JP2002309971A - Throttle control mechanism of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a throttle control mechanism for a general purpose engine in which the system can be suitably changed to a mechanical type or an electronic type according to specifications. SOLUTION: This throttle control mechanism for the engine has a carburetor throttle lever 17 that can adjust throttle valve opening; a governor lever 20; a governor rod 18a connected to the carburetor throttle lever 17, and a governor rod connected to the governor lever 20 between the governor lever 20 and the carburetor throttle lever 17; and a control lever 23 interposed between the governor rod 18a and the governor rod and provided to be driver by a motor. When the control lever 23 and the governor rod 18a are connected without motor driving, the throttle control mechanism functions as a mechanical governor device, and when the control lever 23 is separated from the governor rod and driven by the motor, the throttle control mechanism functions as an electronic governor device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle control mechanism for an engine, and more particularly, to a throttle control mechanism for a general-purpose engine which can be appropriately set to be changed mechanically or electronically.

[0002]

2. Description of the Related Art Conventionally, a general-purpose engine used as a power source for a mower, a power sprayer, a generator, or the like has a mechanical throttle control mechanism as a throttle control mechanism in order to maintain a constant engine speed regardless of load fluctuations. And electronic governors (governors). In this governor device,
Among mechanical types, there is known a type in which an arm is rocked by centrifugal force using rotation of a crankshaft, and the movement is transmitted by a link mechanism to open and close a throttle valve. Further, as an electronic type, a type is known in which a throttle valve is driven by a motor and a control signal is transmitted to the motor in accordance with an engine load to open and close the throttle valve.

In this case, although the mechanical governor is inexpensive, a link mechanism needs to be provided around the engine, and the degree of freedom in design is small. In addition, the control accuracy is limited because a small operation of the arm is transmitted. On the other hand, the electronic governor has high control accuracy, few mechanical parts, and has a high degree of freedom in design, but the price increases accordingly. For this reason, in general-purpose engines, it is usual to consider which of the two governors is appropriate according to the required specifications and price range, etc., decide the governor method at the design stage, and commercialize it. is there.

[0004]

However, the selection of the conventional governor system is determined based on an alternative method, and it has been found that the other system is desirable only in the actual use stage. However, there has been a problem that the device itself has to be replaced or the device has to be used daringly, and the usability is not good. In particular, when further control accuracy is required for a device equipped with a mechanical governor, an electronic device must be purchased separately, which imposes a wasteful investment.

An object of the present invention is to provide a throttle control mechanism for an engine that can change the system appropriately to a mechanical system or an electronic system according to specifications.

[0006]

A throttle control mechanism for an engine according to the present invention is connected to a throttle valve and is attached to an engine body, the throttle lever being provided to adjust the opening of the throttle valve,
A governor lever that operates according to the engine speed, a first rod that is disposed between the governor lever and the throttle lever, and that is connected to the throttle lever;
A governor rod including a second rod connected to the governor lever; and a control lever interposed between the first rod and the second rod, the control lever being drivable by a motor. .

Further, in the engine throttle control mechanism according to the present invention, the mechanism is a mechanical governor that controls the throttle valve opening based on the operation of the governor lever based on the motor drive and the presence or absence of the second rod. A device and an electronic governor device that controls the throttle valve opening degree by the motor are provided so as to be selectively switchable. That is,
If the motor is not driven and the control lever is connected to the first and second rods, the throttle lever is driven by the governor lever, and the mechanism functions as a mechanical governor device. On the other hand, if the control lever and the second rod are separated and the control lever is driven by a motor, the throttle lever is driven by the motor, and the mechanism functions as an electronic governor device.

In the present invention, since a control lever which can be driven by a motor is provided between the throttle lever and the governor lever, the mechanism can be selectively used as a mechanical governor or an electronic governor depending on whether or not the motor is driven. It can be used. Therefore, the control method can be appropriately changed according to the specification, and the versatility of the engine can be improved.

[0009]

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

FIG. 1 is a front view of an engine generator to which an engine according to an embodiment of the present invention is applied, FIG. 2 is a plan view of the engine generator of FIG. 1, and FIG. 3 is a rear view thereof.

The engine generator 1 according to the present embodiment is
As shown in FIGS. 1 to 3, a power generation unit 5 in which an engine 3 as a drive source and a power generator 4 are integrated on a support frame 2 formed by bending a pipe into a rectangular frame shape is provided with a plurality of support pieces 6. Elastically supported. The engine generator 1 employs an inverter system as a control system, and an inverter unit 11 for generating voltage control is attached to the side of the power generation unit 5 (on the rear side in FIG. 3) (see FIG. 1). .

As shown in FIG. 1, a control panel 7 is provided on the front of the apparatus. The control panel 7 is provided with switches such as an engine switch and an auto throttle switch, and output terminals such as an AC power terminal and a DC power terminal. A recoil knob 8a for driving a recoil starter 8 (see FIG. 8) is provided below the control panel 7, and the engine 3 is started by pulling the same.

Above the power generation unit 5, a fuel tank 9 for storing fuel supplied to the engine 3 is provided. A fuel supply port is provided substantially at the center of the upper surface of the fuel tank 9, and a fuel cap 10 is attached to the fuel supply port 9 so that it can be opened and closed.

FIG. 4 is a front view of a power generation unit 5 used in the engine generator of FIG. 1, FIG. 5 is a plan view thereof, FIG. 6 is a right side view of FIG. FIG. 8 is a cross-sectional view taken along the line ZZ in FIG. 5.

The power generation unit 5 includes the engine 3 and the power generator 4.
And the recoil starter 8. As shown in FIGS. 5 and 6, an inverter unit 11 for controlling a power generation output from the power generator 4 and converting the power to an AC having a predetermined frequency is attached to a side of the power generation unit 5. The inverter unit 11 has a configuration in which an electronic board is housed in an aluminum case 71 and is directly fixed to an aluminum fan cover 53.

The engine 3 is an air-cooled single-cylinder OHV gasoline engine having a crankcase 31 and a cylinder 32 above the crankcase 31.
3 is attached. An ignition coil 37 integrated with a plug cap is attached to the cylinder 32. A carburetor 12 is provided on the intake side of the engine 3, and outside air is introduced into the carburetor 12 through an air cleaner 36, where a mixture with gasoline is produced and supplied to the engine 3. on the other hand,
A muffler 14 is connected to the exhaust side via an exhaust pipe 13. Exhaust from the engine 3 passes through the muffler 14 and is discharged from an exhaust port 15 provided on the left side of the apparatus in FIG.

The carburetor 12 is provided with a throttle valve 16 as shown in FIG. The throttle valve 16 is opened and closed by a cab throttle lever 17 provided above the carburetor 12. The cab throttle lever 17 has a governor rod (first rod)
One end of the engine 18a is attached, and the engine 3 is adjusted to a constant engine speed by a mechanical throttle control mechanism (governor) without being affected by load fluctuations.

That is, as shown in FIGS. 4 and 5, a governor shaft 19 is rotatably mounted on the crankcase 31, and a base end of a governor lever 20 is attached thereto. The governor lever 20 includes a tension coil spring 22 connected to a speed control lever 21.
The governor lever 20 is urged clockwise in FIG. 5 by the tension coil spring 22. One end of a governor rod (second rod) 18 b is attached to the distal end of the governor lever 20, and the other end of the governor rod 18 b is connected to the control lever 23. Control lever 23
Is the plate 2 attached to the upper part of the power generation unit 5
5 rotatably supported. Further, the control lever 23 has a cab throttle lever 17 at one end.
The other end side of the governor rod 18a connected to is attached. Therefore, when the governor lever 20 rotates about the governor shaft 19, the governor rod 18
b, the control lever 23 and the governor rod 18a are linked, and the cab throttle lever 17 is operated.

In this case, the governor shaft 19 is engaged with a governor sleeve that is slidably mounted in an axial direction on a shaft that is rotationally driven by a crankshaft 34 of the engine 3. A rotating body is fixed to the shaft, and a plurality of governor arms are rotatably mounted on the end surface of the shaft at a predetermined radius from the center of rotation. And
Each governor arm is integrally provided with a governor weight, and these constitute a mechanical governor mechanism.

When the load on the engine 3 is reduced, the engine speed, that is, the crankshaft 3 is reduced by the reduced load.
The number of revolutions of 4 tries to increase temporarily. However, the centrifugal force applied to the governor weight decreases as the rotation speed decreases, and the governor arm closes, whereby the governor sleeve moves and the governor shaft 19 rotates to the low speed side. And
The governor lever 20 also rotates together with the governor shaft 19,
The movement is transmitted to the cab throttle lever 17 via the governor rod 18a and the like, and the throttle valve 16 is driven in the closing direction. Thus, the engine speed is reduced according to the load. On the other hand, when the engine load becomes high, the governor lever 20
Is turned in the opposite direction. Therefore, the engine speed is adjusted to be constant without being affected by the load fluctuation.

On the other hand, in the engine generator 1, such a governor mechanism can be easily changed from a mechanical type to an electronic type. 9 and 10 are explanatory diagrams showing a state in which the throttle control mechanism is changed to an electronic governor. FIGS. 9 and 10 correspond to FIGS. 4 and 5, respectively.

As shown in FIG. 9, a stepping motor 24 is provided below the control lever 23 here. The stepping motor 24 is provided with a rotating shaft 24a facing upward, and the rotating shaft 24a is fixed to a boss shaft 23a of the control lever 23. That is, the control lever 23 is driven to rotate left and right about the boss shaft 23a by the stepping motor 24. In FIGS. 9 and 10, the governor rod 18b is removed.

The stepping motor 24 is controlled by an engine control unit (not shown).
The engine control unit constantly monitors the engine load.
4 to rotate the control lever 23 appropriately. As a result, the cab throttle lever 17 operates via the governor rod 18a, and the engine speed is adjusted to a constant value according to the load fluctuation.

In this case, the stepping motor 24 is mounted as follows. First, the governor rods 18a and 18b are removed from the control lever 23, and the control lever 23 is removed together with the plate 25. When the plate 25 is removed, the motor housing 26
Is provided. Then, the stepping motor 24 is stored in the motor accommodating portion 26 to perform a predetermined connection. After the connection is completed, the plate 25 is attached, and the control lever 23 is fixed to the rotating shaft 24a. Thereafter, only the governor rod 18a is attached to the control lever 23.
Thereby, the mechanical governor of FIG. 4 is replaced with an electronic governor. To replace the electronic governor with a mechanical governor, on the contrary, the stepping motor 24 may be removed and the governor rod 18b may be attached.

Thus, in the engine generator 1,
With a simple operation, the throttle control mechanism can be changed from mechanical to electronic or from electronic to mechanical. That is, the apparatuses shown in FIGS. 4 and 9 differ only in the presence / absence of the stepping motor 24 and the governor rod 18b, so that the control method can be changed very easily without major structural change. Therefore, the versatility of the engine can be improved, for example, the control method can be appropriately changed according to the specifications and price required as a product.

The engine 3 has a crankshaft 34 incorporated in the crankcase 31 so as to extend in the left-right direction in FIG. In the power generation unit 5, one end side of the crankshaft 34 is an output shaft of the engine 3, and a flywheel 51,
The cooling fan 52, the recoil starter 8, and the power generator 4 are arranged in this order. That is, the flywheel 51 and the cooling fan 52 are attached to the next position of the engine 3, and the adapter 5 fixed to the flywheel 51 is provided.
5, a recoil starter 8 and a power generator 4 are provided at the end thereof. Thus, when the power generator 4 and the recoil starter 8 are arranged on the same side, the crankshaft 34 can be shortened, and both the power generator 4 and the engine 3 can be cooled by one cooling fan 52. Become.

As shown in FIG. 8, one end 34a of the crankshaft 34 of the engine 3 is
1 and is supported by a bearing 35 mounted on the bearing 1.
The other end of the crankshaft 34 is also supported by a bearing (not shown) on the opposite side.
1 is freely rotatable. One end 34a protrudes out of the crankcase 31, and a flywheel 51 for stabilizing the engine output such as the rotation speed and torque of the engine 3 is attached to the one end 34a. Flywheel 51
Is composed of a boss portion 51a fixed to the crankshaft 34 via a key, and a disk portion 51b extending radially from the boss portion 51a.

A cooling fan 52 is attached to the disk section 51b. The cooling fan 52 is a disk unit 52
a and a number of fan blades 52b provided integrally on the surface of the disk portion 52a. Cooling fan 5
2 is covered by a fan cover 53 fixed to the engine 3. The fan cover 53 is made of aluminum, and has a number of slits 5 on the side surfaces serving as cooling air intakes.
4 are provided. The fan cover 53 also has a function as a duct for guiding air. As shown in FIG. 8, as the cooling fan 52 rotates, outside air is introduced into the fan cover 53 from the slit 54 and the cooling air Is sent to the engine 3 side and guided.

A recoil starter 8 is disposed next to the flywheel 51. The recoil ring 5 is attached to the boss 51 a of the flywheel 51 via an adapter 55.
6, a recoil holder 57 in which the disk portion 57a and the cylindrical portion 57b are integrated is provided at the next position. A recoil pulley 59 around which a recoil rope 58 is wound is rotatably mounted outside the cylindrical portion 57b.

The recoil pulley 59 is provided with an engagement claw (not shown). When the recoil knob 8 a is pulled and the recoil pulley 59 is rotated by the recoil rope 58, the engagement claw is engaged with the recoil ring 56. Accordingly, the crankshaft 34 connected via the adapter 55 rotates, and the engine 3 is started. The recoil holder 57 is provided with a rewind spring (not shown), and the recoil rope 58 is rewound onto the recoil pulley 59 by a spring force.

The power generator 4 is disposed next to the recoil starter 8. In the engine generator 1, the power generator 4
Is an inner rotor type, and is composed of an inner rotor 41 and a stator 42. Inner rotor 41
Is composed of a rotor shaft 43 and a rotor disk 45, and the rotor shaft 43 is fixed to the tip of the boss 55 a of the adapter 55 by a through bolt 60. In this case, a tapered portion 55b is formed in the boss portion 55a, and the tapered portion 55b is
Is fitted to the tapered hole 43a provided in the first hole. On the other hand, the other end of the rotor shaft 43 is rotatably supported by a bearing 61 attached to the power generator rear cover 44. A stator 42 is provided outside the inner rotor 41. In this case, the stator 42 is attached so as to be sandwiched between a fan cover 53 and a power generator rear cover 44.

A plurality of magnets (not shown) are mounted on the outer peripheral surface of the inner rotor 41 along the circumferential direction. On the other hand, the stator 42 is provided with a core 62 formed by laminating a number of steel plates, and a coil 63 is wound therearound. And the crankshaft 34
As the magnet of the inner rotor 41 rotates inside the coil 63 with the rotation of, an electromotive force is generated in the coil 63 to generate power.

The power generator rear cover 44 has a disk portion 44a in which a ventilation hole 64 is formed and a cylindrical portion 44b integrated with the disk portion 44a. The power generator rear cover 44 is fixed to the fan cover 53 at the cylindrical portion 44 b, and at this time, the stator 42 is held between the power cover and the fan cover 53. Then, as shown in FIG. 8, with the rotation of the cooling fan 52, outside air is introduced into the power generator rear cover 44 from the ventilation holes 64, and flows toward the engine 3 while cooling the stator 42 and the like.

On the other hand, outside air also flows into the power generation unit 5 from a slit 54 formed on the side of the fan cover 53. This airflow is joined with the cooling air introduced from the ventilation holes 64 and cooling the stator 42 and the like, guided by the fan cover 53 and blown around the engine 3.
That is, the cooling fan 52 generates two types of cooling air, the slit 54 and the ventilation hole 64, thereby cooling both the power generator 4 and the engine 3. Then, the cooling air blown to the engine 3 goes behind the engine 3 to cool the muffler 14.

The present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the scope of the invention.

[0036]

According to the present invention, since a control lever which can be driven by a motor is provided between the throttle lever and the governor lever, the mechanism can be selectively used as a mechanical governor or an electronic governor depending on whether or not the motor is driven. It can be used. Therefore, the control method can be appropriately changed according to the specification, and the versatility of the engine can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of an engine generator to which an engine according to an embodiment of the present invention is applied.

FIG. 2 is a plan view of the engine generator of FIG. 1;

FIG. 3 is a rear view of the engine generator shown in FIG. 1;

FIG. 4 is a front view of a power generation unit used in the engine generator of FIG.

FIG. 5 is a plan view of the power generation unit of FIG.

6 is a right side view of FIG. 5 (in the X direction shown by an arrow).

FIG. 7 is a left side view of FIG. 4 (Y direction indicated by an arrow).

FIG. 8 is a sectional view taken along the line ZZ in FIG. 5;

FIG. 9 is a front view of the power generation unit in a state where the throttle control mechanism is changed to an electronic governor.

FIG. 10 is a plan view showing the power generation unit in a state where the throttle control mechanism is changed to an electronic governor.

[Explanation of symbols]

 3 Engine 16 Throttle valve 17 Cab throttle lever 18a Governor rod (first rod) 18b Governor rod (second rod) 20 Governor lever 23 Control lever 24 Stepping motor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G065 BA02 BA04 DA06 DA08 DA14 EA10 GA10 GA36 GA41 KA05 KA11 KA32 KA33

Claims (2)

[Claims] 1. A throttle lever connected to a throttle valve and provided so as to adjust the opening of the throttle valve, a governor lever attached to an engine body, and operated according to the engine speed, the governor lever and the throttle A governor rod that is provided between the first rod and the second rod and that is connected to the throttle lever and that is connected to the governor lever; And a control lever provided so as to be driven by a motor. 2. The throttle control mechanism for an engine according to claim 1, wherein the mechanism controls the throttle valve opening based on the operation of the governor lever based on the driving of the motor and the presence or absence of the second rod. And an electronic governor device that controls the throttle valve opening degree by the motor so as to be selectively switchable.