JPH0642349A - Cooling liquid temperature controller - Google Patents

Abstract

PURPOSE:To reduce thermal load received by auxiliary devices inside an engine room from a radiator so as to thermally protect them by lowering a temperature rapidly when the cooling water of an engine is set to a high temperature in the case of a stopped engine. CONSTITUTION:Normally closed solenoid valve 8 is arranged in a pipe passage 7 which connects the upper tank 2 to the condense tank 6 of a radiator 1, and if a cooling water temperature higher than a set value is detected by a temperature sensor 9, when stopped operation of an engine is detected by an oil pressure sensor 11, a control circuit 10 is operated so as to open the solenoid valve 8, and cooling water or steam at a high temperature is discharged from a cooling water passage to the condense tank 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the temperature of engine coolant in a vehicle engine, especially when the engine is stopped.

[0002]

2. Description of the Related Art In a conventional vehicle, a pressure adjusting valve is attached to a radiator cap for cooling engine cooling water, and when the cooling water temperature rises as the engine temperature rises, the pressure in the cooling water passage exceeds a predetermined value. , The above-mentioned pressure control valve is opened to guide high temperature cooling water or steam to the condensation tank, where it is condensed and cooled to regulate dangerous pressure rise in the cooling water passage, while the cooling water temperature is lowered by cooling water passage. If the pressure of is reduced below the specified value,
The pressure regulating valve is opened to return the cooling water from the condensation tank to the radiator.

However, when the operation of the engine is stopped when the cooling water in the radiator is boiling, such as when the vehicle stops at a high speed for a long distance in summer, the high temperature cooling water is used. Due to the heat radiation from the radiator due to, the auxiliary machinery in the engine room may be heated strongly and their functions may be impaired.

For this reason, by the cooling water temperature above the set value and the ignition key OFF signal, high temperature cooling water is discharged from the radiator to lower the pressure of the cooling water passage, and the amount of heat radiation from the radiator to the engine room is reduced. However, it is easy to cause so-called engine stall when the vehicle is running on a congested road in summer, because of unstable idling of the engine, deterioration of drivability, etc.In this case, the ignition key is Since it is not turned off, the heat dissipation mechanism does not operate, and thus there is a problem that the protection of the accessories in the engine room becomes insufficient.

[0005]

SUMMARY OF THE INVENTION According to the present invention, when the engine-related temperature is high while the operation of the engine is stopped, the temperature of the cooling water system passage is surely lowered to ensure that the auxiliary equipment installed in the engine room. It is intended to reduce the heat load on the machinery.

[0006]

For this reason, the cooling liquid temperature control apparatus according to the present invention includes a flow passage connecting the engine cooling liquid passage and the condensation tank, a normally closed solenoid valve provided in the flow passage, It has a temperature sensor of an engine-related temperature and an operation sensor of the engine, and opens the solenoid valve when the temperature sensor detects a temperature equal to or higher than a set value and the operation sensor detects an operation stop of the engine. Is configured.

[0007]

Therefore, if the engine-related temperature is equal to or higher than the set value when the engine is stopped, the solenoid valve is opened by detecting them by the operation sensor and the temperature sensor, respectively, and the flow path from the engine coolant system passage is opened. Because hot coolant or its vapor is released through the condenser tank,
The pressure and temperature of the engine coolant system line will drop rapidly,
It is possible to reduce heat radiation from the engine, radiator, etc.

[0008]

Embodiments of the present invention shown in the drawings will be specifically described below. A cap 4 having a pressure regulating valve 3 incorporated in an upper tank 2 of a radiator 1 into which engine cooling water is guided from an engine (not shown) mounted on a vehicle.
Is attached, the inside of the cap 4 is communicated with the bottom of the condensation tank 6 by the pipe line 5, and the inside of the upper tank 2 and the pipe line 5 are connected by the pipe line 7.
Is provided with a normally closed solenoid valve 8.

A temperature sensor 9 for detecting the internal cooling water temperature is attached to the upper tank 2, and the temperature signal is input to the control circuit 10, while the oil pressure sensor 11 for the oil pump driven by the engine is also provided. Is input to the control circuit 10, the temperature signal of the temperature sensor 9 indicates a temperature equal to or higher than a set value, and if the oil pressure signal of the oil pressure sensor is not input, the control circuit 10 opens the solenoid valve 8. It has become.

In the above apparatus, when the temperature of the cooling water in the cooling water passage rises and boils or evaporates as the engine temperature rises, and the pressure in the cooling water passage reaches a predetermined value on the high pressure side, which is dangerous. Since the pressure adjusting valve 3 opens and the inside of the upper tank 2 communicates with the inside of the condensation tank 6 via the cap 4 and the pipe line 5, high-temperature cooling water or steam is guided from the upper tank 2 to the condensation tank 6 to cool the cooling water system. When the pressure of the passage is kept within a predetermined value on the high pressure side, and when the pressure of the cooling water passage falls below a predetermined value on the low pressure side, the pressure regulating valve 3 opens and, conversely to the above, cools from the condensation tank 6 to the radiator 1. Water is sucked in.

On the other hand, if the cooling water is at a particularly high temperature when the engine is stopped, such as when the vehicle stops at a high speed for a long distance in the summer, the radiator 1
High temperature boiling water and steam remain in the upper tank 2 of the above, and the temperature sensor 9 causes the temperature of the cooling water to be set to, for example, 110.
When the temperature of the cooling water higher than ° C to 115 ° C is detected and the temperature signal is input to the control circuit 10, the oil pump pressure is not generated due to the stop of the engine operation. Since there is no input to 10, the control circuit 10 slowly opens the solenoid valve 8.

Therefore, the high-temperature cooling water and steam in the cooling water system passage are discharged to the condensation tank 6 through the pipe line 7, the pressure of the cooling water system passage is gradually decreased, and the boiling point of the cooling water passage is also decreased. Generation of water vapor in the water system passage and discharge from the water pipe 7 promotes further cooling of the cooling water temperature in the cooling water system passage. Therefore, the cooling water temperature in the cooling water system passage decreases in a shorter time than before. As a result, the amount of heat radiated from the radiator 1 into the engine room is greatly reduced, the heating of the auxiliary equipment installed in the engine room is reduced, and the deterioration of their performance can be easily prevented.

In the above embodiment, the temperature sensor detects the temperature of the cooling water in the upper tank 2 of the radiator 1 and the control circuit determines whether or not the temperature is above a set value. As a related temperature, a temperature sensor is installed to detect the temperature of the engine cooling water while it is being guided from the engine to the radiator, the cooling water temperature in the cooling water jacket of the engine cylinder head, or the temperature of the engine itself. ,
Alternatively, you can divert the air-conditioner water temperature sensor to determine whether or not they detect temperatures above a set value.In addition, install a temperature sensor that detects the ambient temperature in the engine room, It can also be determined by whether or not it detects a set value, for example, 100 ° C or higher.

As the operation sensor for detecting the operation of the engine, in addition to the hydraulic pressure sensor, a pressure sensor for detecting the discharge pressure or the inlet / outlet differential pressure of the cooling water pump, or the engine or an auxiliary device driven by the engine. It is also possible to reliably detect the operation and stop of the engine by using a rotation sensor etc., etc., and it goes without saying that the temperature sensors and the operation sensors can be appropriately combined. Absent.

[0015]

In the coolant temperature control device according to the present invention, when the temperature sensor of the engine-related temperature detects a temperature equal to or higher than the set value when the engine operation sensor detects the stop of the operation of the engine, the normally closed electromagnetic wave is detected. The valve is opened to release the high-temperature cooling liquid or its vapor from the cooling liquid passage to the condensation tank, so that the temperature of the engine cooling liquid passage decreases rapidly, and the heat radiation from the engine and radiator etc. Since it is also possible to reduce the heat load on the auxiliary machines in the engine room and to protect each auxiliary machine thermally, it is possible to easily ensure their functions.

[Brief description of drawings]

FIG. 1 is a system diagram of essential parts in an embodiment of the present invention.

[Explanation of symbols]

 1 Radiator 3 Pressure regulating valve 4 Cap 5 Pipe line 6 Condensation tank 7 Pipe line 8 Normally closed solenoid valve 9 Temperature sensor 10 Control circuit 11 Hydraulic pressure sensor

Claims (2)

[Claims] 1. A temperature sensor having a flow path connecting an engine coolant system path and a condensation tank, a normally closed electromagnetic valve provided in the flow path, a temperature sensor for an engine-related temperature, and an engine operation sensor. Detects a temperature above the set value,
Further, the coolant temperature control device configured to open the solenoid valve when the operation sensor detects that the engine has stopped operating. 2. A temperature sensor having a flow path connecting the engine coolant system path and the condensation tank, a normally closed electromagnetic valve provided in the flow path, an engine room atmosphere temperature sensor, and an engine operation sensor. Is a temperature equal to or higher than a set value, and when the operation sensor detects that the engine has stopped operating, the coolant temperature control device is configured to open the solenoid valve.