JPS6368789A - Internal combustion engine with positive displacement type supercharger - Google Patents

Abstract

PURPOSE:To intend to improve fuel consuption ratio of an engine by rotating respective rotors for discharging the intake air in a pump chamber to discharge side nearly at the time when the connection between the pump chamber and the intake side is cut off as well as discharging the intake air in the pump chamber to the intake side when the pump chamber becomes to the prescribed volumetric state. CONSTITUTION:The intake air in a pump chamber 10 is discharged into a fixed intake hollow column (8b) via the vane fitting part 6, the release port 25 and the control port21 of a rotor 1 located on the fixed intake hollow column (8b) side, during the period from the maximum volumetric state of the pump chamber 10 which is enclosed by vanes 4 of respective rotors 1, 2 to the prescribed volumetric state (the volumetric state of the pump chamber 10 at the time when the communication between the vane fitting part 6, which forms the pump chamber 10, and a control port 21 is cut off). Again, the communication between the vane fitting part 6 and discharge control port 17 is begun near the time when the communication between the vane fitting part 6 and the control port 21 is cut off, namely near the time when the communication between the pump chamber 10 and the intake side is cut off. Further, the intake side pressure on a positive displacement type supercharger is made to be higher than the discharge side pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine with a positive displacement supercharger, and more particularly to an internal combustion engine with a positive displacement supercharger that improves the fuel efficiency of the engine by controlling the capacity of the positive displacement supercharger.

In order to understand the present invention, the positive displacement supercharger will first be explained.

In the first time, the rotors 1 and 2 each have a reference cylindrical surface 3,
The blade 4 has a depressed portion from the reference cylindrical surface 3.
It has a blade fitting part 6 that communicates with the blade outer circumferential part 5, and a blade 4 that protrudes from the reference cylindrical surface 3 while being adjacent to the blade fitting part 6, and is in a state of non-contact with each other (0.1 to 0
．． They are rotated synchronously in opposite directions by a synchronizing gear (not shown) while maintaining a minute interval of about 2 mm.

The rotor 1 rotates closely around a fixed hollow body 8, and the reference cylindrical surfaces 3 of each rotor are closely spaced (
The structure is such that a minute interval of about 0.1 to 0.2 mm is maintained.

■C1 of rotor 1 (actually it is a surface, but we are thinking of a cross section) is created by the tip of ■C4 of rotor 2 (take it as a point or a small roundness), and ■C2 of rotor 1 and ■C of rotor 2 Among C6, one of ■ is the other ■
Further, if we pay attention to ■C3 of rotor 1 and ■C5 of rotor 2, one of the two ■ is created by the other ■.

Also, the tip of ■C1 of rotor 1 and ■C4 of rotor 2
A sufficient gap of about 2 to 3 mm should be left between them to allow fluid to freely enter and exit even when they are at their closest.

7 is a rotor support body that firmly fixes and supports the rotor 1.

Next, to explain the operation of this positive displacement supercharger (completely closing the bypass valves 15, 8' and closing the bypass passage 14 bypass port 9'), the pump chamber sandwiched between the blades of each rotor. 10, the supply air fully sucked into the pump chamber 10 is hermetically compressed by the reduction in the volume of the pump chamber 10, and when the pressure becomes almost equal to the pressure inside the fixed hollow body 8, the rotor 1 The liquid is discharged into the fixed hollow body 8 through the blade fitting portion 6 and the discharge port 9 formed in the fixed hollow body 8.

The P-V diagram (pressure-volume diagram) of the same pump chamber 10 is shown as the second
As shown in the figure, it has an extremely high total adiabatic efficiency.

Now, in an internal combustion engine equipped with a positive displacement supercharger as described above, in order to reduce the driving force of the supercharger in the low load range of the engine,
As shown in the figure, it has been conventional practice to fully open the bypass valves 15 and 8' to open the bypass passage 14 and the bypass port 9' to prevent deterioration in engine combustion.

However, with this method, the charge air compression work loss is almost 0.
However, mechanical friction loss when operating the supercharger still remains, and the fuel efficiency of the engine is forced to deteriorate.

Also, when the load on the engine increases and the engine is supercharged,
Bypass valve 8' is expanded (bypass port 9' is closed), but if the engine is under supercharging but not at full load, bypass valve 15 is left in a half-open position to allow compressed feed from bypass passage 14. Although it is necessary to restrict the amount of charge air supplied to the engine by releasing air (this has the effect of reducing the charge air compression work loss of the supercharger), even with this method, the amount of charge air that has passed through the bypass valve 15 A work loss corresponding to the amount of air is caused, which worsens the fuel efficiency of the engine.Furthermore, since the high-temperature charge air that has passed through the bypass valve 15 is compressed again by the supercharger, the temperature of the charge air supplied to the engine decreases. A problem arises in which the value increases.

All of these drawbacks are due to the fact that the capacity of the supercharger is not controlled.

The present invention aims to eliminate such drawbacks by controlling the capacity of the supercharger, and will be described below with reference to the drawings.

FIG. 3 shows an embodiment of the internal combustion engine with a positive displacement supercharger according to the present invention, and a side view of the positive displacement supercharger according to the present invention is shown in FIG. The diagram is shown in FIG. 4, and the sectional view taken along the line AA'■ in FIG. 5 is the same as that shown in FIG. 3.

The present invention will be explained below with reference to FIGS. 3, 4, and 5.

The fixed hollow body 8 is connected to the suction side (suction path 1
It is divided into a suction fixed + hollow body 8b leading to the inside of the discharge side (inside the discharge side passage 12) and a discharge fixed hollow body 8a leading to the discharge side (inside the discharge side passage 12).
A rotary body 20 and a discharge rotary body 16 are rotatably provided in close contact with or in contact with the inner peripheral surfaces of the fixed suction hollow body 8b and the fixed discharge hollow body 8a, respectively.

The relief port 25 formed in the fixed suction hollow body 8b is provided with a close contact piece 23 having a close contact surface 22 located on the same cylindrical surface as the periphery of the fixed suction hollow body 8b. is integrally fixed.

Furthermore, the discharge port 9 formed in the discharge fixed hollow body 80 has a
A discharge seal 19 having a discharge seal surface 18 located on the same cylindrical surface as the periphery of the discharge fixed hollow body 80 is provided, and this discharge seal piece 19 is integrally fixed to the discharge rotating body 16.

The discharge rotary body 16 is linked to the rotary body 20 via a link/cam device, gears, etc., and is rotated to a control position corresponding to the rotation position of the rotary body 20.

The rotating body 20 is linked to an accelerator pedal (not shown).

The positive displacement supercharger configured as described above is connected to the output shaft of the engine E via a belt, chain, etc.

Now, considering the low load range including the idling state of the engine E (in this case, a diesel engine), the rotary body 20 that is linked to the accelerator pedal rotates to the illustrated position and connects the relief port 25 and the rotary body 20. The discharge rotating body 16, which is aligned with the formed control port 21 and interlocks with the rotating body 20, is also rotated to the illustrated position.

Moreover, the on-off valve 29 provided in the communication passage 27 that opens at a predetermined position on the inner wall surface of the casing (rotor casing in this case) is fully open.

Therefore, if we pay attention to the pump chamber 10 sandwiched between the blades 4 of each rotor, the supply air fully drawn into the pump chamber 10 will change from the maximum volume state of the pump chamber 10 to the specified volume state (the pump chamber 10). Blade fitting part 6 forming 10
and the volume state of the pump chamber 10 at the time when the communication with the control port 21 is cut off).
is discharged into the suction fixed hollow body 8b through the suction fixed hollow body 8b, and then the communication port 24 formed in the rotating body 20 and the suction fixed hollow body 8b.
The inlet/exit opening 26 and the blade fitting part 6 and ■3 formed in
0 and further via the communication passage 27 to the suction side (into the suction passage 11) without being compressed.

In this case, the communication passage 27 is not particularly essential, but by providing it, the escape port 27 can be opened as shown in FIG.
By making the axial length of the discharge port 9 small, the axial length of the discharge port 9 can be increased, and the cross-sectional area of the discharge port 9 can be increased.

If the opening 28 of the communication path 27 is formed in the position shown in FIG. 6, the rotating body 20 does not need to be in a position where the relief port 25 is fully opened.

In short, in the low load range, including when the engine is idling,
The air supply in the pump chamber 10 is discharged to the suction side from the maximum volume state of the pump chamber 10 to the specified volume state.

Next, near (usually just before) the point in time when the communication between the vane fitting part 6 forming the pump chamber 10 and the control port 21 is cut off, that is, the point in time when the communication between the pump chamber 10 and the suction side is cut off. When approaching the vicinity, the vane fitting part 6 forming the pump chamber 10 and the discharge control port 1 formed in the discharge rotating body 16 can be seen.
7 is started, and the air supply in the pump chamber 10 is supplied to the discharge fixed hollow body 8a through the rotor blade fitting part 6, the discharge port 9, and the discharge control port 17 on the side of the discharge fixed hollow body 8a.
It is discharged into the interior and supplied to the engine E via the discharge side passage 12.

At this time, the effective discharge volume of the supercharger per revolution of the output shaft of the engine (based on the volume of the pump chamber 10 at the time when the communication between the blade fitting part 6 of the rotor 1 and the control port 21 is cut off) Since the rotational position of the rotating body 20 is determined so that the suction volume of the engine per revolution of the output shaft of the engine is larger than (generally atmospheric pressure) is the pressure on the discharge side (discharge side passage 12
(internal pressure, negative pressure).

The PV ■ diagram of the same pump chamber 10 is shown in Figure 10, and as is clear from the figure, the positive displacement supercharger generates work, that is, power corresponding to the part marked ■■. is communicated to the institution.

In general, if the supply air supplied to the engine is restricted until the pressure in the discharge side passage 12 becomes negative pressure, the fuel efficiency should deteriorate due to an increase in engine pump loss.
Because the internal pressure is negative, the engine's working chamber (suction, compression,
■Friction loss is reduced due to the reduction in the compression pressure within the space for tensioning and discharging.Furthermore, since the pressure in the discharge side passage 12 is negative pressure, the compression end temperature is maintained sufficiently due to the reduction in heat capacity in the engine's working chamber. As the fuel temperature increases, complete combustion of the fuel becomes possible, and misfires in extremely low load ranges are reduced.
Due to these synergistic effects, engine combustion does not actually deteriorate.

Now, in the present invention, power is generated in the positive displacement feeder in a low load range including when the engine is idling.

Therefore, the fuel efficiency of the engine will be improved by this amount.

Next, when the fuel injection amount increases and more air is required to be supplied to the engine, the rotating body 20 that is linked to the accelerator pedal rotates (clockwise in the figure) and the discharge rotating body 16 rotates (clockwise in the figure). is also rotated (clockwise in the figure), and the pressures on the suction side and the discharge side of the positive displacement aperture machine finally become equal.

At this time, the P-V diagram of the pump chamber 10 becomes as shown in FIG. 9, and the supply air compression work loss is zero.

When a larger amount of supply air is required to be supplied to the engine from this state, the rotating body 20 is further rotated, and the amount of supply air released into the suction fixed hollow body 8b in the pump chamber 10 is also further increased. Although the supply air in the pump chamber 10 decreases further, the volume of the pump chamber 10 decreases after the communication between the vane fitting part 6 forming the pump chamber 10 and the control port 21 is cut off. The discharge side (discharge fixed hollow body 8
When the pressure becomes almost equal to the pressure inside the pump chamber 10 (inside the inside of the pump chamber 10 or inside the discharge side passage 12), the pump enters the fixed hollow body 8a through the vane fitting part 6, the discharge port 9, and the discharge control port 17 that form the same pump chamber 10. (that is, the discharge rotating body 16 is rotated to such a position).
.

The P-V diagram of the pump chamber 10 at this time is as shown in FIG.

When the maximum amount of air supply to the engine is required, the rotary body 20 is rotated to the position where the relief port 25 is fully opened, and the discharge rotary body 16 is rotated between the discharge port 9 and the discharge control port 17. are rotated to a matching position.

The P-V diagram of the pump chamber 10 at this time is as shown in FIG.

As can be understood from the above, in the present invention, the rotating body 2
0 to control the capacity of the positive displacement supercharger, and by rotating the discharge rotating body 16, the total adiabatic efficiency of the positive displacement supercharger is maximized (inside the pump chamber 10). It controls the supply air to the engine so that there is no overcompression or undercompression.

Therefore, there is no need to control the supply air supplied to the engine by keeping the bypass valve 15 (Fig. 1) in a half-open state and wastefully releasing the supply air compressed by the supercharger to the suction side, as in the past. , the charge air compression work loss of the supercharger is significantly reduced, and the fuel efficiency of the engine is improved.

The objective of the invention is thus achieved.

The rotating body 20 is moved to the control position where the communication between the pump chamber 10 and the control port 21 is cut off at the time when the communication between the pump chamber 10 and the communication passage 27 (opening 28) is cut off. When rotated, the on-off valve 29 is closed.

In addition, when the rotating body 20 fully opens the relief port 25, the relief port is designed so that the volume of the pump chamber 10 at the time when the communication between the blade fitting portion 6 of the rotor 1 and the control port 21 is cut off is further reduced. 25 in the rotational direction of the rotor 1, and rotates the rotary body 20 so as to fully open this relief port 25 in a low load range including the idling state of the engine (the discharge rotary body 16 also rotates accordingly). The exhaust gas discharged from the working chamber of the engine (rotated to the left from the position shown in Fig. 3) is introduced into the downstream side of the positive displacement feeder (inside the discharge side passage 12, which is still under negative pressure). If configured in this manner, NO2, which is a harmful component in exhaust gas, can be reduced.

In addition, recirculating exhaust gas in a low load range, including when the engine is idling, has the effect of improving fuel efficiency, albeit slightly.

In FIG. 4, the close contact piece 23 is separated from the rotating body 20,
FIG. 7 shows an embodiment in which the close contact piece 23 is fixed at a predetermined position in the suction fixing hollow body 8b. (However, in Fig. 7, three close contact pieces 23 are provided.) With this, the escape port 2
5 will be divided into multiple parts (divided into four in the figure).

By rotating the rotating body 20, the timing of disconnecting the communication between the blade fitting part 6 and the control port 21 is changed continuously in FIG. 4, but it is changed in stages in FIG. .

The above also applies to the discharge contact piece 19 shown in FIG.

Fig. 11 shows a diesel engine with a pneumatic governor in which the present invention is implemented, and the engine is driven by a drive device 34 that is operated by the negative pressure generated in a small venturi 33 provided in an intake passage 11 connected to a positive displacement supercharger. Moving object 20
It is designed to drive.

32 is a throttle valve linked to the accelerator pedal, and since the negative pressure generated by the small venturi 33 is introduced into the pneumatic governor, the drive device 34■ moves the rotating body 20 to a control position according to the fuel injection amount. It will force you to rotate.

Other methods for rotating the rotating body 20 include a method using a stepping motor controlled by a computer.

That is, when information such as the opening degree of the accelerator pedal and the rotational speed of the engine are input into the computer as electrical signals, the computer outputs calculation results corresponding to these input values.
The output signal from this computer operates the stepping motor to rotate the rotating body 20 to the optimal control position.

In FIG. 12, the auxiliary intake valve 37 is opened for a predetermined period of time from the vicinity of the closing timing of the intake valve 36 (for example, bottom dead center ■30°) (for example, opened from bottom dead center to bottom dead center ■70°). ), a diesel engine that performs supercharging by pressurizing the supply air from the positive displacement supercharger S into the engine's working chamber in addition to the supply air that is naturally drawn into the engine's operating chamber from the air supply passage 38. The present invention is implemented in this embodiment, and the closing valve 39 is configured to be fully open and the communication valve 40 to be fully open in a low load range including the idling state of the engine.

Since the supply air is added to the intake air naturally taken in from the air supply passage 38, the positive displacement supercharger S becomes small.

This positive displacement supercharger S can be considered as a miniaturized version of the positive displacement supercharger shown in Figs. As explained above, it will be understood that power is generated in the positive displacement supercharger S in the low load range including the idling state of the engine.

It is preferable to fully open the closing valve 39 and fully open the communication valve 40 when the pressure in the discharge side passage 12 becomes approximately equal to the pressure in the suction passage 11 (usually atmospheric pressure).

By rotating the rotary body 20 and the discharge rotary body 16, the capacity of the displacement type feeder is controlled to be optimal, and the total adiabatic efficiency of the displacement type supercharger is controlled to be the highest. (There is no undercompression or overcompression in the pump chamber 10), and the fuel efficiency of the engine can be greatly improved.

The objective of the invention is thus achieved.

Next, in FIGS. 3, 4, and 5, the object of the present invention can be achieved in the same manner when the engine E is an Otto engine.

However, in the case of an Otto engine, when the engine is idling, the supply air supplied to the engine must be further reduced than in a diesel engine, so the communication between the blade fitting part 6 of the rotor 1 and the control port 21 is In order to reduce the volume of the pump chamber 10 at the moment of shutoff, the relief port 25 must be enlarged in the direction of rotation of the rotor 1.

Therefore, considering the idling state of the engine in FIGS. 3, 4, and 5, the rotating body 20 has rotated to the position where the relief port 25 is fully opened, and the supply air fully sucked into the pump chamber 10 is pumped into the pump chamber 10. The point at which the pump chamber 10 is discharged from its maximum volume state to a specified volume state to the suction side and the communication between the pump chamber 10 and the suction side is cut off (at the point where the blade fitting part 6 and the control port 21 forming the pump chamber 10 When reaching the vicinity of the point in time when the communication with the pump chamber 10 is cut off, communication between the vane fitting part 6 forming the pump chamber 10 and the discharge control port 17 is started, and the supply air in the pump chamber 10 is fixed at the discharge. It is discharged into the hollow body 80 and supplied to the engine E.

The P-V ■ diagram of the same pump chamber 10 is shown in FIG. 13, and as is clear from the figure, the positive displacement supercharger generates work corresponding to the part ■■, that is, effectiveness, and the engine's fuel efficiency. We are improving this.

If more air is required to be supplied to the engine, the rotating body 20 is rotated (clockwise in the figure).

In this way, by rotating the rotary body 20 and the discharge rotary body 16, the capacity of the positive displacement supercharger is controlled and the total adiabatic efficiency of the positive displacement supercharger is controlled to be the highest (the pump There is no undercompression or overcompression within the chamber 10), and the fuel efficiency of the engine can be significantly improved, thus achieving the object of the present invention.

Incidentally, when the engine is in a idling state and more air is required to be supplied to the engine, the rotary body 20 is rotated to increase the output, but as shown in FIG. The valve 41 may be opened.

(In a low load range, including when the engine is idling, the rotating body 20 is kept at the same control position).

When the engine is idling, the throttle valve 41 is fully closed, and when the engine is being supercharged, the closing valve 42 is fully closed.

43 indicates a fuel injection valve.

FIG. 15 shows that, as explained in FIG. 12, the air supplied under pressure from the positive displacement supercharger S is used to operate the engine, in addition to the air that is naturally introduced into the working chamber of the engine from the air supply passage 38. The present invention is applied to an internal combustion engine (in this case, an Otto engine) that is pressurized into a room for supercharging, and is configured so that when the engine is running idle, the closing valve 39 is fully closed and the communication valve 40 is fully open. There is.

Referring to the explanation in FIG. 12, it will be understood that the positive displacement supercharger S is in effect.

If more air is required to be supplied to the engine due to the idling state of the engine, the rotating body 20 may be rotated to increase the engine output, or the closing valve 39 may be opened to increase the engine output. The output may be increased.

When supercharging the engine, the closing valve 39 is fully opened and the communication valve 40 is fully closed.

The objective of the invention is thus achieved.

Incidentally, when the engine E is a rotary piston engine (Otto engine), the intake valve 36 and the exhaust valve 35 are generally unnecessary, but it is preferable to use a rotary valve as the sub-intake valve 37.

Since the present invention is configured as described above, the fuel efficiency of the engine is significantly improved.

[Brief explanation of drawings]

Figure 1 shows a conventional internal combustion engine with a positive displacement supercharger;
・Figures 8, 9, and 10 are 9-V ■ figures, 3rd, 12th, 14th, and 1st.
Figures 5 and 11 are diagrams of an internal combustion engine with a displacement type supercharger according to the present invention, Figures 4, 5, and 6 are diagrams of a displacement type turbocharger according to the present invention, and Figure 7 is a diagram of a rotating body and a suction fixed hollow. Diagram of the body, No. 13
The figure is a P-V diagram. 1 and 2 are rotors, 6 is the blade fitting part, 4 is the blade, 3
is the reference cylindrical surface, 5 is the blade outer circumference, 7 is the rotor support,
8 is a fixed hollow body, 8Q is a discharge fixed hollow body, 8b is a suction fixed hollow body, 9 is a discharge port, 10 is a pump chamber, 11 is a suction passage, 12 is a discharge side passage, 13 is an exhaust passage, 14 is a bypass passage, 15.8' is a bypass valve, 16 is a discharge rotating body, 1
7 is a discharge control port, 18 is a discharge close contact surface, 19 is a discharge close valve, 20 is a rotating body, 21 is a control port, 22 is a close contact surface, 23 is a close valve, 24 is a communication port, 25 is a relief port, 26 is a passage,
27 is a communication passage, 28 is an opening, 29 is an on-off valve, 30 is a groove, 31 is a separation wall, 32 and 41 are throttle valves, 33 is a small venturi, 34 is a drive device, 35 is an exhaust valve, and 36 is an intake valve ,3
7 is an auxiliary intake valve, 38 is an air supply passage, 39 is a closing valve, 40 is a communication valve, 42 is a loop valve, 43 is a fuel injection valve, E is an internal combustion engine, and S is a positive displacement supercharger.

Claims (2)

[Claims] (1) Each rotor has a reference cylindrical surface, a blade fitting part that has a depressed portion from the reference cylindrical surface and communicates with the blade outer circumference of the blade, and a blade fitting part that is adjacent to the blade fitting part and has the reference cylindrical surface. The rotors, each configured to have blades protruding from the cylindrical surface, synchronously rotate in opposite directions without contacting each other, and the rotor on the fixed hollow body side closely surrounds the fixed hollow body. The two rotors are configured such that the reference cylindrical surfaces of each rotor are in close contact with each other, and further include a suction fixed hollow body that communicates with the fixed hollow body to the suction side and a discharge fixed hollow body that communicates with the discharge side through a separating wall. and a rotary body and a discharge rotary body are respectively rotatably provided in close contact with or in contact with the inner peripheral surfaces of the fixed suction hollow body and the fixed discharge hollow body, and around the fixed suction hollow body. A close contact piece having a close contact surface located on the same cylindrical surface is provided in the relief port formed in the suction fixed hollow body, and a discharge close contact piece having a discharge close contact surface located on the same cylindrical surface as the periphery of the discharge fixed hollow body. A piece is provided in the discharge port formed in the discharge fixed hollow body, and by rotating the rotary body, communication between the rotor blade fitting part on the side of the suction fixed hollow body and the control port formed in the rotary body is provided. By changing the cut-off timing and rotating the discharge rotating body, the timing at which communication starts between the blade fitting portion of the rotor on the side of the discharge fixed hollow body and the discharge control port formed in the discharge rotating body is changed. In the reburning engine in which the positive displacement supercharger configured as described above is connected to the output shaft of the engine, focusing on the pump chamber sandwiched between the blades of each rotor of the positive displacement supercharger, the rotating body, By rotating the discharge rotary body to a predetermined position, the air supply in the pump chamber is discharged from the maximum volume state of the pump chamber to the specified volume state to the suction side, and communication between the pump chamber and the suction side is cut off. The structure is configured such that communication between the vane fitting portion forming the pump chamber and the discharge control port formed in the discharge rotating body is started near the point in time when the displacement type supercharger The pressure is set to be higher than the pressure on the discharge side, thereby generating power to the positive displacement supercharger, and when more air supply is required to be supplied to the engine under the above conditions, the positive displacement supercharger An internal combustion engine with a positive displacement supercharger, characterized in that supply air is further supplied to the engine via a supercharger. (2) The internal combustion engine with a positive displacement supercharger according to claim 1, wherein exhaust gas discharged from the working chamber of the diesel engine is introduced downstream of the positive displacement supercharger.