JPS62271930A - Intake air cooling device for internal combustion engine - Google Patents

Abstract

PURPOSE:To achieve the enhancement in the cooling effect of intake air in a prescribed operating region by providing an intake air cooling device in the bypass passage of an intake pipe, and providing a changeover valve on the upstream side thereof so that it can be changed over in response to the relationship between the temperature of the cooling device and that of intake air to heighten the cold storage effect. CONSTITUTION:An intake air cooling device 22 is provided in the bypass passage 5 of an intake pipe 3, and a changeover valve 7 is provided at the branch part of the bypass passage 5. Temperature sensors 56 and 57 are provided on the intake pipe 3 and the cooling device 22 respectively, and the signals from both sensors are input into a transistor 62 via a comparator 60 to open or close an electromagnetic open/close valve 39. When the intake temperature is higher than the temperature of the cooling device, the open/close valve 39 is opened, and the negative pressure at the negative pressure port 2a is introduced into an actuator 8 to change over the changeover valve 7, so that intake air is introduced into the bypass passage 5 to cool the intake air. When the intake temperature is lower, the changeover valve 7 is closed to cool the cold storage medium in the cooling device.

Description

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

[Conventional technology]

Cooling the intake air in an internal combustion engine lowers the air density, increases charging efficiency, and is expected to increase output.

As an intake air cooling device, one has been proposed that stores cold in a heat exchange section during normal operation and releases the cooled air during acceleration (see Japanese Patent Laid-Open No. 60-43123).

In this conventional technology, a cold storage layer is formed around a heat exchange unit that cools intake air, and the intake air is cooled by storing cold during normal operation and releasing it during necessary operation.

[Problem that the invention seeks to solve]

Conventionally, the intake air cooling device is installed in the engine intake pipe itself. Therefore, the intake air is constantly in contact with the intake air cooling device. As a result, the intake air is cooled even during non-necessary operation, leading to insufficient cold storage and insufficient cooling performance during acceleration, which requires cooling.

Therefore, in order to solve this problem, the present applicant installed an intake air cooling device equipped with a cold storage means in a bypass passage that bypasses the intake pipe, and during normal times, the bypass is closed to store cold, and when accelerating, the We are proposing an improvement in which the intake air is cooled by a cooling device that stores cold by opening the air.

It is an object of the present invention to provide such an improved technique so that bypass control can be performed in accordance with the amount of cool storage.

[Means for solving problems]

According to the present invention, a vehicle internal combustion engine equipped with an air conditioner is provided with a bypass passage that bypasses an intake pipe of the internal combustion engine, an intake air cooling device is disposed in the bypass passage, and the intake air cooling device is connected to the air conditioner. It consists of a heat exchange tube through which the cooling medium from the refrigerant circulation passage circulates, a cold storage means arranged around the nuclear heat exchange tube, and a valve means for controlling the detour of the intake air to the bypass passage, and a cooling means for controlling the detour of the intake air to the bypass passage. a first control means for controlling the valve means to open the bypass passage during a predetermined operation of the engine requiring cooling; a means for detecting a temperature difference between the intake air temperature and the temperature of the cool storage means; An intake air cooling device for an internal combustion engine is provided, comprising a second control means for restricting the valve means to a closed state in response to a temperature difference.

〔Example〕

In FIG. 1, the internal combustion engine includes an engine body 1, a surge tank 2, an intake pipe 3, and a throttle valve 4. intake pipe 3
A bypass passage 5 is provided to bypass the. The switching valve 7 is at a position where the intake air passes through the intake pipe 3 as indicated by the arrow f,
or the position where the bypass passage 5 is allowed to pass as shown in g. The switching valve 7 is of a swing door type and is connected to a diaphragm actuator 8. The diaphragm actuator 8 consists of a diaphragm 8a connected to the switching valve 7 and a spring 8b.

The air conditioner cooling system for cooling the vehicle interior includes a compressor 12, a condenser 14, an expansion valve 16, and an evaporator 18.
These elements are interconnected by a refrigerant circulation pipe 20. As is well known, the refrigerant compressed by the compressor 12 is condensed and liquefied in the condenser 14, expanded in the expansion valve 16, and vaporized in the evaporator 18. This vaporization removes heat and cools the vehicle interior. .

According to this invention, the intake air cooling device 22 is disposed in the bypass passage 5, and this device 22 stores cold during normal operation when the switching valve 7 closes the bypass passage 5.
The intake air passing through the bypass passage 5 is cooled during operations that require intake air cooling, such as during acceleration when the bypass passage 5 is opened. As shown in FIG. 2, the intake air cooling device includes a casing 24 constituting a part of the bypass passage 5, an evaporator pipe 26 as a heat exchange pipe arranged in a meandering manner in the casing, and an arrangement around the evaporator pipe 26. A cold storage material holder 28 and fins 3 formed around the cold storage material holder 28.
It consists of 0 and 0. The cold storage body holder 28 is filled with a cold storage material (for example, water) that is a material with high specific heat. The wick 32 can be impregnated with the cold storage material. The periphery of the casing 24 is covered with a heat insulating material 34. The evaporator pipe 26 forms a refrigerant inlet portion 26a and an outlet portion 26b, and as shown in FIG.
The outlet section 26b is connected to the air conditioner refrigerant pipe downstream of the condenser 14 through the outlet section 26b, and the outlet section 26b is connected upstream of the compressor 12. Therefore, the air conditioner refrigerant is branched and recirculated within the evaporator pipe 26, and the cold storage material can be kept cold.

In order to perform cold storage and cooling control according to engine operating conditions, the space below the diaphragm 8a is connected to the negative pressure outlet port 2a of the surge tank 2 via a negative pressure passage 37.

A check valve 38 is installed in the middle, and an electromagnetic on-off valve 39 is connected to the negative pressure passage 37 so as to bypass the check valve 38.

In FIG. 1, reference numeral 40 indicates a control circuit for controlling the air conditioner combination 12. As shown in FIG.

The control circuit 40 includes a well-known air conditioner control circuit 41, which generates an operating signal for the compressor 12 in response to the air conditioner refrigerant temperature and pressure. The control circuit 41 is an AND
A switch 43 is connected to one input of the gate 42 and installed at the other input, and this switch 43 has a position sensor section 43a of the switching valve 7, and the switching valve 7 is connected to the bypass 5.
The compressor 12 is stopped when the compressor 12 is positioned to open the compressor 12, that is, when cooling the intake air.

The output of AND gate 42 is empty Am h compressor 12
It is connected to a transistor 54 for driving the operating solenoid 12a.

゛ An intake air temperature sensor 56 is installed in the intake pipe 3,
A signal corresponding to the intake air temperature T+ is obtained. Cooling device 2
2 is provided with a temperature sensor 57, and a signal corresponding to the temperature T2 of the cold storage material is obtained. These sensors 56, 57 are connected to a comparator 60. Comparator 60 generates a logic signal according to the difference between the intake air temperature and the regenerator material temperature. For example, T
Generates a “1” signal when I > T2, and generates a “1” signal when T1 ≦T
When it is 2, a signal of "0" is generated. The output of the comparator 60 is connected to the driving transistor 62 of the solenoid 39a of the electromagnetic on-off valve 39.

To explain the operation of the embodiment described above, when the intake air can be cooled by the cooling device 22, the intake air temperature Tl
:>T2. At this time, since a signal of "1" is output from the comparator 60, the transistor 62 is turned on, the solenoid 39a is energized, and the on-off valve 39 is opened. When the on-off valve 39 is open, it is the same as if the check valve 38 is not present, and the diaphragm actuator 8 controls the switching valve 7 by the negative pressure of the negative pressure port 2a of the surge tank 2. At low load with a small opening of the throttle valve 4, the negative pressure at the negative pressure outlet port 2a becomes strong, so the diaphragm 8a
is lowered against the spring 8a, and the switching valve 7 closes the bypass passage 5. Therefore, intake air is supplied to the engine via the intake pipe 3 as indicated by arrow f. On the other hand, the switching valve 7
When the bypass 5 is closed, the switch 43 is OFF.
Therefore, the air conditioner operation signal from the air conditioner control circuit 41 is applied to the air conditioner compressor drive transistor 54 via the AND gate 42, and the compressor 12 is rotationally driven in accordance with the signal. And compressor 1
The cooling medium from 2 is condensed in the condenser 14, after which a portion is branched off to the expansion valve 36, where it is expanded and enters the evaporator tube 26 of the intake air cooling device 22, where it is vaporized. 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 28 around the evaporator pipe 26. become.

When the engine is under high load, the negative pressure at the port 2a weakens, the diaphragm 8a is displaced upward by the spring 8b, 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. When the switching valve 7 assumes the bypass open position, the switch 43 is turned ON, and the gate 42 turns the transistor 54 OFF, so that the compressor 1
2 is stopped. Therefore, since the engine load is reduced by the amount of the compressor, good acceleration operation is 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 cooling device 20. Since the duration of acceleration is short, the amount of cold storage 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.

During operation in which acceleration and deceleration are frequently repeated, the amount of cool storage is insufficient, and sufficient cooling by the cooling device 22 cannot be obtained. In this embodiment, such a state occurs when the intake air temperature TI<T
I consider it to be 2. At this time, the comparator 60 generates a signal of ``05'', so the transistor 62 is turned off, the solenoid 39a is demagnetized, and the on-off valve 39 is closed. The negative pressure generated at the negative pressure outlet port 2a acts on the diaphragm 8a, displacing the diaphragm downward against the spring 8b, and forcing the switching valve 7 to close the bypass passage 5.The opening degree of the throttle valve 4 is large. At this time, the negative pressure in the port 2a is insufficient to lower the diaphragm 8a (but the opening/closing valve 39 is in the closed state), so the diaphragm 8a bypasses the switching valve 7 due to the check valve 38. It is maintained in the closed state.Therefore, regardless of the load, intake air is introduced into the engine through the intake pipe 3 as shown by arrow f.When the temperature of the cool storage material is high, the intake air is transferred to the cooling device 22.
Naturally, even if the air conditioner is passed through the air conditioner, sufficient cooling cannot be achieved, and the air conditioner compressor is always in operation, resulting in a decrease in output, but this problem can be solved.

In the modified example shown in FIG. 2, the thermal enclosure is 57A.

57B, and the detected value is sent to the averaging circuit 7.
0, and control is performed based on the magnitude of this average value and the intake air temperature. By calculating the average temperature, the difference from the intake air temperature can be accurately detected.

In the embodiment, control is performed by determining whether or not the intake air temperature T1≧cool storage material temperature T2, but these temperature differences can be set appropriately, thereby freely changing the intake air cooling characteristics. becomes possible.

〔effect〕

According to this invention, the intake air is cooled only when there is sufficient cold storage in the cooling system, and the air is bypassed when intake air cooling cannot be expected, thereby reducing pressure loss and increasing engine output. be able to.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a first embodiment of the present invention. FIG. 2 is an enlarged sectional view of the cooling device. 3...Intake pipe 5...Bypass passage 7...Switching valve 8...actuator 12...Compressor 22...Cooling device 26... Evaporator pipe 28...Cold storage material holder 38...Check valve 39...Solenoid on-off valve 40...control circuit 41...Air conditioner control circuit 56...Intake air temperature sensor 57...Cold storage material temperature sensor 60...Comparator

Claims (1)

[Claims] A vehicle internal combustion engine equipped with an air conditioner is provided with a bypass passage that bypasses the intake pipe of the internal combustion engine, and an intake air cooling device is disposed in the bypass passage, and the intake air cooling device receives cooling from the air conditioner refrigerant circulation passage. a heat exchange tube in which a medium circulates;
a cold storage means disposed around the heat exchange pipe, and a valve means for controlling detour of the intake air to the bypass passage; and a valve means for controlling the detour of the intake air to the bypass passage; a first control means for controlling the valve means to open; means for detecting a temperature difference between the intake air temperature and the temperature of the cold storage means; and a second control means for restraining the valve means in a closed state in response to the temperature difference. An intake air cooling device for an internal combustion engine, characterized in that it has a control means.