Single-piston hydraulic variable valve driving structure

Abstract

The invention relates to a single-piston hydraulic variable valve driving structure. The driving control unit comprises a valve body, a first valve and a second valve, and a low-pressure oil way and a high-pressure oil way are arranged in the valve body; wherein the first valve is mounted on the valve body and is used for opening a low-pressure oil way, so that low-pressure oil enters the low-pressure oil way; the second valve is arranged between the low-pressure oil way and the high-pressure oil way and can be opened through oil pressure of low-pressure oil in the low-pressure oil way so that the high-pressure oil can enter the high-pressure oil way. The driving unit comprises a driving cylinder sleeve and a driving piston which are installed on the valve body, the driving cylinder sleeve is provided with a containing hole communicated with the high-pressure oil way, and the driving piston is partially connected into the containing hole in a sliding mode; and the valve assembly is in contact fit with the driving piston, and the position of the driving piston is adjusted through high-pressure oil in the high-pressure oil way so as to adjust the opening degree of the valve assembly. The structure is simple, and the valve timing and the valve overlap angle of each working condition of the engine can be more reasonably matched, so that the system power consumption is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of engines, and in particular to a single-piston hydraulic variable valve driving structure. Background Art

[0002] The existing hydraulically driven variable valve drive structure is mainly used in engines, which improves the efficiency and power output of the engine under different working conditions by changing the engine's valve timing and valve lift.

[0003] However, the existing hydraulic drive structure usually adopts a complex oil circuit design, which makes the design and manufacture of the system complicated and costly. Secondly, the complex oil circuit design may cause slow hydraulic response and reduced accuracy during engine operation, especially in the control of the engine valve overlap angle, which will directly affect the engine's fuel efficiency and emission performance. In addition. Under certain working conditions, the power consumption of the existing hydraulic drive structure is relatively large, which not only increases the energy consumption of the system, but also affects the stability and durability of the system. Summary of the invention

[0004] To this end, the present invention provides a single-piston hydraulic variable valve drive structure, which has a simple structure and can more reasonably match the valve timing phase and valve overlap angle of various engine working conditions, thereby reducing system power consumption.

[0005] In order to solve the above technical problems, the present invention provides a single-piston hydraulic variable valve driving structure, comprising: A drive control unit, comprising a valve body, a first valve and a second valve, wherein the valve body is provided with a low-pressure oil circuit and a high-pressure oil circuit; wherein the first valve is mounted on the valve body and is used to open the low-pressure oil circuit so that low-pressure oil enters the low-pressure oil circuit; the second valve is arranged between the low-pressure oil circuit and the high-pressure oil circuit and can be opened by the oil pressure of the low-pressure oil in the low-pressure oil circuit so that high-pressure oil enters the high-pressure oil circuit; A driving unit, comprising a driving cylinder sleeve and a driving piston mounted on the valve body, wherein the driving cylinder sleeve is provided with a receiving hole communicating with the high-pressure oil circuit, and the driving piston is partially slidably connected in the receiving hole; The valve assembly is in contact with and cooperates with the driving piston, and the position of the driving piston is adjusted by the high-pressure oil in the high-pressure oil circuit to adjust the opening of the valve assembly.

[0006] In one embodiment of the present invention, a multi-stage buffer annular surface is sequentially arranged axially on the outer wall of one end of the driving piston away from the valve assembly, the high-pressure oil circuit includes a high-pressure oil hole, the driving piston can extend into the high-pressure oil hole to form a throttling buffer annular groove between the buffer annular surface and the high-pressure oil hole, and the diameters of the multi-stage buffer annular surfaces sequentially increase along the direction away from the high-pressure oil hole.

[0007] In one embodiment of the present invention, the buffer ring surface is provided with two levels, including a primary buffer ring surface and a secondary buffer ring surface, the diameter of the primary buffer ring surface is smaller than the diameter of the secondary buffer ring surface, the primary buffer ring surface can form a first throttling buffer ring groove with the high-pressure oil hole, and the secondary buffer ring surface can form a second throttling buffer ring groove with the high-pressure oil hole.

[0008] In one embodiment of the present invention, the outer side wall of the driving piston is further provided with a positioning ring wall which is connected with the multi-stage buffer ring surface and is slidably fitted in the high-pressure oil hole.

[0009] In one embodiment of the present invention, the outer wall of the driving cylinder sleeve is provided with a mounting through hole which is connected to the accommodating hole and is coaxially arranged, the driving piston extends into and is slidably connected to the mounting through hole, a limiting surface is formed between the mounting through hole and the accommodating hole, and the side wall of the driving piston radially extends with an annular protrusion which slides with the accommodating hole and can be against the limiting surface.

[0010] In one embodiment of the present invention, an axial oil hole is axially arranged along one end of the driving piston away from the valve assembly, one end of the axial oil hole is connected to the accommodating hole, and the other end extends to a side of the annular protrusion close to the mounting through hole, and a radial oil hole connected to the other end of the axial oil hole is radially arranged along the driving piston, and when the annular protrusion abuts against the limiting surface, the radial oil hole is located in the mounting through hole.

[0011] In one embodiment of the present invention, the valve body is provided with a first valve hole and a second valve hole, the first valve includes a first valve core movably disposed in the first valve hole, and the second valve includes a second valve core movably disposed in the first valve hole; The low-pressure oil circuit includes a low-pressure oil inlet, a low-pressure ring groove, a low-pressure oil channel, and a low-pressure oil channel; The high-pressure oil circuit includes a high-pressure oil inlet, a high-pressure ring groove, a high-pressure oil hole, an oil return hole, and an oil return ring groove; The low-pressure annular groove is formed between the first valve core and the first valve hole, the low-pressure oil inlet is arranged on the outer side wall of the valve body and can be communicated with the low-pressure annular groove, one side of the low-pressure oil passage can be communicated with the low-pressure annular groove or the external atmosphere, and the other side is communicated with the second valve hole; The high-pressure annular groove is formed between the second valve core and the second valve hole, the oil return hole is arranged on the outer side wall of the valve body and communicates with the atmosphere, the high-pressure oil inlet is arranged on the outer side wall of the valve body and can communicate with the high-pressure annular groove, the high-pressure annular groove is communicated with the high-pressure oil hole, and the oil return annular groove can communicate with the oil return hole; Wherein, when the first valve core is in the first position, the low-pressure oil inlet, the low-pressure ring groove and the low-pressure oil channel are connected in sequence, and the second valve core can be moved to the second position; When the second valve core is in the second position, the high-pressure oil inlet, the high-pressure ring groove and the high-pressure oil hole are connected in sequence; When the first valve core is in the third position, the low-pressure oil inlet and the low-pressure annular groove, as well as the low-pressure annular groove and the low-pressure oil passage are separated by the first valve core, the low-pressure oil passage is connected to the external atmosphere, and the second valve core can be moved to the fourth position; When the second valve core is in the fourth position, the high-pressure oil inlet and the high-pressure ring groove are separated by the second valve core, and the high-pressure oil hole, the oil return ring groove, the oil return hole and the external atmosphere are connected in sequence.

[0012] In one embodiment of the present invention, the first valve further comprises a first spring, an electromagnet component and an armature, wherein the armature is connected to the first valve core, the armature cooperates with the electromagnet component, and the first spring is used to provide a force for the first valve core to move away from the electromagnet component.

[0013] In one embodiment of the present invention, the valve body is provided with a mounting groove connected to the second valve hole, and the second valve also includes a second spring installed in the mounting groove and connected to the second valve core, and the second spring is used to provide a force for the second valve core to approach the low-pressure oil channel.

[0014] In one embodiment of the present invention, the valve assembly includes a valve rod, a valve spring and a valve spring seat, the valve rod is telescopically connected to the valve spring seat through the valve spring, and the valve rod abuts against the driving piston.

[0015] The above technical solution of the present invention has the following advantages compared with the prior art: The single-piston hydraulic variable valve drive structure described in the present invention has a simple and compact structure compared to the traditional complex oil circuit design, and can greatly reduce the complexity of the manufacturing and assembly processes, which not only reduces the manufacturing difficulty and cost of the system, but also improves the reliability and stability of the system.

[0016] The present invention optimizes the response speed of the hydraulic system, reduces the hydraulic lag phenomenon, and the multi-stage throttling buffer ring groove design of the driving piston enables the valve to smoothly transition during the opening and closing process, effectively avoiding the impact phenomenon of the hydraulic system and improving the control accuracy of the hydraulic system.

[0017] The present invention realizes fine adjustment of the valve overlap angle by designing a multi-stage buffer ring surface of the driving piston. The optimized adjustment of the valve overlap angle can effectively improve the combustion efficiency and power output of the engine under different working conditions, reduce fuel consumption, and reduce emissions. The multi-stage buffer ring surface can slow down the front end speed of the valve opening and the end speed of the valve closing, so that the engine can maintain the best working state under various working conditions.

[0018] The design of the first valve and the second valve of the present invention can achieve precise control of low-pressure oil and high-pressure oil. The first valve is used to open the low-pressure oil circuit to allow low-pressure oil to enter the system, and the second valve opens the high-pressure oil circuit through the pressure of the low-pressure oil to allow high-pressure oil to enter the system. The dual-valve control structure simplifies the oil circuit design of the system, reduces the response time of the hydraulic system, improves the control accuracy, and helps to achieve more precise valve operation; the valve body is provided with a first valve hole and a second valve hole, and the movable setting of the first valve core and the second valve core is cooperated to form a low-pressure oil circuit and a high-pressure oil circuit, so that the system can quickly switch the oil circuit under different oil pressure conditions, provide efficient hydraulic switching and control functions, and optimize the response speed and control accuracy of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0020] Figure 1 It is a schematic diagram of the single-piston hydraulic variable valve drive structure of the present invention.

[0021] Figure 2 It is a schematic diagram of the open state of the single-piston hydraulic variable valve drive structure of the present invention.

[0022] Figure 3 The closing process of the single-piston hydraulic variable valve drive structure of the present invention is schematically shown. Figure 1 .

[0023] Figure 4 for Figure 3 A partial enlarged view of .

[0024] Figure 5 The closing process of the single-piston hydraulic variable valve drive structure of the present invention is schematically shown. Figure 2 .

[0025] Figure 6 This is an assembly positioning diagram of the drive piston of the present invention.

[0026] Description of the Figures in the Specification: A. Drive control unit; B. Drive unit; C. Valve assembly; 1. First spring; 2. Electromagnet component; 3. Armature; 40. First valve; 4. First valve core; 5. Valve body; 60. Second valve; 6. Second valve core; 7. Second spring; 8. Drive cylinder sleeve; 9. Drive piston; 10. Valve stem; 11. Valve spring; 12. Valve spring seat; 501, low-pressure oil inlet; 502, low-pressure ring groove; 503, low-pressure oil channel; 504, low-pressure oil channel; 505, high-pressure oil inlet; 506, high-pressure ring groove; 507, high-pressure oil hole; 508, oil return hole; 509, oil return ring groove; 801, high pressure oil circuit; 802, limit surface; 803, accommodation hole; 804, installation through hole; 901, axial oil hole; 902, radial oil hole; 903, first throttling buffer ring groove; 904, second throttling buffer ring groove; 905, primary buffer ring surface; 906, secondary buffer ring surface; 907, positioning ring wall. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0028] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0029] In the present invention, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present invention, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0030] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0031] Reference Figure 1, Figure 2 As shown, a single-piston hydraulic variable valve driving structure of the present invention comprises: The driving control unit A comprises a valve body 5, a first valve 40 and a second valve 60, wherein the valve body 5 is provided with a low-pressure oil circuit and a high-pressure oil circuit 801; wherein the first valve 40 is mounted on the valve body 5 and is used to open the low-pressure oil circuit so that low-pressure oil enters the low-pressure oil circuit; the second valve 60 is arranged between the low-pressure oil circuit and the high-pressure oil circuit 801, and can be opened by the oil pressure of the low-pressure oil in the low-pressure oil circuit so that high-pressure oil enters the high-pressure oil circuit 801; The driving unit B comprises a driving cylinder sleeve 8 and a driving piston 9 mounted on the valve body 5, wherein the driving cylinder sleeve 8 is provided with a receiving hole 803 communicating with the high-pressure oil circuit 801, and the driving piston 9 is partially slidably connected in the receiving hole 803; The valve assembly C contacts and cooperates with the driving piston 9 , and the position of the driving piston 9 is adjusted by the high-pressure oil in the high-pressure oil circuit 801 to adjust the opening of the valve assembly C.

[0032] In one embodiment, the outer wall of the end of the driving piston 9 away from the valve assembly C is sequentially provided with multiple buffer annular surfaces in the axial direction, the high-pressure oil circuit 801 includes a high-pressure oil hole 507, and the driving piston 9 can extend into the high-pressure oil hole 507, so that a throttling buffer annular groove is formed between the buffer annular surface and the high-pressure oil hole 507, and the diameters of the multiple buffer annular surfaces in the direction away from the high-pressure oil hole 507 are sequentially increased. The setting of the multiple throttling buffer annular grooves can provide hydraulic buffering, slow down the front end speed of valve opening and the end speed of valve closing, and facilitate the adjustment of the valve overlap angle under different working conditions.

[0033] Reference Figure 4 As shown, exemplarily, the buffer annulus is provided with two levels, including a primary buffer annulus 905 and a secondary buffer annulus 906, the diameter of the primary buffer annulus 905 is smaller than the diameter of the secondary buffer annulus 906; the primary buffer annulus 905 can form a first throttling buffer annular groove 903 with the high-pressure oil hole 507, and the secondary buffer annular surface 906 can form a second throttling buffer annular groove 904 with the high-pressure oil hole 507.

[0034] Specifically, the outer side wall of the driving piston 9 is further provided with a positioning ring wall 907 which is connected with the multi-stage buffer ring surface and is slidably fitted in the high-pressure oil hole 507 .

[0035] By adopting a three-stage outer circle structure on the head of the driving piston 9, the first two stages are used for hydraulic buffering to slow down the front end speed of valve opening and the end speed of valve closing, which is convenient for adjusting the valve overlap angle under different working conditions; the third stage outer circle is used for assembly positioning with the valve body 5 to avoid wear between the driving piston 9 and the matching hole of the valve body 5 during the up and down movement, thereby improving the stability of the valve overlap angle and also helping to increase the service life of the driving piston 9 and enhance the engine performance.

[0036] In one embodiment, the outer wall of the driving cylinder sleeve 8 is provided with a mounting through hole 804 which is connected to the accommodating hole 803 and is coaxially arranged. The driving piston 9 extends into and is slidably connected to the mounting through hole 804. A limiting surface 802 is formed between the mounting through hole 804 and the accommodating hole 803. The side wall of the driving piston 9 radially extends with an annular protrusion which slides with the accommodating hole 803 and can abut against the limiting surface 802.

[0037] In one embodiment, referring to Figure 2 As shown, an axial oil hole 901 is axially arranged along one end of the driving piston 9 away from the valve assembly C, one end of the axial oil hole 901 is connected to the accommodating hole 803, and the other end extends to the side of the annular convex body close to the mounting through hole 804, and a radial oil hole 902 is radially arranged along the driving piston 9 and is connected to the other end of the axial oil hole 901. When the annular convex body abuts against the limiting surface 802, the radial oil hole 902 is located in the mounting through hole 804. The arrangement of the axial oil hole 901 and the radial oil hole 902 on the driving piston 9 enables the hydraulic oil to be effectively circulated and adjusted in different positions and states.

[0038] In one embodiment, referring to Figure 2 , Figure 3 As shown, the valve body 5 is provided with a first valve hole 40 and a second valve hole 60, the first valve 40 includes a first valve core 4 movably disposed in the first valve hole 40, and the second valve 60 includes a second valve core 6 movably disposed in the first valve hole 40; The low-pressure oil circuit includes a low-pressure oil inlet 501, a low-pressure ring groove 502, a low-pressure oil passage 504, and a low-pressure oil passage 504; The high-pressure oil circuit 801 includes a high-pressure oil inlet 505, a high-pressure ring groove 506, a high-pressure oil hole 507, an oil return hole 508, and an oil return ring groove 509; The low-pressure annular groove 502 is formed between the first valve core 4 and the first valve 40 hole, the low-pressure oil inlet 501 is arranged on the outer side wall of the valve body 5 and can be communicated with the low-pressure annular groove 502, one side of the low-pressure oil passage 504 can be communicated with the low-pressure annular groove 502 or the external atmosphere, and the other side is communicated with the second valve 60 hole; The high-pressure annular groove 506 is formed between the second valve core 6 and the second valve 60 hole, the oil return hole 508 is arranged on the outer wall of the valve body 5 and communicates with the atmosphere, the high-pressure oil inlet 505 is arranged on the outer wall of the valve body 5 and can be communicated with the high-pressure annular groove 506, the high-pressure annular groove 506 is communicated with the high-pressure oil hole 507, and the oil return annular groove 509 can be communicated with the oil return hole 508; When the first valve core 4 is in the first position, the low-pressure oil inlet 501, the low-pressure annular groove 502 and the low-pressure oil passage 504 are connected in sequence, and the second valve core 6 can be moved to the second position; When the second valve core 6 is in the second position, the high-pressure oil inlet 505, the high-pressure annular groove 506 and the high-pressure oil hole 507 are connected in sequence; When the first valve core 4 is in the third position, the low-pressure oil inlet 501 and the low-pressure annular groove 502 and the low-pressure annular groove 502 and the low-pressure oil passage 504 are blocked by the first valve core 4, the low-pressure oil passage 504 is connected to the external atmosphere, and the second valve core 6 can be moved to the fourth position; When the second valve core 6 is in the fourth position, the high-pressure oil inlet 505 and the high-pressure annular groove 506 are separated by the second valve core 6, and the high-pressure oil hole 507, the oil return annular groove 509, the oil return hole 508 and the external atmosphere are connected in sequence.

[0039] It should be noted that the first valve 40 has a sealing seat extending radially outward, which cooperates with the sealing end face on one side of the hole of the first valve 40, and one side of the hole of the first valve 40 is connected to the external atmosphere; in addition, the formation of the low-pressure ring groove 502, the high-pressure ring groove 506, and the return oil ring groove 509 can be achieved by setting corresponding grooves on the first valve core 4 / first valve 40 hole and the second valve core 6 / second valve 60 hole.

[0040] Reference Figure 2 As shown, the first valve 40 also includes a first spring 1, an electromagnetic component 2 and an armature 3, the armature 3 is connected to the first valve core 4, the armature 3 cooperates with the electromagnetic component 2, and the first spring 1 is used to provide a force for the first valve core 4 to move away from the electromagnetic component 2.

[0041] The valve body 5 is provided with a mounting groove connected to the hole of the second valve 60. The second valve 60 also includes a second spring 7 installed in the mounting groove and connected to the second valve core 6. The second spring 7 is used to provide a force for the second valve core 6 to approach the low-pressure oil channel 504.

[0042] Specifically, the first piston is installed in the first valve 40 hole on the left side of the valve body 5 by using a mating part; the second piston is installed in the second valve 60 hole on the right side of the valve body 5 by using a mating part.

[0043] The design of the first valve 40 and the second valve 60 can achieve precise control of low-pressure oil and high-pressure oil. The first valve 40 is used to open the low-pressure oil circuit to allow low-pressure oil to enter the system, and the second valve 60 opens the high-pressure oil circuit 801 through the pressure of the low-pressure oil to allow high-pressure oil to enter the system. The dual-valve control structure simplifies the oil circuit design of the system, reduces the response time of the hydraulic system, improves the control accuracy, and helps to achieve more precise valve operation.

[0044] The valve body 5 is provided with a first valve hole 40 and a second valve hole 60, which cooperate with the movable setting of the first valve core 4 and the second valve core 6 to form a low-pressure oil circuit and a high-pressure oil circuit 801, so that the system can quickly switch the oil circuit under different oil pressure conditions, provide efficient hydraulic switching and control functions, and optimize the response speed and control accuracy of the system.

[0045] In one embodiment, the valve assembly C includes a valve rod, a valve spring 11 and a valve spring seat 12 . The valve rod is telescopically connected to the valve spring seat 12 through the valve spring 11 , and the valve rod abuts against the driving piston 9 .

[0046] Working principle: like Figure 2 As shown, the electromagnet component 2 is energized to provide a leftward electromagnetic force, the armature 3 overcomes the spring force of the first spring 1 and drives the first piston to move leftward, the low-pressure ring groove 502 oil circuit is opened, and the low-pressure oil enters the low-pressure oil channel 504 from the low-pressure oil inlet 501 through the low-pressure ring groove 502, and then flows to the low-pressure oil channel 504, the left side of the second piston overcomes the second spring 7 and moves rightward under the action of the hydraulic pressure, the high-pressure ring groove 506 is opened, and the hydraulic oil of the high-pressure oil inlet 505 enters the high-pressure oil hole 507 through the high-pressure ring groove 506, and then enters the high-pressure oil circuit 801, the driving piston 9 overcomes the spring force of the valve spring 11 under the action of the hydraulic pressure and moves downward, and the size of the downward opening of the valve is controlled by controlling the size of the hydraulic pressure, and when the driving piston 9 moves to the limit surface 802 and stops, the valve is fully opened.

[0047] like Figure 3 , Figure 4 , Figure 5As shown, the electromagnet component 2 is powered off, the electromagnetic force is released, the first piston moves rightward under the spring force of the first spring 1, the low-pressure ring groove 502 oil circuit is closed, the hydraulic oil in the low-pressure oil channel 504 is connected to the atmosphere and the oil pressure is released, the second piston moves leftward under the spring force of the second spring 7, the high-pressure ring groove 506 is closed, the return oil ring groove 509 is opened, and the hydraulic oil in the high-pressure oil circuit 801 and the high-pressure oil hole 507 flows into the return oil hole 508 through the return oil ring groove 509 and is connected to the external atmosphere. At the same time, the driving piston 9 moves upward under the action of the spring force of the valve spring 11 until the driving piston 9 moves to the state shown in the figure, and the high-pressure oil in the high-pressure oil circuit 801 flows out from the first throttling buffer ring groove 903, generating a first-level throttling buffer, and the driving piston 9 starts to decelerate upward; when the driving piston 9 moves upward to the state shown in the figure, the high-pressure oil in the high-pressure oil circuit 801 flows out from the second throttling buffer ring groove 904, generating a second-level throttling buffer, until the driving piston 9 decelerates and stops, and the valve is closed.

[0048] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A single-piston hydraulic variable valve drive structure, characterized in that: include: A drive control unit (A) comprises a valve body (5), a first valve (40) and a second valve (60), wherein the valve body (5) is provided with a low-pressure oil circuit and a high-pressure oil circuit (801) therein; wherein the first valve (40) is mounted on the valve body (5) and is used to open the low-pressure oil circuit so that low-pressure oil enters the low-pressure oil circuit; and the second valve (60) is arranged between the low-pressure oil circuit and the high-pressure oil circuit (801) and can be opened by the oil pressure of the low-pressure oil in the low-pressure oil circuit so that high-pressure oil enters the high-pressure oil circuit (801); A drive unit (B) comprising a drive cylinder sleeve (8) and a drive piston (9) mounted on the valve body (5), wherein the drive cylinder sleeve (8) is provided with a receiving hole (803) communicating with the high-pressure oil circuit (801), and the drive piston (9) is partially slidably connected in the receiving hole (803); The valve assembly (C) is in contact with the driving piston (9), and the position of the driving piston (9) is adjusted by the high-pressure oil in the high-pressure oil circuit (801), so as to adjust the opening of the valve assembly (C).

2. A single-piston hydraulic variable valve drive structure according to claim 1, characterized in that: The outer wall of one end of the driving piston (9) away from the valve assembly (C) is provided with a plurality of buffer annular surfaces in sequence along the axial direction; the high-pressure oil circuit (801) comprises a high-pressure oil hole (507); the driving piston (9) can extend into the high-pressure oil hole (507) so that a throttling buffer annular groove is formed between the buffer annular surface and the high-pressure oil hole (507); and the diameters of the plurality of buffer annular surfaces increase in sequence along a direction away from the high-pressure oil hole (507).

3. A single-piston hydraulic variable valve drive structure according to claim 2, characterized in that: The buffer annular surface is provided with two levels, including a primary buffer annular surface (905) and a secondary buffer annular surface (906); the diameter of the primary buffer annular surface (905) is smaller than the diameter of the secondary buffer annular surface (906); the primary buffer annular surface (905) can form a first throttling buffer annular groove (903) with the high-pressure oil hole (507); and the secondary buffer annular surface (906) can form a second throttling buffer annular groove (904) with the high-pressure oil hole (507).

4. The single-piston hydraulic variable valve drive structure according to claim 2, characterized in that: The outer side wall of the driving piston (9) is also provided with a positioning ring wall (907) that is connected to the multi-stage buffer ring surface and is slidably fitted to the high-pressure oil hole (507).

5. The single-piston hydraulic variable valve drive structure according to claim 1, characterized in that: The outer wall of the drive cylinder sleeve (8) is provided with a mounting through hole (804) which is connected to the accommodating hole (803) and is coaxially arranged. The drive piston (9) extends into and is slidably connected to the mounting through hole (804). A limiting surface (802) is formed between the mounting through hole (804) and the accommodating hole (803). The side wall of the drive piston (9) radially extends with an annular protrusion which is slidably matched with the accommodating hole (803) and can abut against the limiting surface (802).

6. The single-piston hydraulic variable valve drive structure according to claim 5, characterized in that: An axial oil hole (901) is axially arranged along one end of the driving piston (9) away from the valve assembly (C); one end of the axial oil hole (901) is connected to the accommodating hole (803), and the other end extends to a side of the annular protrusion close to the mounting through hole (804); a radial oil hole (902) is radially arranged along the driving piston (9) and is connected to the other end of the axial oil hole (901); when the annular protrusion abuts against the limiting surface (802), the radial oil hole (902) is located in the mounting through hole (804).

7. The single-piston hydraulic variable valve drive structure according to claim 1, characterized in that: The valve body (5) is provided with a first valve (40) hole and a second valve (60) hole, the first valve (40) comprising a first valve core (4) movably arranged in the first valve (40) hole, and the second valve (60) comprising a second valve core (6) movably arranged in the first valve (40) hole; The low-pressure oil circuit comprises a low-pressure oil inlet (501), a low-pressure ring groove (502), a low-pressure oil passage (504), and a low-pressure oil passage (504); The high-pressure oil circuit (801) comprises a high-pressure oil inlet (505), a high-pressure ring groove (506), a high-pressure oil hole (507), an oil return hole (508), and an oil return ring groove (509); The low-pressure annular groove (502) is formed between the first valve core (4) and the first valve (40) hole, the low-pressure oil inlet (501) is arranged on the outer wall of the valve body (5) and can be communicated with the low-pressure annular groove (502), one side of the low-pressure oil passage (504) can be communicated with the low-pressure annular groove (502) or the external atmosphere, and the other side is communicated with the second valve (60) hole; The high-pressure annular groove (506) is formed between the second valve core (6) and the second valve (60) hole; the oil return hole (508) is arranged on the outer wall of the valve body (5) and is connected to the atmosphere; the high-pressure oil inlet (505) is arranged on the outer wall of the valve body (5) and is capable of communicating with the high-pressure annular groove (506); the high-pressure annular groove (506) is connected to the high-pressure oil hole (507); and the oil return annular groove (509) is capable of communicating with the oil return hole (508); When the first valve core (4) is in the first position, the low-pressure oil inlet (501), the low-pressure annular groove (502) and the low-pressure oil passage (504) are connected in sequence, and the second valve core (6) can be moved to the second position; When the second valve core (6) is in the second position, the high-pressure oil inlet (505), the high-pressure ring groove (506) and the high-pressure oil hole (507) are connected in sequence; When the first valve core (4) is in the third position, the low-pressure oil inlet (501) and the low-pressure annular groove (502) as well as the low-pressure annular groove (502) and the low-pressure oil passage (504) are blocked by the first valve core (4), the low-pressure oil passage (504) is connected to the external atmosphere, and the second valve core (6) can be moved to the fourth position; When the second valve core (6) is in the fourth position, the high-pressure oil inlet (505) and the high-pressure annular groove (506) are separated by the second valve core (6), and the high-pressure oil hole (507), the oil return annular groove (509), the oil return hole (508) and the external atmosphere are connected in sequence.

8. The single-piston hydraulic variable valve drive structure according to claim 7, characterized in that: The first valve (40) further comprises a first spring (1), an electromagnet component (2) and an armature (3); the armature (3) is connected to the first valve core (4), the armature (3) cooperates with the electromagnet component (2), and the first spring (1) is used to provide a force for the first valve core (4) to move away from the electromagnet component (2).

9. The single-piston hydraulic variable valve drive structure according to claim 7, characterized in that: The valve body (5) is provided with a mounting groove connected to the second valve (60) hole, and the second valve (60) also includes a second spring (7) installed in the mounting groove and connected to the second valve core (6), and the second spring (7) is used to provide a force for the second valve core (6) to approach the low-pressure oil channel (504).

10. The single-piston hydraulic variable valve drive structure according to claim 1, characterized in that: The valve assembly (C) comprises a valve rod, a valve spring (11) and a valve spring seat (12); the valve rod is telescopically connected to the valve spring seat (12) via the valve spring (11); and the valve rod abuts against the drive piston (9).

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