A motor-driven variable valve lift rocker arm mechanism

Abstract

The present invention discloses an electric-motor-driven variable valve lift rocker arm mechanism, belonging to the technical field of reciprocating piston internal combustion engines. One end of the rocker arm is connected with a lift component. The input end of the lift component is in contact connection with a cam through a push rod and a tappet. A rocker arm shaft is arranged in the middle of the rocker arm. A driving component is arranged on one side of the rocker arm shaft. The other end of the rocker arm is in contact connection with a valve. The lift component includes an adjustable lift stud. A threaded through hole is arranged at one end of the rocker arm. The adjustable lift stud is installed in the threaded through hole. The adjustable lift stud and the threaded through hole form a screw rod transmission pair. A worm wheel is arranged at one end of the adjustable lift stud, and the other end is in close fit with the push rod, solving the problems that the existing variable valve lift motion mechanism requires a complex transformation mechanism or has a long control oil circuit, slow response, and much oil leakage along the way.

Description

Technical Field

[0001] The present invention belongs to the technical field of reciprocating piston internal combustion engines, and particularly relates to an electric motor-driven variable valve lift rocker arm mechanism. Background Art

[0002] For traditional reciprocating piston internal combustion engines, the cam profile of the camshaft and the structure of the valve train are fixed, which results in a fixed and unchangeable variation law of the valve lift curve with respect to the crankshaft angle.

[0003] Internal combustion engines are mostly used in automobiles, and the working conditions of automobiles are complex and changeable, with drastic speed changes. The fixed valve lift curve can only achieve the optimal intake and exhaust performance under certain working condition speeds during the operation of the internal combustion engine, and this lift curve cannot take into account good responses in both the high-speed and low-speed regions of the engine.

[0004] The fixed cam profile design is often a compromise choice for the engine under all working conditions, and the result is that the engine can neither obtain the best high-speed efficiency nor the best low-speed torque.

[0005] With the continuous development of engines, variable valve lift technology has become an important technology in the field of engines. The adoption of a variable valve lift mechanism can change the cam profile of the engine during operation, and different valve profiles are adopted according to different requirements for the intake and exhaust systems in the high-speed and low-speed regions, so as to obtain better engine performance under all working conditions, thereby improving the high-speed power and low-speed torque of the engine.

[0006] At the present stage, variable valve lift motion mechanisms are generally realized by means of variable cams or variable valve bridges, etc. The variable cam method can only be realized by changing the cam position or switching cams and rocker rollers, and often requires complex conversion mechanisms and servo motors for control; the variable height valve bridge realizes the change of valve lift by using the height change of the valve bridge.

[0007] However, for the variable cam method at the present stage, its implementation mechanism is complex, the cost is high, and the compatibility is low; for the variable height valve bridge method, its control oil circuit needs to extend from the solenoid valve to the inside of the valve bridge, the control oil circuit is long, the response is slow, and there is much oil leakage along the way.

[0008] The present invention aims to adopt an electric motor-driven variable valve lift rocker arm mechanism to realize variable control of valve lift in a mechanical way, eliminating the disadvantages of requiring complex conversion mechanisms, long control oil circuits, slow response, and much oil leakage along the way. Summary of the Invention

[0009] To solve the problems raised in the above-mentioned background art, the present invention provides an electric motor-driven variable valve lift rocker arm mechanism, which has the characteristics of realizing variable control of valve lift in a mechanical manner, eliminating the disadvantages of requiring complex conversion mechanisms, having a long control oil circuit, slow response, and a large amount of oil leakage along the way.

[0010] To achieve the above object, the present invention provides the following technical solution: An electric motor-driven variable valve lift rocker arm mechanism includes a rocker arm. One end of the rocker arm is connected with a lift component. The input end of the lift component is in contact connection with a cam through a push rod and a tappet.

[0011] A rocker arm shaft is provided in the middle of the rocker arm. On one side of the rocker arm shaft, there is a driving component, and it cooperates with the lift component to work.

[0012] The other end of the rocker arm is in contact connection with a valve.

[0013] The lift component includes an adjustable lift stud. There is a threaded through hole at one end of the rocker arm, and the adjustable lift stud is installed in the threaded through hole. The adjustable lift stud and the threaded through hole form a screw drive pair. A worm gear is provided at one end of the adjustable lift stud, and the other end is in close fit with the push rod.

[0014] The driving component includes a driving motor connected to the rocker arm shaft and a rocker arm shaft driving gear installed on the rocker arm shaft. The rocker arm shaft driving gear is in transmission connection with a worm gear assembly, and the output end of the worm gear assembly is meshed with the worm gear.

[0015] Preferably, a support for supporting it is provided at the lower part of the rocker arm. A return coil spring is provided on the rocker arm. One end of the return coil spring is connected to the rocker arm, and the other end is connected to the support.

[0016] Preferably, the worm gear and the adjustable lift stud are in spline connection.

[0017] Preferably, the driving component further includes a secondary transmission gear in transmission connection with the rocker arm shaft driving gear and a primary transmission gear assembly in transmission connection with the worm gear assembly. The primary transmission gear assembly and the secondary transmission gear are meshed with each other.

[0018] Preferably, bearings cooperating with the rocker arm are respectively provided at both ends of the rocker arm shaft. The rocker arm shaft driving gear is installed between the two bearings, and the pitch diameter of the top of the rocker arm shaft driving gear is smaller than the diameter of the bearing.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The motor-driven variable valve lift rocker arm mechanism described in the present invention has a driving motor arranged on the rocker arm shaft, which drives the rocker arm shaft drive gear arranged inside the rocker arm shaft. Through the primary transmission gear assembly and the secondary transmission gear driving worm arranged on the rocker arm, the worm gear on the adjustable lift stud at the tail end of the rocker arm is driven to rotate. The adjustable lift stud with threads at the tail end of the rocker arm rotates, causing a change in its height relative to the rocker arm, thereby elongating or shortening the length of the valve mechanism driven by the adjustable lift stud, and further realizing the variable control of the valve lift. The variable control of the valve lift is achieved mechanically, eliminating the disadvantages of complex transformation mechanisms, long control oil circuits, slow response, and much oil leakage along the way.

[0021] 2. The motor-driven variable valve lift rocker arm mechanism described in the present invention meets the requirement of real-time variable control of the valve lift during the operation of the internal combustion engine. It only needs to redesign the rocker arm assembly without modifying the cylinder block and cylinder head, reducing the hardware upgrade cost and having little impact on the strength and structure. Moreover, it has a wide application range and is applicable to internal combustion engines fueled by gasoline, diesel, natural gas, liquefied petroleum gas, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a partially sectional view of the structure in the first working state of the present invention;

[0023] Figure 2 is Figure 1 an enlarged view of the structure at position A in

[0024] Figure 3 It is a partially sectional view of the structure in the second working state of the present invention;

[0025] Figure 4 is a partially sectional view of the top structure of the rocker arm part;

[0026] In the figure: 1. Cam; 2. Tappet; 3. Push rod; 4. Adjustable lift stud; 5. Worm gear; 6. Worm gear assembly; 7. Primary transmission gear assembly; 8. Secondary transmission gear; 9. Rocker arm shaft drive gear; 10. Rocker arm shaft; 11. Return coil spring; 12. Rocker arm; 13. Valve; 14. Driving motor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

[0028] Embodiment 1

[0029] Please refer to Figure 1 、 Figure 2 and Figure 4 ,the present invention provides the following technical solution: A motor-driven variable valve lift rocker arm mechanism, including a rocker arm 12, one end of the rocker arm 12 is connected with a lift component, the input end of the lift component is in contact connection with a cam 1 through a push rod 3 and a tappet 2;

[0030] A rocker arm shaft 10 is provided in the middle of the rocker arm 12, and a driving component is provided on one side of the rocker arm shaft 10, and it cooperates with the lift component to work;

[0031] The other end of the rocker arm 12 is in contact connection with a valve 13;

[0032] The lift component includes an adjustable lift stud 4. A threaded through hole is provided at the tail end of the rocker arm 12, and the adjustable lift stud 4 is installed in the threaded through hole. The adjustable lift stud 4 and the threaded through hole form a screw drive pair. When the adjustable lift stud 4 rotates, it will move up and down relative to the tail end of the rocker arm 12. One end of the adjustable lift stud 4 is provided with a worm gear 5, and the other end is in close fit with the push rod 3;

[0033] The driving component includes a driving motor 14 connected to the rocker arm shaft 10 and a rocker arm shaft driving gear 9 installed on the rocker arm shaft 10. The rocker arm shaft driving gear 9 is in transmission connection with a worm gear assembly 6. The output end of the worm gear assembly 6 is meshed with the worm gear 5. The worm gear 5 drives the adjustable lift stud 4 to rotate. When the adjustable lift stud 4 descends under the action of the internal thread at the tail end of the rocker arm 12, the tail end of the rocker arm 12 will be farther and farther away from the push rod 3, and the distance between the head of the rocker arm 12 and the tail end of the valve 13 will decrease, and the lift for the cam 1 to drive the valve 13 to open will increase.

[0034] Specifically, a support for supporting it is provided at the lower part of the rocker arm 12. A return coil spring 11 is provided on the rocker arm 12. One end of the return coil spring 11 is connected to the rocker arm 12, and the other end is connected to the support. The return coil spring 11 makes the adjustable lift stud 4 on the tail end of the rocker arm 12 closely fit on the push rod 3. The push rod 3 cooperates with the tappet 2, and the tappet 2 cooperates with the cam 1. Under the action of the return coil spring 11, the adjustable lift stud 4 closely fits on the push rod 3, the push rod 3 fits on the tappet 2, and the tappet 2 fits on the cam 1. The return coil spring 11 ensures that there is no gap in this transmission chain.

[0035] Specifically, the worm gear 5 and the adjustable lift stud 4 are in spline connection. The adjustable lift stud 4 can move up and down in the worm gear 5 through the spline, and the worm gear 5 only makes a rotational motion.

[0036] Specifically, the drive assembly further includes a secondary drive gear 8 drivingly connected to the rocker shaft drive gear 9 and a primary drive gear assembly 7 drivingly connected to the worm assembly 6. The primary drive gear assembly 7 and the secondary drive gear 8 are meshed with each other. The worm assembly 6 consists of a worm and a gear. The primary drive gear assembly 7 consists of two gears. The worm of the worm assembly 6 is engaged with the worm gear 5. The gear on the worm assembly 6 is meshed with the primary drive gear assembly 7. The gears of the primary drive gear assembly 7 are meshed with the secondary drive gear 8. The secondary drive gear 8 is meshed with the rocker shaft drive gear 9.

[0037] Specifically, bearings adapted to cooperate with the rocker 12 are respectively provided at both ends of the rocker shaft 10. The rocker shaft drive gear 9 is installed between the two bearings, and the tip diameter of the rocker shaft drive gear 9 is smaller than the diameter of the bearings, ensuring that the rocker shaft 10 can be directly installed on the rocker 12.

[0038] Embodiment 2

[0039] Please refer to Figure 3 and Figure 4 The present invention provides the following technical solution: An electric motor-driven variable valve lift rocker mechanism includes a rocker 12. One end of the rocker 12 is connected to a lift assembly. The input end of the lift assembly is in contact connection with a cam 1 through a push rod 3 and a tappet 2.

[0040] A rocker shaft 10 is provided in the middle of the rocker 12. A drive assembly is provided on one side of the rocker shaft 10 and cooperates with the lift assembly to work.

[0041] The other end of the rocker 12 is in contact connection with a valve 13.

[0042] The lift assembly includes an adjustable lift stud 4. A threaded through hole is provided at the tail end of the rocker 12. The adjustable lift stud 4 is installed in the threaded through hole. The adjustable lift stud 4 and the threaded through hole form a screw drive pair. When the adjustable lift stud 4 rotates, it will move up and down relative to the tail end of the rocker 12. One end of the adjustable lift stud 4 is provided with a worm gear 5, and the other end is in close contact with the push rod 3.

[0043] The drive assembly includes a drive motor 14 connected to the rocker shaft 10 and a rocker shaft drive gear 9 installed on the rocker shaft 10. The rocker shaft drive gear 9 is drivingly connected to a worm assembly 6. The output end of the worm assembly 6 is meshed with the worm gear 5. The worm gear 5 drives the adjustable lift stud 4 to rotate. When the adjustable lift stud 4 rises under the action of the internal thread at the tail end of the rocker 12, the tail end of the rocker 12 will get closer and closer to the push rod 3, and the distance between the head of the rocker 12 and the tail end of the valve 13 increases, and the lift for the cam 1 to drive the valve 13 to open will decrease.

[0044] Specifically, a support for the lower part of the rocker arm 12 is provided. A return coil spring 11 is arranged on the rocker arm 12. One end of the return coil spring 11 is connected to the rocker arm 12, and the other end is connected to the support. The return coil spring 11 makes the adjustable lift stud 4 at the end of the rocker arm 12 closely fit on the push rod 3. The push rod 3 cooperates with the tappet 2, and the tappet 2 cooperates with the cam 1. Under the action of the return coil spring 11, the adjustable lift stud 4 closely fits on the push rod 3, the push rod 3 fits on the tappet 2, and the tappet 2 fits on the cam 1. The return coil spring 11 ensures that there is no gap in this transmission chain.

[0045] Specifically, the worm gear 5 and the adjustable lift stud 4 are in spline connection. The adjustable lift stud 4 can move up and down in the worm gear 5 through the spline, and the worm gear 5 only makes a rotational motion.

[0046] Specifically, the drive assembly further includes a secondary drive gear 8 that is in transmission connection with the rocker shaft drive gear 9, and a primary drive gear assembly 7 that is in transmission connection with the worm gear assembly 6. The primary drive gear assembly 7 and the secondary drive gear 8 are meshed with each other. The worm gear assembly 6 consists of a worm and a gear. The primary drive gear assembly 7 consists of two gears. The worm of the worm gear assembly 6 cooperates with the worm gear 5. The gear on the worm gear assembly 6 is meshed with the primary drive gear assembly 7. The gears of the primary drive gear assembly 7 are meshed with the secondary drive gear 8. The secondary drive gear 8 is meshed with the rocker shaft drive gear 9.

[0047] Specifically, bearings that cooperate with the rocker arm 12 are respectively arranged at both ends of the rocker shaft 10. The rocker shaft drive gear 9 is installed between the two bearings, and the pitch diameter of the top of the teeth of the rocker shaft drive gear 9 is smaller than the diameter of the bearings, ensuring that the rocker shaft 10 can be directly installed on the rocker arm 12.

[0048] By adopting the above technical solutions, in the motor-driven variable valve lift rocker arm mechanism described in the present invention, a drive motor 14 is arranged on the rocker shaft 10 to drive the rocker shaft drive gear 9 arranged inside the rocker shaft 10. The worm gear assembly 6 is driven through the primary drive gear assembly 7 and the secondary drive gear 8 arranged on the rocker arm 12, driving the worm gear 5 on the adjustable lift stud 4 at the end of the rocker arm 12 to rotate. The adjustable lift stud 4 with threads at the end of the rocker arm 12 rotates, causing a change in its height relative to the rocker arm 12, thereby making the length of the valve mechanism driven by the adjustable lift stud 4 extend or shorten, and further realizing the variable control of the valve lift. The variable control of the valve lift is realized in a mechanical way, eliminating the disadvantages of requiring a complex conversion mechanism, having a long control oil circuit, slow response, and much oil leakage along the way.

[0049] Working principle and usage process of the present invention: For the motor-driven variable valve lift rocker arm mechanism described in the present invention, a drive motor 14 is provided on the rocker arm shaft 10 to drive the rocker arm shaft drive gear 9 arranged inside the rocker arm shaft 10. The worm gear assembly 6 is driven through the primary transmission gear assembly 7 and the secondary transmission gear 8 arranged on the rocker arm 12, driving the worm wheel 5 on the adjustable lift stud 4 at the tail end of the rocker arm 12 to rotate. The adjustable lift stud 4 with threads at the tail end of the rocker arm 12 rotates, causing a change in its height relative to the rocker arm 12, thereby causing the length of the valve mechanism driven by the adjustable lift stud 4 to elongate or shorten, and further realizing variable control of the valve lift. By mechanically realizing variable control of the valve lift, the disadvantages of requiring complex conversion mechanisms, long control oil circuits, slow response, and a large amount of oil leakage along the way are eliminated.

[0050] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A motor-driven variable valve lift rocker arm mechanism, characterized in that: It includes a rocker arm (12), one end of the rocker arm (12) is connected with a lift component, and the input end of the lift component is in contact connection with a cam (1) through a push rod (3) and a tappet (2); A rocker shaft (10) is provided in the middle of the rocker arm (12), and a driving component is provided on one side of the rocker shaft (10), and it cooperates with the lift component to work; The other end of the rocker arm (12) is in contact connection with a valve (13); The lift component includes an adjustable lift stud (4). A threaded through hole is provided at one end of the rocker arm (12), and the adjustable lift stud (4) is installed in the threaded through hole. The adjustable lift stud (4) and the threaded through hole form a screw drive pair. A worm gear (5) is provided at one end of the adjustable lift stud (4), and the other end is in close fit with the push rod (3); The driving component includes a driving motor (14) connected to the rocker shaft (10) and a rocker shaft driving gear (9) installed on the rocker shaft (10). The rocker shaft driving gear (9) is in transmission connection with a worm gear component (6), and the output end of the worm gear component (6) is meshed with the worm gear (5).

2. The motor-driven variable valve lift rocker arm mechanism according to claim 1, characterized in that: A support for supporting the rocker arm (12) is provided below the rocker arm (12). A return coil spring (11) is provided on the rocker arm (12). One end of the return coil spring (11) is connected to the rocker arm (12), and the other end is connected to the support; 3. The motor-driven variable valve lift rocker arm mechanism according to claim 1, wherein: The worm gear (5) and the adjustable lift stud (4) are in spline connection; 4. A motor-driven variable valve lift rocker arm mechanism according to claim 1, characterized in that: The driving component further includes a secondary transmission gear (8) in transmission connection with the rocker shaft driving gear (9) and a primary transmission gear assembly (7) in transmission connection with the worm gear component (6). The primary transmission gear assembly (7) and the secondary transmission gear (8) are meshed with each other; 5. A motor-driven variable valve lift rocker arm mechanism according to claim 1, characterized in that: Bearings cooperating with the rocker arm (12) are respectively provided at both ends of the rocker shaft (10). The rocker shaft driving gear (9) is installed between the two bearings, and the pitch diameter of the top of the teeth of the rocker shaft driving gear (9) is smaller than the diameter of the bearings.

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