JPH01195919A - Engine provided with pressure wave supercharger - Google Patents

Abstract

PURPOSE:To improve scavenge efficiency and to improve misfire through reduction of internal EGR by providing a variable pulley unit for lowering the rotary ratio of a pressure wave supercharger with respect to an engine output shaft and a control means therefor. CONSTITUTION:Output shaft, i.e. crankshaft 2, of a Diesel engine is coupled with the rotor shaft 7a of a pressure wave supercharger 6 through crank pulley and belt 4 and a rotor pulley 5. A variable pulley unit 2 for lowering the rotary ratio of a pressure wave supercharger 6 with respect to the crankshaft 2 is further provided. A control means for operating a variable pulley unit 21 under high rotation zone in low load region is also provided. The control means comprises a spring 33 and a flyweight 26. By such arrangement, scavenge efficiency is improved and internal EGR is reduced resulting in the improvement of misfire.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an engine with a pressure wave supercharger that transmits pressure wave energy of exhaust gas to intake air, compresses the intake air, and performs supercharging.

(Prior Art) Conventionally, as the above-mentioned pressure wave supercharged engine, there is a diesel engine having a structure as shown in FIG. 5, for example.

That is, a rotor 53 is provided on a crankshaft 52 of a diesel engine 51 and is rotatable via a boob and a belt (not shown), and this rotor 53 is provided with a large number of partition walls 55 ( In FIG. 5, the rotation of the rotor 53 is replaced with downward movement) are arranged radially, and the air casing 56 at one end of the rotor 53 has an intake inlet 57 and an intake outlet. 58, an exhaust inlet 6o and an exhaust outlet 61 are formed in the gas casing 59 at the other end of the rotor 53, an intake manifold 62 is connected to the intake outlet 58, and an exhaust inlet 60 is connected to the exhaust inlet 60. This is an engine equipped with a pressure wave supercharger, in which an exhaust manifold 63 is connected to the exhaust manifold 63.

In this pressure wave supercharged engine, as the rotor 53 rotates according to the engine speed, intake air drawn into the cells 54 of the rotor 53 from the intake port 57 is transferred from the exhaust port 60 to the cells 54 of the rotor 53. 54, the pressure wave energy of the exhaust gas is transmitted to the intake air, the intake air is compressed and accelerated, and is supercharged and discharged from the intake air outlet port 58.
The exhaust gas remaining inside is discharged from the exhaust outlet 61, and
Scavenging is repeated by introducing intake air into the cell 54 described above from the intake air introduction port 57.

However, the pressure wave supercharged engine described above has the problem of misfire at high engine speeds in a low load range.

In other words, the exhaust pressure wave propagating at the speed of sound is reflected as a pressure wave at the fixed end and reversed as an expansion wave at the open end. As a result, an ideal boundary line between the intake air and the exhaust gas is formed as shown by the dotted line a in FIG. , due to the above-mentioned timing mismatch and also because the exhaust pressure is low, for example about 1.3 bar, the cell 54
The internal pressure decreases, and the exhaust gas release pressure decreases,
The exhaust gas remains in the cell 54, and the boundary line between the intake air and the exhaust gas becomes as shown by the dotted line in FIG. to EG
Since the fuel becomes R and is recirculated to the intake side, there is a problem in that a misfire occurs.

In such an engine with a pressure wave supercharger, as described in, for example, Japanese Utility Model Application Publication No. 61-36131, a boolean pressure system that changes the boolean ratio for driving the pressure wave supercharger with the engine has conventionally been used. a variable device, a load detection means for detecting the load state of the engine, and a control means for receiving the output of the load detection means and controlling the pulley ratio variable device so that the boolean ratio becomes larger in a lower load region. There is an engine equipped with a pressure wave supercharger that is configured to improve NOx and fuel efficiency by varying the rotation ratio with respect to the engine speed, but it is necessary to improve the misfire in the high rotation range in the low load range mentioned above. I can't.

(Objective of the Invention) An object of the present invention is to provide an engine with a pressure wave supercharger that can better prevent misfires as described above at high rotation speeds in a low load range where exhaust energy is small.

(Structure of the Invention) The present invention includes a rotor that is rotatably supported within a case and has a large number of partition walls that form a large number of small chambers arranged radially, and an air intake formed in an air casing at one end of the rotor. It has an inlet and an intake outlet, and an exhaust inlet and an exhaust outlet formed in the gas casing on the other end side of the rotor, and transmits the pressure wave energy of the exhaust to the intake as the rotor rotates, An engine with a pressure wave supercharger that supercharges intake air, the engine includes a rotation ratio reducing means for reducing the rotation ratio of the pressure wave supercharger to the engine output shaft, and a rotation ratio reduction means for reducing the rotation ratio in a high rotation range in a low load range. The present invention is characterized in that the engine is equipped with a pressure wave supercharger and includes a control means for activating the pressure wave supercharger.

(Effects of the Invention) According to the present invention, the above-mentioned control means operates the rotation ratio reducing means at high rotation speeds in a low load range to reduce the rotation ratio of the pressure wave supercharger to the engine output shaft, thereby reducing the pressure. Since the rotation of the rotor of the wave supercharger is reduced, the opening/closing timing of each boat of the intake inlet, intake outlet, exhaust inlet, and exhaust outlet almost matches the timing of pressure wave propagation, and the intake air and Since the boundary line with the exhaust gas approaches the ideal state, the residual gas discharge in the small chamber of the rotor, that is, the scavenging efficiency, becomes good, which has the effect of reducing internal EGR and improving misfires. .

(Example) An embodiment of the present invention will be described in detail below with reference to the drawings.

The drawings show an engine equipped with a pressure wave supercharger, and in FIGS. A feeder 6 is connected to a rotor shaft 7a of a so-called pressure wave supercharger.

The above-mentioned pressure wave supercharging 16 rotatably supports the above-mentioned 0-tough in a case (not shown), as shown in FIG. 1 with the rotation of the rotor 7 replaced by downward movement.

In addition, the rotor 7 has a large number of cells 8 as small chambers.
In addition, the air casing 10 at one end of the rotor 7 is provided with an intake inlet 11 and an intake outlet 12, and the gas at the other end is disposed radially. The casing 13 is formed with an exhaust inlet 14 and an exhaust outlet 15, respectively.

Furthermore, an air cleaner is installed in front of the above-mentioned intake inlet 11, and an intake manifold 16 is installed in the rear of the intake outlet 12.
At the same time, an exhaust manifold 17 is connected to the front side of the exhaust gas introduction port 14, and a silencer is connected to the rear side of the exhaust gas discharge port 15.

In addition, 18 in FIG. 1 is a compression pocket, 19 is an expansion pocket, and 20 is a gas pocket.

The above-mentioned pressure wave supercharger 6 operates from the exhaust inlet 14 to the intake air taken into the cell 8 of the rotor 7 from the intake inlet 11 as the rotor 7 rotates according to the engine speed. The exhaust gas is caused to flow into the cell 8, and the pressure wave energy of the exhaust gas propagated at the speed of sound is transmitted to the intake air to compress the intake air.
While accelerating and supercharging from the intake/discharge port 12,
The scavenging process is repeated by discharging the exhaust gas remaining in the wood cell 8 from the exhaust outlet 15 and introducing intake air into the cell 8 from the intake inlet 11.

By the way, the variable pulley device 21 as a rotation ratio reducing means for lowering the rotation ratio of the pressure wave supercharger 6 to the crankshaft 2 is constructed as shown in FIG.

That is, a fixed groove wheel 22 is fitted and fixed to the crankshaft 2 on the side of the diesel engine 1, and a movable groove wheel 24 that is movable by the centrifugal force of the flyweight 23 is provided to the fixed groove wheel 22, so that the above-mentioned crank pulley On the other hand, a fixed groove wheel 25 is fitted and fixed to the rotor shaft 7a on the side of the pressure wave supercharger 6, and a movable groove wheel is movable with respect to the fixed groove wheel 25 by the centrifugal force of a flyweight 26. 2
7 to constitute the aforementioned rotor pulley 5, and a belt 4 is stretched between the rotor pulley 5 and the aforementioned crank pulley 3 to constitute the aforementioned variable pulley system@21 so-called V-belt type continuously variable transmission. are doing.

Further, a fixed cover 28 is attached to the shaft end of the above-mentioned crankshaft 2 serving as the drive side (driving side), and the above-mentioned flyweight 23.23 is disposed on this fixed cover 28 via a fulcrum 29.29. , and a spring 30 is stretched between the fixed cover 28 and the end surface of the cylindrical shaft portion of the movable grooved sheave 24.

On the other hand, a fixed disk 31 is attached to the back side of the movable groove wheel 27 on the above-mentioned rotary shaft 7a as the driven side (driven side), and the above-mentioned fly weight 26 is connected to the fixed disk 31 via a fulcrum 32.32. .26 is disposed, and a spring 33 is stretched between the facing surfaces of the movable groove sheave 27 and the fixed groove sheave 25 described above.

Then, this spring 33 and the above-mentioned fly weight 2
6 and 26 constitute a control means for operating the variable boolean device 21 in a high rotation range of a low load range.

That is, when the setting spring force of the spring 33 mentioned above is F1, and the force in the thrust direction due to the centrifugal force of the flyweights 26.26 is F2, as shown in FIG. The configuration is such that when the thrust force F2 of the flyweight 26 exceeds the spring force F1 of the spring 33, the above-mentioned variable boob device @21 is operated to lower the rotation ratio of the pressure wave supercharger 6 with respect to the crankshaft 2. ing.

Regarding this point, the relationship between the set spring force of the spring 30 and the force in the thrust direction caused by the centrifugal force of the flyweight 23 is similarly set.

The illustrated embodiment is constructed as described above, and its operation will be explained below.

The rotation speed of the diesel engine 1 is determined by the set spring force F1 of the spring 3'3 shown in FIG. 3 and the flyweight 26.2.
When reaching a preset high rotation range, for example 4300 rpm, as the point of intersection with the thrust force F2 of 6, the above-mentioned 8 forces Fl and F2 become equal at this point, and when the engine speed reaches the above-mentioned 4300 rpm or higher, the fly weight 26
．． The thrust force F2 of 26 exceeds the set spring force F1 of the spring 33.

Therefore, in the high rotation range mentioned above, the flyweight is 26.26.
Due to the thrust force F2, the movable groove wheel 2 of the rotor pulley 5
7 pivots in the direction of arrow C in FIG. 2 to increase the pulley diameter of the rotor pulley 5.

In addition, in the above-mentioned high rotation range, the thrust force of the fly weight 23.23 on the crankshaft 2 side causes the crank pulley 3 to
The movable grooved sheave 24 is pivoted in the direction of arrow d in FIG. 2 to reduce the diameter of the bore of the crank pulley 3.

For this reason, the rotation of the rotor 7 of the pressure wave supercharger 6 with respect to the crankshaft 2 decreases, for example, from about 4 times the normal rotation to about 3 to 3.5 times.

In this way, the rotation of the rotor 7 of the pressure wave supercharger 6 decreases in the high speed range of the low load range, so the intake inlet 1 shown in FIG.
1, intake outlet 12, exhaust inlet 14, exhaust outlet 15
The opening/closing timing of each boat and the timing of pressure wave propagation approximately match, and the boundary line between intake air and exhaust gas approaches the ideal state shown by dotted line a in Figure 1.
The discharge of the residual gas in the cell 8 of the rotor 7 described above, that is, the scavenging effect is improved, and the internal EGR is reduced as shown by the solid line α in the characteristic diagram of FIG. 4, and as a result, the misfire can be improved. There is an effect that can be done.

In the correspondence between the structure of the present invention and the above-described embodiment, the small space of the present invention corresponds to the cell 8 of the embodiment, the engine output shaft corresponds to the crankshaft 2, and the rotational conversion reducing means corresponds to the variable pulley device 21, and the control means includes the spring 33 and the flyweight 26.
However, the present invention is not limited to the configuration of the above-described embodiment.

For example, by interposing an electromagnetic clutch on either the crankshaft 2 or the rotor shaft 7a and controlling the above-mentioned electromagnetic clutch ON and OFF in a low load range and high rotation range, pressure waves on the crank @2 can be generated. The configuration may be such that the rotation ratio of supercharging Ia6 is reduced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a system diagram of an engine equipped with a pressure wave supercharger in which rotation of the rotor is replaced with downward movement; FIG. 2 is an explanatory diagram of a variable pulley device; Fig. 3 is a characteristic diagram showing the relationship between spring force and flyweight thrust force with respect to engine speed, and Fig. 4 is an EGR characteristic diagram under no load. 2... Crankshaft 6... Pressure wave supercharger 7.
...Rotor 8...Cell 9...Partition wall 10...Air casing 11...Intake inlet 12...Intake discharge port 13...Gas casing 14...Exhaust inlet 15...・Exhaust outlet
21... Variable boolean device 26... Fly weight 33... Spring Figure 2 Figure 3

Claims (1)

[Claims] (1) A rotor that is rotatably supported within a case and has a number of partition walls arranged radially to form a number of small chambers, and an intake inlet and an intake outlet formed in an air casing at one end of the rotor. and an exhaust inlet and an exhaust outlet formed in the gas casing at the other end of the rotor, and supercharges the intake by transmitting the pressure wave energy of the exhaust to the intake as the rotor rotates. An engine with a pressure wave supercharger, comprising a rotation ratio reducing means for reducing the rotation ratio of the pressure wave supercharger to the engine output shaft, and a control means for operating the rotation ratio reducing means in a high rotation range in a low load region. An engine with a pressure wave supercharger.