Mechanism and control method for variable valve lift

Abstract

This invention provides a variable valve lift mechanism and control method. The variable valve lift mechanism includes a camshaft and rocker arm assembly with transmission cooperation, as well as an intake valve, a sliding assembly, and a control unit. The rocker arm assembly includes a rocker arm, which includes a first end arm and a second end arm disposed opposite to each other. The intake valve is rotatably connected to the second end arm. The sliding assembly includes a slider, which is slidably connected to the first end arm. The control unit includes a sliding pin and a solenoid valve. The sliding pin and the slider are independently disposed and transmission cooperationd. By controlling the solenoid valve to close, the sliding pin is driven to move. The sliding pin drives the slider to slide, thereby increasing the downward pressure of the intake valve. This allows the engine to intake less air at low speeds and more air at high speeds and high loads, resulting in more complete fuel combustion at high speeds and high loads, thus reducing fuel consumption and emissions.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and more specifically to a mechanism and control method for variable valve lift. Background Technology

[0002] An engine needs less air intake at low speeds and more air intake at high speeds and under high loads.

[0003] Given that the valve lift of existing engines is not variable, they cannot meet the air demand at both high and low speeds, resulting in poor fuel consumption at high speeds and high loads. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the main objective of this invention is to provide a variable valve lift mechanism and control method. The variable valve lift mechanism is achieved by setting relatively independent and transmission-coordinated sliders and sliding pins, and by controlling the solenoid valve to close to drive the sliding pin to move. The sliding pin drives the slider to slide to increase the downward pressure of the intake valve, so as to realize that the engine intakes less air at low speed and more air intake at high speed and high load, so as to make the fuel combustion more complete at high speed and high load, thereby reducing fuel consumption and emissions.

[0005] To achieve the above objectives, according to a first aspect of the present invention, a mechanism for variable valve lift is provided.

[0006] The variable valve lift mechanism includes:

[0007] A camshaft and rocker arm assembly with transmission cooperation, wherein the rocker arm assembly includes a rocker arm, and the rocker arm includes a first end arm and a second end arm disposed opposite to each other;

[0008] The intake valve is rotatably connected to the second end arm;

[0009] A sliding component includes a slider, which is slidably connected to the first end arm;

[0010] The control unit includes a sliding pin and a solenoid valve. The sliding pin and the slider are independently configured and driven together. By controlling the solenoid valve to close, the sliding pin is driven to move. The sliding pin drives the slider to slide to increase the downward pressure of the intake valve.

[0011] Furthermore, the first end arm is provided with an elongated sliding groove, and the slider is slidably connected to the sliding groove.

[0012] Furthermore, the length of the sliding groove extends from the end of the first end arm toward the end closer to the second end arm.

[0013] Furthermore, the second end arm is provided with a connecting groove, and the end of the intake valve is rotatably connected to the connecting groove.

[0014] Furthermore, the sliding assembly also includes a support body and a first elastic element. The support body has a receiving groove. One end of the slider is slidably connected to the first end arm, and the other end of the slider is slidably connected to the receiving groove. The first elastic element is sandwiched between the slider and the groove wall of the receiving groove, and the first elastic element is disposed opposite to the sliding pin.

[0015] Furthermore, a connecting opening is provided on the wall of the receiving groove, and one end of the sliding pin extends into the receiving groove through the connecting opening to engage with the slider in a transmission manner.

[0016] Furthermore, the control unit also includes a sliding pin and a second elastic element. The sliding pin has a communicating oil storage cavity and a mounting cavity inside. The sliding pin is located in the mounting cavity. One end of the sliding pin is placed at the communication point between the oil storage cavity and the mounting cavity and is slidably connected to the cavity wall of the mounting cavity. The other end is a free end that extends through the cavity wall of the mounting cavity to engage with the slider. The second elastic element is placed in the mounting cavity and is used to make the free end of the sliding pin extend and retract relative to the mounting cavity.

[0017] Furthermore, the sliding pin is externally connected to a first pipe and a second pipe that communicate with the oil storage chamber. The solenoid valve controls the opening and closing of the second pipe, and the first pipe is equipped with a one-way valve.

[0018] Furthermore, the rocker arm assembly also includes a roller and a roller shaft. Both the roller and the rocker arm are mounted on the roller shaft, and the cam on the camshaft acts on the roller to drive the rocker arm to move.

[0019] To achieve the above objectives, according to a second aspect of the present invention, a method for controlling variable valve lift is provided.

[0020] The variable valve lift control method is based on the aforementioned variable valve lift mechanism; wherein,

[0021] The control method includes the following steps:

[0022] The opening and closing relationship map of the solenoid valve corresponding to the engine speed and torque is calibrated, and the opening and closing relationship map data is written into the control unit; wherein, the opening and closing relationship map is represented as a one-to-one correspondence table between engine speed, torque and solenoid valve opening and closing;

[0023] When the engine is running, the control unit acquires engine speed and torque data, and controls the opening and closing of the solenoid valve according to the opening and closing relationship map.

[0024] Advantages of this invention:

[0025] The variable valve lift mechanism in this invention enables the engine to intake less air at low speeds and more air at high speeds and high loads, thus ensuring complete fuel combustion and reducing fuel consumption and emissions. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0027] Figure 1 A schematic diagram of the structure of the variable valve lift mechanism in the embodiments provided by the present invention. Figure 1 ;

[0028] Figure 2 A schematic diagram of the structure of the variable valve lift mechanism in the embodiments provided by the present invention. Figure 2 ;

[0029] Figure 3 This is a partial cross-sectional schematic diagram of the variable valve lift mechanism in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the rocker arm structure in an embodiment provided by the present invention;

[0031] Figure 5 The control flowchart is shown in the embodiment of the present invention for the control method of variable valve lift.

[0032] In the picture:

[0033] 1. Camshaft; 2. Roller; 3. Roller shaft; 4. Rocker arm; 4-1. Sliding groove; 4-2. Connecting groove; 5. Intake valve; 6. Support body; 7. First elastic element; 8. Slider; 9. Sliding pin; 10. Sliding pin body; 11. Second elastic element; 12. Solenoid valve; 13. First pipe; 14. Second pipe; 15. Check valve; 16. Oil reservoir. Detailed Implementation

[0034] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0035] Figures 1-2 A schematic diagram of the structure of the variable valve lift mechanism in an embodiment of the present invention is shown.

[0036] Figure 3 A cross-sectional schematic diagram of a portion of the structure of the variable valve lift mechanism in an embodiment of the present invention is shown.

[0037] Figure 4 A schematic diagram of the rocker arm 4 in an embodiment of the present invention is shown.

[0038] like Figure 1-3 As shown, the variable valve lift mechanism of the present invention includes a camshaft 1 and a rocker arm assembly with transmission cooperation, as well as an intake valve 5, a sliding assembly and a control unit. The rocker arm assembly includes a rocker arm 4, which includes a first end arm and a second end arm arranged opposite to each other. The intake valve 5 is rotatably connected to the second end arm. The sliding assembly includes a slider 8, which is slidably connected to the first end arm. The control unit includes a sliding pin 9 and a solenoid valve 12. The sliding pin 9 and the slider 8 are independently arranged and transmission cooperation. By controlling the solenoid valve 12 to close, the sliding pin 9 is driven to move. The sliding pin 9 drives the slider 8 to slide to increase the downward pressure of the intake valve 5.

[0039] In an embodiment of the present invention, the intake valve 5 and the slider 8 are respectively disposed at opposite ends of the rocker arm 4. The camshaft 1 drives the rocker arm 4 to move. The rocker arm 4 uses the contact point between the slider 8 and the first end arm as the fulcrum to press the intake valve 5 downward. Since the sliding pin 9 and the slider 8 are independently disposed and driven together, this can be achieved by controlling the opening and closing of the solenoid valve 12: at low speed, the solenoid valve 12 is opened, at which time the sliding pin 9 does not move, the sliding pin 9 and the slider 8 do not contact each other, and no pushing force is applied to the slider 8. The descent amplitude of the intake valve 5 is small, and the intake volume is small. At high speed and high load, the solenoid valve 12 is closed, the sliding pin 9 presses the slider 8 to slide to the right, and the contact fulcrum between the slider 8 and the rocker arm 4 moves to the right. According to the lever principle, when the roller 2 is at the same descent amplitude, the descent amplitude of the rocker arm 4 near the intake valve 5 will be increased, which increases the descent / pressing amplitude of the intake valve 5, increases the lift, and makes the intake volume per unit time larger, and the engine power stronger.

[0040] like Figure 3 and Figure 4 As shown, the first end arm is provided with a long strip-shaped sliding groove 4-1, and the slider 8 is slidably connected to the sliding groove 4-1.

[0041] In an embodiment of the present invention, the length direction of the sliding groove 4-1 extends from the end of the first end arm to the end closer to the second end arm, thereby enabling the slider 8 to slide from the end of the first end arm to the end closer to the second end arm. The contact fulcrum between the slider 8 and the rocker arm 4 changes. For example, if the contact fulcrum moves to the right, according to the lever principle, the descent of the end of the rocker arm 4 connected to the intake valve 5 will increase, thereby increasing the lift.

[0042] like Figure 3 and Figure 4As shown, the second end arm is provided with a connecting groove 4-2, and the end of the intake valve 5 is rotatably connected to the connecting groove 4-2.

[0043] like Figure 2 and Figure 3 As shown, the sliding assembly also includes a support body 6 and a first elastic element 7. The support body 6 has a receiving groove. One end of the slider 8 is slidably connected to the sliding groove 4-1 on the first end arm, and the other end of the slider 8 is slidably connected to the receiving groove. The first elastic element 7 is sandwiched between the slider 8 and the groove wall of the receiving groove, and the first elastic element 7 is opposite to the sliding pin 9. The first elastic element 7 and the sliding pin 9 are respectively placed at opposite ends of the slider 8. The first elastic element 7 is configured to provide a reset force for the slider 8.

[0044] like Figure 3 As shown, a connecting port is provided on the wall of the receiving groove, and one end of the sliding pin 9 extends into the receiving groove through the connecting port to engage with the slider 8 in a transmission manner.

[0045] In an embodiment of the present invention, the communication port can be a through hole or a notch, so that one end of the sliding pin 9 can pass through and extend into the receiving groove.

[0046] like Figure 3 As shown, the control unit also includes a sliding pin 10 and a second elastic element 11. The sliding pin 10 has a communicating oil storage cavity 16 and a mounting cavity inside. The sliding pin 9 is placed in the mounting cavity. One end of the sliding pin 9 is placed at the communication between the oil storage cavity 16 and the mounting cavity and is slidably connected to the cavity wall of the mounting cavity. The other end of the sliding pin 9 is a free end, which extends through the cavity wall of the mounting cavity and is in transmission cooperation with the slider 8. The second elastic element 11 is placed in the mounting cavity and is used to make the free end of the sliding pin 9 move telescopically relative to the mounting cavity.

[0047] In an embodiment of the present invention, when the solenoid valve 12 is closed, the high-pressure oil cannot be discharged through the one-way valve 15. The high-pressure oil in the oil storage chamber 16 presses the sliding pin 9 to slide to the right, and the sliding pin 9 drives the slider 8 to slide to the right. The contact fulcrum between the slider 8 and the first end arm moves to the right, thereby increasing the descent of the intake valve 5 and increasing the intake volume.

[0048] It is worth mentioning that the longitudinal height of one end of the sliding pin 9 is adapted to the longitudinal height of the mounting cavity, and the longitudinal height of the mounting cavity is greater than the longitudinal height of the oil storage cavity 16, so as to form a proper seal on the mounting cavity and prevent the high-pressure oil inside the oil storage cavity 16 from leaking out from the connection between the oil storage cavity 16 and the mounting cavity.

[0049] Figure 3 A sliding pin 9 with a T-shaped structure is shown. A second elastic element 11 is placed in the mounting cavity and sleeved on the sliding pin 9 to provide a force for the sliding pin 9 to reset.

[0050] like Figure 3As shown, the sliding pin body 10 is connected to a first pipe 13 and a second pipe 14 that connect to the oil storage chamber 16. The solenoid valve 12 controls the opening and closing of the second pipe 14. The first pipe 13 is equipped with a one-way valve 15. The one-way valve 15 ensures that the high-pressure oil can only be delivered in one direction.

[0051] like Figure 1 and Figure 2 As shown, the rocker arm assembly also includes a roller 2 and a roller shaft 3. Both the roller 2 and the rocker arm 4 are mounted on the roller shaft 3. The cam on the camshaft 1 acts on the roller 2 to drive the rocker arm 4 to move.

[0052] In an embodiment of the present invention, the rocker arm 4 further includes two sleeve rings connected between the first end arm and the second end arm. The two sleeve rings are arranged side by side, and the two ends of each sleeve ring are respectively connected to the first end arm and the second end arm. There is a gap between the two sleeve rings. The roller shaft 3 passes through the two sleeve rings, and the roller 2 is sleeved on the roller shaft 3. The roller 2 is located in the gap between the two sleeve rings.

[0053] According to a specific embodiment of the present invention, a control method for variable valve lift is also provided, which is based on the above-described variable valve lift mechanism.

[0054] Figure 5 A control flowchart of the control method in an embodiment of the present invention is shown.

[0055] The control method of the present invention includes the following steps:

[0056] 1) Calibrate the solenoid valve opening and closing relationship map corresponding to engine speed and torque, and write the opening and closing relationship map data into the control unit; wherein, the opening and closing relationship map is represented as a one-to-one correspondence table between engine speed, torque and solenoid valve opening and closing.

[0057] In an embodiment of the present invention, performance calibration is first performed to determine when the solenoid valve 12 opens and closes based on the engine speed and torque, and the opening and closing relationship (i.e., map) of each speed, torque and solenoid valve 12 is written into the control unit.

[0058] 2) When the engine is running, the control unit acquires engine speed and torque data, and controls the opening and closing of solenoid valve 12 according to the opening and closing relationship map.

[0059] In an embodiment of the present invention, when the engine is running, the map is first consulted to determine the opening and closing of the solenoid valve 12. At low speed, the solenoid valve 12 is normally open, and high-pressure oil leaks out through the first pipe 13, the sliding pin 10, the second pipe 14, and the solenoid valve 12. At this time, the sliding pin 9 does not move, and the sliding pin 9 and the slider 8 do not contact each other, so no pushing force is applied to the slider 8, the descent of the intake valve 5 is small, and the intake volume is small.

[0060] At high speed and high load, the solenoid valve 12 is closed, and the high-pressure oil cannot be discharged after entering the one-way valve 15. The high-pressure oil presses the sliding pin 9 to slide to the right, and the sliding pin 9 presses the slider 8 to slide to the right. The contact fulcrum of the slider 8 and the rocker arm 4 moves to the right. According to the lever principle, since the roller 2 is at the same downward amplitude, the downward amplitude of the rocker arm 4 near the intake valve 5 will increase.

[0061] It should be noted that the term "comprising" and any variations thereof in the specification and claims of this invention are intended to cover non-exclusive inclusion, for example, including a series of components that are not necessarily limited to those explicitly listed, but may include other components that are not explicitly listed or that are inherent to the component.

[0062] In this invention, the terms "upper," "lower," "bottom," "top," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0063] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0064] Furthermore, the descriptions of "first," "second," etc., involved in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0065] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0066] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A control method for a variable valve lift mechanism, characterized in that, The institutions include: A camshaft (1) and rocker arm assembly with transmission cooperation, the rocker arm assembly including a rocker arm (4), the rocker arm (4) including a first end arm and a second end arm disposed opposite to each other; Intake valve (5), the intake valve (5) is rotatably connected to the second end arm; The sliding component includes a slider (8) which is slidably connected to the first end arm; The control unit includes a sliding pin (9) and a solenoid valve (12). The sliding pin (9) and the slider (8) are independently set and driven together. By controlling the solenoid valve (12) to close, the sliding pin (9) is driven to move. The sliding pin (9) drives the slider (8) to slide to increase the downward pressure of the intake valve (5). The sliding assembly further includes a support body (6) and a first elastic element (7). The support body (6) has a receiving groove. One end of the slider (8) is slidably connected to the first end arm, and the other end of the slider (8) is slidably connected to the receiving groove. The first elastic element (7) is sandwiched between the slider (8) and the groove wall of the receiving groove, and the first elastic element (7) is opposite to the sliding pin (9). The wall of the receiving groove is provided with a communication port, and one end of the sliding pin (9) extends into the receiving groove through the communication port to engage with the slider (8) in a transmission cooperation. The control unit further includes a sliding pin (10) and a second elastic element (11). The sliding pin (10) has a communicating oil storage cavity (16) and a mounting cavity inside. The sliding pin (9) is located in the mounting cavity. One end of the sliding pin (9) is placed at the communication between the oil storage cavity (16) and the mounting cavity and is slidably connected to the cavity wall of the mounting cavity. The other end is a free end and extends through the cavity wall of the mounting cavity to engage with the slider (8) in a transmission cooperation. The second elastic element (11) is placed in the mounting cavity and is used to make the free end of the sliding pin (9) extend and retract relative to the mounting cavity. The control method includes the following steps: The opening and closing relationship map of the solenoid valve corresponding to the engine speed and torque is calibrated, and the opening and closing relationship map data is written into the control unit; wherein, the opening and closing relationship map is represented as a one-to-one correspondence table between engine speed, torque and solenoid valve opening and closing; When the engine is running, the control unit acquires engine speed and torque data, and controls the opening and closing of the solenoid valve according to the opening and closing relationship map.

2. The control method for the variable valve lift mechanism as described in claim 1, characterized in that, The first end arm is provided with a long strip-shaped sliding groove (4-1), and the slider (8) is slidably connected to the sliding groove (4-1).

3. The control method for the variable valve lift mechanism as described in claim 2, characterized in that, The length of the sliding groove (4-1) extends from the end of the first end arm toward the end closer to the second end arm.

4. The control method for the variable valve lift mechanism as described in claim 1, characterized in that, The second end arm is provided with a connecting groove (4-2), and the end of the air intake valve (5) is rotatably connected to the connecting groove (4-2).

5. The control method for the variable valve lift mechanism as described in claim 1, characterized in that, The sliding pin (10) is connected to a first pipe (13) and a second pipe (14) that connect to the oil storage chamber (16). The solenoid valve (12) controls the opening and closing of the second pipe (14). A one-way valve (15) is provided on the first pipe (13).

6. The control method for the variable valve lift mechanism as described in claim 1, characterized in that, The rocker arm assembly also includes a roller (2) and a roller shaft (3). The roller (2) and the rocker arm (4) are both mounted on the roller shaft (3). The cam on the camshaft (1) acts on the roller (2) to drive the rocker arm (4) to move.

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