JPS5825515A - 2-cycle engine for autobicycle - Google Patents

Abstract

PURPOSE:To form an engine to small length axially of a crankshaft, by arranging two cylinders in a V type, providing a carburetor between said cylinders and arranging a common disc valve in a parallelly arranged intake passage. CONSTITUTION:An engine is provided with two cylinders 12 vertically in a V type. A carburetor 27 is arranged between the both cylinders 12, and a common disc valve 28 is arranged in an intake passage 26 connecting the carburetor 27 to a crank chamber 22. Crankshafts 21 of each cylinder 12 are connected to an output shaft 36 through minor reduction gears 35 and major reduction gear 33 to drive a wheel. In this constitution, the disc valve is not largely protruded sideward of the engine, and the engine can be formed to shorter length axially of the crankshaft, permitting the large permissible angle of bank at turning motion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clusterer chamber precompression type two-row engine in which the intake passage is communicated and disconnected by an f-disc valve, and in particular, it is possible to shorten the length of the engine in the crankshaft direction. It is suitable for the required motorcycle engine.

A two-stroke engine using a disc valve is superior to a piston valve type in that it is easier to set the opening and closing timing of the valve at will, and is smaller in size than a reed valve type. Due to its low ventilation resistance, it is suitable for motorcycle engines that require a high specific output [W]. Therefore, conventionally, a disc valve was attached to the crankshaft and a carburetor was installed on the blank side (for example, in 1983-
20324). However, when the engine is configured in this way, the feldspar in the direction of the engine's crankshaft becomes longer. In addition, in a motorcycle mounted with the engine or crankshaft oriented in the left-right direction of the vehicle, the width of the vehicle is too large and it is impossible to increase the allowable angle of inclination when turning.

The present invention has been developed to eliminate such unpleasant smells.Hereinafter, the present invention will be explained with reference to the illustrated embodiments. FIG. 1 shows a motorcycle 1 for use as a bicycle. That is, a front fork 4 having a front axle 3 is provided at the front of the body frame 2 so as to be able to turn left and right, and a rear arm having a rear wheel 5 is supported at the rear so as to be swingable up and down. T is body frame 2
The water-cooled two-stroke engine was mounted in the lower center of the engine, and the engine cooling water radiator was installed in front of it. 9 is a drive chain extending between the engine T and the rear wheels 5, 10 is a fuel tank, and 11 is a passenger seat.

The engine 1 has two cylinders 12 and 121 arranged vertically in a V-shape, each cylinder having a
Exhaust pipes 14, 14 are connected 13.

Each exhaust pipe 14.14 extends rearward passing directly above and below the engine 1, and an exhaust silencer 141 is arranged in stages 6 at its rear end. Since the cylinders 12.12 have a similar construction, one of them is shown in FIG. The piston 11 has pistons 1T and 1T which are freely inserted, and a combustion chamber 18 is formed on the top surface of the piston 11. 1g is the igniter. Reference numeral 21 denotes a crankshaft, which is housed in the crank chamber 22 and has connecting rods 23 and 21.
The piston 11 is connected through the piston 11. 24 is a scavenging passage, and 111.25 is an exhaust passage. The above configuration is not particularly different from the conventionally known Nigyofuku engine. The actual engine has two two-stroke engines having the above-mentioned component pipes, which are arranged in a V-shape, and are connected to each other by a reduction gear 33, which will be described later, and the inside of the crank chamber 22 is communicated between them. The intake passages 26.2 for each cylinder are juxtaposed adjacent to each other. 27 is the carburetor, and 27m is its piston type throttle valve. A disk valve 28 is provided between the intake passage 26 and the carburetor spindle chamber 22. That is, the disc valve 20 is connected to the crank chamber 220 case and the lid member 2.
Valve 11 is placed with a small gap between the pipe and the valve 11! The connecting stone rotates once every 1 rotation of the crankshaft by $1.

28m is inserted into the disc valve 28' by two valve ports provided symmetrically to the valve shaft 31. A bevel gear 31a is provided along the axis of the valve shaft 31, and meshes with a large reduction gear 33 via an intermediate gear portion 1t32t. Note that the valve 11131 may be arranged so as to extend in a direction perpendicular to the crankshaft 21, as shown by the solid line in FIG. Therefore, the disk valve 28 pipe can be entirely accommodated between the two cylinders 12, 12. The large reduction gear 3s is connected to the speed change gear IIO and the gear shaft IIK through the gear wheel 314We, and is also connected to the crankshaft 21 through the stopper wheel SS pipe. 36 is transmission gear group 3
The output shaft driven by the input shaft 3s via 7t is engaged with the sprocket 138 that drives the drive chain 9t. 8$1 is a cooling water pump that circulates cooling water between the cooling jacket 1S and the radiator.

Next, the operation of this actual example will be explained. When the crankshaft 21 is cranked and the piston 11 begins its upward stroke,
The disk valve 28 rotates and the valve port 28a opens the intake passage 24.
If: You can get pregnant continuously. Then, the mixture generated in the carburetor 27 and metered by the throttle valve 27m is transferred to the crank chamber 22.
introduced into the world. When the piston 17 moves to the downward stroke, the disk valve 28 cuts off the intake passage 241, so the air-fuel mixture introduced into the crank 1T is compressed, and as the piston 1T further descends, the scavenging passage 24 and combustion Room 1
When it opens in 8, it flows into the inside oppositely. piston 1
1 or higher, and when it reaches the end of the compression stroke, the ignition I & 11
Ignition is carried out by
The piston 1T is pushed down with force. When the downward stroke reaches the middle stage, the exhaust passage 25 opens and the burnt gas in the combustion chamber 18 is discharged as exhaust gas.

The output of the primary engine obtained in this way is crank @2
1 is transmitted to the transmission gear group 3T by the small #1 deceleration wheel 35 and the large gear 33, and is taken out from the drive sprocket 38 provided at the end of the output shaft and drives the rear wheel 5 via the drive chain 9. .

The above two-stroke 2/jin is mounted on the motorcycle 1 with the two cylinders 12゜12 in front, and the disc valve 2
8 is located above the crankshaft of the lower cylinder 12. Further, the intake passage 26 is oriented in the direction in which the vehicle is traveling, so that the wind pressure of the traveling wind is received while the vehicle is running.

As described above, this invention provides an exhaust vent A on one side of the cylinder in a motorcycle in which the crankshaft is arranged in the left-right direction of the vehicle. ml! t. Since the disc valve installed in the intake passage is arranged on the side of the cylinder except for the connection part of the exhaust passage, the disc valve does not protrude greatly to the side of the engine. Therefore, even if the vehicle tilts due to turning, the disge valve will not get in the way. t
In addition, since the disc valve is placed at a higher position than the second link shaft, the above-mentioned problem will not occur even if the disc valve is moved to the side of the engine.

[Brief explanation of the drawing]

The drawings show a complete example of Motoakiaki, and Figure 11!1 is a side view of a competition motorcycle, and Figure 2 is a partially destroyed engine.
The r1li side view and the 3rd side view are system diagrams showing the engine power system. T...Engine, 12...Cylinder, 22...
・-Crank chamber, 2@...-Intake passage, 27--...
Carburetor, tS...Disc valve, 31...Self-valve shaft. Patent Applicant Yamaha Motor Co., Ltd. Agent Masaki Yamakawa (one person behind the scenes) Procedural Amendment (spontaneous) Date of Showa Date: July 141, 1939 To the Commissioner of the Japan Patent Office
, Indication of the case 1982 Patent Application No. 122435 2, Name of the invention Two-stroke engine for motorcycles 3, Person making the amendment Relationship to the case Patent Name of applicant (name)
(Mu07) Yamaha Motor Co., Ltd.'s number of inventions increases by 1 - 1 (1) 1! The claims in the specification are amended as shown in the attached sheet. (2) The phrase "This invention was made to eliminate problems with the intake passage..." in line 11 of page 1 to line 11 of page 2 will be amended as follows. "This invention relates to a KL & multi-cylinder two-cylinder precompression type two-stroke engine in which the intake passage is communicated and disconnected by a disc valve, and its purpose is to simplify the configuration of the intake passage controlled by the JLK disc valve. In motorcycle engines, it is generally required that the length in the axial direction of the cylinder be as short as possible, and for this reason, it is known that a disc valve is placed on the movement or rear side of the cylinder (for example, (Utility Model Publication No. 52-32810).However, since the same number of disc valves as the number of cylinders is required, if an engine is to have multiple cylinders, a large number of distar valves will be required, making their installation difficult. The purpose is to eliminate malfunctions, and it is configured so that the intake passages of two adjacent cylinders are controlled by a single cylinder valve, and there are 41 characteristics in 9 points.'' (3) Page 6 of the same. From line 17 to page 7, line 7, "This invention is free from any problems as described above." will be amended as follows. As described above, the ζ0 invention provides at least two cylinders close to each other in the front and back direction outside the drive case, and the carburetor connected to these cylinders is arranged between both cylinders, and the carburetor The engine and crank chamber are connected by an intake passage, and each intake passage is arranged in parallel and close to each other on the downstream side of the carburetor, and a disk valve common to each intake passage is provided in the parallel arrangement part. Therefore, it is possible to control the intake air supplied to multiple cylinders with - disc valves.In addition, there is no need for space to install disc valves, and this has the effect of preventing the engine from becoming a large building. (1) At least two cylinder two-stroke engines in the drive case. that's all

Claims (1)

[Claims] In a motorcycle with a crankshaft arranged in the left-right direction of the vehicle, the exhaust passage Yt is connected to one side of the cylinder, and a disc valve inserted in the intake passage is installed at the side of the cylinder except for the connection part of the exhaust passage. Two stroke engine arranged.