JPH0640909Y2 - Two-cycle engine reciprocating power output device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an output device for extracting reciprocating power from engine power, and more specifically, omits a coupling, a belt and the like to obtain reciprocating power directly from a crankshaft. Can 2
The present invention relates to a reciprocating power output device for a cycle engine.

[Conventional technology]

In pesticide sprayers, washing machines, etc., it is necessary to drive working machines such as reciprocating pumps by an engine.

4 and 5 are structural diagrams of series-type and parallel-type reciprocating power output devices for driving a working machine such as a reciprocating pump by an engine.

In the series type reciprocating power output device of FIG.
And the working machine 12 are arranged such that their crankshafts 14 and 16 are coaxially arranged, and the crankshafts 14 and 16 are respectively ball bearings 1.
It is rotatably supported by crankcases 22 and 24 by 8 and 20. The coupling 26 is arranged in the space of the joint portion between the crankcases 22 and 24, and integrally and rotationally couples the crankshafts 14 and 16. The crankshaft 14 is rotatably attached to a base end portion of a connecting rod 30 on a crankpin 28, and is driven by an engine piston via the connecting rod 30 to rotate.

In the parallel type reciprocating power output device of FIG. 5, the engine 10 and the working machine 12 are arranged such that their crankshafts 14 and 16 are parallel to each other, and the rotation of the crankshaft 14 is a belt.
It is transmitted to the crankshaft 16 via 32.

[Problems to be solved by the device]

In such a conventional reciprocating power output device, the crankcase 24 of the working machine 12 is provided separately from the crankcase 22 of the engine 10, and the coupling for power transmission from the crankshaft 14 to the crankshaft 16 is provided. 26 and belt 32 and their related parts are required, increasing the number of parts,
The production is complicated, and the lubricating oil must be secured in the crankcase 24 of the working machine 12, which makes maintenance difficult.

On the other hand, in Japanese Patent Application No. 61-107442 (not shown), a crankshaft is provided with a connecting rod for a working machine as well as a connecting rod for an engine, so that the crankshaft and the crankcase of the engine and the working machine are shared. However, in that case, the crankshaft and the crankcase are elongated in the axial direction of the crankshaft, and the crankshaft is easily bent, so that the strength of the crankshaft needs to be increased. An increase in the length of the crankshaft leads to an increase in the volume of the crankcase.
In the case of a cycle engine, since the fuel gas is introduced into the combustion chamber of the two-cycle engine through the inside of the crankcase, the increase in the volume of the crankcase causes the pressure drop of the fuel gas in the crankcase, that is, the two-cycle engine. This will cause a drop in output. Further, there is a drawback that the stroke of the reciprocating motion taken out through the connecting rod for the working machine is limited to be approximately equal to the stroke of the piston of the engine.

An object of the present invention is to improve the reciprocating power output device of Japanese Patent Application No. 61-107442 and to provide a reciprocating power output device for a two-cycle engine capable of directly extracting reciprocating power for a working machine from a crankshaft. Is.

[Means for Solving the Problems]

This invention relates to a reciprocating power output device having an eccentric cam integrally formed on a crankshaft of an engine and having a power take-out member for taking out reciprocating displacement in conjunction with the cam, wherein the crankshaft (44) is a crankshaft. The present invention proposes a reciprocating power output device for a two-cycle engine including a cam-shaped overhanging portion (52) that also serves as an arm (48) and a balance weight (50).

[Action]

The overhanging portion (52) of the engine crankshaft (44) rotates as the engine crankshaft (44) rotates. The overhang part (52) is provided with a crank arm (4
8) Acts as a balance weight (50) and rotates as a cam. Power output member (74,74a, 7
4b) is driven in the axial direction by the overhanging portion (52) as a cam and reciprocates.

〔Example〕

 The present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 is a structural diagram of a reciprocating power output device for a two-cycle engine having one power take-out rod 74. The two-cycle engine 40 has a crankshaft 44 supported by a crankcase 42 at the bottom. Crankshaft 44 is spindle 46
And a projecting portion 52 including a crank arm 48 and a balance weight 50 that project radially in opposite directions,
A crank pin 54 having an axis parallel to the axis of the main shaft 46 and fixed to crank arms 48, 48 at both ends. The main shaft 46 is rotatably supported by the crankcase 42 by ball bearings 56, 56, and oil seals 58, 5 are provided.
8 is a ball bearing 5 in the axial direction of the crankshaft 44.
It is fitted to the inner peripheral portion of the crankcase 42 at a position outside the 6,56 to prevent fuel gas from leaking to the outside of the crankcase 42. The connecting rod 60 is rotatably attached to the crank pin 54 at the base end portion, and is connected to the piston (not shown) of the two-cycle engine 40 at the upper end portion. The recoil starter 62 is a 2-cycle engine 40
It is provided with a knob 64 that is pulled to forcibly rotate the crank shaft 44 at the time of starting, and is joined adjacent to the crank case 42.

The overhang portion 52 has a peripheral portion formed in a predetermined contour and has a crank arm.
It is designed to function not only as a 48 and balance weight 50 but also as a cam. FIG. 2 is a front view of the overhanging portion 52, and the contour of the overhanging portion 52 is an ellipse whose major axis is the plane direction passing through the center lines of the main shaft 46 and the crank arm 48. In FIG. 2, the two-dot chain line shows the shape of the overhanging portion 52 of the crankshaft 44 of the general two-cycle engine 40, which is circular. In order to make the peripheral portion of the overhanging portion 52 have a predetermined hardness, the peripheral portion of the overhanging portion 52 is induction hardened, or the entire crankshaft 44 is carburized and quenched.

Returning to FIG. 1, the cylindrical projecting portion 66 is formed as a portion of the crankcase 42 projecting in a direction perpendicular to the axial direction of the crankshaft 44. The spring receiving cap 68 is joined to the opening side end of the protrusion 66 by a bolt 70 and a nut 72 so as to cover the opening side of the protrusion 66. The power take-out rod 74 is, for example, a piston rod of a reciprocating pump, a plunger, or the like, extends through the protrusion 66 and the spring receiving cap 68, and is axially displaceable via the bearing 76 to protrude the protrusion 66.
It is supported by the inner wall of the. The oil seal 78 has a protrusion 66.
Is fitted to the stepped portion of the inner wall of the crankcase 42 to prevent the fuel gas from leaking from the inside of the crankcase 42 against the sliding of the power take-out rod 74. The compression coil spring 80 is a rod for extracting power.
The power take-out rod 74 is fitted on the power take-out rod 74 and is contracted between the flange 82 of the power take-out rod 74 and the inner surface of the spring receiving cap 68 to urge the power take-out rod 74 toward the overhang portion 52. The base end portion of the power extraction rod 74 is held in contact with the peripheral portion of the overhanging portion 52 by the urging force from the compression coil spring 80.

With the operation of the two-cycle engine 40, the reciprocating motion of the piston of the two-cycle engine 40 is transmitted to the crank pin 54 of the crank shaft 44 via the connecting rod 60, and the crank shaft 44 rotates. The overhanging portion 52 acts as a crank arm 48 and a balance weight 50 as parts on the engine side and also rotates as a cam. The power take-out rod 74 slides on the peripheral portion of the overhanging portion 52 as the overhanging portion 52 rotates, while the proximal end portion is held in contact with the peripheral portion of the overhanging portion 52 by the compression coil spring 80. A driving force in a direction perpendicular to the axial direction of the crankshaft 44 is exerted from the peripheral portion of the overhanging portion 52 and reciprocates. The stroke of the reciprocating motion of the power take-off rod 74 is the difference between the major axis and the minor axis in the elliptical contour of the overhang portion 52 in FIG.

FIG. 3 shows a plurality of power take-out rods 74a and 74b 2
It is a structural diagram of the reciprocating power output device of the cycle engine.
The protruding portion 84 divides the two cylindrical space portions into the first
Like the projecting portion 66 in the figure, it is formed as a portion of the crankcase 42 that projects in a direction perpendicular to the axial direction of the crankshaft 44, and the opening side is closed and joined by a spring receiving cap 86. The power take-out rods 74a, 74b are provided corresponding to the respective overhanging portions 52 of the crankshaft 44, and are arranged in the respective cylindrical space portions of the projecting portion 84 so as to be displaceable in the axial direction. Since the power take-off rods 74a, 74b and related parts such as their seals, supports, and biases have the same structure as the power take-out rod 74 and its related parts shown in FIG.
Or, the description will be omitted by adding b. In this embodiment, the working machine can be used when reciprocating power such as a double reciprocating pump is applied.

In the illustrated embodiment, the power take-off rods 74, 74a, 74b are
The base end portion is in direct contact with the peripheral portion of the overhanging portion 52, but it is also possible to slide the peripheral portion of the power take-out rods 74, 74a, 74b via rollers or the like. Further, a groove is formed in the peripheral portion of the overhanging portion 52, and the base end portions of the power take-out rods 74, 74a, 74b are formed in a bulging shape, and are inserted into the groove, and the opening side of the groove is for taking out power. The rods 74, 74a, 74b are bulged inward so that the swollen ends do not come off, and the grooves are used to guide the swollen ends to reciprocate the power take-off rods 74, 74a, 74b. Good. In that case, the compression coil spring 80 and the like can be omitted.

[Effect of the Invention] As described above, according to the present invention, the crank arm of the engine crankshaft and the overhanging portion as the balance weight form a cam, and the power takeout member is driven by the overhanging portion as the cam to reciprocate. Make a move. As a result, the crankshaft of the working machine and the power transmission mechanism such as the coupling and the belt from the crankshaft of the two-cycle engine to the crankshaft of the working machine can be omitted, and
The two-cycle engine and the working machine can have the same crankcase, the number of parts can be reduced, the manufacturing can be simplified, and the cost can be reduced.

In the present invention, since the drive unit of the power take-off member is disposed in the crankcase of the two-cycle engine, the working machine crankcase is separated from the two-cycle engine crankcase. Since it is not necessary to secure lubricating oil in the crankcase, maintenance such as inspection and replacement of lubricating oil becomes easy.

The cam is not provided as an additional member to the crank arm and the balance weight for receiving power from the piston via the connecting rod on the crank shaft, but the overhanging portion forming the crank arm and the balance weight. Since the crankshaft and the crankcase of the two-cycle engine are prevented from being elongated in the axial direction of the crankshaft, the deflection of the crankshaft can be reduced.

Also, since the increase in the volume of the crankcase is suppressed,
It is possible to avoid a decrease in the pressure of the fuel gas in the crankcase of the two-cycle engine and prevent a decrease in the output of the two-cycle engine.

Since the overhang portion can set the contour by appropriately changing the maximum distance and the minimum distance from the center of rotation to the peripheral contour, the stroke of reciprocating motion taken out through the power take-out member is the stroke of the piston of the two-cycle engine. Can be set independently for.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention, FIG. 1 is a structural view of a reciprocating power output device of a two-cycle engine having one power take-out rod, and FIG. 2 is a front view of an overhang portion,
FIG. 3 is a structural diagram of a reciprocating power output device for a two-cycle engine having a plurality of power take-out rods, FIG. 4 and FIG.
FIG. 1 is a structural diagram of a conventional series-type and parallel-type reciprocating power output device. 44 …… Crankshaft (engine crankshaft), 48 …… Crank arm, 50 …… Balance weight, 52 …… Overhanging part,
74, 74a, 74b ...... Power take-out rod (power take-out member, rod).

Claims (3)

[Scope of utility model registration request] 1. A reciprocating power output device comprising an eccentric cam integrally formed on a crankshaft of an engine, and a power take-out member for taking out a reciprocating displacement in conjunction with the cam, wherein the crankshaft (44) is , The cam-shaped overhanging part (5) that doubles as the crank arm (48) and the balance weight (50)
A two-cycle engine reciprocating power output device equipped with 2). 2. The reciprocating power output member has rods (74, 7) that slide on the peripheral portion of the projecting portion (52) at the base end portion.
4a, 74b), 2 of claim 1 of the utility model registration claim
Reciprocating power output device for cycle engine. 3. A reciprocating power output device for a two-cycle engine according to claim 2, wherein the peripheral contour of the projecting portion (52) is an ellipse.