JPS6135696Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an engine cooling system, and particularly reduces the power consumption of a water pump when the temperature of the cooling water is low, and efficiently heats the cooling water using exhaust heat. This invention relates to an engine cooling system that enables

Conventionally, in a water-cooled engine using a water pump, when the temperature of the cooling water is below a certain value, the cooling water that has passed through the engine from the water pump does not flow to the radiator due to the action of the thermostat, but instead goes through the bypass and is sent to the water pump. It was designed to flow to the suction side of the tank and circulate. However, according to the conventional example, the entire amount of cooling water flowing out from the discharge side of the water pump is always sent to the engine, which cools the engine more than necessary, which takes a long time to run the machine and puts the full load on the water pump. Therefore, the power consumption of the water pump is large, and the loss of horsepower is large when the cooling water is at a low temperature. Further, in the conventional example, no attempt has been made to effectively utilize the heat of the exhaust gas, which becomes hot immediately after the engine is started, to help raise the temperature of the cooling water. Unexamined Japanese Patent Publication 1972-
Even the inventions described in JP-A No. 18551 and JP-A-52-40239 do not solve all of these drawbacks, and there remains room for improvement.

The present invention was devised to eliminate the drawbacks of the prior art described above, and its purpose is to minimize the amount of water required during warm-up operation when the temperature of the cooling water is low in a water-cooled engine using a water pump. The purpose of this system is to allow only a limited amount of cooling water to flow to the engine, while other cooling water is returned to the intake side of the water pump through a bypass.This also reduces the power consumption of the water pump when the cooling water is low. , to reduce engine horsepower loss. Another purpose is to use engine exhaust heat to heat the cooling water that does not flow into the engine but is returned to the water pump, rapidly increasing the temperature of the cooling water, shortening warm-up time, and reducing fuel consumption. It is to aim for it.

In short, the present invention provides, in a cold-cooled engine equipped with a water pump, a bypass connected to the discharge side and suction side of the water pump,
At a branch point between the flow path from the discharge side of the water pump to the engine and the bypass, when the temperature of the cooling water is low, a part of the cooling water is flowed to the engine and passed through the bypass to the suction side of the water pump. In contrast, a thermo valve is installed to allow the entire amount of cooling water to flow to the engine when the temperature of the cooling water is high. It is characterized in that a heat exchanger is provided to heat the cooling water in the bypass.

The present invention will be explained below based on embodiments shown in the drawings. In FIG. 1, a water-cooled engine 1 includes a water pump 2, and a bypass 3 is provided that is continuously connected to a discharge side 2a and a suction side 2b of the water pump. At a branch point 5 between a flow path 4 leading from the discharge side 2a of the water pump 2 to the engine 1 and the bypass 3, when the temperature of the cooling water is low, a part of the cooling water is flowed to the engine 1 and a bypass 3 is connected.
The thermo valve 6 is configured to flow the entire amount of cooling water to the engine 1 when the temperature of the cooling water is high, whereas the cooling water is returned to the suction side 2b of the water pump 2 through the cooling water.
is installed, and furthermore, in the middle of Bypass 3,
A heat exchanger 7 is provided that absorbs exhaust heat from the engine 1 and heats the cooling water in the bypass 3.

In FIG. 1, 8 is a cooling water water pipe leading from the engine 1 to the thermostat 9, 10 is a known radiator bypass, 11 is an atspa hose, 1
2 is a radiator, 13 is a lower hose, and 14 is a water pipe from the lower hose to the water pump 2.

The heat exchanger 7 is thermally connected to the exhaust pipe 15, and the heat exchanger may be brought into direct contact with the exhaust pipe 15, or the heat pipe 16 may be used to connect its evaporation section 16a to the exhaust pipe 15. In addition, the condensing section 16b may be provided in the heat exchanger 7.

Next, the thermovalve 6 will be explained. As shown in FIGS. 2 to 4, the thermovalve 6 has the following features:
Piston valve 17 and wax element 18
, a mounting member 19 of the wax element, and a needle 20 connecting the piston valve 17 and the wax element 18, one end of which is fixed to the wax element 18 and the other end of which is fixed to the piston valve 17, and they are pulled together. It consists of a spring S that functions as follows, and a stopper member 21. The piston valve 17 has an open upper part 17a and an open lower part 17a.
b is closed and a plurality of water passage holes 17c are provided, and the water passage holes 17c are slidably inserted into the water pipe 22 constituting the flow path 4. The needle 20 is pushed downward by the wax element 18 as the temperature of the cooling water increases, and is pulled up by the spring S as the temperature decreases. The mounting member 19 is provided with a plurality of water supply holes 19a and is fixed within the water pipe 22. The stopper member 21 is provided with a plurality of water supply holes 21a,
The stopper member 21 has its upper surface 21b fixed in the water pipe 22 at a position slightly lower than the inlet 3a of the bypass 3.

The present invention is constructed as described above, and its operation will be explained below. When starting the engine 1 in cold weather, etc., if the coolant temperature is below a certain value, the piston valve 17 is pulled up by the spring S as shown in FIG. Since the cooling water also moves upward, part of the cooling water flows through the flow path 4 to the engine 1, that is, the cylinder block 1a, as shown by arrow A, and the other part flows to the bypass 3, as shown by arrow B. It is heated by the heat exchanger 7 and returned to the suction side 2b of the water pump 2, increasing the pressure on the suction side. Therefore, the temperature of the cooling water rises quickly, and not only the warm-up operation time is shortened, but also the power consumption of the water pump 2 is reduced, and the horsepower loss of the engine 1 is reduced. Since the temperature of the exhaust gas increases at the same time as the engine 1 is started, the heat exchanger 7 is immediately supplied with a certain amount of heat, which is then given to the cooling water.

On the other hand, a part of the cooling water flowing into the cylinder block 1a of the engine 1 flows from the thermostat 9 to the bypass 10 while cooling the engine 1 to the extent that the engine 1 does not overheat.
is returned to the suction side 2b, and the temperature also rises within a short period of time.

As described above, when the cooling water circulates and reaches a suitable level, the force of the wax element 18 of the thermovalve 6 pushing down the piston valve 17 via the needle 20 is stronger than the pulling force of the spring S, and the piston valve 17 is pushed down as shown in FIG. By pressing down as shown in , the bypass 3 is closed, and the entire amount of cooling water flows from the flow path 4 to the engine 1 as shown by arrow A. The thermostat 9 also closes the flow path of the bypass 10, and the cooling water is sent to the radiator 12. The water is passed, cooled by the radiator, and returned to the water pump 2,
Cooling water will now flow through the normal circulation path.

Since the present invention is constructed and operates as described above, in a water-cooled engine using a water pump, during warm-up operation when the temperature of the cooling water is low, only the minimum necessary amount of cooling water is allowed to flow into the engine.
Other cooling water can now be returned to the suction side of the water pump through the bypass, and as a result, the pressure on the suction side of the water pump when the cooling water is low is increased, so power consumption can be reduced.
The effect of reducing engine horsepower loss can be obtained. In addition, the cooling water that does not flow into the engine but is returned to the water pump is heated using engine exhaust heat, which rapidly raises the temperature of the cooling water, shortening warm-up time and reducing fuel consumption. The effect that can be achieved is obtained. Furthermore, in cold weather, heating can start working in a short time after the engine is started, making this an extremely effective device.

[Brief explanation of the drawing]

The drawings relate to embodiments of the present invention; Fig. 1 is a schematic diagram of a cooling system equipped with an engine cooling system according to the present invention, Fig. 2 is an exploded perspective view of a thermovalve, and Fig. 3 shows the temperature of cooling water. FIG. 4 is a longitudinal sectional view showing the operating state of the thermovalve when the temperature of the cooling water is low, and FIG. 4 is a longitudinal sectional view showing the operating state of the thermovalve when the temperature of the cooling water is appropriate. 1 is a water-cooled engine, 2 is a water pump,
2a is the discharge side, 2b is the suction side, 3 is the bypass, 4
5 is a flow path, 5 is a branch point, 6 is a thermovalve, and 7 is a heat exchanger.

Claims (1)

[Scope of utility model registration request] In a water-cooled engine equipped with a water pump, a bypass is provided that is connected to the discharge side and the suction side of the water pump, and cooling water is provided at a branch point between the bypass and the flow path from the discharge side of the water pump to the engine. When the temperature of the cooling water is low, part of the cooling water is passed through the engine and returned to the intake side of the water pump through the bypass, whereas when the temperature of the cooling water is high, the entire amount of the cooling water is sent to the engine. A heat exchanger is provided in the middle of the bypass to absorb the exhaust heat of the engine and heat the cooling water in the bypass. cooling system for the engine.