JP5345198B2 - Engine air supply device with EGR device and engine equipped with the same - Google Patents

Description

  The present invention is mainly applied to a diesel engine with an EGR (exhaust gas recirculation) device, and includes an EGR passage that recirculates a part of the exhaust gas of the engine into an air supply port that supplies air to each cylinder. The EGR passage relates to an air supply device for an engine with an EGR device configured to supply EGR gas extracted from an EGR extraction portion of one cylinder to an EGR introduction portion of another cylinder, and an engine including the same .

FIG. 7 is a configuration diagram showing an overall configuration of a diesel engine with an EGR (exhaust gas recirculation) device used in Patent Document 1 (Japanese Patent Laid-Open No. 2005-299615) and the like.
In FIG. 7, exhaust gas combusted by a diesel engine (hereinafter referred to as an engine) denoted by reference numeral 100 passes through an exhaust valve (not shown) of each cylinder, an exhaust port 109, and an exhaust passage 199, and then an exhaust turbocharger. The exhaust turbine 120 is fed into the exhaust turbine 120 of the feeder 122 to drive the exhaust turbine 120.

On the other hand, the air compressed by the compressor 121 driven coaxially by the exhaust turbine 120 passes through the air supply pipe 125, is cooled by the air cooler 134, passes through the throttle valve 123, passes through the air supply passage 200, and is supplied to each cylinder. Enters the air port 108 and enters the air supply valve (not shown) through the air supply port 108.
Further, a part of the engine exhaust gas is extracted from the branch point 110a of the exhaust passage 199 and is returned to the junction point 110b of the supply passage 200 on the downstream side of the throttle valve 123 through the EGR passage 110 and the EGR cooler 124. The passage area of the EGR passage 110 is adjusted by an EGR valve 112.

In a diesel engine with an EGR device as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2005-299615) and the like, for example, as shown in FIG. In the case of the engine with 122, since it is often higher than the exhaust pressure of the engine, the opening of the throttle valve 123 is throttled to lower the supply air pressure so that EGR gas can easily flow into the supply passage 200. .
Further, in Patent Document 2 (Japanese Patent Laid-Open No. 2005-273558), a protrusion for adjusting the flow rate is provided in the middle portion of the air supply passage, and mixing and stirring on the air supply port outlet side are performed by the throttling effect of the protrusion. I have control.

JP 2005-299615 A JP 2005-273558 A

  In a diesel engine with an EGR device, low-oxygen concentration EGR gas is mixed into the supply side and low-oxygen concentration combustion is performed in the cylinder. In an exhaust turbocharged diesel engine, as described above, Since the exhaust pressure of the engine is almost the same as the supply air pressure of the engine, the exhaust pressure of the engine does not satisfy the supply pressure of the engine, and therefore the EGR gas on the exhaust side of the engine returns to the supply passage side of the engine. It is hard to do.

For this reason, in Patent Document 1 (Japanese Patent Laid-Open No. 2005-299615), for example, as shown in FIG. 5 on page 9 of the publication, the opening of the throttle valve 123 is reduced to lower the supply air pressure and the confluence 110b. The EGR gas is adjusted so as to easily flow into the supply air passage 200 in the relationship of engine exhaust pressure> engine supply pressure.
Therefore, in such a prior art, the opening degree of the throttle valve 123 is reduced in order to reduce the supply pressure of the engine. However, the loss due to the decrease in the supply pressure is large, and the inflow of EGR gas is promoted. In addition, the engine performance is sacrificed, and the pumping loss increases when the exhaust pressure is reduced.

  In view of the problems of the prior art, the present invention is connected to an EGR take-out portion and an EGR introduction portion of each cylinder without using a means for reducing engine performance such as throttle valve opening adjustment in a diesel engine with an EGR device. An object of the present invention is to provide an air supply device for an engine with an EGR device that allows EGR gas to flow smoothly into the air supply port at all times by providing a common EGR distribution chamber.

  The present invention solves such a problem, and includes an EGR passage that recirculates a part of the exhaust gas of an engine into an air supply port that supplies air to each of the cylinders, and the EGR passage includes one cylinder. In the air supply device for an engine with an EGR device configured to supply the EGR gas extracted from the EGR extraction portion to the EGR introduction portion of another cylinder, the EGR extraction portion is provided in the exhaust port of each cylinder, In addition to providing the EGR introduction portion in the air supply port of each cylinder, a common EGR distribution chamber connected to each EGR take-out portion and each EGR introduction portion is provided, and an electromagnetic valve is provided in each EGR take-out passage and each EGR introduction passage. And a solenoid valve control device that controls opening and closing of the solenoid valve in accordance with the exhaust timing and the supply timing of each cylinder. Motomeko 1).

  In the present invention, preferably, an engine operating condition detecting means for detecting either or both of the engine load and the engine speed of the engine is provided, and the EGR distributor is connected to the engine load and the engine operating condition detecting means. The opening / closing timing and the opening / closing period of each electromagnetic valve are controlled based on the detection signal of either or both of the engine speeds (Claim 2).

  An engine according to the present invention includes the air supply device for an engine with an EGR device according to claim 1 or 2.

  According to the present invention, the EGR extraction portion is provided in the exhaust port of each cylinder, the EGR introduction portion is provided in the air supply port of each cylinder, and the EGR extraction portion and the EGR introduction portion are connected in common. Since an EGR distribution chamber is provided, an electromagnetic valve is provided in each EGR extraction passage and each EGR introduction passage, and an electromagnetic valve control device that controls opening and closing of the electromagnetic valve in accordance with the exhaust timing and the supply timing of each cylinder is provided. EGR can be guided to the distribution chamber from the exhaust port of each cylinder at the exhaust timing, and EGR with constant pressure is always stored in the EGR distribution chamber, and from there, the supply timing to the supply port of each cylinder Therefore, there is no variation in the EGR supply amount between the cylinders, and stable supply is possible.

  In the present invention, an engine operating condition detecting means for detecting either or both of the engine load and the engine speed of the engine is provided, and either or both of the engine load and the engine speed from the engine operating condition detecting means are detected. By controlling the opening / closing timing and the opening / closing period of each solenoid valve based on the signal, the opening / closing timing of the solenoid valve is detected by the detection signal of either or both of the engine load and the engine speed from the engine operating condition detecting means. Since the opening and the opening are controlled, the amount of EGR gas introduced from the exhaust port to the EGR distribution chamber and the amount of EGR gas from the EGR distribution chamber to each cylinder are adapted to the detection signal of the engine load and the engine speed. And can be controlled accurately, so that an appropriate amount of EGR can be supplied under each condition, resulting in improved performance.

  In addition, according to the present invention, an engine that includes the above-described air supply device for an engine with an EGR device is configured so that EGR gas can flow into the intake port smoothly and smoothly without degrading engine performance. Can provide.

It is sectional drawing which shows the supply and exhaust structure around the cylinder of the diesel engine with an EGR (exhaust gas recirculation) apparatus concerning embodiment of this invention. It is the schematic which shows the planar arrangement | positioning of each cylinder which shows the basic composition of the EGR apparatus of this invention. (A) is a table | surface which shows the ignition order of # 1-# 6 cylinder, (B) is a relationship arrangement | positioning table | surface along the ignition order of the exhaust port 109 and the air supply port 108 of each cylinder. It is a change line chart by the crank angle of the cylinder pressure of each cylinder in the basic composition of the EGR device of the present invention. FIG. 3 is a view corresponding to FIG. 2 showing a planar arrangement of each cylinder showing a reference example of the present invention. FIG. 3 is a view corresponding to FIG. 2 showing a planar arrangement of each cylinder showing the first embodiment of the present invention. It is a block diagram which shows the whole structure of the conventional diesel engine with an EGR (exhaust gas recirculation) apparatus.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to specific examples unless otherwise specifically described. Only.

FIG. 1 is a cross-sectional view showing a supply and exhaust configuration around a cylinder of a diesel engine with an EGR (exhaust gas recirculation) device.
In FIG. 1 and FIG. 7 showing the prior art, in a diesel engine denoted by reference numeral 100 (hereinafter referred to as an engine), exhaust gas after being burned by fuel injection from a fuel injection valve 107 mounted on a cylinder head 111 is Then, after passing through the exhaust valve 105 and the exhaust port 109 of each cylinder, the exhaust turbine is sent to the exhaust turbine 120 of the exhaust turbocharger 122 (see FIG. 7) through the exhaust passage 199 to drive the exhaust turbine 120.

  On the other hand, the air compressed by the compressor 121 coaxially driven by the exhaust turbine 120 (see FIG. 7) passes through the air supply pipe 125, is cooled by the air cooler 134, passes through the throttle valve 123, and passes through the air supply passage 200. Through the air supply port 108 and the air supply valve 104 and into the combustion chamber 103, and the piston 101 into which the piston ring 106 is inserted after being combusted is disposed along the inner surface of the cylinder liner 102. Press down.

In the prior art of FIG. 7, the EGR gas is branched from the branch point 110a of the exhaust passage 199. However, in this embodiment, the branch is made at the branch point 110a ′ of the exhaust port 109 as shown in FIG. ing.
Further, a part of the engine exhaust gas is extracted from the branch point 110a ′ of the exhaust port 109 and discharged as EGR gas. The EGR gas is extracted from the EGR extraction unit 110c.
The air supply port 108 is provided with an EGR introduction part 110d into which the EGR gas taken out by the EGR extraction part 110c is introduced, and the EGR gas is joined to the supply air at a junction point 110b ′.
The EGR take-out part 110c and the EGR introduction part 110d are connected by an EGR passage 110.
The EGR gas returns to the junction 110b of the supply port 108 on the downstream side of the throttle valve 123 (see FIG. 7) through the EGR passage 110 and the EGR cooler 124. The passage area of the EGR passage 110 is adjusted by an EGR valve 112.

  In the present invention, the EGR passage 110 supplies the EGR gas taken out from the EGR take-out portion 110c of one cylinder to the EGR introduction portion 110d of another cylinder through the EGR passage 110. Are connected to the EGR extraction part 110c of one cylinder to the EGR passage 110 to the EGR introduction part 110d of another cylinder.

(Basic configuration)
FIG. 2 shows a basic configuration of the EGR apparatus of the present invention. FIG. 3A is a table showing the firing order of the # 1 to # 6 cylinders, and FIG. 3B is a relational arrangement diagram along the firing order of the exhaust port 109 and the air supply port 108 of each cylinder. FIG. 4 is a graph showing the change in cylinder pressure of each cylinder according to the crank angle (the cylinders # 3, # 5, and # 6 are omitted).

In FIG. 2, the present invention sets the connection of the EGR extraction part 110 c to EGR passage 110 of one cylinder to the EGR introduction part 110 d of another cylinder as follows.
In FIG. 2, 1, 2, 3, 4, 5, and 6 indicate # 1, cylinder # 2, cylinder # 3, cylinder # 4, cylinder # 5, and cylinder # 6, respectively.

In other words, taking the connection between the # 1 cylinder and the # 4 cylinder as an example,
Along with the ignition timing (FIG. 3B) of each cylinder, the exhaust pressure (Pz1 in FIG. 4) when supplying EGR gas from a certain cylinder, for example, the # 1 cylinder, and the # 4 cylinder according to the order of the ignition timing Two cylinders (exhaust stroke zone Z1 for opening the exhaust valve of the # 1 cylinder and supply of the opening of the intake valve for the # 4 cylinder) in which the pressure difference (Pz1-Pz2) from the supply pressure (Pz2 in FIG. 4) increases. As shown in FIGS. 1 and 2, the EGR extraction portion 110c is provided on the exhaust port 109 side of the # 1 cylinder, and the air supply port 108 side of the other # 4 cylinder is used. An EGR introduction part 110d is provided, and the EGR extraction part 110c and the EGR introduction part 110d are connected by an EGR passage 110 provided with an EGR cooler 124 and an EGR valve 112.

For the other cylinders, as shown in FIG. 3B, the # 2 cylinder is the # 6 cylinder, the # 3 cylinder is the # 5 cylinder, the # 4 cylinder is the # 2 cylinder, # 5 The cylinder is connected to the # 1 cylinder and the # 6 cylinder is connected to the # 3 cylinder through the EGR passage 110, respectively.
In FIG. 2, the supply air from the supply manifold 114 is diverted to the supply port 108 of each cylinder, and the exhaust from the exhaust port 109 of each cylinder is merged by the exhaust manifold 113.

  According to such a basic configuration, the exhaust pressure Pz1 at the time of supply of EGR gas in a certain cylinder (for example, # 1 cylinder) and the supply pressure Pz2 of another cylinder (for example, # 4 cylinder) in accordance with the order of the ignition timing Select two cylinders (# 1 cylinder and # 4 cylinder) that increase the pressure difference (Pz1-Pz2), that is, select the cylinder in the supply stroke and the cylinder in the exhaust stroke from the ignition sequence, An EGR extraction part 110c is provided on the exhaust port 109 side of one cylinder, an EGR introduction part 110d is provided on the air supply port 108 side of the other # 4 cylinder, and the EGR extraction part 110c and EGR of the two cylinders are provided in the EGR passage 110. The introduction part 110d is connected.

  With the above connection, it is possible to select a combination that always has a large pressure difference (Pz1-Pz2) between the exhaust and the supply for the exhaust port 109 side and the supply port 108 side of each cylinder. Can be supplied to the cylinder on the air supply port 108 side smoothly at all times.

  Therefore, according to this basic configuration, when supplying EGR gas, the relationship between the pressure difference between the exhaust gas and the supply air (Pz1-Pz2), that is, the relationship between the engine exhaust pressure> the engine supply pressure can be maintained. In order to reduce the supply air pressure of the engine, no means for reducing the engine performance, such as reducing the opening of the throttle valve 123, is used, so there is no loss due to a reduction in the supply air pressure and the inflow of EGR gas is promoted. Therefore, the relationship of engine exhaust pressure> engine supply air pressure can always be established without sacrificing a decrease in engine performance, so that EGR gas can flow into the supply port smoothly and constantly.

In addition, in this basic configuration, as described above, the engine is selected by a low-cost means in which a cylinder having a high exhaust pressure Pz1 and a cylinder having a low supply pressure Pz2 are selected and connected through the EGR passage 110. An air supply device for an engine with an EGR device that can smoothly flow EGR gas into the air supply port 108 at all times without reducing the performance can be obtained.
Further, when the exhaust turbine PZ1 is increased by enlarging the throttle of the exhaust turbine, Pz1 can be reduced by the pressure difference (Pz1-Pz2) so that Pz1 = Pz2, so that the pumping loss of the exhaust system Can be reduced.

(Reference example)
FIG. 5 is a diagram corresponding to FIG. 2 showing a planar arrangement of each cylinder showing a reference example of the present invention.
In this reference example, in addition to the same coupling as the basic configuration, the configuration is as follows.
That is, in such a reference example, an electromagnetic wave that opens and closes the EGR passage 110 and adjusts the opening degree of the EGR passage 110 in each EGR passage 110 connecting the two cylinders (for example, # 1 cylinder and # 4 cylinder). One valve 4a, 4b, 4c, 4d, 4e, 4f is provided for each of the two cylinders (for example, # 1 cylinder and # 4 cylinder).

  In the reference example, the load detector 2 for detecting the engine load of the engine and the rotation speed detector 3 for detecting the engine speed are provided, and the detected value of the engine load and the detected value of the engine speed are set as Each electromagnetic valve 4a, 4b, 4c, 4d, 4e, 4f is input to an electromagnetic valve control device 5 that controls the opening / closing timing and the opening / closing period.

The electromagnetic valve control device 5 determines the opening / closing timing and the opening / closing period of each of the electromagnetic valves 4a, 4b, 4c, 4d, 4e, 4 from the load detector 2 and the engine speed detection value of the engine speed detector 3 and the engine. Correction is made by the detection signal of the rotation speed detection value.
As a result, the exhaust side and the supply side of each cylinder can be opened at the timing when the pressure difference (P1-P2) between the exhaust and the supply becomes large, and the exhaust of the supply air is always compared to the case where the cylinders are always in communication. It is possible to stop the EGR supply at an unnecessary time depending on the backflow to the system or the operating state, and it is possible to reduce exhaust gas and fuel consumption under a wide range of conditions.

The load detector 2 and the rotation speed detector 3 may be any one.
Other configurations are the same as the basic configuration (FIG. 2), and the same members are denoted by the same reference numerals.

(First embodiment)
FIG. 6 is a view corresponding to FIG. 2 showing a planar arrangement of each cylinder showing the first embodiment of the present invention.
The first embodiment is configured as follows.
That is, in the first embodiment, the EGR extraction part 110c is provided on the exhaust port 109 side of each cylinder, and the EGR introduction part 110d is provided on the supply port 108 side of each cylinder.
Then, an EGR distribution chamber 1 is provided, and the EGR take-out portion 110c of the exhaust port 109 of each cylinder is connected to the EGR distribution chamber 1, and further, the EGR introduction portion 110d of the air supply port 108 of each cylinder is connected to the EGR distribution chamber 1. Connected.
Solenoid valves 6a, 6b, 6c, 6d, 6e, and 6f are respectively provided at the connection portions between the EGR take-out portion 110c and the EGR distribution chamber 1 of each cylinder, and the connection portions between the EGR introduction portion 110d and the EGR distribution chamber 1 are respectively provided. Solenoid valves 8a, 8b, 8c, 8d, 8e, and 8f are provided. And each solenoid valve 6a-6f, 8a-8f is input into the solenoid valve control apparatus 5 which controls opening and closing timing and opening and closing period.

  The solenoid valves 6a, 6b, 6c, 6d, 6e, and 6f installed at the connection part between the EGR extraction part 110c and the EGR distribution chamber 1 of each cylinder are controlled so as to open in synchronization with the exhaust timing of each cylinder. The solenoid valves 8a, 8b, 8c, 8d, 8e, and 8f installed at the connection portion between the EGR introduction portion 110d of each cylinder and the EGR distribution chamber 1 are opened in synchronization with the supply timing of each cylinder. It has become.

  In this way, the EGR distribution chamber 1 opens and guides EGR gas at the exhaust timing of the highest pressure in the exhaust port of each cylinder, so that EGR with constant pressure is always stored in the EGR distribution chamber. Therefore, the supply port of each cylinder can be supplied at the supply timing, so that the supply of EGR gas can be stably performed without variation in the amount of EGR supply between the cylinders.

  In the first embodiment, the load detector 2 for detecting the engine load of the engine and the rotation speed detector 3 for detecting the engine speed are provided, and the detected value of the engine load and the detected value of the engine speed are obtained. , Input to the solenoid valve control device 5.

Therefore, according to the first embodiment, based on the detection signal of the engine load and the engine speed from the load detector 2 and the rotation speed detector 3, the intake from the EGR take-out portion 110c to the EGR distribution chamber 1; The supply from the EGR distribution chamber 1 to the EGR introduction part 110d can be adjusted.
That is, in the EGR distribution chamber 1, it can be stored according to the detection signal of the engine load and the engine speed, and further supplied to the air supply port 108 according to the detection signal of the engine load and the engine speed. The supply amount of EGR gas can be controlled accurately and freely.

For example, EGR is not supplied at high engine speed and high rotation, but the exhaust pressure rises, so the exhaust gas at that time controls the valve opening timing and opening of the solenoid valves 6a, 6b, 6c, 6d, 6e, 6f. The EGR distribution chamber 1 stores the high-pressure exhaust gas stored in the EGR distribution chamber 1 when the engine is in the required operating state or EGR at low load and low rotation. By controlling the valve opening timing and opening degree of 8c, 8d, 8e, and 8f and supplying them to the supply port 108, high-pressure exhaust gas can be supplied as EGR gas, and efficient control of EGR gas becomes possible.
The load detector 2 and the rotation speed detector 3 may be any one.
Other configurations are the same as the basic configuration (FIG. 2), and the same members are denoted by the same reference numerals.

  According to the present invention, in a diesel engine with an EGR device, a common EGR distribution connected to an EGR take-out portion and each EGR introduction portion of each cylinder without using a means for reducing engine performance such as adjustment of the opening degree of a throttle valve. By providing the chamber, it is possible to provide an air supply device for an engine with an EGR device that can smoothly flow EGR gas into the air supply port at all times.

DESCRIPTION OF SYMBOLS 1 EGR distribution chamber 2 Load detector 3 Revolution detector 4a-4f Solenoid valve 6a-6f Solenoid valve 8a-8f Solenoid valve 5 Solenoid valve control device 100 Engine (4-cycle diesel engine)
DESCRIPTION OF SYMBOLS 101 Piston 102 Cylinder liner 103 Combustion chamber 104 Supply valve 105 Exhaust valve 107 Fuel injection valve 108 Supply port 109 Exhaust port 110 EGR passage 110c EGR extraction part 110d EGR introduction part 110a, 110a 'Branch point 110b, 110b' Confluence 112 EGR valve 122 Exhaust turbocharger 123 Throttle valve 199 Exhaust passage 200 Air supply passage

Claims (3)

An EGR passage that recirculates a part of the exhaust gas of the engine into an air supply port that supplies air to each of the cylinders. The EGR passage takes EGR gas taken out from an EGR take-out portion of one cylinder, In an air supply device for an engine with an EGR device configured to be supplied to an EGR introduction portion of another cylinder,
The EGR extraction part is provided in the exhaust port of each cylinder, the EGR introduction part is provided in the air supply port of each cylinder, and a common EGR distribution chamber to which each of the EGR extraction part and each EGR introduction part is connected is provided. provided, each of the with the EGR distribution chamber to the connecting portion between the EGR extraction City section and the respective EGR introduction part provided an electromagnetic valve, which controls the opening and closing of the electromagnetic valve along the exhaust timing and supply timing of each cylinder electromagnetic Rutotomoni a valve control unit,
The solenoid valve control means is a control means for opening each solenoid valve provided at a connection portion between the EGR distribution chamber and each EGR take-out portion at least at an exhaust timing when the pressure of each cylinder is the highest. air supply device of an EGR system with an engine, characterized in that it.   Engine operating condition detection means for detecting either or both of the engine load and the engine speed of the engine is provided, and based on the detection signal of either or both of the engine load and engine speed from the engine operating condition detection means The air supply device for an engine with an EGR device according to claim 1, wherein the opening / closing timing and the opening / closing period of each electromagnetic valve are controlled. An engine comprising the air supply device for an engine with an EGR device according to claim 1 or 2.

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