JPS5993923A - Internal-combustion engine with supercharger - Google Patents

Abstract

PURPOSE:To improve fuel consumption in the partial load area of an engine, by causing a supercharger to generate power within a partial load area including a racing condition. CONSTITUTION:When an engine is in a racing condition, throttle valves 12 and 13 are closed, and after feed air flows in an operation chamber 7 through an air feed passage 11 on the inlet side, the feed air in the operation chamber 7 is adiabatically expanded, and is exhausted in an air feed passage 16 on the outlet side. In a partial load area, the throttle valves 13 and 12 are slightly opened, and feed air flows in the operation chamber 7 through the air feed passage 10 on the inlet side and the air feed passage 9 on the outlet side. This causes a supercharger 1 to generate a work, equivalent to a part shown by slant lines, i.e., power. The power is equivalent to the work which is generated when the feed air, flowing in the operation chamber 7 until its volume reaches a point Vc, is adiabatically expanded from its status with an atmospheric pressure Po to the status with a pressure Pi (negative pressure) in the air feed passage 16 on the outlet side.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a supercharged internal combustion engine with improved fuel efficiency.

Generally, in a supercharged internal combustion engine, the fuel efficiency of the engine deteriorates due to reasons such as a reduction in the compression ratio to prevent knocking and an increase in friction loss caused by driving the supercharger.

The present invention aims to significantly improve fuel efficiency by generating power in the supercharger itself in a partial load range, including when the engine is idling, and transmitting this power to the engine. explain.

FIG. 1 shows an embodiment of a supercharged internal combustion engine according to the present invention.
The engine is equipped with a supercharger 1 connected to the engine (to the output shaft) via a chain belt or the like (a fuel injection device having a fuel injection valve 2 is used as the fuel supply device).

From the inlet side air supply passages 9, 10, 11 to the working chamber 7 (supercharger 1
Refers to the space with a change in volume at rotor 3 in the figure.
, the space formed by the vanes 4, the rotor housing 5, and the side housing 6) is pressurized and then supplied to the engine through the outlet side air supply passage 16 to perform supercharging. It's getting old.

Now, considering the idling state of the engine, the throttle valves 12 and 13 are both fully closed, and focusing on one working chamber 7, the process from the minimum volume state to the maximum volume state of the working chamber 7 is At some point (hereinafter referred to as point Vc), the communication between the notch 8 formed in the rotor 3 and the inlet air supply passage 11, that is, the communication between the notch 8 and the opening 14 of the inlet air supply passage 11 is cut off. (Since the inlet side air supply passages 10, 11, etc. are formed in the side housing 6 on the front side than in the drawing,
(indicated by a chain double-dashed line).

Therefore, at the Vc point, the communication between the working chamber 7 and the inlet air supply passage 11 is cut off, that is, the inflow of air supply from the inlet air supply passage of the supercharger 1 into the working chamber 7 is cut off. The idling state of the engine is maintained by the air supply.

In this case, it is desirable that the air supply flowing into the working chamber 7 from the inlet side air supply passage 11 is not throttled by the throttle valve, and that the pressure in the working chamber 7 at the Vc point is atmospheric pressure (of course, The Vc point may be delayed and the supply air flowing through the inlet air supply passage 11 may be throttled accordingly, but the degree of throttling of the supply air should be kept to a minimum).

After the communication between the working chamber 7 and the inlet air supply passage 11 is cut off at the Vc point, the air supply in the working chamber 7 expands adiabatically, and the air is transferred to the outlet side of the supercharger 1, i.e. Outlet side air supply passage 1
At the point when the pressure (negative pressure) in the working chamber 7 becomes almost equal to the pressure (negative pressure) in the working chamber 7, the air supply in the working chamber 7 advances one space ahead of the working chamber 7 through the opening of the inlet air supply passage 9 as shown in the figure. (direction of rotation of the rotor 3) into the working chamber 7, and this working chamber 7 on the forward side is communicated with the outlet side air supply passage 16 via the communication passage 17. Ultimately, the air is discharged into the outlet air supply passage 16.

FIG. 2 shows a PV diagram (pressure-volume diagram) of the working chamber 7 when the throttle valves 12 and 13 are fully closed.

As is clear from the figure, in the present invention, the supercharger 1 generates work corresponding to the shaded area, that is, power. In other words, the supply air that has flowed into the working chamber 7 up to the Vc point The engine obtains power corresponding to the work generated when expanding adiabatically from the atmospheric pressure Po to the pressure Pi (negative pressure) in the outlet air supply passage 16.

Next, when the throttle valve 13 is opened in order to increase the output of the engine, the inlet side air supply passage 10 has an opening 15 formed at the notch 8.
By communicating with the working chamber 7, more supply air flows into the working chamber 7, increasing the output of the engine.

When the throttle valve 13 is further opened, the throttle valve 12 begins to open, and a large amount of supply air flows into the working chamber 7 from the inlet air supply passage 9, further increasing the engine output, and finally supercharging occurs. (In this case, the throttle valves 12 and 13 are mechanically interlocked with each other and may be opened at the same time.)

Even in the partial load range of the engine where the throttle valve 13 (or 12) is slightly open, the pressure in the working chamber 7 at point Vc remains at the supercharger 1.
Since the pressure is sufficiently higher than the pressure (negative pressure) on the outlet side of the air supply passage 16, the supercharger 1 still generates power and transmits it to the engine.

As described above, according to the present invention, power is generated in the supercharger 1 in the partial load range including the idling state of the engine, and this is transmitted to the engine, so that in the partial load range of the engine Fuel efficiency is significantly improved, and overall fuel efficiency is significantly improved despite being a supercharged internal combustion engine (although fuel efficiency worsens when supercharging is performed).

The communication passage 17 is connected when the engine starts to be supercharged (
(When the pressure inside the outlet side air supply passage 16 exceeds atmospheric pressure)
It is closed by an on-off valve 18 linked to a diaphragm device 19 that senses the pressure in the outlet side air supply passage 16 and operates, thereby preventing backflow of air supply.

Figure 3 shows when the communication path 17 is removed (when it is not formed)
The P-V diagram of the working chamber 7 is shown, and the small part represented by the vertical line (this is the part where the working chambers 7 communicate with each other when the vane 4 passes through the opening of the inlet side air supply passage 9). The communication passage 17 is not indispensable, since it only slightly reduces the power generated by the supercharger 1 as negative work.

When the inlet side air supply passage 11 is also fully closed or almost completely closed when the engine is decelerated, the deceleration characteristics of the engine (that is, of the vehicle, etc.) are improved due to intake resistance loss of the supply air.

In addition, when the engine is idling, after cutting off the supply air into the working chamber 7 at the Vc point, prevent the supply air from flowing into the working chamber 7 again (that is, the supply air is cut off at the Vc point). Although it is desirable to completely cut off the inflow of the engine, the throttle valve 13 may be opened slightly to allow a minute flow of supply air to flow in, thereby finely adjusting the rotational speed when the engine is idling.

In FIG. 1, an opening 14 is formed in the side housing 6 in order to cut off the communication between the working chamber 7 and the inlet air supply passage 11 at point Vc, but if the number of vanes 4 is increased (
For example, if the number of cutouts 8 is increased to 6), this opening 14 can be formed in the rotor housing 5 as schematically shown in FIG. ).

5 and 6 schematically show other types of controlling the air supply flow rate flowing through the inlet side air supply passage 10 in Fig. 1 (these types can also be applied to the inlet side air supply passage 9). ).

First, in FIG. 5, (B) shows a cross section taken along the line A-A' in (A), and a large number of long holes 20 are oriented in the radial direction of the rotor 3 at positions corresponding to the openings of the inlet side air supply passages 10. The height b of the elongated hole 20 is set to a>b with respect to the thickness a of the vane 4.
It is configured so that.

In addition, a throttle valve 13' is provided in the side housing 6 to open and close these long holes 20.

Therefore, when the vane 4 passes through these long holes 20, the working chambers 7 do not communicate with each other via the long holes 20 (when the working chambers 7 communicate with each other, there is no flow into the working chamber 7 until the point Vc). Before the inflowing supply air is sufficiently expanded, it is sucked into the working chamber 7 on the advance side by one space, and the outlet air supply passage 16
(As a result, the power generated by the supercharger decreases.)

In order to increase the output of the engine, the throttle valve 13' may be rotated at the same time as the throttle valve 12, or slightly earlier than the throttle valve 12, so that the elongated holes 20 are sequentially opened.

Next, in FIG. 6 (FIG. 5 is further simplified and only the main parts are drawn), (B) shows a cross section taken along line B-B' of (A), and shows the opening of the inlet side air supply passage 10. 15 is closed by the throttle valve 13'', and this throttle valve 13'' is provided at a position retracted by a minute distance ■S from the inner wall of the side housing 6, so that the throttle valve 13'' and the vane 4 are connected to each other. It is designed to avoid collisions.

Therefore, when the vane 4 passes through this throttle valve 13'', it can be almost ignored that the working chambers 7 communicate with each other.

To increase the output of the engine, rotate the throttle valve 13'';
The effective cross-sectional area of the opening 15 communicating with the working chamber 7 is gradually increased.

FIG. 7 shows the communication between the working chamber 7 and the inlet air supply passage 11 by V.
The throttle valve 23 is cut off at point c, and a large number of elongated holes 20 formed at positions corresponding to the openings of the inlet side air supply passage 21 are
The output of the engine is increased by opening them sequentially.

The relationship between the thickness of the vane 4 and the height of the elongated hole 20, the configuration of the throttle valve 23, etc. are as explained in FIG. 5.

In this case, the throttle valve 23 may be opened and closed by an accelerator pedal (not shown);
may be arranged and opened and closed by a diaphragm device 24 that operates by sensing the pressure in the space between them (
At this time, the pressure in the outlet air supply passage 16 is introduced into the space between the throttle valves 23 and 22 via the pressure introduction passage 25).

When the engine is idling, the throttle valve 22 is fully closed, and therefore the throttle valve 23 is also fully closed by the diaphragm device 24.
When the throttle valve 22 linked to the accelerator pedal is opened from this state, the pressure in the space between the throttle valves 23 and 22 immediately increases (the negative pressure in the space between them immediately decreases), so the throttle valve 23 opens. It opens instantly and increases the output of the engine.

In this case, the flow rate of the air supply supplied to the engine is essentially controlled by the throttle valve 22.

When the engine is supercharged, the outlet air supply passage 1
The supply air flowing through 6 will flow back through the pressure introduction passage 25, but since the diameter of the pressure introduction passage 25 is extremely small,
The backflow amount can be ignored (if the pressure introduction passage 25 is provided with a check valve, the backflow of the supply air can be completely prevented).

Although the elongated hole 20 is formed in the side housing 6,
It is also possible to form it in the rotor housing 5.

This is shown in FIG. 11. In this case, two vanes 4' are used as a set, and the distance between each vane 4' in contact with the inner wall of the rotor housing 5 is c. For example, if the height b of the elongated hole 20 is set such that d>c>b, when the vane 4' passes through the elongated hole 20, the working chambers 7 will not communicate with each other (that is, the supercharging (The power generated by the machine will not decrease unexpectedly.)

The opening and closing of the throttle valve 23 is as explained in FIG. 7.

FIG. 8(a) shows that after the working chamber 7 communicates with the inlet air supply passage 11 through the notch 8 up to point Vc, the supply air flowing into the working chamber 7 does not expand adiabatically and immediately The air is discharged through the opening of the inlet side air supply passage 21 and the communication passage 17 to the outlet side of the supercharger 1, that is, into the outlet side air supply passage 16, and the PV line of the working chamber 7 is A diagram is shown in the same figure (b).

In the figure, turbocharger 1 has work corresponding to the shaded area.
In other words, power is generated and fuel efficiency is significantly improved in the partial load range, including when the engine is idling.

Next, in FIG. 9, (b) is drawn with the throttle valve 28 taken out to help understand (a), and the throttle valve 28 sliding in the annular groove 27 is opened and closed (rotated). It is designed to control the output of the engine.

When the engine is idling, the opening of the inlet air supply passage 26 is already partially opened by the throttle valve 28 (indicated by 27'), and this opening 27' is connected to the working chamber 7 through the notch 8. At the same time, the communication is cut off at the Vc point, so that the engine is maintained in an idling state.

If the throttle valve 28 is opened by an accelerator pedal (not shown),
The effective cross-sectional area of the opening of the inlet air supply passage 26 increases (the period of communication with the working chamber 7 becomes longer), and a large amount of supply air flows in, increasing the output of the engine.

It is needless to say that the throttle valve 28 is retracted from the inner wall of the side housing 6 by an amount .smallcircle.S as shown in FIG. 6 to avoid collision with the vane 4.

FIG. 10 shows an embodiment in which the throttle valve 28 is opened and closed by a diaphragm device.

That is, in FIG. 10, (b) is drawn with the throttle valve 28 taken out to help understand (a), and when the engine is idling, the throttle valves 28 and 29 are fully closed, but the inlet side Supply air flows into the working chamber 7 from the air supply passage 11 through the notch 8, and the inflow is blocked at the Vc point, so that the engine is maintained in an idling state.

When the throttle valve 29 is opened by the accelerator pedal (not shown), the throttle valve 28 is immediately opened by the diaphragm device 24, and a large amount of supply air flows in from the opening of the inlet side air supply passage 26, and the engine The diaphragm device 24 opens and closes the throttle valve 28 as described above with reference to FIG. 7.

Incidentally, if this type of throttle valve 28 is applied to the one shown in FIG.
0 can be formed from a position near the opening 14 of the inlet air supply passage 11.

FIG. 12 shows an example in which the present invention is implemented in an internal combustion engine equipped with a supercharger 30 having a rotor housing 32 formed of a trochoidal surface. When the engine is idling, the throttle valve 36 is fully closed and the main shaft The rotary valve 37, which is driven at a speed of 1/2 of the rotation of (closes the inlet side air supply passage 39)
, the engine is kept running idle.

Therefore, the supply air that has flowed into the working chamber 34 up to the Vc point expands adiabatically to the pressure on the outlet side of the supercharger 30 (negative pressure in the outlet side air supply passage 42), and then flows into the communication passage 41. The air is discharged to the outlet side of the supercharger 30 (into the outlet side air supply passage 42) through the supercharger 30, thus generating power in the supercharger 30 and greatly improving the fuel efficiency of the engine.

When the throttle valve 36 is opened, a large amount of supply air flows into the working chamber 34 from the inlet air supply passage 35, increasing the output of the engine.

When the engine is supercharged, the communication passage 41 is
Needless to say, it will be closed as shown in the figure.

As described above, in the present invention, power is generated in the supercharger in a partial load range including the idling state of the engine, and power is transmitted from the supercharger to the engine, so that fuel efficiency is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a supercharged internal combustion engine according to the present invention, and FIG.
・Figures 3 and 8 (b) are P-V diagrams of the working chamber, Nos. 4, 5, and 6.
・Figures 7, 8 (a), 9, 10, and 11 are schematic diagrams of the supercharger according to the present invention, and FIG. 12 is a sectional view of the turbocharger according to the present invention. 1 and 30 are superchargers, 2 is a fuel injection valve, 3 and 31 are rotors, 4 and 4' are vanes, 5 and 32 are rotor housings, 6 and 33 are side housings, 7 and 34 are working chambers, and 8
are notches, 9, 10, 11, 21, 26, 35, 39 are inlet side air supply passages, 12, 13, 13', 13'', 23,
22, 28, 36 are throttle valves, 14, 15, 27' are openings, 16, 42 are outlet air supply passages, 17, 41 are communication passages,
18 is an on-off valve, 19 and 24 are diaphragm devices, 20 is a long hole, 25 is a pressure introduction passage, 27 is an annular groove, 37 is a rotary valve, 38 is a closing portion, and 40 is a main shaft. Patent applicant Shuichi Kitamura

Claims (3)

[Claims] (1) In an internal combustion engine that controls output by changing the density of air supply supplied to the engine, a supercharger having a working chamber with a volume change is connected to the engine, and one working chamber in which the supercharger is located is connected to the engine. Focusing on this, the supply air flowing into the working chamber is cut off in the middle of the process from the minimum volume state to the maximum volume state, and the pressure inside the working chamber at this time is Make sure that the pressure is sufficiently higher than the pressure on the outlet side of the feeder,
When the output of the engine is increased from this state, the engine output is controlled by further inflowing supply air into the same working chamber, and the engine is finally supercharged. Internal combustion engine with feeder. (2) The supercharger according to claim 1, wherein the inflow of supply air into the working chamber is completely blocked in the middle of the process from the minimum volume state to the maximum state of the working chamber volume. Internal combustion engine. (3) Even after cutting off the supply air flowing into the working chamber in the middle of the process from the minimum volume state to the maximum state,
An internal combustion engine with a supercharger according to claim 1, wherein a minute flow rate of supply air is allowed to flow into the working chamber.