Engine valve mechanism and valve mechanism thereof

Abstract

The invention discloses an engine valve mechanism and an air distribution mechanism thereof, and relates to the technical field of engine parts, and the engine valve mechanism comprises a cam and a driving shaft; the cam comprises a cam body, a first sliding part, a second sliding part, a first connecting rod, a second connecting rod and a storage cavity. The wheel body main body is connected with the second sliding part, the second sliding part is connected with the first sliding part, the second sliding part, the wheel body main body and the first sliding part form a cam, a storage cavity and a first containing space communicated with the storage cavity are formed in the wheel body main body, one end of the second connecting rod is embedded in the first containing space, and the other end of the second connecting rod is connected with the second sliding part; the second connecting rod and the second sliding part are jointly provided with a second containing space, one end of the first connecting rod is embedded in the storage cavity, and the other end of the first connecting rod is connected with the first sliding part. The defects that an existing variable valve lift mechanism is too complex in structure and high in cost are overcome.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine components, and particularly relates to an engine valve mechanism and its valve train mechanism. Background Art

[0002] In an automotive engine, the combustion chamber exchanges with external air and combustion exhaust gas through intake valves and exhaust valves. The intake valves are responsible for supplying fresh air or mixture, while the exhaust valves discharge the combustion exhaust gas. In traditional engine designs, the opening / closing times and lift of the intake and exhaust valves are fixed and cannot be adjusted according to different operating conditions.

[0003] However, under different engine speeds and load conditions, the optimal valve opening and closing times and lift are not the same. For example, when the engine is running at low speed and light load, due to the small inertia of the air flow, a smaller valve lift is more conducive to the formation of intake swirl; while at high speed, in order to increase the power output of the engine, a larger valve lift is more conducive to increasing the intake air volume. Therefore, the traditional fixed valve lift mechanism cannot always maintain the optimal valve train state under different operating conditions and usually requires a compromise between performance and fuel consumption.

[0004] To address this challenge, variable valve lift technology has emerged. This technology adjusts the valve lift through an electronic control system, sensors, and mechanical structures, enabling the engine to achieve the best intake effect under different operating conditions. However, the current variable valve lift technology has a relatively complex structure and high cost, so it is not easily widely accepted by ordinary consumers.

[0005] Therefore, an engine valve mechanism and its valve train mechanism are needed. Summary of the Invention

[0006] The purpose of the present invention is to provide an engine valve mechanism and its valve train mechanism, thereby overcoming the defects of the existing variable valve lift mechanism being too complex in structure and high in cost. The specific technical solutions are as follows:

[0007] On the one hand, an engine valve mechanism is provided. The engine valve mechanism includes a cam and a drive shaft; the drive shaft is connected to the output main shaft in the engine so that the rotational speed of the drive shaft is in a direct proportional relationship with the rotational speed of the output main shaft;

[0008] The cam includes a wheel body main body, a first sliding part, a second sliding part, a first connecting rod, a second connecting rod and a storage cavity; the wheel body main body is connected to the second sliding part, the second sliding part is connected to the first sliding part, and the cam is formed with the wheel body main body and the first sliding part. A storage cavity and a first accommodation space communicating with the storage cavity are arranged in the wheel body main body. One end of the second connecting rod is fitted in the first accommodation space, and the other end is connected to the second sliding part. A second accommodation space is jointly arranged on the second connecting rod and the second sliding part. One end of the first connecting rod is fitted in the storage cavity, and the other end is connected to the first sliding part;

[0009] The wheel body main body is connected to the drive shaft, and a fluid medium is arranged in the storage cavity; when the drive shaft rotates, the first connecting rod moves into the first accommodation space, seals the second accommodation space, and makes the first accommodation space communicate with the storage cavity;

[0010] A first limiting mechanism is arranged on the first connecting rod to limit the sliding stroke of the first connecting rod in the second accommodation space, and a second limiting mechanism is arranged on the second connecting rod to limit the sliding stroke of the second connecting rod in the first accommodation space.

[0011] Among them, in the case of high speed, the output main shaft requires more power. In this case, the rotational speed of the drive shaft increases. The present invention adjusts the structural length of the cam by using the rotational speed difference between the high speed and the low speed of the drive shaft to adjust the control of the stroke of the cam on the valve. Among them, the cam is divided into a wheel body main body, a first sliding part and a second sliding part. During the low-speed rotation of the cam, the stroke of the cam pushing the valve is small to match the intake requirement of the engine. When the engine speed increases, the rotational speed of the drive shaft increases accordingly, so that the rotational speed of the cam increases. At this time, the second sliding part gradually slides outwards from the cam body as the rotational speed increases, making the overall structure of the cam gradually grow. Therefore, when the cam contacts the valve, the valve stroke can be increased, allowing more gas to enter the engine cylinder. During this process, when the second sliding part moves, the second connecting rod pumps out the fluid medium in the storage cavity, and before the cam contacts the valve, the storage cavity is sealed by the first connecting rod of the first sliding part, so that the second sliding part can be fixed, enabling the deformation amount of the cam to be accurately transmitted to the valve.

[0012] Preferably, the valve includes a valve tappet, a valve stem, and a contact block. The lower end surface of the valve tappet is connected to the valve stem, and the contact block is installed on the upper end surface. The contact block is located on one side of the upper end surface of the valve tappet. The contact block has an inclined surface tangent to the first sliding portion, so that before the first sliding portion contacts the valve tappet, the first connecting rod is moved into the storage cavity through the contact block, and the storage cavity is sealed.

[0013] Among them, when the cam rotates at a high speed, the first connecting rod and the first sliding block are advanced to move towards the main body of the wheel through the contact block, disconnecting the connection between the first accommodation space and the storage cavity, thereby fixing the second sliding portion. Ensure that during the time of contact with the valve, the length of the cam structure remains unchanged, so as to feedback the self-adaptive length change of the cam to the output main shaft to the valve.

[0014] Preferably, the first limiting mechanism includes a receiving hole, a sealing member, and a dredging groove; a receiving hole is provided at one end of the second connecting rod, a sealing member is provided at one end of the first connecting rod, a dredging groove is provided on the inner wall of the receiving hole, and the sealing member is fitted with the receiving hole to seal the second accommodation space.

[0015] Among them, the first connecting rod is limited by being fitted into the receiving hole through the sealing member to ensure that the first connecting rod will not be thrown out of the main body of the wheel. The dredging groove on the inner wall of the receiving hole can make the volume of the bottom surface of the second connecting rod and the first accommodation space remain unchanged even when the first connecting rod moves when the second connecting rod withdraws the fluid medium, so as to ensure that the amount of the second sliding portion extending out of the main body of the wheel matches the rotational speed.

[0016] Preferably, the second limiting mechanism includes a first limiting groove, a clamping block, and a first spring; the main body of the wheel is provided with the first limiting groove, the first limiting groove communicates with the first accommodation space, the second connecting rod is provided with the clamping block that is mutually fitted with the first limiting groove, and the first spring is provided in the first limiting groove. When the cam reaches the first preset speed, the second connecting rod moves out of the first accommodation space against the elastic force of the first spring.

[0017] Preferably, the second sliding portion is provided with a second limiting groove, and a second spring is provided in the second limiting groove. The second spring is connected to the first connecting rod. When the cam reaches the second preset speed, one end of the first connecting rod moves into the receiving hole against the elastic force of the second spring.

[0018] In the above solution, both the first sliding part and the second sliding part are restricted in the wheel body main body by springs. Only when the speed of the cam reaches the preset speed can the first sliding part and the second sliding part move away from the wheel body main body, thereby changing the structural length of the cam and reducing the working intensity of each component in the cam.

[0019] Preferably, the wheel body main body and the second sliding part are in clearance fit, and the second sliding part and the first sliding part are in clearance fit.

[0020] Among them, considering that there is lubricating oil inside the engine, the clearance fit can make it easier for the first sliding part and the second sliding part, and the second sliding part and the wheel body main body to squeeze out the lubricating oil in the engine from the connection surface during the fitting process or prevent the lubricating oil from being squeezed into the first accommodation space or the second accommodation space during the connection process.

[0021] Preferably, the storage cavity includes a chamber and a connecting chamber connected to each other. The connecting chamber is communicated with the first accommodation space. The seal is fitted with the connecting chamber, and a seal is provided on the side surface of the seal.

[0022] Preferably, the bottom surface of the second connecting rod abuts against the bottom surface of the first accommodation space, and the fluid medium is filled to the bottom surface of the seal.

[0023] In the above solution, a fluid medium is provided in the chamber, and the connecting chamber is set as a channel for sealing and transmitting the fluid medium. The cross-section of the connecting chamber is the same as the surface of the seal, and the fluid medium is filled to the bottom surface position when the seal is installed in the connecting chamber. Therefore, when the seal leaves the connecting chamber and the second connecting rod moves, the fluid medium can immediately enter the first accommodation space, ensuring that after the first connecting rod closes the storage cavity subsequently, the fluid medium fills the remaining space in the first accommodation cavity, ensuring that the position of the second connecting rod does not change, and thus ensuring that when the cam contacts the valve tappet, the changed structural length matches the rotational speed.

[0024] Preferably, the first preset speed is equal to the second preset speed.

[0025] On the other hand, an engine valve train is provided, and the engine valve train is equipped with the above-mentioned engine valve mechanism.

[0026] Compared with the existing technology, the present invention has the following beneficial effects:

[0027] 1. The cam of the present invention is connected to the drive shaft and includes a wheel body main body, a first sliding part, a second sliding part, a first connecting rod, a second connecting rod and a storage cavity. During the low-speed rotation of the cam, the stroke of the cam pushing the valve is small to match the intake requirement of the engine. When the engine speed increases, the speed of the drive shaft increases accordingly, so that the speed of the cam increases. At this time, the second sliding part gradually slides out of the cam main body as the speed increases, making the overall structure of the cam gradually grow. Therefore, when the cam contacts the valve, the valve stroke can be increased, allowing more gas to enter the engine cylinder.

[0028] 2. The storage cavity includes a connection chamber and a chamber. The connection chamber is set as a channel for sealing and transmitting a fluid medium. The cross-section of the connection chamber is the same as the surface of the seal, and the fluid medium is filled to the bottom position when the seal is installed in the connection chamber. Therefore, when the seal leaves the connection chamber and the second connecting rod moves, the fluid medium can immediately enter the first accommodation space, ensuring that after the first connecting rod closes the storage cavity subsequently, the fluid medium fills the remaining space in the first accommodation cavity, ensuring that the position of the second connecting rod does not change, so as to ensure that the changed structural length of the cam matches the speed when the cam contacts the valve tappet.

[0029] 3. Both the first sliding part and the second sliding part are restricted in the wheel body main body by springs. Only when the speed of the cam reaches the preset speed can the first sliding part and the second sliding part move away from the wheel body main body, thereby changing the structural length of the cam and reducing the working intensity of each component in the cam. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments. In all the drawings, similar elements or parts are generally denoted by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to actual scale.

[0031] Figure 1 is a schematic diagram of the overall structure of the present invention.

[0032] Figure 2 is a side view of the present invention.

[0033] Figure 3 is a cross-sectional view of the cam in an embodiment of the present invention.

[0034] Figure 4 is a schematic diagram of the first sliding part moving away from the wheel body main body in an embodiment of the present invention.

[0035] Figure 5 is a schematic diagram of the second sliding part moving away from the wheel body main body in an embodiment of the present invention.

[0036] Figure 6 It is the internal structure diagram when the cam contacts the valve in an embodiment of the present invention.

[0037] Description of main reference numerals:

[0038] 1. Cam; 2. Drive shaft; 3. Contact block; 4. Valve tappet; 5. Valve stem; 6. Second limiting mechanism; 7. First limiting mechanism; 8. Storage cavity; 101. First sliding part; 102. Second sliding part; 103. Wheel body main body; 104. Fluid medium; 105. First accommodating space; 106. Second accommodating space; 1011. First connecting rod; 1012. Second spring; 1013. Second limiting groove; 1021. Second connecting rod; 601. Block; 602. First spring; 603. First limiting groove; 701. Dredging groove; 702. Accommodating hole; 703. Seal; 801. Connecting chamber; 802. Chamber. Specific embodiments

[0039] Next, the working principle in this embodiment will be described in detail so that those skilled in the art can better understand the present invention:

[0040] Next, the working principle of this embodiment will be described in detail to enable those skilled in the art to better understand the present invention:

[0041] An embodiment of the present invention provides an engine valve mechanism. The engine valve mechanism includes a cam 1 and a drive shaft 2. The drive shaft 2 is connected to the output main shaft in the engine so that the rotational speed of the drive shaft 2 is directly proportional to the rotational speed of the output main shaft. The cam 1 includes a wheel body main body 103, a first sliding portion 101, a second sliding portion 102, a first connecting rod 1011, a second connecting rod 1021, and a storage cavity 8. The wheel body main body 103 is connected to the second sliding portion 102, and the second sliding portion 102 is connected to the first sliding portion 101. The cam 1 is formed by the wheel body main body 103 and the first sliding portion 101. A storage cavity 8 and a first accommodating space 105 communicating with the storage cavity 8 are provided in the wheel body main body 103. One end of the second connecting rod 1021 is fitted in the first accommodating space 105, and the other end is connected to the second sliding portion 102. A second accommodating space 106 is provided on both the second connecting rod 1021 and the second sliding portion 102. One end of the first connecting rod 1011 is fitted in the storage cavity 8, and the other end is connected to the first sliding portion 101. The wheel body main body 103 is connected to the drive shaft 2, and a fluid medium 104 is provided in the storage cavity 8. When the drive shaft 2 rotates, the first connecting rod 1011 moves into the first accommodating space 105, seals the second accommodating space 106, and makes the first accommodating space 105 communicate with the storage cavity 8. A first limiting mechanism 7 is provided on the first connecting rod 1011 to limit the sliding stroke of the first connecting rod 1011 in the second accommodating space 106, and a second limiting mechanism 6 is provided on the second connecting rod 1021 to limit the sliding stroke of the second connecting rod 1021 in the first accommodating space 105.

[0042] Among them, the first sliding part 101 and the second sliding part 102 are protruding structures on the cam 1 that contact the valve. They can be arc-shaped, rhombic and other structures, which can be adjusted according to the actual situation. They are installed on the wheel body main body 103 through the first connecting rod 1011 and the second connecting rod 1021. The wheel body main body 103 is installed on the drive shaft 2 connected to the output main shaft of the engine. When the engine speed increases, the rotational speeds of the drive shaft 2 and the wheel body main body 103 increase, causing the first sliding part 101 and the second sliding part 102 to move outward from the wheel body main body 103, increasing the structural length of the cam 1. When contacting the valve, the stroke of the valve can be increased. During this process, the second sliding part 102 is the basic amount of the increase in the structural length of the cam 1. The distance that the second sliding part 102 moves outward from the wheel body main body 103 is adapted to the rotational speed of the cam 1 adapting to the output main shaft of the engine. The first sliding part 101 and the first connecting rod 1011 are used to lock the second sliding part 102 before the cam 1 contacts the valve, ensuring that the length of the cam 1 structure remains unchanged during the contact time with the valve, so as to feedback the self-adaptive length change of the cam 1 to the output main shaft to the valve. Specifically, a first accommodation space 105 is provided in the wheel body main body 103. The second sliding part 102 is installed in the first accommodation space 105 through the second connecting rod 1021 and connected to the wheel body main body 103. Moreover, the second sliding part 102 and the second connecting rod 1021 jointly form a second accommodation space 106. The second accommodation space 106 penetrates through the second sliding part 102 and the second connecting rod 1021 and is connected to the first accommodation space 105. The first sliding part 101 is installed in the second accommodation space 106 through the first connecting rod 1011 and connected to the second sliding part 102. Among them, the bottom surface of the second connecting rod 1021 abuts against the bottom surface of the first accommodation space 105. The fluid medium 104 is filled to the bottom surface of the seal 703. The first connecting rod 1011 seals the second accommodation space 106. The first accommodation space 105 is connected to the storage cavity 8 in the wheel body main body 103. The fluid medium 104 can be hydraulic oil or other liquids with high fluidity. At a low rotational speed of the drive shaft 2, the first sliding part 101 is respectively controlled by the first limiting mechanism 7 and the second limiting mechanism 6 of the second sliding part 102 and cannot move away from the wheel body main body 103. During this period, the first connecting rod 1011 seals the storage cavity 8.When the drive shaft 2 rotates at a high speed, the first sliding portion 101 and the first connecting rod 1011 first move away from the wheel body main body 103, so that one end of the first connecting rod 1011 moves out of the storage cavity 8, releasing the seal of the storage cavity 8. Therefore, when the second sliding portion 102 moves away from the wheel body main body 103, the second connecting rod 1021 pumps the fluid medium 104 in the storage cavity 8 into the first accommodating space 105. When the cam 1 contacts the valve tappet 4, the first sliding portion 101 moves towards the wheel body main body 103 until the bottom surface of the first sliding portion 101 contacts the second sliding portion 102, and the first connecting rod 1011 closes the storage cavity 8, preventing the second connecting rod 1021 from moving downward and fixing the second sliding portion 102. Thus, it is ensured that during the time of contact with the valve, the length of the cam 1 structure remains unchanged, and the self-adaptive length change of the cam 1 to the output main shaft is fed back to the valve. Wherein, the wheel body main body 103 and the second sliding portion 102 are in clearance fit, and the second sliding portion 102 and the first sliding portion 101 are in clearance fit. Considering that there is lubricating oil inside the engine, the clearance fit can make it easier to squeeze the lubricating oil in the engine out of the joint surface or prevent the lubricating oil from being squeezed into the first accommodating space 105 or the second accommodating space 106 during the fitting process between the first sliding portion 101 and the second sliding portion 102, and between the second sliding portion 102 and the wheel body main body 103.

[0043] Wherein, in one implementation, the valve includes a valve tappet 44, a valve stem 5 and a contact block 3. The lower end surface of the valve tappet 4 is connected to the valve stem 5, and the contact block 3 is installed on the upper end surface. The contact block 3 is located on one side of the upper end surface of the valve tappet 4. The contact block 3 has an inclined surface tangent to the first sliding portion 101, so that before the first sliding portion 101 contacts the valve tappet 4, the first connecting rod 1011 is moved into the storage cavity 8 through the contact block 3, and the storage cavity 8 is sealed.

[0044] Among them, when the cam 1 rotates at a high speed, the first sliding portion 101 and the second sliding portion 102 move away from the wheel body main body 103, so that the structural length of the cam 1 increases. However, the first sliding portion 101 is responsible for fixing the second sliding portion 102 that moves away from the wheel body main body 103. Therefore, when the cam 1 is not in contact with the valve tappet 4, the first connecting rod 1011 is pushed into the storage cavity 8 in advance through the contact block 3 to close the storage cavity 8, and the first sliding portion 101 just abuts against the second sliding portion 102, so that the second sliding portion 102 is fixed when the cam 1 contacts the valve tappet 4. Among them, the contact surface between the contact block 3 and the first sliding portion 101 is set as an inclined surface and is tangent to the first sliding portion 101, which can make the component force when the first sliding portion 101 contacts the contact block 3 concentrate in the axial direction of the first connecting rod 1011 and reduce the wear of the first connecting rod 1011 and the second accommodating space 106.

[0045] Among them, in an embodiment of the present invention, the first limiting mechanism 7 includes a receiving hole 702, a sealing member 703, and a dredging groove 701; one end of the second connecting rod 1021 is provided with the receiving hole 702, one end of the first connecting rod 1011 is provided with the sealing member 703, the dredging groove 701 is provided on the inner wall of the receiving hole 702, and the sealing member 703 is fitted with the receiving hole 702 to limit the movement of the first connecting rod 1011. Among them, the sealing member 703 is fitted in the receiving hole 702, and its shape and size can be changed according to actual applications, and it is required to satisfy that the second accommodation space 106 is sealed when the sealing member 703 is fitted in the receiving hole 702. The first connecting rod 1011 is limited by the sealing member 703 fitted in the receiving hole 702 to ensure that the first connecting rod 1011 and the first sliding portion 101 will not be thrown out of the wheel body main body 103. The dredging groove 701 on the inner wall of the receiving hole 702 can make it so that when the second connecting rod 1021 withdraws the fluid medium 104, even if the first connecting rod 1011 moves, the volume between the bottom surface of the second connecting rod 1021 and the first accommodation space 105 remains unchanged, thereby ensuring that the amount by which the second sliding portion 102 extends out of the wheel body main body 103 matches the rotational speed. Among them, in one implementation manner, the second sliding portion 102 is provided with a second limiting groove 1013, a second spring 1012 is provided in the second limiting groove 1013, the second spring 1012 is connected to the first connecting rod 1011, and when the cam 1 reaches the second preset speed, one end of the first connecting rod 1011 moves into the receiving hole 702 against the elastic force of the second spring 1012. Among them, when the first sliding portion 101 and the second sliding portion 102 are in the initial position, the stroke of the cam 1 pushing the valve is the smallest, and this stroke matches the low rotational speed of the output main shaft, and the cam 1 does not need to change the structural length. Therefore, the elastic force of the second spring 1012 can be set as the prerequisite for the first sliding portion 101 to move away from the wheel body main body 103, thereby avoiding the ineffective work of the first sliding portion 101 and the first connecting rod 1011 and improving the service life. Among them, the storage cavity 8 can be set to include a connection chamber 801 and a chamber 802. The connection chamber 801 is set as a channel for sealing and transmitting the fluid medium 104. The cross-section of the connection chamber 801 is the same as the surface of the sealing member 703, and the fluid medium 104 is filled to the bottom surface position when the sealing member 703 is installed in the connection chamber 801. Therefore, when the sealing member 703 leaves the connection chamber 801 and the second connecting rod 1021 moves, the fluid medium 104 can immediately enter the first accommodation space 105, ensuring that after the first connecting rod 1011 closes the storage cavity 8 subsequently, the fluid medium 104 fills the remaining space in the first accommodation cavity, ensuring that the position of the second connecting rod 1021 does not change, and thus ensuring that when the cam 1 contacts the valve tappet 4, the changed structural length matches the rotational speed.

[0046] Similarly, in this embodiment, the second limiting mechanism 6 includes a first limiting groove 603, a clamping block 601, and a first spring 602; the wheel body main body 103 is provided with the first limiting groove 603, the first limiting groove 603 communicates with the first accommodating space 105, the second connecting rod 1021 is provided with the clamping block 601 that fits with the first limiting groove 603, and the first spring 602 is arranged in the first limiting groove 603. When the cam 1 reaches the first preset speed, the second connecting rod 1021 moves out of the first accommodating space 105 against the elastic force of the first spring 602.

[0047] Among them, the first limiting groove 603 can be set as a cylindrical hole with a diameter larger than that of the first connecting rod 1011. The second limiting groove 1013 can be a cylindrical through hole with a diameter larger than that of the second connecting rod 1021, or can be a plurality of holes distributed around the first connecting rod 1011 or the second connecting rod 1021. The first connecting rod 1011 or the second connecting rod 1021 are respectively connected to the second spring 1012 and the first spring 602, so that the ineffective work of the first sliding part 101 and the second sliding part 102 with the first connecting rod 1011 and the second connecting rod 1021 is reduced, and the service life is improved. Among them, although the first sliding part 101 is arranged outside the second sliding part 102, due to the influence of their masses, it cannot be ensured that the first sliding part 101 can move away from the wheel body main body 103 preferentially. Therefore, the second preset speed can be set to be less than the first preset speed, or the first preset speed and the second preset speed can be the same. Such a setting can ensure that the first sliding part 101 takes precedence over the second sliding part 102, and ensure that the opening and closing of the storage cavity 8 by the first connecting rod 1011 can match the movement of the second connecting rod 1021. Ensure the normal operation of the valve mechanism in the embodiment of the present invention.

[0048] Working principle:

[0049] Reference Figure 3 , when the drive shaft 2 rotates at a low speed, the first limiting mechanism 7 and the second limiting mechanism 6 restrain the first sliding part 101 and the second sliding part 102 in the wheel body main body 103. At this time, the structural length of the cam 1 remains unchanged, and the stroke of the valve remains unchanged. When the drive shaft 2 rotates at a high speed, that is, reaches the second preset speed, the first sliding part 101 moves away from the wheel body main body 103 first against the elastic force of the second spring 1012. During this process, reference Figure 4 , the first connecting rod 1011 drives the seal 703 to move towards the receiving hole 702 until the seal 703 is completely removed from the connecting chamber 801 and embedded in the receiving hole 702, releasing the closure of the storage cavity 8. Further, the second sliding part 102 moves away from the wheel body main body 103 against the elastic force of the first spring 602. During this process, reference Figure 5, the first connecting rod 1011 and the second connecting rod 1021 move together, creating a negative pressure in the first accommodating space 105. The fluid medium 104 in the chamber 802 enters the first accommodating space 105 through the connecting chamber 801. At this time, the cam 1 is not in contact with the valve tappet 4. When the cam 1 contacts the contact block 3 on the valve tappet 4, refer to Figure 6 , the first sliding part 101 moves towards the wheel body main body 103, causing the first connecting rod 1011 to move towards the connecting chamber 801. During this process, the seal 703 disengages from the receiving hole 702. Under the action of the dredging groove 701, the fluid medium 104 in the first accommodating space 105 replenishes the receiving hole 702, keeping the volume of the fluid medium 104 in the first accommodating space 105 unchanged and ensuring that the distance by which the second sliding part 102 extends from the wheel body main body 103 remains unchanged. When the first sliding part 101 contacts the valve tappet 4, the seal 703 enters the connecting chamber 801 and closes the connecting chamber 801. Therefore, the second sliding part 102 cannot move downward under the action of the fluid medium 104. At this time, the distance by which the second sliding part 102 extends from the wheel body main body 103 is the structural length changed by the cam 1. As the structural length of the cam 1 increases, the valve stroke also increases, and the distance by which the second sliding part 102 extends from the wheel body main body 103 increases with the increase in the rotational speed of the drive shaft 2, achieving stepless adjustment of the valve stroke. When the cam 1 disengages from the valve tappet 4, refer to Figure 5 , the first sliding part 101 moves away from the wheel body main body 103 again, and this cycle repeats.

[0050] The foregoing description of the specific exemplary embodiments of the present invention is for the purposes of illustration and exemplification. These descriptions are not intended to limit the present invention to the precise forms disclosed, and obviously, many changes and variations can be made in light of the above teachings. Although the embodiments of the present invention have been shown and described, the specific embodiments are merely interpretations of the present invention and not limitations thereof. The specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical applications, so that those skilled in the art can, after reading this specification, make modifications, substitutions, variations, and various different selections and changes that do not contribute creatively to the embodiments as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. An engine valve mechanism, characterized in that: The engine valve mechanism comprises a cam (1) and a drive shaft (2); the drive shaft (2) is connected to an output main shaft in the engine; The cam (1) comprises a wheel body (103), a first sliding part (101), a second sliding part (102), a first connecting rod (1011), a second connecting rod (1021) and a storage chamber (8); the wheel body (103) is connected to the second sliding part (102), the second sliding part (102) is connected to the first sliding part (101), and the wheel body (103) and the first sliding part (101) form the cam (1), and the wheel body (103) is provided with The storage cavity (8) and a first accommodating space (105) communicated with the storage cavity (8), one end of the second connecting rod (1021) is embedded in the first accommodating space (105), and the other end is connected to the second sliding part (102), the second connecting rod (1021) and the second sliding part (102) are jointly provided with a second accommodating space (106), one end of the first connecting rod (1011) is embedded in the storage cavity (8), and the other end is connected to the first sliding part (101); The wheel body (103) is connected to the drive shaft (2), and a fluid medium (104) is arranged in the storage chamber (8); a first limiting mechanism (7) is arranged on the first connecting rod (1011) for limiting the sliding stroke of the first connecting rod (1011) in the second accommodating space (106); and a second limiting mechanism (6) is arranged on the second connecting rod (1021) for limiting the sliding stroke of the second connecting rod (1021) in the first accommodating space (105).

2. The engine valve train according to claim 1, characterized in that: The engine valve mechanism also includes a valve, which includes a valve tappet (4), a valve stem (5) and a contact block (3). The lower end surface of the valve tappet (4) is connected to the valve stem (5), and the upper end surface is equipped with the contact block (3). The contact block (3) is located on one side of the upper end surface of the valve tappet (4). The contact block (3) has an inclined surface tangent to the first sliding portion (101), so that before the first sliding portion (101) contacts the valve tappet (4), the first connecting rod (1011) is moved into the storage chamber (8) by the contact block (3) and the storage chamber (8) is sealed.

3. The engine valve train according to claim 1, characterized in that: The first limiting mechanism (7) comprises a receiving hole (702), a sealing member (703) and a clearing groove (701); the receiving hole (702) is provided at one end of the second connecting rod (1021), the sealing member (703) is provided at one end of the first connecting rod (1011), the clearing groove (701) is provided on the inner wall of the receiving hole (702), and the sealing member (703) is engaged with the receiving hole (702) to seal the second receiving space (106).

4. The engine valve train according to claim 3, characterized in that: The second limiting mechanism (6) comprises a first limiting groove (603), a block (601) and a first spring (602); the first limiting groove (603) is arranged on the wheel body (103), the first limiting groove (603) is communicated with the first accommodating space (105), the second connecting rod (1021) is provided with the block (601) which is mutually engaged with the first limiting groove (603), the first spring (602) is arranged in the first limiting groove (603), and when the cam (1) reaches a first preset speed, the second connecting rod (1021) overcomes the elastic force of the first spring (602) and moves out of the first accommodating space (105).

5. The engine valve train according to claim 4, characterized in that: The second sliding portion (102) is provided with a second limiting groove (1013), the second limiting groove (1013) is provided with a second spring (1012), the second spring (1012) is connected to the first connecting rod (1011), and when the cam (1) reaches a second preset speed, one end of the first connecting rod (1011) overcomes the elastic force of the second spring (1012) and moves into the accommodating hole (702).

6. The engine valve train according to claim 1, characterized in that: The wheel body (103) and the second sliding part (102) are in clearance fit, and the second sliding part (102) and the first sliding part (101) are in clearance fit.

7. The engine valve train according to claim 3, characterized in that: The storage cavity (8) comprises a chamber (802) and a connecting chamber (801) which are connected to each other, the connecting chamber (801) is in communication with the first accommodating space (105), the sealing member (703) is engaged with the connecting chamber (801), and a sealing member (703) is provided on the side of the sealing member (703).

8. The engine valve train according to claim 7, characterized in that: The bottom surface of the second connecting rod (1021) abuts against the bottom surface of the first accommodating space (105), and the fluid medium (104) is filled to the bottom surface of the sealing member (703).

9. The engine valve train according to claim 5, characterized in that: The first preset speed is equal to the second preset speed.

10. An engine valve mechanism, characterized in that: The engine valve mechanism comprises the engine valve mechanism as claimed in any one of claims 1-9.

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