JPH057930U - Cooling device for internal combustion engine - Google Patents

Abstract

(57) [Summary] [Purpose] Immediately after stopping the internal combustion engine, the cooling water is caused to flow without using a battery power source to prevent boiling of the cooling water. [Composition] A water cooling jacket around a cylinder of the internal combustion engine 1, a water cooling jacket of a turbocharger 4, and a radiator 3.
In a cooling device for an internal combustion engine having a water pump 5 that circulates cooling water in a cooling water passage between and, a pneumatically driven auxiliary water is provided at an appropriate position in the cooling water passage that passes through a high temperature portion such as the turbocharger 4. A pump 13 is provided, and high-pressure air from a pressure tank 14 for a brake booster is introduced into an auxiliary water pump 13 via an opening / closing valve 15.
The on-off valve 15 is controlled by the control means 16 which receives the temperature detection signal.
Is controlled to open and close, and the cooling water is caused to flow by the auxiliary water pump 13 at a temperature at which the cooling water is boiled immediately after the internal combustion engine is stopped.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cooling device for an internal combustion engine, and more particularly to a cooling device that prevents boiling of cooling water immediately after the internal combustion engine is stopped.

[0002]

[Prior Art]

 Generally, a cooling device for an internal combustion engine draws in cooling water cooled by a radiator by a water pump that is driven in conjunction with the rotation of a crankshaft, and directs it to a water cooling jacket around a cylinder of an internal combustion engine or a water cooling jacket for a turbocharger. The cooling water that has been sent out and cooled respectively, and the cooling water that has become hot after cooling is reintroduced into the radiator so that the cooling water is circulated during operation of the internal combustion engine to cool the required locations. Has been.

It is also known that an electric water pump is used instead of a mechanical water pump that is linked to a crankshaft.

Further, Japanese Utility Model Laid-Open No. 62-746 discloses a turbocharger cooling device that supplies cooling water by increasing the pressure in the water cooling jacket when the internal combustion engine is stopped.

[0005]

[Problems to be solved by the device]

 However, in a cooling device using a mechanical water pump, when the internal combustion engine stops, the flow of cooling water also stops immediately, so that the boiling of cooling water occurs in the high temperature part of the internal combustion engine, especially in the water cooling jacket part of the turbocharger. It may occur. Due to this boiling, components such as antifreeze chemicals and rust preventives in the cooling water precipitate, clogging of the cooling water passages occurs, and the antifreeze and rust preventive performance of the cooling water deteriorates. The generated air bubbles remain and mix in the cooling water, which hinders the performance of the water pump.

When an electric water pump is provided, it is possible to prevent boiling by operating this electric water pump after the internal combustion engine is stopped to circulate cooling water, but there is a margin in the charge and discharge balance of the battery. Not applicable if there is no.

Further, the configuration disclosed in the above publication does not disclose a specific cooling water supply means.

In view of the above-mentioned conventional problems, the present invention provides a cooling device for an internal combustion engine, which allows cooling water to flow and prevent boiling of the cooling water without using a battery power source immediately after the internal combustion engine is stopped. The purpose is to provide.

[0009]

[Means for Solving the Problems]

 The present invention relates to a cooling device for an internal combustion engine having a water pump for circulating cooling water in a cooling water passage between a water cooling location of an internal combustion engine and a radiator, and an air-powered auxiliary water pump is provided at an appropriate place in the cooling water passage. After the internal combustion engine is stopped, the high pressure air of the accumulator tank for the brake booster is introduced into the auxiliary water pump through the open / close valve, and after the internal combustion engine is stopped, the open / close valve is opened by using the temperature detection signal at the appropriate point in the cooling water flow path as input. It is characterized in that a control means for controlling opening / closing is provided.

[0010]

[Action]

 According to the present invention, it is possible to detect the temperature of a high temperature portion such as a turbocharger where the cooling water may boil if the circulation of the cooling water is stopped immediately after the internal combustion engine is stopped, and input the detection signal to the control means. When the temperature reaches a temperature at which the cooling water boils immediately after the internal combustion engine stops, the control means opens the on-off valve, and the high-pressure air in the brake booster accumulator tank is supplied to the auxiliary water pump. Since the cooling water in the cooling water passage is made to flow, it is possible to reliably prevent boiling of the cooling water without using a battery power supply.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, reference numeral 1 is an internal combustion engine, and 2 is a water cooling jacket around a cylinder which is schematically shown. 3 is a radiator that cools the high temperature cooling water by exchanging heat with the cooling air of the outside air, and 4 is a turbocharger. The cooling water cooled by the radiator 3 is sucked by the water pump 5 through the cooling water supply pipe 6, sent into the water cooling jacket 2, and the cooling water discharged from the water cooling jacket 2 is cooled by the thermostat 7. It is supplied to the radiator 3 through the water discharge pipe 8. Further, the thermostat 7 and the suction port of the water pump 5 are connected by the bypass passage 9, and during the cold start, the thermostat 7 operates as shown by a phantom line to close the cooling water discharge pipe 8 and open the bypass passage 9. The cooling water bypasses the radiator 3 and flows.

Reference numeral 10 denotes a reserve tank that automatically replenishes cooling water and releases excess cooling water, and is arranged above the cooling water discharge pipe 8 and the radiator 3.

Reference numeral 11 denotes a turbocharger cooling water supply pipe for supplying cooling water to the turbocharger 4, which is branched from the cooling water discharge pipe 8 so as not to overcool the turbocharger. Reference numeral 12 denotes a turbocharger cooling water discharge pipe for returning the cooling water discharged from the turbocharger 4 to the suction side of the water pump 5, and a pneumatically driven auxiliary water pump 13 is disposed in the middle thereof. The auxiliary water pump 13 is configured to flow the cooling water in the direction opposite to the direction of the normal cooling water (the direction of the solid arrow) (the direction of the broken arrow), and the cooling water flows upward. There is. As a drive source of the auxiliary water pump 13, high-pressure air in a pressure tank 14 for a brake booster is introduced via an opening / closing valve 15. The on-off valve 15 is controlled to be opened and closed by the control means 16, and the control means 16 receives the detection signals of the rotation sensor 17 for detecting the rotation speed of the internal combustion engine and the temperature sensor 18 for detecting the temperature of the turbocharger 4 to open and close the valve. The valve 15 is normally closed, and is opened when the temperature of the turbocharger 4 is a temperature at which the cooling water is boiled while the rotation of the internal combustion engine 1 is stopped.

In the above configuration, the water pump 5 stops operating due to the stop of the internal combustion engine 1, and the circulation of the cooling water to the turbocharger 4 stops, so that the cooling water may boil in the turbocharger 4. When the temperature becomes high, a detection signal is input from the rotation sensor 17 and the temperature sensor 18 to the control means 16, so that the control means 16 opens the open / close valve 15 and the high pressure air in the accumulator tank 14 is fed to the auxiliary water pump 13. And the auxiliary water pump 13 is driven. As a result, the cooling water in the turbocharger cooling water discharge pipe 12 flows toward the turbocharger 4, and the cooling water in the turbocharger 4 flows, whereby boiling of the cooling water is reliably prevented. Further, even if the cooling water boiled a little before that and bubbles are generated, the cooling water is caused to flow upward, so that the bubbles are smoothly discharged toward the reserve tank 10, and the bubbles are discharged into the cooling water passage. Can be prevented from remaining. Thus, the boiling of the cooling water can be reliably prevented without using the battery power supply.

Although the capacity of the pressure accumulating tank 14 is limited and the operating time of the auxiliary water pump 13 is limited, if the cooling water is allowed to flow within a few seconds, it is possible to prevent the boiling of the cooling water and to generate bubbles. Can be eliminated, so that the function can be sufficiently exerted.

Further, although the rotation sensor 17 is provided to detect the stop of the internal combustion engine 1 in the above-described embodiment, the rotation stop may be detected by using signals of various accessories of the internal combustion engine 1.

[0018]

[Effect of the device]

 According to the cooling device for an internal combustion engine of the present invention, when the temperature of the cooling water boils in a high temperature portion such as a turbocharger due to the circulation stoppage of the cooling water immediately after the internal combustion engine stops, the on-off valve is controlled by the control means. High pressure air from the accumulator tank for the brake booster is opened and supplied to the auxiliary water pump, and the cooling water in the cooling water passage is made to flow by this auxiliary water pump, which prevents boiling of the cooling water. The components such as antifreeze chemicals and anticorrosives in the cooling water are deposited to clog the cooling water passages, the antifreeze of cooling water is deteriorated and the anticorrosion performance is deteriorated. It can surely prevent performance from being hindered. In addition, after the internal combustion engine is stopped, high-pressure air from the accumulator tank, which is unnecessary for the brake booster, is used as the drive source, and the battery power supply is not used, so it can be applied to automobiles with insufficient charge / discharge balance. To be effective.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

[Explanation of symbols]

 2 Internal combustion engine 3 Radiator 4 Turbocharger 5 Water pump 6 Cooling water supply pipe 8 Cooling water discharge pipe 11 Cooling water supply pipe for turbocharger 12 Cooling water discharge pipe for turbocharger 13 Auxiliary water pump 14 Accumulation tank 15 Opening valve 16 Control means 17 Rotation sensor 18 Temperature sensor

Claims (1)

[Claims for utility model registration] Claims: 1. A cooling device for an internal combustion engine, comprising a water pump for circulating cooling water in a cooling water passage between a water cooling portion of an internal combustion engine and a radiator, at an appropriate portion of the cooling water passage. An auxiliary water pump driven by air pressure is installed, and the high-pressure air from the accumulator tank for the brake booster is introduced into the auxiliary water pump through an on-off valve, and after the internal combustion engine is stopped, a signal for detecting the temperature at an appropriate point in the cooling water flow path. A cooling device for an internal combustion engine, comprising: a control unit that controls opening and closing of an on-off valve by inputting the input.