JPH0444083B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

This invention removes air bubbles in cooling water while
The present invention relates to an improvement in a water-cooled cooling device for a vehicle engine that is provided with an expansion tank that also absorbs the expansion of cooling water.

[Conventional technology]

Conventionally, for example, as shown in FIG. 1, a main circulation system is constructed by connecting a water jacket 3 surrounding a heated portion of an engine 1 to a radiator 4 dissipating heat through water tubes 6 and 7.
This main circulation system is provided with a water pump 8 that circulates the cooling water, and an expansion tank 10 that removes air bubbles from the cooling water and also absorbs the expansion of the cooling water is located at the highest part of the main circulation system H ( The upstream pipe line 11 is connected to the highest part of the tank U of the radiator 4.
The expansion tank 10 has a pressurized camp 1 which is connected to the vicinity of the suction part A of the water pump 8 via a downstream pipe line 12, and which communicates with the atmosphere through a positive pressure valve and a negative pressure valve.
Water-cooled cooling system 2 for a vehicle engine provided with 4
It has been known. In this type of system, forced air from a cooling fan 5 driven by the engine 1 is blown onto the radiator 4 to increase the cooling of the cooling water, and a pressurized cap 14 provided in the expansion tank 10 is used to increase the cooling of the cooling water. The expansion tank 10 attempts to separate the air and water in the cooling water while balancing the pressure fluctuations in the main circulation system due to the temperature rise and fall with the atmospheric pressure via the overflow pipe 15. A thermostat 9 installed at the connection with the water pump 6 sets the amount of circulating water in accordance with the temperature of the cooling water to prevent cavitation in the main circulation system (especially near the suction part A of the water pump 8). This prevents damage to the cooling device 2 under various load conditions of the engine 1. Furthermore, a one-way valve (not shown) that allows cooling water to flow only from the expansion tank 10 side to the water pump 8 side is provided in the middle of the downstream pipe line 12 to regulate the circulation direction of the cooling water and improve efficiency. Some systems are designed to circulate cooling water. Note that the portion 13 to which the pressure cap 14 is attached is used as a cooling water inlet.

[Problem to be solved by the invention]

However, in the water-cooled cooling system for a vehicle engine configured as described above, the part where the pressurized cap of the expansion tank is installed is the cooling water inlet, so it can be easily accessed from the outside of the vehicle bonnet. In order to be able to inject cooling water into the water cooling system, the expansion tank must be installed so that the cooling water inlet is located at the highest point of the water-cooled cooling system, so the set height of the expansion tank must be The degree of freedom in vehicle design was limited. Therefore, this invention takes these problems into account and removes air bubbles in the cooling water while relaxing the restrictions on the height of the expansion tank that also absorbs the expansion of the cooling water. An object of the present invention is to provide a water-cooled cooling device for a vehicle engine that can improve the degree of freedom in vehicle design due to the presence of an expansion tank without impairing the function of the expansion tank.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a main circulation system in which a water jacket including a heating part of an engine and a radiator for dissipating heat are connected via a water tube, and the main circulation system includes A water pump that circulates cooling water is provided, and an expansion tank that removes air bubbles in the cooling water and also absorbs the expansion of the cooling water is connected to the highest part of the main circulation system via an upstream pipe. The expansion tank is provided with a pressurizing cap that is connected to the vicinity of the suction portion of the water pump via a downstream pipe line, and communicates with the atmosphere through a positive pressure valve and a negative pressure valve. In the water-cooled cooling system for a vehicle engine, the conduit is provided with a one-way valve that allows the cooling water to flow only from the expansion tank side to the water pump side. A connecting portion of the upstream pipe to the expansion tank side is provided, a sealable cooling water inlet is separately provided at the highest part of the main circulation system, and the cooling water inlet is provided at a lower position than the cooling water inlet. It features an expansion tank.

[Effect]

According to this invention, a connection part with the expansion tank side of the upstream pipe is provided at the bottom of the expansion tank, and a sealable cooling water inlet is provided at the highest part of the main circulation system, which is different from the pressurized cap. A separate expansion tank is installed at a lower position than this cooling water inlet, so the expansion tank is set up to remove air bubbles from the cooling water while also absorbing the expansion of the cooling water. The height can be set depending on the vehicle design. Therefore, inconvenience in vehicle design due to the presence of the expansion tank can be improved without impairing the function of the expansion tank.

【Example】

The present invention will be explained below with reference to the drawings. FIG. 2 is a sectional view of a main part of a water-cooled cooling device for a vehicle engine according to the present invention. Incidentally, parts or members that are the same or equivalent to those of the conventional example are given the same reference numerals or symbols, and redundant explanation will be omitted. A connecting portion is provided at the bottom of the expansion tank 10 to connect the upstream pipe line 11 to the expansion tank 10 side. With this configuration, even if the pressure in the main circulation system decreases due to the contraction of cooling water due to the temperature drop in the main circulation system after the engine 1 stops operating, the highest part H of the main circulation system is expansion tank 1
Cooling water containing no air bubbles in the expansion tank 10 is drawn in, and air in the expansion tank 10 is not drawn in, so that air-water separation in the cooling water is reliably performed. The expansion tank 10 is connected to the radiator 4
It is connected via an upstream pipe line 11 to the highest part H of the main circulation system provided in the upper tank U of. At the highest point H of the main circulation system, a cooling water inlet 13 is provided separately from the pressurized cap 14 of the expansion tank 10. The cooling water inlet 13 can be sealed by an inlet cap 21 . The expansion tank 10 is provided at an arbitrary set height so as to be located at a lower position than the cooling water inlet 13. Next, the operation of the water-cooled cooling system for a vehicle engine configured as described above will be explained. When the engine 1 is operated, the cooling water is circulated through the main circulation system by the rotation of the water pump 8, and the vehicle engine 1 is cooled, as in the case of the conventional example. Here, the highest part H of the main circulation system is in a high pressure state because the cooling water that has been discharged from the water pump 8 and has not yet suffered a large pressure loss passes therethrough. On the other hand, the pressure inside the expansion tank 10 is prevented from exceeding a predetermined upper limit pressure by the pressurizing cap 14, and during normal operation it is lower than the pressure at the highest point H of the main circulation system. Therefore, some of the cooling water that reaches the hot tank U of the radiator 4 is transferred to the highest part H of the main circulation system.
The cooling water is sent through the upstream pipe line 11 into the expansion tank 10, where air bubbles generated in the cooling water are separated. The vicinity of the suction part A of the water pump 8 is in a low pressure state due to the passage of cooling water that has suffered a large pressure loss due to the water flow resistance of the radiator 4, etc., and the pressure inside the expansion tank 10 is low. 14 so that the pressure does not fall below atmospheric pressure, and during normal operation the pressure is higher than the pressure near the suction part A of the water pump 8, so the one-way valve 22 is open and the expansion valve 22 is in an open state. The cooling water from which air bubbles have been removed from the tank 10 is returned to the vicinity of the suction portion A of the water pump 8 via the downstream pipe line 12. Air bubbles in the main circulation system are therefore removed and cooling capacity is maintained. Also, at this time, the suction part A of the water pump 8
The pressure within the expansion tank 10 is introduced into the vicinity, thereby compensating for the pressure loss caused by the water flow resistance of the radiator 4 and the like. As a result, cavitation is less likely to occur, and the rotational speed of the water pump 8 can be increased accordingly, so that the flow rate of cooling water in the main circulation system is also increased, and the cooling capacity is increased. Moreover, when the operation of the vehicle engine 1 stops,
Since the cooling fan 5 and water pump 8 are also stopped, the cooling water no longer circulates, but the bubbles generated in the cooling water move upward and collect at the highest part H of the main circulation system. On the other hand, the cooling water in the main circulation system is
It expands due to residual heat and flows into the expansion tank 10 together with air bubbles gathered at the highest part H of the main circulation system. At this time, since the downstream pipe line 12 is equipped with a one-way valve 22, the cooling water expanded in the main circulation system is passed through the downstream pipe line 12 to the water pump 8.
Since it does not flow from the side toward the expansion tank 10 side, the highest part H of the main circulation system
The collected air bubbles are reliably sent to the expansion tank 10. Furthermore, when the residual heat of the vehicle engine 1 is dissipated and cools down, the temperature of the cooling water decreases and begins to contract, which attempts to lower the pressure in the main circulation system, but with this pressure drop, one-way The valve 22 is opened and the bubble-free cooling water in the expansion tank 10 is drawn into the main circulation system to compensate for the pressure drop in the main circulation system. At this time, since the upstream pipe line 11 is connected to the bottom of the expansion tank 10, the air in the expansion tank 10 flows through the upstream pipe line 11.
are not drawn into the main circulatory system via the It should be noted that even if the cooling water shrinks, the expansion tank 10 will continue to shrink because the pressure cap 14 is attached to the expansion tank 10.
Needless to say, the interior and main circulation system will not be in a negative pressure state with respect to the outside. In this way, the cooling water in the main circulation system is made bubble-free. As explained above, according to this embodiment,
A connection part with the upstream pipe line 11 on the expansion tank 10 side is provided at the bottom of the expansion tank 10, and a sealable cooling water inlet 13 is provided at the highest part H of the main circulation system with a pressurized cap 14. Separately provided,
Since the expansion tank 10 is provided at a lower position than the cooling water inlet 13, the expansion tank 10 is prevented from cavitation by removing air bubbles in the cooling water and also absorbing the expansion of the cooling water. Inconveniences in vehicle design can be improved without sacrificing functionality. Note that in this embodiment, the upstream pipe line 11
Although the highest part H of the main circulation system that opens is located at the top tank U of the radiator 4, it goes without saying that the present invention is not limited to this.

【Effect of the invention】

According to this invention, a water jacket containing a heating part of the engine and a radiator that dissipates heat are connected via a water tube to form a main circulation system, and this main circulation system includes a water jacket that circulates cooling water. An expansion tank is provided with a pump, which removes air bubbles from the cooling water, and also absorbs the expansion of the cooling water. The pump is connected to the vicinity of the suction section via a downstream pipe, the expansion tank is provided with a pressurized cap communicating with the atmosphere via a positive pressure valve and a negative pressure valve, and the downstream pipe is connected to the In a water-cooled cooling system for a vehicle engine, the vehicle engine water-cooling system is provided with a one-way valve that allows the cooling water to flow only from the expansion tank side to the water pump side. A connection part with the expansion tank side is provided, a sealable cooling water inlet is separately provided at the highest part of the main circulation system, and the expansion tank is located at a lower position than the cooling water inlet. This design eliminates air bubbles in the cooling water while also easing restrictions on the height of the expansion tank, which also absorbs the expansion of the cooling water, reducing the degree of freedom in vehicle design due to the presence of the expansion tank. can be improved without impairing the function of the expansion tank.

[Brief explanation of drawings]

FIG. 1 shows a conventional example, and is a sectional view of a water-cooled cooling device for a vehicle engine, and FIG. 2 is a sectional view of a main part showing an embodiment of the present invention. 1...Engine, 3...Water jacket (main circulation system), 4...Radiator (main circulation system), 6,
7...Water tube (main circulation system), H...Top part of the main circulation system, 8...Water pump, A...
Suction part of water pump, 10... Expansion tank, 11... Upstream pipe line, 12... Downstream pipe line, 13... Cooling water inlet, 14... Pressure cap, 21... Inlet Cap, 22...One-way valve.

Claims (1)

[Claims] 1 A water jacket containing a heating part of the engine and a radiator that dissipates heat are connected via a water tube to form a main circulation system, and the main circulation system is provided with a water pump that circulates cooling water. While removing air bubbles in the cooling water,
An expansion tank that also absorbs the expansion of the cooling water is connected to the highest part of the main circulation system via an upstream pipe line, and is also connected to the vicinity of the suction part of the water pump via a downstream pipe line. The expansion tank is provided with a pressurized camp that communicates with the atmosphere through a positive pressure valve and a negative pressure valve, and the downstream pipe is provided with a pressurized cap that communicates with the atmosphere only from the expansion tank side to the water pump side. In a water-cooled cooling system for a vehicle engine that is equipped with a one-way valve that allows the flow of cooling water,
A connecting portion of the upstream pipe to the expansion tank is provided at the bottom of the expansion tank, a sealable cooling water inlet is provided at the highest part of the main circulation system, and the cooling water inlet is provided at the top of the main circulation system. A water-cooled cooling device for a vehicle engine, characterized in that the expansion tank is provided at a lower position than the expansion tank.