JP2013130135A - Four-cycle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a four-cyclk engine capable of miniaturizing a cylinder head and preventing gas from leaking.SOLUTION: Cylinder sleeves 7 coupling cylindr bore walls 8 and ceiling walls 10 of combustion chambers 9 are rotatably arranged in an engine body 1, air suction openings 24 and air discharging openings 25 are opened in outside ceiling walls 29 formed in the engine body so as to extend along outside faces of the ceiling walls 10, air suction opening seals 31 and air discharging opening seals 32 are arranged between the ceiling walls 10 and the outside ceiling walls 29, the cylinder sleeves 7 are rotated by one rotation while a crank shaft 6 is rotated by two rotations by driving side bevel gears 26 of the crank shaft 6 and driven side bevel gears 27 of the cylinder sleeve 7 sides, communication holes 13 of the ceiling walls 10 are connected to the air suction openings 24 and the air discharging openings 25, the cylinder sleeves 7 are movable in the axial line direction of the cylinder bores, coil springs 28 pushing the ceiling walls 10 to the outside ceiling walls 29 are arranged between the cylinder sleeves 7 and the driven side bevel gears 27.

Description

  The present invention relates to a four-cycle engine used for vehicles and the like, and more particularly to a four-cycle engine that performs intake and exhaust without using a stem-type valve having a valve stem.

  In a four-cycle engine, if intake and exhaust can be performed without using a stem type valve, a valve mechanism for driving the stem type valve, such as a camshaft, can be omitted, and the configuration around the cylinder head can be omitted. It can be simplified. An example of such a 4-cycle engine is described in Patent Document 1 below. In the 4-cycle engine described in Patent Document 1, the cylinder has a double structure, the inner sleeve constituting the cylinder bore is rotatable with respect to the outer cylinder, and the inner sleeve is connected to the crankshaft by a bevel gear attached to the crankshaft. Rotate at half the rotational speed. A communication passage is formed in a cylindrical portion integral with the inner sleeve above the combustion chamber of the inner sleeve, and this communication passage connects the intake port and the exhaust port to the combustion chamber at a predetermined timing as the inner sleeve rotates. Then, intake and exhaust are performed.

  However, in the four-cycle engine described in the cited document 1, since the cylindrical portion is provided above the combustion chamber, downsizing of the cylinder head is limited. On the other hand, in the 4-cycle engine described in Patent Document 2 below, an intake port and an exhaust port are formed in the ceiling wall of the combustion chamber, and a rotary disk is interposed between the ceiling wall and the intake port and the exhaust port. A communication hole is formed in the rotary disk, and the rotary disk is rotated by a gear, a chain, or a belt at a half speed of the crankshaft. The communication hole provided in the rotating disk continues the intake port and the intake port at a predetermined timing, and continues the exhaust port and the exhaust port at a predetermined timing to perform intake and exhaust. In the four-cycle engine described in Patent Document 2, since a so-called rotary valve interposed above the combustion chamber is a rotary disk, the cylinder head can be further reduced in size.

JP 2005-515357 A JP 2001-182512 A

However, in the engine of Patent Document 2, there is no seal structure between the intake and exhaust ports and the rotary disk, or between the rotary disk and the intake and exhaust ports, and the intake and exhaust ports and the rotary type are not provided. Since there is no structure for pressing the disc or the rotating disc and the intake port and the exhaust port, there is a possibility that gas leaks from the gap between the intake port and the exhaust port and the rotary disc or between the rotary disc and the intake port and the exhaust port. .
The present invention has been made paying attention to the above-described problems, and an object of the present invention is to provide a four-cycle engine in which a cylinder head can be miniaturized and gas leakage does not occur.

  In order to solve the above-described problems, an embodiment of the present invention provides a four-cycle engine that performs intake and exhaust by a rotating body that rotates around the axis of a cylinder bore in synchronization with a crankshaft, and is capable of rotating around the axis of the cylinder bore. A cylinder sleeve integrally connected with a cylinder bore wall and a spherical ceiling wall of a combustion chamber, a spherical outer ceiling wall formed on the engine body and along an outer surface of the ceiling wall of the cylinder sleeve, An intake port that is opened in the outer ceiling wall and is located at the downstream end of the intake port and an exhaust port that is located at the upstream end of the exhaust port, and communication that is formed in the cylinder sleeve and communicates the intake and exhaust ports to the combustion chamber A seal member disposed between the ceiling wall and the outer ceiling wall to prevent gas leakage from the communication hole and the intake and exhaust ports; The cylinder sleeve is connected so as to be movable in the axial direction of the cylinder bore, and the cylinder sleeve is rotated once while the crankshaft rotates twice, and the communication hole is continuously connected to the intake port and the exhaust port at a predetermined timing. A four-cycle engine comprising: a mechanism; and a pressing member that is disposed between the cylinder sleeve and the driving mechanism and moves the cylinder sleeve in a direction of pressing the ceiling wall against the outer ceiling wall.

  The drive mechanism includes a drive-side bevel gear disposed on the crankshaft side and a driven-side bevel gear that meshes with the drive-side bevel gear and is coupled to the cylinder sleeve, and the pressing member is connected to the driven member. The four-cycle engine is arranged between the drive-side bevel gear and the cylinder sleeve.

In the four-cycle engine, the pressing member is a coil spring.
The engine body is a four-cycle engine characterized in that the outer ceiling wall and the cylinder bore wall are cooled by engine oil.

  Thus, according to an embodiment of the invention, when intake and exhaust are performed by a rotating body that rotates around the axis of the cylinder bore in synchronization with the crankshaft, the cylinder bore wall and the spherical ceiling wall of the combustion chamber are integrated. The connected cylinder sleeve is arranged on the engine body so as to be rotatable about the axis of the cylinder bore, and a spherical outer ceiling wall is formed on the engine body along the outer surface of the cylinder sleeve ceiling wall, which is located at the downstream end of the intake port. An exhaust port located at the upstream end of the intake port and the exhaust port is opened in the outer ceiling wall, and a communication hole is formed in the ceiling wall of the cylinder sleeve to connect the intake port and the exhaust port to the combustion chamber. Place a sealing member between the ceiling wall and the outer ceiling wall to prevent gas leakage from the outlet and exhaust port, and rotate the cylinder sleeve once to make the communication hole while the crankshaft rotates twice. The cylinder sleeve is connected to a drive mechanism that is connected to the intake port and the exhaust port at the timing of the cylinder sleeve so as to be movable in the axial direction of the cylinder bore. And the drive mechanism. Thus, gas leakage from between the ceiling wall of the cylinder sleeve and the outer ceiling wall of the engine body can be prevented to improve the operability of the engine, and the cylinder head can be miniaturized.

  The driving bevel gear disposed on the crankshaft side and the driven bevel gear meshing with the driving bevel gear and coupled to the cylinder sleeve constitute a driving mechanism, and the pressing member is disposed between the driven bevel gear and the cylinder sleeve. Therefore, the driven bevel gear can be pressed against the driving bevel gear, the noise at the time of gear engagement due to backlash can be reduced, and the operability of the engine can be improved.

In addition, by configuring the pressing member with a coil spring, the pressing force for pressing the ceiling wall of the cylinder sleeve against the outer ceiling wall of the engine body or the pressing force for pressing the driven bevel gear against the driving bevel gear can be adjusted to an appropriate magnitude. And the drivability of the engine can be improved.
In addition, the engine body cools the outer ceiling wall and the cylinder bore wall with engine oil, so that the sealing structure of the cooling passage can be simplified even if the cylinder sleeve rotates with respect to the engine body.

1 is a perspective view showing an embodiment of a 4-cycle engine of the present invention. It is an internal structure figure of the 4-cycle engine of FIG. It is a longitudinal cross-sectional view of the 4-cycle engine of FIG. FIG. 2 is a detailed view of the cylinder sleeve of FIG. 1. FIG. 2 is a detailed view of the engine body of FIG. 1.

Next, an embodiment of a four-cycle engine of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing the external appearance of the four-cycle engine of the present embodiment, FIG. 2 is an internal structure diagram of the four-cycle engine of FIG. 1, and FIG. 3 is a longitudinal sectional view of the four-cycle engine of FIG. 4 is a detailed view of the cylinder sleeve of FIG. 1, FIG. 4a is a plan view, FIG. 4b is a front view, and FIG. 4c is a longitudinal sectional view. 5 is a detailed view of the engine body of FIG. 1, FIG. 5a is a front view, FIG. 5b is a bottom view, and FIG. 5c is a longitudinal sectional view. The four-cycle engine of the present embodiment is a parallel two-cylinder engine mounted on a vehicle such as a motorcycle or a four-wheeled vehicle or a device such as a generator, and may be mounted in various directions. The upper part of FIG. 1 is defined as the upper part of the engine.

  The four-cycle engine of the present embodiment performs intake and exhaust by a rotating body that rotates around the axis of the cylinder bore in synchronization with the crankshaft. A cylinder head 2 and a cylinder 3 that are generally called are integrated. The engine body 1 is provided. Two engine bodies 1 for constituting a two-cylinder engine are mounted above an upper crankcase (the upper half of the crankcase) 4, and below the upper crankcase 4 are a lower crankcase (the lower half of the crankcase) 5. The crankshaft 6 is disposed between the upper crankcase 4 and the lower crankcase 5. Reference numeral 21 in the figure denotes a spark plug hole in which a spark plug (not shown) is mounted, and penetrates from the engine body 1 to a cylinder sleeve 7 described later.

  In the present embodiment, the cylinder 3 of the engine body 1 has a double structure, and the cylinder bore wall 8 is substantially constituted by a cylinder sleeve 7 separate from the engine body 1. A ceiling wall 10 of the combustion chamber 9 is integrally formed above the cylinder bore wall 8 of the cylinder sleeve 7, and the combustion chamber 9 (cylinder bore) is disposed downstream of the intake port 11 on the ceiling wall 10 as will be described in detail later. A communication hole 13 is formed to continue to the intake port 24 located at the end or the exhaust port 25 located at the upstream end of the exhaust port 12. The ceiling wall 10 has a spherical shape.

  The engine body 1 has a spherical outer ceiling wall 29 formed along the ceiling wall 10 of the combustion chamber 9 of the cylinder sleeve 7, and is located at the downstream end of the intake port 11 in the outer ceiling wall 29. An exhaust port 25 located at the upstream end of the intake port 24 and the exhaust port 12 is opened. Further, the cylinder sleeve 7 is supported in the cylinder 3 of the engine body 1 via a bearing 14 so as to be rotatable around the axis of the cylinder bore. A seal ring 16 is disposed between the cylinder sleeve 7 and the engine body 1 on the side of the combustion chamber 9.

  Reference numeral 22 in the figure denotes an empty head cooling jacket formed in the cylinder head 2 of the engine body 1, and reference numeral 23 denotes an empty state formed between the cylinder sleeve 7 and the cylinder 3 of the engine body 1. The engine oil cooled by an oil cooler (not shown) is supplied to cool the cylinder head 2, the cylinder 3, and the cylinder sleeve 7, that is, the outer ceiling wall 29 and the cylinder bore wall 8. The head cooling jacket 22 and the cylinder cooling jacket 23 are connected by a cooling communication path 30.

  A piston 15 is accommodated in the cylinder bore of each cylinder sleeve 7. The piston 15 is connected to the crankpin 17 of the crankshaft 6 by a connecting rod (connecting rod) 18. The crankshaft 6 has a crank journal 19 rotatably supported by the upper crankcase 4 and the lower crankcase 5 via a bearing metal 20. As is well known, when the piston 15 reciprocates in the cylinder bore as the air-fuel mixture in the combustion chamber 10 burns and explodes, the reciprocating motion is extracted as the rotational motion of the crankshaft 6.

  In the present embodiment, as described above, the communication hole 13 formed in the ceiling wall 10 of the cylinder sleeve 7 continuously connects the combustion chamber 9 and the intake port 24 (see FIG. 5) located at the downstream end of the intake port 11. Or the exhaust port 25 (see FIG. 5) located at the upstream end of the combustion chamber 9 and the exhaust port 12 is connected to the cylinder sleeve 7 at a rotational speed ½ that of the crankshaft 6. There is. Therefore, in this embodiment, the drive side bevel gear 26 is attached to both ends of the crankshaft 6. On the other hand, a cylindrical skirt portion 7a having a larger diameter than the cylinder bore is integrally formed at the lower end portion of the cylinder sleeve 7, and a driven side bevel gear 27 that meshes with the driving side bevel gear 26 on the outer periphery of the lower end portion of the skirt portion 7a. And the driven side bevel gear 27 and the driving side bevel gear 26 are engaged with each other. The gear ratio between the driven side bevel gear 27 and the driving side bevel gear 26 is 2.

  In the present embodiment, the tooth traces form a spline or serration in the vertical direction, that is, the axial direction of the cylinder bore, on the outer periphery of the lower end of the skirt portion 7a, and the spline that meshes with the inner periphery of the driven bevel gear 27 Alternatively, the driven side bevel gear 27 is movable in the vertical direction, that is, the axial direction of the cylinder bore by forming serrations and engaging the two. A coil spring 28 as a pressing member is interposed between the upper end portion of the driven side bevel gear 27 and the flange portion 7b formed at the upper end portion of the skirt portion 7a. Accordingly, the cylinder sleeve 7 is moved so that the ceiling wall 10 of the combustion chamber 9 is pressed against the outer ceiling wall 29 of the engine body 1, and at the same time, the driven side bevel gear 27 is pressed against the driving side bevel gear 26.

  FIG. 5 b shows details of the intake port 24 and the exhaust port 25. Note that one communication hole 13 provided in the ceiling wall 10 rotates around the cylinder bore axis and is located at the intake port 24 located at the downstream end of the combustion chamber 9 and the intake port 11 or at the upstream end of the exhaust port 12. In order to open and close the exhaust port 25 at an appropriate timing, for example, the intake port 24 and the exhaust port 25 are arranged in a region where the relative angle about the cylinder bore axis is approximately 270 degrees away along the rotation direction of the communication hole 13. There is a need to.

  In the present embodiment, an intake port seal (seal member) 31 is attached to the end surface of the intake port 24 on the cylinder sleeve 7 side, that is, the end surface facing the ceiling wall 10 of the combustion chamber 9, and the cylinder sleeve 7 of the exhaust port 25. An exhaust port seal (seal member) 32 is attached to the side end surface, that is, the end surface facing the ceiling wall 10 of the combustion chamber 9. The intake port seal 31 and the exhaust port seal 32 are made of, for example, a relatively hard thin ring-shaped metal plate and have a larger diameter than the communication hole 13 formed in the ceiling wall 10 of the cylinder sleeve 7. The intake port seal 31 and the exhaust port seal 32 perform so-called sliding contact with the ceiling wall 10 of the cylinder sleeve 7 to ensure sufficient adhesion. In the present embodiment, since the ceiling wall 10 of the cylinder sleeve 7 is pressed against the outer ceiling wall 29 by the coil spring 10, the intake port seal 31 and the exhaust port seal 32 are always in close contact with the ceiling wall 10 of the cylinder sleeve 7, Even if the communication hole 13 continues the intake port 24 or the exhaust port 25 to the combustion chamber 9, no gas leakage occurs.

  As described above, in the four-cycle engine of the present embodiment, when intake and exhaust are performed by the rotating body that rotates around the axis of the cylinder bore in synchronization with the crankshaft, the cylinder bore wall 8 and the spherical ceiling wall 10 of the combustion chamber 9 Are connected to the engine body 1 so as to be rotatable around the axis of the cylinder bore, and a spherical outer ceiling wall 29 is formed on the engine body 1 along the outer surface of the ceiling wall 10 of the cylinder sleeve 7. The intake port 24 positioned at the downstream end of the intake port 11 and the exhaust port 25 positioned at the upstream end of the exhaust port 12 are opened in the outer ceiling wall 29, and the intake port 24 and the exhaust port 25 communicate with the combustion chamber 9. The communication hole 24 is formed in the ceiling wall 10 of the cylinder sleeve 7 to prevent gas leakage from the communication hole 13, the intake port 24, and the exhaust port 25. An inlet seal 32 (seal member) is disposed between the ceiling wall 10 and the outer ceiling wall 29, and the cylinder sleeve 7 is rotated once while the crankshaft 6 rotates twice, so that the communication hole 13 is opened at a predetermined timing. 24 and the exhaust mechanism 25 are connected to the cylinder sleeve 7 so as to be movable in the axial direction of the cylinder bore, and the coil spring (pressing force) moves the cylinder sleeve 7 in the direction in which the ceiling wall 10 is pressed against the outer ceiling wall 29. Member) 28 is disposed between the cylinder sleeve 7 and the drive mechanism. As a result, gas leakage from between the ceiling wall 10 of the cylinder sleeve 7 and the outer ceiling wall 29 of the engine body 1 can be prevented to improve engine operability, and the cylinder head can be miniaturized. Become.

  A driving mechanism is constituted by a driving side bevel gear 26 arranged on the crankshaft 6 side and a driven side bevel gear 27 meshed with the driving side bevel gear 26 and connected to the cylinder sleeve 7, and a coil spring (pressing member) 28 is provided. By arranging the driven bevel gear 27 between the driven bevel gear 27 and the cylinder sleeve 7, the driven bevel gear 27 can be pressed against the drive bevel gear 26, noise during gear engagement due to backlash can be reduced, and engine operability can be improved. Can be improved.

Further, since the pressing member is constituted by the coil spring 28, the pressing force for pressing the ceiling wall 10 of the cylinder sleeve 7 against the outer ceiling wall 29 of the engine body 1 or the pressing force for pressing the driven bevel gear 27 against the driving bevel gear 26 is appropriate. It becomes easy to adjust to a large size, and the operability of the engine can be improved.
Further, the engine body 1 cools the outer ceiling wall 29 and the cylinder bore wall 8 with engine oil, so that the sealing structure of the cooling passage can be simplified even if the cylinder sleeve 7 rotates with respect to the engine body 1. .

  In addition, the arrangement position of the sealing member for preventing gas leakage from the communication hole 13 and the intake port 24 and the exhaust port 25 is not limited to the intake port 24 and the exhaust port 25, and may be disposed on the communication hole 13 side, for example. You may arrange | position in both the communicating hole 13, the inlet port 24, and the exhaust port 25. FIG. In short, the sealing member for preventing gas leakage from the communication hole 13, the intake port 24 and the exhaust port 25 may be disposed between the ceiling wall 10 and the outer ceiling wall 29.

  Further, the form of the engine body 1 is not limited to the above, and a structure in which a plurality of cylinders and an upper crankcase are integrated, such as a general engine block, can be similarly applied.

1 is the engine body 2 is the cylinder head 3 is the cylinder 4 is the upper crankcase (the upper half of the crankcase)
5 is the lower crankcase (lower half of the crankcase)
6 is a crankshaft 7 is a cylinder sleeve 8 is a cylinder bore wall 9 is a combustion chamber 10 is a ceiling wall 11 is an intake port 12 is an exhaust port 13 is a communication hole 14 is a bearing 15 is a piston 16 is a seal ring 17 is a crankpin 18 is a connecting rod (Connecting rod)
19 is a crank journal 20 is a bearing metal 21 is a spark plug hole 22 is a head cooling jacket 23 is a cylinder cooling jacket 24 is an intake port 25 is an exhaust port 26 is a driving side bevel gear 27 is a driven side bevel gear 28 is a coil spring 29 is an outer ceiling Wall 30 is a cooling communication path 31 is an inlet seal 32 is an exhaust seal

Claims (4)

In a 4-cycle engine that performs intake and exhaust by a rotating body that rotates around the axis of a cylinder bore in synchronization with the crankshaft,
A cylinder sleeve which is disposed in the engine body so as to be rotatable around the axis of the cylinder bore and integrally connects the cylinder bore wall and the spherical ceiling wall of the combustion chamber;
A spherical outer ceiling wall that is formed in the engine body and extends along an outer surface of the ceiling wall of the cylinder sleeve;
An intake port that is opened in the outer ceiling wall and is located at the downstream end of the intake port; and an exhaust port that is located at the upstream end of the exhaust port;
A communication hole formed in the cylinder sleeve and communicating the intake port and the exhaust port to a combustion chamber;
A seal member disposed between the ceiling wall and the outer ceiling wall to prevent gas leakage from the communication hole, the intake port, and the exhaust port;
The cylinder sleeve is connected so as to be movable in the axial direction of the cylinder bore, and the cylinder sleeve is rotated once while the crankshaft rotates twice, and the communication hole is continuously connected to the intake port and the exhaust port at a predetermined timing. Mechanism,
A four-cycle engine comprising: a pressing member that is disposed between the cylinder sleeve and the drive mechanism and moves the cylinder sleeve in a direction in which the ceiling wall is pressed against the outer ceiling wall. The drive mechanism is
A drive-side bevel gear disposed on the crankshaft side;
A driven side bevel gear meshing with the driving side bevel gear and coupled to the cylinder sleeve;
The four-stroke engine according to claim 1, wherein the pressing member is disposed between the driven side bevel gear and a cylinder sleeve.   The four-stroke engine according to claim 2, wherein the pressing member is a coil spring.   The four-stroke engine according to any one of claims 1 to 3, wherein the engine body cools the outer ceiling wall and the cylinder bore wall with engine oil.

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