JPS6154938B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a throttle valve actuation link of an internal combustion engine carburetor;
In particular, it relates to an operating mechanism in which the action of a torsion spring is interposed in the rotational movement of a throttle valve shaft.

The throttle valve operating link part as mentioned above is made by JP-A-Sho.
It has been proposed in Publication No. 57-56635, etc., and one example is shown in Fig. 1 as a vertical side view. 1 is the carburetor body, 2 is the throttle valve, 3 is the throttle valve shaft, 4 is the carburetor body 1
5 is a dish-shaped collar presser pivotally supported on the throttle valve shaft 3; 6 is a collar portion of the collar presser 5;
7 and 8 are cylindrical collars with flanges that receive and guide the large-diameter torsion spring 9, 10 and 11 are cylindrical collars with flanges that receive and guide both ends of the small-diameter torsion spring 12, and 13 and 14 are throttle valve shafts, respectively. a cylindrical sleeve 1 which is pivotally supported by 3 and is interposed between the cylindrical collars 7 and 10 and between the cylindrical collars 8 and 11 to prevent mutual contact or interference between the torsion springs 9 and 12;
5 is a torsion spring end locking pin fixed to the carburetor main body 1, and 16 is a throttle valve lever connected to the shaft end of the throttle valve shaft 3. The above torsion springs 9 and 1
The respective outer ends of the springs 2 are engaged with engaging portions 17, 17 formed on the throttle valve lever 16, and the inner ends of the springs 2 are engaged with the pin 15, whereby both the torsion springs 9 and 12 are The spring is wound around the throttle valve shaft 3 so that the spring force acts in the direction of closing the throttle valve 2.

2 and 3 respectively show a plan view and a side view of the cylindrical collar presser foot 5 with the collar 6,
4 and 6 are cross-sectional views taken along the line AA in FIG. 1 (however, the torsion spring 12 is not shown) when the throttle valve 2 is fully closed and fully opened, respectively. As shown in the figure, the cylindrical collar presser 5 and the cylindrical sleeve 13 each have a notch end 5' that sandwiches a notch part over an angular range α corresponding to the rotation angle of the throttle valve shaft 3.
5'' and 13', 13'' are formed, and the gas sleeve 13 on the inner end side of the torsion spring 12 and the collar It is pulled out from the cylindrical inner space of the presser foot 5 and is locked to the pin 15 .

In FIGS. 4 and 5 above, the torsion spring 9
At the contact point of the torsion spring 9 with respect to the tangent from the inner end side locking pin 15, the receiving collar 7 is directed toward the cylindrical sleeve 13 by a component of the torsion force of the torsion spring 9 in the direction of the axis 3. As a result, a pressing force is exerted to the left in the figure. Therefore, in the fully closed state of the throttle valve shown in FIG. 1
A deforming force acts on the collar 7 between 3' and 13'' toward the notch.On the other hand, when the throttle valve is fully open as shown in FIG.
Both points contact the inner surface of the collar 7, and strong contact friction and deformation force are exerted by the spring force, which is maximum when fully opened. Therefore, each time the throttle valve 2 opens and closes, the sliding friction between the inner surface of the cylindrical collar 7 and the sharp outer end point a of the notched end 13' of the sleeve 13 is repeated, especially when the throttle valve 2 is close to being fully opened. Sleeve 1 in condition
Strong sliding friction is maintained between both points a and b of the notched ends 13' and 13'' of the sleeve 1. The cylindrical collar 7 between the points a and b is
Since the notch 3 is on the back, deformation force is not exerted by the axial component of the spring force of the torsion spring 9 as described above, so the sliding friction at both points a and b is further strengthened. Severe wear is unavoidable whether the cylindrical collar 7 is made of metal or plastic.

Furthermore, as described above, between the inner surface of the cylindrical collar 7 and the cutout ends 13' and 13'' of the sleeve 13,
Since a strong frictional resistance is generated due to the strong mutual pressing force at points a and b, the cylindrical collar 7 is hooked without rotating along the cylindrical surface of the cylindrical sleeve 7 that is loosely fitted. It becomes a state of being. Therefore, the frictional resistance between the torsion spring 9 in contact with the collar 7 and the collar 7 increases, and the return operation of the torsion spring 9 to return the throttle valve 2 from the open state to the fully closed state is weakened.
This tends to cause the operation to become unsmooth or impossible.

The present invention aims to solve the above-mentioned difficulties caused by the presence of a notch in the cylindrical sleeve in the conventional throttle valve actuation link using a double torsion spring, and is disclosed in the above-mentioned patent. As described in the claims section, the present invention is characterized in that a stopper portion is formed on the collar portion of the dish-shaped collar presser for restricting displacement of the collar portion of the cylindrical collar in the radial direction.

6 to 8 show one embodiment of the present invention, in which FIG. 6 is a plan view of the dish-shaped collar presser 5, FIG. 7 is a side view thereof, and FIG. 8 is a longitudinal sectional side view of the main part. Reference numeral 18 in each figure indicates a stopper portion that is provided on the outer peripheral edge of the collar portion 6 of the dish-shaped collar presser 5 in a manner that projects parallel to the direction in which the throttle valve shaft 3 protrudes. The stopper part 1
8 surrounds the outer circumferential edge of the cylindrical collar 7 with a minute or very small interval, and limits displacement of the cylindrical collar 7 in the radial direction within a minute or very small range.

Due to the presence of the stopper portion 18, the outer periphery of the collar portion of the cylindrical collar 7 and the stopper portion 18 of the dish-shaped collar presser 5 are maintained concentrically, so that the cylindrical sleeve 13 and the dish-shaped collar presser 5 are coaxial with each other. Since the relative relationship between the mutually concentric cylindrical portions of the collar 7 and the cylindrical portion of the collar 7 is also maintained concentrically, the relative relationship between the mutually concentric cylindrical portions of the collar 7 and the cylindrical portion of the collar 7 is maintained concentrically. The cylindrical collar 7 can now be prevented from taking an eccentric position. This makes it possible to reliably prevent wear and deformation caused by pressure contact between the notched ends 13' to 13'' of the cylindrical sleeve 13 and the inner surface of the cylindrical collar 7. By eliminating or reducing the frictional resistance between the torsion spring 7 and the cylindrical sleeve 13, the conventional drawback in which the cylindrical collar 7 exerts strong frictional resistance on the torsion spring 9 and inhibits the spring operation can be overcome. This allows the torsion spring 9 to exhibit its original smooth collar action.

In FIGS. 6 and 7, the stopper part 18 is arranged so that the collar part 6 of the cylindrical collar presser 5 is attached to the outer periphery of a fan-shaped band sandwiched between two concentric arcs of the outer periphery and the inner periphery. It is formed to face the outer peripheral edge of the collar portion of the cylindrical collar 7 in the radial direction. According to such a configuration, when the throttle valve 2 is opened, the contact point of the inner surface of the stopper portion 18 with the outer peripheral edge of the collar portion of the cylindrical collar 7 gradually changes;
Further, when the throttle valve 2 is operated, the cylindrical collar 7 moves while rotating.

FIG. 9 shows another embodiment of the present invention,
Reference numeral 19 denotes a collar portion of the dish-shaped collar presser 5; 20 and 21 denote edges of the notch; and 22 denotes an outer peripheral edge of the collar portion of the cylindrical collar 7 parallel to the protruding direction of the throttle valve shaft 2 on the outer peripheral edge of the collar portion 19. This is a stopper portion formed to face the. The fan-shaped band formed by the flange 19 is not a band sandwiched between concentric circles as in the case of FIGS. It is formed in a kind of open hem shape, the length of which is larger than the length in the middle region. Therefore, the distance from the axis of the stopper part 22 protruding from the outer peripheral edge of the collar part 19 is longer at both notched ends 20 and 21 than at the middle part, and the distance from the axis of the stopper part 22 protruding from the outer peripheral edge of the collar 19 is longer. The distance between the stopper portion 22 and both notch edges 2
It is formed so that it increases as it approaches 0.21. According to such a configuration, the stopper portion 22
It is possible to eliminate the possibility that the notch edge contacts the outer peripheral edge of the collar portion of the cylindrical collar 7 and obstructs the movement of the collar 7, and also prevents the cylindrical collar 7 from moving in any direction due to engine vibrations, etc. Even when an indiscriminate force is applied, there is no fear of interference or catching between the collar 7 and the stopper portion 22, and stable link operation can be maintained.

As described above, the present invention has a remarkable feature in that it has solved the conventional problems regarding the throttle valve actuating link part by extremely simple means.

[Brief explanation of the drawing]

Figures 1 to 5 show a conventional example, where Figure 1 is a longitudinal sectional view of the device, Figure 2 is a plan view of the collar presser, Figure 3 is a side view, and Figures 4 and 5 are respectively diaphragms. FIG. 1 is a sectional view taken along the line AA in FIG. 1 when the valve is fully closed and when the valve is fully open. 6 to 8 and 9 show different embodiments of the present invention, in which FIG. 6 is a plan view of the collar presser foot, FIG. 7 is a side view, FIG. 8 is a sectional view of main parts, and FIG. The figure is a plan view of the collar presser foot. 1... Carburetor main body, 2... Throttle valve, 3... Throttle valve shaft, 4... Support arm, 5... Dish-shaped collar presser, 6...
...Brim portion, 7, 8, 10, 11...Cylindrical collar,
9, 12... Torsion spring, 13, 14... Cylindrical sleeve, 15... Locking pin, 16... Throttle valve lever, 17... Locking part, 18... Stopper part, 1
9...Brim part, 20, 21...Notch end, 22...
Stopper part, 5', 5'', 13', 13''...notch end.

Claims (1)

[Scope of Claims] 1. In a throttle valve operating link used in an internal combustion engine, a torsion spring is wound and tensioned around a throttle valve shaft so as to act in a direction to close the throttle valve; a cylindrical collar with a flange that is supported and guides the torsion spring; and a flange portion that opposes the axial thrust of the cylindrical collar that is pivotally supported on the throttle valve shaft. and a stopper portion for restricting displacement of the collar portion of the cylindrical collar in the radial direction is formed on the collar portion of the dish-shaped collar retainer. 2. The collar of the cylindrical collar presser is formed as a fan-shaped band sandwiched between two mutually concentric arcs of the outer peripheral edge and the inner peripheral edge, and the outer periphery of the collar of the cylindrical collar is attached to the outer periphery of the fan-shaped band. 2. The throttle valve actuating link part according to claim 1, further comprising a stopper part facing in the radial direction. 3. Of the distance in the radial direction between the arcuate inner circumferential edge of the fan-shaped band-shaped area forming the collar of the cylindrical collar presser and the outer periphery from which the stopper part is protruded, both ends of the sector-shaped band-shaped area 2. The throttle valve actuating link portion according to claim 1, wherein the distance between the two ends is greater than the distance between the two ends.