JPS62271928A - Intake air temperature control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To carry out efficiently the heating of intake air and the cooling of intake air by a common system, by connecting two heat exchangers, each of which carries out the heat exchange with intake air and outside air respectively, to a compressor via two changeover valves so as to change over these values in response to the temperature of an engine. CONSTITUTION:The first heat exchanger 13 is provided in the bypass passage 5 which bypasses an intake pipe 3, and the second heat exchanger 14 is provided so as to be capable of exchanging heat with outside air. These two heat exchangers 13 and 14 are connected to a compressor 12 via two four-way solenoid valves 16, 18. And both valves 16, 18 are changed over in response to the temperature of an engine. When the engine temperature is low, the coolant compressed through the compressor 12 circulates passing through a heat exchanger 13 as a condenser and a heat exchanger 14 as an evaporator to heat intake air. When the engine temperature is high, the coolant is circulated in the reverse direction by changing over the valves 16, 18 to cool intake air.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an apparatus for heating and cooling intake air using a cooling medium of an air conditioner.

[Conventional technology]

In an internal combustion engine, when the engine temperature is low, intake air is heated to improve engine performance.

Some intake air heating devices utilize engine exhaust gas or heat intake air using electric heater means.

On the other hand, during accelerated operation after warm-up, the intake air is cooled to lower air density, increase charging efficiency, and increase output. An air-cooled or water-cooled inktorer may be installed to cool the intake air.

[Problem that the invention seeks to solve]

Conventionally, separate means were installed for heating the intake air when the engine is cold and for cooling the intake air after the engine warms up. Therefore, there was a problem that the structure of the engine intake system was complicated.

An object of the present invention is to use a structure similar to that of a heat pump that is used for both cooling and heating in an air conditioner for a home to heat and cool intake air.

[Means for solving problems]

According to this invention, in a vehicle internal combustion engine, a compressor, a first heat exchanger, a second heat exchanger, a first switching valve, a second switching valve, and a first switching valve are provided. and a control means for driving the second switching valve according to the temperature condition of the engine, the first heat exchanger is arranged so as to be able to exchange heat with the intake air in the intake pipe of the engine, The heat exchanger is arranged to be able to exchange heat with outside air, and the control means constitutes a first circulation system from the compressor to the compressor via the first heat exchanger, the second heat exchanger and back under low temperature conditions; There is provided an intake air temperature control device for an internal combustion engine, characterized in that under high temperature conditions, a second circulation system is configured from the compressor, via the second heat exchanger, the first heat exchanger, and back to the compressor.

[Function] At low temperatures, the first heat exchanger placed in the intake pipe functions as a condenser, and the second heat exchanger placed in the outside air functions as an evaporator, heating the intake air.

When the temperature is high, the second heat exchanger placed in the outside air functions as a condenser, and the first heat exchanger installed in the intake pipe functions as an evaporator, thereby cooling the intake air.

〔Example〕

In FIG. 1, the internal combustion engine includes an engine main body IJ surge tank 2, an intake pipe 3, and a throttle/nottle valve 4. A bypass passage 5 that bypasses the intake pipe 3 is provided. The electromagnetic switching valve 7 is configured to switch between a position where the intake air passes through the intake pipe 3 as shown by an arrow f, or a position where the intake air passes through the bypass passage 5 as shown by the arrow g. The switching valve 7 controls the opening and closing of the bypass passage 5 according to temperature conditions by a control circuit to be described later.

9 is a radiator for engine cooling water;
It is connected to the cooling water circulation passage 10.

A well-known thermostat (temperature valve) is installed in the cooling water circulation passage 10.
11 is arranged, and the cooling water flows through the bypass passage 11a when the temperature is low.
It is branched into.

According to this invention, the device for heating and cooling intake air is provided to also serve as a cooling system for the vehicle interior. That is, this system includes a compressor 12, a first heat exchanger 13, a second heat exchanger 14, a first four-way switching valve 16, a second four-way switching valve 18, and an on-off valve. 20 and
It is composed of a first expansion valve 22, a heat exchanger (evaporator) 24 for the passenger compartment, an on-off valve 26, and a second expansion valve 28. The compressor 12 is connected to the crankshaft 1a of the engine by a connecting means 29 such as a belt, and is rotationally driven to compress the refrigerant. The first heat exchanger 13 is arranged in a bypass passage 5 that bypasses the intake pipe 3. Second
The heat exchanger 14 is installed in front of the engine radiator 9. The first switching valve 16 and the second switching valve 18 constitute a circulation system from the compressor 12, through the second heat exchanger 14, then through the first heat exchanger 13, and back to the compressor 12, as shown in FIG. When the intake air is cooled, as shown in FIG.
This is to change the heating state of the intake air that constitutes the circulation system that returns to the compressor 12 via the heat exchanger 14.

In the intake air cooling state shown in Fig. 1, the heat exchanger 24 for cooling the passenger compartment
The upstream side is via the expansion valve 22, and the downstream side is via the electromagnetic on-off valve 2.
6 to the refrigerant circulation system in front of the compressor 12, making it possible to cool the passenger compartment. On the other hand, in the intake air heating state shown in FIG. 2, the electromagnetic on-off valve 26 is closed, so that no refrigerant flows into the heat exchanger 24 for the passenger compartment.

The first heat exchanger 13 is installed in a bypass passage 5 that bypasses the intake pipe 3, and heats the intake air during cold periods and cools it during acceleration after warming up. It also has the function of storing cold during normal operation after warming up and improving cooling performance during acceleration. As shown in FIG. 3, the first heat exchanger 13 includes a casing 32 constituting a part of the bypass passage 5, a heat exchange pipe 33 meanderingly arranged in the casing, and a heat exchange pipe 33 arranged in a meandering manner in the casing.
, and fins 35 formed around the cool storage material holder 34 .

The cold storage material holder 34 contains a cold storage material (
e.g. water).

The wick 36 can be impregnated with the cold storage material.

The periphery of the casing 32 is covered with a heat insulating material 37.

The heat exchange tube 33 forms a refrigerant inlet part 33a and an outlet part 33b, and as shown in FIG. 1, an expansion valve 28 is disposed in front of the artificial part 33a.

In order to control the heating and cooling of the intake air according to the operating conditions of the engine, an electronic control circuit 40 is provided, which determines the operating conditions based on the signals from each sensor,
8 and the on-off valve 26 between the state shown in FIG. 1 and the state shown in FIG. 2. An intake pipe pressure sensor 42 is installed in the surge tank 2 and generates a signal depending on the intake pipe pressure. The pressure sensor 44 is connected to a comparator 44, which outputs a "1" signal when the intake pipe pressure is lower than a predetermined value P0 (during high load) and a "0" signal when it is lower than the predetermined value (during low load). occurs.

An engine coolant temperature sensor 46 is arranged in the engine coolant pipe 10 upstream of the thermostat 11. The water temperature sensor 46 is connected to a comparator 48, and the comparator 48 indicates that the water temperature is a predetermined value THW. A signal of “0” when higher than the predetermined value T
Generates a "1" signal when the voltage is lower than H-0. An intake air temperature sensor 50 is installed in the intake pipe and connected to a comparator 52. When the intake air temperature is higher than a predetermined value T A o, the comparator 52 outputs an "O" signal, and when it is lower, it outputs a "1" signal. is starting to occur. Comparator 48.52 is O
Connected to R gate 54. The output of the OR gate 54 is
Solenoid 16a of switching valve 16.18 and on-off valve 26,
Connected to drive transistors 56, 68, 60 of 18a, 26a. Additionally, the OR gate 54 and the comparator 44 are
The output of the OR gate 62 is connected to the driving transistor 64 of the solenoid 7a of the switching valve 7.

Reference numeral 70 denotes a well-known air conditioner control circuit, which forms an air conditioner operation signal according to the air conditioner refrigerant temperature and pressure. The air conditioner control circuit 70 connects the solenoid 12 of the actuating clutch (not shown) of the compressor 12 via an AND gate 72.
It is connected to the drive transistor 74 of a. And A
The output of OR gate 62 is connected to the inverting input of ND gate 72 .

To explain the operation of the configuration of the present invention described above, when the engine is at a low temperature, the comparator 4 or the comparator 52 generates a "1" signal, so the OR gate 54 is connected to the transistor 56.
58.60 as ONL, switching valve 16.18 and on/off valve 26
solenoid 16a.

18a and 26a are excited to take the state shown in FIG. Then, when the OR gate 54 is turned on, the OR gate 62 is turned on, the transistor 64 excites the solenoid 7a, the switching valve 7 opens the bypass 5, and the intake air flows as indicated by the arrow g in FIG.

In FIG. 2, the compressed refrigerant from the compressor 12 forms a circuit back to the compressor 12 through a first heat exchanger 13 acting as a condenser and then through a second heat exchanger 14 acting as an evaporator. Since the cold intake air is passing through the bypass passage 5 where the first heat exchanger 13 is arranged, the refrigerant condenses and releases heat, thereby heating the intake air passing through the surrounding bypass passage 5.

The refrigerant that has heated the intake air passes through the expansion valve 28 and evaporates in the heat exchanger 14 of the cylinder 2, and is then transferred to the compressor 1.
2, and by repeating the above cycle, intake air heating at low temperatures is performed. At this low temperature, the on-off valve 26 is closed, so no refrigerant is supplied to the heat exchanger 24 for the passenger compartment. Note that the on-off valve 26 does not necessarily need to be installed, and only the expansion valve 22 can be used.

After the engine is warmed up, the comparators 48, 52 output a signal of "0", so the OR gate 54 generates an output of "O", the transistors 56, 58, 60 turn off, and the solenoids 16a, 18a and 26a are demagnetized, and the switching valves 16 and 18 and the on-off valve 26 assume the positions shown in FIG. That is, the refrigerant from the compressor 12 first passes through the second heat exchanger 14, then returns to the compressor 12 via the first heat exchanger 13, forming a circulation system. At low load when the opening of the throttle valve 4 is small, the comparator 44 is “0”.
”, the OR gate 62 generates an output of “0” and the solenoid 7a is demagnetized. Therefore, the switching valve 7 closes the bypass passage 7. Therefore, the intake air flows as indicated by the arrow f. is supplied to the engine via the intake pipe 3. On the other hand, the inverting input of the AND gate 72 is supplied with "
Since a signal of 0'' is input, the air conditioner operation signal from the air conditioner control circuit 41 is applied to the air conditioner compressor drive transistor 74 via the AND gate 72, and the compressor 12 is rotationally driven in accordance with the signal.

The cooling medium from the compressor 12 is condensed in the second heat exchanger 14 which acts as a condenser, and then a part is branched to the expansion valve 28 where it is expanded and transferred to the second heat exchanger 13 which acts as an evaporator. enters the heat exchange tube 33,
vaporize here. Heat is removed by vaporization.

During partial load, the intake air does not pass through the bypass passage 5, so no heat exchange takes place, and the heat taken away by vaporization is retained in the cool storage material in the holder 34 around the heat exchange tube 33. become.

When the engine is under high load, the comparator 44 outputs a signal of "1", so the OR gate 62 is turned on, the transistor 64 excites the solenoid 7a, and the switching valve 7 opens the bypass passage 5. Therefore, intake air is introduced into the bypass passage 5 as indicated by arrow g. On the other hand, since the OR gate 62 is turned on, the AND gate 72 is turned off, and the transistor 74 is turned off, so the compressor 12 is stopped. Therefore, since the engine load is reduced by the amount of the compressor, good acceleration operation can be achieved. Even if the compressor 12 is stopped, the intake air is efficiently cooled by heat conduction from the liquid (or solid) stored in the heat exchanger 13.

Since the m-duration of acceleration is short, the amount of cold stored in the cold storage material is not insufficient to obtain the desired cooling performance. Good cooling is achieved, resulting in increased charging efficiency and increased engine output.

FIG. 4 is a timing chart showing the operation of the invention described above. At low temperatures, the four-way switching valve 16.18 is activated,
The state shown in FIG. 2 is taken, the switching valve 7 opens the bypass, and the first heat exchanger 13 heats the intake air. Time t
1 is the acceleration point, but the intake air heating state is maintained. After warming up, the four-way solenoid valves (16, 18) assume the state shown in FIG. 1 in which they are demagnetized.

Under normal load conditions, the switching valve 7 closes the bypass 5 and the first heat exchanger 13 stores cold. If the acceleration operation is started at time t2, the switching valve 7 opens the bypass 5, cooling of the intake air is performed by the first heat exchanger 13, and at the same time, the air conditioner compressor 12 is stopped.

〔effect〕

According to this invention, a common system can perform intake air heating during warm-up when the intake air temperature is low or water temperature is low, and intake air cooling after warm-up, especially during acceleration operation,
An economical and efficient system can be constructed.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, showing the state when cooling intake air. FIG. 2 shows only the main parts of the present invention in FIG. 1, and shows the case where intake air is heated. FIG. 3 is an enlarged sectional view of the cooling device. FIG. 4 is a diagram illustrating the operation timing of the embodiment of the present invention. 3...Intake pipe 5...Bypass passage 7...Switching valve 12...Compressor 13...First heat exchanger 14...Second heat exchanger 16.19...4 Solenoid valve 26...Solenoid on/off valve 40...Control circuit 42...Pressure sensor 46...Water temperature sensor 50...Intake air temperature sensor

Claims (1)

[Claims] In a vehicle internal combustion engine, a compressor, a first heat exchanger, a second heat exchanger, a first switching valve, a second switching valve, a first switching valve, and a second switching valve. the first heat exchanger is arranged to be able to exchange heat with the intake air in the intake pipe of the engine, while the second heat exchanger is arranged to be able to exchange heat with the outside air. The control means is arranged to allow heat exchange, and the control means constitutes a first circulation system from the compressor to the compressor via the first heat exchanger and the second heat exchanger under low temperature conditions, and constitutes a first circulation system from the compressor to the second heat exchanger under high temperature conditions. An intake air temperature control device for an internal combustion engine, comprising a heat exchanger, and a second circulation system that returns to the compressor via the first heat exchanger.