JP2021055649A - Internal combustion engine - Google Patents

Abstract

To make dynamic characteristics of a power transmission path from an eccentric shaft to an air intake/exhaust mechanism through a drive mechanism as uniform as possible, between the plurality of air intake/exhaust mechanisms.SOLUTION: An air intake/exhaust mechanism B is equipped with rotary valves 20 and 21. A drive mechanism C driving the air intake/exhaust mechanism is composed of a drive gear 24 that is coaxially adhered to an output shaft 2b, first idle gears 25 that are engaged with the drive gear, second idle gears 26 that are coaxially and integrally attached to the first idle gears and have rotary surfaces at positions separated from a rotary surface of the drive gear, driven gears 27 and 28 that are integrally attached to the rotary valves, and an endless band 29 that is wound between each second idle gear and the driven gear attached to the rotary valve of each air intake/exhaust mechanism.SELECTED DRAWING: Figure 2

Description

The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine provided with an air supply / exhaust mechanism using a tappet valve.

Generally, an internal combustion engine is provided with an air supply / exhaust mechanism for supplying an air mixture of fuel and exhausting a combustion gas.

As shown in Patent Document 1, the applicant applies to a crankcase in which an eccentric shaft is provided in which the axis of the input shaft and the axis of the output shaft are eccentrically provided, and the crankcase is orthogonal to the axis of the output shaft and The four cylinder blocks mounted on the crankcase and the four cylinder blocks mounted on the crankcase so that the cylinders are radially formed around the output shaft at intervals of 90 degrees and the cylinders on both sides of the output shaft are coaxial. A cylinder head mounted on each of these cylinder blocks to form a combustion chamber, a piston slidably installed in each of the cylinder blocks, a connecting rod connecting these pistons and the input shaft, and the like. An air supply / exhaust mechanism mounted on the cylinder block for supplying / exhausting air to / from the combustion chamber and a drive mechanism for driving the air supply / exhaust mechanism are provided. We have proposed an internal combustion engine that is provided with a connecting rod that supports it so that it can swivel around it, and a piston built in a coaxial cylinder that sandwiches the output shaft at both ends.

This internal combustion engine uses an eccentric shaft in which the axis of the input shaft and the axis of the output shaft are eccentrically provided. By connecting to the input shaft via a connecting portion that supports the swivel and arranging the connecting rods connected to each input shaft at right angles, vibration of the output shaft at the time of input from the piston can be suppressed. The cooperation is suppressed to realize smooth rotation of the output shaft.

Patent No. 6366959

By the way, in the internal combustion engine in the above-mentioned proposal, since the four cylinder blocks and the cylinder heads are arranged on substantially the same plane, each supply / exhaust mechanism incorporated in these cylinder heads is also included. They are arranged on substantially the same plane.

Then, between each air supply / exhaust mechanism and the eccentric shaft, a drive mechanism that transmits the rotation of the eccentric shaft to each air supply / exhaust mechanism and drives these air supply / exhaust mechanisms is interposed.

Since these drive mechanisms must connect the eccentric shaft and each air supply / exhaust mechanism on a one-to-one basis, they are installed at intervals in the axial direction of the eccentric shaft.

If each drive mechanism is installed at intervals in the axial direction of the eccentric shaft, it is necessary to lengthen the eccentric shaft accordingly, and the connection position between each drive mechanism and each air supply / exhaust mechanism is also the axis of the eccentric shaft. It shifts in the direction.

Along with this, a structural difference occurs between the air supply / exhaust mechanisms, and a difference occurs in the mass of the moving part, the rotational resistance, and the like.
It is assumed that such a difference in the dynamic characteristics of the air supply / exhaust mechanism affects the rotation of the eccentric shaft and impairs the smoothness of the rotation.

In view of the problems assumed in the above proposal, the present invention makes the dynamic characteristics of the power transmission path from the eccentric shaft through the drive mechanism to the air supply / exhaust mechanism as uniform as possible among the plurality of air supply / exhaust mechanisms. This is an issue that needs to be resolved.

In the internal combustion engine of the present invention, in order to solve the above-mentioned problems, a crankcase in which an eccentric shaft provided with an eccentric axis of an input shaft and an axis of an output shaft is provided is orthogonal to the axis of the output shaft. In addition, four cylinders mounted on the crankcase so that the cylinders are radially formed around the output shaft at intervals of 90 degrees and the cylinders on both sides of the output shaft are coaxial. A block, a cylinder head attached to each of these cylinder blocks to form a combustion chamber, a piston slidably installed in each cylinder block, and a connecting rod connecting these pistons and the input shaft. A rod, an air supply / exhaust mechanism mounted on the cylinder block to supply / exhaust air to the combustion chamber, and a drive mechanism for driving the air supply / exhaust mechanism are provided, and the input shaft is output to the intermediate portion of the connecting rod. In an internal combustion engine in which a connecting rod that rotatably supports around the axis of the shaft is provided, and a piston built in a coaxial cylinder sandwiching the output shaft is connected to both ends.
The air supply / exhaust mechanism includes a rotary valve, and the drive mechanism is provided corresponding to a drive gear coaxially fixed to the output shaft and the air supply / exhaust mechanism, and is meshed with the drive gear. The first idle gear and the second idle gear that are coaxially attached to these first idle gears and have a rotating surface at a position separated from the rotating surface of the drive gear are integrally attached to the rotary valve. It is characterized in that it is composed of a driven gear and an endless band wound between each of the second idle gears and a driven gear attached to a rotary valve of each of the supply / exhaust mechanisms.

With such a configuration, the connecting portion between each drive mechanism and the eccentric shaft is coaxially and integrally attached to the first idle gear that meshes with the drive gear of the output shaft and the first idle gear. The idle gear is separated from the drive gear in the radial direction of the eccentric shaft and is separated from the drive gear in the axial direction of the eccentric shaft.

Although the second idling gears are positioned on the same plane, they are separated from each other with an eccentric shaft in between.

Further, each endless band wound around these second idling gears is also positioned on the same surface, and accordingly, the driven gear of the air supply / exhaust mechanism around which these endless bands are wound is also positioned on the same surface. Be made to.
As a result, each drive mechanism is arranged on the same surface.

By arranging each drive mechanism on the same surface in this way, it is possible to make the structure and shape of each air supply / exhaust mechanism uniform, and these dynamic characteristics are made uniform, so that the rotation of the eccentric shaft can be made uniform. The effect is reduced and the smoothness of its rotation is ensured.

Further, the positional relationship between each drive mechanism and the drive gear of the eccentric shaft is suppressed to a deviation corresponding to the distance between the first idling gear and the second idling gear, whereby the lengthening of the eccentric shaft is suppressed.

A toothed belt or a chain belt is preferably used as the endless band.

According to the present invention, the dynamic characteristics of the power transmission path from the eccentric shaft to the air supply / exhaust mechanism via the drive mechanism can be made uniform among a plurality of air supply / exhaust mechanisms as much as possible, and the output from the eccentric shaft can be stabilized. it can.

It is a vertical sectional view which shows one Embodiment of this invention. It is an exploded perspective view of the internal mechanism which shows one Embodiment of this invention. An embodiment of the present invention is shown, and is a diagram showing a state in which a cylinder block and a cylinder head are cut along line III of FIG. It is a front view which shows one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 1 indicates an internal combustion engine according to the present embodiment.

The internal combustion engine 1 is orthogonal to the crankcase 3 in which the eccentric shaft 2 provided with the axis L1 of the input shaft 2a and the axis L2 of the output shaft 2b eccentrically provided, and the axis L2 of the output shaft 2b. , The cylinders 4a are formed radially around the output shaft 2b at intervals of 90 degrees, and further, the cylinders 4a on both sides of the output shaft 2b are mounted on the crankcase 3 so as to be coaxial. A number of cylinder blocks 4, a cylinder head 5 attached to each of the cylinder blocks 4 to form a combustion chamber A, a piston 6 slidably installed in each of the cylinder blocks 4, and these pistons. A connecting rod 7 that connects the input shaft 2a of No. 6, an air supply / exhaust mechanism B that is attached to the cylinder block 4 to supply / exhaust air to the combustion chamber A, and a drive mechanism C that drives the air supply / exhaust mechanism B. The connecting rod 7 is provided with a connecting portion Z that rotatably supports the input shaft 2a around the axis L2 of the output shaft 2b in the middle portion of the connecting rod 7, and is coaxial with both ends sandwiching the output shaft 2b. The piston 6 built in the cylinder 4a is connected.

The eccentric shaft 2, the piston 7, and the connecting rod 7 are configured as follows.
First, the output shaft 2b is divided into two in the length direction and connected to both ends of the input shaft 2a in a state where relative rotation is restricted, thereby forming the eccentric shaft 2.

That is, as shown in FIGS. 1 and 2, notch-shaped flat surfaces are formed on the side surfaces of the ends of the input shaft 2a and the output shaft 2b in an eccentric state, and these flat surfaces XY By fitting them in the locking holes 8a formed in the balance weight 8 in a state of being in close contact with each other, the input shaft 2a and both output shafts 2b are connected in a state where the relative rotation is restricted.

An eccentric cam 9 is rotatably fitted in the intermediate portion of the input shaft 2a in the length direction.

The eccentric cam 9 is formed with a fitting hole 9a into which the input shaft 2a is rotatably inserted, is spaced in the axial direction of the input 2a, and is predetermined in the radial direction of the fitting hole 9a. Cylindrical cams 9b and 9c are provided in a state where the distance is deviated.

Each of the cams 9b and 9c of the eccentric cam 9 is rotatably fitted to an intermediate portion of a connecting rod 7 having pistons 6 at both ends.

More specifically, a through hole 7a in which the bearing 10 is mounted is formed in the middle portion of the connecting rod 7, and the cams 9b and 9c are fitted into the bearing 10 mounted in the through hole 7a. As a result, the eccentric cam 9 is mounted on the input shaft 2a.

The two connecting rods 7 are arranged so as to be orthogonal to the input shaft 2a and orthogonal to each other.

Each cylinder head 5 is formed with an air supply passage 5a for supplying the combustion air-fuel mixture and an exhaust passage 5b for exhausting the combustion gas, and the air supply passage 5a and the exhaust passage 5b are opened and closed. The air supply / exhaust mechanism B for performing the above is provided.

The air supply / exhaust mechanism B is rotatably attached to the cylinder head 5, and is rotatably attached to the air supply rotary valve 20 that opens and closes the opening on the combustion chamber A side of the air supply passage 5a, and the cylinder head 5. It is composed of an exhaust rotary valve 21 that opens and closes the opening on the combustion chamber A side of the exhaust passage 5b.

On the other hand, both ends of the output shaft 2b are projected to the outside through the crankcase 3, one end is a power transmission part, and between the other end and the air supply / exhaust mechanism B, A drive mechanism C is provided that opens and closes the air supply rotary valve 20 and the exhaust rotary valve 21 in synchronization with the rotation of the eccentric shaft 2.

The drive mechanism C includes a drive gear 24 coaxially fixed to the output shaft 2b and a first idle gear 25 provided corresponding to each of the supply / exhaust mechanism B and meshed with the drive gear 24. , As shown in FIG. 1, a second idle gear 26 which is coaxially and integrally attached to these first idle gears 25 and has a rotating surface at a position separated from the rotating surface of the drive gear 24, and an air supply rotary valve. A toothed belt, a chain belt, etc. wound between the driven gears 27 and 28 integrally attached to the ends of the 20 and the exhaust rotary valve 21 and the second idle gear 26 and the driven gears 27 and 28. It is composed of an endless band 29 and.

Further, in the present embodiment, since the engine is a 4-cycle internal combustion engine, the same gears are used for the drive gear 24, the first idle gear 25, and the second idle gear 26, and the driven gears 27 and 28 for these gears are used. The gear ratio is doubled.

The second idle gear 26, the driven gears 27 and 28, and the endless band 29 constituting the drive mechanism C are positioned in the same plane plane orthogonal to the eccentric shaft 2 in the vicinity of the drive gear 24.

In FIG. 3, reference numeral 30 indicates a spark plug.

In the internal combustion engine 1 according to the present embodiment configured in this way, each drive mechanism C is arranged radially separated from the eccentric shaft 2 by the first idle gear 25, and mutual interference is avoided. ing.

Therefore, each of these drive mechanisms C can be arranged on the same surface, and the positional relationship with the air supply / exhaust mechanism B connected to them can be made uniform.

As a result, the structure and shape of each air supply / exhaust mechanism B can be made the same, and these dynamic characteristics can be made uniform to reduce the influence on the rotation of the eccentric shaft 2 and ensure the smoothness of the rotation. Can be done.

Further, the positional relationship between each drive mechanism C and the drive gear 24 provided on the eccentric shaft 2 is suppressed to a deviation corresponding to the distance between the first idling gear 25 and the second idling gear 26, whereby the eccentric shaft 2 It is possible to suppress the lengthening and suppress the weight increase.

1 Internal combustion engine 2 Eccentric shaft 2a Input shaft 2b Output shaft 3 Crank case 4 Cylinder block 4a Cylinder 5 Cylinder head 5a Air supply passage 5b Exhaust passage 6 Piston 7 Connecting rod 7a Through hole 8 Balance weight 8a Balance weight 9 Eccentric cam 9a Fitting Hole 9b Cam 9c Cam 10 Bearing 20 Air supply rotary valve 21 Exhaust rotary valve 24 Drive gear 25 1st idle gear 26 2nd idle gear 27 Driven gear 28 Driven gear 29 Endless band 30 Ignition plug A Combustion chamber B Supply / exhaust mechanism C Drive Mechanism X Flat part Y Flat part Z Connecting part

Claims (3)

A crankcase with an eccentric shaft in which the axis of the input shaft and the axis of the output shaft are eccentrically provided, and a cylinder that is orthogonal to the axis of the output shaft and radially at intervals of 90 degrees around the output shaft. The four cylinder blocks mounted on the crankcase and the combustion chambers mounted on each of these cylinder blocks are provided so that the cylinders on both sides of the output shaft are coaxial. A cylinder head to be formed, a piston slidably built in each cylinder block, a connecting rod connecting these pistons and the input shaft, and supply / exhaust to the combustion chamber mounted on the cylinder block. An air supply / exhaust mechanism for performing the above and a drive mechanism for driving the air supply / exhaust mechanism are provided, and a connecting portion for rotatably supporting the input shaft around the axis of the output shaft is provided in the middle portion of the connecting rod at both ends. In an internal combustion engine in which a piston built in a coaxial cylinder sandwiching the output shaft is connected to the portion.
The air supply / exhaust mechanism includes a rotary valve, and the drive mechanism is provided corresponding to a drive gear coaxially fixed to the output shaft and the air supply / exhaust mechanism, and is meshed with the drive gear. The first idle gear and the second idle gear that are coaxially attached to these first idle gears and have a rotating surface at a position separated from the rotating surface of the drive gear are integrally attached to the rotary valve. An internal combustion engine characterized by being composed of a driven gear and an endless band wound between each of the second idle gears and a driven gear attached to a rotary valve of each of the air supply / exhaust mechanisms. .. The internal combustion engine according to claim 1, wherein the endless band is a toothed belt. The internal combustion engine according to claim 1, wherein the endless band is a chain belt.

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