JPH0422054Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a sliding valve type carburetor equipped with a plate-shaped sliding valve that intersects and slides with the main intake passage to control opening and closing of the main intake passage. or a constant negative pressure type vaporizer, more specifically, the guide surface of the plate-shaped sliding valve formed on the housing of the vaporizer is formed by casting a flat plate member instead of being formed by cutting. The present invention relates to a carburetor equipped with a plate-shaped sliding valve that enables integral molding of the casing of the carburetor by arranging and forming the same.

[Prior art]

In a sliding valve type carburetor or a constant negative pressure type carburetor in which a cylindrical piston is used as a sliding valve, the guide surface of the sliding valve formed on the carburetor housing is also cylindrical and integrally formed. A guide surface for a sliding valve can be formed by reaming a cylindrical hole formed by casting in a molded carburetor casing. However, in a carburetor that uses a plate-shaped sliding valve, the guiding surface of the sliding valve is flat, and milling must be performed after the housing is formed.
As disclosed in Japanese Patent Application No. 60-149862, the housing of the carburetor is formed in sections at the portion that guides the sliding valve. This will be explained using a diagram. FIG. 11 is a horizontal sectional view of a plate-shaped sliding valve type carburetor disclosed in Utility Model Application No. 60-149862, where reference numeral 1 denotes the housing of the carburetor, and the housing main body is located at the guide portion of the plate-shaped sliding valve 2. It is divided into two parts: 3 and an air funnel part 4. 5 is a main intake passage. As shown in FIG. 12, the sliding valve 2 has a front surface (downstream surface) 2-1 and a rear surface (upstream surface).
Flange portions 2-3 and 2-4 are formed, respectively, and the collar portions 2-3 are formed on the upstream end surface 6 of the main intake passage 5 of the housing body portion 3 and the downstream end surface 7 of the air funnel portion 4. The flange portion 2-4 is guided by a groove 8 formed in the air funnel portion 4 by casting. The surfaces 6 and 7 are machined into flat surfaces to serve as guide surfaces for the flange 2-3, but the groove 8 is sufficient if it serves as a relief for the flange 2-4, so it is not cast. It is still. Reference numeral 9 denotes a so-called smooth bore forming portion for reducing turbulence of the intake air flow in the main intake passage 5 in the portion of the slide valve 2;
-3 and 2-4.

[Problems with conventional technology]

In a carburetor equipped with a plate-shaped sliding valve 2, the casing 1 is formed in separate parts, as in the configuration disclosed in Japanese Utility Model Application Laid-Open No. 60-149862, which increases the cost.

[Means to solve the problem]

Instead of forming the flat surface on the side of the housing 1 that guides the plate-shaped slide valve 2 by cutting, it is formed by placing a flat plate member by casting.

[Structure of the idea]

In a carburetor equipped with a plate-shaped sliding valve that intersects and slides with a main intake passage to control the opening and closing of the main intake passage, at least The guide surface facing the front surface (downstream side surface) of the slide valve is formed by casting a flat plate member.

〔Example〕

FIG. 1 is a horizontal sectional view of the first embodiment of the present invention;
Figures 2 and 3 are cross-sectional views taken along the - and - arrows in Figure 1, respectively, where 1 is the carburetor housing, 2 is a plate-shaped sliding valve, 5 is the main intake passage, and 9 is the turbulence of the intake flow. Smooth bore forming part for reducing 10
is a flat plate member that forms a plane for guiding the slide valve 2, and is placed by casting during molding of the housing 1. FIG. 4 is a perspective view showing the shape of the flat plate member 10. The flat plate member 10 is formed in a U-shape and guides both the downstream and upstream sides 2-1 and 2-2 of the slide valve 2. 10a is an opening corresponding to the main intake passage 5, and 10b is an opening corresponding to the needle jet 11.

Although not directly related to the present invention, 12 is a fuel metering needle that fits into the needle jet 11 to form an annular fuel passage, and a needle clip 13
The slide valve 2 is attached to the slide valve 2 by a screw. FIG. 5 is a horizontal sectional view of a second embodiment of the present invention, and the symbols shown in the figure indicate the same parts as in FIG. A curved surface is formed that also guides both sides of the sliding valve 2. FIG. 6 is a perspective view of the flat plate member 10 used in the second embodiment.

FIG. 7 shows a third embodiment of the present invention, in which a flat plate member 10 shown in a perspective view in FIG. It forms the guide surface. Since the sliding valve 2 is strongly drawn downstream by the engine's intake negative pressure, in order to control the intake flow rate by opening and closing the sliding valve 2, a valve corresponding to the downstream surface of the sliding valve 2 is required. First of all, it is necessary that the surface of the housing 1 be flat, and depending on the engine in which the carburetor is used, the flat plate member 10 may only need to be placed on the downstream side of the sliding valve 2.

Symbols 5, 9, 10a, 10c are shown in Figures 5 and 6.
The same parts as in the figure are shown. Incidentally, when the flat plate member 10 is arranged on the upstream and downstream sides of the slide valve 2 as shown in FIG. 5, the flat plate member 10 shown in FIG. 8 is used instead of the flat plate member 10 shown in the perspective view of FIG. 10 to 2
You can also use one.

FIG. 9 shows the flat plate member 10 shown in the perspective view of FIG.
A fourth embodiment is shown in which the side edges 10d of the flat plate member 10 are folded back into a U-shape to form a flange 2-3 on the downstream side of the slide valve 2. This is a fourth embodiment in which a guide surface is also formed on the back surface of the device, and reference numerals 1, 5, 9, and 10a indicate the same parts as in FIG.

Although the members constituting the guide surfaces of the slide valve 2 have bent or folded portions, the individual surfaces that guide the slide valve 2 are flat, so they are called flat plate members 10.

The flat plate member 10 is made of a wear-resistant metal having a sufficiently high melting point that can be cast, such as a brass plate, a phosphor bronze plate,
Stainless steel plate etc. can be used.

[Action/Effect]

By using a flat plate member that is sufficiently flat and has a smooth surface as a guiding surface for a plate-shaped sliding valve, the guiding surface of the plate-shaped sliding valve can be formed without cutting. There is no need to separately mold the container casing, and a vaporizer with a plate-shaped sliding valve whose casing is integrally molded can be manufactured at low cost and with high precision.

[Brief explanation of the drawing]

Figures 1 to 3 show a first embodiment of a carburetor having a plate-shaped sliding valve according to the present invention, and Figure 4 shows a flat plate member that guides the plate-shaped sliding valve in the first embodiment. 5 and 6 are perspective views of the second embodiment and the seventh embodiment.
8 shows the third embodiment, FIGS. 9 and 10 show the fourth embodiment, and FIG. 11 shows the horizontal cross section of the plate-like sliding valve type carburetor disclosed in Utility Model Application No. 149862/1986. 12 are diagrams for explaining the structure of a plate-shaped sliding valve. Explanation of symbols, 1... Carburizer casing, 2... Plate-shaped sliding valve, 3... Main body of the casing, 4... Air funnel, 5... Main intake passage, 9... Disturbance of intake flow Smooth bore forming part for reducing 10
...Flat plate member, 10a...Opening corresponding to the main intake passage 5, 10b...Opening corresponding to the needle jet, 10c...Both side edges bent at right angles, 1
0a...Both edges folded back into a U-shape, 11...
Needle jet, 12...Fuel metering needle,
13...Needle clip.

Claims (1)

[Scope of utility model registration request] It intersects with the main intake passage 5 formed in the carburetor housing housing 1, which consists of a housing main body part and an air funnel part,
A carburetor equipped with a plate-shaped sliding valve 2 that slides to control opening and closing of the main intake passage 5, the sliding valve 2
a plate-shaped flange 2-3 including a front surface 2-1 (downstream side surface of the main intake passage) of the sliding valve 2 on both sides of the slide valve 2;
The smooth bore forming portion 9 of the guide portion of the slide valve 2 of the main intake passage 5 is formed by the plate-shaped flange 2-4 including the rear surface 2-2 (the upstream side surface of the main intake passage). A plate-shaped flange portion 2-3 having a groove therein and including a front surface 2-1 of the sliding valve 2 is provided in the main intake passage 5.
A safety groove and a guide groove of the plate-shaped flange 2-4 including the rear surface 2-2 are formed, and the front surface 2 of the guide groove of the flange 2-3 including the front surface 2-1 is formed. -1 and a surface of the guide groove of the flange 2-4 including the rear surface 2-2 that faces the rear surface 2-2, at least the front surface 2-1
By forming the surface facing the flat plate member 10 by casting and eliminating the need for cutting the surface, the housing main body portion 3 and the air funnel portion 4 can be separated.
A carburetor equipped with a plate-shaped sliding valve, characterized in that a carburetor housing 1 can be integrally molded without separating the two parts.