JPS6112101B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a cooling device for an internal combustion engine.

Figure 1 shows a cooling system for a conventional internal combustion engine.
An example is shown in the figure, in which the cooling water exiting the cooling water pump 2 driven by the crankshaft 1 cools the cylinder jacket 3 and cylinder head 4 of the internal combustion engine 1A, and is discharged into the cylinder outlet cooling water pipe 5. .

An automatic water temperature adjustment valve 6 is provided in the cylinder outlet cooling water pipe 5, and this adjustment valve 6 closes the bypass passage 8 when the output torque of the engine 1A is large and the temperature of the cylinder exit cooling water is high. The entire amount is sent to the radiator 9 via the cooling water pipe 7. The high-temperature cooling water that has passed through the regulating valve 6 is sucked into the cooling water pump 2 through a return pipe 11 in which the temperature is lowered by the wind from a fan 10 driven by the crankshaft 1 in the radiator 9 .

On the other hand, when the output torque of the engine 1A is small and the cooling water temperature at the cylinder outlet is low, the automatic water temperature adjustment valve 6 stops the flow of cooling water to the cooling water pipe 7, and the entire amount of cooling water is transferred to the bypass passage 8 and the cooling water. The water is drawn directly into the cooling water pump 2 via the water return pipe 11.

Due to the above-described actions, the engine can operate normally by keeping the temperature of the cooling water at the cylinder outlet substantially constant regardless of the magnitude of the output torque of the engine 1A.

However, the conventional cooling device described above has the following drawbacks.

In the above, the fan 10 for lowering the temperature of the cooling water in the radiator 9 is driven by the crankshaft I. This fan drive horsepower is engine 1A
At maximum speed, it becomes 4 to 5% of the engine output,
The shaft output of the engine 1A is reduced by that amount. Further, since the fan 10 is driven by the crankshaft 1, the fan 10 is driven at a rotation speed corresponding to the rotation speed of the engine 1A, regardless of the magnitude of the engine output torque.

Therefore, even when the output torque of the engine 1A is small and the cooling water temperature at the cylinder outlet is low, that is, even when the flow of cooling water to the radiator 9 is stopped by the automatic water temperature regulating valve 6, the fan 10 is driven uselessly. It happens. Therefore, when the engine 1A has a low torque, there is a power loss equivalent to the fan driving horsepower, and the fan 10 generates unnecessary noise.

The present invention has been made in view of the above, and an object of the present invention is to reduce the loss of power for driving the fan by driving the fan only when necessary, and to reduce the noise of the fan especially when the engine has low torque. do.

An embodiment of the present invention will be described below with reference to FIG. 2. Reference numeral 1 indicates a crankshaft of an internal combustion engine 1A;
3 is a cylinder jacket, 4 is a cylinder head, 5 is a cooling water pipe at the outlet of the cylinder head, 6 is an automatic water temperature adjustment valve, 9 is a radiator, and 10 is a radiator fan. , 11 is a cooling water pipe that connects the radiator 9 and the suction port of the cooling water pump 2, 8 is a bypass pipe that connects the automatic water temperature adjustment valve 6 and the cooling water pipe 11, and 15 is an exhaust passage. It is similar to that of .

100 is a known Stirling engine, and a crankshaft 12 of the Stirling engine 100 is connected to the fan 10. 13 is a high temperature cylinder, 1
4 is a low temperature cylinder.

21 and 22 are working gas pipes connecting the high temperature cylinder 13 and the low temperature cylinder 14;
A heater 16, a heat accumulator 17, and a cooler 18 are disposed in the heaters 1 and 22.

The heater 16 faces into the exhaust passage 15 of the engine 1A and exchanges heat between the exhaust gas from the engine 1A and the working gas, and the cooler 18 faces into the cooling water pipe 5 at the engine outlet and is used to exchange heat between the exhaust gas from the engine 1A and the working gas. This is to exchange heat between the cooling water discharged from the 1A cylinder head 4 and the working gas. Reference numeral 19 denotes a hydraulic turbine fixed to the crankshaft 12 of the Stirling engine 100, which is installed in the cooling pipe 7 between the control valve 6 and the cooling water inlet of the radiator 9, and is configured to cool water flowing through the pipe 7. Driven by

In the above device, when the internal combustion engine 1A is operated, the high temperature cylinder 13 of the Stirling engine 100
The working gas flowing in and out of the low temperature cylinder 14 is heated in the heater 16 by the exhaust gas from the engine 1A, and the working gas flowing in and out of the low temperature cylinder 14 is cooled in the cooler 18 by cooling water discharged from the engine.
When the output torque of the internal combustion engine 1A increases, the temperature Te of the exhaust gas flowing through the exhaust passage 15 and the temperature Tc of the cooling water flowing through the cooling water pipe 5 rise. When the cooling water temperature Tc at the outlet of the cylinder head 4 exceeds a certain value, the automatic water temperature adjustment valve 6 opens and the cooling water begins to flow through the cooling water pipe 7.

As a result, the hydraulic turbine 19 provided on the crankshaft 12 begins to rotate, and the Stirling engine 100 is started.

In this case, the increase in the exhaust temperature Te is the cooling water temperature Tc
The temperature difference Te-Tc is generated, and the high-temperature cylinder 13 and the low-temperature cylinder 14 act as a Stirling engine, and the crankshaft 12 directly connected to the fan 10 is driven.

That is, when the output torque of the internal combustion engine 1A is large, the exhaust temperature Te mentioned above reaches a maximum of about 700°C;
Since the cooling water temperature Tc at the cylinder head outlet is at most 100°C, a temperature difference Te-Tc occurs in the working gas of the Stirling engine 100. Therefore, the high temperature cylinder 13 and the low temperature cylinder 14 act as a Stirling engine to rotate the crankshaft 12, and the fan 10 coaxial therewith is driven to rotate.

Generally, the total heat amount of the above exhaust gas is 1 A of internal combustion engine.
The shaft output of a conventional Stirling engine is about the same as that of the engine, and the thermal efficiency of a conventional Stirling engine is as high as 35%. Obtainable. When the output torque of the internal combustion engine 1A is small,
Since the cooling water temperature Tc at the cylinder head outlet becomes low and the automatic water temperature adjustment valve 6 stops the flow of cooling water to the cooling water pipe 7, the Stirling engine 100 does not start, and the exhaust temperature Te also decreases, resulting in a temperature difference.
Te−Tc becomes smaller, Stirling engine 100
will stop automatically.

The cooler 18 is installed in the cooling water pipe 11 leading to the suction port of the cooling water pump 2 or in the cooling water pipe 11 leading to the suction port of the cooling water pump 2
and the cylinder jacket 3.
It may be provided inside. In this case, the cooling water temperature Tc is lower than in the first embodiment, so Te
- Tc increases, and the thermal efficiency of the Stirling engine 100 increases.

The present invention is constructed as described above, and according to the present invention, the Stirling engine is driven by the amount of heat of the exhaust gas of the internal combustion engine, and the cooling fan is directly connected to the output shaft of the Stirling engine, so it is different from the conventional one. In addition, there is no need to use part of the internal combustion engine's output to drive the cooling fan, and the driving power for the fan is covered by the engine's exhaust heat. Therefore, the effective shaft output of the internal combustion engine increases, and the fuel consumption rate of the engine can be reduced accordingly.

Also, when the output torque of the internal combustion engine is small and the coolant temperature is low, the hydraulic turbine is not driven.
Moreover, since the exhaust temperature also decreases, the Stirling engine is not driven, and therefore the fan does not rotate unnecessarily. That is, the fan is not operated in the entire operating range of the internal combustion engine as in the conventional case, but is operated only in the required operating range where the output torque of the engine is high. Therefore, the fuel consumption rate in the low output range of the engine is reduced and the generation of noise is prevented.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an example of a conventional internal combustion engine cooling device, and FIG. 2 is a system diagram showing an example of a conventional internal combustion engine cooling device.
FIG. DESCRIPTION OF SYMBOLS 1... Crankshaft of internal combustion engine, 2... Cooling water pump, 1A... Internal combustion engine, 100... Stirling engine, 12... Crankshaft of Stirling engine, 13
...High temperature cylinder, 14...Low temperature cylinder, 15...Exhaust passage, 16...Heater, 18...Cooler, 5, 7,
11...Cooling water pipe, 9...Radiator, 10...Cooling fan, 21, 22...Working gas passage.

Claims (1)

[Claims] 1. A heater for exchanging heat between the working gas and the exhaust gas discharged from the internal heat engine to raise the temperature of the working gas in the working gas pipe connecting the low-temperature cylinder and the high-temperature cylinder; The output shaft of a Stirling engine is connected to a radiator that cools the engine's cooling water by connecting the output shaft of a Stirling engine, which is equipped with a cooler that lowers the temperature of the working gas by exchanging heat between the working gas and the engine's cooling fluid near the low-temperature cylinder. A cooling device for an internal combustion engine, characterized in that it is connected to a cooling fan.