JP3109213B2 - Governor lever rotation mechanism for general-purpose engine governor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a governor device in a general-purpose engine for maintaining a rotation speed of a crankshaft at a constant rotation speed, in which a governor lever is rotated in accordance with a change in the rotation speed of the crankshaft. It relates to improvement of the mechanism.

[0002]

2. Description of the Related Art A general-purpose engine is provided with a governor device for maintaining a constant rotation speed of a crankshaft regardless of the magnitude of a load. In other words, in this governor device, the throttle valve of the carburetor is linked to the governor lever that rotates according to the rotation speed of the crankshaft, and when the load on the general-purpose engine increases and the rotation speed of the crankshaft decreases, the throttle valve opens. Conversely, when the load decreases and the crankshaft speed increases, the throttle valve closes and the speed decreases,
The rotation speed of the crankshaft is adjusted to a fixed set rotation speed.

A governor lever rotating mechanism for rotating the governor lever is provided in a crankcase of an engine, and includes a governor shaft 1, a governor gear 2, a governor weight 3, and a governor slider 4, as shown in FIG. Is done. The governor gear 2 is loosely fitted to the governor shaft 1 and rotates synchronously with a crankshaft (not shown). The governor weight 3 is pivotally supported on the bottom surface of the inner wall of the governor gear 2 using a pin 5. The governor slider 4 is slidably disposed on the governor shaft 1, abuts against the arm 6 of the governor weight 3, and is slid by the action of the arm 6.

[0004] A governor lever 7 for opening and closing a throttle valve (not shown) contacts the governor slider 4 via a return shaft 8 and rotates according to the sliding stroke of the governor slider 4 to adjust the opening of the throttle valve. I do.

Usually, when the load increases while the crankshaft of the engine is rotating at the set speed, the speed of the crankshaft decreases. At this time, the centrifugal force acting on the governor weight 3 also decreases, so that the governor weight 3 turns toward the governor shaft 1 (in the direction of the arrow N in FIG. 6) and contracts. As a result, the arm 6 of the governor weight 3 approaches the bottom surface of the inner wall of the governor gear 2, the governor slider 4 is retracted, and the governor lever 7 pivots in a direction to fully open the throttle valve (the direction of arrow M in FIG. 6).
The crankshaft rises to the set speed.

[0006]

Conventionally, the throttle valve is fully opened at the position where the governor slider 4 is fully retracted, and at this time, the governor slider 4 is
Is set to be placed on the arm part 6 of the first section.

However, the backlash between the pin 5 and the governor weight 3 causes the governor slider 4 to be retracted most, that is, in the region where the stroke of the governor slider 4 shown in FIG. An excessive load acts on the slider 4, and the slider load F acting on the governor lever 4 from the governor slider 4 increases rapidly. When the stroke of the governor slider 4 is inevitably reduced due to the layout of the engine,
The sudden increase of the slider load F in a small stroke may adversely affect the performance of the governor device. For example, when the load suddenly increases during the operation of the engine, there is a possibility that the opening time of the throttle valve becomes insufficient and the rise time becomes longer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a slider load characteristic of a governor lever rotating mechanism, whereby the governor lever rotation of a general-purpose engine governor can be improved. The purpose is to provide a mechanism.

[0009]

SUMMARY OF THE INVENTION The present invention provides a governor gear which is loosely fitted to a governor shaft and rotates synchronously with a crankshaft, and is provided on a side surface of the governor gear so as to be expandable and contractable by the action of centrifugal force. A governor weight having an arm portion, and a governor slider slidably mounted on the governor shaft, abutting on the arm portion and sliding by the action of the arm portion, and operatively attached to the governor slider. In a governor lever rotating mechanism of a general-purpose engine governor device that adjusts an opening degree of a throttle valve by rotating a connected governor lever, in the governor shaft, a shim is interposed between a side surface of the governor gear and the governor slider, Cleared between the governor weight arm and the governor slider with the governor weight in the minimum diameter state Nsu are those that have been set.

[0010]

Therefore, according to the governor lever rotating mechanism of the general-purpose engine governor device according to the present invention, the clearance is set between the governor weight arm and the governor slider in the state where the governor weight is in the minimum diameter state. When the governor weight is approaching the minimum diameter state and the stroke of the governor slider is reduced due to a decrease in the rotation speed of the shaft, the excessive load generated on the governor weight is prevented from acting on the governor slider via its arm. it can. As a result, the slider load characteristics of the governor slider are optimized, and the performance of the governor device can be improved.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a governor lever rotating mechanism of a general-purpose engine governor device according to the present invention. FIG. 2 is a right side view, partially cut away, of a general-purpose engine to which the governor lever rotating mechanism of FIG. 1 is applied.

As shown in FIGS. 2 and 3, a general-purpose engine 10 includes a crankcase 11 and a cylinder assembly 1.
2. Main components such as a carburetor 13, an air cleaner 14, a fuel tank 15, a muffler 16, and a recoil starter 17 are arranged adjacent to each other in a rectangular space. The crankcase 11 and the cylinder assembly 12 constitute an engine 18 in a narrow sense, and the cylinder assembly 1
2 is installed diagonally above the crankcase 11. The engine 18 in a narrow sense is, for example, a single-cylinder four-cycle engine and includes an OHV type valve operating mechanism 19.

The recoil starter 17 is installed on the left side of the crankcase 11 of the engine 18 and starts the engine 18 by forcibly rotating the crankshaft 20 in the crankcase 11 when the engine 18 starts.
Also, the air cleaner 14 and the fuel tank 15
Is disposed above the crankcase 11. The carburetor 13 is located on the left side of the cylinder assembly 12 of the engine 18 and is provided with the cylinder assembly 1.
2 is connected. This carburetor 13 has an air cleaner 1
4 and the fuel tank 15 are connected, and the air-fuel mixture is supplied to the engine 18. Further, the muffler 16 is connected to the cylinder assembly 12 of the engine 18 via an exhaust pipe 21 to discharge waste gas from the engine 18. This muffler 16 is a cylinder assembly 1
2 above.

The crankshaft 20 is supported in the crankcase 11 in the left-right direction. On the other hand, a crankcase cover 22 is detachably provided on the right side surface of the crankcase 11. One end of the crankshaft 20 protrudes from the crankcase cover 22 and extends. A working machine (not shown) such as a generator or a pump is connected to the protruding portion of the crankshaft 20 to extract power of the general-purpose engine 10.

The above-described general-purpose engine 10 is provided with a governor device 23 that always keeps the rotation speed of the crankshaft 20 at a set rotation speed even when the load varies. The governor device 23 includes a governor lever 24, a governor lever rotating mechanism 25, and an auto idle solenoid 26.

The governor lever 24 is connected to the crankcase 11
And the fuel tank 15, and is rotatably supported by the crankcase 11 by a return shaft 27. The tip of the governor lever 24 is a governor rod 28
Is connected to the throttle valve 29 of the carburetor 13, and the opening of the throttle valve 29 is determined according to the rotation of the governor lever 24. The distal end of the governor lever 24 is further connected to an opening setting lever 31 via a governor spring 30. This opening degree setting lever 31 is
It is rotatably disposed on the cylinder assembly 12 of the engine 18 in a narrow sense. The governor spring 30 applies an urging force to the governor lever 24 so as to rotate the governor lever 24 in a direction in which the throttle valve 29 opens.

The governor lever rotating mechanism 25 is
As shown in FIGS. 1, 3 and 4, the return shaft 27, governor shaft 32, governor gear 33, governor weight 34 and governor slider 35 are provided. The governor shaft 32 is connected to the crankshaft 20.
And is fixed in the crankcase cover 22 in parallel with the crankcase 11.

The governor gear 33 has a cup shape, and a gear portion 33a is formed on the outer periphery near the opening end. The gear portion 33 a meshes with a fixed gear 36 fixed to the crankshaft 20, and the governor gear 33 rotates synchronously with the crankshaft 20.

The governor weight 34 has a weight portion 34a and an arm portion 34b provided in an L-shape in a side view. The governor weight 34 is pivotally supported on the inner wall bottom surface 37 of the governor gear 33 by using a pin 38. The pin 38 is located at the central position of the governor weight 34 in an L-shape in side view. Therefore, the governor weight 34
Is configured to be able to expand and contract around the pin 38 by the action of centrifugal force generated in the weight portion 34 a by the rotation of the governor gear 33.

The governor slider 35 is mounted on the governor shaft 3.
2 is slidably fitted to the base member, and a slider flange 35 is provided at the base end.
a. The slider flange 3 of the governor slider 35
5a is provided so as to be able to abut on the arm portion 34b of the governor weight 34, and the governor slider 35 is configured to be able to be pushed or retracted when the governor weight 34 is expanded or contracted. The shaft operating portion 27b of the return shaft 27 is in contact with the tip of the governor slider 35.

As shown in FIG. 2, the return shaft 27 is disposed on the upper surface of the crankcase 11 so as to protrude vertically and to be rotatable, and the governor lever 24 is fixed to the upper end. The lower end of the return shaft 27 is curved and extends horizontally, and the horizontally extended portion is the shaft operating portion 27a. The return shaft 27 rotates in response to the pushing or pulling operation of the governor slider 35, whereby the governor lever 24 is rotated in the direction of arrow A or the direction of arrow B in FIG.

The rotation speed of the general-purpose engine 10 is set by operating the rotation speed setting lever 31 to operate the governor spring 30.
Is adjusted to determine the opening of the throttle valve 29, and the rotation speed setting lever 31 is set to the thumbscrew 39.
It is carried out by fixing with. This rotation speed is, for example, 2000 rpm and 2500 rpm as shown in FIG.
.., 4000 rpm.

When the load acting on the crankshaft 20 decreases during operation of the general-purpose engine 10 and the rotation speed of the crankshaft 20 rises above a set rotation speed, as shown in FIG. 3
The fourth weight portion 34a rotates in the centrifugal direction, and the governor weight 34 expands in diameter. The arm portion 34b of the governor weight 34 presses the governor slider 35. Then, the governor slider 35 is pushed out to rotate the return shaft 27, and the governor lever 24 pivots in the direction A (FIG. 4) to close the throttle valve 29, and lowers the rotational speed of the general-purpose engine 10 to the set rotational speed. Hold.

Conversely, when the load increases and the rotation speed of the crankshaft 20 falls below the set rotation speed, the centrifugal force acting on the weight portion 34a of the governor weight 34 decreases, and the weight portion 34a Then, the governor weight 34 is reduced in diameter. Then, the governor lever 24 is acted on by the biasing force of the governor spring 30,
By rotating the throttle valve 29 in the opening direction B (FIG. 4), the rotation speed of the general-purpose engine 10 is increased and maintained at the set rotation speed.

On the other hand, the auto idle solenoid 26
Is the solenoid mounting bracket 4 attached to the crankcase 11.
0, and the solenoid operating portion 26 a is connected to the longitudinal center of the governor lever 24. When no load is applied during operation of the general-purpose engine 10, the auto idle solenoid 26 electrically detects, for example, this no-load state, and moves the governor lever 24 in the direction of arrow A against the urging force of the governor spring 30. Referring to FIG. 4, the throttle valve 29 is closed to put the general-purpose engine 10 in an idling state to reduce engine noise and save fuel.

Further, in the governor lever rotating mechanism 25 in the above embodiment, as shown in FIG. 1, a shim 41 is interposed between the slider flange 35a of the governor slider 35 and the inner wall bottom surface 37 of the governor gear 33. The shim 41 is fitted on the governor shaft 32. The governor weight 34 is reduced in diameter by the interposition of the shim 41, and the upper end of the arm 34b and the slider flange of the governor slider 35 are in a state where the bottom of the arm 34b is in contact with the bottom 37 of the inner wall of the governor gear 33. A clearance L is set between the portion and the portion 35a. By setting the clearance L, contact between the arm portion 34b of the governor weight 34 and the slider flange 35a of the governor slider 35 is prevented in a region where the governor slider 35 has a small stroke.

Generally, near the minimum diameter state of the governor weight 34, the load acting on the governor slider 35 from the governor weight 34 becomes excessive due to backlash between the pin 38 and the governor weight 34. In the small slide stroke region, the shaft operating portion 2 of the return shaft 27 from the governor slider 35
The slider load F acting on 7a becomes excessive as shown in FIG. However, if the clearance L is set as described above, the arm portion 34 of the governor weight 34 in a region where the stroke of the governor slider 35 is small.
Since b does not contact the slider flange 35a of the governor slider 35, an excessive load generated on the governor weight 34 due to rattling between the pin 38 and the governor weight 34 is not transmitted to the governor slider 35, and the slider load F exhibits an appropriate characteristic of smoothly increasing in the slider stroke region equal to or greater than the clearance L. For this reason, the performance of the governor device 23 is improved.
When the load suddenly increases during the operation of the
Slider load F acting on return shaft 27 from No. 5
Of the carburetor 13
9 can be quickly increased, and the number of revolutions of the crankshaft 20 can be smoothly increased.

Also, by changing the thickness of the shim 41, the load range acting on the governor slider 34 from the governor weight 34 can be changed.
Can be easily changed and set. Therefore, other general-purpose engines 10 having different slider loads F can be handled only by changing the thickness of the shim 41, and components other than the shim 41 of the governor lever rotating mechanism 25 can be shared.

[0030]

As described above, according to the governor lever rotating mechanism of the general-purpose engine governor device of the present invention, the governor shaft is provided with the shim between the side surface of the governor gear and the governor slider. Since a clearance is set between the arm portion of the governor weight and the governor slider in the minimum diameter state, an excessive load generated on the governor weight when the slider stroke of the governor slider is small does not act on the governor slider. , The slider load characteristics of the governor slider can be optimized,
As a result, the performance of the governor device can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a governor lever rotating mechanism of a general-purpose engine governor device according to the present invention.

2 is a right side view of the general-purpose engine to which the governor lever rotation mechanism of FIG.

FIG. 3 is a plan view showing a part of the general-purpose engine shown in FIG.

FIG. 4 is a partially enlarged view of FIG. 3;

FIG. 5 is a graph showing slider load characteristics in the governor lever rotating mechanism of FIG. 1;

FIG. 6 is a sectional view showing a conventional governor lever rotating mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 General-purpose engine 13 Carburetor 20 Crankshaft 23 Governor device 24 Governor lever 25 Governor lever rotation mechanism 27 Return shaft 28 Governor rod 29 Throttle valve 30 Governor spring 31 Speed setting lever 32 Governor shaft 33 Governor gear 34 Governor weight 34b Armer slider Tsubabe 41 Shim L Clearance

Claims (1)

(57) [Claims] 1. A governor gear which is loosely fitted to a governor shaft and rotates synchronously with a crankshaft, and a governor weight which is pivotally supported on a side surface of the governor gear and is provided so as to be able to expand and contract by a centrifugal force and has an arm portion. A governor slider slidably disposed on the governor shaft, abutting against the arm portion, and sliding by the action of the arm portion, and having a governor lever operatively connected to the governor slider. In the governor lever rotating mechanism of the general-purpose engine governor device for adjusting the opening degree of the throttle valve, a shim is interposed between the governor gear side surface and the governor slider on the governor shaft, and the governor weight is in the most reduced state. The clearance is set between the governor weight arm and the governor slider. The governor lever rotation mechanism of the general-purpose engine governor device.