Protection structure of oil tank and engine and engine assembly

Abstract

The utility model discloses an oil tank and engine protection structure and an engine assembly, the protection structure comprises an upper cavity and a lower cavity, an air inlet of the upper cavity is connected with the oil tank, an air outlet of the upper cavity is connected with an air inlet manifold of the engine, a labyrinth baffle is arranged in the upper cavity, and an air outlet of the labyrinth baffle is connected with an air inlet manifold of the engine. The labyrinth baffle is located between the air inlet and the air outlet, air holes are formed in the labyrinth baffle, the lower cavity is communicated with the upper cavity, and an oil return opening of the lower cavity is connected with the oil tank. The protection structure is particularly suitable for a hybrid vehicle type, when a user electrically drives the fuel tank for a long time to generate excessive fuel steam, the maze baffle of the protection structure can prevent the fuel steam from forming oil drops and flowing back to the fuel tank, and the fuel tank is prevented from being damaged due to overpressure; when a user uses fuel oil power, the labyrinth baffle can prevent liquid fuel oil from entering the intake manifold, and then the problem that gasoline burns in the intake manifold is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of automobiles, in particular to a protective structure of an oil tank and an engine and an engine assembly. Background Art

[0002] For hybrid models, users use electric driving, which causes the engine to not work for a long time, and the fuel vapor in the fuel tank is retained in the fuel tank system for a long time. A large amount of fuel vapor exceeds the adsorption capacity of the carbon canister, resulting in problems such as overpressure in the fuel tank and oil and gas leakage. In addition, for the direct injection type of injection, the engine intake manifold is usually made of plastic, but care must be taken to prevent liquid fuel from entering the intake manifold, causing gasoline to burn in the intake manifold, and then causing problems such as melting and bursting of the intake manifold. Utility Model Content

[0003] In view of this, the utility model aims to provide a fuel tank and engine protection structure and an engine assembly to solve at least one of the technical problems in the prior art, such as long-term retention of fuel vapor in the fuel tank system and easy entry of liquid fuel into the intake manifold.

[0004] The utility model provides a protective structure for a fuel tank and an engine, comprising an upper cavity and a lower cavity, wherein an air inlet of the upper cavity is connected to the fuel tank, an air outlet of the upper cavity is connected to an intake manifold of the engine, a labyrinth baffle is arranged in the upper cavity, the labyrinth baffle is located between the air inlet and the air outlet, air holes are arranged on the labyrinth baffle, the lower cavity is communicated with the upper cavity, and an oil return port of the lower cavity is connected to the fuel tank.

[0005] Furthermore, a plurality of groups of the labyrinth baffles are sequentially arranged between the air inlet and the air outlet, wherein each group of the labyrinth baffles blocks the oil and gas once.

[0006] Furthermore, at least one group of the labyrinth baffles is provided with a breathable gap.

[0007] Furthermore, the ventilation holes include a first circular hole and a second strip-shaped hole, and the first hole and the second hole are respectively provided on two adjacent groups of the maze baffles.

[0008] Furthermore, from the air inlet to the air outlet, the inner diameters of the first holes on the multiple groups of the labyrinth baffles gradually decrease; from the air inlet to the air outlet, the widths of the second holes on the multiple groups of the labyrinth baffles gradually decrease.

[0009] Furthermore, it also includes a solenoid valve, which is located between the air outlet of the upper cavity and the intake manifold.

[0010] Furthermore, a leakage plate is provided between the upper cavity and the lower cavity, the leakage plate is provided with leakage holes, and the upper cavity is connected with the lower cavity through the leakage holes.

[0011] Furthermore, a one-way valve is provided at the oil return port, a liquid baffle is provided in the lower cavity, the liquid baffle divides the lower cavity into a double-layer structure, and an oil passage port is provided on the liquid baffle.

[0012] Furthermore, the liquid baffle is a funnel structure having a concave portion, and the oil passage port is arranged at the concave portion of the funnel structure.

[0013] The utility model also provides an engine assembly, comprising the oil tank and the engine protection structure.

[0014] The protective structure of the utility model has an air inlet connected to the fuel tank, so that gaseous and liquid fuel enter the upper cavity, and the liquid and part of the gaseous fuel contact the labyrinth baffle and cool to form oil droplets, which eventually flow into the lower cavity, and the liquid fuel can be sent back to the fuel tank through the oil return port, while the remaining gaseous fuel finally enters the intake manifold from the air outlet through the air vent. The utility model is particularly suitable for hybrid vehicles. When the user drives the vehicle for a long time, the fuel tank generates too much fuel vapor, and the labyrinth baffle of the protective structure can prevent the fuel vapor from forming oil droplets and flowing back to the fuel tank. box, avoiding damage to the fuel tank due to overpressure; when the user uses fuel power, the labyrinth baffle can prevent liquid fuel from entering the intake manifold, thereby avoiding the problem of gasoline burning in the intake manifold, which is conducive to use with the intake manifold made of plastic material to ensure that the intake manifold will not fail due to high combustion temperature; because the labyrinth baffle blocks the liquid fuel and allows the liquid fuel to flow into the lower cavity, ensuring that the liquid fuel can flow back to the fuel tank from the return port, blocking the faster-flowing fuel vapor, it has a certain silencing and energy-reducing effect, and can reduce noise.

[0015] The engine assembly of the utility model has all the beneficial effects of the above-mentioned protection structure, which will not be described in detail here.

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The same reference numerals with letter suffixes or different letter suffixes may represent different instances of similar parts. The drawings generally illustrate various embodiments by way of example and not limitation, and together with the specification and claims, are used to illustrate the disclosed embodiments. When appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present apparatus or method. The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 It is a schematic diagram of the interconnection of the fuel tank, the engine and the protective structure provided by the utility model;

[0019] Figure 2 This is one of the schematic diagrams of the protective structure of the fuel tank and the engine provided by the utility model;

[0020] Figure 3 This is the second schematic diagram of the protective structure of the fuel tank and the engine provided by the utility model;

[0021] Figure 4 The third schematic diagram of the protective structure of the fuel tank and the engine provided by the utility model;

[0022] Figure 5 The fourth schematic diagram of the protection structure of the fuel tank and the engine provided by the utility model;

[0023] Figure 6 It is the fifth schematic diagram of the protective structure of the fuel tank and the engine provided by the utility model.

[0024] The above drawings include the following reference numerals:

[0025] 1. Upper cavity; 11. Air inlet; 12. Air outlet; 13. Labyrinth baffle; 131. First baffle group; 132. Second baffle group; 133. Third baffle group; 134. Fourth baffle group; 135. Fifth baffle group; 14. First air permeability gap; 15. Second air permeability gap; 16. Third air permeability gap; 17. First hole; 18. Second hole; 2. Lower cavity; 21. Oil return port; 22. Liquid baffle plate; 221. Oil pass port; 3. Solenoid valve; 4. Leakage plate; 41. Leakage hole; 100. Fuel tank; 200. Intake manifold; 300. Protection structure; 400. Carbon canister. DETAILED DESCRIPTION

[0026] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, but are not intended to limit the present invention.

[0027] It should be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the utility model will occur to those skilled in the art.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] This specification may use the phrases "in one embodiment", "in another embodiment", "in yet another embodiment" or "in other embodiments", all of which may refer to one or more of the same or different embodiments according to the present invention.

[0030] The utility model provides a protective structure 300 for a fuel tank 100 and an engine, comprising an upper cavity 1 and a lower cavity 2, wherein an air inlet 11 of the upper cavity 1 is connected to the fuel tank 100, and an air outlet 12 of the upper cavity 1 is connected to an intake manifold 200 of the engine, a labyrinth baffle 13 is provided in the upper cavity 1, and the labyrinth baffle 13 is located between the air inlet 11 and the air outlet 12, and air holes are provided on the labyrinth baffle 13, the lower cavity 2 is communicated with the upper cavity 1, and an oil return port 21 of the lower cavity 2 is connected to the fuel tank 100.

[0031] Combination Figure 1 As shown, a carbon canister 400 is usually provided on the fuel tank 100. The fuel in the fuel tank 100 is first adsorbed by the carbon canister 400 and then enters the protective structure 300 of the utility model through the air inlet 11 of the upper cavity 1, wherein the gaseous fuel enters the intake manifold 200 from the air outlet 12 of the upper cavity 1.

[0032] Combination Figures 2 to 5As shown, the fuel vapor (also referred to as oil gas) formed by the mixture of gaseous fuel and liquid fuel enters the upper cavity 1 from the air inlet 11 of the upper cavity 1, and a labyrinth baffle 13 (the number of the labyrinth baffles 13 can be one or more) is arranged between the air inlet 11 and the air outlet 12. The labyrinth baffle 13 is provided with air holes so that the gaseous fuel can pass through the air holes, and the liquid fuel is blocked by the labyrinth baffle 13. Finally, the liquid fuel falls into the lower cavity 2 due to gravity, and the gaseous fuel enters the intake manifold 200 from the air outlet 12. The oil return port 21 of the lower cavity 2 is connected to the fuel tank 100, so that the liquid fuel can return to the fuel tank 100 again.

[0033] The protective structure 300 of the present invention has an air inlet 11 connected to the fuel tank 100, so that gaseous and liquid fuel enter the upper cavity 1, and the liquid and part of the gaseous fuel contact the labyrinth baffle 13 and cool to form oil droplets, which eventually flow into the lower cavity 2, and the liquid fuel can be returned to the fuel tank 100 through the oil return port 21, while the remaining gaseous fuel finally enters the intake manifold 200 from the air outlet 12 through the air vent. The present invention is particularly suitable for hybrid vehicles. When the user drives the vehicle for a long time and the fuel tank 100 generates too much fuel vapor, the labyrinth baffle 13 of the protective structure 300 can prevent the fuel vapor from forming oil droplets and flowing back to the fuel tank 100, thereby avoiding Prevent the fuel tank 100 from being damaged by overpressure; when the user uses fuel power (especially when driving on steep roads such as off-road), the labyrinth baffle 13 can prevent liquid fuel from entering the intake manifold 200, thereby preventing the problem of gasoline burning in the intake manifold 200, which is beneficial for use with the intake manifold 200 made of plastic material, ensuring that the intake manifold 200 will not fail due to high combustion temperature; because the labyrinth baffle 13 blocks the liquid fuel and allows the liquid fuel to flow into the lower cavity 2, ensuring that the liquid fuel can flow back into the fuel tank 100 from the return oil port 21, blocking the faster-flowing fuel vapor, it has a certain silencing and energy-reducing effect, and can achieve the effect of reducing noise.

[0034] Furthermore, a plurality of groups of the labyrinth baffles 13 are sequentially arranged between the air inlet 11 and the air outlet 12 , wherein each group of the labyrinth baffles 13 blocks the oil and gas once.

[0035] Combination Figure 3 and Figure 5As shown, there are five groups of labyrinth baffles 13, which are the first baffle group 131, the second baffle group 132, the third baffle group 133, the fourth baffle group 134 and the fifth baffle group 135 from the air inlet 11 to the air outlet 12. Each group of labyrinth baffles 13 is provided with air holes. After the fuel vapor enters the upper cavity 1 from the air inlet 11, it passes through the first baffle group 131, the second baffle group 132, the third baffle group 133, the fourth baffle group 134 and the fifth baffle group 135 in sequence, and is finally transported from the air outlet 12 to the intake manifold 200, wherein most of the liquid and part of the gaseous fuel will form oil droplets on the labyrinth baffle 13 and fall into the lower cavity 2, so that it can flow back to the fuel tank 100 through the oil return port 21, and the remaining gaseous fuel will pass through the air holes on the labyrinth baffle 13 and finally smoothly enter the intake manifold 200.

[0036] In this way, multiple blockings by multiple groups of labyrinth baffles 13 can more efficiently block liquid and partially gaseous fuel and form oil droplets, thereby preventing liquid fuel from entering the intake manifold 200. Through the air holes on the labyrinth baffles 13, gaseous fuel can smoothly pass through and enter the intake manifold 200.

[0037] Furthermore, at least one group of the labyrinth baffles 13 is provided with a ventilation gap.

[0038] Combination Figure 3 and Figure 4 As shown, the first baffle group 131 and the third baffle group 133 in the labyrinth baffle 13 are not provided with air-permeable gaps. The first baffle group 131 is arranged around the air inlet 11 by three interconnected baffles, and the baffles on both sides are connected to the inner wall of the upper cavity 1 around the air inlet 11. The first baffle group 131 and the inner wall of the upper cavity 1 form a closed small cavity, so that the fuel vapor can only pass through the air holes on the first baffle group 131, so that the first baffle group 131 has a higher condensation efficiency; the third baffle group 133 is formed by five baffles connected to each other, and the entire third baffle group 133 continuously spans the upper cavity 1, and its two sides are connected to the inner wall of the upper cavity 1, dividing the upper cavity 1 into two, so that the fuel vapor can only pass through the air holes on the third baffle group 133, so that the third baffle group 133 has a higher condensation efficiency.

[0039] Combination Figure 4As shown, the air gap includes a first air gap 14 arranged on the second baffle group 132, a second air gap 15 arranged on the fourth baffle group 134 and a third air gap 16 arranged on the fifth baffle group 135. The size of the air gap is usually much larger than the air hole. The air gap is to ensure the flow of fuel vapor, while the air hole is to ensure the condensation effect on liquid fuel vapor. The second baffle group 132 is composed of three baffles, and a first air permeable gap 14 is provided between two adjacent baffles. The fuel vapor can pass through the air holes on the second baffle group 132 and the first air permeable gap 14, thereby improving the flow rate of the fuel vapor to a certain extent and ensuring that sufficient fuel vapor enters the intake manifold 200 to ensure the normal operation of the engine; the fourth baffle group 134 is composed of two baffles, and a second air permeable gap 15 is provided between the two baffles; and the fifth baffle group 135 is composed of one baffle, and a third air permeable gap 16 is provided between its two sides and the inner wall of the upper cavity 1, so that the fuel vapor can pass through the second air permeable gap 15 and the third air permeable gap 16, thereby ensuring that sufficient fuel vapor enters the intake manifold 200 through the air outlet 12 to ensure the normal operation of the engine.

[0040] Furthermore, the ventilation holes include a circular first hole 17 and a strip-shaped second hole 18 , and the first hole 17 and the second hole 18 are respectively disposed on two adjacent groups of the labyrinth baffles 13 .

[0041] Combination Figure 3 As shown, the first hole 17 is circular, and the first baffle group 131, the third baffle group 133 and the fifth baffle group 135 of the maze baffle 13 are each provided with a plurality of first holes 17 (the aperture of each first hole 17 may be equal or unequal), forming a mesh hole array, and the second hole 18 is strip-shaped (that is, one of the two sides of the rectangle is much longer than the other), and the second baffle group 132 and the fourth baffle group 134 are each provided with a plurality of second holes 18, forming a grid-like hole array.

[0042] In this way, two adjacent labyrinth baffles 13 (for example, the first baffle group 131 and the second baffle group 132 ) are respectively provided with air holes of different shapes, thereby improving the condensation efficiency of the labyrinth baffles 13 .

[0043] Furthermore, from the air inlet 11 to the air outlet 12, the inner diameters of the first holes 17 on the multiple groups of the labyrinth baffles 13 gradually decrease; from the air inlet 11 to the air outlet 12, the widths of the second holes 18 on the multiple groups of the labyrinth baffles 13 gradually decrease.

[0044] Combination Figure 3As shown, the first holes 17 are respectively distributed on the first baffle group 131, the third baffle group 133 and the fifth baffle group 135, and the specific values ​​of the inner diameters of the holes can be designed as needed, as long as the inner diameters of the holes can correspond to the order from the air inlet 11 to the air outlet 12 and gradually decrease; the second holes 18 are respectively distributed on the second baffle group 132 and the fourth baffle group 134, and the specific values ​​of the widths of the strip holes can be designed as needed, as long as the widths can correspond to the order from the air inlet 11 to the air outlet 12 and gradually decrease.

[0045] In this way, the air holes closer to the air outlet 12 have smaller sizes, which is beneficial to improving the condensation effect of the labyrinth baffle 13 .

[0046] Furthermore, it also includes a solenoid valve 3 , which is located between the air outlet 12 of the upper cavity 1 and the intake manifold 200 .

[0047] Combination Figure 2 and Figure 3 As shown, the fuel vapor enters the intake manifold 200 from the air outlet 12 through the solenoid valve 3 , and the opening and closing of the pipeline from the protection structure 300 to the intake manifold 200 can be controlled by the solenoid valve 3 .

[0048] Furthermore, a leakage plate 4 is provided between the upper cavity 1 and the lower cavity 2 , and a leakage hole 41 is provided on the leakage plate 4 , and the upper cavity 1 and the lower cavity 2 are communicated with each other through the leakage hole 41 .

[0049] Combination Figure 3 and Figure 5 As shown, the leakage plate 4 is installed between the upper cavity 1 and the lower cavity 2, and leakage holes 41 are provided on the leakage plate 4. The number, shape and size of the leakage holes 41 can be designed according to needs and are not limited here.

[0050] In this way, the oil droplets formed in the upper cavity 1 fall into the lower cavity 2 through the leakage holes 41 on the leakage plate 4, so that the oil droplets formed in the upper cavity 1 can be further collected and conveniently returned to the oil tank.

[0051] Furthermore, a one-way valve is provided at the oil return port 21 , a liquid baffle plate 22 is provided in the lower cavity 2 , the liquid baffle plate 22 separates the lower cavity 2 into a double-layer structure, and an oil passage port 221 is provided on the liquid baffle plate 22 .

[0052] Combination Figure 2 and Figure 5As shown, a one-way valve is provided at the oil return port 21, and a liquid baffle plate 22 (which can be a flat plate structure, or its shape and size can be designed as required) is provided in the lower cavity 2. The surrounding side walls of the liquid baffle plate 22 are connected to the inner wall of the lower cavity 2, thereby dividing the lower cavity 2 into a double-layer structure. The oil through port 221 can usually be set at the center of the liquid baffle plate 22 (its number, shape and size can be designed as required).

[0053] In this way, a one-way valve with corresponding parameters can be selected according to the maximum height of the oil to ensure that the one-way valve can be opened after the oil height in the lower cavity 2 reaches a certain threshold and smoothly return to the oil tank 100. In addition, the oil stored in the lower cavity 2 will shake as the vehicle travels, which may cause the oil to overflow into the upper cavity 1. The problem of the oil directly overflowing into the upper cavity 1 can be avoided by the liquid baffle 22.

[0054] Furthermore, the liquid baffle plate 22 is a funnel structure with a concave portion, and the oil passage port 221 is disposed at the concave portion of the funnel structure.

[0055] Combination Figure 5 and Figure 6 As shown, the liquid baffle plate 22 is a funnel structure, the central part of which is recessed downward to form a recessed portion, and the side parts thereof extend upward to be connected to the inner wall of the lower cavity 2, and four oil passage ports 221 are evenly spaced apart at the recessed portion of the funnel structure, so that the liquid fuel can flow along the recessed surface of the liquid baffle plate 22 to the oil passage ports 221, so that it can be ensured that the oil can smoothly enter the lower cavity 2 under the liquid baffle plate 22, and the oil can be prevented from overflowing due to the obstruction of the liquid baffle plate 22.

[0056] The utility model also provides an engine assembly, including the oil tank and the engine protection structure 300.

[0057] Combination Figure 1As shown, the engine assembly of the utility model includes the above-mentioned protective structure 300, whose air inlet 11 is connected to the fuel tank 100, so that gaseous and liquid fuel enters the upper cavity 1, and the liquid and part of the gaseous fuel contacts the labyrinth baffle 13 and cools to form oil droplets, and finally flows into the lower cavity 2, and the liquid fuel can be returned to the fuel tank 100 through the oil return port 21, and the remaining gaseous fuel finally enters the intake manifold 200 from the air outlet 12 through the air vent. The utility model is particularly suitable for hybrid vehicles. When the user drives the fuel tank 100 for a long time, the fuel vapor generated by the fuel vapor is too much, and the labyrinth baffle 13 of the protective structure 300 can prevent the fuel vapor from forming. The oil drops are formed and flow back to the fuel tank 100, thereby preventing the fuel tank 100 from being damaged by overpressure. When the user uses fuel power, the labyrinth baffle 13 can prevent liquid fuel from entering the intake manifold 200, thereby preventing the problem of gasoline burning in the intake manifold 200, which is beneficial for use with the intake manifold 200 made of plastic material, thereby ensuring that the intake manifold 200 will not fail due to high combustion temperature. Since the labyrinth baffle 13 blocks the liquid fuel and allows the liquid fuel to flow into the lower cavity 2, it is ensured that the liquid fuel can flow back to the fuel tank 100 from the oil return port 21, thereby blocking the fuel vapor with a faster flow rate, having a certain silencing and energy reduction effect, and can achieve the effect of reducing noise.

[0058] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0059] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, rotated 90 degrees or in other orientations, and the spatially relative descriptions used herein are interpreted accordingly.

[0060] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present utility model.

[0061] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0062] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A protective structure for a fuel tank and an engine, characterized in that: It includes an upper cavity and a lower cavity, the air inlet of the upper cavity is connected to the fuel tank, the air outlet of the upper cavity is connected to the intake manifold of the engine, a labyrinth baffle is provided in the upper cavity, the labyrinth baffle is located between the air inlet and the air outlet, and air holes are provided on the labyrinth baffle, the lower cavity is communicated with the upper cavity, and the oil return port of the lower cavity is connected to the fuel tank.

2. The protective structure of the fuel tank and the engine according to claim 1, characterized in that: A plurality of groups of the labyrinth baffles are sequentially arranged between the air inlet and the air outlet, wherein each group of the labyrinth baffles blocks the oil and gas once.

3. The protective structure of the fuel tank and the engine according to claim 2, characterized in that: At least one group of the labyrinth baffles is provided with a ventilation gap.

4. The protective structure of the fuel tank and the engine according to claim 2, characterized in that: The ventilation holes include a first circular hole and a second strip-shaped hole, and the first hole and the second hole are respectively arranged on two adjacent groups of the maze baffles.

5. The protective structure of the fuel tank and the engine according to claim 4, characterized in that: From the air inlet to the air outlet, the inner diameters of the first holes on the multiple groups of the labyrinth baffles gradually decrease; from the air inlet to the air outlet, the widths of the second holes on the multiple groups of the labyrinth baffles gradually decrease.

6. The protective structure of the fuel tank and the engine according to claim 1, characterized in that: It also includes a solenoid valve, which is located between the air outlet of the upper cavity and the intake manifold.

7. The protective structure of the fuel tank and the engine according to claim 1, characterized in that: A leakage plate is provided between the upper cavity and the lower cavity, and a leakage hole is provided on the leakage plate. The upper cavity is communicated with the lower cavity through the leakage hole.

8. The protective structure of the fuel tank and the engine according to claim 1, characterized in that: A one-way valve is provided at the oil return port, a liquid baffle is provided in the lower cavity, the liquid baffle divides the lower cavity into a double-layer structure, and an oil passage port is provided on the liquid baffle.

9. The protective structure of the fuel tank and the engine according to claim 8, characterized in that: The liquid baffle plate is a funnel structure with a concave portion, and the oil passage port is arranged at the concave portion of the funnel structure.

10. An engine assembly, characterized in that: A protective structure comprising a fuel tank and an engine as claimed in any one of claims 1 to 9.

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