Non-road engine

Abstract

The non-road type engine comprises a carburetor and a combination switch used for controlling connection and disconnection of an oil supply pipeline between an oil tank and the carburetor, a control valve used for controlling opening and closing of a main metering jet is arranged on the carburetor, and the control valve is in linkage fit with the combination switch; when the combined switch is in an on state, the control valve enables the main metering jet to be in a conducting state; and when the combined switch is in a closed state, the control valve enables the main metering jet to be in a closed state. According to the scheme, the problem of how to reduce the dumping oil leakage risk of the non-road type engine in the prior art is solved, so that the non-road type engine better meets the environmental protection requirement.

Description

Technical Field

[0001] The present invention relates to non-road engines. Background Art

[0002] Non-road engines refer to engines that are not used for vehicles, such as engines used in power generation equipment such as generators, and engines used in gardening equipment such as lawn mowers. They all belong to non-road engines. In some areas, separate environmental protection standards have been formulated for non-road engines, especially strict requirements have been made for indicators such as oil leakage and evaporative emissions of non-road engines. The components of existing non-road engines include carburetors, fuel tanks, air filters, engine cylinders, crankcases, and various connecting pipes. The previous environmental protection requirements stipulated the oil leakage of the fuel tank after the engine was dumped, so the existing technology mainly focused on improving the direction of preventing oil leakage from the fuel tank. With the improvement of environmental protection requirements, regulations are now also made for the oil leakage of non-road engines after dumping when the whole machine is in a stopped state. Therefore, how to reduce the risk of oil leakage after the non-road engine is dumped in a stopped state has become a technical problem that urgently needs to be solved. Summary of the invention

[0003] The object of the present invention is to provide a non-road engine to solve the problem of how to reduce the risk of oil leakage of the non-road engine in the prior art.

[0004] In order to achieve the above-mentioned purpose, the basic scheme of the present invention provides a non-road engine, including a carburetor, and also including a combination switch for controlling the on-off of the oil supply pipeline between the fuel tank and the carburetor. The carburetor is provided with a control valve for controlling the opening and closing of the main metering orifice, and the control valve is linked with the combination switch; when the combination switch is in an open state, the control valve puts the main metering orifice in a conducting state; when the combination switch is in a closed state, the control valve puts the main metering orifice in a closed state.

[0005] The beneficial effect of this basic scheme is that: by adopting such a setting, when the combination switch is turned on, the control valve also makes the main metering hole of the carburetor in an open state, so that the non-road engine can work normally; when the non-road engine is stopped, the combination switch is closed in linkage, and the combination switch is linked to cut off the fuel supply between the fuel tank and the carburetor, and the control valve also makes the main metering hole of the carburetor in a closed state, so that the fuel in the carburetor cannot be discharged through the main metering hole, so when the non-road engine is tipped over, the fuel in the carburetor will not be discharged from the main metering hole into the intake pipe of the non-road engine and leak, and because the fuel supply between the fuel tank and the carburetor is cut off, even after the control valve switch fails, the fuel in the fuel tank will not leak out through the oil path between the fuel tank and the carburetor, thereby greatly avoiding the fuel leakage after the non-road engine is tipped over, and thereby making the tipping oil leakage index meet the environmental protection requirements. In addition, such a setting is also conducive to reducing the evaporative emissions of the non-road engine, thereby further making the evaporative emission performance of the non-road engine easier to meet the environmental protection requirements.

[0006] Preferably, the linkage between the control valve and the combination switch is mechanical. This arrangement can reduce the influence of factors such as engine heat on the linkage between the control valve and the combination switch, thereby facilitating the improvement of the reliability of the linkage.

[0007] Preferably, the control valve includes a needle valve stem matched with the end of the main orifice, and the combination switch has a movable part for controlling the opening and closing of the switch, and the movable part and the needle valve stem are linked by a cable. With such an arrangement, the linkage between the combination switch and the control valve is realized by the cable, thereby reducing the interference of other parts of the engine on the linkage between the combination switch and the control valve, which is conducive to assembly and arrangement.

[0008] Preferably, the control valve is provided with a return spring which makes the needle valve stem have a tendency to close the main metering orifice. With such an arrangement, when the needle valve stem is not subjected to the tension of the cable, the return spring is used to keep the main metering orifice in a closed state, thereby facilitating the closing operation of the main metering orifice.

[0009] Preferably, an elastic sealing member is provided between the needle valve stem and the oil storage chamber of the carburetor. Such a configuration is helpful to avoid oil leakage at the needle valve stem.

[0010] Preferably, the elastic seal is annular, and the cross section of the elastic seal is an arc groove. When the needle valve stem closes the main metering hole, the elastic seal is in a normal shape. With such a configuration, the elastic seal is in a stress-free state when the machine is stopped, which is beneficial to prolonging the service life of the elastic seal.

[0011] Preferably, the control valve is an electronically controlled valve, and the combination switch is provided with a circuit switch electrically connected to the control valve. With such a setting, the linkage setting between the combination switch and the control valve is simplified, thereby further reducing the interference of other components.

[0012] Preferably, the control valve includes a solenoid valve for controlling the movement of the needle valve stem, and the circuit switch is electrically connected to the solenoid valve. With such an arrangement, the movement of the needle valve stem is controlled by the circuit switch and the solenoid valve, which is conducive to further simplifying the structure.

[0013] Preferably, the balance hole of the carburetor is an external balance hole, and the opening of the balance hole is arranged toward the upper part of the carburetor. With such an arrangement, the fuel discharged through the balance hole when the engine is tipped over can be reduced, thereby facilitating further reduction of evaporative emissions of the non-road engine.

[0014] The beneficial effect of this solution is that when the non-road engine is shut down, the combination switch cuts off the fuel supply between the fuel tank and the carburetor and also closes the main metering orifice of the carburetor, thereby significantly reducing the risk of oil leakage after the non-road engine is tipped over. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a non-road engine embodiment of the present invention in which a combination switch cooperates with a carburetor and the combination switch is in an on state; Figure 2 for Figure 1 Schematic diagram of the combination switch in the off state; Figure 3 for Figure 1 Schematic diagram of the cooperation between the middle needle valve stem and the elastic seal; Figure 4 Schematic diagram of the position of the balancing hole in the present invention. DETAILED DESCRIPTION

[0016] In the present invention, the "normal shape" refers to the shape of the elastic sealing member when it is not stressed.

[0017] The following is further described in detail through specific implementation methods: The reference numerals in the drawings of the specification include: carburetor 1, oil storage chamber 2, main metering orifice 3, needle valve stem 4, elastic sealing member 5, valve body shell 6, return spring 7, cable 8, combination switch 9, movable member 10, balance hole 11.

[0018] The embodiment is basically as shown in the attached Figures 1 to 4As shown: a non-road engine, including a carburetor 1 and a combination switch 9 for controlling the on and off of the oil supply pipeline between the fuel tank and the carburetor. The carburetor 1 is provided with a control valve for controlling the opening and closing of the main metering hole 3, and the control valve cooperates with the combination switch 9; when the combination switch 9 is in the open state, the control valve makes the main metering hole 3 in the conducting state; when the combination switch 9 is in the closed state, the control valve makes the main metering hole 3 in the closed state. Specifically, the control valve includes a valve body shell 6, and the valve body shell 6 is fixed to the carburetor 1 by bolts; the control valve also includes a needle valve rod 4 that cooperates with the end of the main metering hole 3 of the carburetor 1, and the needle valve rod 4 can switch between the combined state and the separated state with the end of the main metering hole 3 under the sliding support of the valve body shell 6, so as to realize the closing and conducting of the main metering hole 3. The control valve is provided with a return spring 7 that makes the needle valve rod 4 have a tendency to keep the main metering hole 3 closed.

[0019] In this embodiment, the control valve and the combination switch 9 are mechanically linked. Specifically, a pull buckle is provided at the end of the needle valve stem 4, and a cable 8 is connected to the pull buckle. By pulling the cable 8, the needle valve stem 4 can be pulled to move. In this embodiment, the structure of the cable 8 is similar to the structure of the clutch line in the prior art, and is composed of a steel wire and a wire sleeve that is slidably sleeved on the outside of the steel wire. The combination switch 9 has a movable part 10 for controlling the opening and closing of the switch, and the movable part 10 is connected to the cable 8 to realize the pulling control of the cable 8. In this embodiment, the combination switch 9 is a knob-type switch, and the movable part 10 is a knob for controlling the opening and closing of the switch. The knob is connected to the cable 8, so that the pulling operation of the cable 8 can be realized by turning the knob.

[0020] In order to avoid oil leakage at the needle valve stem 4, an elastic seal 5 is provided between the needle valve stem 4 and the oil storage chamber 2 of the carburetor 1. In this embodiment, the elastic seal 5 is annular, and the cross section of the elastic seal 5 is in the shape of an arc groove; the inner edge of the elastic seal 5 is sealed and connected to the needle valve stem 4, and the outer edge is connected between the oil storage chamber 2 of the carburetor 1 and the valve body shell 6 of the control valve. The oil storage chamber 2 in this embodiment is formed by an oil cup arranged at the bottom of the carburetor 1. When the needle valve stem 4 closes the main metering orifice 3, the elastic seal 5 is in a normal shape, which is conducive to extending the service life of the elastic seal 5. The balance hole 11 of the carburetor 1 is an external balance hole 11, and is arranged toward the upper part of the carburetor 1, so that the opening of the balance hole 11 is away from the ground.

[0021] The specific implementation process is as follows: when the engine needs to be started, the combination switch 9 is turned on by rotating the knob of the combination switch 9. When the knob is rotated, the needle valve stem 4 of the control valve is pulled by the cable 8 to move away from the main metering hole 3, so that the needle valve stem 4 opens the main metering hole 3 of the carburetor 1, so that the main metering hole 3 can be normally filled with oil. When the engine is turned off, the combination switch 9 is turned off by rotating the knob of the combination switch 9. When the knob is rotated, the pulling effect on the cable 8 is gradually removed, so that the needle valve stem 4 of the control valve moves toward the main metering hole 3 under the action of the return spring 7, and finally the needle valve stem 4 blocks the end of the main metering hole 3, so that the main metering hole 3 is closed. Therefore, when the non-road engine is overturned, the fuel in the carburetor will not be discharged from the main metering hole into the intake pipe of the non-road engine and leak. The adoption of this scheme can significantly reduce the evaporative emissions of the non-road engine. In actual use, the combination switch can also integrate the engine flameout control function, so that the combination switch can control the engine flameout while also cutting off the fuel supply between the fuel tank and the carburetor.

[0022] In other embodiments, the control valve is an electronically controlled valve, and the combination switch 9 is provided with a circuit switch electrically connected to the control valve. Specifically, the control valve includes a solenoid valve for controlling the movement of the needle valve stem 4, and the circuit switch is electrically connected to the solenoid valve. By rotating the knob of the combination switch 9, the on and off of the control circuit switch can be realized, thereby realizing the control of the solenoid valve.

[0023] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A non-road engine, comprising a carburetor, characterized in that: It also includes a combination switch for controlling the on and off of the oil supply pipeline between the oil tank and the carburetor. The carburetor is provided with a control valve for controlling the opening and closing of the main metering orifice, and the control valve is linked with the combination switch; when the combination switch is in the on state, the control valve puts the main metering orifice in the on state; when the combination switch is in the off state, the control valve puts the main metering orifice in the off state.

2. A non-road engine according to claim 1, characterized in that: The control valve and the combination switch are mechanically linked.

3. A non-road engine according to claim 2, characterized in that: The control valve comprises a needle valve stem matched with the end of the main metering orifice, and the combination switch comprises a movable part for controlling the opening and closing of the switch, and the movable part is linked with the needle valve stem through a cable.

4. A non-road engine according to claim 3, characterized in that: The control valve is provided with a return spring which makes the needle valve stem have a tendency to keep the main metering orifice closed.

5. A non-road engine according to claim 3 or 4, characterized in that: An elastic sealing member is arranged between the needle valve rod and the oil storage chamber of the carburetor.

6. A non-road engine according to claim 5, characterized in that: The elastic seal is annular, and the cross section of the elastic seal is in an arc groove shape. When the needle valve stem closes the main metering orifice, the elastic seal is in a normal shape.

7. A non-road engine according to claim 1, characterized in that: The control valve is an electronically controlled valve, and the combination switch is provided with a circuit switch electrically connected to the control valve.

8. A non-road engine according to claim 7, characterized in that: The control valve comprises a solenoid valve for controlling the movement of a needle valve stem, and the circuit switch is electrically connected to the solenoid valve.

9. A non-road engine according to any one of claims 1 to 4, characterized in that: The balancing hole of the carburetor is an external balancing hole, and the opening of the balancing hole is arranged toward the upper part of the carburetor.

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