JPS6312826A - Intake air cooling device for internal combustion engine - Google Patents

Abstract

PURPOSE:To perform simple and efficient cooling of intake air, by a method wherein cooling water in a cooling water container is cooled by means of an air conditioner refrigerant, by means of the cooling water, intake air is cooled, and the cooling water is circulated with the aid of a pump run integrally with a mechanical type supercharger. CONSTITUTION:A water-cooled intake air cooling device 26 is situated in a suction pipe 4 located down a line from a mechanical super charger 7. In this case, a cooling water container 31, through which cooling water from a cooling device 26 is circulated, is situated, an air conditioner refrigerant is circulated through a heat exchange part 34 to cool cooling water. The cooling water container 31 is coupled to a circulating pump 36 through a cooling water passage 35 to form a circulating system for cooling water, and the circulating pump 36 is driven by means of the supercharger 7. This constitution cools the cooling water in the cooling water container 31 by means of the air conditioner refrigerant, and intake air in the suction pipe 4 is cooled by means of the cooling water. The cooling water is circulated with the aid of the circulating pump 36 driven by the mechanical type supercharger 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intake air cooling device for a vehicle internal combustion engine equipped with an air conditioner and equipped with a supercharger.

[Conventional technology]

In an internal combustion engine equipped with a supercharger, an intake air cooling device (so-called intercooler) is installed in order to lower the temperature of air that has increased due to adiabatic compression due to supercharging and increase output.

Water-cooled intercoolers are not effective enough in the summer when the outside temperature is high.

Furthermore, the temperature of water, which is a cooling medium, cannot be sufficiently lowered due to the heat in the engine room, and the engine performance is not yet fully demonstrated during high supercharging. Furthermore, the intercooler's cooling capacity fluctuates due to fluctuations in the outside temperature and the heat inside the engine compartment, making it difficult to achieve stable engine performance.

In order to solve this problem, Japanese Patent Publication No. 60-35530 proposes a system in which a surge tank cooling device is attached to the intake pipe, which is branched from the air conditioner for cooling the passenger compartment and operates independently of the air conditioner. ing. That is, the air from the supercharger is strongly cooled by a low-temperature cooling medium branched from the air conditioner. The engine also includes a control circuit that detects the temperature of the intake air and operates the surge tank cooling device when the temperature exceeds a predetermined value. Other related conventional techniques include Utility Model Application Publication No. 59-91421.

[Problem that the invention seeks to solve]

In the prior art, the idea is to simply connect the refrigerant passage of the air conditioner for cooling the passenger compartment to the intake pipe and exchange heat with the intake air. Therefore, in order to sufficiently cool both the interior of the vehicle and the intake air, the cooling capacity of the cooling device must be increased. That is, in the conventional method,
It is necessary to have a cooling capacity equal to the sum of the maximum conductor cooling requirement and the maximum intake air cooling requirement.

The purpose of this invention is to solve the above-mentioned drawbacks of the prior art,
To provide sufficient cooling even though the capacity of a cooling device is limited.

[Means for solving problems]

According to this invention, in an internal combustion engine for a vehicle equipped with an air conditioner, in which a mechanical supercharger is installed in the intake pipe and a water-cooled intake air cooling device is arranged downstream of the supercharger, an independent cooling water container is provided. , an intake pipe from the supercharger and a cooling medium passage branched from the air conditioner are installed so as to be able to exchange heat with the cooling water container, and the intake air is cooled by the cooling water in the cooling water container cooled by the air conditioner cooling medium. There is provided an intake air cooling system for an internal combustion engine, characterized in that cooling is performed and cooling water is circulated by a pump driven together with the rotation of a mechanical supercharger.

〔Example〕

In FIG. 1, ■ is the main body of the internal combustion engine, 2 is an intake manifold, 3 is an exhaust manifold, 4 is an intake pipe, 5 is a throttle valve linked to an accelerator pedal (not shown), and 6 is an air flow meter. 7 is a mechanical supercharger, which is installed downstream of the throttle valve 5. The mechanical supercharger 7 is configured, for example, as a Roots pump, and supercharging is achieved by compressing intake air by rotating a plurality of rotors 7a (Fig. 2) while maintaining a small gap with respect to the housing 7b. It will be done. The gear 7e in the gear housing 7d rotates the pair of rotors 7a in opposite directions. A pulley 10 with a clutch is installed on one rotating shaft 8 of the rotor 7a,
This pulley lO is connected by a belt 12 to a pulley 16 on the crankshaft. When the clutch portion of the pulley 10 engages at high speed and under high load, the rotation of the crankshaft is caused by the pulley 16,
It is transmitted to the rotor 7a via the belt 12 and pulley 10, and supercharging is performed.

In FIG. 1, a bypass passage 18 is connected to the intake manifold 2 at one end and to the intake pipe 4 at the other end so as to bypass the supercharger 7. A bypass control valve 20 is provided in the bypass passage passage 18.
will be installed. This bypass control valve 20 is driven by a negative pressure actuator 22. That is, the negative pressure actuator 22 is connected to the pressure take-off boat 24 of the intake manifold 2, and drives the bypass control valve 20 according to the intake pipe pressure. That is, when the load is low, the pressure in the boat 24 is low, so the actuator 20 opens the bypass control valve 20 by negative pressure action, and a part of the intake air is branched to the bypass passage 1, and the air is supercharged by the supercharger 7. The effect is weakened. on the other hand,
When the load is high, the pressure in the boat 24 becomes high, so the actuator 22 closes the bypass control valve 20, and the intake air is fully supplied to the combustion chamber 2 via the supercharger 7, and the supercharger 7 is operated at its full capacity. will be demonstrated.

26 is a water-cooled intake air cooling device (hereinafter referred to as ink cooler)
It is. The ink cooler 26 is installed in the intake pipe 4 downstream of the mechanical supercharger 7. 31 is a cooling water container through which cooling water for the ink cooler 26 is circulated. A heat exchange section 34 is disposed in the cooling water container 31, and an air conditioner cooling medium is circulated through the heat exchange section 34 as described below, thereby cooling the cooling water. The cooling water container 31 is connected to a circulation pump 36 via a cooling water passage 35, thereby forming a cooling water circulation system.

Water pump 36 is driven by a mechanical supercharger. That is, in FIG. 2, the water pump 36 is connected to the housing 3 fixed to the gear housing 7d of the mechanical supercharger 7.
6a, and a blade 36b installed on the rotor shaft 7 on the driven side of the mechanical supercharger 7. By providing the water pump 36 in the gear housing 7d as in the embodiment, the lubricating oil in the gear housing is transferred to the pump housing 36a.
The lubricating oil is cooled by the cooling water inside the lubricating oil, and the temperature of the lubricating oil can be maintained at an appropriate level, eliminating the possibility of premature thermal deterioration of the lubricating oil.

A portion 35a of the cooling water passage from the heat exchange portion 26a of the intercooler 26 can be formed within the wall surface of the intake pipe 4 as shown in FIG. is also preferable for lowering the intake air temperature. In this case, the passage portion 35a opens into the water pump 36 from the flange surface 39. In addition, the passage section 35
a can also be opened to a cooling water jacket 41 formed within the rotor housing 7b. Thereby, the supercharger itself can also be cooled. As a result, the temperature of the supercharger housing 7b is lowered, and its thermal expansion can be expected to be reduced. In this way, the clearance between the rotor 7a and the housing 7b can be further reduced, which has the effect of increasing pump efficiency. Further, by adopting a connection structure using the flange 39, the piping connection can be simplified and reliability can be improved.

In FIG. 1, the air conditioner compressor is indicated by the reference numeral 44 and is connected to the crankshaft by means of a belt 46.
It is connected to and receives its rotational driving force. The air conditioner compressor 44 is sequentially connected to a condenser 48, a receiver 50, an expansion valve 52, and an evaporator 54 via an air conditioner coolant passage 56, thereby forming a circulation system for the coolant of the air conditioner. In the figure, the flow direction of the cooling medium in the air conditioner is indicated by an arrow.

The heat exchange section 34 disposed within the cooling water container 31 is disposed in parallel with the air conditioner evaporator 54.

The refrigerant passage 34 has an expansion valve 58 and a joining T-tube 60 at one end.
The air conditioner cooling medium passage 5 downstream of the receiver 50 via
6, and the other end is connected to the downstream side of the vehicle interior evaporator 54 via a T-shaped pipe 62. A first solenoid valve 64 and a second solenoid valve 66, which are on-off valves that selectively shut off the flow of the air conditioner refrigerant, connect the passage 56 that constitutes the vehicle interior circulation system and the intercooler refrigerant circulation system, respectively. It is installed in the constituting passage 57.

In FIG. 1, a control circuit 70 controls various operations of a supercharger, an air conditioner, an oil cooling system of the present invention, and an internal combustion engine, and can be configured as a microcomputer system. That is, the control circuit 70 includes a central processing unit (CPU) 70a, a memory 70b, and an input port 0.
C, output port door 0d, and bus 70 connecting these
It is composed of e. Various sensors are connected to the input capo 1-70c in order to execute the control of the present invention, and respective detection signals are inputted thereto. An intake air amount signal Q is input from the air flow meter 6. A signal TH corresponding to the opening degree of the throttle valve 5 is input from the throttle sensor 74 . As the throttle sensor 74, for example, a sensor equipped with a rotating brush that moves together with the well-known throttle valve shaft can be adopted. This type of throttle sensor 74 is a digital type that can obtain a pulse signal depending on the opening degree of the throttle valve. Reference numeral 76 denotes an air conditioner operating switch, which is normally installed in the driver's seat and is operated when cooling the vehicle interior.

A temperature sensor 77 is installed in the cooling water container 77 in order to know the temperature T of the cooling water for the intercooler 26 (see FIG. 5).
. Further, a rotation speed sensor 79 is provided to detect the engine rotation speed Ne. This sensor can be configured, for example, as a pulse generator that generates a crankshaft rotation pulse signal.

The output port door 0d is connected to the clutch actuating part of the clutch-equipped pulley 10, the clutch part of the compressor 44, the first solenoid valve 64, and the second solenoid valve 66. And memory 7
These controls are executed according to the program stored in 0b. Of these, the operation of the supercharger 7 and the operation of the air conditioner compressor 44 by turning on and off the air conditioner switch 76 operated by the driver are not directly related to the present invention, and therefore will not be described in detail. The operation of the control circuit directly related to the present invention will be explained below with reference to the flowcharts of FIGS. 3 and 4.

FIG. 3 shows the supercharger operating routine. Ste, Pu8
At 0, the intake air amount per revolution speed ratio as a load equivalent value Q /
N e and engine rotational speed Ne are input. In step 81, it is determined whether the supercharger is operating or not based on the intake air amount-to-rotation speed ratio and the rotation speed. The supercharger 7 has an intake air amount to rotation speed ratio Q/Ne≧0.6 (1/rev) or a rotation speed Ne≧300 Orpm. In step 82, it is determined whether or not the supercharger is in the operating range. If it is in the operating range, an engagement signal for the pulley 10 to the clutch for operating the supercharger is issued in step 83, and if it is in the non-operating range, the process proceeds to step 84. A release signal for the same clutch is issued.

FIG. 4 shows the cooling control routine. In step 85, it is determined whether the air conditioner switch 76 is on. When the air conditioner switch 76 is OFF, the process proceeds to step 86 and the solenoid valve 64 is closed. Therefore, the air AINI refrigerant is prohibited from flowing through the air conditioner refrigerant circulation system 56. Step 87
Then, the temperature T of the cooling water in the cooling water container 31 is a predetermined value 'r+
(For example, it is determined whether the temperature is 30° C. or higher. If T≧T1, the process proceeds to step 88, and the operating clutch (not shown) of the compressor 44 is engaged. In step 89, the second solenoid valve 66 is opened. Therefore, the compressor 44
A cooling medium circulation system is constituted by the condenser 48, the receiver 50, the expansion valve 58, and the heat exchange section 34 of the intercooler. Therefore, the intercooler cooling water in the cooling water tank 31 is cooled. Since the water pump 36 is driven in the high load and high rotation range where the supercharger 7 operates, the cooling water in the cooling water container 31 is transferred to the intercooler 2.
The intake air is circulated to the heat exchange section 26a of No. 6, and the intake air is cooled. Further, since cooling water is not circulated in the low load and low rotation range where the supercharger 7 does not operate, sufficient cooling is performed as needed, and there is no wasteful heat radiation, so efficiency can be increased.

In step 92, it is determined whether or not there is sudden acceleration. This determination can be made, for example, by detecting the interval between pulse signals from the throttle sensor 74, and when this time interval is less than a predetermined value, it can be determined that sudden acceleration is occurring.

If it is determined that there is a sudden acceleration, the process proceeds to step 93 and the operation of the air conditioner compressor 44 is stopped. As a result, the load of the compressor 44 is no longer applied to the engine, so the load on the engine is reduced by the load of the air conditioner, and acceleration performance can be improved.

If it is not a sudden acceleration, the flow proceeds from step 92 to step 96, where it is determined whether a predetermined period of time, for example 5 seconds, has elapsed since the sudden acceleration. If it is determined that 5 seconds have passed, proceed to step 9,
An engagement signal is sent to the clutch of the air conditioner compressor 44, and the compressor 44 is driven again.

When the water temperature is less than the predetermined value T1, the process proceeds from step 87 to step 100, where it is determined whether the water temperature T has become equal to or less than the predetermined value T2 (<TI). See Figure 10. Ti<T<T
If I, proceed from step 100 to step 92,
'The same operation as when F≧T1 occurs. That is, a part of the cooling medium of the air conditioner is circulated through the cooling water container 31, and when the second solenoid valve 66 is opened, the cooling water of the intercooler 30 is transferred to the refrigerant of the heat exchange section 34a of the refrigerant passage 34 within the cooling water container 31. cooled by Also, compressor 44 during sudden acceleration
will also be stopped.

When the water temperature becomes equal to or lower than T2, the process proceeds from step 100 to step 102, and the air conditioner compressor 44 is stopped. In step 104, the second solenoid valve 66 is closed. That is, T≦
At T2, the introduction of the air conditioner cooling medium into the refrigerant passage 34 is stopped, and at the same time, the circulation of the cooling water in the cooling water container 31 is stopped.

When the water temperature exceeds T2 but does not recover to T1, the process proceeds from step 100 to step 92, so the air conditioner compressor 44 is stopped, the second electromagnetic valve 66 remains closed, and the refrigerant is circulated to the heat exchange section 34. will not be carried out. As a result, the air conditioner compressor 44 and the second solenoid valve 58 operate in a hysteretic manner as the temperature decreases and increases.

See Figure 5.

When the water temperature exceeds T again, steps 87.88°89.
92, the air conditioner compressor 44 is activated and the second
The solenoid valve 66 is opened. This continues until TST2, at which time the process proceeds to steps 100 and 102.
The air conditioner compressor 44 is stopped and the first solenoid valve 66 is closed.

When the air conditioner is in operation, the switch 76 is ON, and the process proceeds from step 85 to step 10B, where the first solenoid valve 64 is opened. Therefore, the cooling medium from the compressor 44 can go to the evaporator 54 for cooling the passenger compartment. The processing from step 110 onwards for controlling the operation of the intercooler is almost the same as the operation when the air conditioner is stopped. However, when the water temperature is lower than T2, the process proceeds from step 112 to step 104, bypassing step 102, so that the air conditioner compressor 44 is maintained in an operating state.

〔effect〕

According to this invention, a cooling water container is provided, and the intake air passage and the refrigerant passage are installed to be able to exchange heat with the cooling water in the container. The cooling water is circulated by a water pump that is driven together with a mechanical supercharger. Therefore, the cooling water cooled by the refrigerant can efficiently cool the intake air for the operation of the supercharger only when cooling is necessary.

Note that the supercharger can be driven all the time without using a clutch, but in this case, by connecting the supercharger and the water pump as in this invention, the load of the pump is always applied to the gear 7e, so the back up is reduced. Rush is eliminated and gear noise can be prevented.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment. Figure 2 shows an example of the connection piping between a mechanical supercharger and an intercooler. 3 and 4 are flowcharts illustrating the operation of the control circuit of FIG. 1. FIG. 5 is a diagram showing the operating characteristics of the solenoid valve with respect to the cooling water temperature. 4... Intake pipe 7... Mechanical supercharger 10... Pulley with clutch 18... Bypass passage 20... Bypass control valve 26... Intercooler 31... Cooling water container 36...・Water pump 44...Air conditioner compressor 64.66...Solenoid valve 70...Control circuit 76...Air conditioner switch

Claims (1)

[Claims] In an internal combustion engine for vehicles equipped with an air conditioner, which has a mechanical supercharger installed in the intake pipe and a water-cooled intake air cooling device located downstream of the supercharger, it is equipped with an independent cooling water container and A cooling medium passage branched from the intake pipe and the air conditioner is installed to be able to exchange heat with the cooling water container, and the cooling water in the cooling water container cooled by the air conditioner cooling medium cools the intake air. An intake air cooling system for an internal combustion engine, characterized in that water circulation is performed by a pump driven together with the rotation of a mechanical supercharger.