JPH0353053Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a temperature-sensitive type cooling fan that is mainly applied to internal combustion engines for vehicles and has a function to automatically control the operation of the cooling fan according to the ambient temperature conditions. This invention relates to improvements in fluid type fan coupling devices.

(Prior Art) This type of temperature-sensitive fluid type fan coupling device is described in, for example, Japanese Utility Model Application Publication No. 61-49138, and its typical structure is as shown in FIG. 5 of the accompanying drawing. A sealed case 6 is supported for relative rotation on a rotary drive shaft 1 to which a drive disk (wheel) 2 is fixed via a bearing 3, and the inside of the sealed case is divided into an oil reservoir chamber 8 and a torque transmission chamber 9 by a partition plate 7.
It is divided into. A sealed case 6 having a cooling fan (not shown) attached to its outer periphery is assembled with a cover 4 and a body 5 holding a bearing 3. A temperature sensing element 10 made of a bimetal and disposed outside the cover 4 side of the sealed case is bent and deformed in response to temperature changes, and a valve member 12 is provided on the partition plate 7 to contact the piston rod 11 in conjunction with this. The outflow adjustment hole 13 is opened and closed, and oil flows from the oil reservoir chamber 8 to the torque transmission chamber 9, thereby transmitting torque. Furthermore, as another conventional example, Tokkosho
As shown in Publication No. 55-616, a structure in which a spiral bimetal or the like is used as a temperature sensor, and the outflow adjustment hole is opened and closed by sliding the valve member in the left and right directions in response to temperature changes. There is also.

The cover 4 and body 5 of the sealed case 6 have cooling fins 31 and 32 on their outer surfaces, respectively, which are integrally molded by die-casting from aluminum and protrude from the outer surface of the sealed case. It suppresses the rise in oil temperature.

However, in both conventional examples, since the fins 31 and 32 have a solid structure as shown in FIG. 6, the heat conduction for cooling the silicone oil inside is poor, and the ability to cool the fan coupling spring and dissipate heat is poor. It wasn't enough. As a result, as the outside temperature rises, the silicone oil becomes hotter, its viscosity decreases, and the transmitted torque decreases. For this reason, it is necessary to adopt a large fan coupling device with a large torque that has a considerable margin of torque than the design-required transmission torque, resulting in an increase in space, an increase in fan noise, and a decrease in efficiency. There were problems such as rising costs.

(Problems to be solved by the invention) The purpose of the invention is to increase the heat dissipation cooling effect of the fins, thereby suppressing the rise in temperature of silicone oil and preventing a decrease in viscosity, and by suppressing variations in transmission torque. To provide a fan coupling device capable of reducing the size of a coupling and reducing noise.

Another object of the present invention is to provide a fan coupling device that can improve the durability of various heat-resistant parts by increasing the cooling effect of the entire fan coupling.

(Means for Solving the Problems and Their Effects) The above-mentioned purpose of the present invention is to provide a general temperature-sensitive fluid type fan coupling device in which a large number of fins are protruded from the outer surface of the sealed case. The fins are integrally molded with the sealed case and have a hollow portion in which oil flows, and the fins are connected to each other by a fan coupling device connected by a thin plate-like heat dissipating piece.

Based on this configuration, according to the present invention, oil such as silicone oil penetrates into the cavity inside the fin and circulates, so that the heat conduction length is shortened and the heat transfer efficiency is increased. In addition, since the fins are connected to each other by the thin heat dissipating pieces, heat transfer is further promoted and the hollow fins are structurally reinforced. Due to the heat dissipation from the fins and heat dissipation piece, the amount of heat dissipated from the outer surface of the sealed case (exchanged heat amount) increases, increasing the cooling efficiency of the sealed case and the fan coupling spring as a whole, and lowering the temperature of silicone oil and various heat-resistant parts. . As a result, the viscosity of the silicone oil is prevented from decreasing, so variations in transmission torque and rotation speed are reduced, and sudden fan noise is also prevented from occurring. Therefore, extra torque is not required, and the fan coupling device can be made smaller. In addition, the durability of the heat-resistant parts will be improved.

The shape of the fins can be formed into a rib shape extending radially from the rotational drive axis or a substantially cylindrical shape that projects. The heat dissipating piece can be formed into a shape that bridges between fins in a single layer or in multiple layers.

Other features and advantages of the invention will become apparent from the following description with reference to the embodiments shown in the accompanying drawings, FIGS. 1-4.

(Example) Figures 1 and 2 show a longitudinal section and a front view of the cover side of a temperature-sensitive fluid type fan coupling device according to a preferred embodiment of the present invention. The illustration of the cooling fan is omitted.

In FIG. 2A, a large number of fins 21 are arranged on the outer surface of the cover 4 in the form of ribs extending radially from the rotational drive axis. Adjacent fins 21 are connected to each other by a thin heat radiation piece 22, and a ventilation louver 23 is provided between the heat radiation pieces. The cross section of the fin 21 is as shown in FIG.
The interior of the protruding outer wall forms a cavity 24 adapted to receive oil. Therefore, the high temperature silicone oil circulates through the cavity 24 and is efficiently cooled. The heat dissipating pieces 22 enhance the cooling effect and support and reinforce the fins 21. Louver 2
3 serves to reduce the thickness of the boundary layer on the surface of the heat sink 22, improve the heat transfer coefficient from the surface of the heat sink to the air, and guide external low temperature air to the high temperature sealed case surface. Furthermore, the fins 2 of the heat dissipation piece 22
There is a bur ring (flange) 25 on the contact part with 1.
is provided to increase the contact area and increase the heat transfer rate to the heat dissipation piece.

In FIG. 2B, a large number of fins 26 provided on the outer surface of the cover 4 are arranged in a staggered manner in a substantially cylindrical shape. Adjacent fins 26 are connected to each other by a thin heat radiation piece 27, and a ventilation louver 28 is provided between the heat radiation pieces. The cross section of the fin 26 is as shown in FIG.
The interior of the protruding outer wall forms a cavity 29 adapted to receive oil. Therefore, the high temperature silicone oil circulates through the cavity 29 and is efficiently cooled. In this example, the heat dissipation pieces 27A, 2
7B is arranged in two layers, and the upper layer heat dissipation piece 2
A louver 28 is formed on 7A, and the lower layer heat dissipation piece 2
Only the opening 30 is drilled in 7B. The heat dissipation pieces can also be arranged in multiple layers depending on the dimensions of the fins and the amount of heat dissipation.

Since the apparatus according to the embodiment of the present invention is constructed as described above, the silicone oil is sufficiently cooled and a decrease in viscosity is prevented. At the same time, by efficiently cooling the entire fan coupling spring, the heat load on parts that require heat resistance, such as seals, adhesives, and lubricants, located inside the device is reduced.

In the above embodiment, only the structure of the fins on the cover 4 side has been described, but the present invention can also be applied to the fins on the body 5 side.

(Effects of the invention) As explained in detail above, according to the present invention, the above-mentioned effects can be obtained, and in particular, stabilization of the temperature of silicone oil, stabilization of transmission torque, miniaturization of the fan coupling spring, Its practical value is remarkable, such as reducing noise and improving the durability of heat-resistant parts.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway longitudinal sectional view showing a fan coupling device according to an embodiment of the present invention, and a sectional view taken along the line - in Fig. 2, and Fig. 2 shows two embodiments of the device as seen from the cover side. A front view showing A and B, FIG. 3 is a sectional view of the fin along the line - in FIG. 2,
FIG. 4 is a sectional view of the fin along the line - in FIG. 2, and FIG. 5 is a partially cutaway vertical sectional view of the conventional device.
FIG. 6 is a cross-sectional view of the fin along line - in FIG. 5. 1... Drive shaft, 2... Drive disk, 4... Cover, 5... Body, 6... Sealed case, 7...
Partition plate, 8... Oil reservoir chamber, 9... Torque transmission chamber,
10... Temperature sensitive body, 11... Piston rod, 12...
Valve member, 13... outflow adjustment hole, 21, 26... fin, 22, 27... heat radiation piece, 23, 28... louver, 24, 29... hollow portion, 25... bur ring.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A sealed case that is relatively rotatably supported on a rotary drive shaft with a drive disk fixed to the tip and a cooling fan attached to the outer periphery, and the inside of this sealed case is connected to an oil reservoir and a torque chamber. A partition plate partitioning the oil into a transmission chamber and having an oil outflow adjustment hole, a valve member for opening and closing the outflow adjustment hole, and a bimetallic temperature sensing element disposed outside the sealed case. In a temperature-sensitive fluid type fan coupling device in which a valve member opens and closes an outflow adjustment hole in conjunction with the deformation of a hot body, a large number of fins are protruded from the outer surface of the sealed case, and each fin is attached to the sealed case. 1. A temperature-sensitive fluid type fan coupling device, characterized in that the fins are integrally molded and have a hollow portion through which oil flows, and the fins are connected to each other by a thin plate-like heat dissipating piece. 2. The device according to claim 1, wherein the fins are arranged in a rib shape extending radially from the rotational drive axis. 3. The device according to claim 1, wherein the fins are formed into a substantially cylindrical projecting shape, and the heat dissipating pieces are arranged in two or more layers between the fins. 4. The device according to claim 1, wherein a burring is formed at the contact portion of the heat dissipating piece with the fin to increase the contact area. 5. The device according to claim 1, wherein a louver is formed on the heat dissipation piece.