JPH06212986A - Supercharger of engine - Google Patents

Abstract

PURPOSE:To increase a primary compression ratio by paritioning the interior of a crank case into two air chambers, communicating one air chamber with a fresh air introducing part and taking the other air chamber as a compression chamber to be communicated with a combustion chamber to form a displacement compressor taking a connecting rod as a needle. CONSTITUTION:When a crankshaft 2 is rotated, a piston 4 is reciprocated in a cylinder hole 5, and a connecting rod 7 is oscillated in a storing part and moved up and down to make pendulum motion. The piston 4 is positioned in the vicinity of the lower dead point and the crankshaft 2 is rotated clockwise, whereby the capacity in one air chamber B is decreased, so that the air in the interior is compressed. At this time, when a notch 17a of a crank web 17 confronts with a discharge passage 24, the compressed air in the air chamber B is pushed out to the discharge passage 24. The capacity in the other air chamber A is increased so that fresh air is introduced into the interior thereof from an air suction pipe 26. Further, the compressed air of the discharge passage 24 is mixed with a fuel by a fuel supply means 15 and forced into a combustion chamber 9 from an intake valve 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercharging device for an engine which supercharges by utilizing a change in volume in a crank chamber.

[0002]

2. Description of the Related Art Conventionally, as a supercharger of a crankcase supercharging system for supercharging a crank chamber as a compression chamber, a positive displacement compressor having an engine piston as a mover and a crank chamber as a compression chamber is formed. Some compressors pump intake air into the intake passage on the intake port side. This type of supercharger has a structure in which the air-fuel mixture is sucked into the crank chamber when the piston moves up, and the air-fuel mixture is pushed out to the intake passage on the intake port side when the piston moves down.

That is, while the crankshaft makes one revolution, supercharging is performed by the stroke volume of the engine. When the supercharging device of the crankcase supercharging system is applied to a 4-cycle engine, the intake stroke is increased. The supercharged amount is 2
Doubled.

[0004]

However, in the conventional crankcase supercharging type supercharging device configured as described above, the engine output could actually be improved only by several tens of percent. This is because the dead volume and passage resistance in the crank chamber are large, and the supercharged air-fuel mixture expands due to the heat of the engine and the charging efficiency is reduced.

Further, in order to improve the supercharging performance and the engine output, it is sufficient to reduce the dead volume in the crank chamber and increase the primary compression ratio. The primary compression ratio is obtained by adding the stroke volume Vh to the case volume Vc when the piston is located at the bottom dead center and dividing the added value by Vc. However, since the volume between the crankshaft webs occupies a large portion of the case volume Vc, there is a limit to reducing the volume.

Further, as the crankcase supercharging type supercharging device, in addition to using the piston as the mover as described above, as shown in JP-A-2-136513, a kinetic vacuum is provided in the crankcase. Some also formed a compressor equivalent to a pump.

In the supercharger disclosed in this publication, the rotor chamber is provided in the crankcase, and the rotor driven by the crankshaft is slidably mounted in the rotor chamber. Then, the rotation of the crankshaft causes the rotor to swing while swinging to perform a pendulum motion, and the volume of the compression chamber formed between the rotor and the inner surface of the rotor chamber changes, so that the intake air becomes a pressure accumulation chamber. It was structured to be pumped.

However, if the structure in which the intake air is pressure-fed using the rotor is adopted, the structure for connecting the rotor to the crankshaft becomes complicated, and the valve for closing the suction-side passage and the discharge-side passage is cranked. Must be provided on the case. Therefore, the structure becomes complicated and the number of parts increases.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to increase the primary compression ratio while suppressing increase in the number of parts and the structure, and to increase the crankcase supercharging. The purpose is to significantly increase capacity.

[0010]

In a supercharger for an engine according to the present invention, an inner peripheral wall on which a connecting rod is slidably contacted is formed on a crankcase, and the inside of the crankcase is set by a connecting rod at a crank angle other than near the top dead center. The air chamber is divided into two air chambers.One of these air chambers communicates with the fresh air introduction section, and the other air chamber communicates with the combustion chamber through the intake passage, and is communicated with this combustion chamber. A positive displacement compressor having the air chamber as the compression chamber and the connecting rod as the mover is formed, and the upstream end of the intake passage is opened at a position facing the crank web to be closed by the crank web. A cutout that connects the compression chamber and the intake passage is formed in a portion corresponding to the opening when the connecting rod in the outer peripheral portion of the web is at the end of the compression stroke. That.

[0011]

With each stroke of the crankshaft, fresh air is pumped into the combustion chamber by the stroke volume of the piston and the volume of the connecting rod accommodating portion, so that the primary compression ratio can be increased. Further, the supercharging device according to the present invention can be formed only by the members constituting the engine.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
It will be described in detail by. 1 is a cross-sectional view of a 4-cycle engine provided with a supercharger according to the present invention, and FIG. 2 is FIG.
2 is a sectional view taken along line II-II, FIG. 3 is a perspective view showing a schematic structure of a crankshaft used in the supercharger according to the present invention, FIG. 4 is a perspective view showing a schematic structure of a connecting rod, and FIG. FIG. 6 is a perspective view showing a schematic structure, and FIG. 6 is a perspective view showing a schematic structure of the engine body. FIG. 6 shows a state in which the engine body is broken along line VI-VI in FIG. Figure 7
FIG. 3 is a perspective view showing a schematic configuration of a supercharging device according to the present invention.

8 to 15 are sectional views for explaining the operation of the supercharger according to the present invention. FIG. 8 shows a state when the crankshaft is at the bottom dead center, and FIG. 9 shows the crankshaft. FIG. 10 shows a state of turning about 45 degrees from bottom dead center, FIG. 10 shows a state of turning 90 degrees, FIG. 11 shows a state of turning about 135 degrees, FIG. 12 shows a state of turning 180 degrees, and FIG. FIG. 14 shows a state of turning by about 225 degrees, FIG. 14 shows a state of turning by 270 degrees, and FIG. 15 shows a state of turning by about 315 degrees.

In these figures, reference numeral 1 is a four-cycle engine (hereinafter, simply referred to as an engine) provided with a supercharging device according to the present invention. In this embodiment, a single cylinder type having a simple structure is easy to understand. Show things. The engine 1 has a crankcase 3 composed of a lower case 3a and an upper case 3b that rotatably support a crankshaft 2 and a cylinder hole 5 into which a piston 4 is fitted, and is fixed on the crankcase 3. A cylinder block 6, a connecting rod 7 connecting the piston 4 to the crankshaft 2, and a cylinder head 8 fixed on the cylinder block 6.
Etc.

The cylinder head 8 is provided with a conventionally well-known valve operating mechanism. That is, the intake port 10 and the exhaust port 11 opening to the combustion chamber 9 are the intake valve 1
2 and the exhaust valve 13 are opened and closed. The upstream open end of the intake flow in the intake port 10 has an intake pipe 1 provided adjacent to the engine 1.
It is connected to 4. Further, an exhaust pipe (not shown) is connected to an open end of the exhaust port 11 on the downstream side of the exhaust flow, and is connected to the atmosphere via a silencer. Reference numeral 15 provided on the intake pipe 14 is a fuel supply device. The fuel supply device 15 is a carburetor equipped with a conventionally well-known fuel injection device and a fuel pressure pump.

Reference numeral 16 denotes a cam shaft for opening and closing the intake valve 12 and the exhaust valve 13 according to their respective opening and closing timings. The cam shaft 16 is rotatably supported by the cylinder head 8 and has a power transmission (not shown). It is connected to the crankshaft 2 via means.

The crankshaft 2 is, as shown in FIG.
It is formed by connecting a pair of crank webs 17, 17 formed in a disc shape via a crank pin 18. Two
Reference numeral a denotes a journal portion supported by the crankcase 3. The crank webs 17 have flat surfaces (end surfaces on the connecting rod side) facing each other, and the connecting rods 7, which will be described later, are spaced apart from each other with a size such that the connecting rods 7 can intervene between the crank webs 17.

Notches 17a are formed on the outer peripheral portions of both crank webs 17, respectively. These notches 17a, 17a are formed at the same position on both crank webs 17, and open at the connecting rod side end surface and the outer peripheral surface of the crank web 17. The position where these notches 17a are formed is located on the front side of the crankpin 18 in the rotational direction of the crankshaft 2.

The connecting rod 7 for connecting the piston 4 to the crankshaft 2 is formed in an elongated plate shape as shown in FIG. 4, and the end face of the crankshaft 2 which is oriented in the axial direction is formed flat. A sealing surface 7a is provided on the surface. Further, sealing surfaces 7b and 7c are provided at the large end portion of the connecting rod 7 through which the crank pin 18 penetrates and the small end portion thereof through which the piston pin 19 penetrates by forming each outer peripheral surface into an arc shape. ing. Further, the connecting rod side surface 7d formed in series on these seal surfaces 7b and 7c is formed in a straight line shape.

The piston 4 is formed as shown in FIG. 5, and is provided with a connecting rod insertion concave portion which opens to the skirt portion. The recess is configured such that the small end of the connecting rod 7 is slidably fitted therein.
Of the crankshaft in the axial direction, the sliding surface 4a is made of a flat surface with which the sealing surface 7a is in sliding contact, the sealing surface 7c of the outer peripheral surface of the small end is made of a concave curved surface, and the circumferential wall surface 4b.
And a side wall 4c formed of a flat surface.
Reference numeral 4d in FIG. 5 denotes a piston pin hole into which the piston pin 19 is fitted.

Crankshaft 2, formed as described above
Like the conventional engine, the connecting rod 7 and the piston 4 connect the large end of the connecting rod 7 to the crank web 17 of the crankshaft 2 via the crank pin 18, and connect the small end of the connecting rod 7 to the piston pin 19. It is assembled by connecting to the piston 4 via. In this crankshaft assembly, the seal surface 7a on the end surface of the connecting rod 7 in the crankshaft direction is the crank web 1 of the crankshaft 2.
7 and the sliding contact surface 4a of the piston 4, and the sealing surface 7c on the outer peripheral surface of the small end of the connecting rod 7 is the peripheral wall surface 4b of the piston 4.
Will be in sliding contact with.

As shown in FIG. 6, the engine body 20, which is an assembly of the crankcase 3 and the cylinder block 6, has a circular recess 21 into which the crank web 17 of the crankshaft 2 is rotatably fitted, and a cylinder hole. 5, a connecting rod accommodating portion 22 serving as a space in which the connecting rod 7 moves, a suction passage 23 provided in series in the connecting rod accommodating portion 22 for communicating the connecting rod accommodating portion 22 with the outside of the engine, and the circular recess 21. A discharge passage 24, which is open to the peripheral wall surface and the side surface of the engine body and connects the inside of the circular recess 21 to the outside of the engine, is formed in series. The inner diameter and the depth of the circular recess 21 are determined by the crank web 1
It is set to be slightly larger than the outer diameter and the thickness dimension of 7, and the crank web 17 is inserted into the circular recess 21 with a minute gap.

Reference numeral 25 in FIG. 6 is a bearing hole into which the journal portion 2a of the crankshaft 2 is inserted, and reference numeral 26 in FIG. 1 is an air suction tube.
The air suction pipe 26 is fitted in the suction passage 23 and fixed to the crankcase 3.

A side wall 22a of the connecting rod accommodating portion 22
Is formed so as to substantially correspond to the movement trajectory of the outer edge portion of the connecting rod 7 when the crankshaft 2 of the crankshaft assembly is mounted in the circular recess 21 and the piston 4 is reciprocated. By forming the connecting rod accommodating portion 22 on the engine body 20, the engine body 20 has a sliding contact surface 27 that is a flat surface with which the seal surface 7a of the crankshaft end surface of the connecting rod 7 is in sliding contact, and a large connecting rod 7. A peripheral wall surface 28 formed of a concave curved surface with which the seal surface 7b on the outer peripheral surface of the end portion is in sliding contact is formed.

That is, when the crankshaft assembly is attached to the engine body 20, when the piston 4 is located at the bottom dead center, the inside of the engine body 20 is partitioned into two chambers by the connecting rod 7 and the piston 4, as shown in FIG. ,
An air chamber A on the suction passage 23 side and an air chamber B on the discharge passage 24 side are provided.

The discharge passage 24 is formed in a bifurcated shape as shown in FIG. 2, one end communicates with the circular recess 21 through the two openings 24a, 24a, and the other end communicates with the crankcase 3. It has an opening on the side. The discharge passage 24 is connected to the intake inlet of the fuel supply device 15 via a communication pipe 29 attached to the crankcase 3. The two openings 24a, 24a are formed side by side in the axial direction of the crankshaft 2 so as to face the outer peripheral surfaces of the crank webs 17 provided on the crankshaft 2. The formation position is the same position in the circumferential direction of the circular recess 21, and is a position adjacent to the crankshaft side end of the side wall 22a of the connecting rod accommodating portion 22, as shown in FIG.

When the crankshaft assembly is mounted on the engine body 20 in which the discharge passage 24 is formed and the crankshaft 2 is rotated, the discharge passage 24 is opened and closed by the crank web 17 of the crankshaft 2. . That is, as shown in FIG. 7, the discharge passage 24 is closed by the crank web 17 when the outer peripheral surface of the crank web 17 faces the opening 24 a. When the crankshaft 2 rotates and the notch 17a of the crank web 17 faces the opening 24a as shown in FIG. 1, the discharge passage 24 communicates with the air chamber B side through the notch 17a. Like At this time, the air chamber B and the fuel supply means 15 are provided with the cutout 17a, the discharge passage 24, and the communication pipe 29.
Is communicated via.

Therefore, the crank web 17 is substantially a rotary valve, and the discharge passage 24 is opened and closed by the crank web 17.

As shown in FIG. 1, the communication pipe 29 for communicating the discharge passage 24 with the fuel supply means 15 is provided with a bypass pipe 30 between the fuel supply means 15 and the engine side opening of the discharge passage 24. ing. The bypass pipe 30 has a structure in which the communication pipe 29 and the intake passage 23 in the engine body 20 communicate with each other via an opening / closing valve 31. Also,
The open / close valve 31 is configured to open when the load of the engine 1 is smaller than a predetermined value and close when the load is large.

In the engine 1 constructed as described above, when the crankshaft assembly is mounted on the engine body 20 and the crankshaft 2 is rotated, the piston 4 reciprocates in the cylinder hole 5 and the connecting rod 7 is connected. While swinging in the accommodating portion 22, it moves up and down to perform a pendulum motion. A rotation locus drawn by the center of the large end of the connecting rod 7 at this time is shown by a chain double-dashed line C in FIG.

When the piston 4 is located near the bottom dead center, the crankshaft 2 rotates clockwise as shown by the arrow in FIG. 1, whereby the volume of the air chamber B gradually decreases and the internal volume of the air chamber B decreases. Air is compressed. At this time, as shown in FIG. 1, when the notch 17a of the crank web 17 faces the opening 24a of the discharge passage 24, the compressed air in the air chamber B is pushed out into the discharge passage 24 and the air chamber B is discharged. The volume of A gradually increases, and fresh air is introduced into the interior of the A through the air suction pipe 26. Further, the air pressure-fed to the discharge passage 24 is mixed with the fuel by the fuel supply means 15, and the intake valve 12 is opened and at the same time the combustion chamber 9 is opened.
It is pushed inside.

That is, in the engine 1, the product type compression is constructed in which the connecting rod accommodating portion 22 is the compression chamber, the piston 4 and the connecting rod 7 are the movers, and the crank web 17 is substantially a rotary valve for preventing compressed air backflow. A compressor is formed and supercharging can be performed by this compressor.

Here, the operation of the supercharger configured as described above will be described in more detail with reference to FIGS. 8 to 15. 8 to 15 show a series of operations from the start of the compression stroke of the engine 1 to the end of the explosion stroke. The case where the load of the engine 1 is larger than a predetermined value and the opening / closing valve 31 is closed will be described.

First, from the state shown in FIG.
When is rotated clockwise, the air chamber B is narrowed and the air chamber A is expanded, as shown in FIG. At this time,
The sealing surfaces 7b and 7c at the large end and the small end of the connecting rod 7 are in sliding contact with the peripheral wall surface 28 of the engine body 20 and the peripheral wall surface 4b of the piston 4, respectively. Since the crank web 17 of the crankshaft 2, the sliding contact surface 27 of the engine body 20 and the sliding contact surface 4a of the piston 4 are in sliding contact with each other, the air chamber A and the air chamber B are not communicated with each other.

Further, as shown in FIG. 9, the crankshaft 2
When is rotated, the notch 17a formed in the crank web 17 comes to face the opening 24a of the discharge passage 24, and the air chamber B is communicated with the discharge passage 24 through the notch 17a. For this reason, the air of the portion compressed by narrowing the air chamber B is pressure-fed to the communication pipe 29 through the notch 17 a and the discharge passage 24. That is, the formation position of the notch 17a is set to a position corresponding to the opening 24a when the connecting rod 7 is at the end of the compression stroke.

On the other hand, since the volume of the air chamber A is increased by the moving amount of the connecting rod and the rising amount of the piston and the pressure is reduced, fresh air is sucked into the air chamber A from the air suction pipe 26 by the reduced pressure amount.

The volume of the air chamber B is gradually narrowed by the rotation of the crankshaft 2. As shown in FIG. 10, the sealing surface 7b on the outer peripheral surface of the connecting rod 7 has an opening 24a.
It becomes narrowest when it reaches the lower opening edge. That is,
Air is pumped to the communication pipe 29 until the state shown in FIG. 10 is reached. In the compression stroke, the intake valve 12 of the engine 1
Is closed, and since the on-off valve 31 is closed at this time, the air discharged from the air chamber B is
It is stored between 9 and the intake valve 12.

When the crankshaft 2 further rotates from the state of FIG. 10 and the sealing surface 7b is separated from the peripheral wall surface 28 as shown in FIG. 11, the notch 17 of the crank web 17 is formed.
The opening a is separated from the opening 24a, and the opening 24a is closed by the crank web 17. For this reason, the compressed air in the communication pipe 29 will not be connected to the connecting rod accommodating portion 22.
There is no reverse flow inside (to the air chamber A side).

On the other hand, the volume of the air chamber A continues to increase even after the air chamber B is narrowed to the maximum, and is increased until the state shown in FIG. 11 is reached. At this time, the volume corresponding to the piston rise amount is the main volume increase amount.

The crankshaft 2 further rotates from the state shown in FIG. 11, and the piston 4 reaches the top dead center as shown in FIG. 12, whereby the compression stroke of the engine 1 ends. The fuel supply means 15 injects fuel before the state shown in FIG. 12 is reached. When an ignition plug (not shown) ignites and an explosion occurs in the combustion chamber 9, the piston 4 descends and the crankshaft 2 rotates as shown in FIGS. 13 to 14.

Then, as shown in FIG. 14, the connecting rod 7
When the sealing surface 7b on the outer peripheral surface of the large end of the sliding contact comes into sliding contact with the peripheral wall surface 28, the inside of the connecting rod accommodating portion 22 is again A, B2.
It will be defined in the air chamber. That is, in the air chamber B,
Until then, the inhaled air will enter the connecting rod accommodating portion 22.

When the crankshaft 2 rotates from the state shown in FIG. 14, the volume of the air chamber B gradually decreases and the volume of the air chamber A gradually increases as shown in FIG. Is compressed and fresh air is sucked into the connecting rod accommodating chamber 22. When the crankshaft 2 further rotates from the state of FIG. 15, the state shown in FIG. 8 is obtained.

When the load of the engine 1 is smaller than a predetermined value, the open / close valve 31 is opened and the bypass pipe 30 is opened.
The communication pipe 29 and the suction passage 23 are communicated with each other via the. In this state, the compressed air pushed out to the discharge passage 24 can be returned to the suction passage 23, so that the supercharging work at the time of low load is reduced. That is, when the load is low, the resistance at the time of supercharging becomes small, and the fuel consumption can be improved.

In the supercharging device constructed as described above,
Each time the crankshaft 2 makes one revolution, the volume of air obtained by adding the volume of the space in the connecting rod accommodating portion 22 and the stroke volume of the piston is pumped and stored in the communication pipe 29. When the intake valve 12 is opened during the intake stroke of the engine 1, twice as much compressed air as the crankshaft rotates once is supplied into the combustion chamber 9.

In this embodiment, the seal surface 7a is formed on the entire surface of the connecting rod 7 in the crankshaft direction, but the structure of the seal surface 7a can be appropriately changed as long as the same function can be achieved. Further, the sliding contact portions of the crank web 17, the connecting rod 7, the piston 4, and the engine body 20 of the crankshaft 2 are adopted in the rotor of the roots-type supercharging device in order to reduce friction resistance and increase airtightness. It is also possible to coat with a fluororesin.

Further, in the present embodiment, an example in which the discharge passage 24 is opened as the opening 24a at a position facing the outer peripheral surface of the crank web 17 has been described. The opening position of the opening 24a is the axis of the crank web 17. It can also be positioned at a portion facing the end face in the direction. Even in this case, the same effect as that of the above embodiment can be obtained.

Further, although the engine 1 in which the cylinder axis is directed in the vertical direction is used in the present embodiment, an engine to which the present invention is applied may be one in which the cylinder axis is directed in the horizontal direction. For example, it is possible to use an engine in which the surface of the paper of FIG. 1 is rotated clockwise by 90 degrees to make the cylinder axis line horizontal. In such an engine, the air chamber B is located above the air chamber A.
Then, a mist-like lubricating oil drifting in the crankcase 3 (this lubricating oil is the one directly supplied to the cylinder or the crankpin 18 portion) is accumulated in the air chamber B,
This lubricating oil will flow to the piston pin 19 side along the side surface 7d of the connecting rod 7. That is, it is possible to improve durability by supplying oil to the piston pin 19 that is difficult to lubricate.

Furthermore, in the present embodiment, the example in which the present invention is applied to the 4-cycle engine 1 is shown, but the present invention can also be applied to a 2-cycle engine. As a configuration for doing so, the discharge passage 24 is in direct communication with the scavenging passage. In this case as well, the primary compression ratio can be made larger than that of a normal two-cycle engine,
As the supercharger, the same effect as that of the above-described embodiment can be obtained. Further, the reed valve on the upstream side of the crank chamber is also unnecessary.

In addition, although the structure of the crank having a normal shape is shown in this embodiment, the journal portion 2 on only one side is provided.
a, a cantilevered crank formed by the crank web 17 and the crank pin 18 on only one side can also be used.

[0050]

As described above, in the engine turbocharger according to the present invention, the crankcase is formed with the inner peripheral wall on which the connecting rod is slidably contacted, and the inside of the crankcase is moved by the connecting rod at the crank angle except near the top dead center. The structure is divided into two air chambers, and one of these air chambers communicates with the fresh air introduction section, and the other air chamber communicates with the combustion chamber through the intake passage, and communicates with this combustion chamber. A positive displacement air compressor is used as a compression chamber and a connecting rod is used as a mover, and the upstream end of the intake passage is opened at a position facing the crank web to be closed by the crank web. When the connecting rod in the outer peripheral portion of the crank web is at the end of the compression stroke, a cutout that connects the compression chamber and the intake passage is formed in a portion corresponding to the opening. , It means that the crankshaft is only fresh air volume fraction of the stroke volume of the piston and the connecting rod accommodating portion per rotation is pumped into the combustion chamber, it is possible to increase the primary compression ratio.

Therefore, the primary compression ratio can be increased in performing the crankcase supercharging, so that the supercharging performance can be improved.

Further, since the supercharger according to the present invention can be formed only by the members constituting the engine, the structure is simplified and the number of parts is reduced as compared with the conventional supercharger. In particular, since the crank web substantially serves as a compressed air backflow prevention rotary valve, it is not necessary to separately provide a check valve in the intake system. Therefore, the intake resistance can be reduced and the structure can be simplified as compared with the conventional basic crankcase supercharging device.

Therefore, a small-sized supercharger capable of obtaining high output can be obtained at low cost.

Further, in the supercharging device according to the present invention, the discharge amount is determined by the width of the connecting rod and the bore and stroke of the engine, so that the degree of freedom in designing the discharge amount is high.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a 4-cycle engine provided with a supercharging device according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a perspective view showing a schematic configuration of a crankshaft used in the supercharging device according to the present invention.

FIG. 4 is a perspective view showing a schematic configuration of a connecting rod used in the supercharging device according to the present invention.

FIG. 5 is a perspective view showing a schematic configuration of a piston used in the supercharging device according to the present invention.

6 is a perspective view showing a schematic configuration of an engine body used in the supercharger according to the present invention, which shows a state in which the engine body is broken along line VI-VI in FIG.

FIG. 7 is a perspective view showing a schematic configuration of a supercharging device according to the present invention.

FIG. 8 is a cross-sectional view of the main parts in a state where the crankshaft is at bottom dead center.

FIG. 9 is a cross-sectional view of an essential part in a state where the crankshaft is rotated about 45 degrees from the bottom dead center.

FIG. 10 is a cross-sectional view of an essential part in a state in which the crankshaft rotates 90 degrees from the bottom dead center.

FIG. 11 is a cross-sectional view of an essential part in a state in which the crankshaft is rotated about 135 degrees from the bottom dead center.

FIG. 12 is a cross-sectional view of an essential part in a state in which the crankshaft rotates 180 degrees from the bottom dead center.

FIG. 13 is a cross-sectional view of an essential part in a state where the crankshaft is rotated about 225 degrees from the bottom dead center.

FIG. 14 is a cross-sectional view of an essential part in a state in which the crankshaft rotates 270 degrees from the bottom dead center.

FIG. 15 is a cross-sectional view of a main part in a state in which the crankshaft is rotated about 315 degrees from the bottom dead center.

[Explanation of symbols]

 1 4-cycle engine 2 crankshaft 3 crankcase 6 cylinder block 7 connecting rod 7a sealing surface 7b sealing surface 7c sealing surface 9 combustion chamber 17 crank web 17a notch 20 engine body 23 intake passage 24 discharge passage 24a opening 27 sliding surface 28 circumference Wall

Claims (1)

[Claims] 1. A crankcase is formed with an inner peripheral wall on which a connecting rod is slidably contacted, and the inside of the crankcase is partitioned into two air chambers by the connecting rod at a crank angle except near the top dead center. One of these air chambers is formed. Volume of the air chamber communicated with the combustion chamber through the intake passage and the air chamber communicated with the combustion chamber as the compression chamber and the connecting rod as the mover. Type compressor, which has a structure in which the upstream end of the intake passage is opened at a position facing the crank web and is closed by the crank web. When the connecting rod at the outer peripheral portion of the crank web is at the end of the compression stroke, A supercharging device for an engine, characterized in that a notch that connects the compression chamber and the intake passage is formed in a portion corresponding to the opening.