JP3572342B2 - General purpose engine - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a general-purpose engine that can be mounted on various vehicles and the like.
[0002]
[Prior art]
In general-purpose engines that can be mounted on various vehicles, etc., a crankshaft is pivotally supported on a crankcase, and power is taken out by penetrating this crankshaft from the crankcase, but this power is taken directly from the crankshaft. There is a type in which power is transmitted from a crankshaft to an auxiliary output shaft by a chain, a gear, or the like and taken out from the auxiliary output shaft.
[0003]
[Problems to be solved by the invention]
As described above, the power taken directly from the crankshaft and the power taken out from the auxiliary output shaft use dedicated crankcases, respectively, so that the production cost is high and quality control and the like need to be performed for two types. There is and is troublesome.
[0004]
The present invention has been made in view of such a situation, and regardless of the difference in the method of taking out the power, at least the use of at least the crankcase material is reduced, the cost is reduced, and the quality control is simplified. It aims to provide an engine.
[0005]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, the present invention is configured as follows.
According to the first aspect of the present invention, a crankcase that supports a crankshaft can be divided in the crankshaft direction, and the crankshaft passes through the crankcase so that one end of the crankshaft extends from the outer surface of the crankcase. In a general-purpose engine in which power is directly taken out from one end of the crankshaft,
When the power of the crankshaft is taken out from the outer surface of the crankcase via an auxiliary output shaft,
A boss portion that supports one end of the auxiliary output shaft, and a seal portion that joins a lid that supports the other end of the auxiliary output shaft, on the side that takes out the power of the crankshaft via the auxiliary output shaft, The seal is formed on an outer surface on the same side of the crankcase, and the seal surrounds the crankshaft and the boss.
[0008]
[Action]
In the invention described in claim 1, the crankcase is formed with a boss portion that supports one end of an auxiliary output shaft to which power is transmitted from the crankshaft, and a seal portion that surrounds the crankshaft and the boss portion. the crankcase, may be used in combination with scheme takes power directly from the crankshaft and to the method of taking out from the auxiliary output shaft.
[0011]
【Example】
Next, an embodiment of the general-purpose engine of the present invention will be described in detail with reference to the accompanying drawings. First, a general-purpose engine that extracts power directly from a crankshaft will be described. 1 is a front view of a general-purpose engine, FIG. 2 is a plan view of the general-purpose engine, FIG. 3 is a rear view of the general-purpose engine, FIG. 4 is a right side view of the general-purpose engine, FIG. FIG. 7 is a cross-sectional view of the general-purpose engine in the cylinder axis direction, FIG. 8 is a cross-sectional view of the general-purpose engine in the crankshaft direction, and FIG. 9 is IX-IX of FIG. FIG. 10 is a plan view of a cylinder head and an air shroud incorporating a valve operating mechanism, FIG. 11 is a plan view of a throttle lever adjusting mechanism, and FIG. 12 is a side view of a throttle lever adjusting mechanism. 13 is a sectional view taken along the line XIII-XIII in FIG.
[0012]
The general-purpose engine 1 is configured such that the crankcases 2 and 3 can be divided into two in the crankshaft direction, and the crankshaft 6 is rotatably supported on the crankcases 2 and 3 via bearings 4 and 5. Seals 7 and 8 are provided outside the bearings 4 and 5, respectively. A cylinder body 9 is formed integrally with the crankcase 2, and a cylinder head 10 is attached to the cylinder body 9. The cylinder body 9 and the cylinder head 10 have cooling fins 9a and 10a, respectively. A piston 11 is provided on the cylinder body 9 so as to be able to reciprocate. The piston 11 is connected to the crankshaft 6 via a connecting rod 12. A pulley 13a provided at the right end of the crankshaft 6 is provided with a permanent magnet 13b, which is a part of the ignition device 13 and generates a charge for ignition, and a fin 14 is attached to the pulley 13a. It is integrally molded. The fins 14 absorb the outside air from the cooling air inlet 16 provided in the engine cover 15 into the engine cover 15 to forcibly cool the general-purpose engine 1.
[0013]
The crankshaft 6 is started by a recoil starter 17. The recoil starter 17 is mounted on a recoil starter case 18 and driven by an operation lever 19, and forcibly rotates the crankshaft 6 to start the general-purpose engine 1. The recoil starter case 18 is fixed to the engine cover 15 with bolts 20.
[0014]
In the cylinder head 10, an intake valve 21 and an exhaust valve 22 open and close an intake passage 24 and an exhaust passage 25, which open to a combustion chamber 23, at a predetermined timing by a valve mechanism 26. The valve mechanism 26 includes a camshaft 27 that rotates in conjunction with the crankshaft 6, cam rods 28 a and 28 b that are operated by cams 27 a and 27 b of the camshaft 27, and a rocker arm 29 a that pushes the intake valve 21 and the exhaust valve 22. , 29b. An ignition plug 30 is attached to the cylinder head 10 so as to face the combustion chamber 23.
[0015]
An exhaust pipe 31 is connected to the cylinder head 10 in communication with the exhaust passage 25, and a muffler 32 is connected to the exhaust pipe 31. The muffler 32 is arranged above the crankcase 3 and is supported by the crankcase 2 via a support bracket 33. The support bracket 33 is fastened and fixed to the upper part of the crankcase 2 with bolts 34. Further, an intake pipe 35 is connected to the cylinder head 10, a carburetor 36 is connected to the intake pipe 35, and an air cleaner 37 is connected to the carburetor 36, and the air cleaner 37 is disposed on a side of the general-purpose engine 1. Have been.
[0016]
A fuel hose 38 is connected to the carburetor 36, and the fuel hose 38 is connected to a fuel cock 39. The fuel cock 39 is attached to the bottom of the fuel tank 40. The fuel tank 40 is disposed above the crankcase 2, and a mounting flange portion 40 a provided around the fuel tank 40 is fastened and fixed to the left and right mounting brackets 41 and 42 with bolts 43 and 44, and the left and right mounting brackets 41. , 42 are fastened and fixed to the upper part of the crankcase 2 by bolts 45, 46, respectively.
[0017]
The carburetor 36 is connected to a governor arm 48 via a rod 47. The governor arm 48 is fixed to an output shaft 50 of a governor device 49 built in the crankcase 2, and rotates according to the rotation speed of the engine. The rod 47 is provided with a spring 51 so that the rotation of the governor arm 48 can be transmitted to the vaporizer 36 without loss. A stay 52 is attached to the governor arm 48, and the stay 52 is connected to a throttle lever 54 via a governor spring 53. The throttle lever 54 is rotatably supported by a support pin 56 of a bracket 55, and the bracket 55 is fastened and fixed to the crankcase 2 together with the bracket 42 by a bolt 46. When the throttle lever 54 is in the low idle state at the position shown in FIG. 2, in this low idle state, since the end of the governor spring 53 is engaged with the long hole 54 a of the throttle lever 54, the governor spring 53 is pulled. No force is acting. The bracket 55 is provided with a screw 58 for setting the high idle speed of the governor device 49, and the throttle lever 54 rotates counterclockwise so that the stopper 54b of the throttle lever 54 contacts the tip of the screw 58 for setting. The rotation is regulated by. The rotation amount of the throttle lever 54 can be adjusted by moving against the spring 59 by the rotation of the setting screw 58, and the high idle rotation speed can be set to a predetermined rotation speed.
[0018]
An electrical component 60 for oil level warning is attached to the lower part of the mounting bracket 42, and an oil level warning light 61 is attached to the lower part. Further, an engine stop switch 62 is attached to the center of the mounting bracket 42. The engine stop switch 62 is turned on during operation and turned off to stop the engine. As described above, by mounting the oil level warning electrical component 60, the oil level warning light 61, and the engine stop switch 62 collectively on the mounting bracket 42, the lead wires connecting these components are shortened, and the wiring is easy.
[0019]
As shown in FIG. 8, the crankcase 3 that can be divided in the crankshaft direction is fastened and fixed to the crankcase 2 by bolts 70, and the crankcase 3 is an auxiliary output shaft to be described later to which power is transmitted from the crankshaft 6. The boss 82 has a boss 3a at one end thereof, and a seal 3b surrounding the crankshaft 6 and the boss 3a.
[0020]
As described above, the crankcase 3 having the boss portion 3a, the crankshaft 6, and the seal portion 3b surrounding the boss portion 3a allows the raw material to be divided in the crankshaft direction, and the raw crankcase 3 or the boss Power is taken out of the crankcase 3 by cutting at least one of the part 3a and the seal part 3b through the crankshaft 6.
[0021]
Next, a general-purpose engine that transmits power from the crankshaft to the auxiliary output shaft and extracts the power from the auxiliary output shaft will be described. 14 is a front view of the general-purpose engine, FIG. 15 is a right side view of the general-purpose engine, FIG. 16 is a diagram showing a power transmission mechanism from the crankshaft to the auxiliary output shaft, and FIG. 17 is a cross section taken along line XVII-XVII of FIG. FIG.
[0022]
In the general-purpose engine 1 of this embodiment, components having the same configurations as those of the general-purpose engine for directly extracting power from the crankshaft shown in FIGS. 1 to 13 are denoted by the same reference numerals, and description thereof will be omitted.
[0023]
The material of the crankcase 3 is configured in the same manner as in the above embodiment. At least the boss portion of the boss portion 3a and the seal portion 3b of the material of the crankcase 3 is cut, and the lid 80 is joined to the seal portion 3b. The lid 80 is fastened and fixed to the crankcase 3 with bolts 81. The auxiliary output shaft 82 penetrating the lid 80 is rotatably supported by the lid 80 via a bearing 83, and a seal 84 is provided outside the bearing 83. One end 82 a of the auxiliary output shaft 82 is rotatably supported by the boss 3 a of the crankcase 3. A sprocket 84 is integrally provided on the auxiliary output shaft 82, and a sprocket 86 is also fixed to the end 6a of the crankshaft 6 via a key 87. A chain 88 is wound around the sprockets 84 and 86, The power is transmitted from the shaft 6 to the auxiliary output shaft 82, and the power is taken out from the lid 80 through the auxiliary output shaft 82. At the tip of the auxiliary output shaft 82, there is formed a key groove 85 in which a fixing key (not shown) such as a pulley fixed to transmit power from the auxiliary output shaft 82 is mounted.
[0024]
As described above, the boss portion 3a that supports one end of the auxiliary output shaft 82 to which power is transmitted from the crankshaft 6 and the seal portion 3b that surrounds the crankshaft 6 and the boss portion 3a are cut into the crankcase 3. At least the material of the crankcase 3 can be used for both the method of directly extracting power from the crankshaft 6 and the method of extracting power from the auxiliary output shaft 82.
[0025]
【The invention's effect】
As described above, according to the first aspect of the present invention, the crankcase is formed with the boss portion supporting one end of the auxiliary output shaft to which power is transmitted from the crankshaft, and the seal portion surrounding the crankshaft and the boss portion. Despite the difference in the method of extracting power between the method of directly extracting power from the crankshaft and the method of extracting power from the auxiliary output shaft, it is possible to use at least the material of the crankcase and reduce costs, And quality control is easy.
[Brief description of the drawings]
FIG. 1 is a front view of a general-purpose engine.
FIG. 2 is a plan view of a general-purpose engine.
FIG. 3 is a rear view of the general-purpose engine.
FIG. 4 is a right side view of the general-purpose engine.
FIG. 5 is a left side view of the general-purpose engine.
FIG. 6 is a rear view in which a fuel tank of the general-purpose engine is removed and a part is cut away.
FIG. 7 is a sectional view of the general-purpose engine in a cylinder axial direction.
FIG. 8 is a sectional view of a general-purpose engine in a crankshaft direction.
FIG. 9 is a sectional view taken along the line IX-IX of FIG. 7;
FIG. 10 is a plan view of a cylinder head and an air shroud incorporating a valve operating mechanism.
FIG. 11 is a plan view of a throttle lever adjustment mechanism.
FIG. 12 is a side view of a throttle lever adjustment mechanism.
FIG. 13 is a sectional view taken along the line XIII-XIII in FIG. 11;
FIG. 14 is a front view of a general-purpose engine.
FIG. 15 is a right side view of the general-purpose engine.
FIG. 16 is a diagram showing a power transmission mechanism from a crankshaft to an auxiliary output shaft.
FIG. 17 is a sectional view taken along the line XVII-XVII in FIG. 16;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 General-purpose engine 2, 3 Crankcase 3a Boss part 3b Seal part 6 Crankshaft

Claims (1)

A crankcase that supports a crankshaft can be divided in the crankshaft direction, the crankshaft penetrates from the crankcase, and one end of the crankshaft protrudes from an outer surface of the crankcase. In general-purpose engines that take power directly from one end,
When the power of the crankshaft is taken out from the outer surface of the crankcase via an auxiliary output shaft,
A boss portion that supports one end of the auxiliary output shaft, and a seal portion that joins a lid that supports the other end of the auxiliary output shaft, on the side that takes out the power of the crankshaft via the auxiliary output shaft, The general-purpose engine is formed on an outer surface on the same side of the crankcase, and the seal surrounds the crankshaft and the boss.

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