JPS6341546Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a horizontal carburetor in which the main intake passage is arranged horizontally, a float chamber is provided below the main intake passage, and a chiyoke valve that rotates around a vertical axis, such as a general-purpose The present invention relates to a carburetor that reduces costs by reducing the number of processing steps and assembly steps for the vaporizer. In order to reduce the cost of the carburetor, we have made it possible to selectively assemble the mutual directional relationship of each housing part that makes up the carburetor.
Proposals for a housing configuration that can be commonly used for different engines are disclosed in JP-A-50-21140, JP-B No. 49-22972, and JP-B No. 50-35606. The first principle is to reduce the number of processing steps required after molding the carburetor body (mixing chamber body). Conventionally, when molding the main body of a carburetor with the configuration listed at the beginning, it was possible to simultaneously mold the butterfly valve bearing hole located on the upper side of the main body by casting, but the hole located on the lower side of the main body could be formed at the same time. The bearing hole had to be cut after the main body was molded. The present invention eliminates the machining of the bearing hole on the lower side, and along with this, among the butterfly valves,
In order to reduce the number of man-hours required for machining the bearing hole on the lower side of the choke valve, the first objective is to provide a carburetor with a configuration that can also eliminate the machining of the bleed air jet of the main fuel system (described later). shall be. Next, as a proposal to reduce costs by reducing the number of man-hours required for assembling the carburetor, the butterfly valve is provided with a valve rotation shaft insertion hole with a circular cross section centered around the valve rotation center line. a pin is provided on the valve rotation shaft in a direction perpendicular to the valve rotation shaft, and the pin is engaged with a pin hole provided in the wall of the valve rotation shaft insertion hole; A configuration in which a tapered slot is provided between the pin hole and the end face of the valve rotation shaft insertion hole was developed in 1983.
105632, but the result is substantially the same as using a large diameter valve rotation shaft, and the flow of air or mixture in the main intake passage when the butterfly valve opening is large. It becomes an obstacle. A carburetor with a configuration that can reduce the number of assembly steps for assembling the butterfly valve and valve rotation shaft to the carburetor body without causing obstruction to the flow of air or air-fuel mixture when the opening degree of the butterfly valve is relatively large. The second purpose of the present invention is to provide a container, and the first and second
The key point is that the bearing hole on the lower side of the carburetor main body is provided in a bearing block that can be slid in the direction of the center line of the main intake passage and is molded separately from the carburetor main body. is provided with a hollow cylindrical part whose center line is the center line of rotation of the butterfly valve, the hollow cylindrical part is formed flat parallel to the surface of the butterfly valve, and a flat cylindrical part is formed inside the flat cylindrical part. The purpose is to insert the valve rotation shaft.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the vaporizer of the present invention will be explained in detail below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a first embodiment of the vaporizer of the present invention. In Fig. 1, numeral 1 is the carburetor main body, 2 is the main intake passage, 3 is the choke valve,
Reference numeral 4 denotes a hollow cylindrical portion formed integrally with the above-mentioned yoke valve 3, with the center line of rotation of the yoke valve 3 as its center line, and 5 indicates a yoke valve rotation fitted into the hollow cylindrical portion 4. It is a moving shaft and is integrally formed with a shaft neck 6 on the upper side of the carburetor main body 1 and a choke lever 7. In order to rotate the Chiyork valve 3 by rotating the Chiyork lever 7, in this embodiment, as will be described later, both the hollow cylindrical portion 4 and the Chiyork valve rotation shaft 5 are formed flat. ing. Since the flat plane of the hollow cylindrical portion 4 is parallel to the surface of the chiyoke valve 3, when the degree of opening of the chiyoke valve 3 is large, the hollow cylindrical portion 4 absorbs the air in the main intake passage 2. Does not impede flow. 8 is a sliding split installed in the lower part of the lower part of the chiyoke valve dynamic shaft 5, and 9 is a straightforward direction at the lower end of the chiyoke valve dynamic axis 5. It's a nail. The yoke valve rotation shaft 5 can be fitted into the hollow cylindrical portion 4 by elastically narrowing the sliding width by the protruding height of the pawl 9. (After the fitting is completed, the sliding portion 8 elastically opens and returns to its original state).

Reference numeral 10 denotes a shaft neck portion on the lower side of the choke valve 3 extending below the hollow cylindrical portion 4, which has a circular cross-sectional shape on its outer peripheral surface, and is supported by a bearing hole provided in a bearing block 11. Ru. The bearing block 11 is molded separately from the carburetor body 1, and is inserted into a groove provided in the carburetor body 1 in the direction of the main intake passage 2. A gap 12 is reserved between the inner end surface of the groove provided in the carburetor main body 1 and the end surface of the bearing block 11 that faces the inner end surface of the groove, and the carburetor main body 1
At the time of molding, a space is secured at the same time to form a passage for bleed air flowing into the bleed air jet 13 of the main fuel system, which is formed by casting. A stepped portion is formed inside the lower shaft neck portion 10,
The pawl 9 engages to prevent the valve shaft 5 from coming out after being fitted.

Figure 2 is a view of Figure 1 viewed from the direction of the arrow.
The same parts as in the figures are denoted by the same reference numerals (the same applies hereinafter), and the reference numeral 14 is a groove (described above) provided in the carburetor main body 1 into which the bearing block 11 is inserted. 3 is a cross-sectional view taken in the direction of the - sectional arrow in FIG. In the figure, the width w of the flat chiyoke valve rotation shaft 5 is
In order to provide the pawl 9, the diameter is smaller than the diameter of the shaft neck portion 6. FIG. 6 shows the hollow cylindrical part 4.
In a partially cross-sectional front view of the chiyoke valve 3 which is integrally molded with the valve 3, reference numeral 15 indicates a step portion (described above) with which the pawl 9 engages. FIG. 7 is a view of FIG. 6 viewed from the direction of the arrow. Since the angles α and α' of the cross section of the outer circumferential edge of the check valve 3 are formed to be the same angle, the check valve 3 can be fully opened by rotating counterclockwise even when the rigging is fully opened by rotating clockwise. It has the advantage that it can also be used for rigging. Returning to FIG. 1, 20 is the throttle valve, 21 is the throttle valve rotating shaft, 22 is the upper shaft neck, 23 is the lower shaft neck, 24 is the throttle valve lever, 25 is the upper bearing hole, 26 is the bearing hole on the lower side. The throttle valve 20 is attached to the throttle valve rotating shaft 21 with screws 27. Upper bearing hole 25
is formed by casting at the same time as the carburetor body 1 is molded; however, since the bearing hole 26 on the lower side cannot be formed by casting, it is of the conventional type, which is machined after casting. The throttle valve side is shown for comparison and contrast with the carburetor of the present invention. To explain the parts of the carburetor shown in FIG. 1 other than those mentioned above, 30 is a bleed tube, and 31 is a main fuel jet, which is molded from synthetic resin.
The bleed tube 30 is elastically pushed up by the inner bottom surface of the bleed tube 30 to maintain close contact with the lower end surface of the bleed tube 30.

Next, the advantages of the present invention will be explained, but in order to make it easier to understand, the procedure for assembling the choke valve 3 to the carburetor body 1 will be explained first. The shaft neck 10 formed integrally with the choke valve 3 is inserted into the bearing hole of the bearing block 11, and the bearing block 11 is inserted into the bearing block insertion groove 14 of the carburetor main body 1. Next, grip the Chiyoke lever 7, insert the Chiyoke valve rotation shaft 5 into the hollow cylindrical portion 4 of the Chiyoke valve 3, and engage the pawl 9 with the stepped portion 15 to complete the assembly of the Chiyoke valve. do.

Since the bearing block 11 does not exist on the upstream side of the bleed air jet 13 before the choke valve 3 is assembled, the bleed air jet 13 is formed by casting at the same time when the carburetor main body 1 is molded. be able to.

The lower bearing hole is formed by casting at the same time as the separate bearing block 11 is formed, so there is no need for cutting after forming the carburetor body as in the conventional case, and materials suitable for the bearing are selected and used. can. By maintaining a gap between the opening end surface of the bleed air jet 13 and the inner end surface of the bearing block 11 even after the cheese yoke valve 3 is assembled, a bleed air passage can be secured, and the size of the gap 12 can be maintained. The characteristics of the bleed air jet can be changed by selecting the shape and opening position, that is, the height, shape, and depth of the end of the bearing block 11.

FIG. 8 shows a second embodiment in which the end face shape of the bearing block 11 of the carburetor of the present invention is modified, and the upper surface of the bearing block 11 has a recess 1 on the downstream side of the bearing hole.
6, and a protrusion 17 having a circular cross section with a bleed air jet 13 opening at the center is provided on the end face opposite to the inner end face of the groove 14.
A through hole 18 into which the protrusion 17 is hermetically fitted, instead of opening the bleed air jet 13, is formed on the inner end surface of the carburetor body 1 at the same time as the carburetor main body 1 is formed. The through hole 18 communicates with the fuel well surrounding the bleed tube 30. With this configuration, it is possible to adapt to engine characteristics by replacing the bearing block 11 without changing the hole (bleed air hole) on the side of the carburetor main body 1. When the configuration of the choke valve 3, the choke valve rotating shaft 5, and the bearing block 11 described above is applied to the throttle valve 20, the lower side of the carburetor main body 1 is not related to the casting of the bleed air jet. As with the Chi-Yoke valve, the bearing hole is not cut after the carburetor body is formed, and the number of steps required to assemble the throttle valve is reduced.

Furthermore, even if the valve rotation shaft 5 is fitted into the hollow cylindrical part 4 formed integrally with the York valve 3, the hollow cylindrical part 4 is formed flat, so the opening degree of the butterfly valve is large. When the valve is air,
In the case of a throttle valve, it does not obstruct the flow of the air-fuel mixture, and since the width w of the rotating shaft (FIG. 5) can be made large, a sufficient torque for rotating the butterfly valve can be obtained. It is also possible to use a conventional butterfly valve and rotating shaft in a configuration using the bearing block 11.

The vaporizer having the structure of the present invention as described above can achieve the first and second objects listed at the beginning.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of the first embodiment of the carburetor of the present invention, Fig. 2 is a view of the carburetor of Fig. 1 seen from the direction of the arrow, Fig. 3 is a - sectional view, and Fig. 4 is a longitudinal sectional view of the first embodiment of the carburetor of the present invention. An enlarged view of the rotating shaft of the Chiyork valve, Figure 5 is a cross-sectional view taken in the direction of the arrow, Figure 6 is a partially sectional front view of the Chiyork valve, and Figure 7 is a view of the Chiyork valve seen from the direction of the arrow. , FIG. 8 shows a second embodiment of the vaporizer of the present invention. Explanation of symbols, 1... Carburetor main body, 2... Main intake passage, 3... Chi York valve, 4... Hollow cylindrical part, 5... Rotating shaft of Chi York valve, 8... Sliding, 9... Claw, 10... Lower side shaft neck, 11... bearing block, 12... gap,
13... Bleed air jet, 14... Bearing block insertion groove, 15... Step portion, 20... Throttle valve.

Claims (1)

[Claims for Utility Model Registration] (1) In a carburetor having a horizontal main intake passage 2 with a chiyoke valve 3 that rotates about a vertical axis, the chiyoke valve 3 is located on the lower side of the chiyoke valve 3. A hollow cylindrical shaft neck portion 10 is integrally formed,
A bearing block 11 in which a bearing hole for supporting the shaft neck 10 is formed is formed separately from the main body 1 of the carburetor and is inserted into a groove 14 formed in the main body 1 of the carburetor. A bleed air passage that guides bleed air to the main fuel system of the carburetor is opened at the inner end surface of the carburetor. is formed, and a flat valve rotation shaft 5 for rotating the valve valve 3 is fitted into the flat hollow cylindrical portion 4, so that the inner surface of the flat hollow cylindrical portion 4 and the inner surface of the shaft neck portion 10 are connected to each other. A carburetor in which a stepped portion 15 is formed at the connecting portion, with which a pawl 9 formed at the lower end of the valve rotation shaft 5 engages. (2) The inner end surface of the groove 14 and the bearing block 11
forming an air passage communicating with the bleed air passage by forming a gap 12 between the air passage and the inner end surface of the air passage;
The carburetor according to claim 1, wherein the intake hole is a bleed air jet 13. (3) A circular cross-section in which a recess 16 is formed on the upper surface of the bearing block 11 on the downstream side of the bearing hole, and a bleed air jet 13 that opens into the recess 16 is formed at the inner end of the bearing block 11. A bleed air passage opening at the inner end surface of the groove 14 is provided with a protrusion 17 .
The vaporizer according to claim (1) of the above-mentioned utility model registration, wherein a through hole 18 is formed into which a hole 18 is inserted.