JPH05202820A - Intake device for engine - Google Patents

Abstract

PURPOSE:To prevent one of an intercooler and an intake-air heating means which is not used, from affecting the other of them which is used, by connecting, in parallel, an intake passage for the intake-air heating means to an intake passage for the intercooler so that it branches from the intake-air passage for the intercooler. CONSTITUTION:An intercooler 19 is disposed in an intake passage 10 downstream of a supercharger 16, and is connected thereto with a bypass passage 13 bypassing the intercooler 19 so that the bypass passage 13 branches from the intake passage 10. An intake-air heating means 25 is connected in the bypass passage 13, in parallel with the intercooler 19. Further, a heating means side shut-of valve 39 is disposed in the bypass passage 13 downstream of the intake- air heating means. Further, an intercooler side shut-off valve 37 is disposed in the intake-air passage 10 upstream of the intercooler 19 but downstream of the upstream end branching part of the bypass passage 13. With this arrangement, in, for example, a condition in which heating is made by the heating means 25, the shutoff valve 39 retrains intake-air discharged from a supercharger 16 from flowing into the intercooler under dynamic pressure, thereby the intake- air may effectively flow into the bypass passage 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for an engine, and more particularly to an intake system provided with heating means for heating intake air in addition to an intercooler for cooling intake air pressurized by a supercharger.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 2-11962.
As shown in Japanese Patent Publication No. 3, etc., a supercharger for supercharging intake air is provided in the intake passage of the engine, and an intercooler is provided in the intake passage downstream of the supercharger, and the intercooler raises the temperature in the supercharger. It is well known to cool the intake air to increase the charging efficiency of the intake air.

On the other hand, as disclosed in Japanese Utility Model Laid-Open No. 54-58512, for example, intake air heating for heating intake air in the intake passage in order to improve ignition performance and combustion stability in a low engine speed low load region. Providing means is also known.

[0004]

By the way, utilizing these conventional ideas, an intercooler and an intake heating means are arranged in parallel in the intake passage on the downstream side of the supercharger, and an on-off valve is provided in each intake passage. In order to heat the intake air, the intake air is heated through the intake air heating means, and then the intake air is supplied to the engine while it is cooled. At times, if the air is supplied via the intercooler, the temperature of the intake air can be varied within a wide range according to the operating state of the engine.

In this case, in the state where the intake air from the supercharger is cooled by the intercooler, a high output is required of the engine. It is conceivable that the intake passage is connected smoothly to the upstream and downstream sides, the bypass passage is branched and connected to the intake passage, and the intake heating means is arranged in the bypass passage.

However, since only one of the intercooler and the heating means is used, the temperature of the intake air cooled by the intercooler or heated by the heating means depends on the position of each on-off valve due to the inertia of the flow of the intake air. Becomes unstable under the influence of the non-use side device of the other side of the intercooler or the heating means. For example, when the on-off valve on the heating means side is arranged in the bypass passage on the upstream side of the heating means, the downstream side of the bypass passage is always open to the intake passage on the intercooler side. In the state where the side opening / closing valve is opened and the intake air is cooled by the intercooler, the intake air in the bypass passage on the downstream side of the heating means and heated by the heating means is easily sucked by the intake air flowing through the intercooler to the engine. As a result, the temperature of the intake air supplied to the engine cannot be lowered efficiently.

When the intercooler-side open / close valve is arranged in the intake passage on the downstream side of the intercooler, the intercooler is always opened to the upstream supercharger, so the open / close valve on the heating means side is opened and the intercooler-side open / close operation is performed. Even when the valve is closed and the intake air is heated by the heating means, part of it flows into the intercooler due to the dynamic pressure of the intake air discharged from the supercharger, is cooled by the intercooler, and then flows into the bypass passage. As a result, a loss occurs in the rise in intake air temperature.

The present invention has been made in view of these points, and an object thereof is a structure in which the intake passage of the intake heating means is branched and connected in parallel as a bypass passage to the intake passage of the intercooler as described above. By properly setting the position of the on-off valve disposed in each intake passage, it is possible to prevent the non-use side influence due to the inertia of the intake flow when using either the intercooler or the intake heating means.

[0009]

In order to achieve the above object, in the invention of claim 1, the on-off valve on the intercooler side is
The upstream side of the intercooler is arranged in the intake passage downstream of the branch portion at the upstream end of the bypass passage, and the heating means side opening / closing valve is arranged in the bypass passage downstream of the heating means.

That is, according to the present invention, in the engine provided with the supercharger for supercharging the intake air and the intercooler arranged in the intake passage on the downstream side of the supercharger for cooling the intake air,
A bypass passage branched and connected between the intake passages on the upstream and downstream sides of the intercooler, an intake heating means arranged in the bypass passage in parallel with the intercooler for heating intake air, and a bypass passage on the downstream side of the intake heating means. A heating means-side opening / closing valve arranged in the bypass passage and an intercooler-side opening / closing valve arranged in the intake passage upstream of the intercooler and downstream of the upstream end branch portion of the bypass passage are provided. ..

According to the second aspect of the present invention, the injector for supplying and injecting the fuel to the intake system takes in the assist air supplied for atomizing the injected fuel from the upstream side of the intercooler and the heating means. ..

That is, according to the present invention, in the engine intake system according to claim 1, an assist air passage for supplying assist air toward the fuel discharge portion of the injector for fuel injection supply is provided, and the assist air passage is provided. The upstream end is connected to the intake passage upstream of the intercooler and the intake heating means.

According to the third aspect of the invention, the assist air is taken from the bypass passage on the downstream side of the heating means only during cold time.

That is, according to the present invention, in the engine intake system according to the second aspect, the upstream end of the assist air passage is an intake passage upstream of the intercooler and the intake heating means, the intake heating means and the heating means side opening / closing. It is connected to both the bypass passage between the valve and the valve, and is configured to supply the assist air to the injector from the bypass passage between the intake air heating means and the heating means side opening / closing valve when cold. Is characterized by.

[0015]

With the above construction, in the invention of claim 1, since the opening / closing valve on the heating means side is arranged in the bypass passage on the downstream side of the intake heating means, the opening / closing valve on the heating means side is closed and the opening / closing valve on the intercooler side is closed. In a state where the intake air is cooled by the intercooler, the intake air in the bypass passage on the downstream side of the heating means and heated by the heating means is closed by the intake air flowing to the engine through the intercooler. It can be blocked by the heating means side opening / closing valve, and the temperature of the intake air supplied to the engine can be lowered without loss.

Further, since the intercooler-side opening / closing valve is arranged in the intake passage upstream of the intercooler and downstream of the upstream end branch portion of the bypass passage, the heating means-side opening / closing valve is opened and the intercooler-side opening / closing valve is opened. In a state where the intake air is closed and heated by the heating means, it is possible to effectively prevent the intake air discharged from the supercharger from flowing into the intercooler due to the dynamic pressure by the on-off valve and to effectively flow into the bypass passage. Therefore, the effect of raising the intake air temperature by the heating means can be secured. In this way, when one of the intercooler and the intake air heating means is used, it is possible to prevent the influence on the non-use side due to the inertia of the flow of intake air.

According to the second aspect of the invention, since the upstream end of the assist air passage for supplying air toward the fuel discharge portion of the injector is connected to the intercooler and the intake passage upstream of the intake heating means, the intercooler and Assist air that is not affected by the temperature of the heating means can be obtained, and the assist air temperature can be stabilized.

Further, according to the invention of claim 3, only in the cold state,
Since the assist air is supplied from the bypass passage between the intake heating means and the heating means side opening / closing valve, the assist air can be heated by effectively utilizing the heating means for heating the intake air. Atomization of fuel can be achieved.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall configuration of an embodiment of the present invention, where 1 is 2
This is a rotor type rotary engine. This engine 1 has two rotor housings 2 and 2 each having a trochoidal surface on the inner circumference, and three side surfaces that are hermetically assembled between the rotor housings 2 and 2 and on both sides of each rotor housing. Housing 3,
3, and each of the spaces surrounded by the housings 2 and 3 has three working chambers 4, which serve as combustion chambers.
.. (only one of which is shown) are partitioned to form rotors 5, respectively. The rotors 5 are supported by an output shaft 6 so as to be eccentrically rotatable. The eccentric rotation of the rotor 5 causes the working chamber 4 to sequentially perform suction, compression and exhaust strokes to rotate the output shaft 6. I'm trying to drive. A cooling fan 7 is attached to the front end of the output shaft 6.

The central side housing 3 is provided with primary ports 8 and 8 as intake ports communicating with the working chamber 4 in the intake stroke of each of the above spaces, and the side housings 3 and 3 on both sides are also similar. Secondary port 9
Are opened respectively. Each of these ports 8 and 9
Intake passage 10 for supplying intake air to the working chamber 4 in the intake stroke
Constitutes the downstream end of the. That is, the intake passage 1
0 is a primary passage 11 in which the downstream side portion is branched into two and the downstream end of each branching portion is defined as each primary port 8 in the central side housing 3, and similarly, the downstream side portion is branched into two. The secondary end of each branch portion is provided with the secondary passage 12 which is the secondary port 9 in each of the side housings 3 on both sides, and the collecting portions of the primary passage 11 and the secondary passage 12 are at the upstream end. They are assembled together. An upstream end of the intake passage 11 is connected to an air cleaner 14, and an air flow meter 15 for detecting an intake air amount (intake amount) and an intake air are supercharged in the intake passage 11 on the downstream side of the air cleaner 14. A compressor 17 that constitutes one half of the turbocharger 16, an air-cooled intercooler 19 that cools the intake air pressurized by the compressor 17 by exchanging heat with the running wind of an automobile, and a throttle valve 20 that throttles the intake passage 10. Are sequentially arranged from the upstream side, and the intake passage 10 is branched into a primary passage 11 and a secondary passage 12 on the downstream side of the throttle valve 20.

On the other hand, each rotor housing 2 of the engine 1
An exhaust port 21 is formed in the exhaust port 21, and the exhaust port 21 constitutes an upstream end portion of an exhaust passage 22 for exhausting exhaust gas from the working chamber 4 in the exhaust stroke. In the exhaust passage 22, a turbine 18 that constitutes the other half of the supercharger 16 and
An exhaust emission control device 23 and a silencer 24 are arranged in order from the upstream side.

The supercharger 16 is provided upstream of the intercooler 19
The intake passage 10 downstream of the compressor 17 and the intake passage 10 downstream of the intercooler 19 and upstream of the throttle valve 20 constitute a part of the intake passage.
It is branched and connected by 3. At that time, the air discharged from the compressor 17 of the supercharger 16 is supplied to the intercooler 1
In the state of cooling by 9, the engine 1 is required to have a high output, so that the intake passage 10 in which the intercooler 19 is arranged is located upstream and downstream of the intake passage 10 as shown in FIG. And smoothly,
The bypass passage 13 is branched and connected so as to be bent substantially at a right angle to the intake passage 10.

An interheater 25, which constitutes an intake air heating means for heating intake air (air), is arranged in the bypass passage 13 in parallel with the intercooler 19. The interheater 25 includes a water jacket (not shown) and cooling water pipes 26 and 27 in the engine 1.
The cooling water is circulated through the cooling water, and the interheater 25 heats the intake air by exchanging heat with the cooling water of the engine 1. In FIG. 1, a radiator 28 is connected to a water jacket of the engine 1 by cooling water pipes 29 and 30 so as to be able to circulate cooling water, and a water pump 31 is disposed in the middle of the return passage side cooling water pipe 29. .. The cooling water pipe 29 on the upstream side of the water pump 31 and the cooling water pipe 30 on the outward path are short-circuited by a bypass pipe 32, and a thermostat 33 for switching a flow path is provided at a connecting portion between the bypass pipe 32 and the outgoing side cooling water pipe 30. Are arranged.

As shown in FIG. 2, the intercooler 19 is located at the front end of the engine room 34 in the front part of the vehicle body in front of the radiator 28 and at the interheater 25.
Are arranged above the engine 1 at a position higher than the intercooler 19 by a predetermined height. 2 in FIG.
5 is a front wheel.

Returning to FIG. 1 again, the intercooler 19 is
An intercooler-side open / close valve 37, which is a butterfly valve driven by an actuator 36 to open / close the intake passage 10, is provided in the intake passage 10 on the upstream side of the bypass passage 13 and on the downstream side of the upstream end branch portion of the bypass passage 13. 25
An interheater-side on-off valve 39, which is a butterfly valve that is driven by an actuator 38 to open and close the bypass passage 13, is disposed in the bypass passage 13 on the downstream side. The both actuators 36, 38 are configured to be operated and controlled by an engine control unit 51, and the control unit 51 receives an output signal of the air flow meter 15 and a signal of an intake negative pressure (boost) on the downstream side of the throttle valve 20. , Various signals including an engine speed signal are input, and the control unit 51 controls the opening / closing valves 37 and 39 to open / close to selectively cool the intake air by the intercooler 19 or heat the interheater 25. I'm trying to choose. Specifically, as shown in FIG. 4, when the engine 1 is in the low speed range and the low load range where the intake negative pressure is low, the interheater side opening / closing valve 39 is opened and the intercooler side opening / closing valve 37 is closed. While the intake air is passed through the bypass passage 13 to be heated by the interheater 25 and the heated air is supplied to the engine 1, the engine 1 is in the high rotation range or in the high load range where the intake negative pressure is high. Occasionally, the intercooler side opening / closing valve 37 is opened and the interheater side opening / closing valve 3 is opened.
By closing 9
The engine 1 is cooled by the intercooler 19 by passing 0.
I am trying to supply it to.

Further, injectors 40 as fuel supply means for injecting and supplying fuel are arranged in the primary passages 11 near the respective primary ports 8, and the operation of each injector 40 is controlled by the control unit 51. As shown in the enlarged detail of FIG. 3, each injector 40 has a fuel injection direction that obliquely intersects the center line direction of the primary passage 8 and is directed downstream in a mounting hole 42 formed through the wall portion of the primary passage 8. Thus, the seal member 43 is attached. Seal member 4
A cylindrical sleeve 44 is fitted into the mounting hole 42 below 3 with a gap between it and the injector 40, and an annular space 45 is formed between the outer periphery of the sleeve 44 and the side surface of the mounting hole 42. Has been done. Further, in the sleeve 44, at the position corresponding to the fuel discharge port 41 of the injector 40 inside thereof, the annular space 45 outside the sleeve 44 and the sleeve 44 are provided.
A large number of small holes 46, 46, ... Which communicate with the inside are formed at intervals in the circumferential direction. The annular space 45 communicates with an assist air passage 47 formed in the wall of the primary passage 8. The assist air passage 47 is for supplying air toward the fuel discharge port 41 of the injector 40 to atomize the injected fuel, and as shown in FIG. 1, its upstream portion branches into two. The upstream end of one of the assist air passages 47 is located upstream of the intercooler 19 and the interheater 25.
Intake passage 10 between the compressor 17 and the compressor 17 of the supercharger 16
Further, the upstream end of the other assist air passage 47 is connected to the bypass passage 13 between the interheater 25 and the interheater side opening / closing valve 39. Further, a duty solenoid valve 48 whose operation is controlled by the control unit 51 is disposed in the assist air passage 47 connected to the bypass passage 13. By controlling the duty solenoid valve 48, the interheater can be operated during cold. 25, the assist air heated by the interheater 25 is supplied to the injector 40 from the bypass passage 13 between the open / close valve 39 and the interheater side opening / closing valve 39.

Next, the operation of the above embodiment will be described. Intercooler side and interheater side open / close valves 37, 3
9 is controlled by the control unit 51 to be opened / closed in accordance with the operating region of the engine 1, and the interheater side opening / closing valve 39 is opened and the intercooler side opening / closing valve 37 is closed when the engine 1 is required to heat intake air at a low rotation and low load. .. In this state, the discharge air from the supercharger 16 flows into the bypass passage 13 that bypasses the intercooler 19, is heated by heat exchange with the engine cooling water in the interheater 25 of the bypass passage 13, and then passes through the throttle valve 20. And then supplied to the engine 1.

At this time, the intercooler-side on-off valve 37 in the closed state is located in the intake passage 1 upstream of the intercooler 19 and downstream of the upstream end branch portion of the bypass passage 13.
Since it is arranged at 0, even if the air discharged from the supercharger 16 tries to flow into the intercooler 19 through the smoothly continuous intake passage 10 due to the dynamic pressure, the fact that the air is discharged to the intercooler side opening / closing valve The air can be effectively flowed into the bypass passage 13 by being regulated by 37. As a result, it is possible to effectively prevent a part of the air discharged from the supercharger 16 from flowing into the intercooler 19 and being cooled, and it is possible to secure the effect of increasing the intake air temperature by the interheater 25 and to improve the fuel ignitability. The combustion stability can be surely improved by increasing the combustion speed and increasing the combustion speed.

On the other hand, the intercooler side opening / closing valve 37 is opened and the interheater side opening / closing valve 39 is closed at the time of high rotation or high load of the engine 1 which is required to cool the intake air. In this state, the discharge air from the supercharger 16 does not flow into the bypass passage 13 as described above, and the intercooler 19
After flowing straight through the intake passage 10 with a certain temperature, and after being cooled by heat exchange with the running wind of the car in the intercooler 19,
It is supplied to the engine 1.

At this time, the interheater side opening / closing valve 39
Is arranged in the bypass passage 13 on the downstream side of the interheater 25, the air in the bypass passage 13 on the downstream side of the interheater 25 and heated by the interheater 25 passes through the intake passage 10 having the intercooler 19 and the engine 1 Even if the air flowing into the device is sucked, it can be prevented by the closed interheater side opening / closing valve 39. As a result, the temperature of the intake air to the engine 1 can be lowered as desired without increasing the air temperature due to the mixture of the heated air from the interheater 25, and the intake charging efficiency can be increased to increase the output of the engine 1. Can be increased. Moreover, since the intake passage 10 in which the intercooler 19 is arranged is smoothly continuous with the upstream and downstream sides thereof, the resistance of the air flowing through the intercooler 19 can be reduced and a high output of the engine 1 can be obtained.

Therefore, in this embodiment, when one of the intercooler 19 and the interheater 25 is used as described above, the influence of the inertia of the intake flow on the non-use side can be reliably prevented.

Further, as shown in FIG. 2, the engine room 3
Since the inter-heater 25 is arranged at a position higher than the inter-cooler 19 in 4, the convection due to the density difference caused by the temperature difference between the air cooled by the inter-cooler 19 and the air heated by the inter-heater 25 is less likely to occur. ,
The effect of the non-use side can be prevented more effectively.

Further, in this embodiment, during the operation of the engine 1 as described above, assist air is supplied to the fuel discharge port 41 of each injector 40 by the assist air passage 47, and the assist air is used to atomize the fuel. Is planned. Then, in a normal state other than the cold state, the duty solenoid valve 48 upstream of the assist air passage 47 is provided.
Is closed, and the upstream end of the assist air passage 47 is upstream of the intercooler 19 and the interheater 25.
Air flow meter 15 and compressor 17 of supercharger 16
Is communicated with the intake passage 10 between, and is not affected by the temperatures of the intercooler 19 and the interheater 25.
Assist air equivalent to the outside air temperature is supplied to each injector 40, and the assist air temperature can be stabilized.

On the other hand, in the cold state, the duty solenoid valve 48 is opened, and the assist air heated by the interheater 25 is supplied to the injector 40 from the bypass passage 13 between the interheater 25 and the interheater side opening / closing valve 39. (For details, see Air Flow Meter 15
Intake passage 10 between the compressor 17 and the compressor 17 of the supercharger 16
The assist air mixed with the air supplied from is supplied. Further, the temperature of the assist air can be positively controlled by controlling the opening degree of the duty solenoid valve 48). Therefore, the interheater 25 provided for heating the intake air can be effectively used to heat the assist air without requiring a dedicated heating device for heating the assist air.
The fuel can be atomized.

The present invention can also be applied to a reciprocating engine.

[0036]

As described above, according to the invention of claim 1, an intercooler is arranged in the intake passage on the downstream side of the supercharger, and a bypass passage bypassing this intercooler is branched and connected. The intake air heating means is arranged in parallel with the intercooler in the passage, and the heating means side opening / closing valve is arranged in the bypass passage on the downstream side of the intake air heating means, while it is downstream of the upstream end branch portion of the bypass passage on the upstream side of the intercooler. By installing the intercooler-side opening / closing valve in the intake passage on the side, in the state where the intake air is cooled by the intercooler, the intake air that is heated by the heating means in the bypass passage becomes the intake air that flows to the engine through the intercooler. While the suction valve is blocked from being sucked, the intake air discharged from the supercharger is blocked by the dynamic pressure in the state where it is heated by the heating means. The on-off valve can suppress the inflow of air into the intercooler, and it can effectively flow into the bypass passage.When using either the intercooler or the intake air heating means, the influence of the inertia of the intake air flow on the unused side can be reduced. It can be effectively prevented.

According to the invention of claim 2, the upstream end of the assist air passage for supplying air toward the fuel discharge portion of the injector for fuel injection supply is connected to the intake passage upstream of the intercooler and the intake heating means. Therefore, the assist air can be stabilized at a constant temperature that is not affected by the temperatures of the intercooler and the heating means.

According to the third aspect of the invention, the upstream end of the assist air passage is provided with an intake passage upstream of the intercooler and the intake heating means, and a bypass passage between the intake heating means and the heating means side opening / closing valve. Since it is connected to both of the above, and when cold, assist air is supplied to the injector from the bypass passage between the intake heating means and the heating means side opening / closing valve.
It is possible to atomize the fuel from the injector during cold while heating the assist air by effectively utilizing the heating means for heating the intake air.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a schematic side view showing a layout of intercoolers and interheaters in an automobile.

FIG. 3 is an enlarged cross-sectional view showing a structure of a fuel injection portion of the injector.

FIG. 4 is a characteristic diagram showing operating regions of an intercooler and an interheater.

[Explanation of symbols]

 1 engine 10 intake passage 13 bypass passage 16 supercharger 19 intercooler 20 throttle valve 25 interheater (intake air heating means) 37 intercooler side opening / closing valve 39 interheater side opening / closing valve (heating means side opening / closing valve) 40 injector 41 fuel discharge port 47 assist air Passage 51 Engine control unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Niitani 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Motor Corporation

Claims (3)

[Claims] 1. An engine including a supercharger for supercharging intake air and an intercooler for cooling the intake air, which is disposed in a downstream intake passage of the supercharger. A bypass passage branched to the intake passage, an intake heating means arranged in the bypass passage in parallel with the intercooler for heating intake air, and a heating means arranged in the bypass passage downstream of the intake heating means. An intake system for an engine, comprising: an opening / closing valve; and an intercooler-side opening / closing valve arranged in an intake passage upstream of an intercooler and downstream of an upstream end branch portion of a bypass passage. 2. The intake system for an engine according to claim 1, wherein an assist air passage for supplying assist air toward a fuel discharge portion of an injector for fuel injection supply is provided, and an upstream end of the assist air passage is An intake device for an engine, which is connected to an intake passage upstream of an intercooler and intake heating means. 3. The intake system for an engine according to claim 2, wherein the upstream end of the assist air passage is between the intake passage upstream of the intercooler and the intake heating means, and between the intake heating means and the heating means-side on-off valve. It is connected to both of the bypass passages and the bypass passage between the intake air heating means and the heating means side on-off valve when cold, and is configured to supply assist air to the injector. Engine intake device.