JPS60156925A - Exhaust port controller for two-cycle engine - Google Patents

Abstract

PURPOSE:To aim at improvements in output of power over a wide range, by making a main exhaust port and two auxiliary exhaust ports at both sides of the former open to a two-cycle engine separately, while installing a valve, which regulates the interconnection between a expansion chamber and these main and auxiliary exhaust ports, and controlling the valve according to an engine speed. CONSTITUTION:A main exhaust port 15 and two auxiliary exhaust ports at both sides of the former are made open to a cylinder 10 of a two-cycle engine separately, while each of regulating valves 18 and 19 are installed in position between these exhaust ports 15 and 16 and an expansion chamber 21. These valves 18 and 19 make the main exhaust port 15 and the expansion chamber 21 get them interconnected in time of low speed in the engine, and in proportion as it comes to high speed, the expansion chamber 21 is gradually closing to the main exhaust port 15, while the auxiliary one 16 is controlled so as to open by degrees instead.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exhaust port control device for a two-cycle V engine mounted on a motorcycle or the like.

(Prior Art) A conventional exhaust hole control device for a 2-cycle engine is equipped with an auxiliary exhaust 7L2 above the main exhaust hole 1, as shown in FIG. It communicates with the pulp 8 via the pulp 8 so that it can be opened and closed.

That is, the exhaust cross-sectional area of the exhaust hole is changed by opening and closing the auxiliary exhaust hole 2 due to the rotation of the pulp 8, so as to match the rotational speed of the engine.

However, with the above structure, it is not possible to expect an improvement in the output direction in the low speed range of engine rotation. In other words, due to the pulsation of the exhaust gas, the output does not increase significantly in the low speed rotation range.

In order to increase the output direction in the low-speed rotation range, a model in which the expansion chamber is communicated with the exhaust hole has been developed, but there remains a problem with the output in the high-speed rotation range.

(Objective of the invention) An object of the invention is to significantly improve engine output in any rotation range from low speed to high speed.

(Structure of the Invention) (a) An exhaust expansion chamber is provided, and auxiliary exhaust holes opening into the cylinder are provided on both sides of the main exhaust hole, (b) each auxiliary exhaust hole is provided with an opening/closing adjustment valve l leg, c) Each opening/closing control valve allows each auxiliary exhaust hole to be opened and closed with respect to the main exhaust hole, and at the same time, the expansion chamber can be opened and closed with respect to the main exhaust hole, and d) When the engine rotation is in a low speed range, the main exhaust The above-mentioned valve is arranged such that the expansion chamber opens with respect to the hole and the auxiliary auxiliary exhaust hole closes, and as the engine rotation increases to 1π speed, the expansion chamber closes in line with the main exhaust hole and the auxiliary auxiliary exhaust hole opens. It consists of

(Embodiment) In FIG. 2, 10 is a cylinder, 11 is a crankcase, and 12 is a piston, in which a suction hole 1B and a scavenging hole 14 are formed in the cylinder lO, and a main exhaust hole 15
is formed. The suction hole 13 is equipped with a reed valve 7 and is opened and closed with respect to the crank chamber 8 by the vertical movement of the piston 12. The scavenging hole 14 has a lower end opening into the crank chamber 8 and an upper end opening into the piston 12.
It opens and closes in the cylinder 10 by vertical movement of the cylinder.

In Figure 3 showing the ■-■ cross section of Figure 2, the main exhaust hole 1
There are first and second auxiliary exhaust holes 1 on both sides of the cylinder 5 in the circumferential direction.
6.17), each auxiliary exhaust hole 16.17 opens independently into the cylinder 10, and first and second opening/closing adjustment pulps (rotating The valves are connected to each other via valves 18 and 19 so as to be openable and closable.

Reference numeral 20 denotes an expansion chamber cover, which forms an expansion chamber 21 by being fixed to the cylinder 10.

The expansion chamber 21 is located in the first chamber of the cylinder 10. Second expansion passage 23.
It is connected to 24. The first expansion passage z8 leads to a first opening/closing adjustment plug 18, which allows the first expansion passage z8 to freely open and close with respect to the main exhaust hole 15.

The second expansion passage 24 reaches a second opening/closing control valve 19, which allows the valve 19 to freely open and close the main exhaust hole 15.

Both pulps 18 and 19 are formed into shaft shapes parallel to the cylinder center line, and are rotatably supported by the valve boss portion 25 of the cylinder 10. The valves 18, 19 are each formed with a partially arcuate cutout channel 26, 27.

When each auxiliary exhaust hole 16.17 is closed to the main exhaust hole 15, the expansion chamber 21 opens to the main exhaust hole 15 via the respective passage 2B, 14 and the cutout passage 26.27; When each auxiliary exhaust hole 16, 17 is open to the main exhaust hole 15 as shown in Figure 4, the expansion chamber 21 is open to the main exhaust hole 1.
It is designed to close against 5.

Both pumps 1B and 19 are interlocked and connected to, for example, a governor device 30 (Fig. 6) via a rack shaft 28, etc., and when the engine rotation speed is low, the state shown in Fig. 8 is maintained, and the engine rotation is As it rises, the first opening/closing adjustment valve 18 rotates in the direction of arrow A, and the second opening/closing adjustment valve 19 rotates in the direction of arrow B.

That is, in FIG. 5, both the pulps 18 and 19 are arranged on both sides of the rack shut 28, and are each integrally provided with pinions 81 and 82.
2 mesh with the teeth 8B and 84 of the rack shaft 28, respectively. The rack shaft 28 is axially movably supported by a boss portion 85 and the like, extends into the transmission chamber 36, and is provided with a pair of adjustment plates 37 in a portion inside the transmission chamber 86. A vertical pin 39 of a rotating arm 88 is held between both adjustment plates 87, and the rotating arm 38 is fixed to a vertical rotating wheel 40.

An arm 42 having a vertical pin 41 is fixed to the lower end of the rotation shaft 40, and the pin 41 is held between a pair of annular adjuster plates 44 of a slider 43.

The slider 48 is fitted to the governor rotating shaft 45 so as to be slidable in the axial direction.
It is designed to rotate 0.

In FIG. 6, which shows a cross section taken along the line ■-■ in FIG.
．． It is a so-called centrifugal ball type governor device, which is equipped with a plurality of centrifugal poles 48 sandwiched between 47, a governor spring 49, and the like. One spherical plate 47 is the slider 4B.
It is equipped with the following. The governor spring 49 is compressed between the adjuster plate 44 and the governor drive gear 51, and moves the spherical plate 47 through the plate 44 in the direction of the reverse arrow E.
direction (Figure 5). The drive gear 51
is fixed to the panna rotating shaft 45, and is attached to the crankshaft 5.
It meshes with the crank gear 56 of No. 5. In FIG. 6, 57 is a bearing, and 58 is a boss member that rotatably supports the vertical rotation shaft 40.

FIG. 7 is a developed partial view of the inner circumferential surface of the cylinder, showing the shapes of the openings of the main exhaust hole 15, the auxiliary exhaust holes 16, 17, and the scavenging hole 14, as well as their mutual positional relationships. That is, the upper edges of the openings of the main exhaust hole 15 and the auxiliary exhaust holes 16 and 17 are aligned at the same height, and the vertical length of the opening of each auxiliary exhaust hole 16 and 170 is equal to the opening of the main exhaust hole 15. It is less than half the length of the top and bottom of the section. A scavenging hole 14 opens below the opening of each auxiliary exhaust hole 16,17.

(Function) When the engine rotation speed is low, use the centrifugal pole 4 in Fig. 6.
No centrifugal force acts on slider 48, and slider 48 moves in the direction of arrow E.
It does not slide in any direction. For this purpose, both pulps 18 and 19 are maintained in the state shown in FIG. That is, the expansion chamber 21 is fully opened from both sides in the middle of the main exhaust hole 15 via both expansion passages 2B and 24, and the auxiliary exhaust hole 16.1
7 is completely closed to the main exhaust hole 15. Therefore, the exhaust cross-sectional area corresponds to the cross-sectional area of the main exhaust hole 15, and is suitable for the engine characteristics at low speeds.
1 absorbs exhaust pulsation and improves output.

As the engine speed increases, the rotational speed of the governor rotating shaft 45 in FIG.
The centrifugal force applied to l'48 increases, and the centrifugal force overcomes the elastic force of the governor spring 490, causing the ball 48 to move outward, causing the slider 43 integrated with the spherical plate 47 to slide in the direction of arrow E. As the slider 480' slides, the vertical rotation shaft 40 rotates in the direction of arrow C via the pin 41 and arm 42 in FIG. 5, and the rack shaft 28 moves in the direction of arrow C via the arm 38, bottle 39, etc. do. As the rack shaft 28 moves in the direction of arrow C, each pinion 81.
32, the first opening/closing control pulp 18 in FIG.
At the same time as the opening/closing adjustment pulp 19 rotates in the direction of the arrow B, the expansion book chamber 21 opens into the main exhaust hole 15.
, and both auxiliary exhaust holes 16.
17 is inserted into the main exhaust hole 15 and gradually opens.

In other words, the exhaust cross-sectional area becomes the cross-sectional area of the main exhaust hole 15 plus the cross-sectional area of both opened auxiliary exhaust holes 16 and 17, and is expanded to match the engine characteristics at high speeds.
, the output is improved. Further, since the expansion chamber 21 is gradually closed, the exhaust flow is not disturbed even if the speed of the exhaust flow increases with the increase in rotational speed. That is, both auxiliary exhaust holes 16.
17 will not be obstructed in the exit direction by opening. Note that since the exhaust pulsation naturally decreases as the engine speed increases, there is no fear that the exhaust pulsation will increase due to the expansion chamber 21 being closed.

When the engine speed overruns or reaches maximum speed,
As shown in FIG. 4, the auxiliary exhaust hole 1 is connected to the main exhaust hole 15.
6.17 is fully opened and the exhaust cross-sectional area is the maximum of the cross-sectional area of the main exhaust hole 15 plus the total cross-sectional area of both auxiliary exhaust holes 16.17), when the engine is on overrun or at maximum speed. It will be worth it. Further, the expansion chamber 21 is completely closed off from the main exhaust hole 15, so that the exhaust flow is not disturbed. Also, auxiliary exhaust holes 16 and 17 on both sides of the main exhaust hole 15
Since both are fully open, there is a great effect on the exit direction in the event of an overrun.

In the illustrated embodiment, the valves 18, 19 disposed on both sides of the main exhaust hole 150 are configured to rotate in opposite directions, so that the expansion chamber 21 and each pulp 18, 19 are rotated in opposite directions.
The arrangement structure of the expansion passages 2B, 24, etc. that connect the two is simple.

(Another embodiment) (1) In the illustrated embodiment, one expansion chamber is branched and connected to two on-off control valves, but two expansion chambers are provided, and one expansion chamber is provided for each on-off control valve. You can also connect them one by one.

(2) Two opening/closing control valves can also be interlocked and connected by a link mechanism or the like.

(3) The two opening/closing control valves can also be set so that their opening/closing timings are shifted from each other. That is, the valve opening/closing timing is set according to engine specifications and the like.

(4) As a drive mechanism for the opening/closing control valve, there is an engine rotation speed detection device, a puff ref transmission device whose pulse signal transmission amount changes depending on the rotation speed, and a servo motor whose rotation angle changes according to the pulse transmission amount. A servo motor can also be linked to both pulps.

(5) As shown in FIG. 8, the upper and lower ends of the openings of both auxiliary exhaust holes 16 and 17 are aligned with the heights of the upper and lower ends of the opening of the main exhaust hole 15, respectively (effects of the invention). (1) When the engine rotation is in a low speed range, the auxiliary exhaust hole closes and the exhaust cross-sectional area becomes small, and as the engine speed increases, the auxiliary exhaust hole opens and the exhaust cross-sectional area increases. During overrun or maximum speed, both auxiliary exhaust holes are fully opened and the exhaust cross-sectional area is maximized, so the engine characteristics remain almost constant, and the auxiliary exhaust holes can be opened efficiently, especially in the high speed range. The availability of this product is particularly noticeable in the direction of departure.

(2) Since the expansion chamber opens to the main exhaust hole when the engine speed is in the low-speed rotation range, it is possible to absorb exhaust pulsation, which is generally a problem in the low-speed rotation range. It also improves output in the area. Further, as the engine rotation speed increases, the expansion chamber closes, so that the expansion chamber does not cause disturbance in the exhaust flow in the high speed rotation range, and the above-mentioned auxiliary exhaust hole does not obstruct the exhaust flow in the upward direction.

(8) Since there are two auxiliary exhaust holes and they are provided on both sides of the main exhaust hole, the air loss cross section can be increased symmetrically, and the amount of increase in the exhaust cross section can also be sufficiently increased. It can be made larger, thereby making it more noticeable in the output direction in the high speed rotation range.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional example, FIG. 2 is a longitudinal sectional view of a 2ZAIK M engine to which the present invention is applied, and FIG. Ill sectional view, 4th
The figure is a llll-III sectional view of Fig. 2 showing the state of maximum speed rotation, Fig. 5 is a partial cross-sectional view of V-■ of Fig. 2, and Fig. 6 is a Vl -11'vrR sectional view of Fig. 5. FIG. 7 is a developed partial view in the direction of arrow 2 in FIG. 3, and FIG. 8 is a developed partial view of the inner circumferential surface of the cylinder of another embodiment. IO...Cylinder, 15...
・Main exhaust hole, 16.17...Auxiliary exhaust hole, 18.19
...opening/closing control valve, 21...expansion chamber patent applicant
Kawasaki Heavy Industries Co., Ltd. Figure 1 Figure 2 Figure 7 Procedure amendment fee (voluntary) February 29, 1980 Application No. 248125 2, Name of the device 2' + Exhaust port control device for a noise engine 3, Person making the correction f1 Which relationship Special r Title name
(097) Kawasaki Heavy Industries stock rights representative Hase iJ1
! Hiroshi 4, Agent address: 10th floor, East Building, Chiyoda Building, 2-9-4 Higashitenma, Kita-ku, Osaka (Ai 530) 5. Date of amended order. Delivery address: 11r.
Day 6, Subject of amendment Application and Mei 1111 NJ8, Correction iS type [1 record Application, specification, 1 or more copies each

Claims (1)

[Claims] In addition to being equipped with an exhaust expansion chamber, auxiliary exhaust holes that open into the cylinder are provided on both sides of the main exhaust hole, and each auxiliary exhaust hole is provided with an opening/closing adjustment pulp, and each auxiliary exhaust hole is connected to the main exhaust by each opening/closing adjustment pulp. At the same time, the hole can be opened and closed freely.
The expansion chamber can be opened and closed with respect to the main exhaust hole, and when the engine rotation is in a low speed range, the expansion chamber opens with respect to the main exhaust hole and both auxiliary exhaust holes close, and as the engine rotation becomes high speed, the expansion chamber opens and closes with respect to the main exhaust hole. An exhaust hole control device for a two-stroke V engine, characterized in that the pulp is configured such that both auxiliary exhaust holes open as the expansion chamber closes.