JP2552013Y2 - Engine sub-tank structure - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine sub-tank structure, and more particularly, to an engine sub-tank structure which can be positioned relatively downward.

[0002]

2. Description of the Related Art A water-cooled cooling device for an engine is known which has a closed cooling water circuit including a radiator. In such a cooling device, cooling water as a heat medium is circulated through a cooling water circuit, and heat generated by the engine is radiated by a radiator. Generally, since the cooling water of the engine reaches a considerably high temperature, bubbles are mixed into the cooling water due to cavitation action, vibration of the cylinder block, and the like.

[0003] In order to reliably perform air bubble separation or air / water separation, there is known a down flow type radiator in which a sub-tank having a water / water separation function is connected to an upper tank (Japanese Patent Laid-Open No. 62-191612; Showa 60-577
No. 36). In addition, a cooling device having a cross-flow radiator has been proposed in which such a subtank is connected to an upstream tank and / or a downstream tank of the radiator (Japanese Patent Application No. 3-249 filed by the present applicant).
No. 756 (filed on September 27, 1991).

[0004] Such a sub-tank must be located at a position where bubbles contained in the cooling water are separated from the cooling water to increase the cooling efficiency of the cooling device and that sufficient cooling water can be supplied to the cooling water circuit. . For this reason, in the cooling device described in Japanese Patent Application Laid-Open No. 62-191612, the liquid level of the sub tank is positioned higher than the liquid level of the water jacket of the engine.

[0005]

However, in recent vehicle body designs, there is a tendency that the height of the hood is designed to be low, and the allowable height of the device installation space in the engine room is set relatively low. For this reason, if a vehicle body design that emphasizes the outer shape of the vehicle body is adopted, the sub-tank cannot be installed at a desired height. On the other hand, if the height of the sub-tank is secured, the desired vehicle outer shape cannot be achieved.

The present invention has been made in view of the above point, and an object of the present invention is to provide a sub-tank structure of an engine which can be positioned relatively downward, thereby enabling a low bonnet of a vehicle body. As well as ensuring a desired arrangement of the sub-tank.

[0007]

In order to achieve the above object, the present invention has a sub-tank connected to a cooling water circuit of an engine, wherein the sub-tank has a water / water separator for separating water / water of cooling water. In a sub-tank structure of an engine having a space and an expansion space for compensating for a change in volume of cooling water and air in the air-water separation space, the sub-tank is separated from the separation chamber constituting the air-water separation space and the separation chamber. An expansion chamber forming the expansion space, and communication means for mutually communicating the expansion chamber and the separation chamber, wherein the expansion chamber is disposed below the separation chamber. To provide a sub-tank structure of the engine.

[0008]

According to the above construction of the present invention, the expansion space for compensating the pressure fluctuation of the cooling water and air in the separation chamber is formed by the expansion chamber disposed below the separation chamber. Therefore, the expansion space formed above the cooling water can be reduced, and the upper end of the sub tank can be set low. Preferably, the sub
The tank is made of resin and has the above separation chamber and expansion chamber.
A molding tank, wherein the sub-tank comprises a separation chamber, an expansion chamber,
And a partition for partitioning or isolating.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of a cooling device for an engine having a sub-tank structure according to the present invention. The engine 10 includes a cooling device 12. Cooling device 12
Is a water jacket of the engine 10 (not shown)
A radiator 14 for cooling the high-temperature cooling water flowing out of the
A thermostat 18 for bypassing the cooling water flowing toward the radiator 14 and a water pump 16 for forcibly circulating the cooling water are provided.

The radiator 14 includes an upstream tank 20 into which the cooling water flows, and a radiator core 22 for cooling the cooling water.
And a downstream tank 24 for receiving the cooling water passing through the radiator core 22. The radiator core 22
The cooling water is cooled by a heat exchange action between the cooling water and a traveling wind or a blowing air formed by a cooling fan (not shown).

A cooling water inflow pipe 26 is disposed between the upstream tank 20 and the water jacket of the engine 10.
A cooling water recirculation pipe 28 is disposed between the downstream tank 24 and the water pump 16, and further, a cooling water inflow pipe 26 is provided.
A bypass pipe 30 is arranged between the cooling water recirculation pipe 28 and the cooling water recirculation pipe 28. The thermostat 18 is provided at the connection between the cooling water recirculation pipe 28 and the bypass pipe 30, and determines the amount of cooling water (indicated by an arrow a) flowing into the upstream tank 20 and the radiator 14.
To adjust the amount of cooling water (indicated by an arrow b) flowing back to the engine 10 by bypassing the cooling water temperature.

The cooling device 12 also has a sub-tank 40 for separating water and water. The sub-tank 40 includes a separation chamber 42
, An expansion chamber 44 disposed below the separation chamber 42, and a communication pipe 46 that allows the separation chamber 42 and the expansion chamber 44 to communicate with each other. An air passage 48 is connected to the separation chamber 42,
The air passage 48 is connected to the branch passages 32, 3 via the switching valve 36.
4. The branch passage 32 is connected to the upstream tank 20.
The branch passage 34 is connected to the downstream tank 24, and the switching valve 38 selectively communicates the air passage 48 with the branch passage 32 and / or the branch passage 34 according to the operating state of the engine 16. Let it. The return pipe 38 is in the separation chamber 4
2 and the return pipe 38 is connected to the thermostat 18.
At the downstream side of the cooling water recirculation pipe 28.

FIG. 2 shows a sub-tank 40 disposed on a vehicle.
FIG. 3 is a longitudinal sectional view showing the structure of the sub tank 40.
FIG. The sub-tank 40 is arranged in an engine room of the vehicle, and is located below a hood 60 (shown by a virtual line) of the vehicle. The sub tank 40 is a resin tank integrally formed so as to form the separation chamber 42 and the expansion chamber 44, and the separation chamber 42 and the expansion chamber 44 are separated by a partition 43. A plurality of brackets 40a are provided below the sub-tank 40, and the sub-tank 40 is supported by a vehicle body (not shown) by the brackets 40a.

The separation chamber 42 is disposed above the water jacket of the engine 10, and includes a top wall 42a and a side wall 4a.
2b and the partition 43. Top wall 42a
Is formed with a substantially cylindrical protrusion 52, and a lower end of the protrusion 52 communicates with the separation chamber 42. A cap 54 is attached to the upper end of the protrusion 52, and the separation chamber 42 and the protrusion 52
Constitutes a continuous closed space. An inflow pipe 56 is provided adjacent to the protruding portion 52, and the inflow pipe 56 protrudes upward from the top wall 42a and is bent forward of the vehicle body.
The inflow pipe 56 is provided with the air passage 48 made of a flexible pipe.
Are connected. The outflow pipe 58 is connected to the side wall 42b, and the outflow pipe 58 projects rearward from the side wall 42b and is bent downward. The return pipe 38 communicating with the water pump 16 of the engine 10 is connected to the outflow pipe 58.

The expansion chamber 44 is disposed below the separation chamber 42, and forms a sealed space defined by a partition 43, a bottom wall 44a, and a side wall 44b. Also, the bottom wall 44a
A step portion 44c for forming a liquid reservoir is provided. The protrusion 5
A communication port 52a is formed on a side surface of the communication port 2, and an upper end of the communication pipe 46 is connected to the communication port 52a. Communication pipe 46
Extends substantially vertically downward, and the lower end of the communication pipe 46 is connected to the lower end portion of the side wall 44b of the expansion chamber 44, that is, the portion of the side wall 44b forming the liquid reservoir.
Thus, the upper end of the separation chamber 42 and the lower end of the expansion chamber 44 communicate with each other via the communication pipe 46.

As shown in FIG. 2, the liquid level of the cooling water in the separation chamber 42 is always located at the liquid level WL between the highest liquid level HL and the lowest liquid level LL. Cooling water containing air bubbles or air is supplied from the radiator 14 to the air passage 48 and the inflow pipe 56.
Flows into the separation chamber 42 through The cooling water from which bubbles or air have been separated in the separation chamber 42 is returned to the engine 10 through the outflow pipe 58 and the return pipe 38.

When the temperature of the cooling water rises and the liquid level WL of the cooling water in the separation chamber 42 rises, or when excess air accumulates in the separation chamber 42, the air above the liquid level WL is removed by the expansion chamber 44.
The gas flows out from the communication pipe 46 into the expansion chamber 44 while increasing the gas pressure therein. Further, when the temperature of the cooling water drops and the liquid level WL of the cooling water in the separation chamber 42 drops, or the air pressure in the separation chamber 42 decreases, the air in the expansion chamber 44 having a relatively high pressure flows into the communication pipe 46. To the separation chamber 42. Thus,
The expansion chamber 44 functions as a means for compensating for a change in volume of the cooling water and air in the separation chamber 42, and ensures a smooth water-water separation action of the cooling water in the separation chamber 42.

As described above, the sub-tank 40 connected to the engine 10 and the radiator 14 includes the separation chamber 42 for separating water and water of the cooling water, the communication pipe 46 connected to the top of the separation chamber 42 and extending downward, An expansion chamber 44 is provided below the separation chamber 42 and communicates with a lower end portion of the communication pipe 42. According to the sub-tank 40 having such a configuration, the sub-tank can be designed without securing an expansion space above the cooling water for compensating pressure fluctuations of the cooling water and the air in the separation chamber 42, so that the upper end of the sub-tank is set low. it can. Therefore, in a vehicle in which the effective height of the engine room is limited, for example, a so-called low bonnet type vehicle, the sub tank can be easily installed in the engine room. In other words, according to the structure of the sub tank 40, the degree of freedom in designing the vehicle body can be improved.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various changes or modifications can be made, and these are also described in the claims for utility model registration. It goes without saying that the present invention is included within the scope of the present invention. For example, in the above embodiment, the separation chamber and the expansion chamber are formed by the integrally formed sub-tank, but the separation chamber and the expansion chamber are respectively formed by the separately formed tanks, and the two tanks are connected by a communication pipe. May be connected.

In the above embodiment, the sub-tank has been described as a resin molded product. However, for example, a metal sub-tank may be used. Further, the above-mentioned sub-tank does not have a pressure-type cap for adjusting the pressure, but the present invention may be applied to a cooling device having such a pressure-type cap or a pressure valve.

In the above embodiment, the cooling device has a cross-flow radiator. However, the present invention can be applied to a cooling device having a down-flow radiator.

[0022]

[Effects of the Invention] As described above, according to the present invention,
An engine sub-tank structure that can be positioned relatively downwards is provided, which makes it possible to achieve both a low bonnet of the vehicle body and a desired arrangement of the sub-tank.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a cooling device for an engine having a sub-tank structure according to the present invention.

FIG. 2 is a longitudinal sectional view showing a structure of a sub-tank arranged in a vehicle.

FIG. 3 is a plan view of the sub tank shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Engine 12 Cooling device 14 Radiator 40 Subtank 42 Separation chamber 43 Partition wall 44 Expansion chamber 46 Communication pipe

Continuation of the front page (72) Inventor Seiji Namba 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) Reference Jikgyo Hei 3-24831 (JP, Y2)

Claims (3)

(57) [Scope of request for utility model registration] 1. A sub-tank connected to a cooling water circuit of an engine, the sub-tank having a water / water separation space for separating water / water of a cooling water, and a change in volume of cooling water and air in the water / water separation space. A sub-tank structure for an engine having an expansion space that compensates for the following: the sub-tank is a separation chamber that configures the air / water separation space; an expansion chamber that configures the expansion space isolated from the separation chamber; And a communication means for mutually communicating the expansion chamber with the separation chamber, wherein the expansion chamber is disposed below the separation chamber. 2. The expansion device according to claim 1, wherein the sub-tank includes the separation chamber and the expansion chamber.
It is characterized by being a resin tank made by integrally molding the chamber
The engine sub-tank structure according to claim 1. 3. The expansion device according to claim 2, wherein the sub-tank is connected to the separation chamber and the expansion chamber.
Claims: It is provided with a partition which divides a tension room.
3. The sub-tank structure of the engine according to 1 or 2.