Valve lift conversion control mechanism and valvetrain system of engine

Abstract

A valve lift conversion control mechanism, comprising a hydraulic transmission device (105) provided with at least two device bodies, and a one-way valve (104), and an electromagnetic valve (102). The device bodies are communicated with each other by means of an oil path (154); the electromagnetic valve (102) can convey oil to the oil path (154) through the one-way valve (104); a second device body can be driven by downward pressing of a second rocker arm (205) to press the oil in the oil path (154) so as to increase the oil pressure; and a first device body can utilize the increased oil pressure in the oil path (154) to downwards press a first air valve (203) controlled by a first rocker arm (202). Further disclosed is a valvetrain system of an engine (101).

Description

Valve lift conversion control mechanism and engine valve distribution system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 25, 2023, with application number 202311077474.1 and invention name “Valve lift conversion control mechanism and engine valve system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of engine valve control, for example, to a valve lift conversion control mechanism and also to an engine valve distribution system. Background Art

[0003] The engine's valvetrain consists of rocker arms, valves, and a camshaft. The rocker arm has a rocker shaft in the middle, and its ends contact the valve and camshaft cams, respectively. During operation, the camshaft rotates, driving the rocker arm to swing around the rocker shaft. This swinging motion presses against the valve, opening it.

[0004] During engine operation, the valve lift often needs to be changed due to actual working conditions. For example, when the engine is running at low load, opening the exhaust valve early can discharge the high-temperature gas in the cylinder that has not yet pushed the piston to work, so as to heat the after-treatment, improve the after-treatment efficiency and reduce pollutant emissions. When internal exhaust gas recirculation is used during engine operation, an additional small cam needs to be added to the camshaft to control the exhaust valve to open again during the opening of the intake valve, so as to backflow the exhaust gas into the cylinder.

[0005] These additional changes in valve lift typically require a switching mechanism. For example, when the lift of the first valve needs to be changed, the first actuator, which is used to drive the first valve to its full normal lift, is first released. The second actuator then transmits the driving force to the first valve via the switching mechanism, allowing the first valve to achieve the lift provided by the second actuator. However, the normal lift provided by the first actuator to the first valve is lost and cannot be combined with the lift provided by the second actuator.

[0006] Therefore, how to provide a valve lift conversion control mechanism to enable the valve to make additional changes on the basis of normal lift is an urgent problem to be solved by those skilled in the art.

[0007] Summary of the Invention

[0008] The present application provides a valve lift conversion control mechanism, wherein a solenoid valve can deliver oil to the oil circuit of a hydraulic transmission device through a one-way valve. A second device body in the hydraulic transmission device can be driven downward by a second rocker arm to squeeze the oil in the oil circuit, increasing the oil pressure in the oil circuit and driving the first device body downward to press down on the first valve controlled by the first rocker arm, thereby transferring the valve lift controlled by the second rocker arm to the first valve controlled by the first rocker arm, thereby achieving valve lift conversion between different rocker arms of the valve train. Simultaneously, the valve lift conversion control mechanism does not affect the swing of the first rocker arm, allowing the lift provided to the first valve by the first rocker arm and the lift provided to the first valve by the second rocker arm via the hydraulic transmission device to be combined, resulting in additional changes to the first valve's normal lift. The present application also provides an engine valve train system, which utilizes the aforementioned valve lift conversion control mechanism to enable additional changes to the first valve's normal lift.

[0009] One embodiment provides a valve lift conversion control mechanism for an engine valve train system, comprising:

[0010] A hydraulic transmission device, the hydraulic transmission device comprising at least two device bodies, each of the device bodies being connected via an oil circuit;

[0011] a one-way valve and a solenoid valve, wherein the solenoid valve is capable of delivering oil to the oil circuit through the one-way valve;

[0012] Among them, in the hydraulic transmission device, the second device body can be driven by the downward pressure of the second rocker arm of the valve system to squeeze the oil in the oil circuit and increase the oil pressure, and the first device body can use the increased oil pressure in the oil circuit to press down the first valve controlled by the first rocker arm in the valve system.

[0013] In one embodiment, the valve lift conversion control mechanism further includes a reset device, and the reset device is used to drain the oil of the hydraulic transmission device.

[0014] In one embodiment, in the valve lift conversion control mechanism, the device body includes a housing and a plunger inserted into the housing; the plunger divides the interior space of the housing into an elastic member installation space and a hydraulic chamber; the hydraulic chambers of the first device body and the second device body are connected via the oil passage; the preload forces of the elastic members installed in the elastic member installation space of the first device body and the elastic member installation space of the second device body are different, and the preload force of the elastic member installed in the elastic member installation space of the first device body is greater;

[0015] Among them, the first plunger of the first device body is used to press down the first valve controlled by the first rocker arm under the action of the oil pressure in the hydraulic cavity in the device body; the second plunger of the second device body is driven downward by the second rocker arm to squeeze the oil in the hydraulic cavity in the device body.

[0016] In one embodiment, in the above-mentioned valve lift conversion control mechanism, the reset device includes a reset rod slidably inserted into the second housing of the second device body;

[0017] The second housing is provided with an oil drain passage communicating with the hydraulic chamber of the second device body; the reset lever can open and close the oil drain passage during movement.

[0018] In one embodiment, in the above-mentioned valve lift conversion control mechanism, the reset rod is connected to the second housing through a spring, and the spring provides a driving force to the reset rod to move in a direction of separating from the second housing so as to close the oil drain channel; the reset rod can be moved by being pressed downward by the second rocker arm and open the oil drain channel.

[0019] In one embodiment, in the above-mentioned valve lift conversion control mechanism, an annular groove is provided on the outer peripheral surface of the second plunger, and the second plunger is provided with a channel connecting the annular groove and the hydraulic chamber; the annular groove is always connected to the oil drain channel; the outer periphery of the reset rod is provided with a diameter-reducing annular groove, and the oil drain channel is opened when the diameter-reducing annular groove is aligned with the oil drain channel, and the oil drain channel is closed when the diameter-reducing annular groove is offset from the oil drain channel.

[0020] In one embodiment, in the valve lift conversion control mechanism, a dimension of the annular groove along the radial direction of the second plunger ranges from 0.05 mm to 2 mm.

[0021] In one embodiment, the valve lift conversion control mechanism further includes an oil storage valve, which is connected to the oil pipe between the solenoid valve and the one-way valve and is used to fill oil into the oil circuit.

[0022] One embodiment provides a valve distribution system of an engine, comprising a first rocker arm capable of swinging, a first cam for driving the first rocker arm to swing, a first valve opened by the first rocker arm, a second rocker arm capable of swinging, a second cam for driving the second rocker arm to swing, and a second valve opened by the second rocker arm; and also comprising a valve lift conversion control mechanism as described in any one of the above technical solutions.

[0023] In one embodiment, in the above-mentioned valve timing system, the second cam drives the second rocker arm to swing and then controls the second valve through a clearance compensation mechanism; and a small cam is provided on the outer peripheral surface of the second cam.

[0024] The present application provides a valve lift conversion control mechanism for an engine's valve train system, comprising a hydraulic transmission device and a solenoid valve; the hydraulic transmission device comprises at least two device bodies, each of which is connected via an oil circuit; the solenoid valve can deliver oil to the oil circuit via a one-way valve; wherein, in the hydraulic transmission device, the second device body can be driven by the downward pressure of the second rocker arm of the valve train system to squeeze the oil in the oil circuit and increase the oil pressure, and the first device body can use the increased oil pressure in the oil circuit to depress the first valve controlled by the first rocker arm of the valve train system.

[0025] In the aforementioned valve lift switching control mechanism, the solenoid valve can deliver oil to the oil circuit of the hydraulic transmission device via a one-way valve, filling the hydraulic transmission device with oil. The second device body in the hydraulic transmission device is driven by the downward pressure of the second rocker arm to squeeze the oil in the oil circuit, increasing the oil pressure in the oil circuit and driving the first device body to press down on the first valve controlled by the first rocker arm, thereby transferring the valve lift controlled by the second rocker arm to the first valve controlled by the first rocker arm, thereby achieving valve lift switching between different rocker arms in the valve train. Simultaneously, the valve lift switching control mechanism does not affect the swinging motion of the first rocker arm, allowing the lift provided to the first valve by the first rocker arm to be combined with the lift provided to the first valve by the second rocker arm via the hydraulic transmission device, thereby causing the first valve to undergo an additional change in lift beyond the normal lift.

[0026] In addition, the valve lift conversion control mechanism does not affect the swing of the second rocker arm, so that the second valve controlled by the second rocker arm can perform normal lift.

[0027] The present application also provides a valve distribution system of an engine, which applies the above-mentioned valve lift conversion control mechanism to enable the first valve to undergo additional changes on the basis of normal lift. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a control principle diagram of a lift conversion control mechanism provided in an embodiment of the present application;

[0029] FIG2 is a schematic structural diagram of a lift conversion control mechanism provided in an embodiment of the present application;

[0030] FIG3 is a schematic structural diagram of a second cam provided in an embodiment of the present application;

[0031] FIG4 is a schematic structural diagram of a first cam provided in an embodiment of the present application;

[0032] FIG5 is a schematic structural diagram of an embodiment of the present application in which the annular groove of the reset rod is staggered with the oil drain channel and the oil drain channel is closed;

[0033] FIG6 is a schematic structural diagram of an embodiment of the present application in which the annular groove of the reset lever is aligned with the oil drain channel and the oil drain channel is opened;

[0034] FIG7 is a schematic structural diagram of a valve train system according to an embodiment of the present application, in which the base circles of the first cam and the second cam are in contact with the corresponding rocker arms, and the hydraulic transmission device is filled with oil;

[0035] FIG8 is a schematic diagram of the hydraulic state when the second cam according to an embodiment of the present application operates to a small cam lift;

[0036] FIG9 is a diagram showing the relationship between the valve timing and valve lift during early exhaust valve opening and internal exhaust gas recirculation in the valve timing system provided by an embodiment of the present application;

[0037] FIG10 is a schematic diagram of the hydraulic state when the second cam according to an embodiment of the present application runs beyond the small cam lift and then continues to run to the main cam lift;

[0038] FIG11 is a schematic diagram of the second cam according to an embodiment of the present application running to the main cam lift and the first valve being reset after the hydraulic transmission device drains oil;

[0039] FIG12 is a schematic diagram of the second cam according to an embodiment of the present application when the main cam lift ends, the second rocker arm returns to its original position, and the hydraulic transmission device replenishes oil;

[0040] FIG13 is a schematic diagram of a solenoid valve controlling two oil circuits provided in an embodiment of the present application.

[0041] Among them, in Figures 1 to 13: engine 101; solenoid valve 102; oil storage valve 103; one-way valve 104; hydraulic transmission device 105; first spring 151; first plunger 152; first housing 153; oil circuit 154; second plunger 155; annular groove 1551; channel 1552; second spring 156; second housing 157; oil drain channel 1571; reset device 106; reset rod 161; reducing annular groove 1611; spring 162; first cam 201; first rocker arm 202; first valve 203; second cam 204; second rocker arm 205; clearance compensation mechanism 206; second valve 207. DETAILED DESCRIPTION

[0042] The embodiment of the present application discloses a valve lift conversion control mechanism, wherein the solenoid valve thereof can deliver oil to the oil circuit of the hydraulic transmission device through a one-way valve, and the second device body in the hydraulic transmission device can be driven by the downward pressure of the second rocker arm to squeeze the oil in the oil circuit, thereby increasing the oil pressure in the oil circuit and driving the first device body to press down the first valve controlled by the first rocker arm, thereby transferring the valve lift controlled by the second rocker arm to the first valve controlled by the first rocker arm, thereby realizing the valve lift conversion of different rocker arms of the valve timing mechanism; at the same time, the valve lift conversion control mechanism does not affect the swing of the first rocker arm, so that the lift provided by the first rocker arm to the first valve and the lift provided by the second rocker arm to the first valve through the hydraulic transmission device are combined, so that the first valve undergoes additional changes on the basis of normal lift. The embodiment of the present application also discloses an engine valve timing system, which uses the above-mentioned valve lift conversion control mechanism to enable the first valve to undergo additional changes on the basis of normal lift.

[0043] Please refer to Figures 1 to 13. An embodiment of the present application provides a valve lift conversion control mechanism for the valve train of an engine 101, including a hydraulic transmission device 105 and a solenoid valve 102; the hydraulic transmission device 105 includes at least two device bodies, each of which is connected through an oil circuit 154; the solenoid valve 102 can deliver oil to the oil circuit 154 through a one-way valve 104; wherein, in the hydraulic transmission device 105, the second device body can be driven by the downward pressure of the second rocker arm 205 of the valve train to squeeze the oil in the oil circuit 154 and increase the oil pressure; the first device body can use the increased oil pressure in the oil circuit 154 to press down the first valve 203 controlled by the first rocker arm 202 in the valve train.

[0044] In the aforementioned valve lift switching control mechanism, the solenoid valve 102 can deliver oil to the oil passage 154 of the hydraulic transmission device 105 via the check valve 104, filling the hydraulic transmission device 105 with oil. The second device body in the hydraulic transmission device 105 can be driven by the downward pressure of the second rocker arm 205 to squeeze the oil in the oil passage 154, increasing the oil pressure in the oil passage 154 and driving the first device body to press down on the first valve 203 controlled by the first rocker arm 202. This transfers the valve lift controlled by the second rocker arm 205 to the first valve 203 controlled by the first rocker arm 202, thereby achieving valve lift switching between different rocker arms in the valve train. Simultaneously, this valve lift switching control mechanism does not affect the swinging motion of the first rocker arm 202, allowing the lift provided by the first rocker arm 202 to the first valve 203 to be combined with the lift provided by the second rocker arm 205 to the first valve 203 via the hydraulic transmission device 105, thereby causing the first valve 203 to undergo an additional change in lift beyond the normal lift.

[0045] In addition, the valve lift conversion control mechanism does not affect the swing of the second rocker arm 205, so that the second valve 207 controlled by the second rocker arm 205 can perform normal lift.

[0046] The valve lift conversion control mechanism further includes a reset device 106 , which is used to drain the oil of the hydraulic transmission device 105 .

[0047] In the above scheme, the device body includes a housing and a plunger inserted into the housing (i.e., the first device body and the second device body include a housing and a plunger, respectively); the plunger divides the internal space of the housing into an elastic member installation space and a hydraulic chamber; the elastic member installation space is used to install the elastic member. The hydraulic chambers of the first and second device bodies are connected by an oil circuit 154. The preload forces of the elastic members installed in the elastic member installation spaces of the first and second device bodies are different, and the preload force of the elastic members installed in the elastic member installation space of the first device body is greater. Among them, the plunger of the first device body is the first plunger 152, which is used to press down the first valve 203 controlled by the first rocker arm 202 under the action of the oil pressure in the hydraulic chamber of the device body; the plunger of the second device body is the second plunger 155, which is driven downward by the second rocker arm 205 to squeeze the oil in the hydraulic chamber of the device body.

[0048] In one embodiment, the elastic member installed in the elastic member installation space of the first device body is a first spring 151, and the elastic member installed in the elastic member installation space of the second device body is a second spring 156. The outer shell of the first device body is a first shell 153, in which the hydraulic chamber is located at the top and the elastic member installation space is located at the bottom; the outer shell of the second device body is a second shell 157, in which the hydraulic chamber is located at the bottom and the elastic member installation space is located at the top.

[0049] 2 and 5 , the reset device 106 includes a reset rod 161 that can be slidably inserted into a second housing 157 of the second device body; the second housing 157 is provided with an oil drain channel 1571 that is connected to the hydraulic chamber of the second device body; the reset rod 161 can open and close the oil drain channel 1571 during movement.

[0050] The reset rod 161 is connected to the second housing 157 through a spring 162, and the spring 162 provides a driving force to the reset rod 161 to move in the direction of separating from the second housing 157 so that the oil drain channel 1571 is closed; the reset rod 161 can be moved and open the oil drain channel 1571 by being pressed down by the second rocker arm 205.

[0051] An annular groove 1551 is provided on the outer circumference of the second plunger 155, and the second plunger 155 is provided with a channel 1552 connecting the annular groove 1551 and the hydraulic chamber; the annular groove 1551 is always connected to the oil drain channel 1571; a reducing ring groove 1611 is provided on the outer circumference of the reset rod 161, and the oil drain channel 1571 is opened when the reducing ring groove 1611 and the oil drain channel 1571 are aligned, and the oil drain channel 1571 is closed when the reducing ring groove 1611 and the oil drain channel 1571 are offset.

[0052] In one embodiment, the annular groove 1551 has a radial dimension ranging from 0.05 mm to 2 mm along the radial direction of the second plunger 155 .

[0053] The valve lift conversion control mechanism also includes an oil accumulator valve 103, which is connected to the oil pipe between the solenoid valve 102 and the one-way valve 104 and is used to charge oil into the oil passage 154. The solenoid valve 102 is connected to an engine 101 for supplying oil to the solenoid valve 102. The oil supply pressure of the engine 101 is greater than the preload force of the elastic member installed in the elastic member installation space of the second device body, and less than the preload force of the elastic member installed in the elastic member installation space of the first device body.

[0054] In the aforementioned valve lift conversion control mechanism, the first rocker arm 202 is driven by the first cam 201, and the second rocker arm 205 is driven by the second cam 204. The lift of the first cam 201 and the lift of the second cam 204 have a preset phase angle relationship. The first cam 201 can drive the first rocker arm 202 to normally open and close the first valve 203. The second cam 204 can drive the second rocker arm 205 to control the normal opening and closing of the second valve 207 via the clearance compensation mechanism 206. Furthermore, the second cam 204 includes additional cam lift, which can be transmitted to the first valve 203 via the hydraulic transmission device 105, thus achieving the valve lift conversion function.

[0055] When the solenoid valve 102 is closed, the hydraulic transmission device 105 is not filled with oil, and valve lift switching will not occur. When the solenoid valve 102 is opened, the hydraulic transmission device 105 is filled with oil. Because the preload force of the first spring 151 is greater than the thrust of the oil pressure from the engine 101 on the first plunger 152, and the preload force of the second spring 156 is less than the thrust of the oil pressure from the engine 101 on the second plunger 155, a check valve 104 is installed between the oil passage 154 of the hydraulic transmission device 105 and the solenoid valve 102. When the second plunger 155 is pressed downward by the second rocker arm 205, high oil pressure is generated in the hydraulic transmission device 105. This high oil pressure overcomes the damping of the first spring 151, pushing the first plunger 152 downward, causing it to press the first valve 203 downward, achieving lift switching. An oil accumulator valve 103 is installed between the solenoid valve 102 and the check valve 104 to quickly replenish oil after the hydraulic transmission device 105 is reset.

[0056] During the movement of the second plunger 155, the annular groove 1551 always remains connected to the oil drain channel 1571. The opening and closing moments of the oil drain channel 1571 are completed by the second rocker arm 205 cooperating with the spring 162 to control the up and down movement of the reset rod 161. A diameter-reducing annular groove 1611 is provided on the reset rod 161; when the second rocker arm 205 drives the reset rod 161 to move downward to overcome the damping of the spring 162, the diameter-reducing annular groove 1611 can be connected to the oil drain channel 1571 for oil drain; when the driving force of the second rocker arm 205 gradually disappears, the spring 162 drives the reset rod 161 to move, so that the diameter-reducing annular groove 1611 is staggered with the oil drain channel 1571, and the large outer diameter position of the reset rod 161 except the diameter-reducing annular groove 1611 is aligned with the oil drain channel 1571, so that the oil drain channel 1571 is blocked and oil is prevented from leaking.

[0057] Please refer to Figure 7. When the solenoid valve 102 and the engine 101 are turned on, and the base circle position of the first cam 201 contacts the first rocker arm 202, and the base circle position of the second cam 204 contacts the second rocker arm 205, the oil circuit 154 of the hydraulic transmission device 105 is filled with oil, and the oil pressure pushing force acting on the second plunger 155 is greater than the preload force of the second spring 156, pushing the second plunger 155 upward to eliminate the gap between the second plunger 155 and the second rocker arm 205. However, the preload force of the first spring 151 is greater than the oil pressure pushing force acting on the first plunger 152, so the first plunger 152 will not press down the first valve 203 under the action of the oil pressure.

[0058] As shown in Figure 8 , when the second cam 204 reaches the additional cam lift position, the clearance compensation mechanism 206 between the second rocker arm 205 and the second valve 207 compensates for this portion of the lift, preventing the second valve 207 from opening. Simultaneously, because the clearance between the second plunger 155 and the second rocker arm 205 has been eliminated, the second plunger 155, driven by the second rocker arm 205, gradually moves downward, squeezing the oil in the oil passage 154 of the hydraulic transmission device 105. With the one-way valve 104 closed, the oil pressure within the hydraulic transmission device 105 gradually increases until the oil pressure drives the first plunger 152 downward, overcoming the preload of the first spring 151 and opening the first valve 203. This shift in lift can achieve the exhaust valve early opening function shown in Figure 9 , or other functions requiring a change in valve lift.

[0059] As shown in FIG10 , the second cam 204 continues to move beyond the additional cam lift to the main cam lift. At the beginning of the main cam lift, it is still in a lower position, which is equivalent to the additional cam lift. The second rocker arm 205 again controls the second plunger 155 to open the first valve 203 through hydraulic conversion, and starts the function of secondary opening of the exhaust valve as indicated in FIG9 .

[0060] As shown in Figure 11 , after the main cam lift of the second cam 204 is activated, the lift continues to increase. The second rocker arm 205 continues to press the second plunger 155 and the reset rod 161 downward. The reducing ring groove 1611 of the reset rod 161 aligns with the oil drain channel 1571, the hydraulic transmission device 105 drains oil, the first plunger 152 returns, and the first valve 203 follows the first plunger 152 back to close. This achieves the secondary opening of the first valve 203, and the lift gradually returns to closed, completing the secondary opening of the exhaust valve as shown in Figure 9 . Because the radial dimension of the reducing ring groove 1611 in the reset rod 161 is 0.05mm-2mm, the oil leakage rate can be controlled during the oil drain process, reducing the return rate of the first valve 203 and achieving a buffered return closure. At this time, the second rocker arm 205 continues to press downward, the clearance compensation mechanism 206 is fully compensated, and the second valve 207, driven by the second rocker arm 205, opens normally.

[0061] As shown in Figure 12, after the secondary cam 204 passes over the primary cam lift, causing the secondary rocker arm 205 to retract, the oil pressure within the hydraulic transmission device 105 decreases, and the reset rod 161 returns to the oil drain channel 1571, preventing oil from leaking. The solenoid valve 102 opens and replenishes oil into the hydraulic transmission device 105 through the check valve 104. Simultaneously, the oil within the oil accumulator valve 103, pushed by an elastic member (e.g., a spring) within the oil accumulator valve 103, rapidly replenishes the oil into the hydraulic transmission device 105, accelerating the replenishment process and preparing for the next cycle. The oil accumulator valve 103 is positioned between the solenoid valve 102 and the check valve 104, ensuring that the overall oil volume of the hydraulic transmission device 105 behind the check valve 104 is not altered, thus preventing any impact on lift transmission accuracy.

[0062] In actual applications, one solenoid valve 102 can branch out into two or more control oil circuits 154 to simultaneously control two or more identical hydraulic transmission devices 105, that is, one solenoid valve 102 can realize the lift conversion control of two or more cylinders, as shown in FIG13 .

[0063] An embodiment of the present application also provides a valve distribution system of an engine 101, including a first rocker arm 202 that can swing, a first cam 201 for driving the first rocker arm 202 to swing, a first valve 203 driven to open by the first rocker arm 202, a second rocker arm 205 that can swing, a second cam 204 for driving the second rocker arm 205 to swing, and a second valve 207 driven to open by the second rocker arm 205; and also includes a valve lift conversion control mechanism provided in the above embodiment.

[0064] The second cam 204 drives the second rocker arm 205 to swing, and then controls the second valve 207 through the clearance compensation mechanism 206; a small cam is provided on the outer peripheral surface of the second cam 204 for achieving additional cam lift.

[0065] The valve train system of engine 101 provided in this embodiment utilizes the aforementioned valve lift conversion control mechanism, enabling the first valve 203 to undergo additional lift changes beyond the normal lift. Of course, the valve train system provided in this embodiment also has other advantages associated with the valve lift conversion control mechanism provided in the aforementioned embodiments, which will not be further elaborated here.

[0066] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Claims

1. A valve lift conversion control mechanism, used in a valve distribution system of an engine (101), comprising: A hydraulic transmission device (105), the hydraulic transmission device (105) comprising at least two device bodies, the at least two device bodies being connected via an oil circuit (154); a one-way valve (104) and a solenoid valve (102), wherein the solenoid valve (102) can deliver oil to the oil circuit (154) through the one-way valve (104); Among them, in the hydraulic transmission device (105), the second device body can be driven by the downward pressure of the second rocker arm (205) of the valve system to squeeze the oil in the oil circuit (154) and increase the oil pressure, and the first device body can use the increased oil pressure in the oil circuit (154) to press down the first valve (203) controlled by the first rocker arm (202) in the valve system.

2. The valve lift conversion control mechanism according to claim 1 further comprises a reset device (106), wherein the reset device (106) is used to drain the oil of the hydraulic transmission device (105).

3. The valve lift switching control mechanism according to claim 2, wherein: The device body comprises a housing and a plunger inserted into the housing; the plunger divides the internal space of the housing into an elastic member installation space and a hydraulic chamber; the hydraulic chambers of the first device body and the second device body are connected via the oil circuit (154); the preload forces of the elastic members installed in the elastic member installation space of the first device body and the elastic member installation space of the second device body are different, and the preload force of the elastic member installed in the elastic member installation space of the first device body is greater; The first plunger (152) of the first device body is used to press down the first valve (203) controlled by the first rocker arm (202) under the action of the oil pressure in the hydraulic chamber of the device body; the second plunger (155) of the second device body is driven downward by the second rocker arm (205) to squeeze the oil in the hydraulic chamber of the device body.

4. The valve lift switching control mechanism according to claim 3, wherein: The reset device (106) comprises a reset rod (161) which can be slidably inserted into the second housing (157) of the second device body; The second housing (157) is provided with an oil drain channel (1571) communicating with the hydraulic chamber of the second device body; the reset rod (161) can open and close the oil drain channel (1571) during movement.

5. The valve lift switching control mechanism according to claim 4, wherein: The reset rod (161) is connected to the second housing (157) via a spring (162), and the spring (162) provides a driving force to the reset rod (161) to move in a direction away from the second housing (157) so as to close the oil drain channel (1571); the reset rod (161) can be moved and open the oil drain channel (1571) by being pressed downward by the second rocker arm (205).

6. The valve lift switching control mechanism according to claim 5, wherein: The outer circumferential surface of the second plunger (155) is provided with an annular groove (1551), and the second plunger (155) is provided with a channel (1552) connecting the annular groove (1551) and the hydraulic chamber; the annular groove (1551) is always connected with the oil leakage channel (1571); the outer circumference of the reset rod (161) is provided with a diameter-reducing annular groove (1611), and when the diameter-reducing annular groove (1611) is aligned with the oil leakage channel (1571), the oil leakage channel (1571) is opened, and when the diameter-reducing annular groove (1611) is offset from the oil leakage channel (1571), the oil leakage channel (1571) is closed.

7. The valve lift switching control mechanism according to claim 6, wherein: The dimension range of the annular groove (1551) along the radial direction of the second plunger (155) is 0.05 mm-2 mm.

8. The valve lift conversion control mechanism according to claim 1 further includes an oil storage valve (103), wherein the oil storage valve (103) is connected to the oil pipe between the solenoid valve (102) and the one-way valve (104) for filling oil into the oil circuit (154).

9. A valve train of an engine (101), comprising a first rocker arm (202) capable of swinging, a first cam (201) for driving the first rocker arm (202) to swing, a first valve (203) driven to open by the first rocker arm (202), a second rocker arm (205) capable of swinging, a second cam (204) for driving the second rocker arm (205) to swing, and a second valve (207) driven to open by the second rocker arm (205); and also comprising a valve lift conversion control mechanism as described in any one of claims 1 to 8.

10. The gas distribution system according to claim 9, wherein: The second cam (204) drives the second rocker arm (205) to swing and then controls the second valve (207) through a clearance compensation mechanism (206); a small cam is provided on the outer peripheral surface of the second cam (204).

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