JPH0352982Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to an intercooler device that cools pressurized intake air of a supercharged engine using latent heat of vaporization of a liquid.

(Prior Art) As a means of increasing the output of an internal combustion engine, there are known turbochargers, which use energy from exhaust gas to drive a turbine, and use a compressor that works with the turbine to supercharge the air taken into the engine. ing.

This type of supercharger forces a larger amount of air into the cylinder than a naturally aspirated engine, so it is possible to increase the amount of fuel by that amount, making it possible to increase maximum output without increasing the size of the engine. be.

However, when the intake air is compressed by this supercharger, the intake air temperature rises, and if this is supplied to the engine as is, the actual intake air filling efficiency will not increase much due to the decrease in air density. A problem with gasoline engines has been that knotting is more likely to occur as the intake air temperature increases.

Therefore, there is an intercooler that cools the intake air whose temperature has increased before it is sucked into the cylinder. The present applicant has proposed an intercooler that utilizes boiling evaporation of a refrigerant (Japanese Patent Application No. 1982-239326).

To explain this based on FIG. 2, 1 is the engine, 2 is the exhaust turbine 3 and the intake compressor 4.
A main body 6 of an intercooler is interposed in the middle of an intake passage 5 that guides pressurized intake air from an intake compressor 4 to an engine 1.

This cooler main body 6 has a large number of pipe-shaped or multilayer tubular air passages 7 arranged inside thereof that are connected to the intake passage 5 and pass pressurized intake air, and a predetermined amount of refrigerant is filled inside the main body 6 fused with these air passages. be done.

The refrigerant is, for example, a mixture of water and antifreeze, and in this case is filled in the cooler body 6 with some space left in the upper part.

A steam passage 8 is connected to the upper part of the cooler main body 6,
A refrigerant condenser 9 is arranged and connected to the opposite side.

This condenser 9 has a structure substantially similar to a radiator (not shown) of an engine, and is cooled by running air or air blown from a cooling fan (not shown).

Further, the lower part of the condenser 9 and the lower part of the cooler main body 6 are connected via a refrigerant passage 10, and a supply pump 11 is installed in the middle thereof, thereby forming a closed loop cooling circuit.

Then, the pressure within this cooling circuit is reduced in advance to a predetermined pressure using a vacuum pump or the like. When water is used as a refrigerant, its boiling point is approximately 10°C under atmospheric pressure.
In order to lower this, for example, the pressure in the circuit is reduced to about 70 mmHg, and the boiling point of the refrigerant is about 45℃.
is set to

Now, in this intercooler, when the high temperature intake air pressurized by the supercharger 2 passes through the cooler body 6,
The heat from the intake air heats the refrigerant in the cooler main body 6 and its temperature rises, but when it reaches a predetermined temperature at this time, the refrigerant begins to boil and begins to evaporate while taking latent heat of vaporization from the intake air.

The refrigerant boils and evaporates at a predetermined low temperature depending on the pressure within the cooling circuit, and its large latent heat of vaporization sufficiently removes heat from the intake air.

Then, this refrigerant vapor flows from the upper part of the cooler body 6 through the steam passage 8 into the condenser 9, where it is cooled by dissipating heat by blowing air from a cooling fan or the like.
It is condensed back to the original liquid.

The heat dissipation efficiency of this steam in the condenser 9 is extremely good, so even relatively weak ventilation can sufficiently promote cooling and condensation of the steam.

The refrigerant condensed and liquefied here is circulated from the refrigerant passage 10 at the bottom of the condenser 9 to the cooler main body 6 by the supply pump 11. This supply pump 11 is constantly driven, and an overflow passage (not shown) formed in the cooler body 6 always maintains the amount of refrigerant in the cooler body 6 at a predetermined level.

In this way, the high-temperature intake air from the supercharger 2 is efficiently cooled, and therefore the intake air temperature can be accurately lowered even with a small amount of refrigerant, and excellent cooling performance can be obtained.

In addition, 12 is an air flow meter, 13 is a throttle valve, 1
4 is a fuel injection valve, 15 is an exhaust passage, and 16 is an exhaust bypass valve that opens the bypass passage 17 of the exhaust turbine 3 to release part of the exhaust gas when the boost pressure from the supercharger 2 becomes excessive. .

(Problem to be Solved by the Invention) However, in such an intercooler, the supply pump 11 that pumps the refrigerant liquefied in the condenser 9 to the cooler body 6 is connected to the refrigerant passage 10 with a small diameter.
Since the refrigerant is installed in the middle of the refrigerant, the performance of the pump 11 may be adversely affected by the suction pressure of the pump 11 generated when pumping the liquefied refrigerant.

In devices that utilize such a phase change of liquid, the liquid refrigerant and vapor in the cooling circuit are always in a state close to saturation, and therefore, the suction pressure caused by the drive of the supply pump 11 increases the suction. When the pressure on the suction side decreases, the high-temperature refrigerant immediately after liquefaction causes reduced pressure boiling due to the decrease in pressure, and tends to cause so-called cavitation on the suction side.
The flow rate of the pump 11 may be reduced, or in severe cases, the pump 11 may be stopped.

(Means for Solving the Problems) According to this invention, in the intercooler device as described above, the rotor portion of the supply pump is directly disposed within the lower tank of the condenser.

(Function) Therefore, since the suction side of the supply pump opens directly into the lower tank of the condenser, the suction port of the supply pump expands, the suction loss is reduced, and the suction pressure becomes sufficiently small.

(Example) Figure 1 is a sectional view of the main part showing an example of the present invention.
9 represents a condenser that condenses and liquefies refrigerant vapor from the cooler body (see FIG. 2).

The refrigerant condensed and liquefied in the condenser 9 is stored in a lower tank 9a with a predetermined volume attached to the lower part of the condenser 9.
The refrigerant is temporarily stored in the lower tank 9 and is circulated from there to the cooler body via the refrigerant passage 10.
A concave portion 18 that projects downward is formed at one bottom portion of a. One side 19 of this recess 18 is formed into a curved shape so as to smoothly connect with the bottom surface 20 thereof.

A refrigerant passage 1 is provided on the side surface 19 of this recess 18.
0 is open-connected, and the rotor portion 22 of the supply pump 21 is disposed within the recess 18 .

The rotor section 22 of the supply pump 21 is composed of a flexible rotor in which a large number of vanes 24 made of an elastic body (such as rubber) are protruded radially from the outer periphery of a boss section 23, and a motor section (not shown) that rotationally drives the rotor 22. ) is installed on the side of the lower tank 9a.

The vane 24 of this flexible rotor 22 is
The tip contacts the bottom surface 20 and side surface 19 of the recess 18, and a pressure chamber 25 whose volume is reduced in accordance with the rotation of the rotor 22 is formed between the vane 24, the bottom surface 20, and the side surface 19. .

Note that both ends of the vane 24 are formed so as to be in sliding contact with the lateral surface 26 of the recess 18, and these surfaces 19, 2
0 and 26 form the housing of the supply pump 21. The other configurations are the same as in FIG. 2.

With this configuration, the refrigerant condensed and liquefied in the condenser 9 falls into and is stored in the lower tank 9a, and is then pressure-fed from there through the refrigerant passage 10 to the cooler main body by driving the supply pump 21. The suction pressure caused by driving the supply pump 21 is extremely small.

That is, since the rotor portion 22 of the supply pump 21 is disposed directly within the lower tank 9a, the supply pump 21
The suction port is enlarged, reducing suction resistance. Furthermore, since the rotor section 22 rotates within the lower tank 9a, the refrigerant between the vanes 24 smoothly enters the pressure chamber 25 as the rotor section 22 rotates, and when it comes to the opening of the refrigerant passage 10, the refrigerant flows out. Pressure chamber 2
Refrigerant passage 1 at a predetermined discharge pressure due to the volume change of 5.
Pushed to 0. As a result, the supply pump 21
The suction pressure becomes sufficiently small.

Therefore, the pressure on the suction side of the supply pump 21 does not decrease, and cavitation due to the decrease in pressure can be prevented from occurring, and as a result, the supply pump 21 can always maintain good operation. becomes possible.

In addition, since the recess 18 is formed in the lower tank 9a, even when the amount of refrigerant in the lower tank 9a is small, the refrigerant can be reliably sent from the recess 18 to the cooler main body.

(Effects of the invention) As described above, according to the invention, since the rotor of the supply pump is directly disposed within the lower tank of the condenser, cavitation caused by the suction pressure of the supply pump can be prevented, and the supply Good operation of the pump can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional example. 2...Supercharger, 5...Intake passage, 6...Cooler body, 8...Steam passage, 9...Condenser, 9a...
lower tank, 10... refrigerant passage, 18... recess,
21... Supply pump, 22... Rotor section.

Claims (1)

[Scope of utility model registration request] A cooler body consisting of an evaporator filled with a predetermined amount of refrigerant is interposed in the intake passage downstream of the supercharger, and the cooler body and the refrigerant condenser are connected to a vapor passage leading to refrigerant vapor in the upper part and a vapor passage in the lower part. In an intercooler device for a supercharged engine that forms a closed-loop cooling circuit in which condensed liquefied refrigerant is returned via a supply pump and a refrigerant passage is formed, the rotor portion of the supply pump is directly connected to the lower tank of the condenser. An intercooler device for an engine equipped with a supercharger.