Variable valve control device of engine

Abstract

The invention belongs to the technical field of automobile engines, and particularly relates to an engine variable valve control device which comprises a valve body and a controller. An oil inlet connector, a cam plunger, an air valve plunger and an oil return connector are arranged on the valve body, a high-pressure oil cavity is formed in the valve body, and the oil inlet connector is communicated with the high-pressure oil cavity through an oil inlet channel. The cam plunger mounting hole is communicated with the high-pressure oil cavity through a first channel; the high-pressure oil cavity is communicated with the air valve plunger mounting hole through a second channel; an oil discharge channel is arranged between the second channel and the first channel; the cam plunger outer sleeve is communicated with the first oil return channel; the air valve plunger mounting hole is communicated with the oil return joint through a second oil return channel; the oil quantity in the air valve plunger cavity is changed by adjusting the opening degree of the overflow valve, and then the lift and the duration of the air valve are changed. And the change response to the engine working condition is sensitive, the requirement of the engine working condition for the valve duration is met, and flexible switching among the SI combustion mode, the SICI combustion mode and the HCCI combustion mode can be achieved.

Description

Technical Field

[0001] The 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. Spark Induced Compression Ignition (SICI) combustion mode is a new combustion mode between ignition combustion (SI) and homogeneous charge compression ignition combustion (HCCI). SICI and HCCI are hot topics in current engine technologies. The main conditions for the realization of technologies such as SICI and HCCI are 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 requirements of valve parameters for combustion modes such as engine 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 outside 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 in cooperation; the cam plunger is arranged in the cam plunger sleeve, and the cam plunger and the cam plunger sleeve are movably installed in cooperation; 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 arranged outside the valve body is connected to a 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; the high-pressure oil chamber is connected to the valve plunger mounting hole through a second channel; a one-way valve is provided between the high-pressure oil chamber and the second channel, and the 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, which is used to speed up the return speed of the hydraulic oil when the valve plunger returns;

[0008] An oil return joint mounting hole is provided on one side end face of the valve body, the oil return joint is mounted on the oil return joint mounting hole, and the oil return joint is connected to the hydraulic station through an oil pipe; the valve plunger mounting hole and the oil return 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 outside 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 mounting 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 mounted 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] A mounting through hole is provided in the middle of the cam plunger sleeve 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; an annular groove is provided on the outer wall of the cam plunger sleeve for mounting a sealing ring.

[0014] The cam plunger is provided with an end cap at the upper end, and a plunger cavity is extended inward at 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 is ground and matched with the valve plunger sleeve; 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 formation of 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 a single cylinder engine, installed outside the cylinder head of the engine, and connected to the valve to control the valve. The engine includes an intake valve and an exhaust valve, so the above structure includes at least two groups in the valve body. The camshaft is installed outside the cylinder head of the engine through a bearing, and the external connection end is connected to the shaft belt extending from the engine crankshaft end to ensure that the valve mechanism and the engine are in phase. 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 working, the camshaft rotates, the cam squeezes the cam plunger, and the hydraulic oil in the plunger cavity of the cam plunger enters the high-pressure oil chamber through the first channel. When the pressure in the high-pressure oil chamber is high enough, the hydraulic oil enters the second channel through the one-way valve of the lower high-pressure oil chamber, 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 to open the valve, ensuring the stable operation of the engine.

[0023] In the valve opening stage, after the valve plunger squeezes 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 joint are connected in sequence; when the engine is running under the ignition condition, the first stepper motor adjusts the control valve of the external joint to reduce the amount of oil returning to the hydraulic station from the external joint at this time. 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 joint. The second stepper motor is driven to adjust the opening of the overflow valve, which can adjust the valve lift and duration. After the cam turns over the convex tip, the cam plunger begins to reset due to the spring in the plunger cavity. When the valve plunger returns to block the fourth oil return hole, the hydraulic oil only flows back to the hydraulic station from the external joint on the upper part of the valve body through the oil unloading channel, reducing the closing speed of the valve in the last 2mm, ensuring the life of the engine.

[0024] When the engine combustion mode is converted 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 convex tip, during the return of the cam plunger, the vacuum suction in the plunger cavity causes the hydraulic oil in the valve plunger mounting hole to be sucked into the plunger cavity from the oil unloading channel. 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 flows back to the hydraulic station through the first oil return channel and the external connector. By adjusting the opening of the control valve of the external connector, the return oil volume can be adjusted, thereby changing the valve lift and valve closing time, which can ensure that the valve closing time is greatly advanced under the premise that the valve opening time does not change much, increase the negative valve overlap angle, and realize 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 condition, 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 condition, 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 operation of the engine;

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

[0033] If the working condition at this time is not within the SICI and HCCI working condition range calibrated in the MAP, the second stepper motor is driven to adjust the opening of the relief valve, and the valve lift and duration are adjusted to be suitable for the current working condition;

[0034] If the operating condition is within the SICI and HCCI operating range calibrated in the MAP, the first stepper motor is driven to open the control valve of the external connector, adjust the valve lift and closing time, and ensure that the engine maintains working in the SICI combustion mode.

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

[0036] The driving device for continuously changing the valve used in the present invention is a stepper motor, which adjusts the opening of the overflow valve to change the amount of oil in the valve plunger cavity, thereby changing the lift and duration of the valve. It is sensitive to changes in engine operating conditions and meets the requirements of the engine operating conditions for valve duration. Compared with the variable valve device of the finished engine, the variable valve control device of the present invention can realize a variety of valve profiles suitable for different combustion modes. The engine can flexibly switch between SI, SICI and HCCI combustion modes, and is suitable for various operating conditions of the engine. 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 schematic diagram of an embodiment of the present invention;

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

[0040] Figure 4 It is a right view structural schematic diagram 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 structure of the embodiment DD of the present invention;

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

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

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

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

[0047] Fig.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 through hole, 802. Cam plunger sleeve mounting through hole, 9. Cam plunger sleeve, 901. Second oil return through hole, 902. Cam plunger mounting through hole, 903. Ring groove, 10. Cam plunger, 1001. Third oil return through 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 also 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 and connected by bolts and installed outside 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 the oil inlet joint 3 is installed on the oil inlet joint mounting hole, and the oil inlet joint 3 is connected to the hydraulic station through an oil pipe; an upper high-pressure oil chamber 4 is provided on the upper valve body 1, and 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 are connected; the oil inlet joint mounting hole and the upper high-pressure oil chamber 4 are connected through an oil inlet channel 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 installed 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 installed 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 installed 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 sleeve 8, and the outer end of the first oil return channel 11 is connected to the hydraulic station through an external joint and an oil pipe; the first stepper motor arranged outside the upper valve body 1 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 hole 901 on the cam plunger sleeve 9 is connected to the first oil return hole 801 on the cam plunger sleeve 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 sleeve 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, and the upper high-pressure oil chamber 4 is sealed and matched 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 arranged in the valve plunger sleeve 14, and the valve plunger 15 and the valve plunger sleeve 14 are movably mounted; the lower high-pressure oil chamber 12 is connected to the valve plunger mounting hole 13 through a second channel 16; a one-way valve is provided between the lower high-pressure oil chamber 12 and the second channel 16, and the 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 to its original position;

[0055] The left and right side end surfaces of the lower valve body 2 are respectively provided with return oil joint mounting holes, and the return oil joint 18 is mounted on the return oil joint mounting holes, and the return oil joint 18 is connected to the hydraulic station through an oil pipe; the valve plunger mounting hole 13 is connected to the return oil joint mounting hole through the second return oil channel 19; the fourth return oil through hole 1401 on the valve plunger sleeve 14 is connected to the second return oil channel 19; when the valve plunger 15 is in the initial position, the valve plunger 15 blocks the fourth return oil 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 return oil through hole 1401 on the valve plunger sleeve 14, thereby connecting the hydraulic oil circuit with the second return oil channel 19;

[0056] A relief valve mounting hole is provided on one side end surface of the lower valve body 2, and the relief valve 20 is provided in the relief valve mounting hole. The second oil return channel 19 flows through the flow control hole of the relief valve 20. A second stepper motor is provided outside the lower valve body 2, and 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 of the second oil return channel 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 the 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 also 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 and the cam plunger sleeve 8 are interference fit; 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; an annular groove 903 is provided on the outer wall of the cam plunger sleeve 9 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 is extended inward at 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 , and the valve plunger 15 is ground and matched with the valve plunger sleeve 14 ; the outer wall of the valve plunger sleeve 14 has an annular groove 1403 for mounting a sealing ring.

[0063] The outer wall of the valve plunger 15 is provided with a plurality of annular grooves 1501 , and the hydraulic oil is stored in the annular grooves 1501 to prevent the formation of 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] The present invention is mainly devoted to developing a valve control mechanism suitable for multiple combustion modes, which can switch the valve profile suitable for the current combustion mode between different combustion modes. Therefore, when the engine is working, according to the calibration results in MAP, when the engine speed, load and excess air coefficient are within the SICI combustion mode range, the valve is adjusted to a profile suitable for SICI.

[0068] The present invention is designed for a single-cylinder engine, installed outside the cylinder head of the engine, and connected to the valve to control the valve. The single-cylinder engine has two working chambers, so the above structure includes at least two groups in the valve body. The camshaft is installed outside the cylinder head of the engine through a bearing, and the cam on the camshaft contacts the surface of the cam plunger 10.

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

[0070] When the engine is working, the camshaft rotates, the cam squeezes the cam plunger 10, and the hydraulic oil in the plunger cavity 1002 of the cam plunger 10 enters the high-pressure oil chamber through the first channel. When the pressure in the high-pressure oil chamber is high enough, the hydraulic oil enters the second channel 16 through the one-way valve of the lower high-pressure oil chamber 12, 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 to open the valve, ensuring the stable operation of the engine.

[0071] In the valve opening stage, after the valve plunger 15 squeezes the valve spring by 2mm, the fourth oil return hole 1401 on the valve plunger sleeve 14 leaks out, and the fourth oil return hole 1401 on the valve plunger sleeve 14, the second oil return channel 19, and the oil return joint 18 are connected in sequence; when the engine is running under the ignition condition, the first stepper motor adjusts the control valve of the external joint to reduce the amount of oil returning to the hydraulic station from the external joint at this time. At this time, most of the hydraulic oil 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 joint 18. Driving the second stepper motor to adjust the opening of the overflow 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 2 mm and ensuring the life of the engine.

[0072] When the engine combustion mode is converted 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 convex tip, during the return of the cam plunger 10, the vacuum suction force in the plunger cavity 1002 causes the hydraulic oil in the valve plunger mounting hole 13 to be sucked 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 sleeve 8, and then flows back to the hydraulic station through the first oil return channel 11 and the external connector. By adjusting the opening of the control valve of the external connector, the return oil volume can be adjusted, thereby changing the valve lift and the valve closing time, which can ensure that the valve closing time is greatly advanced under the premise that the valve opening time does not change much, increase the negative valve overlap angle, and realize new combustion modes such as SICI and HCCI.

[0073] Combination Fig.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 condition, 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 condition, 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 operation of the engine;

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

[0081] If the working condition at this time is not within the SICI and HCCI working condition range calibrated in the MAP, the second stepper motor is driven to adjust the opening of the relief valve 20, so as to adjust the valve lift and duration to be suitable for the current working condition;

[0082] If the operating condition is within the SICI and HCCI operating range calibrated in the MAP, the first stepper motor is driven to open the control valve of the external connector, adjust the valve lift and closing time, and ensure that the engine maintains working in the SICI combustion mode.

Claims

1. An engine variable valve control device, characterized in that: It comprises a valve body and a controller, wherein 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; 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 in cooperation; the cam plunger is arranged in the cam plunger sleeve, and the cam plunger and the cam plunger sleeve are movably installed in cooperation; 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 arranged outside the valve body is connected to a 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; the high-pressure oil chamber is connected to the valve plunger mounting hole through a second channel; a one-way valve is provided between the high-pressure oil chamber and the second channel, and the 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, which is used to speed up the return speed of the hydraulic oil when the valve plunger returns; An oil return joint mounting hole is provided on one side end face of the valve body, the oil return joint is mounted on the oil return joint mounting hole, and the oil return joint is connected to the hydraulic station through an oil pipe; the valve plunger mounting hole and the oil return 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 outside 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 mounting 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 mounted 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: A mounting through hole is provided in the middle of the cam plunger sleeve 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; an annular groove is provided on the outer wall of the cam plunger sleeve 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 is extended inward at 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 is ground and matched with the valve plunger sleeve; 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 condition, 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 condition, 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 operation of the engine; If the water jacket temperature is greater than 30 degrees and the intake air temperature is greater than 25 degrees, then continue to obtain and determine whether the speed and load at this time are within the SICI and HCCI conditions calibrated in the MAP; If the working condition at this time is not within the SICI and HCCI working condition range calibrated in the MAP, the second stepper motor is driven to adjust the opening of the relief valve, and the valve lift and duration are adjusted to be suitable for the current working condition; If the operating condition is within the SICI and HCCI operating range calibrated in the MAP, the first stepper motor is driven to open the control valve of the external connector, adjust the valve lift and closing time, and ensure that the engine maintains working in the SICI combustion mode.

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