JPH02163427A - Throttle device for internal combustion engine - Google Patents

Abstract

PURPOSE:To permit the stable throttle operation by opening an engine throttle valve from the idling opening degree to the intermediate opening degree by the operation of the second lever and opening the throttle valve from the intermediate opening degree to the perfect opening degree by the operation of the first lever. CONSTITUTION:When neither the first nor the second levers 4 and 5 of a throttle device 2 is operated, and internal combustion engine is in idling state. When a lever 5 is grip-tightened from the position D to the position E corresponding to the prescribed intermediate opening degree of a throttle valve, said movement is transmitted to the first lever 4 through a cam follower 13 and a cam surface 9, and the lever 4 is interlocked with the lever 5 and pivotally moved to the intermediate opening degree position B, and the internal combustion engine is accelerated to the intermediate speed. When the engine speed is increased to the max. speed, the lever 4 is throttled to the perfect opening degree position C. At this time, the cam follower element 13 is separated from the cam surface 9, and the lever 5 does not shift. When the idling state is generated again, a hand is separated from the levers 4 and 5, and then the return to the opening degree position A, D is performed by a spring. Therefore, the throttle device having the simple structure and convenience for use can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a throttle device for an internal combustion engine, and more particularly to a throttle device for an internal combustion engine used in a portable working machine such as a brush cutter.

2. Description of the Related Art A throttle device for controlling the opening degree of a throttle valve of an internal combustion engine as a power source for a portable working machine as described above usually has a throttle lever pivotally attached to a handle or an operating stick, and the operating name is Operate the throttle lever with the fingers of the hand holding the handle or control stick, adjust the opening of the throttle valve, and output RrlJ! II tit. In general, internal combustion engines are often operated by maintaining the throttle valve in an intermediate state between idling and full throttle, especially in working machines such as brush cutters (1'f negative In such machines, the throttle valve of the internal combustion engine is often used in an intermediate state of f7t1m due to vibration and noise problems and fuel economy.

However, with conventional throttle devices, it is difficult for the operator to stably maintain the throttle lever at an intermediate opening position with his or her fingers, and the hand gets tired if the throttle lever is pulled for a long time. With the type, there is no problem like the one mentioned above during normal work, but the throttle lever does not return to the idling position just by releasing the hand, and the centrifugal clutch does not disengage, causing the mower, etc. to operate. Sustaining had drawbacks such as being dangerous to work with.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to eliminate the drawbacks of the prior art, and to provide a throttle device for an internal combustion engine that is simple in structure and convenient to use.

Means for Solving the Problems 11 A throttle device for an internal combustion engine according to the present invention includes a main body and a main body that is sunk in the main body so as to be pivotable between an idling opening position and a fully open opening position. a first lever operatively connected to a throttle valve of the internal combustion engine; a second lever mounted on the body for pivoting between an idle position and an intermediate position; The pivoting motion of the second lever between the idling opening position δ and the intermediate opening position is transmitted to the first lever, and the C1i#i first lever is moved between the idling opening position d and the intermediate opening position. and spring means for returning the first and second levers to idling opening positions.

Operation Therefore, by operating the second lever, the line throttle valve can be opened from the idle link of 8 degrees to a predetermined intermediate opening, and if necessary, the first lever can be operated to open the throttle piece to the intermediate opening. When the first and second levers are further released, the throttle valve can automatically return to the idle link opening position.

Example Next, the present invention will be explained based on the embodiments shown in the drawings.

First, in the first embodiment shown in FIGS. 1 to 3, a throttle device 2 according to the present invention is fixed to the tip of a hollow tubular handle 1, and the throttle device H2 is attached to a hollow main body 3. A first lever 4 is pivotally mounted on one side, and a second lever 5 is pivotally mounted on the opposite side of the main body 3 from the first lever 4. Said first
The lever 4 carries a wire 6 at its inner end within said body 3, said wire 6 being operatively connected to a throttle valve (not shown) of the carburetor of the associated internal combustion engine. 1, the first lever 4 is released and biased outward from the main body 3 by the spring means of the biasing spring 7 to the outer position shown in FIG. 1, that is, the idling opening position. ra, the throttle valve is maintained in the idle link opening state, and the first lever 4 is pivoted to the intermediate opening position (17'tB, that is, a predetermined intermediate opening position B) shown in FIG. 2, as will be described later. When the throttle valve is opened in normal use, the throttle valve is held in a predetermined intermediate opening state against a return spring (not shown), and the first lever 4 is in the inward position shown in FIG. hearsay 17
When further pivoted to i11 position C, the throttle valve is maintained in the fully open state. Furthermore, the first
The lever 4 has a through hole 8 formed in its middle portion, and the through hole 8 defines a cam surface 9.

In some cases, it is also possible to omit the bias spring 7 and use only the return spring (not shown) of the throttle valve of the carburetor as the spring means.

On the other hand, the second lever 5 is provided with an adjusting screw 11 that is screwed in the distal end thereof in the lateral direction and is biased outwardly by a compression spring 10 for holding the position. , a rod-shaped member 1 extending from its tip into the inside of the main body 3
2 is fixed.

The bent tip of the rod member 12 engages with the cam surface 9 of the first lever 4, forming a cam follower 13 that cooperates with the cam surface 9.

When the second lever 51 is released, it is at the outer position shown in FIG. 1, that is, at the idling opening position 1ffD.

Therefore, when the operator controls the first and second throttle device 2,
When neither of the levers 4 and 5 is operated, the internal combustion engine is maintained in an idle state. In this state, the operator moves the second lever 5 from the position shown in FIG. 1 with the palm of the hand that is gripping the handle 1 from the inward position mark shown in FIG. 2 to a predetermined intermediate opening of the throttle valve. When tightened to a corresponding degree to HE, the movement of this second lever 5 is caused by the cam follower 1111
'13 and the cam surface 9 to the first lever 4, whereby the first lever 4 is pivoted in conjunction with the second lever 5 to the intermediate opening position B in FIG. The engine is sped up to its predetermined intermediate speed. When it is desired to further increase the engine speed to the maximum speed, the operator uses his index finger or the like to squeeze the first lever 4 to the fully open position C in FIG.

At this time, the cam follower 13 at the tip of the rod-shaped member 12 separates from the cam surface 9 of the through hole 8, so the second lever 5 moves to the second position.
It remains stopped at ffE as shown in the figure and does not move. When returning the internal combustion engine to the idle state, the first and second levers 4
and 5, these levers 4.5 automatically return to their respective idling opening positions IA and D (not shown in FIG. 1) by means of spring means. The adjustment screw 11 is operated when adjusting the setting of the predetermined intermediate opening position of the second lever 5.

Next, the throttle device 14 of the second embodiment of the present invention shown in FIGS. 4 to 6 has a first lever 16 and a second lever 17 on its main body 15 coaxially and independently of each other. The adjustment screw 18 loosely fits into and passes through a hole 19 formed in the second lever 17 and is screwed into a screw hole 20 formed in the first lever 16. ing. Furthermore, a compression coil spring 21 acting between the first and second levers 16 and 17 is arranged around the adjusting screw 18, and the spring 21 is connected to the head of the 51 setting screw 18 and the second The lever 17 acts to bias the two levers so that they come into contact with each other.

With this configuration, when accelerating the internal combustion engine, the second lever 17 is moved from the idling opening position shown in FIG. 4 to the predetermined intermediate opening position shown in FIG. 5 using the operator's middle and ring fingers. Pivot to ME. This pivoting motion is transmitted to the first lever 16 via the adjusting screw 18, whereby the first lever 16 moves in conjunction with the second lever 17 from the idling opening position A of FIG. 4 to the position of FIG. The throttle valve of the internal combustion engine is pivoted to the intermediate opening position B, and the throttle valve of the internal combustion engine is maintained at the predetermined intermediate opening position through the wire 22. When the engine speed is further accelerated, the first
Move the lever 16 to the intermediate amount F! in FIG. Pivot from position B to fully open position C in FIG. 6 using your index finger or the like. This pivoting is in the direction in which the head of the adjustment screw 18 moves away from the second lever 17, so no rotational force is transmitted to the second lever 17, and the second lever 17 moves to its intermediate opening position HE. will be maintained. When the engine speed is returned to the idle link speed, if the first and second levers 16 and 17 are released, the first and second levers 16 and 17 are released.
The levers 16 and 17 of the spring 2 act on the first lever.
1 and the fourth by a throttle valve return spring (not shown).
Idling open rI in the figure; automatically returns to 1 position A and D, respectively.

Next, the throttle device 23 of the third embodiment of the present invention shown in FIGS. 7 to 9 has first and second levers 25 and 26 coaxially and independently pivoted on its main body 24. Although it is movably arranged, the first lever 25 does not have a part that is operated by an operator. However, the first
and the second levers 25 and 26 are connected to a thin connecting member 27.
connected by. That is, the connecting member 27 is
The connecting member 271 engages the second lever 26 at its upper end 28 and extends downwardly through both sides of the first lever 25 , and its lower end 29 engages the second lever 26 . placed below. The connecting member 27
A compression coil spring 30 is disposed between the lower end portion 29 of the first lever 25 and the lower surface of the first lever 25 . This spring 30 biases the first lever 25 upwardly towards the second lever 26 . The second lever 26 is held in the idling position VtXU position iD shown in FIG. 7 by a biasing spring 31 acting between it and the main body 24,
The first lever 25 is held in its idle link position. the second lever 2 of the main body 24;
An adjustable stopper member 32 is installed on the side opposite to 6 so as to be slidable in the vertical direction. A contact surface of the main body 24 with the stopper member 32 is formed in a sawtooth shape, and the stopper member 32 is biased against the main body 24 by a spring (not shown). With this configuration, the stopper member 32 can be rotated vertically relative to the main body 24, moved to a desired position, and held at that position. The stopper member 3
2 is a stopper end portion 33 that protrudes into the interior of the main body 24;
has. On the other hand, the first lever 25 has a locking end 34 formed at its distal end that can engage with the lower surface of the stopper end 33 of the stopper member 32.

With this configuration, when increasing the speed of the internal combustion engine from idling speed, the second lever 26 is pressed with the index finger and middle finger.
is pivoted from the idling opening position of FIG. 7 to the intermediate opening position E of FIG. At this time, the first lever 25 is also constantly pushed upward by the spring 30, so it pivots from the idling opening position in conjunction with the second lever 26, but during the pivoting, the first lever 25 I) End portion 34
is engaged with the stopper end 33 of the stopper member 32, so that the first lever 25 is prevented from further pivoting and stops at the intermediate opening position B in FIG. to maintain the engine throttle valve in a predetermined intermediate fit state. When increasing the engine speed to the maximum speed as necessary, move the stopper member 32 by pushing it up to the highest position with your thumb as shown in Figure 9, and move the first lever 25 to its fully open position C. Set it so that it can pivot up to.

Next, the throttle device 36 of the fourth embodiment of the present invention shown in FIGS. 10 to 13 has a first lever 3 attached to the main body 37.
8 and the second lever 39 are arranged coaxially and pivotably independently of each other, but the lever 38 of 141 is
is substantially housed within the main body 36. The first lever 38 has an adjustment screw 4 threaded therethrough.
0 is installed, and the tip of this adjustment screw 40 engages with the upper side of the second lever 39. Said adjustment screw 4
0 is adjusted to the position corresponding to the desired opening of the throttle valve by absorbing the loosening of the threaded part by the compression coil spring 41 acting between the head and the first lever 38, and held in position.

Further, a safety lock lever 42 is pivotally attached to the main body 37, and the safety lock lever 42 engages the first lever 38 at its inner end to lock the first and second levers.
levers 38 and 39 are locked at the respective idle link speed M degrees i1A and D shown in FIG. Further, the first and second levers 38 and 39 are operated by biasing springs 43
Each side is biased towards the other. Furthermore,
As shown in FIG. 10, the first lever 38 shown in 11q is
A second gear segment 45 is provided within the body 37 and is oriented to coaxially fix a gear segment 44 and mesh with the first gear segment 44 . The second gear segment 45 is connected to the main body 3
An adjustment lever 46 is integrally provided on the outside of the controller 7 and can be operated by the operator with his/her thumb or the like. The second gear segment 45 is then moved towards the first lever 3 by means of a biasing spring (not shown) acting thereon.
The first tooth of 8 is held in the J1 meshing position away from the i1 segment 44. Furthermore, in this embodiment, the main body 3
An internal combustion engine stop switch 47 that can be operated with the thumb or the like is installed at 7.

With such a configuration, the internal combustion engine can be controlled at an idling speed of 1.
．． When increasing from q to a, first press the safety lock lever 42,
Push the handle 1 with the palm of your hand to remove its inner end from the first lever 38, and then use your index finger to move the second lever 39 from the 0 degree position to the 12th position (not shown in FIG. 11).
It is pivoted to the intermediate opening position E shown in the figure, and this pivoting force is transmitted to the first lever 38 via the adjusting screw 40. Therefore, the first lever 38 is pivoted in conjunction with the second lever 39 from the idling opening position A shown in FIG. 11 to the intermediate IFg position B (not shown in FIG.
48 to move the engine throttle valve from the idling opening position to the intermediate opening position. When it is desired to increase the engine speed further beyond the maximum speed, the WA clause lever 4
Rotate 6 in one direction with your thumb to turn the second gear segment 1.
-45 is engaged with the first tooth width segment 44, and the adjustment lever 46 is further rotated to pivot the first lever 38 to the open position C shown in FIG. At this time, adjust screw 4
0 away from the second lever 39 and the first lever 38 pivots independently from the second lever 39. To return the engine speed to the idle link speed, by releasing the second lever 39 and the adjustment lever 46, the first and second levers 38 and 39 are activated by the bias spring 1243 and the throttle valve return spring (f not shown). As a result, the valve immediately returns to the respective idling opening positions HA and D shown in FIG. 11, where it is safely locked by the automatically returned safety lock lever 42.

Detailed Description of the Invention With the configuration of the present invention, the present invention enables stable throttle operation to minimize operator fatigue;
Since the internal combustion engine can be reliably returned to the idling state when the lever is released, there is no danger during work, and the engine can be operated with minimal vibration and noise, and improved fuel efficiency. It's true.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a throttle device U for an internal combustion engine showing a first embodiment of the present invention in an idling opening state, and FIG. 2 is a sectional view showing the throttle device of FIG. 1 in an intermediate opening state. 3 is a cross-sectional view of the same section of the throttle device shown in FIG. 1, and FIG. 4 is a cross-sectional view of essential parts showing the idling opening state of the throttle device according to the second embodiment of the present invention. 5 is a sectional view showing the throttle device in FIG. 4 in an intermediate opening state, FIG. 6 is a sectional view showing the throttle device in FIG. 4 in a fully open state, and FIG. 7 is a sectional view showing the throttle device in FIG. FIG. 8 is a cross-sectional view of the main part of the throttle device according to the embodiment showing the idling opening state, FIG. 8 is a cross-sectional view of the throttle device shown in FIG. FIG. 10 is a perspective view of the main parts of the fourth embodiment of the present invention, excluding the main body and spring device, and FIG. Cross-sectional view showing the idling opening state of the throttle device d, No. 12
The figure is a cross-sectional view showing the throttle device shown in FIG. 10 in an intermediate opening state, and FIG. 13 is a cross-sectional view showing the throttle device shown in FIG. 10 in an intermediate opening state. 2.14.23.36...S [1 tuttle device,
3.15.24.37...Main body, 4.18.2
5.38...First lever 5.17, 26.3
9... Second lever 8.22.35.48...
... wire, 7.31.43 ... biased spring, 9 ... cam surface, 10.21, 30.41 ...
・・・Compression"Il spring, 11.18.40...
・Adjustment screw, 73...Cam follower θ) child, 27...
...Connecting member, 32... Stopper member, 42... Safety lock lever 43, 44... First and second gear segments,
46...adjustment lever

Claims (1)

[Claims] (1) a body (3) and a first lever (3) mounted on said body and operatively connected to a throttle valve of an internal combustion engine for pivoting between an idle position and a fully open position; 4), a second lever (5) provided on the main body so as to be pivotable between an idling opening position and an intermediate opening position, and a second lever (5) that is pivotable between an idling opening position and an intermediate opening position. interlocking means (12) for transmitting the pivoting movement between the opening position and the opening position to the first lever to pivot the first lever between the idling opening position and the intermediate opening position; and spring means for returning the first and second levers to idling opening positions.