JP2001234948A - Fluid coupling device - Google Patents

Abstract

(57) Abstract: A smooth relative rotation between a driving member and a driven member is allowed when the ambient temperature is low, and the relative rotation between the driving member and the driven member is prevented when the ambient temperature is high. A compact and lightweight fluid coupling device. SOLUTION: The fluid coupling device is provided with a housing 10 which rotates integrally with a driving member, a shaft 21 which is rotatably assembled to the housing 10 and rotates integrally with a driven member, Rotating positive displacement pump elements 31, 32 pumped by relative rotation
A communication passage 18 formed in the housing 10 for communicating the suction port and the discharge port; a control valve 40 for controlling the flow rate of hydraulic oil returning from the discharge port to the suction port through the communication passage 18; A temperature sensing member 50 for closing and driving the control valve 40 accordingly is provided to control the relative rotation between the housing 10 and the shaft 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid coupling device used to rotationally drive, for example, a cooling fan disposed behind a radiator for an automobile.

[0002]

2. Description of the Related Art A fluid coupling device of this type is disclosed, for example, in Japanese Patent Laid-Open Publication No. Sho 61-262234. In the fluid coupling device disclosed in the publication, a driving member driven by an engine is used. Torque is transmitted to the driven member to which the cooling fan is attached by viscous fluid (high-viscosity hydraulic oil) interposed between the labyrinth-shaped torque transmitting surfaces engaged with each other.

[0003]

In the fluid coupling device disclosed in the above publication, the torque transmission from the driving member to the driven member is performed by the viscosity of the hydraulic oil. Always accompany it. Therefore, when such a fluid coupling device is used for a rotation drive unit of a cooling fan, the cooling fan rotates together even when the rotation of the cooling fan is unnecessary, causing power loss of the engine and deterioration of warm-up property. Further, in the fluid coupling device of the above-mentioned publication, in order to transmit a large torque, it is necessary to enlarge a labyrinth-like torque transmission surface,
The fluid coupling device increases in size.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to address the above-described problems, and includes a housing for rotating a fluid coupling device integrally with a driving member or a driven member; A shaft that is rotatably assembled and rotates integrally with the driven member or the driving member; a rotary displacement type pump element that is housed in the housing and is pumped by relative rotation of the housing and the shaft; A communication passage formed in the housing and communicating a suction port formed in a suction portion of the pump element with a discharge port formed in a discharge portion of the pump element; and a communication passage interposed in the communication passage and passing through the communication passage. A control valve for controlling the flow rate of hydraulic oil returning from the discharge port to the suction port; It said control valve and a temperature-sensitive member for closing driven Flip was configured to control the relative rotation of the shaft and the housing in accordance with the ambient temperature.
In this case, it is also possible to add a relief function to the control valve, which permits the return from the discharge port to the suction port when the hydraulic pressure in the discharge port becomes equal to or more than a set value.

[0005]

In the fluid coupling device according to the present invention, since the temperature-sensitive member drives the control valve to close in response to the rise in the ambient temperature, when the ambient temperature is low, the control valve connects the communication passage. It is open to allow hydraulic oil to return from the discharge port to the suction port through the communication passage. Therefore, smooth rotation of the pump element within the housing is allowed, smooth relative rotation of the housing and the shaft (the driving member and the driven member) is allowed, and almost no rotational torque is transmitted between the housing and the shaft.
Therefore, when the fluid coupling device is used for a rotation drive unit of a cooling fan, when the water temperature of the radiator is low and the ambient temperature is low, it is possible to prevent the rotation of the cooling fan and reduce the power loss of the engine. And the warm-up property of the engine can be improved.

Further, when the ambient temperature is high, the temperature-sensitive member closes the communication passage by driving the control valve to close, so that the hydraulic oil does not return to the suction port from the discharge port through the communication passage. For this reason, rotation of the pump element in the housing is prevented, relative rotation of the housing and the shaft (the driving member and the driven member) is prevented, and the housing and the shaft rotate integrally. Therefore, when the fluid coupling device is used for the rotation drive unit of the cooling fan, when the water temperature of the radiator is high and the ambient temperature is high, the cooling fan can be driven to rotate integrally with the drive member, A sufficient air volume can be guided to the radiator.

Further, in the fluid coupling device according to the present invention, the control valve is closed and driven by the temperature sensing member to close the communication passage, thereby preventing the rotation of the pump element in the housing and causing the relative movement of the housing and the shaft. Since the rotation is prevented and the housing and the shaft rotate integrally, even when transmitting a large torque, there is no need to increase the size of each component. Small size and light weight are possible.

In implementing the present invention, when the control valve is provided with a relief function for permitting recirculation from the discharge port to the suction port when the hydraulic pressure in the discharge port exceeds a set value, When the housing and the shaft are rotating integrally and the rotation speed is high and the transmission torque between the housing and the shaft is equal to or greater than a set value, the hydraulic pressure in the discharge port is equal to or greater than the set value, and the control valve is operated in relief. For this reason, the hydraulic oil flows back from the discharge port to the suction port, allowing rotation of the pump element in the housing, and allowing relative rotation between the housing and the shaft. Therefore, when the fluid coupling device is used as a rotation drive unit of a cooling fan, the cooling fan can be prevented from being driven to rotate at high speed, and power loss of the engine can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a cooling fan device for a vehicle including a fluid coupling device (fan coupling) A according to the present invention, in which a pulley P driven by an engine E is connected via a fluid coupling device A. The cooling fan F is assembled. The pulley P
Is adapted to rotate integrally with a shaft Pa mounted on the shaft center, and the water pump (not shown) is driven by the shaft Pa.

[0010] As shown in FIG.
This is for rotationally driving a cooling fan F disposed behind a radiator R for cooling the cooling water of the engine E. As shown in FIGS. 1 and 2, the cooling fan F is connected to a pulley P and integrally rotates. A housing 21, a shaft 21 rotatably mounted on the housing 10 and rotating integrally with the cooling fan F, an outer rotor 31 and an inner rotor 32 mounted in the housing 10, and a control valve 40. ing.

The housing 10 is, as shown in FIG.
Body 1 liquid-tightly joined via seal ring 13
1 and a cover 12 and are integrally connected by bolts 14. Also, the housing 10
Inside the outer rotor 31 and the inner rotor 3
2 is formed, and a discharge port 16 and a suction port 17 are formed in an arc shape on both front and rear end surfaces of the cylindrical space 15. The body 11 of the housing 10 has a communication passage 18 that connects the discharge port 16 and the suction port 17.

The shaft 21 is rotatably mounted on the housing 10 and has a front end (a portion formed with a two-sided width and a screw) 21a protruding forward from the housing 10, and is provided at the front end 21a. The cooling fan F is integrally supported and rotates integrally with the cooling fan F. In addition, the shaft 21 is formed by a spacer 22 and an inner rotor 3 which are integrally attached to a middle portion by a ring 22.
2 and is restricted from moving in the axial direction.
An oil seal 2 is provided between the shaft 21 and the body 11.
The oil seal 24 is intercepted by a clip 25 fitted to the body 11.

Outer rotor 31 and inner rotor 3
Reference numeral 2 denotes a rotary displacement type pump element which is pumped by the relative rotation of the housing 10 and the shaft 21.
The low-viscosity hydraulic oil fed under pressure flows from the discharge port 16 to the suction port 17 through the communication passage 18.

The outer rotor 31 has a circular outer periphery, is rotatably mounted in the cylindrical space 15 of the housing 10, and meshes with the outer periphery of the inner rotor 32 on the inner periphery to form an inner rotor 32. Thus, a working chamber 33 whose volume is increased or decreased by rotation is formed. The inner rotor 32 is fitted to an outer spline formed on the outer periphery of the shaft 21 by an inner spline formed on the inner periphery, and rotates integrally with the shaft 21.

The control valve 40 is interposed in the communication passage 18 and controls the flow rate of the hydraulic oil returning from the discharge port 16 to the suction port 17 through the communication passage 18. A valve body 41 movably mounted on the housing 19 and a spring 42 connected at one end to the valve body 41. The ambient temperature (radiator) is controlled by a thermo-wax (temperature-sensitive member) 50 mounted on the housing 10. The closing drive is performed in response to an increase in the temperature of the wind passing through R).

As shown in FIGS. 4A and 4C, the valve element 41 opens the communication passage 18 by being accommodated in the mounting hole 19, and as shown in FIG. 4B. Mounting hole 19
The communication passage 18 is closed by projecting from the communication port 18, and a slope 41 a is formed at a portion receiving the oil pressure in the discharge port 16. The oil pressure in the discharge port 16 is opposed to the spring force of the spring 42. To work.

The other end of the spring 42 is connected to a plate 51 which moves in the mounting hole 19 by expanding and contracting the thermowax 50 according to the ambient temperature.
The function of transmitting the expansion and contraction of the thermowax 50 from the plate 51 to the valve body 41, and the state where the thermowax 50 expands and the valve body 41 closes the communication passage 18 (FIG. 4B).
When the hydraulic pressure in the discharge port 16 becomes equal to or higher than the set value, the valve body 41 contracts to retract the valve element 41 from the communication passage 18 and allows the return of the hydraulic oil from the discharge port 16 to the suction port 17. It has a relief function.

In this embodiment constructed as described above, when the water temperature of the radiator R is low and the ambient temperature is low, as shown in FIG.
0 is contracted, the control valve 40 opens the communication passage 18, and the low-viscosity hydraulic oil is supplied from the discharge port 16 to the communication passage 1.
Reflux to the suction port 17 through 8 is permitted. For this reason, both rotors 31 and 3 in housing 10
2, the housing 10 and the shaft 21 (the pulley P and the cooling fan F) are allowed to rotate smoothly, and little rotation torque is transmitted between the housing 10 and the shaft 21. Therefore, it is possible to prevent the cooling fan F from being driven to rotate, so that the power loss of the engine E can be reduced and the warm-up property of the engine E can be improved.

When the water temperature of the radiator R is high, the ambient temperature is high, and the engine E is driven at a low speed (for example, when the engine speed is about 2500 rpm and the oil pressure in the discharge port 16 is less than a set value). 4)
As shown in (b), the control valve 40 is driven to close by the expansion of the thermowax 50 to close the communication passage 18, so that low-viscosity hydraulic oil flows from the discharge port 16 to the suction port 17 through the communication passage 18. No reflux. For this reason, rotation of both rotors 31 and 32 in housing 10 is prevented, and relative rotation of housing 10 and shaft 21 (pulley P and cooling fan F) is prevented.
0 and the shaft 21 rotate integrally. Therefore, the cooling fan F can be driven to rotate integrally with the pulley P, and a sufficient air volume can be guided to the radiator R.

When the water temperature of the radiator R is high, the ambient temperature is high, and the engine E is driven at a high speed, if the oil pressure in the discharge port 16 exceeds a set value,
As shown in FIG. 4C, the expansion of the thermowax 50 pushes the plate 51, but the valve body 4
1 retreats from the communication passage 18 and the control valve 40 opens the communication passage 18 (the control valve 40 performs a relief operation). For this reason,
The low-viscosity hydraulic oil returns from the discharge port 16 to the suction port 17 through the communication path 18 to allow the rotation of the rotors 31 and 32 in the housing 10 and the relative rotation of the housing 10 and the shaft 21. Therefore, it is possible to prevent the cooling fan F from being driven to rotate at high speed, and it is possible to reduce the power loss of the engine E.
At this time, both rotors 3 are in the relief operation state.
1 and 32 rotate to operate the pump, so that the cooling fan F
Can be kept at the set required number of revolutions,
Necessary cooling performance can be secured.

In the fluid coupling device A of the present embodiment, the control valve 40 is driven to be closed by the thermowax 50 to close the communication passage 18 so that the housing 1
Since the rotation of both the rotors 31 and 32 within 0 is prevented, the relative rotation of the housing 10 and the shaft 21 is prevented, and the housing 10 and the shaft 21 rotate integrally. Also in the case of transmission, it is not necessary to increase the size of each component, and it is possible to reduce the size and weight as compared with the conventional fluid coupling device.

In the above embodiment, the fluid coupling device A
The housing 10 is configured to rotate integrally with the pulley P (drive member), and the shaft 21 is configured to rotate integrally with the cooling fan F (driven member). The housing 10 of A may be configured to rotate integrally with the driven member, and the shaft 21 may be configured to rotate integrally with the driving member. Further, in the above embodiment, the outer rotor 31 and the inner rotor 32 are employed as the rotary displacement type pump elements. However, it is also possible to employ a rotor and a vane instead.

[Brief description of the drawings]

FIG. 1 is a view schematically showing an embodiment of an automotive cooling fan device including a fluid coupling device according to the present invention.

FIG. 2 is a detailed enlarged sectional view of the fluid coupling device shown in FIG.

FIG. 3 is a front view showing a relationship between a discharge port and a suction port provided in a housing of the fluid coupling device shown in FIG. 2 and both rotors.

FIG. 4 is an operation explanatory view taken along line 4-4 in FIG. 3;

[Explanation of symbols]

10 housing, 11 body, 12 cover, 16
... discharge port, 17 ... suction port, 18 ... communication passage, 21
... Shaft, 31, 32 ... Outer rotor, inner rotor (pump element), 33 ... Working chamber, 40 ... Control valve, 50 ... Thermo wax (temperature sensing member), A ... Fluid coupling device, F ... Cooling fan (Driven) R) radiator, P ... pulley (drive member).

Claims (2)

[Claims] 1. A housing that rotates integrally with a driving member or a driven member, a shaft that is rotatably assembled to the housing and that rotates integrally with the driven member or the driving member, and is housed in the housing. A rotary displacement pump element that is pumped by the relative rotation of the housing and the shaft; a suction port formed in the housing and formed in a suction part of the pump element; and a discharge part formed in a discharge part of the pump element. A communication valve that communicates with the discharge port, a control valve that is interposed in the communication path, and controls a flow rate of hydraulic oil that returns from the discharge port to the suction port through the communication path, and is mounted on the housing. A temperature-sensing member that closes and drives the control valve in response to an increase in the ambient temperature. A fluid coupling device that controls the relative rotation of the shaft. 2. The control valve according to claim 1, further comprising a relief function for allowing a return from the discharge port to the suction port when the hydraulic pressure in the discharge port becomes equal to or higher than a set value. Fluid coupling device.