JPH059629B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a carburetor that controls the amount and concentration of air-fuel mixture supplied to an engine, and in particular, a carburetor that controls the opening and closing of an intake passage by rotating a throttle valve. This invention relates to a so-called rotary throttle valve type carburetor chiyoke device.

[Conventional technology]

The throttle valve of the carburetor is controlled by the driver's accelerator wire to adjust and control the amount and concentration of the mixture supplied to the engine, and there are generally two types: a rotating type and a sliding type. It is broadly divided into .

The present invention relates to a starting device for a rotary throttle valve type carburetor using a rotary throttle valve.
The structure of Publication No.-98593 is known.

Although it is not described in the drawings of the above-mentioned specification, the choke device of these rotary throttle valve type carburetors is located upstream of the rotary throttle valve (air cleaner side).
A chiyoke valve for opening and closing the intake passage is disposed within the intake passage.

Specifically, the chiyoke valve is shown in FIG. 1. An intake passage 2 passes through the inside of the carburetor body 1, and inside the intake passage 2 is a chiyoke shaft rotatably supported on the carburetor body 1. 3 is arranged, and furthermore, a yoke valve 4 is attached to this yoke shaft 3.

Also, as shown in FIG. 2, a tire yoke valve 4 is rotatably disposed on the end face of the carburetor body 1 where the intake passage 2 opens, and this yoke valve 4 is attached to a yoke shaft 3 that is pivotally supported on the carburetor body 1. Ru.

Accordingly, the rotation of the exhaust shaft 3 causes the exhaust valve 4 to control the opening and closing of the intake passage 2.

[Problem that the invention seeks to solve]

According to such a conventional rotary throttle valve type carburetor chiyoke device, it has the following runner-up points.

In the case shown in Fig. 1, the chiyoke valve and chiyoke shaft always remain in the intake passage, which reduces the effective area of the intake passage and improves the suction efficiency of the carburetor. It's something that doesn't exist. Further, in order to increase the suction efficiency, it is possible to increase the diameter of the intake passage, but this makes it difficult to make the carburetor compact.

Also, when the chiyoke valve 4 is fully open,
This requires a length that allows the entire length of the intake valve 4 in the longitudinal axis direction of the intake passage 2, and this makes it difficult to shorten the overall length of the carburetor body.

In the case shown in FIG. 2, the chiyoke valve 4 slides and rotates on the end surface of the carburetor body 1 where the intake passage 2 opens. It is impossible to organize the vessels compactly.

[Means for solving problems]

[Function] The rotary throttle valve type carburetor chiyoke device of the present invention has been developed in view of the above-mentioned drawbacks, and the object is to obtain the device which is compact, has high suction efficiency, is easy to assemble, and is inexpensive. In order to achieve the above-mentioned purpose, from one side flat part of the carburetor body through which the intake passage passes, there is a throttle valve guide cylinder that is approximately perpendicular to and crosses the intake passage; A chiyoke valve rotation groove that is concentric and runs along the outer periphery of the throttle valve guide cylinder and across the intake passage; a chiyoke lever rotation recess that extends laterally from the upper end opening of the chiyoke valve rotation groove; A chiyoke operating groove provided at the bottom is bored, and a chiyoke valve having an arcuate cross section is rotatably arranged in the chiyoke valve rotation groove, and a lever portion extending to the side of the upper end of the chiyoke valve is inserted into the chiyoke lever rotation recess. At the same time, the engagement protrusion of the control knob movably arranged in the control groove is engaged with the engagement hole provided in the lever part of the control valve, while the throttle valve guide of the carburetor body is The flat part on one side where the tube, the yoke valve rotation groove, the yoke lever rotation recess, and the yoke operation groove open is closed with a stay plate that rotatably supports the throttle body, and the yoke operation knob is operated. In particular, the opening and closing of the intake passage is controlled by a chiyoke valve.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of a rotary throttle valve type carburetor according to the present invention will be described with reference to the drawings.

First, the carburetor main body 1 will be explained with reference to FIGS. 3 and 4.

Reference numeral 10 denotes a carburetor main body through which an intake passage 11 passes, and from a flat portion 10A on one side of the carburetor main body 10, a throttle valve guide tube 12, a chiyoke valve rotation groove 13, a chiyoke lever rotation recess 14, and A yoke operation groove 15 is bored.

That is, the throttle valve guide cylinder 12 has a flat portion 1 on one side.
It is perforated from 0A to be substantially perpendicular to the intake passage 11 and to cross the intake passage 11; Throttle valve guide tube 1
2, one side flat 10 of the carburetor main body 10
It is formed by casting from A to the bottom of the intake passage 11, and the groove length L in the rotating direction of the intake passageway 13 is such that the intake passage 11 remains in the intake passageway 11 when the intake passageway 11 is fully opened, which will be described later. It is bored in a range A that is outside the intake passage 11 so that the intake passage 11 can be accommodated without causing any damage, and on the other hand, it is bored across the intake passage 11 so that the intake passage 11 is located in a range B where the intake passage 11 can be blocked when the intake passage valve is fully closed. Ru.

Further, the chiyoke lever rotation recess 14 is formed on the outside of the chiyoke valve rotation groove 13 within a certain rotation range, and furthermore, the chiyoke lever rotation groove 1
5 has a linear groove shape and opens from the other surface of the carburetor main body 10.

Next, the yoke valve 16 accommodated in the yoke valve rotation groove 3 will be explained with reference to FIG.

The yoke valve 16 is the yoke valve rotation groove 1
A valve portion 16A formed in a shield shape with an arcuate cross section that can open and close the intake passage 11 in conformity with the shape of No. 3, and an engagement member that extends laterally from the valve portion 16A and is movable within the choke lever rotation recess 14. It consists of a forked lever portion 16B serving as a hole.

Reference numeral 17 denotes a yoke operation knob, which is shown in FIG. This has an engaging protrusion 17A on one end that engages with the forked lever portion 16B of the York valve 16, and a knob 17B on the end. Then, the operation knob 17 is placed in the operation groove 15, and the valve 16 is then assembled into the carburetor body 10.
The yoke valve 1 is inserted into the yoke valve rotation groove 13 from the opening of the flat part 10A on one side of the carburetor body 10.
Insert the valve part 16A of No. 6, and insert the lever part 16A.
Connect the forked part as the engagement hole of B to the Yoke operation knob 1.
It engages with the engagement protrusion 17A of No.7. This state is the seventh
This is clearly shown in the figure.

The solid line state of the yoke valve 16 and the yoke operation knob 17 indicates the fully open state of the yoke valve 16 with respect to the intake passage 11, and the state indicated by the chain double-dashed line in the figure in which the yoke operation knob 17 is pulled downward means that the yoke valve 16 is in a fully open state with respect to the intake passage 11. becomes fully closed.

Next, after placing the throttle body 21 having the needle 18, holder 19, and adjustment screw 20 inside the throttle valve guide cylinder 12, the shaft portion of the throttle body 21 is rotatably held by the stay plate 22, and the stay plate 22 is disposed and fixed on one side flat portion 10A of the carburetor main body 10, thereby closing the yoke valve rotation groove 13 and the yoke operation groove 15.

This is shown in FIGS. 8 and 9.

From the above, in the state shown by the solid line in FIG. 7 when the yoke operation knob 17 is pressed toward the carburetor main body 10 side, the engagement protrusion 17A of the yoke operation knob 17 presses the lever portion 16B of the yoke valve 16 clockwise. As shown in FIG. 9, the air intake path 11 of the air intake valve 16 can be fully opened, and on the other hand, when the engine operating knob 17 is pulled away from the carburetor body 10, the air intake valve 16 is rotated counterclockwise. This is to block the intake passage 11.

〔Effect of the invention〕

The rotary throttle valve type carburetor chiyoke device according to the present invention has the following effects.

Since the chiyoke valve is formed substantially concentrically with the rotary throttle valve, the chiyoke valve can be made shorter in the longitudinal axis direction of the intake path of the carburetor body, compared to a valve that is attached to a chiyoke shaft that passes through the intake path.

In addition, compared to a structure in which the chiyoke valve is rotatably arranged on a shaft placed on the short side of the intake path of the carburetor body, the full opening of the chiyoke valve can be kept low.In addition to the above effects, when the chiyoke valve is fully opened, Since no chiyoke valve remains in the intake passage, the suction efficiency of the intake passage can be improved.

A chiyoke device is formed by a chiyoke valve and a chiyoke lever, and it is no longer necessary to attach the chiyoke shaft and chiyoke valve, and its upper part is closed with a stay plate that serves as a bearing for the throttle body. There is no need to worry about the screws loosening due to engine sliding and being sucked into the engine, making it possible to improve the reliability of the carburetor and significantly reduce its manufacturing cost.

By making the Chiyork valve have an arcuate cross section, it is placed in the intake passage (when the Chiyork valve is fully closed), and when the negative pressure of the engine's intake passage acts on the Chiyork valve, the flat Chiyork valve has a resistance against deformation. This improved the results.

The Chiyoke lever is placed in the concave part of the opening end of the carburetor body in the Chiyoke valve rotation groove, making it possible to reduce the overall height of the carburetor.
This greatly improves the degree of freedom in attaching it to the engine.

By forming the check valve and the check valve operating knob from a resin material, the locking protrusion provided on the check valve itself can provide a bending effect for holding the check valve. According to this, when the check valve is fully opened, It can be reliably maintained in a fully closed state.

[Brief explanation of the drawing]

1 and 2 are external views showing a conventional carburetor chock device, and FIG. 3 is a vertical sectional view showing the carburetor main body of a rotary throttle valve type carburetor chock device according to the present invention. FIG. 4 is a top plan view thereof, FIG. 5 is a perspective view of a chiyoke valve used in the present invention, FIG. 6 is a chiyoke lever similarly used in the present invention, and FIG.
The figure is a plan view of the carburetor body with the Chi-Yoke lever and Chi-Yoke valve assembled, Figure 8 is a vertical cross-sectional view of the rotary throttle valve type carburetor in its final assembled state, and Figure 9 is a cross-sectional view along the line shown in Figure 8. It is a front view. 10... Carburetor body, 11... Intake path, 12...
... Throttle valve guide cylinder, 13... Choy yoke valve rotation groove, 14... Choy yoke lever rotation recess, 15...
Chi yoke operating groove, 16... Chi yoke valve, 17
...Chiyoke operation knob, 22...Stay plate.

Claims (1)

[Scope of Claims] 1. From a flat part on one side of the carburetor main body through which the intake passage passes, a throttle valve guide cylinder that is substantially orthogonal to and crosses the intake passage, and approximately concentric with the throttle valve guide cylinder. A yoke valve rotation groove that extends laterally from the upper end opening of the yoke valve rotation groove on the outer periphery of the throttle valve guide cylinder and across the intake passage; A chi-yoke operation groove provided is bored, and a chi-yoke valve having an arcuate cross section is rotatably arranged in the chi-yoke valve rotation groove, and a lever part extending to the side of the upper end of the chi-yoke valve is arranged in the chi-yoke lever rotation recess. At the same time, an engagement protrusion of a chiyoke operating knob movably disposed in a chiyoke operating groove is engaged with an engagement hole provided in a lever portion of the chiyoke valve, while a throttle valve guide cylinder of the carburetor main body, A rotary throttle valve type carburetor in which the flat part on one side where the throttle valve rotation groove, the throttle lever rotation recess, and the throttle operating groove are opened is closed by a stay plate that rotatably supports the throttle body. Chiyoke device. 2. The control device for a rotary throttle valve type carburetor according to claim 1, wherein the control knob is made of a synthetic resin material. 3. A rotary throttle valve type carburetor chiyoke device according to claim 1, wherein the chiyoke valve is formed of a synthetic resin material.