JPS63186914A - Exhaust timing controller for v-type two-cycle engine - Google Patents

Abstract

PURPOSE:To absorb the deflection dimension of a cylinder by constituting a valve body which controls the exhaust time by substantially moving the upper edge position of the exhaust port of each cylinder in the vertical direction, so as to be driven through an interlocking mechanism by the revolution of a common deriving shaft. CONSTITUTION:In a four-cylinder V-type two-cycle engine, the upper side cylinders S1 and S3 and front side cylinders S2 and S4 are arranged, keeping a prescribed interval H alternately towards a crankshaft. In the exhaust passage of each cylinder S1-S4, a plate-shaped valve body 20 for adjusting the exhaust timing according to the engine revolution speed is installed, and in each valve body 20, the exhaust timing is varied by substantially moving the upper edge position of the exhaust port of the cylinder in the vertical direction by the swing through a valve body supporting shaft 23. The valve body supporting shaft 23 of each cylinder,. S1-S4 is revolved through the interlocking mechanisms 31 and 32 by the revolution of a common driving shaft 30 installed in parallel to the crankshaft.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhaust timing control device for a V-type two-stroke engine.

[Prior Art] As an example of an exhaust timing control device for a multi-cylinder two-stroke engine, there is known one shown in Japanese Utility Model Publication No. 58-50 F32.

This device has a valve body (movable wall) placed above the exhaust passage of each cylinder, and a valve body support shaft for each cylinder parallel to the crankshaft. By swingably supporting each valve body by a shaft, and rotating the valve body support shaft to swing the valve body, the upper end position of the exhaust boat of each cylinder can be substantially adjusted by the swing end. It moves up and down to change the exhaust timing.

In this device, the support shafts of adjacent cylinders are engaged with each other, so that the valve bodies operate in conjunction with each other.

[Problems to be Solved by the Invention] By the way, the device shown in Publication No. 11r1 is applicable to an engine in which the cylinders are arranged in a row, This method cannot be applied to a type of roller in which the cylinder on the other side and the cylinder on the other side are arranged apart from each other by a predetermined included angle. Therefore, in the case of a V-type engine, the valve body support shafts separately disposed in one cylinder and the other cylinder must be connected via some kind of interlocking mechanism.

In that case, it is desirable that the parts arranged for each cylinder be as common as possible. However, in the case of a V-type engine, the cylinders on one side and the cylinders on the other side are not only separated, but also arranged alternately at regular intervals 1-I in the direction of the crankshaft.
There is a problem in that it is difficult to standardize parts.

SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust timing control device for a V-type two-stroke engine in which parts arranged for each cylinder can be made as common as possible.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention arranges the cylinders on one side and the cylinders on the other side at a predetermined included angle and at a constant interval 1 - in the direction of the crankshaft. A valve body is disposed in each of the exhaust passages of each cylinder of a V-type two-stroke engine arranged in a 6-6 arrangement, and a valve body support shaft is installed for each cylinder so that it is parallel to the crankshaft. These valve body supports t are movably supported by sleeves, respectively, and by rotating the valve body support shaft and swinging the valve body, each cylinder is moved by its swinging end. In the exhaust timing control device for a two-stroke engine, the exhaust timing is changed by substantially moving the upper end position of the exhaust boat up and down. and interlocking 4i3! on one end and the other end of this drive shaft, respectively. The proximal ends of the cylinders are connected, and the distal ends of these interlocking mechanisms are connected to the valve body support shaft of the cylinder on one side and the valve body support shaft of the cylinder on the other side, respectively.

[Effect: Each cylinder is spaced apart by a dimension C in the direction of the crankshaft. On the other hand, since the base end portions of the two interlocking mechanisms are respectively connected to one end side and the other end side of the drive shaft, they are deviated from each other by a certain dimension in the crankshaft direction. Therefore, by appropriately setting the length of the drive shaft and the dimensions of the interlocking mechanism, the displacement dimension of the cylinder can be absorbed, and the valve body support shaft on the cylinder side can be made into a common component.

[Example 1] An example of the present invention will be described below with reference to FIGS. 1 to 3.

Figure 1 shows the side of a motorcycle equipped with the engine of the example [? 7i and 2 are side views of a part of the engine in cross section, and FIG. 3 is a developed view of the drive system of the exhaust timing control device.

Reference numeral l in FIG. 1 indicates a vehicle body frame, and a V-type two-stroke engine E is suspended at the center of the lower part of the frame. Also,
2 is a front wheel, 3 is a rear wheel, 4 is a seat, and 5 is an exhaust pipe.

The above engine E has a common upper part of the crankcase 6 (
It has a total of four cylinders: two cylinders 5ISS3 (not visible in the figure) on the front side (on the other side), two cylinders S2 and S4 (not visible in the figure) on the front side (the other side), and the upper cylinders St, S3 and the front cylinder. S2 and S4 are arranged in a V-shape with a predetermined included angle, and the upper cylinder S
1, S3, and front cylinders S2, S4 are arranged alternately in the crankshaft direction (direction perpendicular to the plane of paper in FIG. 1) at predetermined intervals.

The above four cylinders 81 to S4 have substantially the same configuration, with upper cylinders Sl and S3 and front cylinders S2 and S.
4 is arranged symmetrically with respect to the bisector of the included angle of both cylinders. The intake passages 7 of each of the cylinders 81 to S4 are concentrated between the two cylinders and are oriented toward the obliquely upwardly curved blade, and are connected to the respective carburetors 8 disposed between the two cylinders. In addition, the exhaust passage 9 is connected to the "-" side cylinder S.
The cylinders t and S3 are oriented rearward, and the front cylinders S2 and S4 are oriented downward, and are connected to respective exhaust pipes 5 extending rearward. In FIG. 1, l0111 is a radiator.

Further, as shown in FIG. 2, the exhaust passage 9 of each cylinder 5l-S4 arranged as above is connected to the engine
A plate-shaped valve body 20 is provided for adjusting the exhaust timing according to the rotation speed of the engine. The valve body 20 is provided at the upper part of the exhaust passage 9, that is, on the side of the cylinder head 21, and its base end is fixed to a valve body support shaft 23 arranged parallel to the crankshaft 22, so that the valve body 20 can swing freely.

Then, by rotating the valve body support shaft 23 and swinging the valve body 20, the upper end position of the exhaust boat 24 of the cylinder can be substantially raised or lowered by the swing end portion formed in a shape along the inner wall of the cylinder. It is now possible to change the exhaust timing by moving the In this case, the exhaust boat 24
is divided into two parts with a rib 25 in between, and two valve bodies 20 are also provided.

This configuration is common to each cylinder 5l-S4, and all parts such as the valve body 20 and the valve body support shaft 23 are common.

FIG. 3 shows the relationship between the cylinder 5l-S/l and the valve body support shaft 23, and the relationship between the valve body support shaft 23 and its interlocking control device 26 in an expanded manner. Cylinder S1 and cylinder S3 are lined up in a direction parallel to crankshaft 22, and valve body support shaft 23.2 provided in these cylinders S1 and S3
3 are arranged on the same straight line. And cylinder S
! Valve body, support shaft 23 and valve body support shaft 23 of cylinder S3
but,.

They are connected by a connecting fitting 27. Connecting fitting 2 in this case
In 7, an engagement hole 27a with the connecting bolt B is formed in a long hole shape extending in the circumferential direction, and by adjusting the engagement position with the bolt B along the shape of the engagement hole 27a, both The valve bodies 20 in the cylinders S1 and S3 can be adjusted at the same time.

The same applies to the front cylinders S2 and S4, and the valve body support shafts 23, 23 are connected to each other by a connecting fitting 27 similar to that described above. Then, the lower ends of the valve body support shafts 23 provided in the cylinders S1 and S2 in FIG. 3 protrude from the outer surface of each cylinder block, and by rotating these parts, each cylinder 51-S/! The valve body 20 can be swung.

On the other hand, as shown in FIG. 2, one drive shaft 30 is arranged below the carburetor 8 to provide a predetermined rotational movement to the valve body support shaft 23 of each cylinder 5l-94. . This drive shaft 30 is common to all the cylinders 81 to S4, and is rotatably provided parallel to the crankshaft 22. This drive shaft 30 is set to have a length that is approximately the same as the displacement dimension Il of the cylinders Sl and 52 in the crankshaft direction, and the base end of one interlocking mechanism +M31 is connected to the end closer to the cylinder. The base end of the other interlocking mechanism 32 is connected to the opposite end.

The interlocking mechanisms 31 and 32 respectively control the rotation of the drive shaft 30 to the respective valve body support shafts 2 of the upper cylinder Sl and the front cylinder S2.
3, and is configured as a link mechanism.

That is, the interlocking mechanism 31 includes an arm 33 whose base end is fixed to the drive shaft 30, a length-adjustable rod 34 rotatably connected to the distal end of the arm 33, and a rotatable rod 34 at the distal end of the rod 34. The distal end of the arm 35 is fixed to the protruding end of the valve body support shaft 23 of the cylinder S2.

The interlocking mechanism 32 also includes a reel 36 whose center is fixed to the drive shaft 30, a length-adjustable rod 37 rotatably connected to the outer circumference of the reel 36, and a length-adjustable rod 37 rotatably attached to the tip of the rod 37. The distal end of the arm 38 is fixed to the protruding end of the valve body support shaft 23 of the cylinder S1. By rotating the drive shaft 30 via the wire 39 wound around the reel 36, the valve bodies 20 of the cylinders S1 to S4 can be operated in conjunction with each other.

By the way, this engine is characterized in that all the parts for each of the cylinders S1 to S4 constituting the exhaust timing control device are made common, and each cylinder 5t-84 has almost the same structure.

A V-type four-cylinder engine is constructed by changing the orientation of the six cylinders 81 to S4 and arranging them at predetermined locations. The cylinder 5ISS3 on the right side of FIG. 3 and the cylinders S2 and S4 on the left side are simply opposite in direction.

That is, first, the structure of the cylinder block of each cylinder 5l-84 is exactly the same. Next, the structure of the valve body 20,
The structure 6 of the valve body support shaft 23 that supports it is the same, and the valve body support shaft 23 is inserted into the cylinder block from the same direction.

Then, it is supported f4f in exactly the same form by various supporting parts.
Supports t23.

In this way, when the structure of each cylinder 5l-S4 is made common, the driving side end of the valve body support shaft 23 of the upper and lower side cylinders is moved in the crankshaft direction due to the addition of the displacement dimension H of the cylinders 5l-S4. There will be some deviation. The deviation size is shown on the right side of Fig. 3. However, this engine E
In this case, by providing the drive shaft 30 and the interlocking units +M31, 32, the deviation can be absorbed by appropriately determining their dimensions. As a result, the cylinder side parts can be made common. Therefore, in this engine E, since each cylinder 81 to S4 has a common structure, a reduction in parts cost is achieved.

Also, to assemble this, first install the cylinder block and crankcase 6? Prior to this fixation, the valve body 20, valve body support shaft 23, etc. are assembled into each cylinder block. In this case, each cylinder 81 to S4 is assembled in exactly the same way. Then, the cylinder block is fixed to the crankcase 6 in a predetermined orientation. After that, the valve body support shafts 23 of the cylinders S1 and S3, and the cylinder S
2. Connect the S4 valve body support shafts 23 to each other with the fittings 27
Connect with. Finally, the tips of the interlocking mechanisms 31 and 32 are connected to each valve body support shaft 23. By doing this,
Engine E equipped with an exhaust timing control device is assembled. In this way, the engine E equipped with the exhaust timing control device can be manufactured by simply assembling cylinders with the same structure and fixing them to the crankcase 6 in a predetermined direction, making assembly extremely easy. Products can be provided at low prices.

As described above, in the device of the embodiment, each cylinder 8
A common drive shaft 30 is provided for S1 to S4, and the base ends of interlocking mechanisms 31 and 32 are connected to one end and the other end of this drive shaft 30, respectively, and the distal ends of these interlocking mechanisms 31 and 32 are connected to the front cylinder S2. The valve body support shaft 23 of the upper cylinder S1 is connected to the valve body support shaft 23 of the upper cylinder S1. It is possible to absorb the deviation L between the drive side ends, and also to standardize the parts on the cylinder 5l-34 side.

In the above embodiments, a V-type four-cylinder engine has been described, but the present invention can be applied to any V-type two-stroke engine regardless of the number of cylinders.

In addition, in the above embodiment, a case was shown in which a link mechanism was used as the interlocking mechanism, but if the function of transmitting the rotation of the drive shaft 1 & to the valve body support shaft is performed, a link mechanism + 1 is used.
It is possible to use not only the Vt type but also the wire type.

[Effects of the Invention] As described above, according to the present invention, by appropriately determining the length of the drive shaft and the dimensions of the interlocking mechanism, it is possible to absorb the misalignment between the drive side ends of the valve body support shaft. This makes it possible to standardize the cylinder side parts. Therefore,
It is effective in reducing component costs and assembly costs, and can provide products at low prices.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings are diagrams for explaining one embodiment of the present invention, and FIG. 1 is a side view of a motorcycle equipped with the engine of the embodiment, and FIG. 2 shows a part of the engine. FIG. 3, which is a side view taken from section B, is an expanded view of the drive system of the exhaust timing control device. E... V-type 2-stroke engine, Sl-S4.
...Cylinder, 9...Exhaust passage, 20.
... Valve body, 22 ... Crankshaft,
23... Valve body support shaft, 24... Exhaust boat, 30... Drive shaft, 31.32...
・Interlocking tank.

Claims (1)

[Claims] A V-type two-stroke engine has a cylinder on one side and a cylinder on the other side arranged at a predetermined included angle and at a constant interval in the direction of the crankshaft. In addition to arranging the valve body, a valve body support shaft is arranged for each cylinder so as to be parallel to the crankshaft, and the valve body is supported by these valve body support shafts so as to be able to swing freely, and the valve body is supported. By rotating the shaft and swinging the valve body, the top end position of the exhaust boat of each cylinder is substantially moved up and down by the swinging end,
In an exhaust timing control device for a V-type two-stroke engine that changes the exhaust timing, a drive shaft common to the one cylinder and the other cylinder is provided parallel to the crankshaft, and a drive shaft is provided at one end and the other end of the drive shaft. A V-type two-stroke engine characterized in that the base ends of the interlocking mechanisms are connected, and the distal ends of these interlocking mechanisms are connected to the valve body support shaft of one side cylinder and the valve body support shaft of the other side cylinder, respectively. Exhaust timing control device.