JPS63614B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a throttle valve operating device of the type that opens and closes a throttle valve of a carburetor by rotating an operating grip.

Regarding the carburetor, from the required characteristics of the carburetor itself or the engine equipped with it,
There are cases where it is required to make the opening characteristic of the throttle valve non-linear with respect to the rotation of the operating grip, and an object of the present invention is to provide a device with a simple structure that satisfies such a requirement. .

In order to achieve the above object, the present invention includes a housing fixed to a steering handle which rotatably supports an operating grip, and a control cam connected to the operating grip so as to rotate integrally with the housing. At the same time, the valve-opening wire and the valve-closing wire of the carburetor throttle valve are pivotally supported at the middle part of a swinging lever connected to both ends thereof, and the rotation of the control cam is oscillated in a non-linear relationship. A guiding member protruding from the swinging lever is slidably engaged with a cam groove provided in the control cam so as to transmit information to the lever.

An embodiment of the present invention will be described below with reference to the drawings. The illustrated example is a throttle valve operating device for a carburetor for a motorcycle. 1 is a housing that accommodates the device, and includes an upper housing 1a and a lower housing 1b.
These parts 1a and 1b are fixed on the handlebar H of the motorcycle by being connected with bolts 2 across the rod-shaped steering handlebar H of the motorcycle. Further, the upper housing 1a is divided into left and right parts to facilitate assembly of the internal mechanism, and are usually connected by bolts 3.

The inner end of a cylindrical operating grip 4 rotatably fitted to the right end of the steering handle H protrudes into the housing 1, and a control cam 5 is integrally formed or fixed to the inner end. The valve-opening rotation direction of the operating grip 4 and control cam 5 is indicated by A, and the valve-closing rotation direction is indicated by B.

The control cam 5 has a cam groove 6 on one side, and as shown in FIG. It is formed so as to gradually increase nonlinearly toward the valve closing rotation direction B of No. 5.

Further, within the upper housing 1a, an intermediate portion of a swinging lever 7 is swingably supported on one side wall of the upper housing 1a via a pivot 8. The swinging lever 7
has a pair of relatively long first and second arms 7a and 7b extending in opposite front and rear directions, and a relatively short third arm 7c that projects laterally from the base of the first arm 7a. A guide member 9 protruding from the side surface of the tip end of the three arms 7c is slidably engaged with the cam groove 6. In order to smoothly slide the guide member 9 in the cam groove 6, it is effective to fit a bearing 9a around the outer periphery of the guide member 9 as shown.

Both ends of the swinging lever 7, that is, the first and second arms 7
Connection terminals 10a and 11a of valve opening and valve closing wires 10 and 11 connected to a throttle valve of a carburetor (not shown) are attached to the tips of a and 7b, respectively.

In addition, 12 in FIG. 3 is a torsion coil spring that biases the operating grip 4 in the valve-closing rotation direction B, and 13 in FIG. With the stopper pin, housing 1
It is installed protruding from the inner wall.

Next, to explain the operation of this embodiment, when the operating grip 4 is rotated in the valve opening direction A in FIG. The member 9 is moved away from the rotation center of the control cam 5, and the movement is caused by the lever ratio ra/rc from the third arm 7c to the first arm 7a.
As the first arm 7a rotates upward and pulls the valve opening wire 10, the throttle valve of the carburetor is opened.

According to the illustrated shape of the cam groove 6, the change characteristic of the swing angle of the swing lever 7 with respect to the change in the rotation angle of the operating grip 4 and therefore the control cam 5 is as follows.
This is obtained as a non-linear characteristic as shown in the figure, and as a result, the opening speed of the throttle valve is slow in the first half of the valve opening and quickens in the second half, assuming the rotational speed of the operating grip 4 is constant.

When the operating grip 4 is rotated in the valve closing direction B from the open state of the throttle valve, the guide member 9 moves toward the rotation center of the control cam 5, contrary to the above case, and this movement causes the third arm 7c to rotate. Lever ratio from to second arm 7b
Since the second arm 7b swings upward and pulls the valve closing wire 11,
The throttle valve is closed.

As described above, according to the present invention, a housing is fixed to a steering handle that rotatably supports an operating grip, and the housing houses a control cam that is connected to the operating grip so as to rotate integrally therewith. At the same time, a valve-opening wire and a valve-closing wire of the carburetor throttle valve pivotally support the intermediate portion of a swinging lever connected to both ends, respectively, and the rotation of the control cam is directed to the swinging lever in a non-linear relationship. In order to transmit the information, a guide member protruding from the swing lever is slidably engaged with a cam groove provided in the control cam, so that the opening of the throttle valve relative to the rotation of the operating grip can be changed. Non-linear characteristics can be obtained, and the characteristics required for the carburetor and engine can be satisfied. Moreover, the cam mechanism consisting of the control cam and swing lever for obtaining the above characteristics can all be arranged near the operating grip, so even if the cam mechanism is specially installed, the throttle link etc. on the carburetor side can be mechanically adjusted. This method is advantageous in application to multiple carburetors, etc., in which the link mechanism around the carburetor is originally complicated. In addition, the forced opening and closing operations of the throttle valve can be controlled by a single control cam with a cam groove, and the control cam itself does not require a complicated interlocking mechanism in the operating grip. Since the cam mechanism can be connected coaxially, the structure of the cam mechanism is simple. Furthermore, the movement of the control cam can be controlled by simply selecting the effective lengths (ra, rb, rc) from the pivot point of the swing lever to the opening/closing wire end and guide member. The valve can be enlarged and efficiently transmitted to the valve opening and closing wires by using fixed lever ratios (ra/rc, rb/rc) suitable for each.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a rear view, FIG. 2 is a sectional view along the line - - of FIG. 1, and FIGS. 3 and 4 are sectional views of - and - of FIG. 2. , FIG. 5 is a diagram showing the swinging characteristics of the operating lever with respect to the rotation of the rotating cam of the control cam. 4...Steering handle, 1...Housing, 4...
...Operating grip, 5... Control cam, 6... Cam groove, 7... Rocking lever, 9... Guide member, 10...
...Wire for opening the valve, 11...Wire for closing the valve.

Claims (1)

[Claims] 1. A housing 1 is fixed to a steering handle H that rotatably supports an operating grip 4, and the housing 1 accommodates a control cam 5 that is integrally connected to the operating grip 4, and
A swinging lever 7 to which a valve opening wire 10 and a valve closing wire 11 of the carburetor throttle valve are respectively connected at both ends.
A guiding member 9, which is protruding from the swinging lever 7, is attached to the control cam 5 so that the rotation of the control cam 5 can be transmitted to the swinging lever 7 in a non-linear relationship. A throttle valve operating device for a carburetor, characterized in that it is slidably engaged with a provided cam groove 6.