Engine variable valve control device

Abstract

The present invention belongs to the technical field of automobile engines, and specifically relates to an engine variable valve control device, comprising a valve body and a controller. The valve body is provided with an oil inlet connector, a cam plunger, a valve plunger, and an oil return connector. A high-pressure oil chamber is provided within the valve body, and the oil inlet connector and the high-pressure oil chamber are connected via an oil inlet passage. A first passage connects the cam plunger mounting hole to the high-pressure oil chamber; a second passage connects the high-pressure oil chamber to the valve plunger mounting hole; an oil discharge passage is provided between the second passage and the first passage; a cam plunger outer sleeve connects to the first oil return passage; and a second oil return passage connects the valve plunger mounting hole to the oil return connector. The present invention adjusts the opening of the relief valve to change the oil volume in the valve plunger chamber, thereby changing the lift and duration of the valve. The device reacts sensitively to changes in engine operating conditions, meets the valve duration requirements of the engine operating conditions, and can flexibly switch between SI, SICI, and HCCI combustion modes.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobile engines, and in particular relates to an engine variable valve control device. Background Art

[0002] The development of new engine technologies is urgent. The Spark Induced Compression Ignition (SICI) combustion mode is a new combustion method between the spark induced compression ignition (SI) and homogeneous charge compression ignition (HCCI). SICI and HCCI are currently hot topics in new engine technologies. The main condition for the implementation of technologies such as SICI and HCCI is the thermal atmosphere in the cylinder. Variable valve technology can effectively change the atmosphere in the cylinder by changing the valve duration and timing, thereby achieving stable combustion modes such as SICI and HCCI. However, when the actual vehicle is running, the engine operating conditions change in real time. Therefore, the actual vehicle engine must be able to flexibly switch between SI, SICI and HCCI combustion modes, so a variable valve control device that can achieve valve profiles that meet multiple combustion modes is needed. Summary of the Invention

[0003] In order to solve the above technical problems and realize different valve profiles to meet the valve parameter requirements of engine combustion modes such as spark ignition, point-compression ignition, and compression ignition, the present invention provides an engine variable valve control device, including a valve body and a controller; installed on the outside of the cylinder head of the engine;

[0004] An oil inlet joint mounting hole is provided on one side end surface of the valve body, the oil inlet joint is mounted on the oil inlet joint mounting hole, and the oil inlet joint is connected to the hydraulic station through an oil pipe; a high-pressure oil chamber is provided in the valve body, and the oil inlet joint mounting hole and the high-pressure oil chamber are connected through an oil inlet channel;

[0005] A cam plunger mounting hole is provided on the upper end surface of the valve body, and the cam plunger mounting hole is connected to the high-pressure oil chamber through a first channel; the cam plunger sleeve is fixedly installed on the cam plunger mounting hole, the cam plunger sleeve is arranged in the cam plunger sleeve, and the cam plunger sleeve and the cam plunger sleeve are fixedly installed; the cam plunger is arranged in the cam plunger sleeve, and the cam plunger and the cam plunger sleeve are movably installed; a first oil return channel is provided on the upper end surface of the valve body, the inner end of the first oil return channel is connected to the first oil return through hole on the cam plunger sleeve, and the outer end of the first oil return channel is connected to the hydraulic station through an external joint and an oil pipe; a first stepper motor provided outside the valve body is connected to the control valve of the external joint, and the first stepper motor controls the switch of the external joint; the second oil return through hole on the cam plunger sleeve is connected to the first oil return through hole on the cam plunger sleeve; the third oil return through hole on the cam plunger is connected to the second oil return through hole on the cam plunger sleeve at a certain moment;

[0006] A valve plunger mounting hole is provided on one side end surface of the valve body, a valve plunger sleeve is fixedly mounted on the valve plunger mounting hole, the valve plunger is arranged in the valve plunger sleeve, and the valve plunger and the valve plunger sleeve are movably mounted together; the high-pressure oil chamber and the valve plunger mounting hole are connected through a second channel; a one-way valve is provided between the high-pressure oil chamber and the second channel, so that hydraulic oil can only flow from the high-pressure oil chamber to the valve plunger mounting hole;

[0007] An oil unloading channel is provided between the second channel and the first channel to accelerate the return speed of the hydraulic oil when the valve plunger returns;

[0008] A return oil joint mounting hole is provided on one side end face of the valve body, the return oil joint is mounted on the return oil joint mounting hole, and the return oil joint is connected to the hydraulic station through an oil pipe; the valve plunger mounting hole and the return oil joint mounting hole are connected through a second oil return channel; the fourth oil return through hole on the valve plunger sleeve is connected to the second oil return channel, and the valve plunger selectively blocks the fourth oil return through hole on the valve plunger sleeve; when the valve plunger is in the initial position, the valve plunger blocks the fourth oil return through hole on the valve plunger sleeve; when the valve plunger is squeezed outward and moves a certain distance, the valve plunger causes the fourth oil return through hole on the valve plunger sleeve to leak, and then the hydraulic oil circuit is connected to the second oil return channel;

[0009] A relief valve mounting hole is provided on one side end surface of the valve body, the relief valve is arranged in the relief valve mounting hole, and the second oil return channel flows through the flow control hole of the relief valve; a second stepper motor is provided on the outside of the valve body, the second stepper motor is connected to the screw of the relief valve, and the second stepper motor controls the flow opening of the relief valve, thereby controlling the flow of the second oil return channel;

[0010] The controller is electrically connected to the first stepper motor and the second stepper motor to control the operation of the first stepper motor and the second stepper motor.

[0011] A displacement sensor mounting hole is provided on one side end face of the valve body, and the displacement sensor is installed in the displacement sensor mounting hole; the displacement sensor mounting hole and the valve plunger mounting hole are arranged opposite to each other, and the displacement sensor mounting hole and the valve plunger mounting hole are connected through a monitoring through hole; the displacement sensor is electrically connected to the controller, and the displacement sensor monitors the valve profile in real time.

[0012] A mounting through hole is provided in the middle of the cam plunger sleeve for installing the cam plunger sleeve, and the cam plunger sleeve and the cam plunger sleeve have an interference fit; bolt through holes are provided on both sides of the mounting through hole, and the cam plunger sleeve is fixedly installed on the cam plunger mounting hole by bolts; the inner end of the first oil return through hole on the cam plunger sleeve is connected to the mounting through hole, and the outer end is connected to the first oil return channel.

[0013] The cam plunger sleeve is provided with a mounting through hole in the middle for mounting the cam plunger; bolt through holes are provided on both sides of the mounting through hole, corresponding to the threaded through holes on the cam plunger sleeve; the inner end of the second oil return through hole on the cam plunger sleeve is connected to the mounting through hole, and the outer end is connected to the first oil return through hole on the cam plunger sleeve; the outer wall of the cam plunger sleeve is provided with a ring groove for mounting a sealing ring.

[0014] The cam plunger is provided with an end cap at the upper end and a plunger cavity extending inward from the lower end, in which a return spring is provided; a third oil return hole is provided on the side wall of the plunger cavity, and the outer end of the third oil return hole is connected to the second oil return hole of the cam plunger sleeve; an annular groove is provided on the outer wall of the cam plunger for installing a sealing ring.

[0015] The middle of the valve plunger sleeve is provided with an installation through hole for installing the valve plunger, and the valve plunger and the valve plunger sleeve are ground together; the outer wall of the valve plunger sleeve is provided with an annular groove for installing a sealing ring.

[0016] The outer wall of the valve plunger is provided with a plurality of annular grooves, and the hydraulic oil is stored in the annular grooves to prevent the hydraulic oil from forming an oil seal with the valve plunger sleeve.

[0017] The oil inlet joint, the external joint and the oil return joint are respectively provided with a one-way valve.

[0018] The upper end of the cam plunger is connected to the cam; the outer end of the valve plunger is connected to the valve.

[0019] The working process of the engine variable valve control device of the present invention is as follows:

[0020] The present invention is designed for single-cylinder engines. It is mounted externally on the cylinder head and connected to the valve train to control the valves. The engine includes both intake and exhaust valves, so the aforementioned structure includes at least two sets within the valve body. The camshaft is mounted externally on the cylinder head via bearings. Its external connection end is belt-connected to a shaft extending from the engine crankshaft to ensure phase alignment between the valve train and the engine. The cam on the camshaft contacts the surface of the cam plunger.

[0021] When the engine is operating in normal ignition mode, the hydraulic station supplies oil to the oil inlet joint from the outside, and the high-pressure oil chamber is completely filled through the oil inlet channel.

[0022] When the engine is running, the camshaft rotates, the cam squeezes the cam plunger, and the hydraulic oil in the cam plunger's plunger cavity flows through the first channel into the high-pressure oil chamber. When the pressure in the high-pressure oil chamber is high enough, the hydraulic oil flows through the one-way valve in the lower high-pressure oil chamber into the second channel, squeezing the valve plunger in the valve plunger sleeve. When the hydraulic oil pressure is high enough, it overcomes the resistance of the valve spring and opens the valve, ensuring stable operation of the engine.

[0023] During the valve opening phase, after the valve plunger compresses the valve spring 2mm, the fifth oil return hole on the valve plunger, the fourth oil return hole on the valve plunger sleeve, the second oil return channel, and the oil return connector are connected in sequence. When the engine is operating under ignition conditions, the first stepper motor adjusts the control valve of the external connector, reducing the amount of oil returning to the hydraulic station from the external connector. At this time, most of the hydraulic oil flows back to the external hydraulic station through the fifth oil return hole on the valve plunger, the fourth oil return hole on the valve plunger sleeve, the second oil return channel, and the oil return connector. The second stepper motor controls the opening of the relief valve, thereby adjusting valve lift and duration. After the cam rotates past the cam lobe, the cam plunger begins to return due to the spring in the plunger cavity. When the valve plunger returns to block the fourth oil return hole, hydraulic oil flows only through the oil discharge channel from the external connector on the upper part of the valve body back to the hydraulic station, reducing the valve closing speed during the final 2mm, thereby ensuring engine life.

[0024] When the engine combustion mode switches to SICI or HCCI, a shorter valve duration is required. Therefore, the first stepper motor increases the opening of the control valve of the external connector. After the cam rotates past the cam lobe and the cam plunger returns to its original position, the vacuum in the plunger cavity causes the hydraulic oil in the valve plunger mounting hole to be drawn from the oil unloading channel into the plunger cavity. At this time, the hydraulic oil flows through the third oil return hole on the cam plunger, the second oil return hole on the cam plunger sleeve, and the first oil return hole on the cam plunger sleeve, and then through the first oil return channel and the external connector back to the hydraulic station. Adjusting the opening of the control valve of the external connector adjusts the return oil volume, thereby changing the valve lift and valve closing timing. This ensures that the valve closing timing is significantly advanced while maintaining minimal changes in the valve opening timing, increasing the negative valve overlap angle and enabling new combustion modes such as SICI and HCCI.

[0025] The control process of the present invention is as follows:

[0026] Obtain and determine whether the current state is an idle condition;

[0027] If it is idle condition at this time, the controller controls the first stepper motor to adjust the control valve of the external joint to close, and the valve profile is maintained at the result calibrated under the engine SI condition;

[0028] If the current working condition is not idle, then continue to obtain and determine whether the valve profile at this time is the optimal profile under the current working condition;

[0029] If the valve profile is not the optimal profile under the current working conditions, the second stepper motor controls the flow of the relief valve to adjust the valve lift and duration;

[0030] If the valve profile is the optimal profile under the current working conditions, then obtain and determine whether the water jacket temperature is greater than 30 degrees and the intake air temperature is greater than 25 degrees;

[0031] If the water jacket temperature is not greater than 30 degrees and the intake air temperature is not greater than 25 degrees, the valve parameters will maintain the current state to ensure stable engine operation.

[0032] If the water jacket temperature is greater than 30 degrees and the intake air temperature is greater than 25 degrees, continue to obtain and determine whether the speed and load at this time are within the SICI and HCCI operating conditions calibrated in the MAP;

[0033] If the operating condition is not within the SICI and HCCI operating ranges calibrated in the MAP, the second stepper motor is driven to adjust the opening of the relief valve, adjusting the valve lift and duration to be suitable for the current operating condition;

[0034] If the operating conditions at this time are within the SICI and HCCI operating conditions calibrated in the MAP, the first stepper motor is driven to open the control valve of the external connector, and the valve lift and closing timing are adjusted to ensure that the engine maintains operation in the SICI combustion mode.

[0035] The beneficial effects of the present invention are:

[0036] The continuously variable valve drive device employed in this invention is a stepper motor. This motor adjusts the opening of the relief valve, thereby varying the amount of oil in the valve plunger chamber and, in turn, the valve lift and duration. This device responds sensitively to changes in engine operating conditions and meets the valve duration requirements of these conditions. Compared to variable valve devices in existing engines, the variable valve control device described in this invention can achieve a variety of valve profiles suitable for different combustion modes, enabling flexible switching between SI, SICI, and HCCI combustion modes, adapting to a wide range of engine operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the overall cross-sectional structure of the valve body of the present invention;

[0038] Figure 2 It is a front view structural diagram of an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of a top view of the structure of an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the right side structure of an embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the CC cross-sectional structure of an embodiment of the present invention;

[0042] Figure 6 This is a schematic cross-sectional view of the DD embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of the cam plunger housing and its cross-sectional structure of the present invention;

[0044] Figure 8 This is a schematic diagram of the cam plunger sleeve structure of the present invention;

[0045] Figure 9 It is a cross-sectional schematic diagram of the cam plunger housing, cam plunger sleeve and cam plunger assembly structure of the present invention;

[0046] Figure 10 It is a cross-sectional schematic diagram of the assembly structure of the valve plunger and valve plunger sleeve of the present invention;

[0047] Figure 11 The valve profiles of the present invention under different combustion modes;

[0048] 1. Upper valve body, 2. Lower valve body, 3. Oil inlet connector, 4. Upper high-pressure oil chamber, 5. Oil inlet channel, 6. Cam plunger mounting hole, 7. First channel, 8. Cam plunger sleeve, 801. First oil return hole, 802. Cam plunger sleeve mounting hole, 9. Cam plunger sleeve, 901. Second oil return hole, 902. Cam plunger mounting hole, 903. Ring groove, 10. Cam plunger, 1001. Third oil return hole, 1002. Plunger cavity, 1003, annular groove, 11, first oil return channel, 12, lower high-pressure oil chamber, 13, valve plunger mounting hole, 14, valve plunger sleeve, 1401, fourth oil return through hole, 1402, valve plunger mounting through hole, 1403, annular groove, 15, valve plunger, 1501, annular groove, 16, second channel, 17, oil unloading channel, 18, oil return joint, 19, second oil return channel, 20, overflow valve, 21, displacement sensor, 22, monitoring through hole. DETAILED DESCRIPTION

[0049] See Figure 1-6 As shown, the present invention provides an engine variable valve control device, including a valve body and a controller; in order to facilitate punching and assembly, the valve body is divided into an upper valve body 1 and a lower valve body 2; the upper valve body 1 and the lower valve body 2 are fastened together by bolts and installed on the outside of the cylinder head of the engine;

[0050] In this embodiment, an oil inlet joint mounting hole is provided on the front end surface of the upper valve body 1, and an oil inlet joint 3 is mounted on the oil inlet joint mounting hole. The oil inlet joint 3 is connected to the hydraulic station via an oil pipe. An upper high-pressure oil chamber 4 is provided on the upper valve body 1. The upper high-pressure oil chamber 4 is located on the end surface where the upper valve body 1 and the lower valve body 2 meet. The oil inlet joint mounting hole and the upper high-pressure oil chamber 4 are connected via an oil inlet passage 5.

[0051] A cam plunger mounting hole 6 is provided on the upper end surface of the upper valve body 1, and the cam plunger mounting hole 6 is communicated with the upper high-pressure oil chamber 4 through a first channel 7; a cam plunger sleeve 8 is fixedly mounted on the cam plunger mounting hole 6, a cam plunger sleeve 9 is arranged in the cam plunger sleeve 8, and the cam plunger sleeve 9 is fixedly mounted with the cam plunger sleeve 8; a cam plunger 10 is arranged in the cam plunger sleeve 9, and the cam plunger 10 is movably mounted with the cam plunger sleeve 9; a first oil return channel 11 is provided on the upper end surface of the upper valve body 1, and the first oil return channel 11 The inner end of the cam body 1 is connected to the first oil return hole 801 on the cam plunger housing 8, and the outer end of the first oil return channel 11 is connected to the hydraulic station via an external joint and an oil pipe. The first stepper motor provided on the outside of the upper valve body 1 is connected to the control valve of the external joint, and the first stepper motor controls the opening and closing of the external joint. The second oil return hole 901 on the cam plunger housing 9 is connected to the first oil return hole 801 on the cam plunger housing 8. The third oil return hole 1001 on the cam plunger 10 is connected to the second oil return hole 901 on the cam plunger housing 9 at a certain moment.

[0052] The lower valve body 2 is provided with a lower high-pressure oil chamber 12, which is provided on the end surface where the lower valve body 2 and the upper valve body 1 meet. The upper high-pressure oil chamber 4 is sealed and connected with the lower high-pressure oil chamber 12 to form a high-pressure oil chamber as a whole.

[0053] A valve plunger mounting hole 13 is provided on the rear end surface of the lower valve body 2. A valve plunger sleeve 14 is fixedly mounted on the valve plunger mounting hole 13. A valve plunger 15 is disposed within the valve plunger sleeve 14. The valve plunger 15 and the valve plunger sleeve 14 are movably mounted in cooperation. The lower high-pressure oil chamber 12 is connected to the valve plunger mounting hole 13 via a second passage 16. A one-way valve is provided between the lower high-pressure oil chamber 12 and the second passage 16, so that hydraulic oil can only flow from the lower high-pressure oil chamber 12 to the valve plunger mounting hole 13.

[0054] An oil unloading channel 17 is provided between the second channel 16 and the first channel 7 to accelerate the return speed of the hydraulic oil when the valve plunger 15 returns;

[0055] The left and right end surfaces of the lower valve body 2 are respectively provided with return oil joint mounting holes, and the return oil joint 18 is installed on the return oil joint mounting holes. The return oil joint 18 is connected to the hydraulic station through an oil pipe; the valve plunger mounting hole 13 and the return oil joint mounting hole are connected through the second oil return channel 19; the fourth oil return through hole 1401 on the valve plunger sleeve 14 is connected to the second oil return channel 19; when the valve plunger 15 is in the initial position, the valve plunger 15 blocks the fourth oil return through hole 1401 on the valve plunger sleeve 14; when the valve plunger 15 is squeezed outward and moved a certain distance, the valve plunger 15 does not block the fourth oil return through hole 1401 on the valve plunger sleeve 14, thereby allowing the hydraulic oil circuit to communicate with the second oil return channel 19;

[0056] A relief valve mounting hole is provided on one side end surface of the lower valve body 2. The relief valve 20 is disposed within the relief valve mounting hole. The second oil return passage 19 flows through the flow control hole of the relief valve 20. A second stepper motor is provided on the outside of the lower valve body 2. The second stepper motor is connected to the screw of the relief valve 20. The second stepper motor controls the flow opening of the relief valve 20, thereby controlling the flow rate of the second oil return passage 19.

[0057] The controller is electrically connected to the first stepper motor and the second stepper motor to control the operation of the first stepper motor and the second stepper motor.

[0058] A displacement sensor mounting hole is also provided on the front end face of the lower valve body 2, and a displacement sensor 21 is installed in the displacement sensor mounting hole; the displacement sensor mounting hole is arranged opposite to the valve plunger mounting hole 13, and the displacement sensor mounting hole and the valve plunger mounting hole 13 are connected through a monitoring through hole 22; the displacement sensor 21 is electrically connected to the controller, and the displacement sensor 21 monitors the valve profile in real time.

[0059] See Figure 7-10 As shown, a cam plunger sleeve mounting through hole 802 is provided in the middle of the cam plunger sleeve 8 for mounting the cam plunger sleeve 9, and the cam plunger sleeve 9 is interference fit with the cam plunger sleeve 8; bolt through holes are provided on both sides of the mounting through hole, and the cam plunger sleeve 8 is fixedly mounted on the cam plunger mounting hole 6 by bolts; the inner end of the first oil return through hole 801 on the cam plunger sleeve 8 is connected to the mounting through hole, and the outer end is connected to the first oil return channel 11.

[0060] A cam plunger mounting through hole 902 is provided in the middle of the cam plunger sleeve 9 for mounting the cam plunger 10; bolt through holes are provided on both sides of the mounting through hole, corresponding to the threaded through holes on the cam plunger sleeve 8; the inner end of the second oil return through hole 901 on the cam plunger sleeve 9 is connected to the cam plunger mounting through hole 902, and the outer end is connected to the first oil return through hole 801 on the cam plunger sleeve 8; the outer wall of the cam plunger sleeve 9 is provided with an annular groove 903 for mounting a sealing ring.

[0061] The cam plunger 10 is provided with an end cap at the upper end and a plunger cavity 1002 extending inward from the lower end, in which a return spring is provided; a third oil return hole 1001 is provided on the side wall of the plunger cavity 1002, and the outer end of the third oil return hole 1001 is connected to the second oil return hole 901 of the cam plunger sleeve 9; an annular groove 1003 is provided on the outer wall of the cam plunger 10 for installing a sealing ring.

[0062] The valve plunger sleeve 14 has a valve plunger mounting through hole 1402 in the middle thereof for mounting the valve plunger 15 , which is ground into engagement with the valve plunger sleeve 14 ; an annular groove 1403 is provided on the outer wall of the valve plunger sleeve 14 for mounting a sealing ring.

[0063] The outer wall of the valve plunger 15 is provided with a plurality of annular grooves 1501 , into which the hydraulic oil is stored to prevent the hydraulic oil from forming an oil seal with the valve plunger sleeve 14 .

[0064] The oil inlet joint 3, the external joint and the oil return joint 18 are respectively provided with a one-way valve.

[0065] The upper end of the cam plunger 10 is connected to the cam; the outer end of the valve plunger 15 is connected to the valve.

[0066] The working process of the engine variable valve control device of the present invention is as follows:

[0067] This invention primarily focuses on developing a valve control mechanism suitable for multiple combustion modes, capable of switching valve profiles between different combustion modes to match the current combustion mode. Therefore, during engine operation, based on MAP calibration results, the valves are adjusted to a profile suitable for SICI combustion when the engine speed, load, and excess air ratio are within the SICI combustion mode range.

[0068] The present invention is designed for single-cylinder engines. It is mounted externally on the engine's cylinder head and connected to the valves to control them. Single-cylinder engines have two working chambers, so the aforementioned structure includes at least two groups within the valve body. The camshaft is mounted externally on the engine's cylinder head via bearings, and the cam on the camshaft contacts the surface of the cam plunger 10.

[0069] When the engine operates in the normal ignition mode, oil is supplied from the hydraulic station to the oil inlet connector 3 and the high-pressure oil chamber is completely filled through the oil inlet channel 5 .

[0070] When the engine is operating, the camshaft rotates, the cam squeezes the cam plunger 10, and the hydraulic oil in the plunger cavity 1002 of the cam plunger 10 flows through the first passage into the high-pressure oil chamber. When the pressure in the high-pressure oil chamber reaches a sufficient level, the hydraulic oil flows through the one-way valve in the lower high-pressure oil chamber 12 and enters the second passage 16, squeezing the valve plunger 15 in the valve plunger sleeve 14. When the hydraulic oil pressure is high enough, it overcomes the resistance of the valve spring, causing the valve to open, ensuring stable engine operation.

[0071] During the valve opening phase, after the valve plunger 15 squeezes the valve spring by 2mm, oil leaks out of the fourth oil return hole 1401 on the valve plunger sleeve 14. This connects the fourth oil return hole 1401, the second oil return channel 19, and the oil return connector 18 in sequence. When the engine is operating under ignition conditions, the first stepper motor adjusts the control valve of the external connector, reducing the amount of oil returning to the hydraulic station from the external connector. Most of the hydraulic oil now flows back to the external hydraulic station through the fourth oil return hole 1401 on the valve plunger sleeve 14, the second oil return channel 19, and the oil return connector 18. Driving the second stepper motor to adjust the opening of the relief valve 20 can adjust the valve lift and duration. After the cam rotates past the convex tip, the cam plunger 10 begins to reset due to the spring in the plunger cavity 1002. When the valve plunger 15 returns to block the fourth oil return hole 1401, the hydraulic oil only flows back to the hydraulic station from the external joint on the upper part of the valve body, reducing the closing speed of the valve in the last 2mm and ensuring the life of the engine.

[0072] When the engine combustion mode is switched to SICI or HCCI, a shorter valve duration is required. Therefore, the first stepper motor increases the opening of the control valve of the external connector. After the cam rotates past the cam tip and the cam plunger 10 returns to its original position, the vacuum force in the plunger cavity 1002 causes the hydraulic oil in the valve plunger mounting hole 13 to be drawn into the plunger cavity 1002 from the oil unloading channel 17. At this time, the hydraulic oil flows through the third oil return hole 1001 on the cam plunger 10, the second oil return hole 901 on the cam plunger sleeve 9, and the first oil return hole 801 on the cam plunger outer sleeve 8, and then flows back to the hydraulic station through the first oil return channel 11 and the external connector. Adjusting the opening of the control valve of the external connector can adjust the return oil volume, thereby changing the valve lift and valve closing time. This can ensure that the valve closing time is significantly advanced while the valve opening time does not change much, increasing the negative valve overlap angle and realizing new combustion modes such as SICI and HCCI.

[0073] Combine Figure 11 As shown, the control process of the present invention is as follows:

[0074] Obtain and determine whether the current state is an idle condition;

[0075] If it is idle condition at this time, the controller controls the first stepper motor to adjust the control valve of the external joint to close, and the valve profile is maintained at the result calibrated under the engine SI condition;

[0076] If the current working condition is not idle, then continue to obtain and determine whether the valve profile at this time is the optimal profile under the current working condition;

[0077] If the valve profile is not the optimal profile under the current working conditions, the second stepper motor controls the flow of the relief valve 20 to adjust the valve lift and duration;

[0078] If the valve profile is the optimal profile under the current working conditions, then obtain and determine whether the water jacket temperature is greater than 30 degrees and the intake air temperature is greater than 25 degrees;

[0079] If the water jacket temperature is not greater than 30 degrees and the intake air temperature is not greater than 25 degrees, the valve parameters will maintain the current state to ensure stable engine operation.

[0080] If the water jacket temperature is greater than 30 degrees and the intake air temperature is greater than 25 degrees, continue to obtain and determine whether the speed and load at this time are within the SICI and HCCI operating conditions calibrated in the MAP;

[0081] If the operating condition is not within the SICI and HCCI operating ranges calibrated in the MAP, the second stepper motor is driven to adjust the opening of the relief valve 20 to adjust the valve lift and duration to be suitable for the current operating condition;

[0082] If the operating conditions at this time are within the SICI and HCCI operating conditions calibrated in the MAP, the first stepper motor is driven to open the control valve of the external connector, and the valve lift and closing timing are adjusted to ensure that the engine maintains operation in the SICI combustion mode.

Claims

1. An engine variable valve control device, characterized in that: It includes a valve body and a controller. An oil inlet joint mounting hole is provided on one side end surface of the valve body. The oil inlet joint is mounted on the oil inlet joint mounting hole. The oil inlet joint is connected to the hydraulic station through an oil pipe. A high-pressure oil chamber is provided in the valve body. The oil inlet joint mounting hole and the high-pressure oil chamber are connected through an oil inlet channel. A cam plunger mounting hole is provided on the upper end surface of the valve body, and the cam plunger mounting hole is connected to the high-pressure oil chamber through a first channel; the cam plunger sleeve is fixedly installed on the cam plunger mounting hole, the cam plunger sleeve is arranged in the cam plunger sleeve, and the cam plunger sleeve and the cam plunger sleeve are fixedly installed; the cam plunger is arranged in the cam plunger sleeve, and the cam plunger and the cam plunger sleeve are movably installed; a first oil return channel is provided on the upper end surface of the valve body, the inner end of the first oil return channel is connected to the first oil return through hole on the cam plunger sleeve, and the outer end of the first oil return channel is connected to the hydraulic station through an external joint and an oil pipe; a first stepper motor provided outside the valve body is connected to the control valve of the external joint, and the first stepper motor controls the switch of the external joint; the second oil return through hole on the cam plunger sleeve is connected to the first oil return through hole on the cam plunger sleeve; the third oil return through hole on the cam plunger is connected to the second oil return through hole on the cam plunger sleeve at a certain moment; A valve plunger mounting hole is provided on one side end surface of the valve body, a valve plunger sleeve is fixedly mounted on the valve plunger mounting hole, the valve plunger is arranged in the valve plunger sleeve, and the valve plunger and the valve plunger sleeve are movably mounted together; the high-pressure oil chamber and the valve plunger mounting hole are connected through a second channel; a one-way valve is provided between the high-pressure oil chamber and the second channel, so that hydraulic oil can only flow from the high-pressure oil chamber to the valve plunger mounting hole; An oil unloading channel is provided between the second channel and the first channel to accelerate the return speed of the hydraulic oil when the valve plunger returns; A return oil joint mounting hole is provided on one side end face of the valve body, the return oil joint is mounted on the return oil joint mounting hole, and the return oil joint is connected to the hydraulic station through an oil pipe; the valve plunger mounting hole and the return oil joint mounting hole are connected through a second oil return channel; the fourth oil return through hole on the valve plunger sleeve is connected to the second oil return channel, and the valve plunger selectively blocks the fourth oil return through hole on the valve plunger sleeve; when the valve plunger is in the initial position, the valve plunger blocks the fourth oil return through hole on the valve plunger sleeve; when the valve plunger is squeezed outward and moves a certain distance, the valve plunger causes the fourth oil return through hole on the valve plunger sleeve to leak, and then the hydraulic oil circuit is connected to the second oil return channel; A relief valve mounting hole is provided on one side end surface of the valve body, the relief valve is arranged in the relief valve mounting hole, and the second oil return channel flows through the flow control hole of the relief valve; a second stepper motor is provided on the outside of the valve body, the second stepper motor is connected to the screw of the relief valve, and the second stepper motor controls the flow opening of the relief valve, thereby controlling the flow of the second oil return channel; The controller is electrically connected to the first stepper motor and the second stepper motor to control the operation of the first stepper motor and the second stepper motor.

2. The engine variable valve control device according to claim 1, characterized in that: A displacement sensor mounting hole is provided on one side end face of the valve body, and the displacement sensor is installed in the displacement sensor mounting hole; the displacement sensor mounting hole and the valve plunger mounting hole are arranged opposite to each other, and the displacement sensor mounting hole and the valve plunger mounting hole are connected through a monitoring through hole; the displacement sensor is electrically connected to the controller, and the displacement sensor monitors the valve profile in real time.

3. The engine variable valve control device according to claim 1, characterized in that: A mounting through hole is provided in the middle of the cam plunger sleeve for installing the cam plunger sleeve, and the cam plunger sleeve and the cam plunger sleeve have an interference fit; bolt through holes are provided on both sides of the mounting through hole, and the cam plunger sleeve is fixedly installed on the cam plunger mounting hole by bolts; the inner end of the first oil return through hole on the cam plunger sleeve is connected to the mounting through hole, and the outer end is connected to the first oil return channel.

4. The engine variable valve control device according to claim 1, characterized in that: The cam plunger sleeve is provided with a mounting through hole in the middle for mounting the cam plunger; bolt through holes are provided on both sides of the mounting through hole, corresponding to the threaded through holes on the cam plunger sleeve; the inner end of the second oil return through hole on the cam plunger sleeve is connected to the mounting through hole, and the outer end is connected to the first oil return through hole on the cam plunger sleeve; the outer wall of the cam plunger sleeve is provided with a ring groove for mounting a sealing ring.

5. The engine variable valve control device according to claim 1, characterized in that: The cam plunger is provided with an end cap at the upper end and a plunger cavity extending inward from the lower end, in which a return spring is provided; a third oil return hole is provided on the side wall of the plunger cavity, and the outer end of the third oil return hole is connected to the second oil return hole of the cam plunger sleeve; an annular groove is provided on the outer wall of the cam plunger for installing a sealing ring.

6. The engine variable valve control device according to claim 1, characterized in that: The middle of the valve plunger sleeve is provided with an installation through hole for installing the valve plunger, and the valve plunger and the valve plunger sleeve are ground together; the outer wall of the valve plunger sleeve is provided with an annular groove for installing a sealing ring.

7. The engine variable valve control device according to claim 1, characterized in that: The outer wall of the valve plunger is provided with a plurality of annular grooves.

8. The engine variable valve control device according to claim 1, characterized in that: The oil inlet joint, the external joint and the oil return joint are respectively provided with a one-way valve.

9. The control process of the engine variable valve control device according to claim 1 is as follows: Obtain and determine whether the current state is an idle condition; If it is idle condition at this time, the controller controls the first stepper motor to adjust the control valve of the external joint to close, and the valve profile is maintained at the result calibrated under the engine SI condition; If the current working condition is not idle, then continue to obtain and determine whether the valve profile at this time is the optimal profile under the current working condition; If the valve profile is not the optimal profile under the current working conditions, the second stepper motor controls the flow of the relief valve to adjust the valve lift and duration; If the valve profile is the optimal profile under the current working conditions, then obtain and determine whether the water jacket temperature is greater than 30 degrees and the intake air temperature is greater than 25 degrees; If the water jacket temperature is not greater than 30 degrees and the intake air temperature is not greater than 25 degrees, the valve parameters will maintain the current state to ensure stable engine operation. If the water jacket temperature is greater than 30 degrees and the intake air temperature is greater than 25 degrees, continue to obtain and determine whether the speed and load at this time are within the SICI and HCCI operating conditions calibrated in the MAP; If the operating condition is not within the SICI and HCCI operating ranges calibrated in the MAP, the second stepper motor is driven to adjust the opening of the relief valve, adjusting the valve lift and duration to be suitable for the current operating condition; If the operating conditions at this time are within the SICI and HCCI operating conditions calibrated in the MAP, the first stepper motor is driven to open the control valve of the external connector, and the valve lift and closing timing are adjusted to ensure that the engine maintains operation in the SICI combustion mode.

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