An oil filler cap

Abstract

The application discloses a machine oil filler cap, which comprises a cover, a sealing seat and an elastic member. The cover is used to cover the filler of an object and is detachably installed on the object. The cover has a cavity, a pressure relief channel and a connecting channel. The pressure relief channel is connected with the cavity and the inner cavity of the object. The connecting channel is connected with the outside and the cavity. The sealing seat is movably arranged in the cavity. In the movement stroke, the sealing seat has a sealing position for blocking the pressure relief channel and a conducting position for conducting the pressure relief channel and the connecting channel. The sealing seat can move from the sealing position to the conducting position when driven by the fluid output by the pressure relief channel. The elastic member connects the sealing seat and the cover, and drives the sealing seat to switch from the conducting position to the sealing position. When the crankcase pressure reaches the early warning value, the machine oil filler cap can open the sealing seat to release the pressure, effectively preventing the damage caused by the excessive crankcase pressure, and protecting the engine from being damaged.

Description

Technical Field

[0001] This invention relates to the technical field of crankcase oil filler caps, and specifically to an oil filler cap. Background Technology

[0002] The oil filler cap serves as both an oil filling channel and a connection to the crankcase. Current engine oil filler caps are generally arranged in two ways: side-mounted and top-mounted. The side-mounted type is located on the side of the engine and is a dedicated filler cap, directly adding oil to the oil pan in the crankcase. The top-mounted type is located on the top of the engine, and after the oil is filled, it flows through the cylinder head oil hole into the oil pan in the crankcase.

[0003] Publication number CN202250299U discloses an engine oil filling device, which includes an oil filling connection pipe fixedly installed on the oil pan. The oil filling connection pipe is a bent pipe with the open end facing upwards, and the open end is connected to a filler connector, which is equipped with an oil filling cap. The part of the oil filling connection pipe that connects to the oil pan is located on the upper surface of the oil pan. The oil filling pipe can extend from the side of the cab, allowing people to add oil directly while standing on the side of the commercial vehicle, improving convenience.

[0004] However, regardless of the arrangement, because the crankcase of a closed-ventilation engine is not connected to the outside, the gas returns directly to the engine intake. Furthermore, the sealed oil filler cap also isolates the crankcase from the outside environment. When the engine has difficulty starting or experiences minor cylinder scoring, a significant amount of combustible mixture can flow down from the combustion chamber into the crankcase, causing excessive crankcase pressure and adversely affecting the crankcase. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an oil filler cap to solve the technical problem in the prior art where the crankcase of a closed-ventilation engine is not connected to the outside world, and the gas directly returns to the engine air intake. The sealing of the oil filler cap also isolates the crankcase from the outside world, which can easily lead to excessive crankcase pressure and have an adverse effect on the crankcase.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] This invention provides an oil filler cap, comprising:

[0008] A cap for covering the filling port of an object and detachably installed on the object, having a cavity, a pressure relief channel and a connecting channel, wherein the pressure relief channel connects the cavity to the inner cavity of the object, and the connecting channel connects the outside to the cavity;

[0009] A sealing seat, movably disposed within the cavity, has a sealing position that blocks the pressure relief channel during its movement, and a conducting position that connects the pressure relief channel to the connecting channel. Furthermore, when driven by the fluid output from the pressure relief channel, it can move from the sealing position to the conducting position.

[0010] An elastic element connects the sealing seat and the cover, thereby driving the sealing seat to switch from the open position to the sealed position.

[0011] In some embodiments, the sealing seat is located between the pressure relief channel and the connecting channel, and is movable along the arrangement direction of the pressure relief channel and the connecting channel, and isolates the cavity along its movable direction, and is provided with a flow passage;

[0012] The flow passage is offset from the pressure relief passage when the sealing seat is in the sealing position, and connects the pressure relief passage and the connection passage when the sealing seat is in the conducting position.

[0013] In some embodiments, the elastic element includes a compression spring, one end of which is connected to the sealing seat and the other end is connected to the inner wall of the cavity, and is located on the side of the sealing seat away from the pressure relief channel.

[0014] In some embodiments, the sealing seat has a mounting cavity on the side near the connection channel;

[0015] The flow channel connects to the mounting cavity. One end of the compression spring is located inside the mounting cavity, and the other end is connected to the inner wall of the cavity and located on the side of the cavity away from the pressure relief channel.

[0016] In some embodiments, the elastic element further includes an adjusting seat and a driving part. The adjusting seat is disposed in the cavity and located on the side of the sealing seat away from the pressure relief channel, and is movable in the direction of approaching and away from the pressure relief channel. The driving part is drivenly connected to the adjusting seat and is used to drive the adjusting seat to move.

[0017] The compression spring connects the adjusting seat and the sealing seat.

[0018] In some embodiments, the cover is provided with an adjustment screw hole in a direction away from the adjustment seat, and the adjustment screw hole is located on the side of the sealing seat away from the pressure relief channel;

[0019] The driving unit includes a dial and a driving screw. The dial is located outside the cover, and its inner ring is connected to the adjusting screw hole. It is provided with scale lines along its circumference. One end of the driving screw passes through the inner ring of the dial, is screwed into the adjusting screw hole, and is connected to the adjusting seat.

[0020] In some embodiments, the adjusting seat has a fixing groove on the side near the sealing seat, and the end of the compression spring near the adjusting seat is located in the fixing groove.

[0021] In some embodiments, the sealing seat includes, in sequence, an isolation section, a straight section, and a tapered section along the direction close to the pressure relief channel. The isolation section divides the cavity along its direction of movement. The outer diameter of the straight section is smaller than the outer diameter of the isolation section. The tapered section is gradually tapered along the direction close to the pressure relief channel.

[0022] The inner wall of the cavity is provided with a conical groove corresponding to the conical section. The pressure relief channel is located at the bottom of the conical groove, and the flow passage is located on the side wall of the straight section and connects the two sides of the cavity in the direction of movement of the isolation section.

[0023] In some embodiments, the oil filler cap further includes an oil baffle seat, which is connected to the cap and located on the side of the cap where the pressure relief channel is provided. An oil baffle cavity is formed between the oil baffle seat and the cap, and a through hole is provided that communicates with the oil baffle cavity. The through hole is offset from the pressure relief channel.

[0024] In some embodiments, the connecting channel includes a first segment, a buffer segment, and a second segment connected sequentially in a direction away from the cavity, wherein the cross-sectional area of ​​the buffer segment is larger than the cross-sectional areas of the first segment and the second segment; and / or,

[0025] The periphery of the cap is provided with a connecting ring facing the object, and the connecting ring is provided with an internal thread for screwing onto the external thread end edge of the filling port.

[0026] Compared with existing technologies, the oil filler cap provided by this invention is installed at the engine filler cap position after the oil has been filled. When the engine is working normally, the sealing seat is in the blocking position under the preload of the elastic element, blocking the pressure relief passage and closing the passage between the crankcase gas and the external environment. However, when the engine experiences abnormal conditions such as difficulty starting, or when there is significant wear in the cylinder after long-term use, the amount of gas entering the crankcase from the combustion chamber increases, causing the pressure inside the crankcase to increase. When the pressure exceeds a set value, it can overcome the preload of the elastic element and push the sealing seat to the open position, allowing the gas in the crankcase to rise from the pressure relief passage and then be discharged from the connecting passage, opening the crankcase to the external environment and releasing pressure. After venting, the pressure inside the crankcase drops to a normal level. At this time, the elastic element pushes the sealing seat back into place, reforming the seal and isolating the crankcase from the external environment again. Thus, this solution ensures that when the crankcase pressure reaches the warning value, the oil filler cap can open the sealing seat to release pressure, effectively preventing damage caused by excessive crankcase pressure and protecting the engine from damage. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the oil filler cap provided in an embodiment of the present invention;

[0028] Figure 2 yes Figure 1 Partial sectional view of the oil filler cap;

[0029] Figure 3 yes Figure 1 Another partial sectional view of the oil filler cap;

[0030] Figure 4 yes Figure 1 A partial cross-sectional view of the middle cover with a pressure relief channel;

[0031] Figure 5 yes Figure 4 A top view of the portion of the central cover that has a pressure relief channel;

[0032] Figure 6 yes Figure 1 Top view of the middle oil stop.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Cover; 1a. Cavity; 1b. Pressure relief channel; 1c. Connecting channel; 1c1. First section; 1c2. Buffer section; 1c3. Second section; 1d. Conical groove; 11. Connecting ring; 2. Sealing seat; 2a. Flow channel; 2b. Mounting cavity; 21. Isolation section; 22. Straight section; 23. Conical section; 3. Elastic element; 31. Compression spring; 32. Adjusting seat; 33. Drive unit; 331. Dial; 332. Drive screw; 4. Oil baffle seat; 4a. Oil baffle cavity; 4b. Through hole. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0036] To address the technical problem in existing technologies where the crankcase of a closed-ventilation engine is not connected to the outside environment, allowing gas to return directly to the engine intake, and the oil filler cap also isolates the crankcase from the outside, leading to excessive crankcase pressure and adverse effects on the crankcase, this invention provides an oil filler cap that can open its sealing seat to release pressure when the crankcase pressure reaches a warning value. This effectively prevents damage to the engine caused by excessive crankcase pressure and protects the engine from damage.

[0037] It should be noted that the oil filler cap described in this invention is used in, but not limited to, engine crankcases, etc. For ease of explanation, this invention only uses the application of the oil filler cap to the engine crankcase as an example. The principle of the oil filler cap in other types of equipment is essentially the same as that in the engine crankcase, and will not be described in detail here.

[0038] Please see Figure 1 and Figure 2 , Figure 1 and Figure 2 This is a schematic diagram of the structure of an oil filler cap according to an embodiment of the present invention. The oil filler cap includes a cap 1, a sealing seat 2, and an elastic element 3. The cap 1 is used to cover the filler port of an object and is detachably installed on the object. It has a cavity 1a, a pressure relief channel 1b, and a connecting channel 1c. The pressure relief channel 1b connects the cavity 1a with the inner cavity of the object, and the connecting channel 1c connects the outside with the cavity 1a. The sealing seat 2 is movably disposed in the cavity 1a. During its movement, it has a sealing position that blocks the pressure relief channel 1b and a connecting position that connects the pressure relief channel 1b and the connecting channel 1c. When driven by the fluid output from the pressure relief channel 1b, it can move from the sealing position to the connecting position. The elastic element 3 connects the sealing seat 2 and the cap 1 to drive the sealing seat 2 to switch from the connecting position to the sealing position.

[0039] In the oil filler cap provided by this invention, after the oil is filled, the cap 1 is installed at the filler port of the engine. When the engine is working normally, the sealing seat 2 is in the blocking position under the pre-tightening force of the elastic element 3, blocking the pressure relief channel 1b and closing the passage between the crankcase gas and the external environment. However, when the engine experiences abnormal conditions such as difficulty starting, or when there is significant wear in the cylinder after long-term use, the amount of gas entering the crankcase from the combustion chamber increases, causing the pressure inside the crankcase to increase. When the pressure exceeds a set value, it can overcome the pre-tightening force of the elastic element 3 and push the sealing seat 2 to switch to the open position, allowing the gas in the crankcase to rise from the pressure relief channel 1b and then be discharged from the connecting channel 1c, allowing the crankcase to communicate with the external environment and release pressure and exhaust gas. After exhausting, the pressure inside the crankcase drops to a normal level. At this time, the elastic element 3 pushes the sealing seat 2 back into place, re-forming a seal and isolating the crankcase from the external environment again. Thus, this solution ensures that when the crankcase pressure reaches the warning value, the oil filler cap can open the sealing seat 2 to release pressure, effectively preventing damage caused by excessive crankcase pressure and protecting the engine from damage.

[0040] It should be understood that the safety valve type oil filler cap of this invention, through the integrated safety valve type sealing seat 2, achieves controllable crankcase pressure relief, ensuring engine safety and effectively preventing damage to the engine caused by excessive crankcase pressure. It is suitable for commercial vehicle engines, especially gas engines. Specifically, it achieves the following effects: safe pressure relief, avoiding problems such as oil seal failure, insufficient lubrication wear, crankcase system failure, and reduced engine power caused by excessive crankcase pressure; preventing deformation and cracking of the non-metallic oil pan caused by excessive crankcase pressure; and preventing safety accidents caused by non-metallic oil pan rupture due to crankcase deflagration in gas engines.

[0041] In one embodiment, the sealing seat 2 is located between the pressure relief channel 1b and the connecting channel 1c, and can move along the arrangement direction of the pressure relief channel 1b and the connecting channel 1c, and isolate the cavity 1a along its moving direction, and is provided with a flow passage 2a; wherein, when the sealing seat 2 is in the sealing position, the flow passage 2a is offset from the pressure relief channel 1b, and when the sealing seat 2 is in the conducting position, it connects the pressure relief channel 1b and the connecting channel 1c.

[0042] In this embodiment, the pressure relief channel 1b and the connecting channel 1c are placed on both sides of the sealing seat 2, and the flow passage 2a is staggered from the pressure relief channel 1b, so that when the oil accidentally escapes from the pressure relief channel 1b, it can first collide with the sealing seat 2 and be deflected, thus preventing the oil from being discharged directly from the connecting channel 1c.

[0043] In one embodiment, the elastic element 3 includes a compression spring 31, one end of which is connected to the sealing seat 2 and the other end is connected to the inner wall of the cavity 1a, and is located on the side of the sealing seat 2 away from the pressure relief channel 1b.

[0044] In this embodiment, the elastic element 3 is configured as a compression spring 31. The elastic force of the compression spring 31 ensures that the sealing seat 2 can be stably positioned in the sealing position after pressure relief, resulting in a simple and reliable structure. Furthermore, the compression spring 31 is positioned on the side of the sealing seat 2 away from the pressure relief channel 1b, reducing the probability of the compression spring 31 contacting the oil and extending its service life. It should be noted that the structure of the elastic element 3 is not limited, as long as it allows the sealing seat 2 to return to the sealing position and can be overcome by the high-pressure airflow. In one embodiment, the elastic element 3 is configured as a spring sheet; in another embodiment, the elastic element 3 is configured as a torsion spring.

[0045] In one embodiment, the sealing seat 2 has an installation cavity 2b on the side near the connecting channel 1c; the flow channel 2a connects to the installation cavity 2b, one end of the compression spring 31 is located in the installation cavity 2b, and the other end is connected to the inner wall of the cavity 1a and located on the side of the cavity 1a away from the pressure relief channel 1b.

[0046] In this embodiment, an installation cavity 2b for placing the compression spring 31 is provided on the sealing seat 2, making the overall structure more compact and saving the space occupied by the oil filler cap.

[0047] In one embodiment, the elastic element 3 further includes an adjusting seat 32 and a driving part 33. The adjusting seat 32 is disposed in the cavity 1a and located on the side of the sealing seat 2 away from the pressure relief channel 1b, and can move in the direction of approaching and away from the pressure relief channel 1b. The driving part 33 is drivenly connected to the adjusting seat 32 and is used to drive the adjusting seat 32 to move. The compression spring 31 connects the adjusting seat 32 and the sealing seat 2.

[0048] In this embodiment, the distance between the adjustment seat 32 and the sealing seat 2 when they are in the blocking position can be adjusted as needed, thereby flexibly adjusting and locking the preload of the compression spring 31, so as to make adjustments according to the needs of different models and altitudes, improving practicality and flexibility.

[0049] It should be noted that the configuration of the drive unit 33 is not limited, as long as it can stably drive the adjustment plate to move closer to and further away from the pressure relief channel 1b. In one embodiment, the adjustment unit is configured as a linear motor; while in another embodiment, the drive unit 33 is configured as a hydraulic cylinder.

[0050] In one embodiment, please refer to Figure 3 The cover 1 is provided with an adjustment screw hole in the direction away from the adjustment seat 32. The adjustment screw hole is located on the side of the sealing seat 2 away from the pressure relief channel 1b. The drive unit 33 includes a dial 331 and a drive screw 332. The dial 331 is located outside the cover 1, and its inner ring is connected to the adjustment screw hole. It is provided with scale lines along its circumference. One end of the drive screw 332 passes through the inner ring of the dial 331 and is screwed into the adjustment screw hole and connected to the adjustment seat 32.

[0051] In this embodiment, the drive unit 33 is configured as a drive screw 332. By rotating the drive screw 332, its depth into the filler neck is adjusted, thereby adjusting the distance between the adjustment plate and the pressure relief channel 1b. The structure is simple and reliable. At the same time, a dial 331 is provided corresponding to the drive screw 332 to accurately display the pressure relief warning value, improving convenience.

[0052] In one embodiment, the adjusting seat 32 is provided with a fixing groove on the side near the sealing seat 2, and the end of the compression spring 31 near the adjusting seat 32 is located in the fixing groove.

[0053] In this embodiment, the compression spring 31 is placed in the fixing groove and the mounting cavity 2b. The side walls of the fixing groove and the mounting cavity 2b are used for limiting and guiding, ensuring the stable movement of the compression spring 31 and improving the ease of assembly.

[0054] In one embodiment, please refer to Figure 2 and Figure 4 The sealing seat 2 includes, in sequence, an isolation section 21, a straight section 22, and a conical section 23 along the direction close to the pressure relief channel 1b. The isolation section 21 divides the cavity 1a along its direction of movement. The outer diameter of the straight section 22 is smaller than the outer diameter of the isolation section 21. The conical section 23 is gradually tapered along the direction close to the pressure relief channel 1b. The inner wall of the cavity 1a is provided with a conical groove 1d corresponding to the conical section 23. The pressure relief channel 1b is located at the bottom of the conical groove 1d. The flow passage 2a is located on the side wall of the straight section 22 and connects the two sides of the cavity 1a in the direction of movement of the isolation section 21.

[0055] In this embodiment, the flow passage 2a is located on the straight section 22, while the pressure relief passage 1b is placed at the bottom of the conical groove 1d. Thus, when the sealing seat 2 is in the blocking position, the conical section 23 of the sealing seat 2 can be placed in the conical groove 1d, completely isolating the pressure relief passage 1b. Furthermore, the pressure relief passage 1b and the flow passage 2a are not located on the same plane, improving sealing capability and ensuring that the crankcase is not connected to the outside. When pressure is released, the air pressure pushes the conical section 23 of the sealing seat 2 upwards, and as it passes through the pressure relief passage 1b, it first collides with the conical section 23, causing the oil in the airflow to be deflected. The gas then exits from the flow passage 2a on the side wall of the straight section 22, further reducing oil consumption.

[0056] In one embodiment, please refer to Figures 4 to 6 The oil filler cap also includes an oil baffle 4, which is connected to the cover 1 and located on the side of the cover 1 where the pressure relief channel 1b is provided. An oil baffle cavity 4a is formed between the cover 1 and the cover 1, and a through hole 4b is provided to connect the oil baffle cavity 4a. The through hole 4b is offset from the pressure relief channel 1b.

[0057] In this embodiment, an oil baffle 4 is also provided on the side of the cover 1 where the pressure relief channel 1b is provided, and the through hole 4b of the oil baffle 4 is spaced apart from the pressure relief channel 1b to further prevent engine oil from splashing to the outside through the pressure relief channel 1b. It should be noted that in this embodiment, multiple pressure relief channels 1b and through holes 4b are provided, and each through hole 4b is staggered from the pressure relief channel 1b.

[0058] In one embodiment, the connecting channel 1c includes a first segment 1c1, a buffer segment 1c2 and a second segment 1c3 connected in sequence along the direction away from the cavity 1a, wherein the cross-sectional area of ​​the buffer segment 1c2 is larger than the cross-sectional areas of the first segment 1c1 and the second segment 1c3.

[0059] In this embodiment, the connecting channel 1c is also configured as above to form a buffer section 1c2, which reduces local resistance and accelerates the gas exhaust rate.

[0060] It should be noted that the connection method between the cover 1 and the engine is not limited, as long as a detachable connection can be achieved and the oil filler port is sealed. In one embodiment, the cover 1 and the engine filler port are detachably connected by bolts; in another embodiment, the cover 1 and the engine filler port are detachably connected by clips.

[0061] In one embodiment, the periphery of the cap 1 is provided with a connecting ring 11 facing the object. The connecting ring 11 is provided with an internal thread for screwing onto the external thread end edge of the filling port.

[0062] In this embodiment, a connecting ring 11 with internal threads is provided on the cover 1, and an end edge with external threads is provided at the filling port of the engine. The detachable connection is achieved through threaded engagement, which is simple and reliable in structure and convenient in operation.

[0063] To better understand this invention, the following is combined with... Figures 1 to 6 The technical solution of the present invention will be described in detail below:

[0064] The specific working principle is as follows:

[0065] When the engine is in normal operating condition, the compression spring 31 pushes the sealing seat 2 to contact the inner wall of the conical groove 1d of the cavity 1a under the action of preload. The conical section 23 of the sealing seat 2 and the conical groove 1d of the cavity 1a form a conical seal, closing the crankcase gas passage.

[0066] When an engine experiences starting difficulties requiring continuous ignition or when cylinder liner-piston ring wear is significant after prolonged operation, combustion chamber gases surge downwards, increasing crankcase pressure. When this pressure exceeds a set value, the crankcase pressure pushes the sealing seat 2 upwards, compressing the compression spring 31 and causing the sealing seat 2 to rise away from the conical groove 1d. At this point, the crankcase is connected to the external environment, and the internal gases rise, flowing sequentially through the pressure relief channel 1b, the flow channel 2a, and the connecting channel 1c, finally releasing the pressure and returning the crankcase pressure to normal levels. After pressure relief and exhaust, the crankcase pressure decreases, and the spring pushes the sealing seat 2 downwards, reforming the seal and isolating the crankcase from the external environment.

[0067] Furthermore, this solution allows for adjustment and locking of the preload of the compression spring 31 via the dial 331 and drive screw 332, based on the requirements of different engine models and altitude variations. The oil baffle 4, with its perforated structure, prevents oil from splashing onto the outside while releasing pressure and venting gas. This technical solution ensures that when the crankcase pressure reaches the warning value (set value), the oil filler cap can open the sealing seat 2 to release pressure, protecting the engine from damage.

[0068] Therefore, compared with existing technical solutions, the solution of this patent has the following objective advantages:

[0069] 1) The existing oil filler cap is a simple sealing cap 1, while the patented solution is an integrated safety pressure relief valve cap, which is fundamentally different in structure;

[0070] 2) Existing solutions are all closed systems without ventilation, while this solution has both controllable closed and ventilation functions.

[0071] 3) Existing solutions cannot solve the problem of excessive crankcase pressure. This solution can safely release pressure when it is too high, ensuring engine safety.

[0072] 4) The design of the dial 331 on the top of the filling port cap and the drive screw 332 makes the device suitable for different models and different altitudes.

[0073] 5) The orifice plate structure of this design ensures that the oil will not splash to the outside when the pressure is released.

[0074] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An oil filler cap, characterized in that, include: A cap for covering the filling port of an object and detachably installed on the object, having a cavity, a pressure relief channel and a connecting channel, wherein the pressure relief channel connects the cavity to the inner cavity of the object, and the connecting channel connects the outside to the cavity; A sealing seat, movably disposed within the cavity, has a sealing position that blocks the pressure relief channel during its movement, and a conducting position that connects the pressure relief channel to the connecting channel. Furthermore, when driven by the fluid output from the pressure relief channel, it can move from the sealing position to the conducting position. An elastic element connects the sealing seat and the cover to drive the sealing seat to switch from the open position to the sealed position; The sealing seat includes, in sequence, an isolation section, a straight section, and a conical section along the direction close to the pressure relief channel. The isolation section divides the cavity along its direction of movement. The outer diameter of the straight section is smaller than the outer diameter of the isolation section. The conical section is tapered along the direction close to the pressure relief channel. The inner wall of the cavity is provided with a conical groove corresponding to the conical section, and the pressure relief channel is located at the bottom of the conical groove.

2. The oil filler cap according to claim 1, characterized in that, The sealing seat is located between the pressure relief channel and the connecting channel, and can move along the arrangement direction of the pressure relief channel and the connecting channel, and isolates the cavity along its moving direction, and is provided with a flow channel; The flow passage is offset from the pressure relief passage when the sealing seat is in the sealing position, and connects the pressure relief passage and the connection passage when the sealing seat is in the conducting position.

3. The oil filler cap according to claim 2, characterized in that, The elastic element includes a compression spring, one end of which is connected to the sealing seat and the other end is connected to the inner wall of the cavity, and is located on the side of the sealing seat away from the pressure relief channel.

4. The oil filler cap according to claim 3, characterized in that, The sealing seat has a mounting cavity on the side near the connection channel; The flow channel connects to the mounting cavity. One end of the compression spring is located inside the mounting cavity, and the other end is connected to the inner wall of the cavity and located on the side of the cavity away from the pressure relief channel.

5. The oil filler cap according to claim 3, characterized in that, The elastic element further includes an adjusting seat and a driving part. The adjusting seat is disposed in the cavity and located on the side of the sealing seat away from the pressure relief channel, and can move in the direction of approaching and away from the pressure relief channel. The driving part is drivenly connected to the adjusting seat and is used to drive the adjusting seat to move. The compression spring connects the adjusting seat and the sealing seat.

6. The oil filler cap according to claim 5, characterized in that, The cover is provided with an adjustment screw hole in a direction away from the adjustment seat, and the adjustment screw hole is located on the side of the sealing seat away from the pressure relief channel; The driving unit includes a dial and a driving screw. The dial is located outside the cover, and its inner ring is connected to the adjusting screw hole. It is provided with scale lines along its circumference. One end of the driving screw passes through the inner ring of the dial, is screwed into the adjusting screw hole, and is connected to the adjusting seat.

7. The oil filler cap according to claim 5, characterized in that, The adjusting seat has a fixing groove on the side near the sealing seat, and the end of the compression spring near the adjusting seat is located in the fixing groove.

8. The oil filler cap according to claim 2, characterized in that, The flow channel is located on the side wall of the straight section and connects the cavity on both sides of the isolation section in the direction of movement.

9. The oil filler cap according to claim 1, characterized in that, The oil filler cap also includes an oil baffle seat, which is connected to the cover and located on the side of the cover where the pressure relief channel is provided. An oil baffle cavity is formed between the oil baffle seat and the cover, and a through hole is provided that communicates with the oil baffle cavity. The through hole is offset from the pressure relief channel.

10. The oil filler cap according to claim 1, characterized in that, The connecting channel, along a direction away from the cavity, includes a first segment, a buffer segment, and a second segment connected in sequence, wherein the cross-sectional area of ​​the buffer segment is larger than the cross-sectional areas of the first segment and the second segment; and / or, The periphery of the cap is provided with a connecting ring facing the object, and the connecting ring is provided with an internal thread for screwing onto the external thread end edge of the filling port.

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