Engine and operation device

Abstract

The invention discloses an engine which comprises a carburetor and a fuel tank. The carburetor is provided with an oil cup, and the oil cup is used for storing a certain amount of fuel; the carburetor is provided with a vent hole which enables an oil cup to be communicated with the atmosphere when an engine is in a using state, and a pipeline which is communicated with the atmosphere and a fuel tank at the same time is connected to the vent hole in a sealed mode. According to the scheme, the alternative engine different from the prior art is provided, and the problem that fuel leakage is prone to occurring to a carburetor when the engine is in the storage state in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to a combustion engine.

[0002] The present application also relates to a working device having different use state and storage state. BACKGROUND

[0003] The fuel supply system of an engine is a system for supplying fuel to a combustion engine, which generally comprises a fuel tank for storing fuel and a carburetor for mixing fuel with air after atomization, and a fuel pipe is communicated between the fuel tank and the carburetor, so that the fuel tank can supply fuel to the carburetor in time. The carburetor comprises a fuel cup for storing a certain amount of fuel, and the carburetor is also provided with a breather hole for balancing the pressure in the fuel cup, which is communicated with the external atmosphere to keep the pressure in the fuel cup balanced. The fuel tank is also provided with a breather hole for keeping the pressure in the fuel tank balanced with the external atmosphere. Generally, the use state of the engine is consistent with the storage state, and the fuel in the fuel cup of the carburetor will not leak from the breather hole. However, for some special working devices, the use state and the storage state of the working device are quite different, and when the working device is transformed from the use state to the storage state, the working device needs to be turned over by a certain angle, which causes the engine installed on the working device to also be turned over by a certain angle, thereby easily causing the fuel cup of the carburetor to leak. For example, the working device is a walk-behind mower for lawn mowing, which has a relatively large horizontal projection area in the use state, but has a relatively small height dimension. In order to reduce the horizontal area occupied by the walk-behind mower when it is stored, the walk-behind mower is generally turned over by 90° from the use state to the vertical storage state, which easily causes the fuel in the carburetor to leak.

[0004] European patent document EP3045030B1 discloses a vertically storable engine and lawn mower, which comprises: a gasoline engine configured to operate in a substantially horizontal orientation and to be stored in a substantially vertical orientation without leaking liquid from the gasoline engine; characterized in that the engine comprises a carburetor bowl configured to store a quantity of gasoline, and a bowl vent having a vent outlet positioned to extend above a level of the gasoline when the engine is in the vertical orientation. The prior art solves the problem of fuel leakage in the carburetor bowl by positioning the vent outlet to extend above the level of the gasoline when the engine is in the vertical orientation, so that the gasoline in the carburetor bowl will not enter the vent outlet and cause fuel leakage. Although the prior art solves the problem of fuel leakage when the engine is vertically stored, the fuel in the carburetor bowl is stored for a long time, which affects the working reliability of the carburetor, such as the problem of impurities blocking the carburetor due to fuel evaporation. SUMMARY

[0005] The present application aims to provide an alternative engine different from the prior art to solve the problem that the carburetor is prone to fuel leakage when the engine is in the storage state.

[0006] To achieve the above-mentioned purpose, the present application provides an engine comprising a carburetor and a fuel tank; the carburetor is provided with an oil cup for storing a certain amount of fuel; the carburetor is provided with a vent hole for communicating the oil cup with the atmosphere when the engine is in use, and a pipeline is sealingly connected to the vent hole and simultaneously communicates with the atmosphere and the fuel tank.

[0007] By connecting the pipeline between the vent hole and the fuel tank, when the engine is in normal use, the vent hole is communicated with the atmosphere through the pipeline, the pressure in the oil cup of the carburetor is balanced with the external atmospheric pressure, and the carburetor can work normally; when the engine is in the storage state, the fuel in the oil cup of the carburetor will be received by the pipeline when overflowing through the vent hole, thereby avoiding fuel leakage to the external environment through the vent hole; the pipeline can block the fuel entering the vent hole, thereby avoiding more fuel in the vent hole, or the pipeline guides the fuel overflowing from the vent hole into the fuel tank, thereby avoiding the problem of fuel leakage of the carburetor.

[0008] Preferably, the vent hole is located at the bottom of the oil cup of the carburetor when the engine is in the storage state. Herein, the bottom of the oil cup of the carburetor when the engine is in the storage state refers to a position near the region with the minimum gravitational potential energy in the cup opening region of the oil cup, which can make the fuel in the oil cup completely or almost completely drained. With such a configuration, the fuel in the oil cup of the carburetor is directly collected at the vent hole and drained into the pipeline under the action of gravity when the engine is in the storage state, thereby realizing automatic emptying of the oil cup. In this way, the problem of fuel leakage when the engine is in the storage state is solved, and the problem of damage to the carburetor due to long-term storage of fuel in the carburetor is also solved.

[0009] Preferably, the pipeline comprises a main pipe for communicating the vent hole with the fuel tank, and a branch pipe for communicating the main pipe with the atmosphere. With such a configuration, when the engine is in the storage state, the fuel in the oil cup flows back to the fuel tank through the main pipe; when the engine is in use, the vent hole can be kept in communication with the atmosphere through the branch pipe after the main pipe is blocked by fuel, thereby improving the reliability of the pipeline in use.

[0010] Preferably, the branch pipe is arranged close to the vent hole, and the end of the branch pipe away from the main pipe is arranged to be inclined to the carburetor. With such an arrangement, when the engine is in the storage state, the end of the branch pipe away from the main pipe is higher than the end of the branch pipe connected to the main pipe, so as to avoid fuel leakage from the branch pipe after flowing out of the carburetor, and thus the branch pipe is simple and reliable to arrange.

[0011] Preferably, the branch pipe is arranged close to the vent hole, and the end of the branch pipe away from the main pipe is arranged to be inclined to the carburetor. With such an arrangement, when the engine is in the storage state, the end of the branch pipe away from the main pipe is higher than the end of the branch pipe connected to the main pipe, so as to avoid fuel leakage from the branch pipe after flowing out of the carburetor, and thus the branch pipe is simple and reliable to arrange.

[0012] Preferably, the branch pipe is arranged close to the vent hole, and the end of the branch pipe away from the main pipe is arranged to be inclined to the carburetor. With such an arrangement, when the engine is in the storage state, the end of the branch pipe away from the main pipe is higher than the end of the branch pipe connected to the main pipe, so as to avoid fuel leakage from the branch pipe after flowing out of the carburetor, and thus the branch pipe is simple and reliable to arrange.

[0013] Preferably, the branch pipe is arranged close to the vent hole, and the end of the branch pipe away from the main pipe is arranged to be inclined to the carburetor. With such an arrangement, when the engine is in the storage state, the end of the branch pipe away from the main pipe is higher than the end of the branch pipe connected to the main pipe, so as to avoid fuel leakage from the branch pipe after flowing out of the carburetor, and thus the branch pipe is simple and reliable to arrange.

[0014] Preferably, in order to balance the effects of oil return and venting of the main pipe, the end of the main pipe communicating with the fuel tank is located inside the fuel filling port of the fuel tank.

[0015] Preferably, in order to further reduce the fuel in the fuel tank from entering the pipeline, a liquid level separation part for blocking fuel from entering the main pipe is arranged at the fuel filling port of the fuel tank.

[0016] Preferably, in order to further reduce the fuel in the fuel tank from flowing to the carburetor through the pipeline, a gas-liquid separation part cooperating with the main pipe is arranged at the fuel filling port of the fuel tank, and the gas-liquid separation part is provided with a tortuous vent passage communicating with the main pipe.

[0017] Preferably, in order to further simplify the structure, an oil level indicator is arranged at the fuel filling port of the fuel tank, and the liquid level separation part and the gas-liquid separation part are integrally formed with the oil level indicator.

[0018] Preferably, in order to further avoid the fuel in the fuel tank from flowing to the carburetor through the pipeline, the main pipe comprises a liquid storage section and a liquid blocking section, both of which are located between the branch pipe and the fuel tank, the liquid storage section is located between the liquid blocking section and the fuel tank, and the liquid blocking section is located on the upper side of the liquid storage section.

[0019] Preferably, the liquid storage section is in a U shape.

[0020] Preferably, the end of the pipeline connected to the fuel tank is higher than the rated maximum liquid level in the fuel tank, and the fuel tank is provided with a vent that connects the space above the rated maximum liquid level in the fuel tank to the atmosphere. With this arrangement, the pipeline is connected to the cavity above the rated maximum liquid level in the fuel tank, and simultaneously, the cavity above the rated maximum liquid level in the fuel tank is connected to the atmosphere through the vent. This ensures that the pipeline remains connected to the atmosphere through the cavity above the rated maximum liquid level in the fuel tank, thus simplifying the pipeline structure and facilitating its manufacturing.

[0021] Preferably, the venting section includes a vent that connects the space above the rated maximum liquid level in the fuel tank to the atmosphere.

[0022] The present invention also provides a working device, including any of the engines described above.

[0023] The present invention has the following beneficial effects: Compared with the prior art, the present invention simultaneously solves the problems of fuel leakage and fuel corrosion damage to the carburetor when the engine is in the retracted state. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an embodiment of the working device of the present invention in use; Figure 2 This is a schematic diagram of an embodiment of the working device of the present invention in a stowed state; Figure 3 for Figure 1 A schematic diagram of the engine in operation; Figure 4 for Figure 2 A schematic diagram of the engine in its retracted state; Figure 5 for Figure 3 Schematic diagram of the oil level indicator; Figure 6 for Figure 4 Bottom view of the Chinese carburetor; Figure 7 for Figure 6 Sectional view of AA. Detailed Implementation

[0025] A fuel level indicator is a component installed at the fuel filler neck to mark the maximum rated capacity of the fuel tank. When the fuel level in the fuel tank reaches the bottom of the fuel level indicator, it indicates that the fuel in the fuel tank has reached the maximum rated capacity.

[0026] A tortuous airway refers to an airway that is not straight but is formed by multiple bends.

[0027] The liquid surface separation part is used to separate the liquid surface at the fuel filling port into several small liquid surfaces, so as to reduce the impact force of the liquid surface.

[0028] The specific embodiments are described in further detail below: The reference signs in the drawings of the specification include: a frame 1, an engine 2, an engine body 21, a carburetor 22, an oil cup 221, a breather hole 222, a pipeline 23, a main pipe 231, a branch pipe 232, a liquid blocking section 2311, a liquid storage section 2312, a fuel tank 24, an oil level indicator 241, a fuel filling port 242, an oil return port 243, a gas-liquid separation part 244, a zigzag breather 245, a liquid surface separation part 246, a rated maximum liquid surface 247, and a fuel supply pipe 25.

[0029] Embodiment: As shown in Figure 1 and Figure 2 , a working device includes a frame 1 and an engine 2, and the engine 2 is installed on the frame 1. In this embodiment, the working device is a walking mower. Of course, in other embodiments, the working device can also be a snow blower, a concrete trowel, etc., and the use state of the working device is the state when the frame 1 is placed horizontally (as shown in Figure 1 ), and the storage state of the working device is the state when the frame 1 is placed vertically (as shown in Figure 2 ). When the working device is switched from the use state to the storage state, the frame 1 needs to be turned by 90°, and thus the engine 2 installed on the frame 1 is also turned by 90°.

[0030] As shown in Figure 3 , the engine 2 includes an engine body 21 mainly composed of a cylinder and a crankcase, and further includes a carburetor 22 and a fuel tank 24, and the carburetor 22 and the fuel tank 24 are connected and supported on the engine body 21. When the engine 2 is in the use state (as shown in Figure 3 ), the carburetor 22 and the fuel tank 24 are distributed around the engine body 21 along the horizontal plane; when the engine 2 is in the storage state (as shown in Figure 4 ), the fuel tank 24 is located below the engine body 21, and the carburetor 22 is located horizontally aside the engine body 21 and is higher than the fuel tank 24.

[0031] The carburetor 22 is provided with a fuel cup 221 and a vent hole 222, and a fuel supply pipe 25 is connected between the carburetor 22 and a fuel tank 24, which supplies fuel to the carburetor 22. In order to control the fuel supply of the fuel supply pipe 25 and avoid excessive fuel supply to the carburetor 22, a valve is provided on the carburetor 22 and connected with the fuel supply pipe 25, and a float is arranged in the fuel cup 221 of the carburetor 22 to control the opening and closing of the valve. The density of the float is less than that of the fuel, and the float rises and falls with the liquid level of the fuel in the fuel cup 221. When the liquid level of the fuel in the fuel cup 221 drops due to fuel consumption, the float opens the valve to allow the fuel supply pipe 25 to supply fuel to the fuel cup 221 when the liquid level drops to a certain position. When the fuel in the fuel cup 221 gradually fills up and the liquid level rises, the float also rises to a certain position, and the float controls the valve to close, so that the fuel supply pipe 25 stops supplying fuel to the fuel cup 221. When the engine 2 is in use, the carburetor 22 is also in normal use, and at this time, the vent hole 222 of the carburetor 22 is located above the fuel cup 221, so that the part of the fuel cup 221 not filled with fuel is in communication with the vent hole 222. When the gas pressure in the fuel cup 221 changes, the vent hole 222 can be used to adjust in time to keep the pressure in the fuel cup 221 balanced.

[0032] The vent hole 222 is sealingly connected with a pipe 23, which is in communication with the atmosphere and the fuel tank 24. The pipe 23 is used to communicate the fuel cup with the atmosphere when the engine 2 is in use, and is also used to prevent the fuel in the fuel cup from leaking to the outside of the engine 2 when the engine 2 is in storage. In this embodiment, the vent hole 222 is located at the bottom of the fuel cup 221 of the carburetor 22 when the engine 2 is in storage. More preferably, the vent hole 222 is located at the lowest position of the fuel cup 221 of the carburetor 22 when the engine 2 is in storage (as shown in Figure 4 、 Figure 6 and Figure 7 , so that the fuel in the fuel cup 221 is collected and discharged towards the vent hole 222 under the action of gravity until the fuel cup 221 is emptied.

[0033] As shown in Figure 3 and Figure 4As shown, in the embodiment, the pipeline 23 includes a main pipe 231 connecting the vent hole 222 and the fuel tank 24, and the pipeline 23 further includes a branch pipe 232 connecting the main pipe 231 and the atmosphere. In order to facilitate processing, the branch pipe 232 is connected with the main pipe 231 through a tee joint. Of course, in other embodiments, the branch pipe 232 and the main pipe 231 can be provided in an integrated manner. The branch pipe 232 is arranged close to the vent hole 222, and an end of the branch pipe 232 away from the main pipe 231 is arranged to be deviated towards the carburetor 22, so that when the engine 2 is in the storage state, the end of the branch pipe 232 away from the main pipe 231 is higher than the other end of the branch pipe 232, so that the fuel in the oil cup 221 entering the main pipe 231 through the vent hole 222 cannot enter the branch pipe 232, thereby avoiding fuel leakage through the branch pipe 232. Specifically, the included angle between the branch pipe 232 and the end of the main pipe 231 connecting the vent hole 222 ranges from 20° to 90°. In the embodiment, the included angle between the branch pipe 232 and the main pipe 231 is preferably 30°. In other embodiments, the included angle between the branch pipe 232 and the main pipe 231 can also be 20°, 40°, 50°, 60°, 70°, 80°, 90°, etc.

[0034] As shown in Figure 3 , the end of the main pipe 231 communicating with the fuel tank 24 is higher than the rated maximum liquid level 247 in the fuel tank 24, so that the end of the main pipe 231 communicating with the fuel tank 24 is always located in the space above the fuel liquid level. The rated maximum liquid level 247 of the fuel tank 24 refers to the horizontal plane of the highest fuel liquid level when the fuel tank 24 is filled with fuel under the normal use state specified in the design. The end of the main pipe 231 communicating with the fuel tank 24 is located inside the fuel filling port 242. In the embodiment, the main pipe 231 penetrates the shell of the fuel tank 24 from the position close to the fuel filling port 242 of the fuel tank 24, and then extends to the fuel filling port 242 in the fuel tank 24.

[0035] As shown in Figure 3 and Figure 5 , the fuel filling port 242 of the fuel tank 24 is provided with a liquid level separation portion 246 for blocking fuel from entering the main pipe 231. The fuel filling port 242 of the fuel tank 24 is provided with a gas-liquid separation portion 244 cooperating with the main pipe 231, and the gas-liquid separation portion 244 is provided with a tortuous vent passage 245 communicating with the main pipe 231. The main pipe 231 communicates with the inside of the fuel tank 24 through the gas-liquid separation portion 244 and the tortuous vent passage 245, so as to further block the fuel in the fuel tank 24 from entering the main pipe 231. The fuel filling port 242 of the fuel tank 24 is provided with an oil level indicator 241, and the liquid level separation portion 246 and the gas-liquid separation portion 244 are integrally formed with the oil level indicator 241. The oil level indicator 241 is provided with a return oil port 243 communicating with the main pipe 231.

[0036] AsFigure 3 and Figure 4 As shown in FIG. 2, the main pipe 231 includes a liquid storage section 2312 and a liquid blocking section 2311, both of which are located between the branch pipe 232 and the fuel tank 24, the liquid storage section 2312 is located between the liquid blocking section 2311 and the fuel tank 24, and the liquid blocking section 2311 is located on the upper side of the liquid storage section 2312. No matter whether the engine 2 is in the use state or the storage state, the liquid blocking section 2311 can prevent the fuel entering the liquid storage section 2312 from flowing through the liquid blocking section 2311 and towards the carburetor 22. The liquid storage section 2312 is used for temporarily storing the fuel entering the main pipe 231 from the fuel tank 24 in an extreme case. The liquid storage section 2312 is U-shaped, specifically, it is naturally formed by bending through a partial area of the main pipe 231. When the engine 2 is in the storage state, the end of the liquid storage section 2312 connected with the liquid blocking section 2311 is higher than the end of the liquid storage section 2312 connected with the fuel tank 24, so that the fuel in the liquid storage section 2312 flows from the liquid blocking section 2311 towards the fuel tank 24, and the fuel backflows into the fuel tank 24, avoiding long-term storage of the fuel in the liquid storage section 2312.

[0037] The specific implementation process is as follows: when the working device is in the use state, i.e., the engine 2 is in the use state, the oil cup 221 of the carburetor 22 is in communication with the atmosphere through the vent hole 222, the main pipe 231 and the branch pipe 232, so that the carburetor 22 can work normally; when the working device is in the storage state, i.e., the engine 2 is in the storage state, the fuel in the oil cup 221 of the carburetor 22 backflows into the fuel tank 24 through the vent hole 222 and the main pipe 231, which not only avoids the problem of fuel leakage when the engine 2 is in the storage state, but also avoids the problem of corrosion and damage of the carburetor 22 due to long-term storage of the fuel in the carburetor 22.

[0038] In another embodiment, the end of the pipeline 23 connected with the fuel tank 24 is higher than the rated maximum liquid level 247 in the fuel tank 24, and the fuel tank 24 is provided with a venting portion for communicating the space above the rated maximum liquid level 247 in the fuel tank 24 with the atmosphere. The venting portion includes a vent hole for communicating the space above the rated maximum liquid level 247 in the fuel tank 24 with the atmosphere. Thus, when the working device is in the use state, i.e., the engine 2 is in the use state, the oil cup 221 of the carburetor 22 is in communication with the atmosphere through the vent hole 222, the pipeline 23, the space above the rated maximum liquid level 247 in the fuel tank 24 and the vent hole of the fuel tank 24, achieving pressure balance in the oil cup 221; when the working device is in the storage state, i.e., the engine 2 is in the storage state, the fuel in the oil cup 221 backflows into the fuel tank 24 through the vent hole 222 and the pipeline 23, achieving emptying of the oil cup 221.

[0039] The above-mentioned are only embodiments of the present application, and the common knowledge of specific structures and characteristics in the scheme is not described in detail. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should be considered as the protection scope of the present application, and these will not affect the effect and practicality of the patent.

Claims

1. An engine comprising a carburetor and a fuel tank; the carburetor being provided with a fuel cup for storing a certain amount of fuel; the carburetor being provided with a vent for communicating the fuel cup with the atmosphere when the engine is in operation, characterized in that: The vent is sealed with a pipe that connects to both the atmosphere and the fuel tank.

2. The engine according to claim 1, characterized in that: The vent is located at the bottom of the carburetor's fuel cup when the engine is in the retracted position.

3. The engine according to claim 1 or 2, characterized in that: The pipeline includes a main pipe connecting the vent to the fuel tank, and a branch pipe connecting the main pipe to the atmosphere.

4. The engine according to claim 3, characterized in that: The branch pipe is positioned near the vent, and the end of the branch pipe furthest from the main pipe is positioned towards the carburetor.

5. The engine according to claim 4, characterized in that: The included angle between the branch pipe and the end of the main pipe connected to the vent hole ranges from 20° to 90°.

6. The engine according to claim 5, characterized in that: The branch pipe is connected to the main pipe via a multi-port connector.

7. The engine according to any one of claims 3 to 6, characterized in that: The end of the main pipe that connects to the fuel tank is higher than the highest liquid level in the fuel tank.

8. The engine according to claim 7, characterized in that: The end of the main pipe that connects to the fuel tank is located inside the fuel filling port of the fuel tank.

9. The engine according to claim 8, characterized in that: The fuel tank has a liquid level divider at the fuel filling port to prevent fuel from entering the main pipe.

10. The engine according to claim 9, characterized in that: The fuel tank is equipped with a gas-liquid separator that works in conjunction with the main pipe at the fuel filling port. The gas-liquid separator is provided with a tortuous vent that communicates with the main pipe.

11. The engine according to claim 10, characterized in that: The fuel tank is equipped with an oil level indicator at the fuel filling port, and the liquid level separator and the gas-liquid separator are integrally formed with the oil level indicator.

12. The engine according to claim 3, 4, 5, 6, 8, 9, 10 or 11, characterized in that: The main pipe includes a liquid storage section and a liquid blocking section, both of which are located between the branch pipe and the fuel tank. The liquid storage section is located between the liquid blocking section and the fuel tank, and the liquid blocking section is located above the liquid storage section.

13. The engine according to claim 12, characterized in that: The liquid storage section is U-shaped.

14. The engine according to claim 1, characterized in that: One end of the pipeline that connects to the fuel tank is higher than the rated maximum liquid level in the fuel tank, and the fuel tank is provided with a vent that connects the space above the rated maximum liquid level in the fuel tank to the atmosphere.

15. The engine according to claim 14, characterized in that: The venting section includes a vent that connects the space above the rated maximum liquid level in the fuel tank to the atmosphere.

16. A working device, characterized in that: Includes the engine as described in any one of claims 1 to 15.

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