CN209781064U - Carburetor provided with fuel auxiliary pump - Google Patents

Abstract

The utility model relates to a dispose carburetor of fuel auxiliary pump, including a plurality of fuel auxiliary pump (1), carburetor body (2) include float chamber (201) and air inlet chamber (202), wherein, fuel auxiliary pump (1) intercommunication float chamber (201) with air inlet chamber (202). The utility model discloses a fuel subsidy pump can provide the fuel secondary subsidy for the engine when the fuel that the carburetor provided can not satisfy the acting demand of engine to satisfy the engine required fuel demand in whole rotational speed in different environment.

Description

Carburetor provided with fuel auxiliary pump

Technical Field

The utility model relates to the technical field of engines, concretely relates to dispose carburetor of fuel auxiliary pump.

Background

The carburetor is an important component of vehicles such as motorcycles and the like, and mainly has the functions of mixing fuel oil and air in a certain proportion and atomizing. The carburetor can automatically prepare mixed gas with corresponding concentration according to the requirements of different working states of the engine, and outputs the mixed gas with corresponding amount for the combustion function of the engine.

the traditional carburetor is mainly divided into a plunger type carburetor and a vacuum film type carburetor, and the plunger type carburetor has the advantages of sensitive accelerator response, simple structure and stable work, and is also the most commonly used carburetor type in the field of motorcycle competition in China. The vacuum film type carburetor has the greatest advantage of being suitable for the operation of a quick-opening throttle valve, due to the two designs of the throttle valve and the throttle valve, the opening motion between the throttle valve and the throttle valve has certain delay, the opening speed of the throttle valve always lags behind the opening speed of the throttle valve, when the throttle valve is quickly opened, an effective negative pressure value is still kept behind the throttle valve, and the fuel oil is smoothly transited from an idle oil hole and a transition oil hole to a main metering oil hole in the delay opening process of the throttle valve, so that the phenomenon of oil shortage or flameout caused by the quick-opening throttle valve is avoided.

However, both the plunger type carburetor and the vacuum membrane type carburetor share a technical problem that the fuel cannot be replenished in time when the fuel shortage occurs in an extreme environment.

SUMMERY OF THE UTILITY MODEL

in order to solve the technical defects and deficiencies existing in the prior art, the utility model provides a carburetor provided with a fuel auxiliary pump.

Specifically, an embodiment of the utility model provides a dispose carburetor of fuel auxiliary pump, including a plurality of fuel auxiliary pumps, carburetor body, the carburetor body includes float chamber and air inlet chamber, wherein, fuel auxiliary pump intercommunication the float chamber with the air inlet chamber.

In an embodiment of the present invention, the fuel auxiliary pump includes a first opening adjusting structure and a first oil delivery pipe, wherein the first opening adjusting structure is movably disposed at the oil inlet of the air inlet chamber for adjusting the size of the opening of the oil inlet of the air inlet chamber, the first oil delivery pipe is connected to the float chamber at a first end, and the first oil delivery pipe is connected to the oil inlet of the air inlet chamber at a second end.

In an embodiment of the present invention, the first opening adjusting structure is a first needle valve.

in an embodiment of the present invention, the first needle valve includes a first threaded connector and a first needle body, a first end of the first threaded connector is fixedly connected to a first end of the first needle body, and the first needle valve is connected to an oil inlet end of the air inlet chamber through the first threaded connector.

In an embodiment of the present invention, the first needle valve further includes a first limiting spring, the first needle valve further includes a first cap, a first end of the first limiting spring is connected to the first cap, a second end of the first limiting spring is connected to a first port of an oil inlet of the air inlet chamber, and the first limiting spring is sleeved on the first threaded connector.

The utility model discloses an in one embodiment, still include the fuel sprayer, connect the second port department of the oil feed end of inlet chamber.

In an embodiment of the utility model, still include second opening adjustment structure and second defeated oil pipe, the carburetor body still includes the mixing chamber, second opening adjustment structure activity set up in the connecting hole of the first oil feed end of mixing chamber is used for adjusting the opening size of first oil feed end, the first end of second defeated oil pipe is connected to the float chamber, the second end of second defeated oil pipe is connected to the first oil feed end.

In an embodiment of the present invention, the second opening adjusting structure is a second needle valve.

In an embodiment of the present invention, the second needle valve includes a second threaded connection body and a second needle body, a first end of the second threaded connection body is fixedly connected to a first end of the second needle body, and the second needle valve passes through the second threaded connection body and the connection hole threaded connection of the first oil inlet end of the mixing chamber.

The utility model discloses an in one embodiment, still include second spacing spring, the second needle valve still includes the second cap, the first end of second spacing spring connect in the second cap, the second end of second spacing spring connect in the junction hole department of mixing chamber, just the second spacing spring cover is located on the second threaded connection body.

Compared with the prior art, the beneficial effects of the utility model are that:

The utility model discloses a fuel subsidy pump can provide the fuel secondary subsidy for the engine when the fuel that the carburetor provided can not satisfy the acting demand of engine to satisfy the engine required fuel demand in whole rotational speed in different environment.

Drawings

FIG. 1 is a schematic structural view of a carburetor according to an embodiment of the present invention;

FIG. 2 is a schematic view of another carburetor according to an embodiment of the present invention;

Fig. 3 is a schematic structural diagram of a first needle valve according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a second needle valve according to an embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a fuel metering rod according to an embodiment of the present invention;

Fig. 6 is a schematic structural diagram of another fuel metering rod provided in the embodiment of the present invention;

Fig. 7 is a schematic structural diagram of another fuel metering rod provided in an embodiment of the present invention;

Fig. 8 is a schematic structural diagram of another fuel metering rod according to an embodiment of the present invention;

Fig. 9 is a schematic structural view of an internal-adjusting plate valve provided in an embodiment of the present invention;

Fig. 10 is an exploded schematic view of an internal-adjusting plate valve according to an embodiment of the present invention;

fig. 11 is a schematic structural view of an external adjustment type plate valve provided in an embodiment of the present invention;

Fig. 12 is an exploded schematic view of an external adjustment type plate valve according to an embodiment of the present invention;

fig. 13 is a schematic structural view of a second clamping piece, a third spring and an adjusting rod according to an embodiment of the present invention;

FIG. 14 is a schematic view of a plunger carburetor according to an embodiment of the present invention;

Fig. 15 is a schematic structural view of a vacuum membrane carburetor according to an embodiment of the present invention.

Description of reference numerals:

1, a fuel auxiliary pump; 2 a carburetor body; 3 a first limit spring; 4 a second opening adjustment structure; 5 a second oil delivery pipe; 6 a second limit spring; 7, a fuel metering rod; 8, an oil transportation tunnel; 9, a plate valve; 10 a second card; 11 a third spring; 12 adjusting the rod; 13 a choke valve; 14 an oil float; 15, feeding an oil needle valve; 16 fuel inlet holes; 17 a float chamber air pressure balance hole; 18 idle speed screws; 101 a first opening adjustment structure; 102 a first oil delivery pipe; 201 a float chamber; 202 an air inlet chamber; 203 a mixing chamber; 401 a second threaded connection; 402 a second needle body; 403 a second cap; 701 a first cylinder; 702 a connector; 901 a first plate valve body; 902 rotating the boss structure; 903 a first spring; 904 a card slot configuration; 905 a second plate valve body; 906 a metering rod anti-rotation post; 907 a first baffle plate; 908 a second spring; 909 metering rod locator posts; 9010 a first card; 9011 a second blocking piece; 9012 buckling; 1011 a first threaded connector; 1012 a first needle body; 1013 a first cap; 2021 oil inlet end; 2031 a first oil inlet end; 9021 a first cavity structure; 9022 a boss; 9041 a first base structure; 9042 a groove structure; 9061 a second base structure; 9062 second cylinder; 9091 a first blind hole; 9092 a second blind hole; 90612 prevent rotation.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the present invention is not limited thereto.

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 coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present. Like reference numerals refer to like elements throughout.

spatially relative terms, such as "below …," "below …," "below," "above …," "above," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated 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 depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below …" can include both an orientation of "above …" and "below …". The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Example one

Referring to fig. 1, fig. 1 is a schematic structural diagram of a carburetor according to an embodiment of the present invention. The embodiment provides a carburetor provided with a fuel auxiliary pump, which comprises a plurality of fuel auxiliary pumps 1 and a carburetor body 2, wherein the carburetor body 2 comprises a float chamber 201 and an air inlet chamber 202, and the fuel auxiliary pump 1 is communicated with the float chamber 201 and the air inlet chamber 202.

Wherein, the fuel that the fuel pump was carried is used for storing to float chamber 201 to guarantee the supply of fuel, and intake chamber 202 is used for supplying the air, and this embodiment passes through fuel auxiliary pump 1 and communicates float chamber 201 and intake chamber 202 to when the engine appears the starved oil phenomenon, can transmit the fuel that stores in the float chamber 201 to intake chamber 202 through fuel auxiliary pump 1, thereby compensate the starved oil phenomenon.

Preferably, the float chamber 201 may be made of a transparent or translucent material, and the inside of the float chamber can be visually observed.

The utility model discloses a fuel subsidy pump can provide the fuel secondary subsidy for the engine when the fuel that the carburetor provided can not satisfy the acting demand of engine to satisfy the engine required fuel demand in whole rotational speed in different environment.

It is also possible to provide one or more fuel auxiliary pumps, for example two, see fig. 2, if it is desired to accommodate a broader range of environmental factors and a more precise fuel auxiliary.

Specifically, the fuel assist pump 1 includes a first opening adjusting structure 101 and a first oil delivery pipe 102, wherein the first opening adjusting structure 101 is movably disposed at an oil inlet end 2021 of the air inlet chamber 202 and is used for adjusting the size of an opening of the oil inlet end 2021 entering the air inlet chamber 202, a first end of the first oil delivery pipe 102 is connected to the float chamber 201, and a second end of the first oil delivery pipe 102 is connected to the oil inlet end 2021 of the air inlet chamber 202.

The oil inlet end 2021 includes a first port, a second port and a third port, wherein the first port and the second port are coaxially disposed, a through hole is formed from the first port to the second port, and the third port communicates with the through hole formed from the first port to the second port, the first opening adjusting structure 101 enters the through hole through the first port, and the second end of the first oil delivery pipe 102 is connected to the third port of the oil inlet end 2021, so that fuel in the float chamber 201 can be delivered to the air inlet chamber 202 through the first oil delivery pipe 102, and the opening size of the third port can be adjusted by adjusting the axial position of the first opening adjusting structure 101, so as to adjust the amount of fuel entering the air inlet chamber 202. The first opening adjustment structure 101 changes the opening area that flows into the intake chamber 202 through the third port, thereby enabling the purpose of intercepting or adjusting the flow rate.

Preferably, the first opening regulating structure 101 is a first needle valve whose valve plug is in a needle shape and mainly serves to regulate the flow of fuel, and the first needle valve is a trim valve whose valve port opening is gradually enlarged and is finely regulated continuously from the closing of the third port to the opening of the third port, thereby enabling to precisely regulate the amount of fuel flowing from the third port into the intake chamber 202.

Further, please refer to fig. 3, the first needle valve includes a first threaded connector 1011 and a first needle 1012, the first end of the first threaded connector 1011 is fixedly connected to the first end of the first needle 1012, and the first needle valve is threadedly connected to the oil inlet 2021 of the air inlet chamber 202 through the first threaded connector 1011, wherein the first threaded connector 1011 has an external thread, an internal thread is disposed at the first port of the oil inlet 2021, so as to realize the threaded connection between the first needle valve and the first port of the oil inlet 2021, and thus the axial movement of the first needle valve can be realized.

Further, the carburetor may further include a first limiting spring 3, the first needle valve further includes a first cap 1013, the first cap 1013 is fixedly connected to the second end of the first threaded connector 1011, the first end of the first limiting spring 3 is connected to the first cap 1013, the second end of the first limiting spring 3 is connected to the first port of the oil inlet end 2021 of the air inlet chamber 202, and the first threaded connector 1011 is sleeved with the first limiting spring 3, the first needle valve may be limited by the first limiting spring 3 to move along the axial direction, wherein the outer surface of the first threaded connector 1011 may be a full external thread or a part of an external thread.

Further, the carburetor may also include an oil jet that is connected to the second port of the oil intake end 2021 of the intake chamber 202. The fuel injection nozzle can achieve the effect that the fuel flowing into the oil inlet end 2021 is changed into the injection shape into the intake chamber 202, thereby achieving the uniform dispersion of the fuel in the intake chamber 202.

The fuel oil auxiliary pump provided by the embodiment is mainly used for the oil shortage phenomenon when an engine runs at high speed or full speed, when the oil shortage phenomenon occurs in a carburetor, for example, under extreme conditions, the fuel oil provided by the carburetor can not meet the work requirement of the engine, the engine needs secondary auxiliary of the fuel oil, namely, the high-speed fuel oil auxiliary function, namely, an oil nozzle is arranged at the inner side of a Venturi tube (choke tube), the oil nozzle is controlled by a first needle valve, then the first needle valve is connected with an air inlet chamber 202, the first needle valve is arranged with a fuel oil auxiliary opening amount which can just meet the requirement of the engine at full speed according to the actual situation, so that the fuel oil requirement of the engine in the whole rotating speed in the environment is completely met, and the high-speed fuel oil auxiliary pump can only be activated by a certain negative pressure value, therefore, the engine speed is determined by the engine speed, the engine speed is determined by the opening of the throat valve 9, the engine speed is determined by the air flow rate under the same opening, the negative pressure value generated by the air flow rate is also determined by the air density, the air density is determined by the atmospheric pressure, the relationship between the negative pressure value and the air density is close to each other, namely, whether the high-speed auxiliary pump needs to be started or not is determined according to the combustion work of the engine, the high-speed auxiliary pump is activated earlier in the environment with more sufficient oxygen, and the high-speed auxiliary pump reaches the preset maximum fuel injection amount under the gradually enhanced negative pressure as the engine speed gradually approaches the full speed. If the wider environmental factors and more accurate fuel assistance need to be adapted, one or more fuel assistance pumps can be arranged at the position of the throat again, the opening amount of each first needle valve is different by adjusting the taper of the first needle valve of each fuel assistance pump, and the different opening amounts are activated under different negative pressure values to generate a superposition effect, so that the whole operation section of the engine becomes more linear.

Through experiments, from low atmospheric pressure to high atmospheric pressure, the air temperature is-20 ℃, the humidity problem can be ignored, the freezing point exceeds the dew point, the air is relatively dry, under the standard atmospheric pressure and under the condition of not adding high-speed assistance, the phenomenon that the engine of the carburetor is lack of oil under the condition that the throttle valve is fully opened is found, the fuel oil quantity required by the altitude span and the air temperature span can be just met by utilizing the combined action of the fuel oil assistance pump, the method is equivalent to forming an air and fuel oil sensing system, and the reasonable air-fuel ratio can be mixed at any time according to the negative pressure value, so that the carburetor can not become sensitive to the altitude and the air temperature any more.

Please refer to fig. 1 again, the embodiment of the present invention provides a carburetor further comprising a second opening adjusting structure 4 and a second oil delivering pipe 5, the carburetor body 2 further comprises a mixing chamber 203, the second opening adjusting structure 4 is movably disposed in the connecting hole of the first oil inlet 2031 of the mixing chamber 203, for adjusting the opening size of the first oil inlet 2031, the first end of the second oil delivering pipe 5 is connected to the float chamber 201, the second end of the second oil delivering pipe 5 is connected to the first oil inlet 2031, the air outlet end of the mixing chamber 203 is connected to the cylinder of the engine, and the mixing chamber 203 introduces the mist particle fuel and the air mixture into the cylinder of the engine.

first oil feed end 2031 includes the connecting hole, first port, the second port, wherein first port and the coaxial setting of second port, be a through-hole from first port to second port, second opening regulation structure 4 activity sets up in the connecting hole, can adjust structure 4 along axial position through adjusting the second opening, adjust the opening size of this through-hole, thereby adjust the fuel volume that oil float chamber 201 got into mixing chamber 203, the second end of second defeated oil pipe 5 is connected to the second port of first oil feed end 2031, thereby can be with the fuel in the float chamber 201 transmit to mixing chamber 203 in through second defeated oil pipe 5. The second opening adjustment structure 4 changes the opening area to the mixing chamber 203 through the second port, thereby enabling the purpose of intercepting or adjusting the flow rate.

Preferably, the second opening adjustment structure 4 is a second needle valve.

Further, please refer to fig. 4, the second needle valve includes a second thread connection body 401 and a second needle body 402, a first end of the second thread connection body 401 is fixedly connected to a first end of the second needle body 402, the second needle valve is in threaded connection with a connection hole of the first oil inlet end 2031 of the mixing chamber 203 through the second thread connection body 401, wherein the second thread connection body 401 has an external thread, and an internal thread is arranged in the connection hole, so that the threaded connection between the second needle valve and the connection hole can be realized, and the second needle valve can move along the axial direction.

further, the carburetor may further include a second limiting spring 6, the second needle valve further includes a second cap 403, the second cap 403 is fixedly connected to a second end of the second threaded connector 401, a first end of the second limiting spring 6 is connected to the second cap 403, a second end of the second limiting spring 6 is connected to a connecting hole of the mixing chamber 203, the second limiting spring 6 is sleeved on the second threaded connector 401, and the second needle valve may be limited by the second limiting spring 6 to move along the axial direction, wherein an outer surface of the second threaded connector 401 may be completely provided with an external thread or partially provided with an external thread.

The main structure of the carburetor is additionally provided with a second opening adjusting structure 4 and a second oil delivery pipe 5, which can be used for adjusting and calibrating a mixing ratio adjusting system from idle speed to 1/4 of opening, the second opening adjusting structure 4 is connected with a float chamber 201, is simultaneously connected with atmosphere (a tunnel of an air inlet) and is simultaneously connected with a throat part behind a throttle valve, the second opening adjusting structure 4 mainly adjusts the passing size of fuel oil so as to control mixing ratio data in idle speed, the effect of connecting with the atmosphere is that the air flow passing through the vicinity of the second opening adjusting structure 4 is faster in idle speed, the faster air flow speed generates larger negative pressure, the larger negative pressure can absorb more fuel oil from the valve port position of the second opening adjusting structure 4, so that the adjustment of the second opening adjusting structure 4 is that the fuel oil passing when being screwed clockwise is reduced, the mixing ratio is diluted, and the fuel oil passing when being screwed anticlockwise is increased, the mixing ratio is made rich.

example two

Referring to fig. 1 again, the present embodiment provides a carburetor, wherein the carburetor is configured with all the devices described in the first embodiment, that is, all the devices described in the first embodiment can be used on the carburetor, the principle of the carburetor is the same as that described in the first embodiment, and will not be described herein again, and the carburetor is further configured with a fuel metering rod 7, the fuel metering rod 7 includes a first cylinder 701, wherein the first cylinder 701 is provided with an inclined surface.

All carburettors work under the atmospheric pressure environment, the atmospheric pressure is a powerful force for exerting pressure on everything, the carburettors also utilize various physical characteristics of the atmosphere to enable fuel oil and the atmosphere to be mixed and transmitted to the cylinder for combustion and work, the work of the engine cylinder is realized by fully combusting oxygen and fuel oil in the atmosphere, so that heat energy is converted into kinetic energy, in the process, air and fuel oil are mixed according to a certain proportion to enable the fuel oil to be combusted and work, the proportion is the mixing ratio of the air and the fuel oil, also called the air-fuel ratio, the air-fuel ratio is not always constant in the actual work of the engine, and the air-fuel ratio can be adjusted according to different engine rotating speeds, so that effective power output is achieved.

Theoretically, 14.7kg of air is required to completely burn 1kg of gasoline. Since the air-fuel ratio is represented by letter a, the air-fuel ratio a is equal to the weight of air divided by the weight of fuel, and the air-fuel ratio for theoretical sufficient combustion is: 14.7:1 to 14.7, the theoretical minimum air-fuel mixture ratio is: 7:1 to 7, the theoretical maximum air-fuel mixture ratio is: since 20:1 is 20, the present embodiment refers to 14.7 as a reference node, and numbers below 14.7 refer to a richer air-fuel ratio, and conversely refer to a leaner air-fuel ratio.

in practical application, according to the work requirement of the engine, the following air-fuel ratios can be summarized:

1. When the engine is started, the carburetor should provide a richer mixture with a being 6.9, and sometimes an extra-dense mixture with a being 3. 2. When the engine runs at idle speed, the carburetor should provide a richer mixed gas with a being 10-12.4. 3. When the engine runs at a medium speed, the carburetor should provide a standard mixture with a being 13-15. 4. When the engine runs at full speed, the carburetor should provide a richer air mixture of 12.6-13.5.

Therefore, different parts on the carburetor need to be adjusted to approach the air-fuel ratio data in different rotating speed periods, an oil supply system of the traditional carburetor generally comprises parts such as a choke valve, a mixing ratio screw, an idle screw, an auxiliary metering oil hole, a transition oil hole, a main metering oil hole, an oil needle, a throttle valve and the like, the parts are coordinated with each other, and the working principles are as follows:

1, when starting, especially under the condition that air temperature is low, need to pull up "choke valve", the "choke valve" design has two kinds, one kind is isolated more air, one kind is release more fuel, no matter what final purpose is to make the air-fuel ratio figure reduce, the lower required data of air temperature is just littleer, the mixture becomes rich promptly, then "choke valve" cooperates vice volume oilhole and throttle valve clearance and works together to produce the air-fuel ratio data between 3 ~ 6.9 that the engine needs when cold start.

2, when the engine is idling, the engine is preheated, fuel has good evaporability during the transmission process, a choke valve is closed, and at the time, the auxiliary metering hole, the throttle valve gap and the mixing ratio screw work together, so that the air-fuel ratio data of 10-12.4 required by the engine when the engine is idling is generated.

3, at the middle speed, the auxiliary oil metering hole only has a small amount of oil supply, the influence of a mixing ratio screw is small, the main oil metering hole, an oil needle and a throttle valve are mainly matched, and a transition oil hole is formed in the vacuum membrane carburetor and mainly provides fuel oil required by the engine from idling to the middle speed, so that better transition is achieved, and finally air-fuel ratio data between 13 and 15 required by the engine at the middle speed are generated.

And 4, at full speed, the auxiliary metering oil hole and the transition oil hole almost stop supplying oil, the mixing ratio screw has no meaning, the oil needle and the throttle valve also have no meaning, and the main metering oil hole only work through the screw, so that the air-fuel ratio data between 12.6 and 13.5 required by the engine at full speed is generated.

In an embodiment of the present invention, the inclined plane of the first cylinder 701 may be a straight inclined plane or a curved inclined plane.

Referring to fig. 6, the slope of fig. 6 is a straight slope, that is, a straight slope is arranged from the first end to the second end of the first cylinder 701, wherein the first end of the first cylinder 701 is the end far away from the float chamber 201 of the carburetor, and the second end of the first cylinder 701 is the end close to the float chamber 201, the slope of the straight slope is larger (i.e., the angle of the straight slope with the X axis is smaller), at high engine speed and full engine speed, the fuel metering rod 7 will provide more fuel, thereby reducing the data of the air-fuel ratio, which is equivalent to the screw of the main fuel metering hole in the conventional carburetor. Conversely, if the slope of the straight ramp is less (i.e., the straight ramp is angled more toward the X-axis), the meter bar will provide relatively less fuel at high and full engine speeds, thereby increasing the air-fuel ratio data. Referring to fig. 7, fig. 7 shows the slope of the metering rod with different slopes, wherein the slopes a, B, C and D have gradually increasing slopes, and wherein the straight slope from the first end to the second end of the first cylinder 701 may include a start-up and idle region, a low-speed to medium-high-speed operating region and a high-speed to full-speed operating region, so that the engine may be operated at different operating conditions by adjusting the height of the fuel metering rod from the oil transportation tunnel, thereby adjusting the clearance between the fuel metering rod and the outlet end of the oil transportation tunnel. And the greater the slope of the straight slope, the greater the variation in the injected fuel quantity when transitioning from the start-up and idle regions to the high-speed to full-speed operating region.

it should be noted that, according to the requirements of different engine operating states, the length and diameter of the fuel metering rod, the inclination of the linear slope, and the setting from the start to the full-speed operating area are all different, and are not specifically limited herein, and those skilled in the art can easily perform machining and manufacturing according to the actual situation according to the embodiment.

Referring to fig. 5, the inclined plane in fig. 5 is an arc inclined plane, that is, an inclined plane having a radian is arranged from the first end to the second end of the first cylinder 701, and the slope of a tangent line from the first end to the second end of the first cylinder 701 is gradually increased, the whole arc inclined plane is formed by a curved surface from the first end to the second end, and the slope of the curved surface from the first end to the second end of the arc inclined plane is infinitely close to 90 degrees, so that fuel supply of the engine in different rotation speed periods is satisfied. Referring to fig. 7, fig. 7 shows the slope of the metering rod with different curvatures, wherein the curvatures of the slope C-1, the slope C-2, the slope C-3 and the slope C-4 are gradually increased, and wherein the slope of the arc may include a start-up and idle region, a low-speed to medium-speed operating region and a high-speed to full-speed operating region from the first end to the second end of the first cylinder 701, so that the clearance between the metering rod and the outlet end of the oil transportation tunnel may be adjusted by adjusting the height of the metering rod from the oil transportation tunnel, thereby achieving the required state from start-up to full-speed operation. The larger the radian of the arc slope is, the more fuel can be provided by the fuel metering rod when the engine is in a low rotating speed region to a medium rotating speed region, so that the data of the air-fuel ratio is reduced, and the function of the fuel metering rod is equal to that of an auxiliary metering oil hole screw and a transition oil hole in a traditional carburetor. Conversely, if the camber is smaller the metering rod will provide relatively less fuel from the low to the medium speed regions of the engine, thereby increasing the air-fuel ratio data.

It should be noted that, according to the requirements of different engine operating states, the length and diameter of the fuel metering rod, the slope rate of the arc slope, and the setting from the start to the full-speed operating region are all different, and are not specifically limited herein, and those skilled in the art can easily perform the processing and manufacturing according to the actual situation according to the embodiment.

Referring to fig. 8, the fuel metering rod 7 of the present embodiment further includes a buffer area, i.e., area a in fig. 8, which is a cylinder without inclined surface, and this area is an idle adjustment area, and the fuel metering rod 7 with the buffer area is suitable for a carburetor of a four-stroke engine, because the four-stroke engine needs more accurate fuel supply, especially between the idle and 1/4 opening of the plate valve, and thus the buffer area is provided on the fuel metering rod 7.

The fuel oil gushing is more when the negative pressure in the carburetor throat is larger, even under the same plate valve opening amount, the fuel oil gushing is less when the atmospheric pressure is lower, the fuel oil gushing is more when the atmospheric pressure is higher, the fuel oil supply is automatically adjusted by combining the atmospheric pressure and the air temperature at the moment through the engine, the atmospheric pressure is 67.24-101.3 kpa, the altitude is equal to the span between 3000 and 0 meters, the temperature is from 20 ℃ to-20 ℃, and the oxygen content in the atmosphere is thickened along with the reduction of the air temperature.

The fuel metering rod of the embodiment has the advantages that since the same fuel conveying pipeline is used from idling to full speed, namely a pipeline matched between the fuel metering rod and the oil transportation tunnel, under the opening of any plate valve, because the metering rod is designed into a smooth inclined plane, therefore, the oil inlet gap of the pipeline is always larger than the oil outlet gap, and when fluid flows from one space to another narrow space, the flow rate will be increased, i.e. the fuel injection will be better, the atomization will be more complete, and secondly, at idle, the line will already be filled with fuel, therefore, when the plate valve is suddenly opened in an idling state, namely the accelerator is suddenly opened, the phenomenon of instantaneous oil shortage of the engine can not occur, and the fuel metering rod replaces the designs of the auxiliary oil hole, the transition oil hole, the main oil hole and the like, so that the oil delivery channel is designed more simply, and satisfactory effects can be achieved no matter in fierce acceleration or response of an accelerator. Moreover, as the atomization effect is improved, the air mobility is improved, and the power of the engine for doing work is improved, the aims of saving oil and protecting environment are fulfilled.

Referring to fig. 1, the carburetor further includes an oil transfer tunnel 8, a plate valve 9, and a fuel metering rod 7 further includes a connecting body 702, wherein,

The oil transportation tunnel 8 is provided with a circular through hole, the diameter of the first cylinder 701 of the fuel metering rod is smaller than or equal to that of the circular through hole of the oil transportation tunnel 8, the connecting body 702 is fixedly arranged at the first end of the first cylinder 701, the first cylinder 701 of the fuel metering rod 7 is connected with the plate valve 9 through the connecting body 702, and the fuel metering rod 7 movably penetrates through the circular through hole to the float chamber 201 from the first end to the second end of the first cylinder 701. The oil transfer tunnel 8 communicates the float chamber 201 with the mixing chamber 203.

preferably, the diameter of the first cylinder 701 of the fuel metering rod is 95% -100% of the diameter of the circular through hole of the oil transportation tunnel 8.

the first cylinder 701 is matched with the oil delivery tunnel 8, the first cylinder 701 of the fuel metering rod 7 can move up and down along the axial direction in the oil delivery tunnel 8, so that a gap is generated according to the matching of the inclined surface of the first cylinder 701 and the oil delivery tunnel 8, when the first cylinder 701 moves upwards along the axial direction, the gap generated by the matching of the inclined surface of the first cylinder 701 and the oil delivery tunnel 8 is larger and larger, fuel can be supplied to an engine more and more, and the engine can be started to an idling area, an idling area to a low-speed area and a full-speed working area by adjusting the gap generated by the matching of the first cylinder 701 and the oil delivery tunnel 8.

Preferably, the connection 702 is a threaded connection, so that the first cylinder 701 is screwed to the plate valve 9 by means of the connection 702.

Because the change of the high-low position of the fuel metering rod 7 can sensitively affect the mixing ratio from idle speed to 1/4 of the opening, the traditional clamping groove design cannot be applied, a finer adjustment mode is needed, the embodiment realizes the adjustment of the high-low position of the fuel metering rod 7 by utilizing threads, and the inclined surface of the fuel metering rod always faces to the side of an engine during working according to aerodynamics and better atomization effect, so that the condition that the inclined surface needs to be returned after each time of high-low adjustment is involved.

The plate valve 9 is mainly used for adjusting the position of the fuel metering rod 7 in the axial direction, the plate valve 9 comprises two forms, one is an inner adjusting plate valve, the other is an outer adjusting plate valve, and the purpose of adjusting the position of the fuel metering rod 7 in the axial direction can be achieved by using the inner adjusting plate valve or the outer adjusting plate valve.

Referring to fig. 9 and 10, the internal adjustment type plate valve includes a first plate valve body 901, a rotary boss structure 902, a first spring 903, and a slot structure 904, the rotary boss structure 902, the first spring 903, and the slot structure 904 are coaxially disposed in the cavity of the first plate valve body 901, a first end of the first spring 903 is fixedly connected to an inner wall in the cavity of the first plate valve body 901, a second end of the first spring 903 is fixedly connected to a top wall of the rotary boss structure 902, so that the first spring 903 can move between the inner wall in the cavity of the first plate valve body 901 and the top wall of the rotary boss structure 902, the rotary boss structure 902 is fixedly disposed in the cavity of the first plate valve body 901, wherein the rotary boss structure 902 includes a first cavity structure 9021 and a plurality of bosses 9022, the plurality of bosses 9022 are disposed on the first cavity structure 9021, the first cavity structure 9021 has a through hole structure, the clamping groove structure 904 comprises a first base structure 9041 and a plurality of groove structures 9042, the groove structures 9042 are arranged on the side wall of the first base structure 9041, the number of the bosses 9022 is smaller than or equal to that of the groove structures 9042, the first cavity structures 9021 penetrate through the first base structure 9041 to enable the bosses 9022 to be clamped into the groove structures 9042, and the first plate valve body 901 is fixed, so that the bosses 9022 can be clamped into the groove structures 9042 under the action force of the first spring 903, and meanwhile, the fuel metering rod 7 is connected with the first cavity structures 9021 through the connecting body 702.

preferably, an inner wall of the first cavity 9021 is provided with an internal thread, so that the fuel metering rod 7 is in threaded connection with the first cavity 9021 through the connecting body 702.

Preferably, the material of the rotating boss structure 902 is nylon.

The fuel metering rod 7 of the embodiment is matched with the first cavity structure 9021, a first spring 903 is fixed at the top of the first cavity structure 9021, meanwhile, the first cavity structure 9021 is provided with a plurality of bosses 9022, for example, the number of the bosses 9022 is 4, each boss 9022 can be correspondingly clamped into a groove structure 9042, under the action force of the first spring 903, the bosses 9022 are always in the groove structures 9042, the inclined surface of the fuel metering rod 7 faces the side of an engine at the moment, when the height position of the fuel metering rod 7 needs to be adjusted, the fuel metering rod 7 can be adjusted in a counterclockwise or clockwise screwing mode, because the number of the bosses 9022 is 4, the groove structures 9042 are in the form of a cross clamping groove, namely, 4 groove structures 9042 are uniformly arranged on a 360-degree circle stroke, and assuming that the included angle of each groove structure 9042 is 90 degrees, each 1/4 circle can be an adjustment unit, namely 90 is a unit, no matter anticlockwise or clockwise, after the adjustment is finished, the fuel metering rod 7 is pushed inwards, the boss 9022 is separated from the groove structure 9042, the fuel metering rod 7 is rotated at the moment, so that the inclined surface of the fuel metering rod 7 is rotated to one side of an engine and then is reset, the inclined surface of the fuel metering rod 7 returns to the original position, the height position of the fuel metering rod 7 is changed, the adjustment is finished, according to actual measurement, according to the thread design of British system 40G, when the adjustment is carried out for 1/4 circle, the height change amplitude of the fuel metering rod 7 is 0.1524 mm, and the rotation for a whole circle is 0.6096 mm.

The embodiment of the utility model provides a do not do specifically to boss 9022 and groove structure 9042's quantity and prescribe a limit to as long as can guarantee that fuel metering stick 7 is after through position adjustment, and its inclined plane still towards engine one side, alright in order to realize the purpose of this embodiment.

Referring to fig. 11 and 12, the external adjustment type plate valve includes a second plate valve body 905, a metering rod rotation-preventing column 906, a first blocking piece 907, a second spring 908, a metering rod positioning column 909, a first clamping piece 9010, a second blocking piece 9011, a buckle 9012, the metering rod rotation-preventing column 906, the first blocking piece 907, the second spring 908, a metering rod positioning column 909, the first clamping piece 9010, the second blocking piece 9011, and the buckle 9012 are coaxially disposed in a cavity of the second plate valve body 905 in sequence, the metering rod rotation-preventing column 906 is fixedly disposed in the cavity of the second plate valve body 905, the metering rod rotation-preventing column 906 includes a second base structure 9061 and a second cylinder 9062, an anti-rotation ridge 90612 may be disposed on an outer side wall of the second base structure 9061, and a groove is correspondingly disposed in the cavity of the second plate valve body 905, so that the anti-rotation ridge 90612 is clamped into the groove in the cavity of the second plate valve body 905 to achieve that the metering rod rotation-preventing column 906 is fixedly disposed in the cavity of the second plate valve, the metering rod positioning column 909 is connected to the inner cavity of the second plate valve body 905 through a thread, that is, an external thread is arranged on the outer side wall of the metering rod positioning column 909, an internal thread is arranged at the corresponding position of the inner cavity of the second plate valve body 905, so that the metering rod positioning column 909 is in threaded connection with the inner cavity of the second plate valve body 905, a first blind hole 9091 is arranged at the first end of the metering rod positioning column 909, a second blind hole 9092 is arranged at the second end of the metering rod positioning column 909, wherein,

The fuel metering rod 7 is connected with the second base structure 9061 through the connecting body 702, the first blocking piece 907 and the second spring 908 are sequentially sleeved on the second cylinder 9062, the first blocking piece 907 is used for blocking the second spring 908 and blocking the second spring 908 from falling onto the second base structure 9061, the first end of the second cylinder 9062 is fixedly arranged on the second base structure 9061, the first blocking piece 907 and the second spring 908 are both required to be arranged on the lower side of the groove of the second cylinder 9062, the second end of the second cylinder 9062 is arranged in the first blind hole of the metering rod positioning column 909, namely, the upper end part of the groove of the second cylinder 9062 is clamped in the first blind hole, the first clamping piece 9010 is clamped on the groove of the second cylinder 9062, so that the metering rod rotation prevention column 906 and the metering rod positioning column 909 are connected, the second spring 908 is limited between the first blocking piece 907 and the first blocking piece 9010, the second piece 9011 and the clamping positioning column 9012 are sequentially sleeved on the second end of the metering rod 909, the buckle 9012 is further disposed in another groove of the second plate valve body 905, the buckle 9012 is used for limiting the positioning column 909 of the metering rod, and the buckle 9012 is elastic and is in an open-loop arrangement, so that the buckle 9012 can be conveniently installed and taken out when external force is applied to the buckle 9012.

Preferably, the fuel metering rod 7 is screwed with the second base structure 9061 through the connecting body 702, that is, an internal thread is provided in a blind hole of the second base structure 9061, so that the connecting body 702 is screwed with the second base structure 9061.

Referring to fig. 13, when the position of the fuel metering rod 7 is adjusted by using the external adjustment type plate valve, a second card 10, a third spring 11 and an adjusting rod 12 are further installed, the adjusting rod 12 passes through a through hole of the second plate valve body 905 and is movably disposed in a second blind hole 9092 of the metering rod positioning column 909, the second card 10 and the third spring 11 are sequentially sleeved on the adjusting rod 12, and the second card 10 is clamped on a groove of the adjusting rod 12.

The adjusting rod 12 is used for screwing the measuring rod positioning column 909, so that the height position of the fuel oil measuring rod 7 is adjusted. The carburetor body further comprises a cover body, the cover body is internally provided with a plate valve, the adjusting rod 12 needs to penetrate through a through hole in the cover body so as to be inserted into the second blind hole 9092, the third spring 11 is used for limiting the movement of the adjusting rod 12 between the cover body, and the second clamping piece 10 is located at the position for limiting the adjusting rod 12, so that when external force is applied to the adjusting rod 12, the adjusting rod 12 can move axially.

Preferably, the part of the adjusting rod 12 inserted into the second blind hole 9092 is a hexagonal adjusting rod, and the second blind hole 9092 is a hexagonal blind hole, so that when the adjusting rod 12 is inserted into the second blind hole 9092, when the adjusting rod rotates clockwise or counterclockwise, the rotation of the positioning column 909 of the metering rod can be realized, and the height position of the fuel metering rod 7 can be adjusted.

preferably, the adjustment lever 12 is marked with a scale for recording the number of revolutions.

When utilizing outer debugging plate valve to transfer the school, need open the air throttle to the biggest to make plate valve 9 rise to the peak, then press down the mediation handle that the carburetor was covered perpendicularly, make in adjusting pole 12 embedding corresponding second blind hole 9092, then carry out anticlockwise or clockwise timing, after the school finishes loosen the throttle and change the handle can, because the nylon cylinder's of fixed metering stick both sides all have the stupefied 90612 design of anti-rotation, consequently the inclined plane direction of fuel metering stick 7 can not change when carrying out above-mentioned operation, all the time towards that side of engine, also mark the scale on adjusting pole 12 simultaneously, conveniently take notes the number of turns or return to zero. The outer adjusting plate valve can be directly adjusted outside without detaching the plate valve, and the outer adjusting plate valve is convenient to use.

Please refer to fig. 1, the embodiment of the present invention further includes a choke valve 13, an oil float 14, an oil inlet needle valve 15, a fuel inlet hole 16, a float chamber air pressure balance hole 17, and an idle screw 18, wherein the choke valve 13 is disposed at the second oil inlet end of the mixing chamber 203 for controlling the on-off of the float chamber 201 and the mixing chamber 203, thereby controlling the amount of fuel entering the mixing chamber from the float chamber 201, the oil float 14 and the oil inlet needle valve 15 are both disposed in the float chamber 201, and the idle screw 18 is disposed on the float chamber 201.

The embodiment of the utility model provides a change traditional throttle valve into the plate valve, the carburetor of this embodiment has given up the design of vice gauge oilhole and transition oilhole, main gauge oilhole screw and choke valve simultaneously to make the carburetor passageway succinct, the air trafficability characteristic reinforcing, thereby increased the power output of engine.

In general, conventional carburetors are subject to external factors including: altitude factors, air temperature factors and humidity factors, which may influence each other.

Theoretically, in the same volume of atmosphere, under the condition that any other 2 factors are unchanged: the higher the altitude, the lower the atmospheric density, the less the oxygen content, and the lower the altitude, the higher the atmospheric density, the more the oxygen content; the higher the air temperature, the lower the atmospheric density, the less the oxygen content, and the lower the air temperature, the higher the atmospheric density, the more the oxygen content. The humidity factor is special, the humidity is a numerical value of the amount of water vapor which can be dissolved in the atmosphere, the dissolving amount is related to the atmospheric temperature, the higher the atmospheric temperature is, the higher the dissolving capacity is, and the higher the achievable humidity is, so that the volume ratio of each gas in the atmosphere is reduced, the oxygen content in the atmosphere is lower, and conversely, the lower the humidity is, the higher the oxygen content is.

In reality, in the same region and the same season, the altitude factor in most geographic environments plays a leading role, and the higher the altitude is, the lower the air temperature is, and the lower the humidity is; the lower the altitude, the higher the air temperature and the higher the humidity. The humidity factor usually has little influence on the combustion work of the engine, and the conditions influencing the humidity are many and change in the morning, the evening and the night. Therefore, the conventional carburetor manufacturer only considers two factors of altitude and air temperature, and provides a calibration cycle table of the main and auxiliary metering hole screws, the oil needle, the position of the oil needle and the position of the mixing ratio according to the two factors.

TABLE 1 Jingbin PWK 36S AG carburetor

Please refer to table 1, which is an adjustment cycle table of the PWK 36S AG carburetor, wherein M/FT ASL is altitude, TEMP is air temperature, ASO is counterclockwise number of turns of mixing 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. It can be seen from table 1 that the adjustment altitude range is 0 to 3000 m, the change of altitude and air temperature is insensitive and unchangeable to the adjustment of idle screw and the number of turns of mixing ratio, and is sensitive and changeable to the adjustment of oil needle type, oil needle position and main metering screw, the adjustment of auxiliary metering screw and the number of turns of mixing ratio only has the greatest influence on the condition of idle speed to 1/4 throttle valve opening, the adjustment of oil needle and oil needle position and main metering screw has the greatest influence on the 1/2 to fully open throttle valve opening, the altitude range of 0 to 3000 m basically includes all areas except the Qinghai-Tibet plateau area in China, when collecting and summarizing the inclined plane data on the fuel metering rod, the experiment from idle speed to full speed is repeatedly carried out in the atmospheric environment simulated in the laboratory with the factors of atmosphere and air temperature in the high altitude area as background, data is collected.

Laboratory simulation environment: the atmospheric pressure is: 67.24kpa ((elevation 3000 m) and air temperature of 20 ℃ (summer), taking a KTM 2016250 EXC engine as an example, after a large number of acquisition experiments, a smooth fuel metering curve is obtained, and finally a fuel metering rod is shaped, and the fuel metering rod can meet the fuel supply requirement of the engine from idle speed to full opening of a plate valve in the simulated environment.

in reality, the atmospheric pressure will rise by 10kpa every 900 m of the altitude, that is, under the condition that the plate valve 9 is fully opened, the fuel injection quantity of the fuel injection hole reaches the maximum fuel injection quantity under the negative pressure in the carburetor throat pipe in a low altitude area, and in order to keep the air-fuel ratio of 12.6-13.5, the fuel supply quantity needs to be increased in other modes. This can be achieved by adding a high-speed fuel auxiliary pump, so that if better environmental compatibility is desired, it is necessary to simulate another atmospheric environment, i.e. a standard atmospheric pressure region with an altitude of 0M, again over a large span.

Laboratory simulation environment: the laboratory simulated atmospheric pressure is: 101.3kpa (altitude 0 m), temperature: -20 ℃ (winter).

According to all specific environments in the environment periodic table, the plate valve is fully opened, the 12.6-13.5 air-fuel ratio is maintained, the fuel oil supply required by the altitude of 0 meter is the most, the power output of the engine is the strongest, and the data of the fuel oil auxiliary pump are obtained through experiments.

From the physical characteristics of the atmosphere, the atmosphere always flows from a high-pressure area to a low-pressure area at the same altitude. In the air flowing process, when the air passes through a narrow space, the flow velocity of the air is accelerated, the faster the flow velocity is, the larger the negative pressure value generated in the narrow space is, and the venturi effect is, therefore, in the channel of the carburetor, a contraction part is designed at the position of a throttle valve or in the process from the throttle valve to a port connected with an engine, the contraction part is called as a venturi tube, also called as a throat tube, and the purpose of the contraction part is to accelerate the flow velocity of the air and generate more negative pressure values, under the action of the negative pressure, the fuel is ejected from a gap generated by a fuel metering rod and an oil delivery tunnel, the larger the opening of a plate valve is, the faster the air flow velocity is, the larger the generated negative pressure value is, the more the ejected fuel is, the ejected fuel is blown into fine oil drops by the high-speed air flow to be mixed with the air flow to move forward, and the engine generates heat when running, these droplets are immediately evaporated to oil vapor and then sent to the cylinder for combustion work.

Through experiments, from low atmospheric pressure to high atmospheric pressure, the air temperature is-20 ℃, the humidity problem can be ignored, the freezing point exceeds the dew point, the air is relatively dry, under the standard atmospheric pressure and under the condition of not adding high-speed assistance, the phenomenon that the engine of the carburetor is lack of oil under the condition that the throttle valve is fully opened is found, the fuel oil quantity required by the altitude span and the temperature span can be just met by utilizing the combined action of the fuel oil assistance pump, the method is equivalent to forming an air and fuel oil sensing system, and the reasonable air-fuel ratio can be intelligently mixed according to the negative pressure value in the throat pipe of the carburetor at any time, so that the carburetor can not be sensitive to the altitude and the air temperature any more.

Referring to fig. 14, the present embodiment provides another carburetor, which is a conventional plunger type carburetor and is configured with all the components described in the first embodiment, that is, all the components described in the first embodiment can be used in the plunger type carburetor, and the principle thereof is the same as that described in the first embodiment, and will not be described herein again.

Referring to fig. 15, the present embodiment further provides another carburetor, which is a conventional vacuum diaphragm type carburetor configured with all the devices described in the first embodiment, that is, all the devices described in the first embodiment can be used in a vacuum diaphragm type carburetor, and the principle thereof is the same as that described in the first embodiment, and will not be described herein again.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims (9)

1. A carburetor provided with a fuel auxiliary pump is characterized by comprising a plurality of fuel auxiliary pumps (1) and a carburetor body (2), the carburetor body (2) comprises a float chamber (201) and an air inlet chamber (202), wherein the fuel auxiliary pump (1) communicates the float chamber (201) and the intake chamber (202), the fuel auxiliary pump (1) comprises a first opening adjusting structure (101) and a first oil delivery pipe (102), wherein the first opening adjusting structure (101) is movably arranged at the oil inlet end (2021) of the air inlet chamber (202), for adjusting the size of the opening of the oil inlet end (2021) into the inlet chamber (202), a first end of the first oil pipe (102) is connected to the float chamber (201), the second end of the first oil delivery pipe (102) is connected to the oil inlet end (2021) of the air inlet chamber (202).

2. a carburettor according to claim 1 wherein the first opening adjustment structure (101) is a first needle valve.

3. A carburettor according to claim 2 wherein the first needle valve comprises a first threaded connector (1011) and a first needle (1012), the first threaded connector (1011) having a first end fixedly connected to a first end of the first needle (1012), the first needle valve being threadedly connected to the oil inlet (2021) of the inlet chamber (202) by the first threaded connector (1011).

4. A carburettor according to claim 3 further comprising a first limit spring (3), the first needle valve further comprising a first cap (1013), a first end of the first limit spring (3) being connected to the first cap (1013), a second end of the first limit spring (3) being connected to a first port of the oil intake end (2021) of the intake chamber (202), and the first limit spring (3) being fitted over the first threaded connection (1011).

5. a carburettor according to claim 3 further comprising an oil jet connected to the second port of the oil inlet end (2021) of the inlet chamber (202).

6. A carburetor according to claim 1, further comprising a second opening adjustment structure (4) and a second oil delivery pipe (5), wherein the carburetor body (2) further comprises a mixing chamber (203), the second opening adjustment structure (4) is movably disposed in a connecting hole of a first oil inlet end (2031) of the mixing chamber (203) for adjusting the opening size of the first oil inlet end (2031), a first end of the second oil delivery pipe (5) is connected to the float chamber (201), and a second end of the second oil delivery pipe (5) is connected to the first oil inlet end (2031).

7. A carburettor according to claim 6 wherein the second opening adjustment structure (4) is a second needle valve.

8. a carburettor according to claim 7 wherein the second needle valve comprises a second threaded connector (401) and a second needle body (402), the first end of the second threaded connector (401) being fixedly connected to the first end of the second needle body (402), the second needle valve being threadedly connected to the connection bore of the first oil feed end (2031) of the mixing chamber (203) via the second threaded connector (401).

9. A carburettor according to claim 8 further comprising a second limit spring (6), the second needle valve further comprising a second cap (403), the second limit spring (6) being connected at a first end to the second cap (403), the second limit spring (6) being connected at a second end to a connection bore in the mixing chamber (203), and the second limit spring (6) being mounted on the second threaded connection (401).