Variable valve timing and lift system of engine

Abstract

The invention discloses a variable valve timing and lift system of an engine. The variable valve timing and lift system is of an A type structure and a B type structure. The A-type structure is composed of a crankshaft, a crankshaft gear, a timing chain and other parts, and the B-type structure comprises a crankshaft, a crankshaft helical gear, a transmission helical gear and the like. According to the two structures, the valve opening time, the valve lift, the oil injection time and the ignition time can be accurately and synchronously adjusted through unique design according to the working condition of an engine. Therefore, the unique structure can accurately and synchronously adjust the valve, oil injection and ignition parameters, the power and response performance is improved, the combustion efficiency is high, fuel oil is fully combusted, less harmful gas is discharged, the A-type structure and the B-type structure optimize a valve system, parts are reduced, the two structures are suitable for different engines respectively, various requirements are met, and the market competitiveness is enhanced.

Description

Technical Field

[0001] This application relates to the technical field of engines, and particularly to a variable valve timing and lift system for an engine. Background Art

[0002] In the field of modern engine technology, precise control of valve timing, lift, fuel injection, and ignition timing is crucial for improving engine performance, reducing fuel consumption, and decreasing pollutant emissions. The valve systems of traditional engines usually adopt fixed valve timing and lift settings, which means that under different engine operating conditions, such as idling, low-speed climbing, and high-speed driving, the opening and closing times and the opening degree of the valves cannot be adjusted flexibly, making it difficult for the engine to achieve the best performance state under various operating conditions.

[0003] With the development of technology, although some variable valve timing systems (VVTs) have emerged, such as hydraulically controlled VVT systems, which can change the opening and closing times of the valves according to factors such as engine speed, these systems have obvious deficiencies in valve lift adjustment. Most VVT systems can only achieve a limited number of lift mode switches and cannot achieve continuous and stepless lift adjustment like the present invention, which limits the performance optimization of the engine under complex operating conditions.

[0004] At the same time, the control of fuel injection time and ignition time in the prior art often operates independently of the valve system. This results in a lack of precise coordination between fuel injection, ignition, and valve movement, and the combustion process cannot be fully utilized to improve engine efficiency. For example, during engine acceleration, due to the mismatch between fuel injection, ignition, and valve opening times, incomplete combustion easily occurs, which not only reduces the engine's power output but also increases fuel consumption and pollutant emissions.

[0005] In addition, the valve drive mechanisms of traditional engines have complex structures and numerous components, which not only increase the manufacturing cost of the engine but also raise the probability of failures, increasing the difficulty and cost of maintenance. For example, some engines with multi-camshaft structures, although capable of achieving relatively complex valve control, have complex transmission and coordination mechanisms between the camshafts, resulting in a large overall engine structure and reduced reliability.

[0006] The variable valve timing and lift system (Type A structure and Type B structure) of the present invention for an engine is developed precisely to address the above deficiencies in the prior art, aiming to provide an innovative engine valve system with a compact structure, superior performance, and the ability to achieve precise coordinated control of multiple parameters. Summary of the Invention

[0007] This application aims to solve at least one of the technical problems in the related art to some extent.

[0008] To this end, the first objective of this application is to provide an engine variable valve timing and lift system. Its unique structure can precisely synchronously adjust the valve opening time, lift, fuel injection, and ignition time to achieve the best combustion effect. When running at high speeds, the valve opening is advanced, the valve lift is increased, and fuel injection and ignition are optimized to enhance power. When running at low speeds, the parameters are precisely regulated to enhance torque output and low-speed response.

[0009] The second objective of this application is to provide an engine variable valve timing and lift system. Fuel injection, ignition, and valve movement are highly coordinated to improve combustion efficiency, enable full combustion of fuel, and reduce waste.

[0010] The third objective of this application is to provide an engine variable valve timing and lift system. Precise combustion control makes combustion more complete, reduces the generation of harmful gases such as carbon monoxide, hydrocarbons, and nitrogen oxides, and meets the requirements of strict environmental protection regulations.

[0011] The fourth objective of this application is to provide an engine variable valve timing and lift system. The A-type and B-type structures optimize the engine valve system, reduce the number of components, and simplify the structure.

[0012] The fifth objective of this application is to provide an engine variable valve timing and lift system. The A-type structure is suitable for gasoline engines with high requirements for structural compactness and response speed, and the B-type structure is suitable for diesel engines with high torque output requirements and harsh working environments. The diverse structures meet the needs of different users and application scenarios and enhance the market competitiveness of the product.

[0013] To achieve the above object, an embodiment of the first aspect of the present application provides a variable valve timing and lift system (Type A structure) for an engine, including a crankshaft, a crankshaft gear, a timing chain, a camshaft timing gear, a timing gear baffle, a helical sliding key, a camshaft seat, a camshaft, a valve tappet, a camshaft cam, a valve, a flat pressure bearing, and a camshaft moving helical sliding key. Among them, the end of the crankshaft is fixedly connected to the crankshaft gear; the timing chain is meshed with the crankshaft gear and the camshaft timing gear; the camshaft timing gear is sleeved on the helical sliding key of the camshaft through an inner diameter helical sliding key, rotates driven by the timing chain and forms a differential rotation with the camshaft; the timing gear baffle is fixed on the cylinder head body and restricts the axial movement of the camshaft timing gear; the camshaft is axially movably installed on the cylinder head through the camshaft seat, and its helical sliding key is meshed with the inner diameter helical sliding key of the camshaft timing gear. The axial movement of the camshaft is driven by the camshaft moving helical sliding key, and an injection sensor pulse module and an ignition timing pulse block are integrated; the linear inclined surface of the valve tappet engages with the camshaft cam; the camshaft cam is fixed on the camshaft and pushes the valve tappet to change the valve lift; the valve is linked with the valve tappet through a valve spring; the flat pressure bearing is arranged between the camshaft and the cylinder head body; the camshaft moving helical sliding key is connected to an external driving mechanism to control the axial movement of the camshaft.

[0014] A variable valve timing and lift system for an engine according to an embodiment of the present application has a unique structure that can accurately synchronously adjust valve, injection, and ignition parameters, improve power and response performance, has high combustion efficiency, allows for full combustion of fuel, and has low harmful gas emissions. The Type A and Type B structures optimize the valve system, reduce components, and the two structures are respectively suitable for different engines to meet diverse requirements and enhance market competitiveness.

[0015] In addition, a variable valve timing and lift system for an engine according to the above-mentioned present application may further have the following additional technical features:

[0016] The first aspect embodiment of the present application proposes a variable valve timing and lift system for an engine (Type B structure), including a crankshaft, a crankshaft helical gear, a transmission helical gear, a camshaft timing helical gear, a camshaft, a valve tappet, a camshaft cam, a valve, a valve push rod, a rocker arm, and a camshaft journal. Among them, the end of the crankshaft is fixedly connected to the crankshaft helical gear; the transmission helical gear meshes with the crankshaft helical gear and has a width more than twice that of the camshaft timing helical gear; the camshaft timing helical gear is fixed on the camshaft and meshes with the transmission helical gear to rotate differentially; the camshaft is axially movably mounted on the cylinder block through the camshaft journal and moves synchronously with the camshaft timing helical gear; the linear inclined surface of the valve tappet engages with the camshaft cam; the camshaft cam is fixed on the camshaft and pushes the valve tappet to change the valve lift; the valve is linked with the rocker arm through the valve push rod; the valve push rod connects the valve tappet and the rocker arm; the rocker arm is hinged on the cylinder head to amplify the valve lift; the camshaft journal supports the rotational movement of the camshaft.

[0017] In an embodiment of the present application, the moving mechanism of the camshaft includes a helical sliding key, a mechanical centrifugal flyweight, an electromagnetic driving device, an oil pressure driving device, or a worm and worm gear mechanism.

[0018] In an embodiment of the present application, the outer diameter of the valve tappet is square, rectangular, or oval. If it is circular, a positioning pin is provided, and the slope change rate of the parabolic inclined surface is in a proportional relationship with the axial moving speed of the camshaft.

[0019] In an embodiment of the present application, the width of the transmission helical gear is more than twice that of the camshaft timing helical gear, its tooth profile is an involute helical tooth, and the module is the same as that of the crankshaft helical gear.

[0020] In an embodiment of the present application, the fuel injection sensor pulse module and the ignition timing pulse block are integrated on the camshaft, and the fuel injection signal and the ignition signal are synchronously triggered through the axial movement of the camshaft. The phase difference between the fuel injection signal and the ignition signal is linearly related to the valve opening time.

[0021] The advantages of the present application compared with the existing technology are as follows:

[0022] (1) The unique structure can accurately synchronously adjust the valve opening time, lift, fuel injection, and ignition time to achieve the best combustion effect. Advance the valve opening, increase the valve lift, and optimize fuel injection and ignition at high speeds to improve power. Precisely control the parameters at low speeds to enhance torque output and low-speed response.

[0023] (2) The fuel injection, ignition, and valve movement are highly coordinated, improving the combustion efficiency, enabling the fuel to burn fully, and reducing waste.

[0024] (3)Precise combustion control enables more complete combustion, reducing the generation of harmful gases such as carbon monoxide, hydrocarbons, and nitrogen oxides, meeting the requirements of strict environmental protection regulations.

[0025] (4)The valve systems of the A-type and B-type structures optimize the engine, reducing the number of components and simplifying the structure.

[0026] (5)The A-type structure is suitable for gasoline engines with high requirements for structural compactness and response speed, and the B-type structure is suitable for diesel engines with high torque output requirements and harsh working environments. The diverse structures meet the needs of different users and application scenarios, enhancing the market competitiveness of the product.

[0027] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. Description of the Drawings

[0028] The above-mentioned and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of the embodiments in conjunction with the drawings, where:

[0029] Figure 1 FIG. is a schematic structural diagram of the A-type of an engine variable valve timing and lift system according to an embodiment of the present application;

[0030] Figure 2 FIG. is a schematic structural diagram of the B-type of an engine variable valve timing and lift system according to an embodiment of the present application.

[0031] As shown in the figure: A1, crankshaft; A2, crankshaft gear; A3, timing chain; A4, camshaft timing gear; A5, timing gear baffle; A6, helical sliding key; A7, camshaft seat; A8, camshaft; A9, valve tappet; A10, camshaft cam; A11, valve; A12, flat pressure bearing; A13, camshaft moving helical sliding key; B1, crankshaft; B2, crankshaft helical gear; B3, transmission helical gear; B4, camshaft timing helical gear; B8, camshaft; B9, valve tappet; B10, camshaft cam; B11, valve; B14, valve push rod; B15, rocker arm; B16, camshaft journal. Detailed Description of the Embodiments

[0032] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0033] The following describes a variable valve timing and lift system for an engine according to an embodiment of the present application in conjunction with the accompanying drawings.

[0034] As Figure 1 - Figure 2 shown, a variable valve timing and lift system (Type A structure) for an engine according to an embodiment of the present application may include a crankshaft A1, a crankshaft gear A2, a timing chain A3, a camshaft timing gear A4, a timing gear baffle A5, a helical sliding key A6, a camshaft seat A7, a camshaft A8, a valve tappet A9, a camshaft cam A10, a valve A11, a flat pressure bearing A12, and a camshaft moving helical sliding key A13.

[0035] It can be understood that during the actual working process of the variable valve timing and lift system (Type A structure) for an engine:

[0036] After the engine starts, the crankshaft A1 begins to rotate. Since the crankshaft gear A2 is fixedly connected to the end of the crankshaft A1, the crankshaft gear A2 rotates together with the crankshaft A1. The rotation of the crankshaft gear A2 drives the timing chain A3 engaged with it, and the timing chain A3 in turn drives the camshaft timing gear A4 to rotate.

[0037] The camshaft timing gear A4 is sleeved on the helical sliding key A6 of the camshaft A8 through an inner diameter helical sliding key. Driven by the timing chain A3, the camshaft timing gear A4 not only rotates itself but also forms a differential rotation with the camshaft A8. At this time, the timing gear baffle A5 fixed on the cylinder head plays a role in restricting the axial movement of the camshaft timing gear A4 to ensure that the camshaft A8 can move axially independently.

[0038] When it is necessary to adjust the valve timing, lift, and fuel injection and ignition times, the external drive mechanism will drive the camshaft moving helical sliding key A13, thereby driving the camshaft A8 to move axially. Since the helical sliding key A6 of the camshaft A8 and the inner diameter helical sliding key of the camshaft timing gear A4 always remain in an engaged state, the rotation of the camshaft timing gear A4 is not affected during the axial movement of the camshaft A8.

[0039] As the camshaft A8 rotates and moves axially, the camshaft cam A10 fixed on the camshaft A8 also moves accordingly. The camshaft cam A10 pushes the valve tappet A9 engaged with it, and the linear inclined surface of the valve tappet A9 cooperates with the camshaft cam A10 to cause the valve tappet A9 to move up and down. Since the valve A11 is linked to the valve tappet A9 through a valve spring, the movement of the valve tappet A9 will be transmitted to the valve A11, thereby changing the lift of the valve A11 and achieving the control of the engine intake and exhaust.

[0040] Meanwhile, the flat pressure bearing A12 disposed between the camshaft A8 and the cylinder head body can reduce the frictional resistance during the axial movement of the camshaft A8, ensuring the smooth movement of the camshaft A8. Moreover, the fuel injection sensor pulse module and the ignition timing pulse block integrated on the camshaft A8 will synchronously trigger the fuel injection signal and the ignition signal as the camshaft A8 axially moves, achieving the coordinated control of fuel injection, ignition, and valve movement to meet the operating requirements of the engine under different working conditions.

[0041] As Figure 1 - Figure 2 shown, a variable valve timing and lift system (Type B structure) of an engine according to an embodiment of the present application may include a crankshaft B1, a crankshaft helical gear B2, a transmission helical gear B3, a camshaft timing helical gear B4, a camshaft B8, a valve tappet B9, a camshaft cam B10, a valve B11, a valve push rod B14, a rocker arm B15, and a camshaft journal B16.

[0042] It can be understood that when the variable valve timing and lift system (Type B structure) of the engine works:

[0043] The engine starts, and the crankshaft B1 begins to rotate. Since the crankshaft helical gear B2 is fixedly connected to the end of the crankshaft B1, the crankshaft helical gear B2 rotates synchronously with the crankshaft B1.

[0044] When the crankshaft helical gear B2 rotates, it drives the transmission helical gear B3 meshing with it to rotate. The width of the transmission helical gear B3 is more than twice that of the camshaft timing helical gear B4, and this design ensures that the transmission helical gear B3 and the camshaft timing helical gear B4 always maintain stable meshing when the camshaft B8 axially moves.

[0045] The camshaft timing helical gear B4 is fixed on the camshaft B8. Driven by the transmission helical gear B3, the camshaft timing helical gear B4 drives the camshaft B8 to rotate. At the same time, the two rotate with a differential, and the camshaft B8 is axially movably mounted on the cylinder block through the camshaft journal B16 and moves synchronously with the camshaft timing helical gear B4. The camshaft journal B16 provides support for the camshaft B8 to ensure the smoothness of its rotational movement.

[0046] It should be noted that the size of the camshaft timing helical gear B4 is twice that of the crankshaft helical gear B2, and the camshaft timing helical gear B4, the crankshaft helical gear B2, and the transmission helical gear B3 are in a helical "plug-in rotation".

[0047] As the camshaft B8 rotates and axially moves, the camshaft cam B10 fixed on the camshaft B8 also moves together. The camshaft cam B10 pushes the valve tappet B9 engaged with it. Due to the linear inclined surface of the valve tappet B9 cooperating with the camshaft cam B10, the valve tappet B9 will move up and down.

[0048] The movement of the valve tappet B9 is transmitted to the rocker arm B15 through the valve push rod B14, and the valve push rod B14 connects the valve tappet B9 and the rocker arm B15. The rocker arm B15 is hinged to the cylinder head and serves to amplify the valve lift, transmitting the amplified movement of the valve push rod B14 to the valve B11. Since the valve B11 is linked with the valve push rod B14 and the rocker arm B15, the movement of the rocker arm B15 drives the valve B11 to open and close, realizing the control of the engine intake and exhaust, and further changing the valve lift to meet the requirements of different engine operating conditions.

[0049] In an embodiment of the present application, as Figure 1 - Figure 2 shown, the moving mechanism of the camshaft A8 / B8 includes a helical spline, a mechanical centrifugal flyweight, an electromagnetic driving device, an oil pressure driving device or a worm and worm gear mechanism.

[0050] It can be understood that the helical spline drives

[0051] Taking the A-type structure as an example, when the helical spline is used to drive the movement of the camshaft A8, the camshaft moving helical spline A13 is connected to the camshaft A8. The external power source (such as a motor through a transmission component) directly acts on the camshaft moving helical spline A13 to cause it to have an axial displacement. Due to the connection relationship between the camshaft moving helical spline A13 and the camshaft A8, the camshaft A8 moves axially accordingly. At the same time, the helical spline A6 on the camshaft A8 and the inner diameter helical spline of the camshaft timing gear A4 always remain meshed. During the movement of the camshaft A8, the camshaft timing gear A4 continues to rotate under the drive of the timing chain A3, realizing the differential rotation of the camshaft A8, thereby adjusting the valve opening time, lift, and fuel injection and ignition time. In the B-type structure, a similar helical spline principle can also be applied to the movement control of the camshaft B8, realizing the axial movement and differential rotation of the camshaft B8 through the cooperation of the corresponding helical spline structure and the external power.

[0052] The mechanical centrifugal flyweight drives

[0053] In the mechanical centrifugal flyweight drive mode, when the engine is running, the rotation of the crankshaft (A1 or B1) drives the mechanical centrifugal flyweight mechanism. Taking the A-type structure as an example, the mechanical centrifugal flyweights are installed on the rotating components related to the crankshaft A1 (indirectly connected through transmission gears, for example). As the rotational speed of the crankshaft A1 increases, the centrifugal flyweights expand outward under the action of centrifugal force. The movement of the flyweights is transmitted to the camshaft moving helical spline A13 through a series of linkage mechanisms. When the flyweights expand to a certain extent, they push the camshaft moving helical spline A13 to move axially, and then drive the camshaft A8 to move axially, realizing the adjustment of valve and fuel injection ignition parameters. The working principle of the B-type structure is similar. The crankshaft B1 drives the mechanical centrifugal flyweight mechanism, and finally drives the camshaft B8 to move through relevant connection structures to meet the requirements of different engine operating conditions.

[0054] Driven by an electromagnetic drive device

[0055] For the electromagnetic drive device to drive the camshaft (A8 / B8) to move, taking the A-type structure as an example, the electromagnetic drive device mainly consists of components such as electromagnetic coils and iron cores. When the engine control unit issues a control signal according to the engine operating conditions, the electromagnetic coil is energized to generate a magnetic field, attracting the iron core to move. The iron core is connected to the camshaft moving helical spline A13, and the movement of the iron core drives the camshaft moving helical spline A13, and then pushes the camshaft A8 to move axially. In this process, the helical spline A6 of the camshaft A8 interacts with the inner diameter helical spline of the camshaft timing gear A4 to achieve the differential rotation and parameter adjustment of the camshaft A8. In the B-type structure, the electromagnetic drive device also realizes the precise control of the camshaft B8 by controlling the connection between the iron core and the relevant moving components of the camshaft B8.

[0056] Driven by an oil pressure drive device

[0057] In the oil pressure drive mode, taking the A-type structure as a reference, the oil pressure drive device mainly includes components such as oil pumps, oil pipes, and oil cylinders. When the engine is running, the oil pump pressurizes the oil and transports it to the oil cylinder through the oil pipe. The piston of the oil cylinder is connected to the camshaft moving helical spline A13. When the oil cylinder is filled with high-pressure oil, the piston generates an axial thrust under the action of the oil pressure, pushing the camshaft moving helical spline A13, and then driving the camshaft A8 to move axially. During the movement, the helical spline A6 of the camshaft A8 cooperates with the camshaft timing gear A4 to complete the differential rotation and parameter adjustment. In the B-type structure, the working mode of the oil pressure drive device is similar, and the movement of the camshaft B8 is controlled by the oil pressure to push the relevant components to meet the performance requirements of the engine under different operating conditions.

[0058] Driven by a worm and worm gear mechanism

[0059] When driven by a worm and worm gear mechanism, taking the A-type structure as an example, the motor drives the worm to rotate, and the worm meshes with the worm wheel. The worm wheel is connected to the camshaft moving helical spline A13. When the worm rotates, it drives the worm wheel to rotate. Due to the connection relationship between the worm wheel and the camshaft moving helical spline A13, the rotation of the worm wheel is converted into the axial movement of the camshaft moving helical spline A13, thereby pushing the camshaft A8 to move axially. At the same time, the helical spline A6 on the camshaft A8 cooperates with the camshaft timing gear A4 to achieve differential rotation and system parameter adjustment. The principle of using the worm and worm gear mechanism to drive the movement of the camshaft B8 in the B-type structure is the same. By controlling the rotation of the worm with the motor, the worm wheel and related connecting components are driven to achieve precise control of the camshaft B8.

[0060] In an embodiment of the present application, as Figure 1 - Figure 2 shown, the outer diameter of the valve tappet (A9 / B9) is square, rectangular or oval. If it is circular, a positioning pin is provided, and the slope change rate of the parabolic inclined surface is in a proportional relationship with the axial movement speed of the camshaft (A8 / B8).

[0061] It can be understood that when the engine is running, the camshaft (A8 / B8) will move axially under the action of the corresponding drive mechanism. Taking the A-type structure as an example, when the camshaft A8 moves axially, the camshaft cam A10 fixed on the camshaft A8 also moves accordingly.

[0062] The outer diameter of the valve tappet A9 is designed to be square, rectangular or oval. This non-circular design can effectively prevent the valve tappet A9 from rotating during movement, ensuring that it always maintains stable contact and the correct movement trajectory with the camshaft cam A10. If the outer diameter of the valve tappet A9 is circular, a positioning pin (not detailed in the figure) will be provided, and the positioning pin cooperates with the corresponding structure on the engine block or other fixed components, also playing a role in restricting the rotation of the valve tappet A9.

[0063] At the same time, the valve tappet A9 has a parabolic inclined surface, and its slope change rate is in a proportional relationship with the axial movement speed of the camshaft A8. When the camshaft A8 moves axially at a certain speed, the camshaft cam A10 will contact and push the parabolic inclined surface of the valve tappet A9 to move. Due to the special geometric shape of the parabolic inclined surface, as the axial movement speed of the camshaft A8 increases, the rising or falling speed of the valve tappet A9 will also increase accordingly; conversely, when the axial movement speed of the camshaft A8 slows down, the movement speed of the valve tappet A9 will also slow down.

[0064] For example, when the engine is running at high speed and requires more intake air, the axial movement speed of the camshaft A8 increases. At this time, the rate of change of the slope of the parabolic inclined surface of the valve tappet A9 increases, enabling the valve tappet A9 to rise rapidly, thereby pushing the valve A11 to open quickly and to a greater extent, meeting the engine's demand for intake air. When the engine is running at low speed, the axial movement speed of the camshaft A8 is slower, the rate of change of the slope of the parabolic inclined surface of the valve tappet A9 is smaller, the valve tappet A9 rises slowly, and the opening speed and degree of the valve A11 are both smaller, ensuring the stable operation of the engine under low-speed conditions.

[0065] In the B-type structure, the working principle is similar to that of the A-type structure. The axial movement of the camshaft B8 drives the movement of the camshaft cam B10. Similarly, the valve tappet B9 ensures movement stability through its special outer diameter shape (square, rectangular, oval, or circular with a positioning pin). Moreover, the rate of change of the slope of the parabolic inclined surface of the valve tappet B9 is directly proportional to the axial movement speed of the camshaft B8, enabling the valve tappet B9 to precisely adjust its position according to the movement of the camshaft B8, and then precisely controlling the lift of the valve B11 through the valve push rod B14 and the rocker arm B15 to meet the intake and exhaust requirements of the engine under different working conditions.

[0066] In an embodiment of the present application, as Figure 1 - Figure 2 shown, the width of the transmission helical gear B3 is more than twice that of the camshaft timing helical gear B4, its tooth profile is an involute helical tooth, and the module is the same as that of the crankshaft helical gear B2.

[0067] It can be understood that after the engine starts, the crankshaft B1 begins to rotate, and the crankshaft helical gear B2 fixedly connected to its end rotates synchronously. Since the crankshaft helical gear B2 meshes with the transmission helical gear B3, the rotational driving force of the crankshaft helical gear B2 is transmitted to the transmission helical gear B3, driving the transmission helical gear B3 to rotate around its own axis.

[0068] The transmission helical gear B3 has a unique design, and its width is more than twice that of the camshaft timing helical gear B4. This design shows important advantages when the camshaft B8 moves axially. When the engine working condition changes and the camshaft B8 needs to move axially to adjust the valve timing and lift, even if the camshaft B8 drives the camshaft timing helical gear B4 to generate an axial displacement, the transmission helical gear B3 and the camshaft timing helical gear B4 can still maintain a stable meshing state. Because the transmission helical gear B3 is wide enough, it can ensure that during the movement of the camshaft B8, there is always enough tooth surface meshing with the camshaft timing helical gear B4, avoiding tooth disengagement or poor meshing, and ensuring the continuity and stability of power transmission.

[0069] In addition, the tooth profile of the transmission helical gear B3 is an involute helical tooth, and its module is the same as that of the crankshaft helical gear B2. The involute helical tooth profile can make the contact stress distribution between the tooth surfaces more uniform during the meshing process of the gears, the transmission more stable, and reduce the noise and vibration during the transmission process. This characteristic of the same module ensures the correct meshing relationship between the crankshaft helical gear B2 and the transmission helical gear B3, enabling power to be efficiently and stably transmitted from the crankshaft helical gear B2 to the transmission helical gear B3.

[0070] The transmission helical gear B3 transmits the power obtained from the crankshaft helical gear B2 to the camshaft timing helical gear B4 that meshes with it. Since the camshaft timing helical gear B4 is fixed on the camshaft B8, the camshaft timing helical gear B4 drives the camshaft B8 to rotate around its own axis under the drive of the transmission helical gear B3. During the rotation of the camshaft B8, the valve tappet B9 is pushed by the camshaft cam B10, thereby controlling the opening and closing of the valve B11, achieving precise control of the engine intake and exhaust processes, and meeting the performance requirements of the engine under different operating conditions.

[0071] In an embodiment of the present application, as Figure 1 - Figure 2 shown, the fuel injection sensor pulse module and the ignition timing pulse block are integrated on the camshaft A8, and the fuel injection signal and the ignition signal are synchronously triggered by the axial movement of the camshaft A8. The phase difference between the fuel injection signal and the ignition signal is linearly related to the valve opening time.

[0072] It can be understood that the axial movement of the camshaft A8

[0073] When the engine is running, the external drive mechanism will drive the camshaft moving helical key A13 according to the operating conditions of the engine, such as parameters like rotational speed and load. Since the camshaft moving helical key A13 is connected to the camshaft A8, it will drive the camshaft A8 to perform axial movement under the support of the camshaft seat A7. At the same time, the helical key A6 on the camshaft A8 and the inner diameter helical key of the camshaft timing gear A4 always remain meshed. The camshaft timing gear A4 rotates under the drive of the timing chain A3, causing the camshaft A8 to rotate while performing axial movement.

[0074] The triggering of the fuel injection signal and the ignition signal

[0075] The fuel injection sensor pulse module and the ignition timing pulse block integrated on the camshaft A8 will move with the axial movement of the camshaft A8. When the camshaft A8 moves to a specific position, the fuel injection sensor pulse module will trigger the fuel injection signal. This signal will be transmitted to the fuel injection system of the engine to control the fuel injector to inject fuel into the cylinder at the appropriate moment.

[0076] Meanwhile, the ignition timing pulse block also triggers the ignition signal at the corresponding position. The ignition signal is transmitted to the ignition system, causing the spark plug to generate an electric spark at the appropriate moment to ignite the mixture gas in the cylinder.

[0077] The correlation between the phase difference of the fuel injection signal and the ignition signal and the valve opening time

[0078] During the operation of the engine, the opening and closing of valve A11 are controlled by the camshaft cam A10 on the camshaft A8. The camshaft cam A10 pushes the valve tappet A9, and the valve tappet A9 is linked to the valve A11 through the valve spring, thus realizing the opening and closing actions of the valve A11.

[0079] Since the fuel injection signal and the ignition signal are triggered by the axial movement of the camshaft A8, and the opening time of the valve A11 also depends on the rotation and axial position of the camshaft A8, the phase difference between the fuel injection signal and the ignition signal is linearly related to the valve opening time.

[0080] For example, when the engine is operating at high speed, in order to ensure complete combustion and improve power output, it is necessary to advance the valve opening time. At this time, the camshaft A8 will axially move to the corresponding position, causing the fuel injection sensor pulse module to trigger the fuel injection signal in advance, and the ignition timing pulse block will also trigger the ignition signal in advance. Moreover, the phase difference between the fuel injection signal and the ignition signal will also be adjusted accordingly according to the advance amount of the valve opening time to ensure that the fuel is injected into the cylinder at the appropriate moment and is ignited at the proper time, thereby realizing the efficient operation of the engine under high-speed conditions.

[0081] On the contrary, when the engine is operating at low speed, the valve opening time will be relatively delayed, the axial position of the camshaft A8 changes, the triggering times of the fuel injection signal and the ignition signal will also be delayed accordingly, and their phase difference will also change with the delay of the valve opening time to meet the requirements of the engine's low-speed conditions.

[0082] It should be noted that the control method of this application can be automatically controlled by a controller. The control method of the controller can be realized by simple programming by those skilled in the art and belongs to the common knowledge in this field. And this application is mainly used to protect the mechanical structure, so the control method and circuit connection of this application will not be explained in detail.

[0083] Specifically, assume that a car equipped with the variable valve timing and lift system of this engine is in an accelerating condition. Taking the A-type structure as an example, its specific usage process is as follows:

[0084] After the vehicle starts, the engine runs and the crankshaft A1 begins to rotate at high speed. Since the end of the crankshaft A1 is fixedly connected to the crankshaft gear A2, the crankshaft gear A2 rotates at high speed together with the crankshaft A1. The crankshaft gear A2 drives the timing chain A3 engaged with it to run quickly, and then drives the camshaft timing gear A4 to rotate at high speed.

[0085] At this time, when the vehicle accelerates, more intake air volume and precise fuel injection and ignition coordination are required. The engine control unit determines that it is necessary to adjust the valve timing, lift, fuel injection, and ignition timing based on information such as the engine speed and load feedback from the sensors. Then, it controls the external drive mechanism (assumed to be an oil pressure drive device) to work. The oil pump pressurizes the oil fluid and transports the high-pressure oil fluid through the oil pipe to the oil cylinder connected to the camshaft moving helical key A13. The piston in the oil cylinder generates an axial thrust under the action of the oil pressure, pushing the camshaft moving helical key A13, and then driving the camshaft A8 to move axially quickly.

[0086] During the axial movement of the camshaft A8, its helical key A6 always remains engaged with the inner diameter helical key of the camshaft timing gear A4. The camshaft timing gear A4 continues to rotate at high speed driven by the timing chain A3, realizing the differential rotation of the camshaft A8.

[0087] As the camshaft A8 rotates and moves axially quickly, the camshaft cam A10 fixed on the camshaft A8 also moves quickly. The camshaft cam A10 pushes the valve tappet A9 engaged with it. Since the parabola-shaped slope change rate of the valve tappet A9 is proportional to the axial movement speed of the camshaft A8, at this time, as the camshaft A8 moves quickly, the parabola-shaped slope change rate of the valve tappet A9 increases, and the valve tappet A9 rises quickly. The valve A11 is linked to the valve tappet A9 through the valve spring. The quick rise of the valve tappet A9 drives the valve A11 to open quickly and to a greater extent, meeting the demand for more intake air volume when the engine accelerates.

[0088] At the same time, the fuel injection sensor pulse module and the ignition timing pulse block integrated on the camshaft A8 move axially quickly with the camshaft A8. When the camshaft A8 moves to a specific position, the fuel injection sensor pulse module triggers the fuel injection signal in advance. This signal is transmitted to the fuel injection system to control the fuel injector to inject more fuel into the cylinder quickly. Almost simultaneously, the ignition timing pulse block also triggers the ignition signal in advance. The ignition signal is transmitted to the ignition system, causing the spark plug to generate an electric spark at the appropriate moment to ignite the increased mixture gas in the cylinder. Since the phase difference between the fuel injection signal and the ignition signal is linearly related to the valve opening time, under the acceleration condition, the valve opens in advance, and the fuel injection and ignition signals also advance accordingly, and the phase difference is adjusted according to the advance amount of the valve opening time, ensuring that the fuel burns fully, providing strong power for the engine, and realizing the rapid acceleration of the vehicle.

[0089] Throughout the process, the flat pressure bearing A12 set between the camshaft A8 and the cylinder head block reduces the frictional resistance when the camshaft A8 moves axially, ensuring that the camshaft A8 can move smoothly and quickly. The timing gear baffle A5 fixed on the cylinder head block restricts the axial movement of the camshaft timing gear A4, ensuring that the camshaft A8 can move axially independently to meet the precise control requirements of the engine for the variable valve timing and lift system under acceleration conditions.

[0090] In summary, for the variable valve timing and lift system of an engine in an embodiment of the present application, the unique structure can accurately synchronously adjust valve, injection, and ignition parameters, improve power and response performance, has a high combustion efficiency, enables full combustion of fuel, and reduces harmful gas emissions. The A and B type structures optimize the valve system, reduce the number of components, and the two structures are respectively applicable to different engines to meet diverse requirements and enhance market competitiveness.

[0091] In the description of this specification, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0092] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0093] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A variable valve timing and lift system for an engine (Type A structure), characterized in that It includes a crankshaft (A1), a crankshaft gear (A2), a timing chain (A3), a camshaft timing gear (A4), a timing gear baffle (A5), a helical spline (A6), a camshaft seat (A7), a camshaft (A8), a valve tappet (A9), a camshaft cam (A10), a valve (A11), a plain pressure bearing (A12) and a camshaft moving helical spline (A13). Among them, The end of the crankshaft (A1) is fixedly connected to the crankshaft gear (A2); The timing chain (A3) is meshed with the crankshaft gear (A2) and the camshaft timing gear (A4); The camshaft timing gear (A4) is sleeved on the helical spline (A6) of the camshaft (A8) through an inner diameter helical spline, is driven by the timing chain (A3) to rotate and forms a differential rotation with the camshaft (A8); The timing gear baffle (A5) is fixed on the cylinder head body and restricts the axial movement of the camshaft timing gear (A4); The camshaft (A8) is axially movably installed on the cylinder head through the camshaft seat (A7), its helical spline (A6) is meshed with the inner diameter helical spline of the camshaft timing gear (A4), the axial movement of the camshaft (A8) is driven by the camshaft moving helical spline (A13), and an injection sensor pulse module and an ignition timing pulse block are integrated; The linear inclined surface of the valve tappet (A9) engages with the camshaft cam (A10); The camshaft cam (A10) is fixed on the camshaft (A8) and pushes the valve tappet (A9) to change the valve lift; The valve (A11) is linked with the valve tappet (A9) through a valve spring; The plain pressure bearing (A12) is arranged between the camshaft (A8) and the cylinder head body; The camshaft moving helical spline (A13) is connected to an external driving mechanism to control the axial movement of the camshaft (A8).

2. A variable valve timing and lift system for an engine (Type B structure), characterized in that, It includes a crankshaft (B1), a crankshaft helical gear (B2), a transmission helical gear (B3), a camshaft timing helical gear (B4), a camshaft (B8), a valve tappet (B9), a camshaft cam (B10), a valve (B11), a valve push rod (B14), a rocker arm (B15) and a camshaft journal (B16). Among them, The end of the crankshaft (B1) is fixedly connected to the crankshaft helical gear (B2); The transmission helical gear (B3) is meshed with the crankshaft helical gear (B2) and its width is more than twice that of the camshaft timing helical gear (B4); The camshaft timing helical gear (B4) is fixed on the camshaft (B8) and meshes with the transmission helical gear (B3) to form a differential rotation; The camshaft (B8) is axially movably installed on the cylinder block through the camshaft journal (B16) and moves synchronously with the camshaft timing helical gear (B4); The linear inclined surface of the valve tappet (B9) engages with the camshaft cam (B10); The camshaft cam (B10) is fixed on the camshaft (B8) and pushes the valve tappet (B9) to change the valve lift; The valve (B11) is linked with the rocker arm (B15) through the valve push rod (B14); The valve push rod (B14) connects the valve tappet (B9) and the rocker arm (B15); The rocker arm (B15) is hinged to the cylinder head to amplify the valve lift; The camshaft journal (B16) supports the rotational movement of the camshaft (B8).

3. A variable valve timing and lift system for an engine according to claim 1 or 2, characterized in that, The moving mechanism of the camshaft (A8 / B8) includes a helical spline, a mechanical centrifugal flyweight, an electromagnetic drive device, an oil pressure drive device or a worm and worm gear mechanism.

4. An engine variable valve timing and lift system according to claim 1 or 2, characterized in that, The outer diameter of the valve tappet (A9 / B9) is square, rectangular or oval. If it is circular, a locating pin is provided. The slope change rate of the parabolic inclined plane is directly proportional to the axial movement speed of the camshaft (A8 / B8).

5. An engine variable valve timing and lift system according to claim 2, wherein, The width of the transmission helical gear (B3) is more than twice that of the camshaft timing helical gear (B4). Its tooth profile is an involute helical tooth, and the module is the same as that of the crankshaft helical gear (B2).

6. A variable valve timing and lift system for an engine according to claim 1, wherein, The fuel injection sensor pulse module and the ignition timing pulse block are integrated on the camshaft (A8). The fuel injection signal and the ignition signal are synchronously triggered by the axial movement of the camshaft (A8). The phase difference between the fuel injection signal and the ignition signal is linearly related to the valve opening time.

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