JPS6313415Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is characterized in that a float chamber body for forming a float chamber body is coupled to a lower part of a carburetor body, particularly a carburetor body having an intake passage, and a float chamber body for forming a float chamber body is connected to a bottom part of the float chamber body. A carburetor is provided with a holder extending toward the carburetor, and a pair of fuel jets communicating with a fuel nozzle opened in the intake passage are fitted in parallel to a lower end of the holder located below the fuel oil surface. .

Conventionally, in such a carburetor, in order to facilitate attachment of the fuel jet, the fuel jet fitted into the holder is held by a coil spring interposed between the holder and the bottom of the float chamber body. Moreover, in order to hold both fuel jets with a single coil spring, a common spring receiving member is installed between both fuel jets, as shown in, for example, Japanese Utility Model Application Publication No. 58-40545. Either a coil spring is interposed between the bottom of the float chamber body, or, as shown in Japanese Utility Model Application Publication No. 186153/1984, both fuel jets are made into a single part and a coil is inserted between it and the bottom of the float chamber body. Although a spring is interposed, especially in the former case, it is necessary to specially provide a common spring receiving member for both fuel jets, which causes problems such as a complicated structure, increased cost, and troublesome assembly. Especially in the latter case, since both fuel jets are made into a single part, when the effective diameter of one fuel jet is changed, it is necessary to straighten and replace the entire jet, including both jets, which increases the cost. There are problems such as high temperatures.

The object of the present invention is to provide a carburetor with a simple structure that can solve all of the above problems.

In order to achieve the above object, the present invention provides a float chamber body for forming a float chamber coupled to a lower part of a carburetor body having an intake passage, and a holder extending toward the bottom of the float chamber body. In the carburetor, in which a pair of fuel jets communicating with a fuel nozzle opened in the intake passage are fitted in parallel to the lower end of the holder located below the fuel oil level, one of the fuel jets A single coil spring disposed substantially concentrically with respect to the float chamber body is interposed between the one fuel jet and the bottom of the float chamber body, and extends laterally from one end of the coil spring. It is characterized in that the engaging portion is engaged with the other fuel jet, and both fuel jets are held at the lower end of the holder by the spring force of the coil spring.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, in FIGS. 1 and 2, this carburetor 1 is used in a general-purpose engine such as a lawn mower engine, and is mounted almost horizontally. A synthetic resin float chamber body 4, which is basically a cylinder with a bottom, is fitted into the lower part of the synthetic resin carburetor main body 3 in which an intake passage 2 is bored in the direction, via a sealing member 5. They are connected by means of engagement means that do not. Thereby, a float chamber 6 is defined below the intake passage 2.

A bench lily 7 is provided in the middle of the intake passage 2,
A choke valve 9 is pivotally supported on the carburetor body 3 upstream of the bench lily 7 along the intake direction shown by an arrow 8, and a throttle valve 10 is pivotally supported downstream of the bench lily 7.

A holder 11 is integrally provided at the lower part of the carburetor body 3 at a position corresponding to the bench lily 7 and extends downward toward the bottom 4a of the float chamber body 4. The lower end of this holder 11 is located below the fuel oil level l in the float chamber 6. A main fuel nozzle 13 that integrally includes a bleed pipe 12 at the bottom and opens facing the intake passage 2 is fitted into this holder 11, and a main fuel jet 14 that concentrically abuts the lower end of the bleed pipe 12 is fitted into the holder. It is fitted to the lower end of 11. An annular chamber 15 is formed between the outer surface of the bleed pipe 12 and the inner surface of the holder 11, and this annular chamber 15 is connected to the upstream end of the intake path 2 via an air bleed passage 16 bored in the carburetor body 3. communicated.

A low-speed fuel passage 17 is bored in the holder 11 in parallel with the main fuel nozzle 13, bleed pipe 12, and main fuel jet 14, and a low-speed fuel jet 18 is provided at the open end of the low-speed fuel passage 17 at the lower end of the holder 11. Fitted. On the other hand, throttle valve 1
A low-speed fuel chamber 19 is defined in the lower part of the carburetor main body 3 at a position corresponding to 0, and this low-speed fuel chamber 1
9 is communicated with the low speed fuel passage 17. Further, the low-speed fuel nozzle 20 opens into the intake passage 2 slightly downstream of the throttle valve 10, and the bypass port 21 opens into the intake passage 2 slightly upstream of the fully closed position of the throttle valve 10. It is bored in the carburetor body 3 and commonly communicates with the low-speed fuel chamber 19 .

The fitting structure of the main fuel nozzle 13, bleed pipe 12, main fuel jet 14 and low-speed fuel jet 18 will be described in detail with reference to FIG.
A small diameter portion 22 through which the main fuel nozzle 13 is inserted, a medium diameter portion 24 that connects to the small diameter portion 22 via a step portion 23 facing downward and forms an annular chamber 15 between it and the bleed pipe 12; A large diameter part 2 which is connected to the medium diameter part 24 via the facing step part 25 and into which the main fuel jet 14 is fitted with an O ring 27 attached to its outer peripheral surface.
A hole consisting of 6 is drilled.

On the other hand, at the connecting portion between the main fuel nozzle 13 and the bleed pipe 12, there is a shoulder portion 28 that can come into contact with the step portion 23.
are protruded around the entire circumference. Also, bleed pipe 1
At the lower end of 2, a flange portion 29 facing the step portion 25 is provided.
are provided around the entire circumference. On the other hand, at the bottom of the main fuel jet 14, there is a spring receiving seat 30 facing downward.
A small diameter cylindrical part 31 is concentrically protruded through the small diameter cylindrical part 31, and at the lower end of this small diameter cylindrical part 31, a locking part 32 slightly protruding outward in the radial direction extends around the entire circumference or in a straight line. It is installed protrudingly.

Further, a large diameter fitting hole 34 is provided in the lower part of the low speed fuel passage 17 via a conical portion 33 which becomes larger in diameter as it goes downward. 18 is fitted. Moreover, movement of the low-speed fuel jet 18 into the low-speed fuel passage 17 is restricted by the conical portion 33. On the other hand, a small-diameter cylindrical portion 36 is concentrically protruded from the lower part of the low-speed fuel jet 18 via a spring receiving seat 35 facing downward.

The state in which the main fuel jet 14 and the low-speed fuel jet 18 are fitted into the holder 11 is maintained by a single coil spring 37 interposed between the main fuel jet 14 and the low-speed fuel jet 18 and the bottom 4a of the float chamber body 4. That is, the coil spring 37 urges the main fuel jet 14, bleed pipe 12, and main fuel nozzle 13 upward, and the shoulder 28 presses against the stepped part 23, causing the main fuel nozzle 13 and the bleed pipe 12 to enter the holder 11. At the same time, the main fuel jet 14 is held in pressure contact with the lower end of the bleed pipe 12 in the holder 11. At the same time, the low-speed fuel nozzle 18 is also urged upward by the coil spring 37 and is held in the holder 11 in pressure contact with the conical portion 33 .

Below the main fuel jet 14, the bottom 4a of the float chamber body 4 has an upwardly raised protuberance 3.
8 is provided, and the upper part of this raised part 38 is provided with an inclined surface 39 that slopes downward toward the center;
A circular recess 40 recessed downward is provided at the center of the inclined surface 39. The inner diameter of this circular recess 40 is set to be slightly larger than the diameter of the coil spring 37.

Referring also to FIG. 4, the coil spring 37 is
It is disposed approximately concentrically with the main fuel jet 14, and its upper portion is inserted into the small diameter cylindrical portion 31 of the main fuel jet 14 and abuts against the spring seat 30.
The coil spring 37 is fitted at its lower part into the circular recess 40 and is interposed between the main fuel jet 14 and the bottom 4a of the float chamber body 4. Moreover, the upper end of the coil spring 37, i.e., the end on the main fuel jet 14 side, extends towards the low speed fuel jet 18 and has a circular engagement portion 41 formed at its tip.
The coil spring 37 exerts a spring force in a direction urging the main fuel jet 14 and the low speed fuel jet 18 upward.

Referring again to FIGS. 1 and 2, within the float chamber 6 is a float 42 that surrounds the holder 11.
A float valve 43, which opens and closes in response to the float 42, is inserted into the guide cylinder portion 44. On the other hand, a fuel supply passage 45 is bored in the carburetor main body 3, and a fuel supply pipe 46 communicating with the fuel supply passage 45 is integrally protruded, and a valve hole is opened and closed by a float valve 43. 47
is bored in communication with the fuel supply passage 45. In addition, a fuel tank 4 is provided in the middle of the fuel supply passage 45.
8 is interposed, and this fuel tank 48 is opened and closed by a lever 49.

Next, to explain the operation of this embodiment, the main fuel nozzle 13, bleed pipe 12, main fuel jet 14 and low speed fuel jet 18 are connected to the holder 11
When installing the coil spring 37, first, with the carburetor body 3 and float chamber body 4 separated, one end of the coil spring 37 is inserted into the small diameter cylindrical portion 31 of the main fuel jet 14, and the engaging portion is 41 is inserted into the small diameter cylindrical portion 36 of the low speed fuel jet 18 and engaged.
At this time, the vicinity of one end of the coil spring 37 is
2, the coil spring 37 will not easily separate from the main fuel jet 14. Next, in this state, the main fuel nozzle 13 and the bleed pipe 12 are fitted into the small diameter part 22, the medium diameter part 24, and the water diameter part 26, and the main fuel jet 1
4 into the large diameter portion 26, and further fit the low speed fuel jet 18 into the fitting hole 34 of the low speed fuel passage 17. After that, the float valve 43 and the float 4
2 etc. in the predetermined position, float chamber body 4
is connected to the carburetor body 3. At this time, since the bottom portion 4a of the float chamber body 4 is provided with an inclined surface 39 and a circular recess 40, the coil spring 37 is guided by the inclined surface 39 and fitted into the circular recess 40.

Therefore, the coil spring 37 is interposed between the main fuel jet 14 and the bottom 4a of the float chamber body 4 with its axes aligned without shifting its mounting position. The spring force of the coil spring 37 acts along the axis. As a result, a pressing force is applied upward along the axis to the main fuel jet 14, bleed pipe 12, and main fuel nozzle 13, and the fitted state is maintained. Moreover, since the engaging portion 41 at the end of the coil spring 37 engages with the low-speed fuel jet 18, the pressing force of the coil spring 37 acts upwardly on the low-speed fuel jet 18 as well. The state of fitting into the holder 11 is maintained.

In the above embodiment, a carburetor in which the bleed pipe 12 and the main fuel jet 14 are separated has been described, but the present invention has a structure in which the bleed pipe 12 and the main fuel jet 14 are separated.
It is also possible to implement a vaporizer that is integrated with 4.

As described above, according to the present invention, a float chamber body for forming a float chamber is coupled to the lower part of a carburetor body having an intake passage, and a holder extending toward the bottom of the float chamber body is integrated. In the carburetor, a pair of fuel jets are installed in parallel and are fitted in parallel to the lower end of the holder located below the fuel oil surface, and a pair of fuel jets communicating with a fuel nozzle opened in the intake passage are fitted in parallel to each other, and one fuel jet is connected to the other fuel jet. A single coil spring disposed substantially concentrically is interposed between the one fuel jet and the bottom of the float chamber body, and the coil spring extends laterally from one end. Because the spring force of the coil spring is used to hold both fuel jets at the lower end of the holder, only one coil spring is used to hold both fuel jets in the holder. Nevertheless, there is no need to specially install a common spring receiving member between the one coil spring and both fuel jets, or to make both fuel jets into a single part, and therefore, the coil spring is the only individual part. This combined with the fact that the overall structure is simple, contributes to cost reduction and improved assembly efficiency.Furthermore, when changing the effective diameter of one of the fuel jets, it is possible to It is easy to deal with this as it is sufficient to replace only one of the fuel jets, and the cost can also be reduced. Moreover, the diameter of the coil spring can be determined according to the size of one of the fuel jets, and there is no need to make it have a particularly large diameter corresponding to the sizes of both fuel jets, so it can be used even in a narrow float chamber. Coil springs can be easily installed.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional view, FIG. 2 is a sectional view taken along the line -- in FIG. 1, and FIG. FIG. 4 is a sectional view taken along the - line in FIG. 3. DESCRIPTION OF SYMBOLS 1... Carburetor, 2... Intake path, 3... Carburetor body, 4... Float body, 4a... Bottom, 11...
...Holder, 13...Main fuel nozzle, 14...Main fuel jet, 18...Low speed fuel jet, 20...
...Low speed fuel nozzle, 37...Coil spring, 41...
...Engagement part, l...Fuel oil level.

Claims (1)

[Scope of utility model registration request] A float chamber body 4 for forming a float chamber 6 is coupled to the lower part of the carburetor main body 3 having the intake passage 2, and a holder 11 extending toward the bottom 4a of the float chamber body 4 is integrally provided. In the carburetor, a pair of fuel jets 14 and 18 communicating with fuel nozzles 13 and 20 opened to the intake passage 2 are fitted in parallel to the lower end of the holder 11 located below the fuel oil level l, A single coil spring 37 disposed approximately concentrically with respect to one fuel jet 14 is interposed between the one fuel jet 14 and the bottom 4a of the float chamber body 4, and the coil spring 37 The engaging portion 41 extending laterally from one end is engaged with the other fuel jet 18,
A carburetor characterized in that both fuel jets 14 and 18 are held at the lower end of the holder 11 by the spring force of the coil spring 37.