JP2002138837A - Cooling system for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling system that can quickly increase the temperature of a refrigerant for an engine. SOLUTION: The cooling system for an engine comprises a directional control valve 130 disposed between a control valve 116 and a water pump 115 in a third refrigerant passage 114 so as to control communication and cutoff between the control valve 116 and the water pump 115; and a fifth refrigerant passage 122, a sixth refrigerant passage 123 and a seventh refrigerant passage 125 for interconnecting a first refrigerant passage 111 and the reach of the third refrigerant passage 114 between the directional control valve 130 and the water pump 115, in which fifth to seventh passages a refrigerant is continuously circulated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cooling device for an engine.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing a conventional engine cooling device. In FIG. 1, an engine 10 is provided with a first refrigerant passage 11 therein. The first refrigerant passage 11 is constituted by a water jacket formed inside the cylinder block 10a and the cylinder head 10b of the engine. The refrigerant flowing through the first refrigerant passage 11 exchanges heat with the cylinder block 10a and the cylinder head 10b of the engine 10 to cool them. The first refrigerant passage 11 has one inlet (inlet) 11a and a first outlet (outlet) 11
b, two outlets 11c are provided. The inlet 11 a of the first refrigerant passage 11 communicates with the water pump 15. The water pump 15 is a centrifugal pump driven by the output of the engine. A second refrigerant passage 12 communicates with the first outlet 11b, and the second refrigerant passage 12 communicates with an inlet of the radiator 13. Here, the radiator 13 performs heat exchange between the refrigerant and external air. The outlet of the radiator 13 communicates with the third refrigerant passage 14. The third refrigerant passage 14 connects the outlet of the radiator 13 and the water pump 15. Radiator 13 and water pump 15 in third refrigerant passage 14
A control valve 16 is provided between the control valve and the control valve. Further, the control valve 16 branches from the second refrigerant passage 12 and the second refrigerant passage 12.
And a fourth refrigerant passage 17 that communicates with the second refrigerant passage. Here, the control valve 16 is a thermostat valve that operates in accordance with the temperature of the refrigerant. The control valve 16 controls the flow rate of the second refrigerant passage 12 to communicate with the third refrigerant passage 14 through the radiator 13 and the second refrigerant passage 12 communicates the fourth refrigerant The ratio of the flow rate to be communicated with the third refrigerant passage 14 via the passage 17 is controlled.

On the other hand, the second outlet 11c communicates with the fifth refrigerant passage 18. The fifth refrigerant passage 18 communicates with a sixth refrigerant passage 20 provided in the throttle body 19. Here, the throttle body 19 controls the amount of air taken into the engine. The sixth refrigerant passage 20 warms the throttle body 19 by the refrigerant passing therethrough, and prevents icing (freezing) of a throttle valve (not shown) provided inside the throttle body 19. The sixth refrigerant passage 20 communicates with the third refrigerant passage 14 between the control valve 16 and the water pump 15.
1 and communicate with the third refrigerant passage 14. An eighth refrigerant passage 22 branches off from the fifth refrigerant passage 18, and communicates the inlet of the heater core 23 with the second outlet 11c.
The heater core 23 is a heat exchanger that exchanges heat between the refrigerant and the cabin air. A ninth refrigerant passage 24 is provided at an outlet of the heater core 23. The heater core 23 communicates with the third refrigerant passage 14 between the control valve 16 and the water pump 15 via the ninth refrigerant passage 24.

[0004] The operation of the above-described engine cooling device 10 will be described. In the above-described engine cooling device 10, the control valve 16 opens and closes according to the temperature of the refrigerant, and the flow rate ratio of the refrigerant flow path changes. For example, when the temperature of the refrigerant is low, such as when the engine is cold, the fourth refrigerant passage 17 is controlled by the control valve 16 rather than the refrigerant flowing from the second refrigerant passage 12 to the third refrigerant passage 14 via the radiator 13.
Increase the amount of refrigerant flowing through. Thereby, the water pump 15, the first refrigerant passage 11, the second refrigerant passage 1
2, fourth refrigerant passage 17, control valve 16, third refrigerant passage 14
Is constituted. The first refrigerant circuit bypasses the radiator 13 to circulate the refrigerant. Thereby, the amount of the refrigerant circulating in the refrigerant circuit can be reduced by the amount of the refrigerant remaining in the radiator 13. Further, since the refrigerant does not flow through the radiator 13, the refrigerant is not cooled in the radiator 13. Therefore, the time until the temperature of the refrigerant is increased (the warm-up of the engine is completed) can be shortened. When the temperature of the refrigerant is high, such as when the engine is rotating at a high speed or under a high load, the second refrigerant passage 1
2 increases the amount of refrigerant flowing through the radiator 13 to the third refrigerant passage 14. This allows the water pump 1
5, a second refrigerant circuit including a first refrigerant passage 11, a second refrigerant passage 12, a radiator 13, a control valve 16, and a third refrigerant passage 14 is provided, and the radiator 1
In step 3, heat can be exchanged with external air. As a result,
It is possible to prevent problems such as overheating caused by a temperature rise of the refrigerant equal to or higher than a predetermined temperature and seizure of the engine.

[0005] The heater core 23 from the second outlet 11c through the fifth refrigerant passage 18 and the eighth refrigerant passage 22.
The refrigerant that has flowed through the air exchanges heat between the cabin air and the refrigerant to warm the cabin.

[0006]

By the way, in the above-described engine cooling device 10, when the temperature of the refrigerant is low, a first refrigerant circuit is formed. In the first refrigerant circuit, the temperature of the refrigerant is more likely to rise than in the case where the refrigerant passes through the second refrigerant circuit passing through the radiator 13, but the time for warming the refrigerant (warm-up time) is still long. As is well known, since the engine is a heat engine, it cannot be operated with high efficiency unless the temperature of the refrigerant rises to some extent (about 80 ° C.). In addition, since the heat of the refrigerant is used for heating the air in the passenger compartment, it is desirable that the refrigerant temperature be rapidly increased to some extent.

Therefore, an object of the present invention is to provide a cooling device capable of rapidly increasing the temperature of a refrigerant of an engine.

[0008]

According to the present invention, there is provided a pump for circulating a refrigerant, and a pump for communicating with the pump and provided inside the engine. A first refrigerant passage, a radiator that exchanges heat between the external air and the refrigerant, a second refrigerant passage that communicates the first refrigerant passage with the radiator, a third refrigerant passage that communicates the radiator with the pump means, A fourth refrigerant passage that allows the second refrigerant passage and the third refrigerant passage to communicate with each other without the use of a radiator, and a third refrigerant passage disposed between the radiator and the pump unit. , A control means for communicating with one of the fourth refrigerant passages, the control means being disposed between the control means of the third refrigerant passage and the pump means, and the communication between the control means and the pump means. Is that in which a switching means for controlling the cut-off.

According to the above-mentioned means, the pump means is provided between the control means of the third refrigerant passage and the pump means, and the switching means for switching between the communication and the cutoff between the control means and the pump means is provided. The flow of the refrigerant can be completely stopped irrespective of the operation of. Thereby, the refrigerant in the first refrigerant passage provided in the engine is rapidly heated by the heat generated by the operation of the engine, and the temperature of the refrigerant in the engine can be quickly increased.

According to the second aspect of the present invention, in addition to the first aspect of the present invention, a first refrigerant passage, a third refrigerant passage switching means, and a pump means are provided. And a fifth refrigerant passage which communicates with the first refrigerant passage is provided, and the refrigerant always flows through the fifth refrigerant passage. by this,
The refrigerant can always be supplied to a portion where the circulation of the refrigerant is required.

[0011] Further, the technical means taken in the invention of claim 3 is in addition to the technical means of claim 1 or 2,
That is, a temperature sensor for measuring the temperature of the refrigerant is provided at a portion in contact with the flow in the fifth refrigerant passage. By providing the temperature sensor for measuring the temperature of the refrigerant in the fifth refrigerant passage, the temperature of the refrigerant flowing through the first refrigerant passage can be measured instead of the temperature of the staying refrigerant. As a result, the change in the temperature of the refrigerant can be immediately detected, so that the optimum engine temperature control according to the change in the temperature of the refrigerant can be performed, and the engine can be operated under the optimum temperature condition. In addition to the above, it is possible to prevent the occurrence of troubles due to a rise in the refrigerant temperature, such as overheating and burning of the engine.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a first embodiment of the present invention. In the cooling device 110 of this embodiment,
A control valve 116 and a switching valve (switching means) 130 are provided in the third refrigerant passage 114, respectively. The fifth refrigerant passage 121 is located between the switching valve 130 of the third refrigerant passage 114 and the water pump (pump means) 115, and the ninth refrigerant passage 124 is located between the control valve 116 of the third refrigerant passage 114 and the switching valve 130, respectively. Note that other configurations are the same as those of the cooling device 10 shown in FIG.

Switching valve 1 provided in third refrigerant passage 114
Numeral 30 has a valve element driven by a signal from an engine control unit (hereinafter referred to as ECU) 200, for example, driven by a solenoid, a motor, or the like, depending on the temperature of the refrigerant in the engine. It is. Here, the ECU 200 operates the engine based on information from a throttle opening sensor 210 for measuring the engine load, an engine speed sensor 220 for measuring the engine speed, and an intake air amount sensor 230 for measuring the intake air amount. The fuel injection amount and the like are controlled so as to obtain an output according to.

The fifth refrigerant passage 122 is connected to the second outlet 1
11c communicates with a sixth refrigerant passage (fifth refrigerant passage) 119 formed inside the throttle body 123. Sixth
The refrigerant passage 118 is a seventh refrigerant passage (fifth refrigerant passage) 121.
Through the third refrigerant passage 114 between the switching valve 130 and the water pump 115. A water temperature sensor 140 is attached to the fifth refrigerant passage 122. The first refrigerant passage 111, the fifth refrigerant passage 118, and the sixth refrigerant passage 12
A circuit that reaches the third refrigerant passage 114 via the zero and seventh refrigerant passages 121 is referred to as a third refrigerant circuit. In the present embodiment, the third refrigerant circuit requires a refrigerant flow from a low refrigerant temperature, such as an icing prevention passage for warming the throttle body 119, and the required passage volume is small. It is.

From the fifth refrigerant passage 118, the seventh refrigerant passage 1
22 is provided in a branched manner. The seventh refrigerant passage 122 communicates the second outlet 111c with the heater core 123. The heater core 123 communicates with the third refrigerant passage 114 via a ninth refrigerant passage 124 that communicates between the control valve (control means) 116 and the switching valve (switching means) 130 of the third refrigerant passage 114. This circuit is called a fourth refrigerant circuit.

Next, the operation will be described. When the engine is cold, the switching valve 130 shuts off the third refrigerant passage 114 by a signal from the ECU 200. Therefore, the refrigerant discharged from the water pump 115 flows from the first refrigerant passage 111 to the fifth refrigerant passage 118. Fifth refrigerant passage 118
Is connected to the third refrigerant passage 114 between the switching valve 130 and the water pump 115, and the ninth refrigerant passage 124 is connected to the third refrigerant passage 114 between the control valve 116 and the switching valve 130. are doing. Therefore, the refrigerant flows to the third refrigerant circuit. Since the amount of the refrigerant that can flow to the third refrigerant circuit is small as described above, the amount of heat radiation in the middle of the cooling circuit can be reduced. Also, by stopping the circulation of the refrigerant in the first, second, and fourth refrigerant circuits,
The total amount of the refrigerant can be reduced, and the heat radiation due to heat exchange between the external air and the refrigerant can be reduced. Thus, heat generated by the operation of the engine can be efficiently transmitted to the refrigerant, and the refrigerant can be rapidly warmed. The warmed refrigerant circulates through the third refrigerant circuit, and its temperature is measured by a temperature sensor 140 provided in the fifth refrigerant passage 118. Since this refrigerant is the refrigerant that has passed through the first refrigerant passage 111, the current temperature of the engine can be measured more accurately. As a result, it is possible to adjust the optimal fuel injection amount, injection timing, and ignition timing according to the engine temperature. Also, it can be detected whether the temperature of the refrigerant in the first refrigerant passage 111 has risen more than necessary according to the temperature of the refrigerant.
If the temperature of the refrigerant is equal to or higher than the predetermined temperature, the switching valve 130 can be switched to the open state to circulate the refrigerant in the second circuit or the first circuit. As a result, the temperature of the refrigerant can be immediately increased to an optimum condition for the operation of the engine, the refrigerant can be cooled as necessary, and the occurrence of a trouble caused by the increase in the temperature of the refrigerant can be prevented.

[0017]

As described above, according to the first aspect of the present invention,
By providing a second switching valve arranged in the third refrigerant passage between the control valve and the water pump and controlling the communication and shutoff between the control valve and the water pump, the refrigerant can be supplied regardless of the operation of the water pump. The flow can be stopped completely. As a result, the first
The refrigerant in the refrigerant passage can be quickly heated by heat generated by the operation of the engine. If the refrigerant is supplied to each part of the engine after being sufficiently warmed, the time until the warm-up of the engine is completed can be shortened. Until the warm-up of the engine is completed, it is an area where the efficiency of the engine is low,
Reducing the warm-up completion time will contribute to improving engine efficiency.

According to the second aspect of the present invention, in addition to the first aspect, the second switching valve and the water pump of the first refrigerant passage and the third refrigerant passage are provided. A fifth refrigerant passage is provided to communicate with the space, and the refrigerant always flows in the fifth refrigerant passage, so that a small amount of refrigerant circulation is always required to prevent icing of the throttle valve and the like. Can be supplied with a refrigerant.

The technical measures taken in the third aspect of the present invention are the same as those of the first or second aspect.
By providing a temperature sensor for measuring the temperature of the refrigerant at a position in contact with the flow in the fifth refrigerant passage, the temperature of the refrigerant flowing through the first refrigerant passage can be measured. This makes it possible to accurately know the temperature of the refrigerant in the first refrigerant passage, control the operation of the engine to optimal conditions according to the temperature, and prevent problems such as occurrence of overheating due to a rise in the temperature of the refrigerant. Can be.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a conventional engine cooling device.

FIG. 2 is a conceptual diagram showing an embodiment of the present invention.

[Explanation of symbols]

 10, 110 Cooling device 11, 111 First refrigerant passage 12, 112 Second refrigerant passage 13, 113 Radiator 14, 114 Third refrigerant passage 15, 115 Pump means, 16, 116 Control means 17, 117 Fourth refrigerant passage 18 , 118 Fifth refrigerant passage 130 Switching means 140 Temperature sensor

Claims (3)

[Claims] 1. A pump means for circulating a refrigerant, a first refrigerant passage provided in the engine in communication with the pump means, a radiator for exchanging heat between external air and the refrigerant, and a radiator for the first refrigerant passage. A third refrigerant passage communicating the radiator and the pump means; a fourth refrigerant passage communicating the second refrigerant passage with the third refrigerant passage without passing through the radiator; A control unit disposed between the radiator of the refrigerant passage and the pump unit, the control unit causing the third refrigerant passage to communicate with the second refrigerant passage or the fourth refrigerant passage. Disposed between the control means and the pump means,
A cooling device for an engine, comprising switching means for controlling communication / shutoff between the control means and the pump means. 2. A fifth refrigerant passage which communicates between the first refrigerant passage, the switching means for the third refrigerant passage, and the pump means, wherein the refrigerant always flows through the fifth refrigerant passage. The engine cooling device according to claim 1, wherein: 3. A temperature sensor for measuring the temperature of the refrigerant is provided by a fifth sensor.
The engine cooling device according to claim 1, wherein the cooling device is provided at a portion that comes into contact with the flow in the refrigerant passage.