Variable valve timing and lifting device of marine four-stroke engine

Abstract

The utility model relates to the technical field of marine engines, and discloses a variable valve timing and lifting device of a marine four-stroke engine, which comprises a rocker arm and a cam, a shaft hole connected with a fixed rotating shaft is arranged at one end of the rocker arm, a driving ring is arranged between the fixed rotating shaft and the rocker arm, and a step groove is arranged in the middle of the rocker arm. A step groove is formed in the rocker arm, a roller control arm is arranged in the step groove, a roller is arranged in the roller control arm, the roller control arm is connected with the driving ring, the driving ring can drive the roller control arm to move back and forth in the step groove, and the cam is located above the rocker arm and makes contact with the roller in the step groove of the rocker arm. The driving device is additionally arranged on the roller on the rocker arm of the valve mechanism of the four-stroke engine, so that the position of the roller relative to the cam is variable, the function that the phase of the valve mechanism of the engine is variable is achieved, the output characteristic of the engine can be effectively improved, the fuel economy is improved, and the system is simple and compact in structure and convenient to maintain.

Description

Technical Field

[0001] The utility model relates to the technical field of marine engines, in particular to a variable valve timing and lift device for a marine four-stroke engine. Background Art

[0002] The intake and exhaust systems of a four-stroke engine are core components that affect the performance of the entire engine. Different engine speeds require different valve timings. When the engine speed changes, the intake air flow rate and the exhaust air flow rate during the forced exhaust period also change accordingly. The effect of using air flow inertia to increase intake and promote exhaust during the late valve closing period will be different.

[0003] For different high-speed ranges, the valve opening time is short, and a larger valve opening is needed to compensate for the deficiency of intake and exhaust. The valve timing of a four-stroke engine should increase according to the intake retardation angle and valve overlap angle as the engine speed increases. Therefore, how to accurately change the timing and lift of the exhaust mechanism is a more important issue. Utility Model Content

[0004] The technical problem to be solved by the utility model is how to accurately change the timing and lift of the scheduling mechanism.

[0005] In order to solve the above technical problems, the technical solution of the utility model is to provide a variable valve timing and lift device for a marine four-stroke engine, including a rocker arm and a cam, one end of the rocker arm is provided with an axial hole connected to a fixed rotating shaft, a driving ring is provided between the fixed rotating shaft and the rocker arm, a step groove is provided in the middle of the rocker arm, a roller control arm is provided in the step groove, a roller is provided inside the roller control arm, the axis of the roller is parallel to the axis of the fixed rotating shaft, the roller control arm is connected to the driving ring, the driving ring can drive the roller control arm to move back and forth in the step groove, and the cam is located above the rocker arm and contacts with the roller in the step groove of the rocker arm.

[0006] Optionally, the roller control arm is a square frame structure, a pin is provided at the center of the roller, and rotating shaft holes for mounting the roller are provided on the roller control arms on both sides of the roller.

[0007] Optionally, a slide groove is provided on the side of the rocker arm, and the pin shaft of the roller passes through the shaft hole and extends into the slide groove, and can move along the slide groove.

[0008] Optionally, a columnar piston and a spring base are respectively provided on both sides of the outside of the roller control arm perpendicular to the roller axis, the columnar piston is connected to the drive ring, a return spring is connected to the spring base, and the other end of the return spring is fixed to the rocker arm.

[0009] Optionally, the drive ring is sleeved on a fixed rotating shaft, a piston block is provided on the outer side of the drive ring, an oil chamber is provided inside the piston block, the oil chamber passes through the piston block and the drive ring where the piston block is located, and the columnar piston is inserted into the oil chamber from the outside of the piston block.

[0010] Optionally, a servo oil pipeline is provided in the fixed rotating shaft, an opening is provided on the fixed rotating shaft, and the servo oil pipeline is communicated with the oil chamber through the opening.

[0011] Optionally, a sealing ring is provided between the columnar piston and the oil chamber.

[0012] In summary, the utility model adds a driving device to the roller on the rocker arm of the valve mechanism of a four-stroke engine so that the position of the roller relative to the cam is variable, thereby realizing the function of variable phase of the engine valve mechanism. The function of stepless adjustment of the phase of the valve mechanism can be achieved by adjusting the servo oil pressure. The same hydraulic system can control multiple groups of valves, which can effectively improve the output characteristics of the engine and improve fuel economy. The system structure is simple and compact and easy to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0014] Figure 2 This is a schematic diagram of the cross-sectional structure of the overall structure of the utility model;

[0015] Figure 3 This is a schematic diagram of the rocker arm structure of the utility model;

[0016] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure at AA in the middle;

[0017] Figure 5 This is a schematic diagram of the structure of the drive ring of the utility model;

[0018] Figure 6 This is a schematic diagram of the structure of the roller control arm of the utility model;

[0019] Figure 7 for Figure 6 Schematic diagram of the cross-section at AA in the middle;

[0020] In the figure: 1. rocker arm; 2. cam; 3. fixed shaft; 5. drive ring; 6. piston block; 7. oil chamber; 8. roller control arm; 9. roller; 10. shaft hole; 11. cylindrical piston; 12. spring base; 13. return spring; 14. slide groove. DETAILED DESCRIPTION

[0021] The following combination Figure 1-7 The utility model is described in further detail.

[0022] The utility model discloses a variable valve timing and lift device for a marine four-stroke engine, referring to Figure 1-4 , including a rocker arm 1 and a cam 2, an axial hole connected to a fixed rotating shaft 3 is provided at one end of the rocker arm 1, a driving ring 5 is provided between the fixed rotating shaft 3 and the rocker arm 1, a step groove is provided in the middle of the rocker arm 1, a roller control arm 8 is provided in the step groove, a roller 9 is provided inside the roller control arm 8, the axis of the roller 9 is parallel to the axis of the fixed rotating shaft 3, the roller control arm 8 is connected to the driving ring 5, the driving ring 5 can drive the roller control arm 8 to move back and forth in the step groove, the cam 2 is located above the rocker arm 1, and contacts with the roller 9 in the step groove of the rocker arm 1.

[0023] In a further embodiment, the roller control arm 8 is a square structure, a pin is provided at the center of the roller 9, a rotating shaft hole 10 for installing the roller 9 is provided on the roller control arm 8 on both sides of the roller 9, a slide groove 14 is provided on the side of the rocker arm 1, the pin of the roller 9 passes through the rotating shaft hole 10 and extends into the slide groove 14, and can move along the slide groove 14.

[0024] In a further embodiment, referring to Figure 5 The drive ring 5 is sleeved on the fixed shaft 3, a piston block 6 is provided on the outer side of the drive ring 5, an oil chamber 7 is provided in the piston block 6, the oil chamber 7 penetrates the piston block 6 and the drive ring 5 where the piston block 6 is located, a servo oil pipeline is provided in the fixed shaft 3, an opening is provided on the fixed shaft 3, and the servo oil pipeline communicates with the oil chamber 7 through the opening; refer to Figure 6 and Figure 7 A columnar piston 11 and a spring base 12 are respectively provided on both sides of the outside of the roller control arm 8 perpendicular to the axis of the roller 9. The columnar piston 11 is connected to the drive ring 5. A return spring 13 is connected to the spring base 12. The other end of the return spring 13 is fixed on the rocker arm 1. The columnar piston 11 is inserted into the oil chamber 7 from the outside of the piston block 6. A sealing ring is provided between the columnar piston 11 and the oil chamber 7.

[0025] When the utility model is in use, the whole system is controlled by servo oil, the roller 9 is fixed in the slide groove 14 on the rocker arm 1 through the pin shaft, and the end of the rocker arm 1 not connected to the fixed shaft 3 is in contact with the valve stem. Under the action of the cam 2, the rocker arm 1 swings downward, pressing the valve stem downward to open the valve;

[0026] When the engine is in the starting and idling state, the roller 9 is located at the initial end of the slide groove 14. When the engine speed increases, the valve retardation angle needs to be increased. The system is pressurized by the hydraulic oil pump, and the servo oil enters the oil chamber 7 of the rocker arm 1 drive ring 5 through the servo oil pipeline in the fixed shaft 3 and the opening on the fixed shaft 3, pushing the cylindrical piston 11 in the drive ring 5 to move forward, and the phase of the valve mechanism changes accordingly. When the valve retardation angle needs to be reduced, the servo oil pressure is reduced. With the assistance of the return spring 13, the roller 9 moves backward, and the phase changes accordingly, thereby ensuring the operating performance of the adapted four-stroke engine.

[0027] The utility model increases the driving mechanism of the roller 9 on the valve rocker arm so that the relative position of the roller 9 can be changed, thereby realizing the function of variable phase of the engine valve mechanism. The control principle of the system is simple, and the function of stepless adjustment of the phase of the valve mechanism can be realized by adjusting the servo oil pressure. The same set of hydraulic system can control multiple groups of valves, which can effectively improve the output characteristics of the engine and improve fuel economy. The system structure is simple and compact and easy to maintain.

[0028] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A variable valve timing and lift device for a marine four-stroke engine, characterized in that: The invention comprises a rocker arm (1) and a cam (2), wherein one end of the rocker arm (1) is provided with an axial hole connected to a fixed rotating shaft (3), a driving ring (5) is provided between the fixed rotating shaft (3) and the rocker arm (1), a step groove is provided in the middle of the rocker arm (1), a roller control arm (8) is provided in the step groove, a roller (9) is provided inside the roller control arm (8), the axis of the roller (9) is parallel to the axis of the fixed rotating shaft (3), the roller control arm (8) is connected to the driving ring (5), the driving ring (5) can drive the roller control arm (8) to move forward and backward in the step groove, and the cam (2) is located above the rocker arm (1) and contacts the roller (9) in the step groove of the rocker arm (1).

2. The variable valve timing and lift device for a marine four-stroke engine according to claim 1, characterized in that: The roller control arm (8) is a square frame structure. A pin is provided at the center of the roller (9). The roller control arms (8) on both sides of the roller (9) are provided with rotating shaft holes (10) for installing the roller (9).

3. The variable valve timing and lift device for a marine four-stroke engine according to claim 2, characterized in that: A slide groove (14) is provided on the side of the rocker arm (1), and the pin shaft of the roller (9) passes through the rotating shaft hole (10) and extends into the slide groove (14), and can move along the slide groove (14).

4. The variable valve timing and lift device for a marine four-stroke engine according to claim 1, characterized in that: The roller control arm (8) is provided with a columnar piston (11) and a spring base (12) on both sides of the roller control arm (8) perpendicular to the axis of the roller (9), the columnar piston (11) is connected to the drive ring (5), and the spring base (12) is connected to a return spring (13), and the other end of the return spring (13) is fixed to the rocker arm (1).

5. The variable valve timing and lift device for a marine four-stroke engine according to claim 4, characterized in that: The driving ring (5) is sleeved on the fixed rotating shaft (3), a piston block (6) is arranged on the outer side of the driving ring (5), an oil chamber (7) is arranged inside the piston block (6), the oil chamber (7) penetrates the piston block (6) and the driving ring (5) where the piston block (6) is located, and the columnar piston (11) is inserted into the oil chamber (7) from the outside of the piston block (6).

6. The variable valve timing and lift device for a marine four-stroke engine according to claim 5, characterized in that: A servo oil pipeline is provided in the fixed rotating shaft (3), an opening is provided on the fixed rotating shaft (3), and the servo oil pipeline is communicated with the oil chamber (7) through the opening.

7. The variable valve timing and lift device for a marine four-stroke engine according to claim 5, characterized in that: A sealing ring is provided between the columnar piston (11) and the oil chamber (7).

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