Fuel metering rod for carburetor and carburetor

Abstract

The present invention relates to a fuel metering rod for a carburetor and a carburetor, wherein the fuel metering rod (1) comprises a first cylinder (101), wherein the first cylinder (101) is provided with an inclined surface. The first cylinder of the fuel metering rod of the present invention is provided with an inclined surface, so that the functions of the auxiliary metering hole, transitional metering hole, main metering hole, and mixture ratio screw on the traditional carburetor are all gathered on the fuel metering rod, and the traditional auxiliary oil hole design, auxiliary oil hole screw design, transitional oil hole design, main metering hole design, and main oil hole screw design are abandoned, so that the carburetor does not need to replace the metering hole screw and frequently adjust the mixture ratio screw and the oil needle height according to changes in environmental factors such as altitude, temperature, and humidity, but achieves the purpose of intelligently adjusting the oil-gas mixture ratio through the characteristics of atmospheric pressure and the mutual cooperation between the fuel generated by the inclined surface on the fuel metering rod and the atmosphere of different densities.

Description

Technical Field

[0001] The invention relates to the technical field of engines, and in particular to a fuel metering rod for a carburetor and a carburetor. Background Art

[0002] As an important part of vehicles such as motorcycles, the carburetor is mainly used to mix a certain proportion of fuel and air and atomize it. The carburetor can automatically mix the corresponding concentration of mixed gas according to the requirements of different working conditions of the engine, and output the corresponding amount of mixed gas for the engine to burn and do work.

[0003] Traditional carburetors are generally divided into plunger type and vacuum membrane type, each with its own advantages and disadvantages. The biggest advantage of plunger type carburetors is that they have sensitive throttle response, simple structure, and stable operation. They are also the most commonly used type of carburetors in the current domestic motorcycle competition field. The biggest advantage of vacuum membrane carburetors is that they can adapt to the operation of rapid throttle opening. Due to the two-way design of the throttle and the throttle valve, there is a certain delay in the opening movement between them. The opening speed of the throttle valve always lags behind the opening speed of the throttle valve. When the throttle valve is opened quickly, the effective negative pressure value is still maintained behind the throttle valve. During the delayed opening of the throttle valve, the fuel completes a smooth transition from the idle oil hole and the transition oil hole to the main oil hole, so that there will be no lack of oil or flameout due to rapid opening of the throttle valve.

[0004] However, both plunger carburetors and vacuum membrane carburetors have a common technical problem, that is, they must perform tedious replacement of the main and auxiliary metering orifice screws and the oil needle model, and adjustment of the oil needle height and the mixture ratio at any time and place according to changes in local environmental factors such as altitude and temperature. Summary of the invention

[0005] In order to solve the technical defects and shortcomings of the prior art, the present invention provides a fuel metering rod for a carburetor and a carburetor.

[0006] Specifically, an embodiment of the present invention provides a fuel metering rod for a carburetor, wherein the fuel metering rod comprises a first cylinder, wherein an inclined surface is provided on the first cylinder.

[0007] In one embodiment of the present invention, the inclined surface includes a straight line inclined surface or an arc inclined surface.

[0008] In one embodiment of the present invention, the slope of the tangent line of the arc slope from the first end to the second end of the first cylinder gradually increases.

[0009] An embodiment of the present invention further provides a carburetor, comprising the fuel metering rod described in any one of the above items.

[0010] In one embodiment of the present invention, it also includes an oil delivery tunnel, a plate valve and a carburetor body, the carburetor body includes a float chamber, and the fuel metering rod also includes a connector, wherein:

[0011] The oil transport tunnel is provided with a circular through hole, and the diameter of the fuel metering rod is less than or equal to the diameter of the circular through hole, the connecting body is fixedly arranged at the first end of the first cylinder, the first cylinder of the fuel metering rod is connected to the plate valve through the connecting body, and the fuel metering rod moves from the first end to the second end of the first cylinder through the circular through hole to the float chamber.

[0012] In one embodiment of the present invention, the plate valve comprises a first plate valve body, a rotating boss structure, a first spring, and a slot structure, wherein the rotating boss structure, the first spring, and the slot structure are coaxially arranged in the cavity of the first plate valve body, and the first end of the first spring is fixedly connected to the cavity of the first plate valve body, the second end of the first spring is fixedly connected to the rotating boss structure, and the rotating boss structure is fixedly arranged in the cavity of the first plate valve body, wherein:

[0013] The rotating boss structure includes a first cavity structure and a plurality of bosses, the slot structure includes a first base structure and a plurality of groove structures, the number of the bosses is less than or equal to the number of the groove structures, and the first cavity structure passes through the first base structure so that the boss is inserted into the groove structure, and the fuel metering rod is connected to the first cavity structure through the connector.

[0014] In one embodiment of the present invention, the plate valve includes a second plate valve body, a metering rod anti-rotation column, a first baffle, a second spring, a metering rod positioning column, a first card, a second baffle, and a buckle. The metering rod anti-rotation column, the first baffle, the second spring, the metering rod positioning column, the first card, the second baffle and the buckle are coaxially arranged in the cavity of the second plate valve body in sequence. The metering rod anti-rotation column is fixedly arranged in the cavity of the second plate valve body. The metering rod anti-rotation column includes a second base structure and a second cylinder. The metering rod positioning column is connected to the inner cavity of the second plate valve body by a thread. The first end of the metering rod positioning column is provided with a first blind hole, and the second end of the metering rod positioning column is provided with a second blind hole, wherein,

[0015] The fuel metering rod is connected to the second base structure through the connecting body, the first baffle and the second spring are sequentially sleeved on the second cylinder, the first end of the second cylinder is fixedly set on the second base structure, the second end of the second cylinder is set in the first blind hole of the metering rod positioning column, the first card is clamped on the groove of the second cylinder, the second baffle and the buckle are sequentially sleeved on the second end of the metering rod positioning column, and the buckle is also set on the groove of the second plate valve body.

[0016] In one embodiment of the present invention, it also includes a second card, a third spring and an adjusting rod. The adjusting rod passes through the through hole of the second plate valve body and is movably arranged in the second blind hole of the metering rod positioning column. The second card and the third spring are sequentially sleeved on the adjusting rod, and the second card is clamped on the groove of the adjusting rod.

[0017] In one embodiment of the present invention, it also includes a plurality of fuel auxiliary pumps, and the carburetor body also includes an air intake chamber, wherein the fuel auxiliary pump is connected to the air intake chamber and the float chamber, and the fuel auxiliary pump includes a first needle valve and a first oil pipe, the first needle valve is movably arranged at the oil inlet end of the air intake chamber, and is used to adjust the opening size of the oil inlet end entering the air intake chamber, the first end of the first oil pipe is connected to the float chamber, and the second end of the first oil pipe is connected to the oil inlet end of the air intake chamber.

[0018] In one embodiment of the present invention, it also includes a second needle valve and a second oil pipe. The carburetor body also includes a mixing chamber. The second needle valve is movably arranged in a connecting hole of the first oil inlet end of the mixing chamber to adjust the opening size of the first oil inlet end. The first end of the second oil pipe is connected to the float chamber, and the second end of the second oil pipe is connected to the first oil inlet end.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The first cylinder of the fuel metering rod of the present invention is provided with an inclined surface, so that the functions of the auxiliary metering hole, transition metering hole, main metering hole, mixture ratio screw and the like on the traditional carburetor are all gathered on the fuel metering rod, and the traditional auxiliary oil hole design, auxiliary oil hole screw design, transition oil hole design, main oil hole design and main oil hole screw design are abandoned. During the entire operation of the carburetor, the gap at the injection end of the oil delivery tunnel is always smaller than the gap of the circular through hole at the oil inlet end of the oil delivery tunnel, so that the atomization effect of the fuel is better, the engine combustion work is better, the engine exhaust gas emission is less, and the engine consumes less fuel. At the same time, the carburetor does not need to replace the metering hole screw and the oil needle model and frequently adjust the mixture ratio screw and the oil needle height according to changes in environmental factors such as altitude, temperature and humidity, but achieves the purpose of intelligently adjusting the oil-gas mixture ratio through the characteristics of atmospheric pressure and the fuel generated by the inclined surface on the fuel metering rod and the atmosphere of different densities. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structure of a fuel metering rod provided by an embodiment of the present invention;

[0022] Figure 2 A schematic structural diagram of a plunger type carburetor provided by an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of the structure of a vacuum mode carburetor provided by an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of the structure of a plunger-type carburetor during startup provided by an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of the structure of a plunger-type carburetor at idle speed provided by an embodiment of the present invention;

[0026] Figure 6a A schematic diagram of the structure of a plunger-type carburetor at medium speed provided by an embodiment of the present invention;

[0027] Figure 6b A schematic structural diagram of a vacuum mode carburetor at medium speed provided by an embodiment of the present invention;

[0028] Figure 7 A schematic diagram of the structure of a plunger-type carburetor at full speed provided by an embodiment of the present invention;

[0029] Figure 8 A schematic diagram of the structure of another fuel metering rod provided by an embodiment of the present invention;

[0030] Fig. 9 A schematic diagram of the structure of another fuel metering rod provided in an embodiment of the present invention;

[0031] Fig.10 A schematic diagram of the structure of another fuel metering rod provided by an embodiment of the present invention;

[0032] Fig.11 A structural schematic diagram of a carburetor provided by an embodiment of the present invention;

[0033] Fig.12 A schematic structural diagram of an internally adjustable plate valve provided in an embodiment of the present invention;

[0034] Fig.13 A schematic diagram of the exploded structure of an internally adjustable plate valve provided in an embodiment of the present invention;

[0035] Fig.14 A schematic structural diagram of an externally adjustable plate valve provided in an embodiment of the present invention;

[0036] Fig.15 A schematic diagram of the exploded structure of an externally adjustable plate valve provided in an embodiment of the present invention;

[0037] Fig.16 A schematic diagram of the structure of a second card, a third spring and an adjustment rod provided in an embodiment of the present invention;

[0038] Fig.17 A schematic diagram of the structure of a needle valve provided in an embodiment of the present invention;

[0039] Fig.18 A schematic structural diagram of another carburetor provided in an embodiment of the present invention.

[0040] Description of reference numerals:

[0041] 1 fuel metering rod; 2 oil delivery tunnel; 3 plate valve; 4 carburetor body; 5 second card; 6 third spring; 7 adjustment rod; 9 second needle valve; 10 second oil delivery pipe; 11 choke; 12 oil float; 13 oil inlet needle valve; 14 fuel inlet hole; 15 float chamber air pressure balance hole; 16 idle screw; 101 first cylinder; 102 connector; 301 first plate valve body; 302 rotating boss structure; 303 first spring; 304 card slot structure; 305 second plate valve body; 306 metering rod anti-rotation column; 307 first baffle; 308 The second spring; 309 the metering rod positioning column; 3010 the first card; 3011 the second baffle; 3012 the buckle; 401 the float chamber; 402 the air inlet chamber; 403 the mixing chamber; 801 the first needle valve; 802 the first oil pipeline; 3021 the first cavity structure; 3022 the boss; 3041 the first base structure; 3042 the groove structure; 3061 the second base structure; 3062 the second cylinder; 3091 the first blind hole; 3092 the second blind hole; 30612 the anti-rotation rib; 4021 the oil inlet end; 4031 the first oil inlet end. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0043] It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or directly coupled to the other element, or intervening elements may be present. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements. The same reference numerals refer to the same elements throughout.

[0044] For ease of description, spatially relative terms, such as "under," "below," "below," "above," "above," etc., may be used herein to describe the relationship of one element or feature to another element or feature as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation described in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as "under" or "below" other elements or features will subsequently be positioned as "above" the other elements or features. Thus, the example term "under" may include both "above" and "below" orientations. The device may be otherwise positioned (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein interpreted accordingly.

[0045] In this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0046] Embodiment 1

[0047] See also Figure 1 , Figure 1 A schematic diagram of the structure of a fuel metering rod provided in an embodiment of the present invention. This embodiment provides a fuel metering rod for a carburetor, wherein the fuel metering rod 1 comprises a first cylinder 101, wherein the first cylinder 101 is provided with an inclined surface.

[0048] An inclined surface is arranged on the first cylinder of the fuel metering rod of the present invention, so that the functions of the auxiliary metering hole, transitional metering hole, main metering hole, mixture ratio screw and the like on the traditional carburetor are all gathered on the fuel metering rod, and the traditional auxiliary oil hole design, auxiliary oil hole screw design, transitional oil hole design, main oil hole design and main oil hole screw design are abandoned. As a result, the carburetor no longer needs to replace the metering hole screw and frequently adjust the mixture ratio screw and the oil needle height according to changes in environmental factors such as altitude, temperature and humidity. Instead, the purpose of intelligently adjusting the oil-gas mixture ratio is achieved through the characteristics of atmospheric pressure and the cooperation between the fuel generated by the inclined surface on the fuel metering rod and the atmosphere of different densities.

[0049] All carburetors work under atmospheric pressure. Atmospheric pressure is a powerful force that exerts pressure on everything. Carburetors also utilize the various physical properties of the atmosphere to mix the fuel and atmosphere and transmit them to the cylinder for combustion and work. The work of the engine cylinder is achieved by the full combustion of oxygen and fuel in the atmosphere, which converts heat energy into kinetic energy. In this process, air and fuel must be mixed in a certain proportion in order for the fuel to burn and do work. This proportion is the mixture ratio of air and fuel, also called the air-fuel ratio. This air-fuel ratio is not always constant in actual engine work, and it will be adjusted according to different engine speeds to achieve effective power output.

[0050] Theoretically, 14.7 kg of air is required to completely burn 1 kg of gasoline. The air-fuel ratio is represented by the letter a, so the air-fuel ratio a = weight of air ÷ weight of fuel. The theoretical air-fuel ratio for complete combustion is: 14.7:1 = 14.7, the theoretical minimum limit air-fuel ratio is: 7:1 = 7, and the theoretical maximum limit air-fuel ratio is: 20:1 = 20. Therefore, this embodiment uses 14.7 as the reference node. Numbers below 14.7 are called richer air-fuel ratios, and vice versa, they are called leaner air-fuel ratios.

[0051] In actual use, according to the engine's work requirements, the following air-fuel ratios can be summarized:

[0052] 1. When the engine is started, the carburetor should provide a relatively rich mixture of a=6.9, and sometimes a super-special mixture of a=3. 2. When the engine is idling, the carburetor should provide a relatively rich mixture of a=10~12.4. 3. When the engine is running at medium speed, the carburetor should provide a relatively standard mixture of a=13~15. 4. When the engine is running at full speed, the carburetor should provide a relatively rich mixture of a=12.6~13.5.

[0053] Therefore, different parts of the carburetor need to be adjusted to get close to the air-fuel ratio data at different speeds. Please refer to Figure 2 and Figure 3The fuel supply system of a traditional carburetor is generally composed of a choke, a mixture ratio screw, an idle screw, a secondary oil metering hole, a transition oil hole, a main oil metering hole, a fuel needle, a throttle valve, etc., which work in coordination with each other. The working principles of each part are as follows:

[0054] 1. See Figure 4 When starting, especially when the temperature is low, you need to pull up the "choke". There are two designs of "choke", one is to isolate more air, and the other is to release more fuel. No matter which one, the ultimate goal is to reduce the air-fuel ratio number. The lower the temperature, the smaller the data required, that is, the mixture becomes richer. Then the "choke" works with the auxiliary oil metering hole and the throttle valve clearance to produce the air-fuel ratio data between 3 and 6.9 required by the engine during cold start.

[0055] 2. See Figure 5 At idle, the engine has been preheated, the fuel has good evaporation during the transmission process, and the "choke" has been closed. At this time, the secondary oil metering hole, throttle valve clearance and mixture ratio screw work together to produce the air-fuel ratio data between 10 and 12.4 required by the engine at idle.

[0056] 3. See Figure 6a and Figure 6b At medium speed, the auxiliary oil metering hole only supplies a small amount of oil, and the mixture ratio screw has little effect. It is mainly coordinated by the main oil metering hole, oil needle and throttle valve. It should be noted here that there is a transition oil hole in the vacuum membrane carburetor. This transition oil hole mainly provides the fuel required by the engine from idle to medium speed, so as to achieve a better transition and ultimately produce the air-fuel ratio data between 13 and 15 required by the engine at medium speed.

[0057] 4. See Figure 7 At full speed, the secondary metering hole and the transition oil hole almost stop supplying oil, the mixture ratio screw is meaningless, and the oil needle and the throttle valve are also meaningless. Only the main metering hole and the main metering hole screw work, thus generating the air-fuel ratio data between 12.6 and 13.5 required by the engine at full speed.

[0058] In one embodiment of the present invention, the inclined surface of the first cylinder 101 may be a straight inclined surface or an arc inclined surface.

[0059] See also Figure 8 , Figure 8The inclined plane in is a straight line inclined plane, that is, a straight line inclined plane is set from the first end to the second end of the first cylinder 101, wherein the first end of the first cylinder 101 is the end away from the float chamber 401 of the carburetor, and the second end of the first cylinder 101 is the end close to the float chamber 401. The greater the inclination of the straight line inclined plane (that is, the smaller the angle between the straight line inclined plane and the X-axis), the more fuel the fuel metering rod 1 will provide at high speed and full speed of the engine, thereby reducing the air-fuel ratio data. This function is equivalent to the screw of the main oil metering hole in the traditional carburetor. On the contrary, if the inclination of the straight line inclined plane is smaller (that is, the angle between the straight line inclined plane and the X-axis is larger), the metering rod will provide relatively less fuel at high speed and full speed of the engine, thereby increasing the air-fuel ratio data. Please refer to Fig. 9 , Fig. 9 There are metering rod slopes with different slopes, wherein the slopes of slopes A, B, C and D gradually increase, wherein the straight slope from the first end to the second end of the first cylinder 101 may include a start-up and idle zone, a low speed to medium and high speed working zone and a high speed to full speed working zone, so the gap between the fuel metering rod and the outlet end of the oil transport tunnel can be adjusted by controlling the height of the fuel metering rod in the oil transport tunnel to achieve the required fuel state from start-up to full speed operation. And the greater the slope of the straight slope, the greater the change in its injection amount when transitioning from the start-up and idle zone to the high speed to full speed working zone.

[0060] Preferably, the float chamber 401 may be made of a transparent or translucent material so that the situation inside the float chamber can be visually seen.

[0061] It should be noted that, according to the requirements of different engine working conditions, the length, diameter, inclination of the straight slope and the setting of the working area from start-up to full speed of the fuel metering rod are different, and no specific limitation is made here. Those skilled in the art can easily process and manufacture according to actual conditions based on this embodiment.

[0062] See also Figure 1 , Figure 1 The inclined surface in is an arc inclined surface, that is, an inclined surface with an arc is provided from the first end to the second end of the first cylinder 101, and the slope of the tangent line of the arc inclined surface from the first end to the second end of the first cylinder 101 gradually increases. The entire arc inclined surface is composed of a curved surface from the first end to the second end, and the slope of the curved surface at the second end of the arc inclined surface is infinitely close to 90 degrees, thereby satisfying the fuel supply of the engine at different speed periods. Please refer to Fig. 9 , Fig. 9There are metering rod slopes with different curvatures, wherein the curvatures of slopes C-1, C-2, C-3 and C-4 gradually increase, wherein the arc slope from the first end to the second end of the first cylinder 101 may include a starting and idling area, a low speed to medium and high speed working area and a high speed to full speed working area, so the gap between the fuel metering rod and the outlet end of the oil delivery tunnel can be adjusted by controlling the height of the fuel metering rod in the oil delivery tunnel to achieve the required fuel state from starting to full speed operation, the greater the curvature of the arc slope, the more fuel the fuel metering rod will provide when the engine changes from a low speed area to a medium speed area, thereby reducing the air-fuel ratio data, which is equivalent to the secondary oil metering hole, the secondary oil metering hole screw and the transition oil hole in the traditional carburetor. On the contrary, if the curvature is smaller, the metering rod will provide relatively less fuel when the engine changes from a low speed area to a medium speed area, thereby increasing the air-fuel ratio data.

[0063] It should be noted that, according to the requirements of different engine working states, the length, diameter, slope change rate of the arc slope and the setting of the working area from start-up to full speed of the fuel metering rod are all different. No specific limitation is made here. Those skilled in the art can easily process and manufacture according to actual conditions based on this embodiment.

[0064] See also Fig.10 The fuel metering rod 1 of this embodiment also includes a buffer zone, that is, Fig.10 Area A in the diagram is a cylinder without an inclined surface. This area is the idle speed adjustment area. The fuel metering rod 1 with a buffer zone is suitable for the carburetor of a four-stroke engine because the four-stroke engine requires more precise fuel supply, especially between the idle speed and the 1 / 4 opening of the plate valve. Therefore, a buffer zone is set on the fuel metering rod 1.

[0065] The greater the negative pressure in the carburetor throat, the more fuel will be ejected. Even at the same plate valve opening, the lower the atmospheric pressure, the less fuel will be ejected, and the higher the atmospheric pressure, the more fuel will be ejected. The fuel supply is automatically adjusted according to the engine's needs in combination with the atmospheric pressure and temperature at the time. The atmospheric pressure ranges from 67.24kpa to 101.3kpa, which is equivalent to an altitude span of 3000-0 meters and a temperature from 20°C to -20°C. The oxygen content in the atmosphere will become richer as the temperature drops. The fuel metering rod in this embodiment can intelligently mix a reasonable air-fuel ratio according to the negative pressure value in the carburetor throat, so that the carburetor will no longer be sensitive to altitude and temperature.

[0066] The fuel metering rod of this embodiment uses the same fuel delivery pipeline from idle to full speed, that is, the pipeline matched between the fuel metering rod and the oil delivery tunnel. Under any opening amount of the plate valve, the metering rod is designed as a smooth inclined surface, so that the oil inlet gap of the pipeline is always larger than the oil outlet gap. In addition, when the fluid flows from one space to another narrow space, the flow rate will be accelerated, that is, the fuel injection effect will be better and the atomization will be more sufficient. Secondly, at idle, the pipeline is already full of fuel. Therefore, when the plate valve is suddenly opened at idle, that is, when the throttle is opened suddenly, the engine will not have a momentary oil shortage phenomenon. In addition, the fuel metering rod replaces the auxiliary oil hole, transition oil hole, main oil hole and other designs, making the oil delivery channel more concise, and satisfactory effects can be achieved in both violent acceleration and throttle response. In addition, due to the improved atomization effect and improved air mobility, the power of the engine is improved, thereby achieving the purpose of more fuel saving and environmental protection.

[0067] The embodiment of the present invention further provides a carburetor based on the fuel metering rod provided in the above embodiment, see Fig.12 The carburetor includes the fuel metering rod 1 described in the above embodiment, and also includes an oil delivery tunnel 2, a plate valve 3 and a carburetor body 4. The carburetor body 4 includes a float chamber 401, an air intake chamber 402 and a mixing chamber 403. The fuel metering rod 1 also includes a connector 102, wherein:

[0068] The oil transportation tunnel 2 is provided with a circular through hole, and the diameter of the first cylinder 101 of the fuel metering rod is less than or equal to the diameter of the circular through hole of the oil transportation tunnel 2, the connecting body 102 is fixedly arranged at the first end of the first cylinder 101, the first cylinder 101 of the fuel metering rod 1 is connected to the plate valve 3 through the connecting body 102, and the fuel metering rod 1 moves from the first end to the second end of the first cylinder 101 through the circular through hole to the float chamber 401.

[0069] The oil delivery tunnel 2 connects the float chamber 401 with the mixing chamber 403. The float chamber 401 is used to store the fuel delivered by the fuel pump to ensure the supply of fuel. The air inlet chamber 402 is used to supply air. The air outlet of the mixing chamber 403 is connected to the cylinder of the engine. The mixing chamber 403 passes the mist fuel particles and air mixture into the cylinder of the engine.

[0070] Preferably, the diameter of the first cylinder 101 of the fuel metering rod is 95% to 100% of the diameter of the circular through hole of the oil delivery tunnel 2 .

[0071] The first cylinder 101 matches the oil tunnel 2, and the first cylinder 101 of the fuel metering rod 1 can move up and down along the axial direction in the oil tunnel 2, so that a gap is generated according to the cooperation between the inclined surface of the first cylinder 101 and the oil tunnel 2. When the first cylinder 101 moves upward along the axial direction, the gap generated by the cooperation between the inclined surface of the first cylinder 101 and the oil tunnel 2 becomes larger and larger, and the fuel that can be provided to the engine will become more and more. By adjusting the gap generated by the cooperation between the first cylinder 101 and the oil tunnel 2, the engine can be started from the idle zone, from the idle zone to the low speed zone, and finally to the full speed working zone.

[0072] Preferably, the connecting body 102 is a threaded connecting body, so that the first cylinder 101 is threadedly connected to the plate valve 3 through the connecting body 102 .

[0073] Because the change in the height position of the fuel metering rod 1 will very sensitively affect the mixing ratio from idle to 1 / 4, the traditional slot design is not applicable and a more sophisticated adjustment method is required. The present embodiment utilizes threads to achieve the adjustment of the height position of the fuel metering rod 1. According to aerodynamics and a better atomization effect, the inclined surface of the metering rod must always face the side of the engine when working. Therefore, it is also necessary to return the inclined surface to its original position after each height and low adjustment.

[0074] The plate valve 3 is mainly used to adjust the position of the fuel metering rod 1 along the axial direction. The plate valve 3 includes two types, one is an internally adjustable plate valve, and the other is an externally adjustable plate valve. The purpose of adjusting the position of the fuel metering rod 1 along the axial direction can be achieved by using the internally adjustable plate valve or the externally adjustable plate valve.

[0075] See also Fig.12 and Fig.13The internal adjustment plate valve comprises a first plate valve body 301, a rotating boss structure 302, a first spring 303, and a slot structure 304. The rotating boss structure 302, the first spring 303 and the slot structure 304 are coaxially arranged in the cavity of the first plate valve body 301, and the first end of the first spring 303 is fixedly connected to the inner wall in the cavity of the first plate valve body 301, and the second end of the first spring 303 is fixedly connected to the top wall of the rotating boss structure 302, so that the first spring 303 can move between the inner wall in the cavity of the first plate valve body 301 and the top wall of the rotating boss structure 302, and the rotating boss structure 302 is fixedly arranged in the cavity of the first plate valve body 301, wherein the rotating boss structure 302 comprises a first cavity structure 3021 and a plurality of bosses 3022, a plurality of bosses 3022 are arranged on the first cavity structure 3021, the first cavity structure 3021 has a through hole structure, the slot structure 304 includes a first base structure 3041 and a plurality of groove structures 3042, the groove structures 3042 are arranged on the side wall of the first base structure 3041, the number of bosses 3022 is less than or equal to the number of groove structures 3042, and the first cavity structure 3021 passes through the first base structure 3041 so that the bosses 3022 are stuck in the groove structures 3042. Since the first plate valve body 301 is fixed, the bosses 3022 can be stuck in the groove structures 3042 under the action of the first spring 303, and the fuel metering rod 1 is connected to the first cavity structure 3021 through the connecting body 102.

[0076] Preferably, the inner wall of the first cavity structure 3021 is provided with internal threads, so that the fuel metering rod 1 is threadedly connected to the first cavity structure 3021 through the connecting body 102 .

[0077] Preferably, the material of the rotating boss structure 302 is nylon.

[0078] The fuel metering rod 1 of the present embodiment cooperates with the first cavity structure 3021, and a first spring 303 is fixed on the top of the first cavity structure 3021. At the same time, the first cavity structure 3021 is provided with a plurality of bosses 3022, for example, the number of bosses 3022 is 4, and each boss 3022 can be correspondingly inserted into the groove structure 3042. Under the action of the first spring 303, the boss 3022 is always in the groove structure 3042, and at this time, the side of the fuel metering rod 1 with the inclined surface facing the engine, when it is necessary to adjust the height of the fuel metering rod 1, the fuel metering rod 1 can be adjusted by twisting it counterclockwise or clockwise. Since the number of bosses 3022 is 4, the groove structure 3042 is in the form of a "cross" slot, which is equivalent to uniform rotation over a 360° circle. Four groove structures 3042 are set. It is assumed that the angle of each groove structure 3042 is 90°. Therefore, each 1 / 4 turn can be an adjustment unit, that is, 90° is a unit. No matter it is counterclockwise or clockwise, after the adjustment is completed, the fuel metering rod 1 is pushed inward to make the boss 3022 leave the groove structure 3042. At this time, the fuel metering rod 1 is rotated so that the inclined surface of the fuel metering rod 1 turns to one side of the engine, and then reset. This is equivalent to the inclined surface of the fuel metering rod 1 returning to its original position. At the same time, the height position of the fuel metering rod 1 also changes, thereby completing the adjustment. According to actual measurements, according to the British 40G thread design, the height change amplitude of the fuel metering rod 1 is 0.1524 mm for each adjustment of 1 / 4 turn, and 0.6096 mm for a full rotation.

[0079] The embodiment of the present invention does not impose any specific limitation on the number of bosses 3022 and groove structures 3042. As long as it can be ensured that the inclined surface of the fuel metering rod 1 is still facing the engine side after the position adjustment, the purpose of this embodiment can be achieved.

[0080] See also Fig.14 and Fig.15The externally adjustable plate valve comprises a second plate valve body 305, a metering rod anti-rotation column 306, a first baffle 307, a second spring 308, a metering rod positioning column 309, a first card 3010, a second baffle 3011, and a buckle 3012. The metering rod anti-rotation column 306, the first baffle 307, the second spring 308, the metering rod positioning column 309, the first card 3010, the second baffle 3011, and the buckle 3012 are coaxially arranged in the cavity of the second plate valve body 305 in sequence. The metering rod anti-rotation column 306 is fixedly arranged in the cavity of the second plate valve body 305. The metering rod anti-rotation column 306 comprises a second base structure 3061 and a second cylinder 3062. An anti-rotation rib 3061 can be arranged on the outer side wall of the second base structure 3061. 612, and a groove is correspondingly provided in the cavity of the second plate valve body 305, so that the anti-rotation rib 30612 is inserted into the groove in the cavity of the second plate valve body 305, so that the metering rod anti-rotation column 306 is fixedly provided in the cavity of the second plate valve body 305, and the metering rod positioning column 309 is connected to the inner cavity of the second plate valve body 305 by a thread, that is, an external thread is provided on the outer wall of the metering rod positioning column 309, and an internal thread is provided at the corresponding position of the inner cavity of the second plate valve body 305, so as to realize the threaded connection between the metering rod positioning column 309 and the inner cavity of the second plate valve body 305, a first blind hole 3091 is provided at the first end of the metering rod positioning column 309, and a second blind hole 3092 is provided at the second end of the metering rod positioning column 309, wherein,

[0081] The fuel metering rod 1 is connected to the second base structure 3061 through the connecting body 102, the first baffle 307 and the second spring 308 are sequentially sleeved on the second cylinder 3062, the first baffle 307 is used to block the second spring 308 and prevent it from falling onto the second base structure 3061, the first end of the second cylinder 3062 is fixedly arranged on the second base structure 3061, the first baffle 307 and the second spring 308 are both required to be arranged on the lower side of the groove of the second cylinder 3062, the second end of the second cylinder 3062 is arranged in the first blind hole of the metering rod positioning column 309, that is, the upper end part of the groove of the second cylinder 3062 is clamped The metering rod anti-rotation column 306 is inserted into the first blind hole, and then the first card 3010 is used to clamp on the groove of the second cylinder 3062, so as to realize the connection between the metering rod anti-rotation column 306 and the metering rod positioning column 309, and at the same time, the second spring 308 is restricted between the first baffle 307 and the first card 3010, the second baffle 3011 and the buckle 3012 are sequentially sleeved on the second end of the metering rod positioning column 309, and the buckle 3012 is also arranged on another groove of the second plate valve body 305. The metering rod positioning column 309 is restricted by the buckle 3012, and the buckle 3012 is elastic and is open-loop, so it can be easily installed and removed when external force is applied to it.

[0082] Preferably, the fuel metering rod 1 is threadedly connected to the second base structure 3061 through the connecting body 102 , that is, an internal thread is provided in the blind hole of the second base structure 3061 , so that the connecting body 102 is threadedly connected to the second base structure 3061 .

[0083] See also Fig.16 When using an externally adjustable plate valve to adjust the position of the fuel metering rod 1, it is also necessary to install the second card 5, the third spring 6 and the adjusting rod 7. The adjusting rod 7 passes through the through hole of the second plate valve body 305 and is movably set in the second blind hole 3092 of the metering rod positioning column 309. The second card 5 and the third spring 6 are sequentially sleeved on the adjusting rod 7, and the second card 5 is clamped on the groove of the adjusting rod 7.

[0084] The adjusting rod 7 is used to twist the metering rod positioning column 309, so as to adjust the height of the fuel metering rod 1. The carburetor body also includes a cover body, the cavity of which is used to place the plate valve, and the adjusting rod 7 needs to pass through a through hole on the cover body to be inserted into the second blind hole 3092, the third spring 6 is used to limit the movement of the adjusting rod 7 between the cover bodies, and the second card 5 is located at the position of the limiting adjusting rod 7, so that when an external force is applied to the adjusting rod 7, the adjusting rod 7 can be moved along the axial direction.

[0085] Preferably, the part of the adjusting rod 7 inserted into the second blind hole 3092 is a hexagonal adjusting rod, and the second blind hole 3092 is a hexagonal blind hole, so that when the adjusting rod 7 is inserted into the second blind hole 3092, when it is rotated clockwise or counterclockwise, the metering rod positioning column 309 can be rotated, thereby adjusting the height position of the fuel metering rod 1.

[0086] Preferably, the adjusting rod 7 is marked with scales for recording the number of rotations.

[0087] When using the external debugging plate valve for adjustment, the throttle needs to be opened to the maximum, so that the plate valve 3 rises to the highest point, and then the adjustment handle on the carburetor cover is pressed vertically to make the adjustment rod 7 embedded in the corresponding second blind hole 3092, and then counterclockwise or clockwise adjustment is performed. After the adjustment is completed, the throttle handle can be loosened. Since both sides of the nylon cylinder that fixes the metering rod have anti-rotation ribs 30612 designs, the inclined direction of the fuel metering rod 1 will not change during the above operation, and it will always face the engine side. At the same time, the adjustment rod 7 is also marked with scales for convenient recording of the number of laps or zeroing. The external debugging plate valve can be adjusted directly outside without removing the plate valve, which is convenient for use.

[0088] See also Fig.11 and Fig.17The carburetor provided in this embodiment may also include a plurality of fuel auxiliary pumps, wherein the fuel auxiliary pump is connected to the air intake chamber 402 and the float chamber 401, and the fuel auxiliary pump includes a first needle valve 801 and a first oil pipe 802. The first needle valve 801 is movably arranged at the oil inlet end 4021 of the air intake chamber 402, and is used to adjust the opening size of the oil inlet end 4021 entering the air intake chamber 402. The first end of the first oil pipe 802 is connected to the float chamber 401, and the second end of the first oil pipe 802 is connected to the oil inlet end 4021 of the air intake chamber 402.

[0089] By adjusting the axial height of the first needle valve 801, the opening size of the oil inlet end 4021 entering the air intake chamber 402 can be adjusted. At the same time, a fuel injector is connected to one side of the oil outlet end of the first needle valve 801, thereby providing fuel to the air intake chamber 402 through the fuel injector.

[0090] When the carburetor is short of oil, such as in extreme conditions, the fuel provided by the maximum gap generated by the fuel metering rod may not be able to meet the engine's work requirements, and the engine needs secondary fuel subsidies. The so-called high-speed fuel subsidy function is to set a fuel injector on the inner side of the venturi tube (throat), and this fuel injector is controlled by the first needle valve 801. Then the first needle valve 801 is connected to the intake chamber 402, and the first needle valve 801 is set to a fuel subsidy opening that can just meet the fuel subsidy required by the engine at full speed according to actual conditions. In this way, the fuel requirements of the engine at the entire speed in this environment are fully met. The high-speed fuel boost pump requires a certain negative pressure value to be activated, so it is determined by the engine speed, and the engine speed is determined by the opening of the throat plate valve 3. At the same opening, the engine speed is determined by the air flow rate, and the negative pressure value generated by the air flow rate is also determined by the air density, and the air density is determined by the atmospheric pressure. They are closely related and complement each other, that is, whether the high-speed boost pump needs to be turned on is determined based on the combustion work of the engine. The more oxygen-rich the environment is, the earlier the high-speed boost pump will be activated. As the speed gradually approaches full speed, the high-speed boost pump reaches the pre-set maximum fuel injection amount under the gradually increasing negative pressure. If you need to adapt to a wider range of environmental factors and more precise fuel subsidies, you can set one or more fuel boost pumps again at the throat position. For example, please refer to Fig.18 There are two fuel auxiliary pumps, and the opening amounts of the first needle valves 801 of the multiple fuel auxiliary pumps are different. Different opening amounts are activated under different negative pressure values, producing a superposition effect, which will make the entire operating section of the engine more linear.

[0091] Generally speaking, traditional carburetors are affected by external factors, including altitude, temperature and humidity, which can affect each other.

[0092] Theoretically, in the same volume of atmosphere, if any two other factors remain unchanged: the higher the altitude, the lower the atmospheric density, the less oxygen content; the lower the altitude, the higher the atmospheric density, the more oxygen content; the higher the temperature, the lower the atmospheric density, the less oxygen content; the lower the temperature, the higher the atmospheric density, the more oxygen content. The humidity factor is quite special. Humidity is the value of how much water vapor can be dissolved in the atmosphere, and this solubility is related to the atmospheric temperature. The higher the atmospheric temperature, the higher the solubility, and the higher the humidity that can be achieved, which reduces the volume ratio of various gases in the atmosphere, and thus the less oxygen content in the atmosphere. On the contrary, the lower the humidity, the higher the oxygen content.

[0093] In reality, in the same region and the same season, the altitude factor plays a dominant role in most geographical environments. The higher the altitude, the lower the temperature and the lower the humidity; the lower the altitude, the higher the temperature and the higher the humidity. The humidity factor often has little effect on the combustion work of the engine. There are many conditions that affect humidity, and they change in the early, middle and late periods. Therefore, traditional carburetor manufacturers generally only consider the two factors of altitude and temperature, and provide adjustment periodic tables for the main and auxiliary metering orifice screws, oil needles, oil needle positions, and mixture ratio positions based on these two factors.

[0094] Table 1 Keihin PWK 36S AG carburetor

[0095]

[0096] Please refer to Table 1, which is the adjustment period table of the Keihin PWK 36S AG carburetor, where M / FT ASL is the altitude, TEMP is the air temperature, ASO is the number of counterclockwise turns of the mixture ratio screw, IJ is the auxiliary metering orifice screw model, NDL is the oil needle model, POS is the oil needle position, and MJ is the main metering orifice screw model. As can be seen from Table 1, the adjustment altitude range is 0 to 3000 meters. Changes in altitude and temperature have relatively insensitive and unchanging effects on the adjustment of the idle screw and the number of mixture ratio turns, while the adjustment of the fuel needle model, fuel needle position, and main orifice screw is relatively sensitive and variable. The adjustment of the secondary orifice screw and the number of mixture ratio turns has the greatest impact only on the situation from idle to 1 / 4 throttle valve opening. The fuel needle, fuel needle position, and main orifice screw have the greatest impact on the throttle valve opening from 1 / 2 to full open. The altitude range of 0 to 3000 meters basically includes all areas of my country except some areas of the Qinghai-Tibet Plateau. When collecting and summarizing the slope data on the fuel metering rod, the factors of atmosphere and temperature in high altitude areas are used as the background, and the engine is repeatedly tested from idle to full speed in the atmospheric environment simulated in the laboratory to collect data.

[0097] Laboratory simulation environment: atmospheric pressure: 67.24kpa (3000 meters above sea level), temperature: 20℃ (summer).

[0098] Taking the KTM 2016 250EXC engine as an example, after a large number of data collection experiments, a smooth fuel metering curve was obtained, and finally a fuel metering rod was finalized. This metering rod can meet the fuel supply of this engine from idling to full opening of the plate valve in this simulation environment.

[0099] In reality, the atmospheric pressure will rise by 10kpa for every 900m drop in altitude, which means that when the plate valve 3 is fully opened, in low altitude areas, under the negative pressure in the throat of the carburetor, the fuel injection amount of the injection hole has reached the maximum injection amount. In order to maintain the air-fuel ratio of 12.6-13.5, it is necessary to increase the fuel supply in other ways. Therefore, this can be achieved by adding a high-speed fuel subsidy pump. Therefore, if you want to get better environmental compatibility, you must simulate another atmospheric environment with a large span again, that is, standard atmospheric pressure and an altitude of 0M.

[0100] Laboratory simulation environment: The laboratory simulated atmospheric pressure is: 101.3kpa (0 meters above sea level), and the temperature is: -20℃ (winter).

[0101] According to all the specific environments in the environmental periodic table, with the same plate valve 3 fully open and the same air-fuel ratio maintained at 12.6-13.5, the fuel supply required at 0 meters altitude is the largest and the engine power output is the strongest. The data of the fuel boost pump was obtained through experiments.

[0102] From the physical characteristics of the atmosphere, at the same altitude, the atmosphere always flows from the high-pressure area to the low-pressure area. In the process of air flow, when passing through a narrow space, the air flow rate will increase. The faster the flow rate, the greater the negative pressure value generated in this narrow space, which is the Venturi effect. Therefore, in the channel of the carburetor, a contraction part will be designed at the throttle position or from the throttle to the engine port. This contraction part is called the Venturi tube, also called the throat, and its purpose is to speed up the air flow rate and generate more negative pressure values. Under the action of negative pressure, the fuel will be ejected from the gap between the fuel metering rod 1 and the oil delivery tunnel 2. The larger the opening of the plate valve 3, the faster the air flow rate, the greater the negative pressure value generated, and the more fuel is ejected. The ejected fuel is blown away by the high-speed airflow into fine oil droplets and mixed with the airflow to move forward. Since the engine generates heat when it is running, these small oil droplets will immediately evaporate into oil vapor and then be sent into the cylinder for combustion and work.

[0103] Through experiments, from low atmospheric pressure to high atmospheric pressure, the temperature is -20℃, the humidity problem can be ignored, the freezing point has exceeded the dew point, the air is relatively dry, and under standard atmospheric pressure and without the addition of high-speed subsidies, it was found that the carburetor was short of oil when the throttle valve was fully open. The combined effect of the fuel subsidy pump can just meet the amount of fuel required for these altitude spans and temperature spans, which is equivalent to forming an air and fuel sensor, which can intelligently mix a reasonable air-fuel ratio according to the negative pressure value in the carburetor throat at any time. In this way, the carburetor will no longer be sensitive to altitude and temperature.

[0104] The carburetor provided in the embodiment of the present invention can also be used for a four-stroke engine, including a second needle valve 9 and a second oil delivery pipe 10, the second needle valve 9 is movably arranged in the connecting hole of the first oil inlet end 4031 of the mixing chamber 403, and is used to adjust the opening size of the first oil inlet end, the first end of the second oil delivery pipe 10 is connected to the float chamber 401, and the second end of the second oil delivery pipe 10 is connected to the first oil inlet end 4031 of the mixing chamber 403. By adjusting the position of the first needle valve 801 in the connecting hole of the first oil inlet end 4031 along the axial direction, the opening size of the first oil inlet end 4031 entering the mixing chamber 403 can be adjusted.

[0105] A second needle valve 9 and a second oil delivery pipe 10 are added to the main structure of the carburetor, which can be used to adjust the mixture ratio adjustment system from idle to 1 / 4 opening. The second needle valve 9 is connected to the float chamber 401, and is also connected to the atmosphere (the tunnel of the air inlet), and is also connected to the throat part behind the plate valve 3. This second needle valve 9 mainly adjusts the size of the fuel passing through, thereby controlling the mixture ratio data at idle speed. The role of connecting to the atmosphere is that the airflow passing through the second needle valve 9 at idle speed will be faster, and a faster airflow velocity will generate a greater negative pressure, and a greater negative pressure will More fuel can be drawn from the valve port of the second needle valve 9, so the adjustment of the second needle valve 9 is that when it is turned clockwise, less fuel passes through, and the mixture ratio becomes thinner, and when it is turned counterclockwise, more fuel passes through, and the mixture ratio becomes thicker. After adjusting to the fastest speed, if the idle speed is found to be too high or too low, the idle speed can be adjusted. At this time, the "A" zone of the fuel metering rod 1 comes into play. As long as the upper and lower adjustment range does not exceed the "A" zone, the fuel metering rod 1 will not release fuel to disrupt the idle mixture ratio, until they are coordinated to adjust to a satisfactory idle speed.

[0106] See also Fig.11 The embodiment of the present invention also includes a choke 11, an oil float 12, an oil inlet needle valve 13, a fuel inlet hole 14, a float chamber air pressure balance hole 15, and an idle screw 16, wherein the choke 11 is used to control the on-off of the float chamber 401 and the mixing chamber 403, the oil float 12 and the oil inlet needle valve 13 are both arranged in the float chamber 401, and the idle screw 16 is arranged on the float chamber 401.

[0107] The embodiment of the present invention changes the traditional throttle valve into a plate valve. At the same time, the carburetor of this embodiment abandons the design of the secondary oil metering hole and the transition oil hole, the main oil metering hole screw and the choke, thereby simplifying the carburetor channel and enhancing the air permeability, thereby increasing the power output of the engine.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A carburetor, characterized in that: The fuel metering rod (1) comprises a first cylindrical body (101), wherein the first cylindrical body (101) is provided with an inclined surface; The carburetor further comprises an oil delivery tunnel (2), a plate valve (3) and a carburetor body (4), wherein the carburetor body (4) comprises a float chamber (401), and the fuel metering rod (1) further comprises a connecting body (102), wherein: The oil delivery tunnel (2) is provided with a circular through hole, and the diameter of the fuel metering rod is less than or equal to the diameter of the circular through hole, the connecting body (102) is fixedly arranged at the first end of the first cylinder (101), the first cylinder (101) of the fuel metering rod (1) is connected to the plate valve (3) through the connecting body (102), and the fuel metering rod (1) moves from the first end to the second end of the first cylinder (101) through the circular through hole to the float chamber (401); The plate valve (3) comprises a first plate valve body (301), a rotating boss structure (302), a first spring (303), and a slot structure (304); the rotating boss structure (302), the first spring (303), and the slot structure (304) are coaxially arranged in the cavity of the first plate valve body (301); the first end of the first spring (303) is fixedly connected to the cavity of the first plate valve body (301); the second end of the first spring (303) is fixedly connected to the rotating boss structure (302); the rotating boss structure (302) is fixedly arranged in the cavity of the first plate valve body (301); wherein: The rotating boss structure (302) comprises a first cavity structure (3021) and a plurality of bosses (3022); the slot structure (304) comprises a first base structure (3041) and a plurality of groove structures (3042); the number of the bosses (3022) is less than or equal to the number of the groove structures (3042); the first cavity structure (3021) passes through the first base structure (3041) so that the bosses (3022) are inserted into the groove structures (3042); and the fuel metering rod (1) is connected to the first cavity structure (3021) via the connector (102).

2. The carburetor according to claim 1, characterized in that The plate valve (3) comprises a second plate valve body (305), a metering rod anti-rotation column (306), a first baffle (307), a second spring (308), a metering rod positioning column (309), a first card (3010), a second baffle (3011), and a buckle (3012); the metering rod anti-rotation column (306), the first baffle (307), the second spring (308), the metering rod positioning column (309), the first card (3010), the second baffle (3011), and the buckle (3012) are coaxially arranged in sequence on the plate valve body (305). In the cavity of the second plate valve body (305), the metering rod anti-rotation column (306) is fixedly arranged in the cavity of the second plate valve body (305), the metering rod anti-rotation column (306) includes a second base structure (3061) and a second cylinder (3062), the metering rod positioning column (309) is connected to the inner cavity of the second plate valve body (305) by threading, the first end of the metering rod positioning column (309) is provided with a first blind hole (3091), and the second end of the metering rod positioning column (309) is provided with a second blind hole (3092), wherein, The fuel metering rod (1) is connected to the second base structure (3061) through the connecting body (102); the first baffle (307) and the second spring (308) are sequentially sleeved on the second cylinder (3062); the first end of the second cylinder (3062) is fixedly arranged on the second base structure (3061); the second end of the second cylinder (3062) is arranged in the first blind hole of the metering rod positioning column (309); the first card (3010) is clamped on the groove of the second cylinder (3062); the second baffle (3011) and the buckle (3012) are sequentially sleeved on the second end of the metering rod positioning column (309); and the buckle (3012) is also arranged on the groove of the second plate valve body (305).

3. The carburetor according to claim 1, characterized in that The inclined surface includes a straight line inclined surface or an arc inclined surface.

4. The carburetor according to claim 3, characterized in that The slope of the tangent line of the arc slope from the first end to the second end of the first cylinder (101) gradually increases.

5. The carburetor according to claim 2, characterized in that It also includes a second card (5), a third spring (6) and an adjusting rod (7); the adjusting rod (7) passes through the through hole of the second plate valve body (305) and is movably arranged in the second blind hole (3092) of the metering rod positioning column (309); the second card (5) and the third spring (6) are sequentially sleeved on the adjusting rod (7), and the second card (5) is clamped on the groove of the adjusting rod (7).

6. The carburetor according to claim 1, characterized in that The carburetor body (4) also includes a plurality of fuel auxiliary pumps. The carburetor body (4) also includes an air intake chamber (402), wherein the fuel auxiliary pump is connected to the air intake chamber (402) and the float chamber (401). The fuel auxiliary pump includes a first needle valve (801) and a first oil delivery pipe (802). The first needle valve (801) is movably arranged at the oil inlet end (4021) of the air intake chamber (402) and is used to adjust the opening size of the oil inlet end (4021) entering the air intake chamber (402). The first end of the first oil delivery pipe (802) is connected to the float chamber (401), and the second end of the first oil delivery pipe (802) is connected to the oil inlet end (4021) of the air intake chamber (402).

7. The carburetor according to claim 1, characterized in that The carburetor body (4) further comprises a second needle valve (9) and a second oil delivery pipe (10). The carburetor body (4) further comprises a mixing chamber (403). The second needle valve (9) is movably arranged in a connecting hole of a first oil inlet end (4031) of the mixing chamber (403) for adjusting the opening size of the first oil inlet end. The first end of the second oil delivery pipe (10) is connected to the float chamber (401), and the second end of the second oil delivery pipe (10) is connected to the first oil inlet end (4031).

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