JP2574946Y2 - Fan coupling - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan coupling used for a cooling fan drive of an internal combustion engine for a vehicle, and more particularly to a fan coupling using a viscous fluid as a power transmission medium.

[0002]

2. Description of the Related Art In general, a fan coupling of this type has a housing in which a viscous fluid is sealed, in which a rotor integrally connected to a drive shaft is rotatably mounted, and a viscous fluid supplied to a gap between the housing and the rotor. The transmission ratio of torque from the rotor to the housing is adjusted by increasing or decreasing the amount of torque. In the case of a fan coupling of the type that detects the temperature of the cooling water of the engine and adjusts the transmission ratio of the torque according to the temperature, the storage chamber for storing the viscous fluid inside the housing is a rotor or a housing. The storage chamber is provided with a variable volume means for adjusting the substantial storage volume of the storage chamber in accordance with a change in the ambient temperature.

Japanese Patent Application Laid-Open No. Sho 60-164615 discloses a fan coupling in which a storage chamber is provided integrally with a rotor, and a piston is provided in the storage chamber as a volume changing means.

[0004]

However, in the case of the above-described conventional fan coupling, the storage chamber for storing the viscous fluid is provided integrally with the rotor or the housing and rotates with the rotation of the drive shaft. However, there is a problem that the viscous fluid in the storage chamber flows during the operation and the liquid surface fluctuates, and the amount of the viscous fluid supplied to the gap between the housing and the rotor becomes unstable. In the above-mentioned fan coupling, it is not expected to control the torque transmission ratio with high accuracy because the supply amount of the viscous fluid is not stable.

Further, as another conventional fan coupling, there has been proposed a fan coupling in which a storage chamber is integrally supported by a base member which does not always rotate, as disclosed in Japanese Patent Publication No. 1-59450. However, in the case of this fan coupling, the viscous fluid is supplied to the working chamber while the opening area of the inflow side thin tube provided in the storage chamber is kept constant so as to return the viscous fluid from the working chamber (the space where the rotor exists). In order to control the torque transmission ratio by adjusting the opening area of the small tube on the outflow side with a valve device in order to
There is a problem that the response of the flow rate adjustment is poor.

Accordingly, the present invention is to provide a fan coupling which can control the torque transmission ratio with high accuracy and with good responsiveness.

[0007]

According to the present invention, as a means for solving the above-mentioned problems, a drive shaft rotatably supported by a base member, a housing rotatably supported by the drive shaft, and A rotor housed in the housing and integrally supported by the drive shaft, a storage chamber integrally supported by the base member and storing a viscous fluid in the housing, and housed in the storage chamber so as to be able to move forward and backward; That
A piston for adjusting the amount of viscous fluid supplied to the gap between the housing and the rotor by changing the substantial storage volume of the storage chamber by the reciprocating operation, and passing through the gap between the housing and the rotor;
A return passage for returning the viscous fluid to the storage chamber;
The tongue projects at a position facing the end of the return passage,
A projection that narrows the return passage by the forward movement of the piston,
Was prepared.

[0008]

Since the storage chamber is integrally supported by the base member, the viscous fluid in the storage chamber does not flow even when the rotor or the housing rotates. Also, when the substantial storage volume of the storage chamber is changed by the reciprocating operation of the piston, the viscous fluid exceeding the substantial storage volume overflows from the storage chamber and is supplied to the gap between the housing and the rotor. become. Also, Hauge
Pin to increase the amount of viscous fluid supplied to the gap between the rotor and the rotor.
When the ston moves forward, the protrusion protruding from the piston returns
Restrict the passage to determine the amount of outflow and return of viscous fluid from the storage chamber.
The difference is adjusted to be small.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In the drawings , reference numeral 1 denotes a drive shaft integrally formed with a pulley 2. The drive shaft 1 is formed in a cylindrical shape, and its inner peripheral side is provided with a base member 4 through a bearing 3.
It is supported rotatably. The base of the base member 4 is connected and supported by an engine block, a water pump body, and the like (not shown). Reference numeral 5 denotes a housing in which a viscous fluid is sealed. The housing 5 is rotatably supported on the drive shaft 1 via a bearing 6 and has a fan blade (not shown) mounted on an outer peripheral portion thereof. And a cover 8 fitted and fixed to the front surface thereof.

A rotor 9 is integrally connected to the outer periphery of the distal end of the drive shaft 1. The rotor 9 is rotatably disposed inside the housing 5.
Is formed along the radial direction on the peripheral edge portion of the cover 8 and the wall surface of the cover 8 opposed to the peripheral portion, and the labyrinth groove 10 is formed by the mutual unevenness. In this fan coupling, by supplying a viscous fluid to the labyrinth groove 10 from the inner diameter side of the housing 5, the torque of the rotor 9 is transmitted to the housing 5 using the viscous fluid as a power transmission medium. On the other hand, near the outer peripheral portion of the cover 8, a return passage 11 for returning the viscous fluid that has reached the outer diameter side of the housing 5 to the inner diameter side again is formed.

The tip of the base member 4 penetrates through the inside of the cylindrical drive shaft 1 and is located inside the housing 5. The tip stores a viscous fluid in the housing 5. The storage chamber 12 is connected and supported. This storage chamber 12 is a casing 1 formed in a cylindrical shape with a bottom.
3 and a lid 14 connected to an end face of the casing 13.
The casing 13 includes the storage chamber 1
2 to change the actual storage volume in the space
A piston 15 is housed therein, and a communication hole 16 is formed in the center of the lid 14. The piston 15 has a base member 4
The base of the rod 17 that penetrates the base member 4 is integrally connected, and the tip of the rod 17 is supported on the end face of the base member 4 via the return spring 18. Therefore, the piston 1
5 is constantly urged toward the bottom of the storage chamber 12 by the return spring 18. A boss 19 is formed at the inner end of the return passage 11.
Numeral 9 is loosely inserted into the communication hole 16, and its tip protrudes into the storage chamber 12. The communication hole 16 serves to introduce the viscous fluid returned to the inner diameter side of the housing 5 through the return passage 11 into the storage chamber 12, and overflows the viscous fluid from the storage chamber 12 to the labyrinth groove 10. Serves to supply. Furthermore, at the center position of the front surface of the piston 15,
A columnar or tapered projection 30 is located at the tip of the boss 19.
It is formed so as to face the end of the return passage 11 at the end.
When the piston 15 moves forward, the projection 30 returns
It is designed to be loosely inserted into the road 11. In addition, 20 is
A discharge hole is provided to allow air to enter and exit, and to discharge the viscous fluid leaking to the rear side (right side in the drawing) of the piston 15 to the outside of the storage chamber 12, 21 is a seal ring, and 22 is fixed to the rod 17. This is a flange for supporting the return spring 18.

Reference numeral 23 denotes a step motor mounted on the base of the base member 4. An eccentric cam 24 for moving the rod 17 forward and backward is mounted on the shaft of the step motor 23.
Are combined. The step motor 23 is electrically connected to a control device 25 for controlling the rotation of the step motor 23. The control device 25 includes a radiator water temperature detecting device 2
6. Air conditioner refrigerant temperature detecting device 27, vehicle speed detecting device 2
8. The engine speed detector 29 and the like are electrically connected.

With the above configuration, when a detection signal is sent from the radiator water temperature detecting device 26, the air conditioner refrigerant temperature detecting device 27, the vehicle speed detecting device 28, the engine speed detecting device 29, etc. to the control device 25, the control is performed. The device 25 sends an angle command signal most suitable for the current operation state to the step motor 23. Based on this signal, the step motor 23
Rotate, the rod 17 and the piston 15 advance and retreat in conjunction with this, the volume of the front side (left side in the figure) of the storage chamber 12 changes, and the viscous fluid overflowing from the storage chamber 12 through the communication hole 16. , That is, the amount of the viscous fluid supplied to the labyrinth groove 10 is adjusted.

The viscosity supplied to the labyrinth groove 10
Piston 15 moves forward when increasing the amount of fluid
And the protrusion 30 is gradually inserted into the end of the return passage 11,
The end of the return passage 11 is narrowed to prevent the flow of the viscous fluid.
I can do it. For this reason, it is stored by the advance of the piston 15.
Even if the outflow of the viscous fluid from the chamber 12 increases,
The amount of viscous fluid entering the inner diameter side of
Viscous fluid returned to the return passage 11 from the outer diameter side of the groove 10
Large differences in the amount of This results in an increase in viscous fluid
The rotation disturbance of the housing 5 caused by the
The response of the rotation control of the ring 5 is improved.

That is, if there is no protrusion 30,
The piston 15 moves forward and the viscous fluid flows from the storage chamber 12.
When the output increases, the rotor 9 and the housing 5 initially increase.
Labyrinth so that the relative rotation of
Compared to the amount of viscous fluid that actually enters the inside of the groove 10
Returned to passage 11 back from the outer diameter side of the labyrinth groove 10 Te
The amount of viscous fluid increases. Because of this, an increase in viscous fluid
Initially, storage chamber 12, labyrinth groove 10, return passage 1
1. The flow of the viscous fluid circulating with the storage chamber 12 is low for a while.
The rotation of the housing 5 is disturbed,
In the fan coupling according to the invention, the piston
With the forward movement of No. 15, the protrusion 30 is determined by
Such a problem occurs because the difference in return amount is small.
Absent.

When the supply amount of the viscous fluid to the labyrinth groove 10 is adjusted as described above, the torque transmission ratio from the rotor 9 to the housing 5 is adjusted accordingly,
An appropriate air volume can be obtained by the fan.

Further , in this fan coupling, since the storage chamber 12 is integrally connected to and supported by the base member 4, the storage chamber 12 itself does not rotate even when the rotor 9 and the housing 5 rotate. Therefore, for example, when the operation is started from a state in which the operation is temporarily stopped, the viscous fluid flows through the storage chamber 12 even though the viscous fluid in the housing 5 is mostly stored in the storage chamber 12. No longer. As a result, the supply amount of the viscous fluid does not vary due to the flow of the viscous fluid in the storage chamber 12.

[0019]

[Effect of the invention] As described above, the present invention is based on a storage room.
The viscous fluid in the storage chamber always flows by being integrally supported by the member
The gap between the rotor and the housing.
Supply of the desired amount of viscous fluid to the
In addition, the actual storage of the storage chamber is
Change the remaining volume and fix the piston when the piston moves forward.
Adjust the throttle amount of the return passage with the protrusion protruding from the
Therefore, when the torque transmission ratio is switched,
Reduce the difference between the outflow amount and return amount of the viscous fluid
Rotation disturbance can be reduced. Therefore,
According to the present invention, a desired target can be obtained with high accuracy and high responsiveness .
It is possible to control the torque transmission ratio .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... drive shaft, 4 ... base member, 5 ... housing, 9 ... rotor, 11 ... return passage, 12 ... storage chamber, 15 ... piston , 30 ... protrusion.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Makoto Kawada 1370 Onna, Atsugi-shi, Kanagawa Prefecture Inside Atsugi Unisia Corporation (72) Inventor Hidetoshi Shima 1370 Onna, Atsugi-shi, Kanagawa Prefecture Inside Atsugi Unisia Corporation (72 ) Inventor Yasushi Hiyama 1370 Onna, Atsugi City, Kanagawa Prefecture Inside Atsugi Unisia Co., Ltd. (56) References JP-A-60-164615 (JP, A) JP-A-58-77120 (JP, U) 59450 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) F16D 35/02

Claims (1)

(57) [Scope of request for utility model registration] A drive shaft rotatably supported by the base member; a housing rotatably supported by the drive shaft;
A rotor which is supported integrally with the drive shaft while being furnished to the housing, a reservoir chamber for storing a viscous fluid within the housing is supported integrally with the base member, are retractably housed in the storage chamber , In its movement
Piston to adjust the amount of viscous fluid supplied into the gap of the housing and the rotor by changing the substantial storage capacity of more reservoir
And viscous flow through the gap between the housing and rotor
A return passage for returning a body to the storage chamber;
The piston is provided at a position facing the end of the
And a projection for narrowing the return passage by the forward movement of the fan.