passage bypassing the hydraulic motor; An integrated hydraulic pressure supply device including a differential pressure control means provided in the middle of the bypass passage serves as a rotation speed control device for controlling the rotation speed of the cooling fan device to detect the working oil pressure Ps of the hydraulic drive device. Pressure detection means and a signal indicating the pressure Ps supplied from the pressure detection means are low-pass filtered to calculate Psf, and the differential pressure control means is controlled to substantially reduce the differential pressure across the hydraulic motor. And a control means configured to control the difference Pp-Psf between the pressure Pp of the hydraulic oil supplied from the hydraulic oil source and the pressure Psf.

[0007]

According to the above-described structure, the rotation speed control device includes the pressure detection means for detecting the working oil pressure Ps of the hydraulic drive device,
Control means for controlling the differential pressure control means of the cooling fan device, and the control means supplies the pressure Ps supplied from the pressure detection means.
Low-pass filter the signal indicating to calculate Psf,
The differential pressure before and after the hydraulic motor is substantially the supply pressure Pp
Since the pressure Psf is configured to be controlled to a difference Pp-Psf between the pressure Psf and the pressure Psf, the pressure Psf does not change abruptly even when the hydraulic pressure Ps used by the hydraulic drive device changes abruptly, and the differential pressure Pp across the hydraulic motor is increased. -Psf does not change abruptly, so that the generation of noise due to the abrupt change in the rotation speed of the fan of the cooling fan device is reliably prevented.

[0008]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram showing an integrated hydraulic pressure supply device in which an embodiment of a rotation speed control device according to the present invention is incorporated.

In FIG. 1, reference numeral 10 designates a reservoir for storing hydraulic oil. One end of the suction passage 12 and one end of the hydraulic oil return passage 14 are connected to the reservoir 10. The other end of the suction passage 12 is connected to the suction side of a pump 16 driven by an engine (not shown). One end of a hydraulic oil supply passage 18 for supplying high-pressure hydraulic oil is connected to the discharge side of the pump 16, and the other ends of the hydraulic oil supply passage and the hydraulic oil return passage 14 are hydraulic control of a structure known per se. Connected to formula LSD20. Although not shown in detail in the figure, the LSD 20 is controlled by its electronic control unit so as to limit the differential action and increase the driving force of one of the left and right driving wheels as needed.

In the middle of the hydraulic oil supply passage 18, the flow control (FC) valve 22 and the cooling fan device 2 are seen from the upstream side.
4. A flow rate control (FC) valve 26 is sequentially provided in series. The flow rate control valve 22 is a flow priority valve, and the flow rate Q1 of the hydraulic oil of the flow rate Q0 supplied to it
Is supplied to the cooling fan device 24, and the remaining working oil is returned to the suction passage 12 through the passage 28. Further, a relief passage 32 having a relief valve 30 in the middle is connected between the hydraulic oil supply passage between the pump 16 and the flow control valve 22 and the passage 28, whereby the pump 16 moves to the flow control valve 22. The pressure of the supplied hydraulic oil is maintained below a predetermined maximum value.

Thus, the reservoir 10, the pump 16, the flow control valve 22, the relief valve 30 and the like supply the high pressure hydraulic oil having a predetermined maximum value or less to the cooling fan device 24 and the like at the control flow rate Q1 in the pattern shown in FIG. A hydraulic oil supply source 34 to be supplied is configured. The flow control valve 22 and the relief valve 30 may be integrated with the pump 16.

The cooling fan device 24 includes a fan 36, a hydraulic motor 38 provided in the middle of the hydraulic oil supply passage 18 for rotating the fan 36, and a hydraulic oil supply passage upstream and downstream of the hydraulic motor. It includes a bypass passage 40 that is connected for communication, and an electromagnetic differential pressure control valve 42 provided in the middle of the bypass passage. The differential pressure control valve 42 has a solenoid 44, and if the control current supplied to the solenoid from a control device (not shown) is Ifan and the flow rate of the hydraulic oil passing through the hydraulic motor 38 is Qfan, The flow passage (Q1-Qfan) of hydraulic oil is passed through the bypass passage 40.
The pressure difference ΔP before and after the hydraulic motor is controlled in proportion to the control current Ifan.

Assuming that the rotational speed of the hydraulic motor 38 is Nfan, there is a relationship of Nfan = Kq.multidot.Qfan = Kp.multidot. (. DELTA.P) ^1/2 where Kq and Kp are proportional constants. By controlling ΔP, the rotation speed Nfan is halved of the control current Ifan.
Control to a value proportional to the power.

The flow control valve 26 is also a flow priority valve, and among the hydraulic oil of the flow rate Q1 supplied to the flow control valve 26, the hydraulic fluid of the flow rate Q2 is set to L according to the pattern shown in FIG.
It is configured to be supplied to the SD20 and to guide the remaining amount of hydraulic oil of the flow rate Q3 (= Q1-Q2) to the hydraulic oil return passage 14 via the passage 46.

The hydraulic oil supply passage 18 between the cooling fan device 24 and the flow control valve 26 is provided with a pressure sensor 54 for detecting the pressure Ps of the hydraulic oil in the passage. An engine (not shown) is provided with a rotation speed sensor 56 that indirectly detects the rotation speed N of the pump 16 by detecting the rotation speed of the engine.

The differential pressure control valve 42 is controlled by the electronic control unit 70. The electronic control unit 70 is shown in FIG.
It includes a microcomputer 72 as shown in FIG. The microcomputer 72 may have a general structure as shown in FIG. 4, and includes a central processing unit (CPU) 74 and a read only memory (ROM) 7.
6, a random access memory (RAM) 78, an input port device 80, and an output port device 82, which are connected to each other by a bidirectional common bus 84.

In the illustrated embodiment, the input port device 8
At 0, a signal indicating the pressure Ps from the pressure sensor 54, a signal indicating the rotation speed N of the pump from the rotation speed sensor 56, and a signal indicating whether the air conditioner is operating from the air conditioner 58,
A signal indicating the throttle opening is input from the throttle opening sensor 60, and a signal indicating the engine cooling water temperature T is input from the water temperature sensor 62. The input port device 80 appropriately processes the signal input thereto, and the ROM 7
The processed signal is output to the CPU and the RAM 78 according to the instruction of the CPU 74 based on the program stored in the CPU 6. The ROM 76 stores the control program shown in FIG. 5 and maps corresponding to the graphs shown in FIGS. 6 to 11. The CPU 74 is adapted to perform various operations and signal processing based on the control program shown in FIG. 5, as will be described later. Output port device 82
According to an instruction from the CPU 74, the control signal is output to the solenoid 44 of the differential pressure control valve 42 via the drive circuit 86.

The operation of the illustrated embodiment will now be described with reference to the flow chart shown in FIG.

First, in step 10, the pressure sensor 54 indicates a signal indicating the pressure Ps, the rotation speed sensor 56 indicates a signal indicating the rotation speed N of the pump, and the air conditioner 58 indicates whether or not the air conditioner is operating. The signal, the signal showing the throttle opening from the throttle opening sensor 60, and the signal showing the cooling water temperature T of the engine from the water temperature sensor 62 are read, and then the process proceeds to step 20.

In step 20, it is judged whether or not the air conditioner 58 is operating, and when it is judged that the air conditioner is operating, the routine proceeds to step 60, where the air conditioner is not operating. If it is determined that there is not, the process proceeds to step 30.

In step 30, it is judged whether the engine is in the idle state or not based on the signal from the throttle opening sensor 60. If it is judged that the engine is in the idle state, the step is carried out. When it is determined that the vehicle is not in the idle state, the process proceeds to step 50.

At step 40, the control amount K1 is calculated from the map corresponding to the graph shown in FIG. 6, and similarly at step 50, the control amount K1 is calculated from the map corresponding to the graph shown in FIG. K1 is calculated.

In step 60, it is judged whether or not the engine is in the idle state, and when it is judged that the engine is in the idle state, step 80
If it is determined that the vehicle is not in the idle state, the process proceeds to step 70.

In step 70, the control amount K1 is calculated from the map corresponding to the graph shown in FIG. 8. Similarly, in step 80, the control amount K1 is calculated from the map corresponding to the graph shown in FIG. K1 is calculated.

Thus, steps 40, 50, 70 and 80
In this case, the control amount K1 is calculated based on whether the air conditioner is operating, whether the engine is in the idle state, and the cooling water temperature of the engine.

In step 90, the control amount K2 based on the rotational speed N of the pump 16 is calculated based on the map corresponding to the graph shown in FIG. 10, and in step 100, the control amount K2 is calculated.
The control amount K3 based on the pressure Ps is calculated based on the map corresponding to the graph shown in FIG. 1, and then the process proceeds to step 102. The pattern of the graph of FIG. 10 is a pattern set in order to prevent an excessive load from being applied to the pump 16.

At step 102, the control amount K3 calculated at step 100 is differentiated to obtain K3d.
ot is calculated, and in step 104, it is determined whether or not K3dot is 0 or more, that is, whether or not the control amount K3 is in the process of increasing, and it is determined that K3dot ≧ 0. When it is determined that the control amount K3f is not 0, the control amount K3f is low-pass filtered in step 106 to calculate the control amount K3f, and then the process proceeds to step 112. ..

In step 110, the controlled variables K2 and K3
And the difference K4 (= K2-K3) is calculated, and step 11
In the case of 2, the difference K4 (= K2-K3) between the controlled variables K2 and K3f
f) is calculated.

In the next step 120, the control amount K4
Is determined to be negative, and if it is determined that K4 <0, then K4 is 0 in step 130.
Is set to step 140, the process proceeds to step 140, and when it is determined that K4 <0 is not satisfied, step 140 is directly executed.
Go to.

In step 140, the controlled variable K1 is K
It is determined whether or not 4 or less, and when it is determined that K1 ≤ K4 is not satisfied, the routine proceeds to step 160,
If it is determined that K1≤K4, the routine proceeds to step 150.

In step 150, the cooling fan device 2
The control current Ifan supplied to the solenoid 44 of the differential pressure control valve 42 of No. 4 is set to K1, the control current Ifan is set to the control amount K4 in step 160, and the control current is set in the next step 170. Ifan is output to the solenoid 44, and then the process returns to step 10.

FIG. 12 is a schematic configuration diagram showing an integrated hydraulic pressure supply device in which another embodiment of the rotation speed control device according to the present invention is incorporated, and FIG. 13 is a differential pressure of the cooling fan device shown in FIG. It is a block diagram showing an electronic control unit which controls a control valve. In these figures, the parts corresponding to the parts shown in FIGS. 1 and 4 are designated by the same reference numerals as those shown in FIGS. 1 and 4.

In this embodiment, as shown in FIG. 12, the LSD 20 controls the hydraulic pressure to be used on the basis of the command pressure Pc from the electronic control unit 88 of the LSD 20 so that a differential action is performed as necessary. To limit the driving force of one of the left and right driving wheels. Further, as shown in FIGS. 12 and 13, the command pressure Pc from the electronic control unit 88 is output.
Is supplied to the input port device 82 of the electronic control unit 70.

Since the control achieved by the electronic control unit 70 in this embodiment is substantially the same as that in the above-described embodiment, the description of the flow chart corresponding to FIG. In the corresponding step, the controlled variable K3 is not calculated based on the map corresponding to the graph shown in FIG. 11, but is calculated based on the map corresponding to the graph shown in FIG.

Thus, according to the above-mentioned two embodiments, if the maximum pressure of the hydraulic oil that can be supplied by the hydraulic oil supply source 34 is Pp without the pump being overloaded, the maximum pressure Pp in step 90 is obtained. Is calculated, the control amount K3 corresponding to the pressure Ps or Pc consumed by the hydraulically controlled LSD 20 is calculated in step 100, and the control amount K3 is increased in steps 102 and 104. Whether the process is in progress or not is determined, and the control amount K3
Is increasing, in step 110, the control amount K4 corresponding to the differential pressure .DELTA.P for driving the hydraulic motor 38 is increased.
Is calculated as the difference between the two control quantities K2 and K3. If the control quantity K3 has not increased, the control quantity K3f is low-pass filtered in step 106 to calculate the processed control quantity K3f. , The controlled variable K4 is calculated as the difference between the two controlled variables K2 and K3f.

Therefore, when the hydraulic pressure used by the LSD 20 is reduced, the control amount K4 is calculated in step 112 based on the control amount K3f corrected to change gently in step 106. As shown in 15, even if the hydraulic pressure used by the LSD suddenly changes, the control amount K4
Does not change abruptly, so that the rotation speed of the fan 36 of the cooling fan device 24 changes abruptly and the generation of noise due to this is reliably avoided. The phantom line in FIG. 15 shows the change in the control amount K4 when calculated as the difference between the control amounts K2 and K3.

When the hydraulic pressure used by the LSD 20 is increased, the control amount K4 is calculated as the difference between the two control amounts K2 and K3 in step 110, so that the LSD is adjusted as shown in FIG. The control amount K4 is rapidly reduced in response to an increase in the demand for hydraulic pressure to ensure effective and reliable operation of the LSD.

Further, according to the above-mentioned two embodiments, in steps 20 to 80, information on whether the air conditioner is operating, whether the engine is in the idle state, and the cooling water temperature T of the engine are provided. Based on the above, a control amount K1 for optimally cooling the engine is calculated, and steps 140 to 170 are executed.
When K1 ≤ K4, the control current Ifan corresponding to K1 is output to the differential pressure control valve 42 to optimally cool the engine, and when K1> K4, the control current Ifan corresponding to K4 is reduced. By being output to the control valve, the hydraulic oil pressures Pp and L supplied by the hydraulic oil supply source 34 are supplied.
Pressure Ps consumed by SD or differential pressure Pp with Psf −
The hydraulic motor is driven by Ps or Pp-Psf, which cools the engine as effectively as possible without imposing an excessive load on the pump or the like.

The present invention has been described in detail with reference to specific embodiments, but the present invention is not limited to these embodiments, and various other embodiments are included within the scope of the present invention. It will be apparent to those skilled in the art that

For example, in the illustrated embodiment, the hydraulic drive device is a hydraulic control type LSD, but the hydraulic drive device may be a device other than the LSD as long as the operating hydraulic pressure changes with its operation. ..

[0042]

As is apparent from the above description, according to the present invention, the control means performs low-pass filter processing on the signal indicating the pressure Ps supplied from the pressure detection means to calculate Psf, and the control means before and after the hydraulic motor. Since the differential pressure is controlled to be substantially equal to the difference Pp-Psf between the hydraulic oil supply pressure Pp and the pressure Psf, the pressure Psf changes rapidly even if the hydraulic pressure Ps used by the hydraulic drive changes rapidly. Does not change, and the differential pressure Pp-Psf before and after the hydraulic motor does not change rapidly. Therefore, it is possible to reliably prevent the generation of noise due to the rapid change in the rotation speed of the fan of the cooling fan device. it can.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an integrated hydraulic pressure supply device in which an embodiment of a rotation speed control device according to the present invention is incorporated.

FIG. 2 is a graph showing a relationship between a rotational speed N of a pump and a control flow rate Q1 of hydraulic oil supplied to a cooling fan device or the like.

FIG. 3 is an inflow flow rate Q of a flow rate control valve for a hydraulically controlled LSD.
It is a graph which shows the relationship between 1 and control flow rate Q2.

FIG. 4 is a block diagram showing an electronic control device for controlling a differential pressure control valve of the cooling fan device shown in FIG.

5 is a flowchart showing a control flow achieved by the electronic control device shown in FIG.

FIG. 6 is a graph showing a relationship between a cooling water temperature T of the engine and a control amount K1 when the air conditioner is not operated and the engine is not in an idle state.

FIG. 7 is a graph showing the relationship between the engine coolant temperature T and the controlled variable K1 when the air conditioner is not operating and the engine is in the idle state.

FIG. 8 is a graph showing the relationship between the engine coolant temperature T and the controlled variable K1 when the air conditioner is operating and the engine is not in the idle state.

FIG. 9 is a graph showing the relationship between the engine coolant temperature T and the controlled variable K1 when the air conditioner is operating and the engine is in the idle state.

FIG. 10 is a graph showing the relationship between the rotational speed N of the pump and the control amount K2.

FIG. 11 is a graph showing the relationship between the pressure Ps in the hydraulic oil supply passage between the cooling fan device and the LSD and the control amount K3.

FIG. 12 is a schematic configuration diagram showing an integrated hydraulic pressure supply device in which another embodiment of the rotation speed control device according to the present invention is incorporated.

13 is a block diagram showing an electronic control device for controlling the differential pressure control valve of the cooling fan device shown in FIG.

FIG. 14 is a graph showing a relationship between a command pressure Pc and a control amount K3 with respect to LSD.

FIG. 15 is a graph showing an example of changes in control amounts K3, K3f, and K4.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Reservoir 14 ... Operating oil return passage 16 ... Pump 18 ... Operating oil supply passage 20 ... Hydraulic control type LSD 24 ... Cooling fan device 34 ... Operating oil supply source 42 ... Differential pressure control valve 54 ... Pressure sensor 70 ... Electronic control device

Claims (1)

[Claims] 1. A hydraulic oil supply fan, a hydraulic oil supply passage for supplying high-pressure hydraulic oil from the hydraulic oil supply source, and an engine hydraulic drive type cooling fan device provided in the middle of the hydraulic oil supply passage. A hydraulic drive device connected to the hydraulic oil supply passage on the downstream side of the cooling fan device, and a hydraulic oil return passage for returning the hydraulic oil from the hydraulic drive device to the hydraulic oil supply source, The cooling fan device includes an integrated hydraulic motor that is provided in the middle of the hydraulic oil supply passage to rotate a fan, a bypass passage that bypasses the hydraulic motor, and a differential pressure control means that is provided in the middle of the bypass passage. In the mold hydraulic pressure supply device, a rotation speed control device for controlling the rotation speed of the cooling fan device is provided, and pressure detection means for detecting the working oil pressure Ps of the hydraulic drive device and the pressure detection means are supplied. The signal indicating the force Ps is low-pass filtered to calculate Psf, and the differential pressure control means is controlled so that the differential pressure across the hydraulic motor is substantially the pressure of the hydraulic fluid supplied from the hydraulic fluid supply source. A rotational speed control device comprising control means arranged to control the difference Pp-Psf between Pp and said pressure Psf.