JPS59128915A - Cooling water passage for internal-combustion engine - Google Patents

Abstract

PURPOSE:To aimt at increasing the quantity of cooling water for a heater, by installing a radiator bypass passage and a heater side cooling passage in parallel, while installing a regulator, which throttles the bypass passage when cooling water pressure is low, in the said bypass passage. CONSTITUTION:Cooling water run past a radiator 3 is sucked in a suction side 4a of a water pump 4 and, after it circulates a water jacket, reaches to a thermostat 2. In time of low temperature in the cooling water, the thremostat 2 is closed whereby the cooling water is designed so as to go back again to the suction side 4a of the water pump 4 via a bypass passage 5. In parallel with this bypass passage 5, there is provided with a heater side cooling water passage 6 having a heater 13. And, at the middle part of the bypass pasage 5, a regulator 8 which throttles a flow area of the bypass passage 5 when cooling water pressure out of the water pump 4 is low is installed, so that the quantity of cooling water for the heater side cooling water passage 6 is made so as to be secured in design.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling water passage for an internal combustion engine, and is particularly effective for use in a diesel engine.

Vehicles equipped with conventional internal combustion engines, particularly direct injection diesel engines, have a problem in that their heaters, which use the heat of cooling water to heat the vehicle, are not as effective in cold weather. This is because when the thermostat is closed, the cooling water is divided into the bypass passage and the heater side cooling water passage, resulting in an insufficient amount of water to the heater.The present invention was devised in view of the above points. The objective is to provide a cooling water bypass passage with a valve that opens and closes depending on the pressure of the cooling water, thereby maintaining the water pressure at a constant value even when the amount of water is small, and increasing the amount of cooling water supplied to the heater.

Therefore, according to the invention, when the thermostat is closed,
Most of the cooling water is supplied to the heater, which improves the effectiveness of the heater.

Next, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a configuration diagram showing a cooling water passage of an internal combustion engine. When the temperature of the cooling water coming out of the head part 1a of the diesel engine 1 is sufficiently high and the thermostat 2 is open,
Flowed to the radiator side.

Then, when the air passes through the radiator 3, it is cooled by air guided by the radiator fan 3a. The cooling water that has passed through the radiator 3 is transferred to the suction side 4a of the water pump 4, which rotates under the driving force of the engine I via the fan belt 7.
is inhaled. Next, the water is discharged into the engine 1 by the pumping action of the water pump 4. The thermostat 2 opens and closes the cooling water passage 12 to the radiator side according to the cooling water temperature. When the thermostat 2 is closed (the cooling water temperature is below 80 to 90°C), the cooling water from the engine 1 is closed. does not flow to the radiator 3, but directly enters the suction side 4a of the water pump 4 through the bypass passage 5.

Also, a heater-side cooling water passage 6 that guides cooling water to the heater 13
is provided in the head portion 1a of the engine 1, and the heater side cooling water passage 6 and the bypass passage 5 are parallel to each other. However, when the inner passages 6.5 are arranged in parallel like this, most of the water passes through the bypass passage 5 and ends up in the water. Therefore, when the water temperature is between 50 and 75 degrees Celsius and the engine is warming up, the water is transferred to the heater. The amount of water (heat) tends to be insufficient. In contrast, in this example, a regulator 8 is provided in the middle of the bypass passage 5, so that the water pressure within the engine 1 is kept constant. FIG. 2 shows details of this regulator 8. The regulator 8 includes a cap portion 9 that moves up and down due to water pressure, a holder portion 10 that supports displacement of the cap portion 9, and a bypass passage 5 that connects the cap portion 9 with the cap portion 9.
It includes a spring 11 that biases in the closing direction.

The engine 1 and the cap part 9 are sealed by a seal part 9b. Therefore, when the engine speed is low and the amount of water discharged from the water pump is small, the water pressure applied to the camp part 9 becomes the set M weight of the spring, and in that case, the seal part 9b is closed. Therefore, the cooling water is
Only a small amount of water passing through the hole 9a and the hole 10a of the holder part 10 flows to the suction side 4a of the water pump '4. This hole 9a,
10a is made sufficiently smaller than the diameter of the conventional bypass passage, and in the low rotation range including idling operation,
There is a young fruit that eliminates the problem of water pressure in the head section decreasing due to the conventional bypass passage being too large in diameter and causing a shortage of water in the heater. When the engine speed increases, the amount of water discharged from the water pump increases, the water pressure within the engine 1 increases, and the pressure applied to the cap portion 9 exceeds the set load of the spring 11. As a result, the camp section 9 descends,
A large amount of cooling water flows from the seal portion 9b to the bypass passage 5.

As explained above, in the present invention, it is possible to reduce the amount of cooling water flowing into the bypass passage in the low rotation speed range of the internal combustion engine such as when idling, and it is possible to increase the amount of water flowing to the heater and improve heating performance. . Furthermore, by flowing a large amount of cooling water to the bypass passage when the engine speed increases, the water pressure in the internal combustion engine does not become abnormally high, thereby ensuring safety.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an example of the cooling water passage of the present invention, and FIG.
The figure is a sectional view showing the ff11 regulator. ■...Internal combustion engine, 3...Radiator, 5...Bypass passage, 6...Heater side cooling water passage, 8...Regulator, 12...Radiator side cooling water passage, 13.
··heater. Representative Patent Attorney Takashi Okabe

Claims (1)

[Claims] A radiator-side cooling water passage that circulates through the radiator, a bypass passage that bypasses the radiator, and a heater-side cooling water passage that circulates through the heater are arranged in parallel, and
A cooling water passage for an internal combustion engine, wherein a regulator is disposed in the bypass passage to detect the pressure of the cooling water, throttle the bypass passage when the pressure is low, and open the bypass passage when the pressure is high.