JP2525783Y2 - Fan coupling - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature sensing type fan coupling used for a cooling fan drive of an internal combustion engine for an automobile.

2. Description of the Related Art A cooling fan installed in an internal combustion engine for a vehicle employs a temperature sensing type fan coupling that senses an ambient temperature behind a radiator and controls a fan rotation speed to a value suitable for the temperature. is there.

FIG. 2 shows an example of the fan coupling used here.

In this fan coupling, a housing 1 to which a fan blade (not shown) is attached is mounted on a drive shaft 2 via a bearing 3, and a rotor 4 is fixed to the tip of the drive shaft 2 inside the housing 1. Have been. The housing 1 includes a housing main body 5 supported by the drive shaft 2 and a cover 6 fitted and fixed to the front surface thereof.
A partition plate 9 for partitioning the inside of the housing 1 into a storage chamber 7 and a working chamber 8 is fixed inside the housing 1. Irregularities are formed in the radial direction on the peripheral portion of the rotor 4 and the wall surface of the cover 6 opposed thereto, and a labyrinth groove 10 is formed by the concave and convex portions. A high-viscosity working fluid such as silicone oil is stored in the storage chamber 7, and the partition plate 9 is provided with an outflow hole 11 for supplying the working fluid from the storage chamber 7 to the working chamber 8. A return passage near the outer peripheral portion of the cover 6 for returning the working fluid from the working chamber 8 to the storage chamber 7 in reverse.
12 are formed. A rotary shaft 13 is supported at the center of the cover 6, and a spiral bimetal 14 having one end fixed to the cover 6 is connected to a distal end of the rotary shaft 13, and a proximal end is connected to a proximal end. Outflow hole 11 inside the storage chamber 7
The valve plate 15 that opens and closes is rigidly connected. The outflow hole 11 is simply formed in a direction perpendicular to the partition plate 9.
The opening areas on the sides are almost the same.

The fan coupling controls the number of revolutions in accordance with the change in the ambient temperature as follows.

When the ambient temperature behind the radiator (not shown) is low, the bimetal 14 does not deform and the valve plate 15 closes the outflow hole 11. Therefore, the viscous fluid is not supplied from the storage chamber 7 to the working chamber 8. Therefore, the amount of the viscous fluid existing in the labyrinth groove 10 is small, and the torque transmitted from the rotor 4 to the housing 1 is small. As a result, the rotation speed of the housing 1, that is, the fan blade (not shown), becomes lower.

On the other hand, when the ambient temperature behind the radiator (not shown) increases, the rotating shaft 13 rotates with the extension deformation of the bimetal 14, and the valve plate 15 slides in the circumferential direction to open the outflow hole 11. . Then, the viscous fluid flows into the working chamber 8 and returns from the labyrinth groove 10 through the return passage 12. Therefore, the viscous fluid is sufficiently supplied to the labyrinth groove 10, the torque transmitted from the rotor 4 to the housing 1 increases, and the rotation speed of the housing 1, that is, the fan blade (not shown) increases (similar technology). Is, for example,
-204491).

However, in the case of the conventional fan coupling described above,
Due to the high viscosity of the working fluid, when the working fluid passes through the outflow hole 11, it receives a large resistance from the inner surface A of the outflow hole 11 and the opening edge B on the working chamber 8 side as shown in FIG. As a result, a turbulent flow occurs in the peripheral area of the end of the outflow hole 11 on the working chamber side. For this reason, when the outflow hole 11 is opened, the working fluid hardly passes through the outflow hole 11, which causes a problem that the response of the rotation of the housing 1 to a change in the bimetal 14 (a change in the ambient temperature) is delayed.

On the other hand, the outflow hole is formed in a tapered shape so that the opening area on the working chamber side is increased, and as much as possible the resistance received from the inner surface or the opening edge on the working chamber side when the working fluid passes through the outflow hole. Although a technique for reducing the number of holes has been proposed, it is difficult to accurately process the outflow hole into a tapered shape, which tends to increase the manufacturing cost.

Therefore, the present invention does not increase the manufacturing cost,
It is an object of the present invention to provide a fan coupling capable of improving the responsiveness of air flow control to a change in ambient temperature.

Means for Solving the Problems As means for solving the above-described problems, a partition plate for partitioning the inside into a storage chamber and a working chamber is provided in the housing, and an outflow hole for working fluid is provided in the partition plate, In a fan coupling in which an outlet hole is opened and closed by a valve body linked to an ambient temperature change behind the radiator, a thin auxiliary member is attached to a surface of the partition plate on the storage chamber side, and a first through hole is formed in the auxiliary member. And the first plate is attached to the partition plate.
A second through-hole communicating with the through-hole and having a larger opening area than the first through-hole is formed, and the first through-hole and the second through-hole allow the working chamber side to have a larger opening area than the storage chamber side. A hole is formed.

When the ambient temperature behind the radiator rises and the valve element opens the outlet, the working fluid in the storage chamber flows into the working chamber through the outlet. (2) Since the opening area of the through hole is set to be larger than the opening area of the first through hole on the storage chamber side, when the working fluid passes through the outflow hole, the opening area of the outflow hole or the opening edge on the working chamber side is reduced. This reduces the resistance that occurs and prevents turbulence in the peripheral area of the end of the outflow hole on the working chamber side.

Embodiment An embodiment of the present invention will be described below with reference to FIG.
The same parts as those shown in FIGS. 2 and 3 are denoted by the same reference numerals, and the description of the overlapping parts will be partially omitted.

In FIG. 1, the fan coupling is such that a housing 1 is supported on a drive shaft 2 via a bearing 3, and the interior of the housing 1 is partitioned into a storage chamber 7 and a working chamber 8 by a partition plate 9. The labyrinth groove is formed by the point at which the rotor 4 is coupled to the tip of the drive shaft 2 inside the rotor 8 and the peripheral edge of the rotor 4 and the wall surface of the cover 6 facing the rotor 4
At the point where 10 is formed, outflow holes 11a and 11b are provided in the partition plate 9, while a return passage 12 is provided near the outer peripheral portion of the cover 6, and the outflow holes 11a and 11b are slid and opened and closed by the valve plate 15. The basic configuration that the rotating shaft 13 is supported at the center of the cover 6 and a bimetal 14 as a temperature sensing member is connected to the rotating shaft 13 is the same as the conventional configuration shown in FIGS. It is almost the same as the one. In the case of the fan coupling shown in FIGS. 2 and 3, only one outflow hole 11 is formed in the partition plate 9, whereas in this embodiment, the outflow hole 11 radially outside the partition plate 9 is formed. In addition to the hole 11a, another outflow hole 11b is formed radially inward. This inner outflow hole 11b is set to open at a temperature lower than the temperature at which the outer outflow hole 11a opens, and when the ambient temperature gradually increases, first, the small size of the valve plate 15 The outflow hole 11b is opened by the rotation of the angle, and then the outflow hole is opened by the large angle rotation of the valve plate 15 as the second stage.
11a opens.

In the case of the fan coupling according to the present invention, the structure of the outflow holes 11a and 11b provided in the partition plate 9 is significantly different from that shown in FIGS.

That is, in the case of this fan coupling, a thin auxiliary member 16 is provided on the surface of the partition plate 9 on the storage chamber 7 side, and the first through hole 20 formed in the auxiliary member 16 and the partition plate 9 are directly connected to the auxiliary member 16. Outflow holes 11a and 11b are respectively formed by the drilled second through holes 21. Then, the first through hole 20 and the second through hole 21
And the opening area of the second through-hole 21 is larger than the opening area of the first through-hole 20. In addition, the partition plate 9
The periphery of the end portion of the second through hole 20 formed on the working chamber 8 side may be rounded by pressing.

As described above, the fan coupling according to the present invention is
Since the opening area of the outflow holes 11a and 11b on the working chamber 8 side is set to be larger than the opening area of the storage chamber 7, the ambient temperature behind the radiator rises and the outflow holes 11a and 11b are opened by the valve plate 15. If the working fluid flows out
When passing through b, the resistance received from the inner surface and the opening edge on the working chamber 8 side is reduced, and the flow velocity on the lower layer side is less likely to decrease. As a result, turbulence does not occur in the peripheral area of the end of the outflow holes 11a and 11b on the side of the working chamber 8, and even when the outflow holes 11a and 11b are opened, the working fluid smoothly flows from the storage chamber 7 to the working chamber 8 To flow to. As a result, the response of the rotation of the housing 1 to a change in the ambient temperature behind the radiator is improved.

Further, in the case of this fan coupling, the first through hole 20 and the second through hole 21 having different opening areas are formed in the thin auxiliary member 16 and the partition plate 9 themselves, respectively, so that the outflow holes 11a and 11b are formed. Since the opening area on the working chamber 8 side is set to be larger than the opening area on the storage chamber 7 side, the outflow holes 11a and 11b having the above-described functions can be formed very easily, and therefore, the cost can be reduced. Can be manufactured.

Effect of the Invention As described above, according to the present invention, a thin auxiliary member is attached to the surface of the partition plate on the storage chamber side, and a first through hole is formed in the auxiliary member. A second through-hole communicating with the through-hole and having a larger opening area than the first through-hole is formed, and the first through-hole and the second through-hole allow the working chamber side to have a larger opening area than the storage chamber side. Since the holes are formed, it is possible to prevent the occurrence of turbulent flow in the peripheral region of the end of the outflow hole on the working chamber side, thereby stabilizing the outflow of the working fluid from the storage chamber to the working chamber, and Outflow holes can be machined very easily. Therefore, it is possible to improve the responsiveness of the air volume control to the change in the ambient temperature without increasing the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view showing a conventional technique, and FIG. 3 is a large sectional view showing a main part of the technique. DESCRIPTION OF SYMBOLS 1 ... Housing, 7 ... Storage chamber, 8 ... Working chamber, 9 ... Partition plate, 11a, 11b ... Outflow hole, 15 ... Valve plate (valve element), 1
6 ... Auxiliary member, 20 ... First through hole, 21 ... Second through hole.

Claims (1)

(57) [Scope of request for utility model registration] A housing is provided with a partition plate for partitioning the interior into a storage chamber and a working chamber, and an outflow hole for a working fluid is provided in the partition plate, and the outflow hole is linked to a change in ambient temperature behind the radiator. In a fan coupling that is opened and closed by a body, a thin auxiliary member is attached to a surface of the partition plate on the storage chamber side, a first through hole is formed in the auxiliary member, and a first through hole is formed in the partition plate. And a second through-hole having a larger opening area than the first through-hole is formed.
A fan coupling characterized in that an outflow hole having a larger opening area on the working chamber side than on the storage chamber side is formed by the through hole and the second through hole.