JPS6311300Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is intended to provide an engine suitable for small and portable use in brush cutters and other maintenance equipment used in a wide variety of agricultural applications. In general, the engines of this type of equipment are subject to strong vibrations, so great care is taken to install vibration isolators. Therefore, by reducing the vibrations of the engine, the vibration isolators of the machine can be omitted or reduced, which often contributes to the economic provision of the machine and the improvement of its functionality.

A detailed explanation will be given below using examples.

FIG. 1 shows a schematic cross-sectional view of the engine according to the present invention.

FIG. 2 shows a schematic diagram of the entire longitudinal section of the same as above.

The engine of this embodiment can be provided for use in a brush cutter, etc., which is equipped with an operating rod into which a transmission shaft is inserted, and a mowing blade is rotatably provided at the tip.

The engine of this embodiment is a two-stroke engine with two cylinders 3, 3 horizontally opposed to each other in a cylindrical crankcase 1, so a considerable space is formed in the upper and lower parts, and the intake air is provided in the upper part 4. As the system 5, a carburetor (diaphragm type) 30 is assembled with a heat insulating joint 31, an intake air purifier section 32, etc. to enable remote control. The exhaust ports of the cylinders 3 are visible in the lower part 6, and the mufflers of the exhaust system 7 are properly disposed at these cylinder exhaust ports to prevent a decrease in output. These upper and lower spaces are characterized in that they can be used as sufficient space for arranging the various members mentioned above.

This engine performs simultaneous ignition control, and has a structure in which the cylinders 3, 3 are offset γ to match the piston phases, and the kinetic inertia of the reciprocating parts of the engine is offset, which is the main requirement for vibration prevention. Furthermore, the lower muffler has the advantage of having sufficient space as described above, making it easier to obtain a muffler structure that is effective in silencing.

A magnetic steel flywheel 9 of a flywheel magneto with a cooling fan 8 attached to the rear part of one side of the crankcase 1 is attached to the extension part 10 of the crank rotation shaft 2, covered with a fan cover 11, and recoil. A starter 17 is integrally arranged inside the cover 11. A slit-shaped support 16 forming a cooling air intake port is disposed around the circumferential side of the recoil starter 17 to support the recoil starter 17 in order to ensure a sufficient intake port area. The fan cover 1
1 is connected to the cylinder cover 13 to form a cooling air passage 14 for the cylinders 3, 3.

Electric ignition elements 28 are respectively disposed in the passages 14 to facilitate cooling of the elements. Since the fan cover 11 has a generally elongated shape in the cylinder arrangement direction, a fuel tank 15 is disposed and attached in the upper space adjacent to the carburetor 30.

The front part of the other side of the crankcase 1 forms the front part of the engine, and has the crank rotation shaft 2 extending therethrough 20, a centrifugal clutch group 21 is rotatably attached thereto, and a lid that is assembled with the front end of the crankcase 1. body 2
3, the lid body 23 serves as a bearing for a clutch drum 22 of a centrifugal clutch device, and the shaft 24 of the drum is provided with a bore 25 and serves as an output shaft connected to a driven shaft. The mounting portion between the lid body 23 and the crankcase 1 may be a common mounting surface for various types of work equipment.

Furthermore, if a vibration isolating device is required, a separate mounting bracket 27 is provided and connected via the vibration isolating member 26.
The embodiment of the present invention shown in FIGS. 1 and 2 is an engine connected to an operating rod having a power transmission shaft inserted therein, such as that of a brush cutter. Therefore, the operator can support and carry the engine by grasping the operating stick.

Since the engine of the present invention has the above-mentioned structural arrangement, the cooling air of the engine is not subject to clogging or contamination around the engine cylinders due to the structure in which clean air is drawn in from the opposite side from the working side. Also, although the drawing shows the exhaust of cooling air directed forward, there is a way to do this by installing a buttful plate that directs it downward or around the muffler at the bottom, but this is not shown. There is.

Furthermore, the clutch drum 22 of the centrifugal clutch device is attached to the lid 23 at the front of the engine of the present invention, making the device removable and simplifying the structure of the clutch device. A feature of the engine is that the use of the engine can be easily changed by considering the structural design.

In this way, the proposed engine significantly reduces vibration compared to a single engine with the same total cylinder volume.
The wide space above and below makes it easy to arrange the intake and exhaust system parts, and it is possible to provide a compact engine with a well-organized exterior, making it a highly beneficial engine for both manufacturers and customers. .

[Brief explanation of drawings]

Figure 1: Cross section of the engine according to the present invention. Second
Figure: Same as above. Longitudinal section. 1... Crank chamber, 2... Crank rotating shaft,
3, 3...Cylinder, γ...Offset, 8...
Cooling fan, 9... Flywheel, 11... Fan cover, 14... Cooling air passage, 17... Recoil starter, 21... Centrifugal clutch shoe, 2
2...Clutch drum, 23...Lid body, 26...
Vibration isolating member, 27... Working equipment mounting bracket.

Claims (1)

[Scope of utility model registration request] As a two-cycle engine, two horizontally opposed cylinders 3, 3 are arranged with an offset γ from the crank rotation shaft 2 with respect to the cylindrical crank chamber 1, and simultaneous ignition control is performed. A flywheel magneto flywheel 9 is provided with an intake system 5 including an assembled carburetor 30, an exhaust system 7 is provided in the lower part 6 of the crankcase, and a cooling fan 8 is attached to the rear of the crankcase 1. is attached to the extension part 10 of the crank rotation shaft 2, and the outside of the flywheel 9 is surrounded by a fan cover 11 and connected to the cylinder cover 13 to form the cylinder cooling air passage 1.
4, a fuel tank 15 is arranged on the upper part of the fan cover 11, and a recoil starter 17 is supported by a slit-shaped support 16 for a cooling air intake port which is integrally provided on the outside of the rear part of the fan cover 11. A starting claw 18 of the recoil starter 17 can freely engage with a hook 19 provided on the side surface of the flywheel 9, and the crank rotation shaft 2 is extended in the front part of the crank chamber 1. 20, the centrifugal clutch group 21 is rotatably attached to the centrifugal clutch group 21, and the clutch drum 22 is rotatably supported by the lid 23 that engages with the front end of the crankcase 1, and the centrifugal clutch group 21 is attached externally to the centrifugal clutch group 21. The shaft 2 of the clutch drum 22 can be fitted freely.
Reference numeral 4 refers to a portable engine characterized in that the output shaft is provided with a bore 25 and can freely communicate with a driven shaft.