1. Field of the Invention
This invention relates to an engine of a remote control model, particularly to an improvement of its carburetor.
2. Description of the Prior Art
As shown in
However, with the throttle 12 and the second needle 13 installed in one side of the axial hole 11, and the guiding sleeve 14 and the third needle 15 installed in the other side, there are three sets of progressive tolerance possibly happening at two sides of the axial hole 11 respectively while assembling owing to too many components closely assembled together, apt to downgrade precision. As shown in
The objective of this invention is to offer a carburetor of a remote control model.
The carburetor has a main body axially bored with an axial hole that is installed with a throttle and a second needle in its one side and provided with a female-threaded section formed at a certain portion of its other side for engaging with a male-threaded section of an adjustment valve. The adjustment valve is provided with a fuel entering passage formed axially with a dead end, and an injection nozzle formed at the end corresponding to and for a needle valve of the second needle to move to and fro therein. And, the adjustment valve is directly installed in the axial hole without being accompanied with other components, effective to lower progressive tolerance between the injection nozzle and the needle valve to provide uniform fuel injection.
This invention is better understood by referring to the accompanying drawings, wherein:
As shown in
The main body 20 is bored axially with an axial hole 21.
The throttle 30 is installed movable axially in one side of the main body 20 to be therein, provided with a throttle hole 31 bored axially. The throttle hole 31 is provided with a female-threaded section 311 formed around its outside portion, and a concave conical surface 312 formed at its one end inside the axial hole 21. The throttle 30 is combined with an operating bar 32, which is fixed around an outer end of the throttle 30.
The second needle 40 is provided with a male-threaded section 41 formed near its outer end for engaging with the female-threaded section 311 of the throttle hole 31, a needle valve 42 formed by tapering at its inner side in the axial hole 21, and an operating portion 43 formed at its outer end.
The adjustment valve 50 is provided with a male-threaded section 51 formed around its intermediate portion for engaging with a female-threaded section 211 formed around the intermediate portion of the axial hole 21. The adjustment valve 50 is also provided with a fuel entering passage 52 formed axially with a dead end, a injection nozzle 53 formed at the other end of the fuel entering passage 52 to correspond with the needle valve 42, and a convex conical surface 531 formed around the injection nozzle 53 to face to the concave conical surface 312. The injection nozzle 53 is located at the center of the convex conical surface 312 for being inserted with the needle valve 42. Slightly inward the end of the adjustment valve 50, opposite to the injection nozzle 53, is formed with an annular groove 54, which is symmetrically bored with four holes 541 spaced apart equidistantly for communicating with the fuel entering passage 52. A threaded hole 212 is bored vertically on the main body 20 through the axial hole 21, for corresponding to the annular groove 54. Further, there is an annular groove 55 cut around slightly inward two ends of the adjustment valve 50 respectively, for being fitted with a sealing element 56. In addition, the adjustment valve 50 is provided with an operating portion 57 formed concave at its other end opposite to the injection nozzle 53. The annular grooves 55 are tightly sealed with the O-shaped sealing elements 56 to prevent fuel from leaking out.
The main fuel needle 60 is fixedly engaged with the threaded hole 212, provided with a fuel inlet nozzle 61 positioned aside for connecting with a fuel hose to a fuel tank (not shown in Figures), so as to supply fuel to enter the annular groove 54 and then, through the holes 541 to the fuel entering passage 52
In using, as shown in
Moreover, as shown in
The advantages of the invention are described below as can be seen from the foresaid description.
As the adjustment valve 50 is directly engaged with the axial hole 21 without being installed with any extra component, it is helpful to lessen progressive tolerance created while assembling, so as to keep the gap between the needle valve 42 and the injection nozzle 53 spaced uniformly to provide an even fuel injection. And, the mixing chamber 70 formed between the convex conical surface 531 of the adjustment valve 50 and the concave conical surface 312 is enlarged to provide a bigger space to mix fuel with air.
While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.