JPS6318133A - Supercharge device for engine - Google Patents

Abstract

PURPOSE:To improve the combustion efficiency of an engine, by providing a correcting means which corrects the set maximum supercharge pressure of the waist gate device of an exhaust turbo supercharger to a lower value in a specified running area, where an exhaust turbo supercharger is actuated simultaneously with a mechanical supercharger. CONSTITUTION:An exhaust turbo supercharger 15 with a waist gate device 18 is disposed between a suction passage 4 and an exhaust passage 6. A spot located up a line from a blower 15c of the supercharger 15 in the suction passage 4 is connected to a spot located down a line from a blower 15c and up a line from a throttle valve 7 through an auxiliary suction passage 27, and a mechanical supercharger 28, driven by an engine, is located in the middle of the passage 27. When the working time of the mechanical supercharger 28 is detected by a working time detecting means 43, an on-off valve 26 serving as a correcting means 44 is closed to stop an escape of a supercharge pressure from a passage 24, through which a supercharge pressure is guided to a diaphragm device 22 for driving a waist gate valve 21. This constitution corrects the set maximum super pressure of the waist gate device 18 to a low value.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to engine supercharging devices, and in particular, in addition to exhaust turbo superchargers, it also applies to n-mechanical superchargers driven by the engine, that is, superchargers. This invention relates to an improvement in which intake air is supercharged using two superchargers.

(Prior Art) Conventionally, as a supercharging 8M for this type of engine, for example, as disclosed in Japanese Patent Application Laid-Open No. 59-138748,
When the engine is running, the exhaust gas exhaust pressure is used to constantly operate the exhaust turbo supercharger to supercharge the intake air to the engine according to the exhaust pressure, and the mechanical supercharger is activated depending on the engine operating status. Especially when the vehicle is rapidly accelerating, the exhaust turbo supercharger has poor operational response and turbo lag occurs, so by operating the mechanical supercharger to ensure this responsiveness, the intake air is It is known that the vehicle is supercharged to improve the acceleration performance of the vehicle.

(Problems to be Solved by the Invention) By the way, in exhaust turbo supercharging, a waste gate device is usually provided that regulates the maximum supercharging pressure of intake air to a set value υJ. ￥Q fixed R at this waste gate R1fY
The high boost pressure value is set with particular consideration to ensuring good combustion efficiency of the engine. In other words, in the exhaust passage, when the turbine of the exhaust turbo supercharger is driven to rotate by the exhaust pressure of the exhaust gas, the existence of this turbine prevents the smooth discharge of the exhaust gas, increasing the exhaust pressure, and as a result, the combustion Since the amount of residual gas brought into the chamber increases and the combustion efficiency of the engine decreases, generally the maximum boost pressure value set is the boost pressure value just before the combustion efficiency of the engine decreases. This is done to ensure as much combustion efficiency as possible. For this reason, in an engine equipped with such an exhaust turbo supercharger, when the engine is operating at high speed, the combustion efficiency of the engine is controlled by the maximum boost pressure set by the waste gate device, which further improves the combustion efficiency. The disadvantage was that it was not possible to improve the

(Object of the Invention) The present invention has been made with a particular focus on the operation of the mechanical supercharger described above, in order to improve the combustion efficiency of the engine.

In other words, when the mechanical supercharger is operating, the supercharging share of the exhaust turbo supercharger is reduced due to the supercharging of the intake air, and the exhaust gas is discharged more smoothly, reducing the exhaust pressure. Since the carry-over of residual gas is reduced, the combustion efficiency of the engine is improved, and the engine output increases even when the boost pressure is the same value.In other words, by changing the boost pressure to a lower value. We focused on the fact that combustion efficiency can be improved while keeping the engine output at the same value, and the purpose is to change the maximum boost pressure setting of the wastegate device to this mechanical supercharger when the mechanical supercharger is operating. By adjusting the feeder to a lower value than when it is not operating, the engine output is maintained at the desired value, and the amount of residual gas carried in is reduced, increasing the engine combustion efficiency and increasing the engine output torque. At the same time, the objective is to improve fuel efficiency by reducing fuel consumption by the amount that increases combustion efficiency of the engine under the same engine output.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention includes an exhaust turbo supercharger having a waste gate device that regulates the maximum supercharging pressure of intake air to a set value; The present invention is based on an engine supercharging device that includes a mechanical supercharger driven by an engine and that operates the mechanical supercharger according to the operating state of the engine. Then, at the time of operation of the mechanical supercharger, which is detected by the operation detection means for detecting the operation of the mechanical supercharging type, and the operation detection means, the set maximum supercharging pressure value of the waste gate device is lowered. The configuration includes a correction means for correction.

(Function) With the above configuration, in the present invention, when the engine is operating, the exhaust turbo supercharger is constantly operated by the exhaust pressure of the exhaust gas to supercharge the intake air. In a specific operating range such as during rotation, the exhaust turbo supercharger is driven more and the intake supercharging pressure increases, and the maximum value of the supercharging pressure is regulated to the set value by the waste gate device, and this In this state, the mechanical supercharger operates, and supercharging of intake air is performed by both the exhaust turbo supercharger and the mechanical supercharger.

In that case, along with the supercharging of the intake air by mechanical supercharging, the supercharging share of the exhaust turbo supercharger is reduced, and the exhaust gas is discharged more smoothly and the residual gas is carried into the combustion chamber. As the amount decreases, the combustion efficiency of the engine improves and the engine output tends to increase. However, at this time, the maximum boost pressure setting of the wastegate device is corrected to a lower value by the correction means, and the maximum boost pressure of the intake air is regulated to this set value, so the engine output remains unchanged without increasing. While being maintained at a desired value, the output torque of the engine increases due to the improved combustion efficiency of the engine, and fuel consumption is reduced, resulting in improved fuel efficiency.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of an engine supercharging device according to the present invention, in which 1 is an engine, 2 is a combustion chamber whose volume is variable by a piston 3 of the engine 1, and 4 is connected to the atmosphere through an air cleaner 5 at one end. an intake passage that communicates with the combustion chamber 2 and whose other end opens into the combustion chamber 2 to supply intake air (air) to the engine 1;
Reference numeral 6 denotes an exhaust passage whose one end is open to the combustion arm 2 and the other end is open to the atmosphere to discharge exhaust gas, and in the middle of the intake passage 4 is a throttle valve 7 for controlling the amount of intake air; Fuel injection valves 8 for injecting fuel into the intake passage 4 on the downstream side of the throttle valve 7 are respectively arranged, and an intake valve 9 is arranged at the opening of the intake passage 4 to the combustion chamber 2. It is set up. Further, an exhaust valve 10 is disposed at the opening of the exhaust passage 6 into the combustion chamber 2.

Furthermore, an exhaust turbo supercharger 15 is disposed between the intake passage 4 and the exhaust passage 6, spanning both roads 4 and 6. The exhaust turbo supercharger 15 includes a turbine 15a rotatably disposed in the exhaust passage 6, and a blower connected to the turbine 15a via a connecting shaft 15b and disposed upstream of the throttle valve 7 in the intake passage 4. 15c, the turbine 15a rotates in response to exhaust pressure from the exhaust gas flowing through the exhaust passage 6, thereby rotationally driving the blower 15c and supercharging the intake air from the intake passage 4 to the engine 1. .

Furthermore, the exhaust turbo supercharger 15 is equipped with a waste gate device 18 that regulates the intake hen supercharging pressure to a set value. The waste gate device @18 is connected to the exhaust passage 6
a bypass passage 20 that bypasses the turbine 15a of the exhaust turbocharger 15;
The diaphragm device 22 includes a wastegate valve 21 that opens and closes the wastegate valve 21 and a diaphragm device 22 that opens and closes the wastegate valve 21.
1 through a link device M423, a pressure chamber 22b and an atmospheric chamber 22c formed by dividing the inside of the main body into two by the diaphragm 22a, and a spring 22d compressed in the atmospheric chamber 22C. , the biasing force of the spring 22d is set in advance to a supercharging pressure value that is a micro value △P and Cb lower than the regulation value PO immediately before the combustion efficiency of the engine 1 decreases due to an increase in the exhaust pressure of the exhaust passage 6. P.L.
It is set to 111 (Po - ΔP) corresponding to . Furthermore, the pressure downstream of the blower 15c in the intake passage 4, that is, the supercharging pressure of intake air, can be introduced into the pressure chamber 22b via the pressure introduction passage 24. Furthermore, the middle of the pressure passage 24 is communicated with the upstream side of the blower 15c of the intake passage 4 via a small-diameter bypass passage 25, and the bypass passage 25 has a normally open on-off valve 26 that opens and closes the bypass passage 25. is interposed, and when the supercharging pressure of intake air is introduced into the pressure chamber 22b, a part of the supercharging intake air is passed through the bypass passage 25.
By bypassing the intake passage 4 to the upstream side of the blower 15C through the intake passage 4, the supercharging pressure of the intake air is reduced by a minute pressure ΔP and introduced into the pressure 122b. Therefore, when the intake boost pressure is below the regulation value PoJX, the pressure '
! When the pressure value acting on the spring 22b becomes less than the biasing force (Po-△P) of the spring 22d, the diaphragm 22a is biased to the right in the figure by the biasing force of the spring 22d, and the wastegate valve 21 is bypassed. Passage 2
0 is closed to supply the entire amount of exhaust gas to the turbine 15a, while the supercharging pressure of the intake air exceeds the regulation value Poe, the pressure value acting on the pressure chamber 22b is increased by the biasing force of the spring 22d (
Po−△P), this pressure causes diaphragm 2
2a is now biased to the left in the figure, and the waste gate valve 21 opens the bypass passage 20, thereby allowing a part of the exhaust gas from the exhaust passage 6 to flow through the bypass passage 20, thereby causing the exhaust turbo supercharging v115 to flow. By bypassing the turbine 15a and discharging it to the exhaust passage 6 on the downstream side, a further increase in boost pressure is suppressed, and the maximum value of the intake boost pressure is regulated to the above regulation [Po]. It is configured.

In addition, an exhaust turbo supercharger 15 in the intake passage 4
The upstream side of the blower 15c and the downstream side of the blower 15C and the upstream side of the throttle valve 7 are connected to each other through a sub-intake passage 27, and in the middle of the sub-intake passage 27, there is a mechanical A supercharger 128 is provided. Further, the downstream side of the mechanical supercharging 8!28 of the sub-intake passage 27 is as follows:
The turbine 1 in the exhaust passage 6 via the secondary air supply passage 29
5a is connected to the downstream side of the secondary air supply passage 29, and at the connection part of the secondary air supply passage 29 with the sub-intake passage 27, the intake air of the sub-intake passage 27 is connected to the upstream side of the throttle valve 7 of the intake passage 4 and the secondary air supply passage 29. A three-way valve 30 is disposed to selectively supply air to the secondary air supply passage 29 side, and when the three-way valve 30 operates to communicate with the secondary air supply passage 29 side, the intake air supercharged by the mechanical supercharger 28 is transferred to the secondary air supply passage 29 side. It is supplied as air to the downstream side of the turbine 15a in the exhaust passage 6 to oxidize carbon monoxide and the like in the exhaust gas to purify the exhaust gas, while when the three-way valve 30 operates to communicate with the upstream side of the throttle valve 7 in the intake passage 4, Supercharged intake air from the auxiliary intake passage 27 is supplied to the engine 1.

Furthermore, 35 is an air flow sensor that detects the intake air amount to the engine 1 on the upstream side of the connection between the intake passage 4 and the auxiliary intake passage 27, and 36 is a secondary air flow sensor that detects the secondary air flow in the secondary air supply passage 29. 37 is a rotational speed sensor that detects the rotational speed of the engine 1; 38 is an opening sensor that detects the opening of the throttle valve 7;
Each detection signal of 8 is input to a controller 40 equipped with a CPU, etc., and the controller 40 controls the operation of the fuel injection valve 8, the on-off valve 26, and the three-way valve 30, respectively. be done.

That is, the controller 40 controls the air flow sensor 35
2 detected by the secondary air flow indicator from the intake air amount detected by
The actual amount of intake air is determined by subtracting the next air flow, and the operation of the fuel injection valve 8 is controlled so that the amount of fuel corresponds to this amount of intake air. The operating state of the engine 1 is determined based on the engine speed and throttle valve opening (that is, engine load), and when the engine operating state is in normal operation except for a specific operating range such as a high-speed, high-load range, the three-way valve 30 2
The three-way valve 30 is operated to communicate with the intake passage 4 side when the secondary air supply passage 29 side is operated to purify the exhaust gas with secondary air (supercharged air), while in the above-mentioned specific operating range, the three-way valve 30 is operated in communication with the intake passage 4 side. Then, the mechanical supercharger 28 is substantially operated to supply supercharging air from the mechanical supercharging 'a28 to the combustion chamber 2.

In addition, when it is in the above specific operating range, the three-way valve 3
Mechanical supercharger 28 due to the communication operation to the intake passage 4 side of
functions as an operation time detection means 43 for detecting the operation time of the
Upon detection of this operation, the on-off valve 26 is operated to close,
By blocking a partial bypass of the supercharged intake air via the bypass passage 25, the supercharging pressure of the intake air is regulated i! Even if it does not reach iPo, if the supercharging pressure is Po-62 or higher, the diaphragm 22a of the wastegate R1ff18 is biased against the biasing force of the spring 22d, and the wastegate valve 21 is opened. Wastegate installation @
Correction means 4 for correcting the set maximum boost pressure value of No. 18 to a set value (Po-△P) lower by a minute value △P from the regulation value Po.
4. In addition, in Figure 1, 4
6 is opened when the supercharging pressure of the intake air supercharged by the mechanical supercharger 28 reaches a set value (maximum value), and the auxiliary intake passage 2 is opened.
7 is a relief valve that relieves the supercharged intake air to the upstream side of the mechanical supercharger 128, and 47 is a spark plug disposed at the top of the combustion chamber 2.

Therefore, in the above embodiment, when the engine 1 is operating, the exhaust turbo supercharging fi 15 is constantly operated by the exhaust pressure of the exhaust gas flowing through the exhaust passage 6, and the intake air in the intake passage 4 is adjusted according to the exhaust pressure value. is supercharged, and the exhaust turbo supercharger 15 is driven more as it moves toward a specific operating range such as a high rotation and high load range, and the supercharging pressure gradually increases, and this supercharging pressure reaches the regulation value PO.
When it reaches Po, the waste gate device 18 is activated to restrict further increase, and the supercharging pressure is maintained at this restriction value Po.

When the engine operating state shifts to a specific operating range in this state, the mechanical supercharging R2B is activated, and as shown in FIG. The amount of intake air shown is supplied by the mechanical supercharger 28.

As a result, the turbine 15 of the exhaust turbocharger 15
The amount of work a, that is, the supercharging share of the exhaust turbo supercharger 15, is reduced by that amount, and the exhaust gas is discharged that much more smoothly, so that the exhaust pressure in the exhaust passage 6 is reduced by the solid line in the figure (d). When the exhaust gas decreases as shown and only the exhaust turbo supercharger 15 operates (
(indicated by the broken line). As the exhaust gas is smoothly discharged, the amount of residual gas brought into the combustion chamber 2 is reduced, and the combustion efficiency of the engine 1 is improved, and the output of the engine 1 is about to increase. 18 regulations ff1Potfi correction means 44
As a result, the intake supercharging pressure is corrected to be lower by a minute value △P, and the intake supercharging pressure decreases by that amount as shown in the same figure (a), so the engine 1
The output of the engine 1 is maintained at the same value without increasing or changing, and in this state of the same engine output, the output torque of the engine 1 increases as shown by the solid line in FIG. , is larger than when only the exhaust turbo supercharging [15 is activated, as shown by the broken line], and the amount of fuel injected from the fuel injection valve 8 is reduced by the amount that the combustion efficiency of the engine 1 increases under the same engine output. This will improve fuel efficiency. Therefore, while maintaining the engine output at a desired value, it is possible to increase torque and improve fuel efficiency by improving engine combustion efficiency due to reduction in exhaust pressure.

Further, FIG. 3 shows another embodiment, in which the supercharged air from the mechanical supercharger 28 is supplied upstream of the throttle valve 7, and the supercharged air from the exhaust turbo supercharger 15 is combined with the supercharged air from the exhaust turbo supercharger 15. Instead of merging the air and supplying it to the combustion chamber 2, the supercharged air from the mechanical supercharger 28 is independently supplied to the combustion chamber 2, and the ff1J intake passage 27- on the downstream side of the three-way valve 30 is combusted. The sub-intake valve 50 opens directly into the combustion chamber 2 and is arranged at the opening to the combustion chamber 2 so as to be able to operate synchronously with the intake valve 9. In addition, in the same figure, 51 is υj intake'i! J road 27
- A wholesale control valve disposed downstream of the three-way valve 30,
! 1 Engine 1 with intake air supercharged by mechanical supercharger 28
This is to control the supply amount to

Therefore, in this embodiment as well, as shown in FIG. 4, the supercharging share of the exhaust turbo supercharger 15 decreases as the mechanical supercharger 28 operates, and the exhaust passage 6
Since the exhaust pressure of the engine 1 is reduced, the combustion efficiency of the engine 1 is improved, output torque is increased and fuel efficiency is improved, and the ¥2 constant maximum boost pressure injection of the waste gate device 18 is corrected to a lower value. As a result, the output of the engine 1 is maintained at the same value, so that it is possible to increase the output torque and improve fuel efficiency while keeping the engine output at the desired value. In this case, since the auxiliary intake passage 27- opens into the combustion chamber 2 independently of the intake passage 4, the supercharging pressure of the exhaust turbo supercharger 15 is as shown in FIG. 4(A). Although it decreases slightly with the operation of the correction means 44, the supercharging pressure of the mechanical supercharger 28 does not decrease and remains at the same value.

(Effect of Bu Saiaki) As explained above, according to the engine supercharging device of the present invention, in a specific operating range where the exhaust turbo supercharger and the mechanical supercharger operate simultaneously, the exhaust turbo supercharger Since the set maximum boost pressure value of the waste gate device 18 was corrected to a lower value,
While ensuring the engine output at the desired value, it is possible to increase the combustion efficiency of the engine by reducing the exhaust pressure due to the reduction in supercharging share of the exhaust turbo supercharger, increasing output torque and improving fuel efficiency. .

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show an embodiment of the Mokkomei, in which FIG. 1 is an overall schematic diagram and FIG. 2 is an explanatory diagram of the operation. FIG. 3 shows another embodiment and is a general schematic diagram, and FIG. 4 is a first explanatory diagram of intercropping. 1...Engine, 4...Intake passage, 6...Exhaust passage, 15...Exhaust turbo supercharging, 18...Wastegate H! , 21... waste gate valve, 22...
Diaphragm device, 2G...on/off valve, 27.27-.
...Sub-intake passage, 28...Mechanical supercharger, 37...
Rotation speed sensor, 38...Opening degree sensor, 40...Controller, 43...Operation detection means, 44...Correction means. Patent Applicant Mazda Co., Ltd. Agent Patent Attorney Former 1) Hiro□1-', -1 Figure 2 Figure 4 Zuukanken

Claims (1)

[Claims] (1) Equipped with an exhaust turbo supercharger having a waste gate device that regulates the maximum intake pressure to a set value, and a mechanical supercharger driven by the engine, the mechanical supercharger is connected to the engine. An engine supercharging device configured to operate according to operating conditions, comprising an operating time detection means for detecting when the mechanical supercharger is operating, and a mechanical supercharger detected by the operating time detection means. A supercharging device for an engine, comprising: correction means for correcting a set maximum supercharging pressure value of the wastegate device to a lower value when the wastegate device is operated.