JPS6258018A - Intercooler device for engine with supercharger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present 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) In order to increase the output of an internal combustion engine, turbocharging PI! uses the energy of the exhaust gas to drive a turbine, and a compressor that is linked to the turbocharger supercharges the air taken into the engine. The first prize is known.

This type of supercharger forces a larger amount of air into the shilling 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 directly to the engine, the actual intake air filling rate will not increase much due to the decrease in air density, and the gasoline engine In this case, the problem arises that knocking becomes more likely to occur as the intake air temperature increases,
For this reason, the compression ratio was lowered and the 5α firing timing was delayed.

On the other hand, there is an intercooler that cools the intake air whose temperature has increased before it is taken into the schilling.

There are air-cooled and water-cooled intercoolers, but the air is compressed by an intake compressor, for example, from 80'C to 1
By cooling the intake air, which can reach up to 20"C, the above-mentioned problem is solved and the original function of the supercharger is fully brought out.

However, air-cooled intercoolers have a low heat exchange rate, and even water-cooled intercoolers are more difficult and complex to build than air-cooled intercoolers, but do not provide the expected cooling performance.

Therefore, in order to ensure excellent cooling performance, a boiling cooling type intercooler that efficiently cools by utilizing the large latent heat of vaporization of the refrigerant has been considered (Japanese Patent Application No. 58-2
(See Publication No. 39326) This will be explained based on FIG. 7. 1 is an engine, 2 is a supercharger consisting of an exhaust turbine 3 and an intake compressor 4;
The main body 6 of the intercooler is interposed in the middle of the air passage 5 for guiding pressurized intake air from the engine 1 to the engine 1.

This cooler main body 6 has an intake passage 5 and a number of air passages 23 for passing pressurized intake air arranged therein, and a predetermined amount of refrigerant 7 is filled inside the main body 6, which is separated from these air passages.

The refrigerant 7 is, for example, a mixture of water and antifreeze, and in this case is filled in the upper part of the cooler main body 6, leaving some space.

A steam passage 8 follows the upper part of the cooler body 6, and a condenser 9 for a refrigerant 7 is disposed on the opposite side thereof and follows it.

This condenser 9 is connected to an engine radiator (not shown).
It has a structure similar to that of the 2000, and is cooled by air from a running wind or 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 to each other via a refrigerant passage 10, and a supply pump 11 is installed in the middle thereof, thereby forming a closed loop cooling circuit.

A vacuum pump 12 is provided as means for reducing the pressure within this cooling circuit, and its suction side is connected to the steam passage 8 via a pipe 13 and a check valve 14.

This vacuum pump 12 is an electric type, and is driven and controlled by a control circuit 15 based on a signal from a vacuum sensor (pressure sensor) 16 installed in the steam passage 8. For example, as shown in FIG. 72 mmt
Reduce pressure to lg. As a result, the boiling point of the refrigerant within the cooler main body 6 is set at approximately 45°C.

Now, in this intercooler, when the high-temperature intake air pressurized by supercharging 8!2 passes through the cooler body 6, the refrigerant 7 inside the cooler body 6 is heated by the heat from the intake air, and its temperature rises. At this time, when a predetermined temperature is reached, the refrigerant 7 begins to boil and begins to evaporate while taking latent heat of vaporization from the intake air.

The refrigerant 7 boils at a predetermined low temperature depending on the pressure in the cooling circuit.
It evaporates, and its large latent heat of vaporization removes sufficient heat from the intake air.

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

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

Then, the refrigerant condensed and liquefied here is supplied to the cooler body 6 by a supply pump 11 from a refrigerant passage 10 at the bottom of the condenser 9.
It is circulated to. This supply pump 11 is constantly driven by a control circuit 15 to keep the amount of cold vL in the cooler main body 6 at a predetermined level at all times.

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

In addition, 17 is an F70-meter, 18 is a throttle valve, 19 is a fuel injection valve, 20 is an exhaust passage, and 21 is a bypass passage 22 of the exhaust turbine 3 when the supercharging pressure by the supercharger 2 becomes excessive. This is an exhaust bypass valve that allows some of the exhaust gas to escape.

(Problems to be Solved by the Invention) By the way, in this intercooler, when the pressure in the latent circuit leaks and rises, the vacuum pump 12 is driven to reduce the pressure in the circuit, and at the same time, the intruding air is removed. However, in this case, since the suction side of the vacuum pump 12 follows the steam passage 8, the steam in the circuit is likely to be sucked out, making it difficult to effectively exhaust the intruding air.

Also, the vacuum pump 12 is driven based on the signal from the vacuum sensor 16 at 6, but when there is a lot of steam in the circuit, a large amount of steam is sucked out, but the pressure in the circuit does not come down easily. First, the vacuum pump 12 will be driven for a correspondingly longer time.

Therefore, there is a problem in that the cooling performance is degraded due to the intruding air, and the amount of refrigerant in the circuit may gradually decrease.

Furthermore, a vacuum sensor 1 that detects considerably low pressure
6 has become a necessity, and therefore, it is expensive and an increase in cost cannot be avoided.

(Means for Solving the Problems) As shown in Figure t51, the present invention includes a cooler body consisting of an evaporator filled with a predetermined amount of refrigerant in the intake passage a downstream of the supercharger, This cooler body and refrigerant condenser C
A quiet loop cooling circuit is formed by communicating the upper refrigerant vapor through the vapor passage d and the lower refrigerant passage r, which returns the condensed liquefied refrigerant via the supply pump e. In an intercooler device for a supercharged engine having a vacuum pump for reducing pressure, the vacuum pump g is connected to the upper tank of the condenser C via a valve means 11, while
Means i for detecting the intake air temperature at the inlet of the cooler body and means j for detecting the refrigerant temperature within the cooler body are provided, and when either of these temperatures is lower than a set value when the engine is started, the supply pump e is driven in the reverse direction, and the vacuum pump and valve means 11 are driven so that the ! in the cooling circuit!
It is equipped with a control means k for discharging 2 air.

(Function) When the engine is started, when the intake air temperature at the inlet of the cooler body and the refrigerant temperature are low, the amount of steam in the cooling circuit is extremely small.
By driving h, the pressure in the cooling circuit is accurately reduced.

In addition, in this case, if the supply pump e is reversed to empty the refrigerant in the cooler body, the amount of vapor will not increase, and furthermore, the vacuum pump g can be moved to the condenser C, which is far from the cooler body and has a low temperature. Since it follows the upper tank, only the air is reliably exhausted without sucking out the steam in the cooling circuit as the vacuum pump g is driven.

(Embodiment) FIG. 2 is a cross-sectional view showing a configuration of an embodiment of the present invention, in which 6 is a cooler body installed in the intake passage 5 downstream of the supercharger 2, and 8 is a cooler body that supplies refrigerant vapor from the cooler body 6. 9 is a condenser that stratifies the refrigerant vapor by blowing air from a cooling fan, and 10 is a refrigerant path that returns the liquefied refrigerant 7 to the cooler main body 6 by a supply pump 11. Forms a cooling circuit.

Reference numeral 12 denotes a vacuum pump as a means for reducing the pressure within this cooling circuit, and the suction side of the vacuum pump 12 is connected to the upper tank 26 of the condenser 9 via a pipe 24 and a solenoid valve 25 as a valve means.

On the other hand, an intake air temperature sensor 27 is installed in the intake passage 5 on the upstream side of the cooler body 6 as a means for detecting the temperature of the inlet intake air flowing into the cooler body 6; Temperature sensors 28 are respectively installed, and these detection numbers 43 are sent to a control circuit 29 as a control means.

Furthermore, as means for detecting whether or not the engine 1 has been started, for example, an ignition signal from the distributor 30, a rotation speed signal from the crank sensor, etc. are sent to the control circuit 29.

Based on these signals, when the engine 1 is started, the control circuit 29 determines whether the inlet air temperature and refrigerant temperature of the cooler body 6 are higher or lower than a set value (for example, 50°C), and sets both of them. When the value is higher than the value, refrigerant passage 1
The supply pump 11 of No. 0 is driven in the normal rotation direction.

That is, the refrigerant on the condenser 9 side is force-fed to the cooler main body 6, the amount of refrigerant in the cooler main body 6 is maintained at a predetermined level, and normal operation is started.

On the other hand, when the engine 1 is started, if either the artificial intake air temperature or the refrigerant temperature of the cooler main body 6 is lower than the set value, the control line 29 switches between the supply pump 11 and the supply pump 11 based on the timing chart shown in FIG. The vacuum pump 12 and the solenoid valve 25 are driven and controlled.

Physically, even if the inlet intake air temperature and refrigerant temperature are low, when the supercharger 2 starts working when the engine starts, these temperatures gradually rise, but this rise causes these temperatures to reach the reference value ( The supply pump 11 is first driven in the reverse direction, and the vacuum pump 1 is then driven in the reverse direction.
2 to open the solenoid valve 25. After this, when the predetermined period of time has elapsed, the solenoid valve 25 is turned off and the supply pump 11 is stopped.
Further, the vacuum pump 12 is stopped, and the supply pump 1
1 in the forward rotation direction to shift to normal operation.

Note that the same reference numerals are given to the same parts as in FIG. 7 regarding other configurations.

Next, the operation will be explained based on chart 70 in FIG.

When the engine is stopped, a predetermined amount of refrigerant is maintained inside the cooler body 6, and the inside of the condenser 9 and steam passage 8 are evaporation spaces with low pressure due to the number of cooling operations.

When the engine is started in this state, it is determined in S2 whether the engine has started completely from the ignition signal, etc.
When the engine is completely started, the artificial intake air temperature and refrigerant temperature of the cooler main body 6 are compared with set values based on the signals from the temperature sensors 27 and 28 in S3.

And if both of these temperatures are higher than the set value,
Proceeding from S3 to 84, the supply pump 11 is driven in the normal rotation direction.

That is, when restarting the engine immediately after operation, the liquefied refrigerant on the condenser 9 side is sent under pressure to the cooler body 6 by the supply pump 11, thereby cooling the pressurized intake air from the supercharger 2. begins cooling operation.

Furthermore, during cooling operation, if the intake air temperature falls below the lower limit value,
That is, when there is no need to cool the intake air in a low-speed, low-load state, the process proceeds from S4 to S5 and S6, and the supply pump 11 is stopped to reduce the driving power.

On the other hand, if either the inlet intake air temperature or the refrigerant temperature is lower than the set value immediately after starting the engine,
Proceeds from S3 to S7 and S8, and at this time, as the supercharger 2 starts operating due to engine startup, these temperatures gradually rise, but when these temperatures reach the reference value, S7 and S8 start.
At 9, the supply pump 11 is driven in the reverse direction. Then, one second later, the vacuum pump 12 starts to be driven in S10, and! After 811 seconds, the solenoid valve 25 is opened.

Even if the pressure in the cooling circuit is set once, it will gradually leak and rise after a certain amount of time, allowing air to enter the circuit. of air is reliably exhausted.

That is, when the engine is started when the artificial intake air temperature and refrigerant temperature of the cooler main body 6 are low, the amount of steam in the cooling circuit is extremely small, and therefore the vacuum pump 12 is driven at this time and the solenoid valve 25 is opened. This makes it possible to accurately reduce the pressure within the cooling circuit.

In addition, in this case, the supply pump 11 is reversed and the cooler main body 6 is
Since the refrigerant inside is emptied, the amount of steam does not increase even if the intake air temperature rises, and furthermore, the vacuum pump 12 is connected to the upper tank 26 of the condenser 9, which has a low temperature and is located away from the cooler main body 6. This prevents the vapor in the cooling circuit from being sucked out by driving the vacuum pump 12, and only the air in the circuit can be reliably exhausted.

Then, one second after Sll is closed, the solenoid valve 25 is closed at 812, and S13. The supply pump 11 and the vacuum pump 12 are stopped in S14, and thereafter the normal cooling sequence of the flow in S4 starts.

However, in the diagram j@4, k is the time required to move the liquid phase refrigerant in the cooler main body 6 one direction toward the condenser 9 by the reverse drive of the supply pump 11, and l is the time required for the vacuum pump 12 to move the air in the piping 24. m is the time required for the vacuum pump 12 to remove the air from the cooling circuit and reduce the pressure to a predetermined pressure.

Therefore, the amount of refrigerant in the cooling circuit is prevented from decreasing, and constant cooling performance can be ensured.

By the way, in this embodiment, the vacuum pump 12 and the like are driven when the inlet intake temperature of the cooler body 6 and the refrigerant temperature reach a reference value (for example, 50° C.). In this manner, the pressure in the cooling circuit can always be accurately reduced by the driving time of the vacuum pump 12 without providing a vacuum sensor. Therefore, an expensive vacuum sensor is not required, and costs can be reduced.

In addition, Figures 5 and 6 show the difference in cooling performance improvement between the present device (D in the figure) and various methods (A-C in the figure). vacuum pump 12
, B is a model in which a vacuum pump 12 is followed on the condenser 9 side, and C is a model in which the refrigerant in the cooler body 6 is transferred to the condenser 9 and a vacuum pump 12 is followed in the cooler body 6 side, and the vacuum As with this device, the driving conditions for the pump 12 are such that it is driven for a predetermined time when the inlet air temperature and refrigerant temperature of the cooler main body 6 reach 50°C when the engine is started, and the pump Q enters cooling operation. QS indicates the intake air cooling heat amount under a constant operating condition, and QS indicates the intake air cooling heat amount when the vacuum pump 12 is driven at room temperature and then enters a constant cooling operation.

Therefore, according to this experiment, even if the vacuum pump 12 is driven in A-C, the air in the circuit is not properly exhausted, so the steam temperature becomes high and good cooling performance cannot be obtained. In contrast, it has been confirmed that the cooling performance of this device is significantly improved.

In addition, according to this device, since the vacuum pump 12 is driven when the engine is started when the artificial intake air temperature and the refrigerant temperature are low, there is no need to reduce the pressure in the cooling circuit in advance.

(Effects of the Invention) As described above, according to the present invention, the vacuum pump is connected to the upper tank of the condenser via the valve means, and at the time of engine startup when the inlet intake air temperature or refrigerant temperature of the cooler body is low. Since the vacuum pump is driven with the refrigerant in the cooling circuit emptied, only the air can be reliably discharged without sucking out the refrigerant in the cooling circuit, which has the effect of ensuring excellent cooling performance.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the present invention, Fig. t52 is a sectional view of the configuration showing an embodiment of the present invention, Figs. An explanatory diagram showing an air venting method and a graph showing the difference in cooling performance, and FIGS. 7 and 8 are a cross-sectional view of the configuration of a conventional example and a graph showing an example of pressure setting. 2...Supercharger, 5...Intake passage, 6...Cooler body, 8...Steam passage, 9...Condenser, 10...Refrigerant passage, 11...Supply pump, 12... Vacuum pump, 25... Solenoid valve, 26... Upper tank, 27...
・Intake air temperature sensor, 28... Refrigerant temperature sensor, 29・
...Control circuit. Figure 6: Temperature: 4, 6c, temperature: 0C

Claims (1)

[Claims] 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 having a vacuum pump that communicates condensed liquefied refrigerant with a refrigerant passage that returns via a supply pump to form a closed-loop cooling circuit and reduces the pressure in this cooling circuit, The vacuum pump is connected to the upper tank of the condenser through valve means, while means for detecting the inlet air temperature of the cooler body and means for detecting the refrigerant temperature within the cooler body are provided, and when either of these temperatures is detected, The cooling system is characterized by comprising control means for driving the supply pump in the reverse direction and driving the vacuum pump and valve means to exhaust air in the cooling circuit when the engine starts when the temperature is lower than a set value. Intercooler device for supercharged engines.