Variable valve lift structure

Abstract

The utility model relates to the technical field of motorcycle engines, and discloses a variable valve lift structure which comprises a cam shaft assembly, a first air inlet rocker arm, a second air inlet rocker arm, an electromagnetic valve, a rocker arm shaft and an exhaust rocker arm assembly, and the first air inlet rocker arm and the second air inlet rocker arm are connected with a low-lift air inlet convex hull and a high-lift air inlet convex hull on the cam shaft assembly respectively. The first air inlet rocker arm and the second air inlet rocker arm are connected to the rocker arm shaft, the first air inlet rocker arm is connected with the third air inlet rocker arm through the first linkage mechanism to form a complete rocker arm, the second air inlet rocker arm is connected with the third air inlet rocker arm through the second linkage mechanism to form a complete rocker arm, and the third air inlet rocker arm is connected to the rocker arm shaft and used for being connected with an air inlet valve. The electromagnetic valve is of a double-ejector-rod structure, and double ejector rods stretch out and draw back to push the first linkage mechanism and the second linkage mechanism to conduct air valve switching. The bearing strength of the variable valve structure is reduced, the structure is compact, the service life is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of motorcycle engines, and particularly relates to a variable valve lift structure. Background Technique

[0002] Variable Valve Lift (VVL) is an advanced engine technology that allows the opening degree of the valve to be automatically adjusted during the engine operation to meet the requirements of different working conditions, thereby improving the performance and efficiency of the engine. The variable valve lift technology optimizes the intake air volume and intake efficiency of the engine at different speeds and loads by changing the opening degree (i.e., lift) of the valve. This technology helps to improve the low-speed torque, high-speed power, and fuel economy of the engine.

[0003] The variable valve lift technology for automobile engines is mainly a technical system for adjusting the opening angle of the valves of automobile engines. Especially during the operation of the engine, when the valve stroke is high and the cross-sectional area is large, the intake resistance will be reduced. In this state, the high-speed operation of the automobile can be effectively optimized. If the valve is small, problems such as negative pressure in the cylinder will occur during the operation of the automobile. Once the automobile accelerates at this time, a rapid convection of the air flow will be formed, increasing the overall resistance of the vehicle operation, restricting the safe driving of the vehicle, and also causing serious problems in the intake and exhaust links of the automobile valves, resulting in limited safety of the automobile. This requires the use of the variable valve lift technology for automobile engines to ensure the safe speed regulation of the vehicle.

[0004] Chinese patent document CN117685076A discloses a variable valve structure for a motorcycle engine. The engine includes a cylinder block and an intake valve. A rocker shaft and a camshaft are provided in the cylinder block. The variable valve structure includes an intake rocker arm I connected to the rocker shaft. The feature is that the camshaft has an intake cam I and an intake cam II, and the tip of the intake cam II is higher than the tip of the intake cam I. One end of the intake rocker arm I is connected to the intake valve, and the other end abuts against the outer peripheral surface of the intake cam I. An intake rocker arm II that abuts against the outer peripheral surface of the intake cam II and can swing independently relative to the intake rocker arm I is also connected to the rocker shaft. A clutch assembly is also provided on the cylinder block to combine the intake rocker arm I and the intake rocker arm II and make the intake rocker arm I and the intake rocker arm II swing with the same amplitude.

[0005] Chinese Patent Document CN202348362U discloses an engine valve rocker arm. The high- and low-speed intake cam switching control mechanism includes: a piston that can slide up and down within the high-speed intake cam control part. A high-speed intake cam contact block is connected to the lower end of the piston, and a high-speed intake cam contact surface that can contact the high-speed intake cam is provided at the lower end of the high-speed intake cam contact block. A piston guiding inclined surface, a limit card slot, and a piston working plane are also provided on the piston; a pin hole provided within the high-speed intake cam control part; a pin that can slide within the pin hole, and a spring groove Ⅰ is provided at one end of the pin; a pin guiding inclined surface, a limit hook, a pin limiting surface, and a pin working plane are also provided on the pin; a hydraulic pipeline, which is provided at one end of the valve rocker arm close to the rocker shaft and is communicated with the above-mentioned pin hole; an end cover.

[0006] The prior art has the following deficiencies: In the high-speed state, the clutch assembly that combines the intake rocker arm one and the intake rocker arm two and enables the intake rocker arm one and the intake rocker arm two to swing with the same amplitude has high strength requirements for the components of the variable valve structure. After long-term operation, the valve spring in the variable valve structure is prone to damage, affecting the variable valve lift function. Summary of the Invention

[0007] The utility model provides a variable valve lift structure to solve the technical problem that the variable valve structure is prone to damage in the high-speed state. The variable valve lift structure includes a camshaft assembly, an intake rocker arm one, an intake rocker arm two, an electromagnetic valve, a rocker shaft, and an exhaust rocker arm assembly. The intake rocker arm one and the intake rocker arm two are respectively connected to the low-lift intake convex lobe and the high-lift intake convex lobe on the camshaft assembly. The intake rocker arm one and the intake rocker arm two are connected to the rocker shaft. It is characterized in that the intake rocker arm one is connected to the intake rocker arm three through a linkage mechanism one to form a complete rocker arm, the intake rocker arm two is connected to the intake rocker arm three through a linkage mechanism two to form a complete rocker arm, the intake rocker arm three is connected to the rocker shaft, and the intake rocker arm three is used to connect the intake valve. The electromagnetic valve is of a double push rod structure, and the double push rods respectively push the linkage mechanism one and the linkage mechanism two through expansion and contraction for valve switching.

[0008] Further, the linkage mechanism one includes a linkage part one and a linkage pin one. The linkage part one is located on the intake rocker arm one, and a connecting pin hole three is provided on the intake rocker arm three. The linkage pin one is inserted through and connected to the linkage part one and the connecting pin hole three.

[0009] Further, the linkage mechanism two includes a linkage part two and a linkage pin two. The linkage part two is located on the intake rocker arm three, and a connecting pin hole two is provided on the intake rocker arm two. The linkage pin two is inserted through and connected to the linkage part two and the connecting pin hole two.

[0010] To improve the internal structural compactness, the first linkage mechanism and the second linkage mechanism are arranged horizontally offset, so that the operation of each intake rocker arm does not interfere with each other.

[0011] Preferably, a first rocker arm hole and a first roller are provided on the first intake rocker arm, a second rocker arm hole and a second roller are provided on the second intake rocker arm, a third rocker arm hole and an intake valve clearance adjusting screw connection hole are provided on the third intake rocker arm, the rocker shaft is simultaneously connected to the first rocker arm hole, the second rocker arm hole and the third rocker arm hole, and the first roller and the second roller are connected to the low-lift intake lobe and the high-lift intake lobe on the camshaft assembly.

[0012] Furthermore, the solenoid valve is a double push rod structure, namely a first solenoid valve push rod and a second solenoid valve push rod, and the first solenoid valve push rod and the second solenoid valve push rod are of a one-short-and-one-long structure.

[0013] To facilitate resetting, snap rings and return springs are provided inside both the first linkage part and the second linkage part. Steps are provided in the middle of the first linkage pin and the second linkage pin. The snap rings and the return springs are respectively located on both sides of the steps. The return springs are sleeved on the first linkage pin and the second linkage pin. One end of the return spring abuts against the steps of the first linkage pin and the second linkage pin, and the other end abuts against the first linkage part and the second linkage part. The return springs cause the first linkage pin and the second linkage pin to rebound and disengage, and the snap rings are fixed inside the first linkage part and the second linkage part to limit the rebound and detachment of the first linkage pin.

[0014] To prevent the first intake rocker arm and the second intake rocker arm from rotating randomly, a first torsion spring outer sleeve and a first torsion spring are sleeved on one end of the rocker shaft. The first torsion spring abuts against the first intake rocker arm, and the first roller is always in contact with the low-lift intake lobe. A second torsion spring outer sleeve and a second torsion spring are sleeved on the other end of the rocker shaft. The second torsion spring abuts against the second intake rocker arm, and the second roller is always in contact with the high-lift intake lobe.

[0015] Furthermore, wave washers are provided between the first torsion spring and the first intake rocker arm and between the second torsion spring and the second intake rocker arm.

[0016] The utility model has the following beneficial effects:

[0017] 1. In the prior art, at high speeds, two intake rocker arms rotate simultaneously, generating a large inertia during rotation. In the present utility model, a solenoid valve combines a double push rod structure with a double linkage mechanism. When in the low-speed state, linkage mechanism one combines intake rocker arm one and intake rocker arm three to form a complete intake rocker arm, and the linkage pin in linkage mechanism two separates, causing intake rocker arm two to rotate idly. When in the high-speed state, linkage mechanism two combines intake rocker arm two and intake rocker arm three to form a complete intake rocker arm, and the linkage pin in linkage mechanism one separates, causing intake rocker arm one to rotate idly. Whether in the low-speed state or the high-speed state, the actual load-bearing strength of the present utility model is only the rotational strength of one intake rocker arm, reducing the inertia generated by the intake rocker arm in the high-speed operation state, reducing the strength that the variable valve structure needs to bear, increasing the service life, and reducing the maintenance cost.

[0018] 2. In the present utility model, the volume ratio of the intake rocker arm is reduced. Intake rocker arm one, intake rocker arm two, and intake rocker arm three together are equivalent to 1.5 complete intake rocker arms, and the rollers of the intake rocker arms are close to the rollers of the exhaust rocker arms but do not cause any interference, having a compact effect.

[0019] 3. There is a torsion spring on each side of the rocker shaft of the present utility model, which can ensure that the rollers in intake rocker arm one and intake rocker arm two always abut against the convex bumps on the camshaft. Therefore, the variable valve lift structure of the present utility model has good working stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the installation schematic diagram of the variable valve lift structure of the present utility model;

[0021] Figure 2 is the overall structure schematic diagram of the variable valve lift structure of the present utility model;

[0022] Figure 3 is the cross-sectional view of the variable valve lift structure of the present utility model in the low-speed state;

[0023] Figure 4 is the exploded view of the variable valve lift structure of the present utility model;

[0024] Figure 5 is the structure schematic diagram of 3 intake rocker arms;

[0025] Figure 6 is the schematic diagram of intake rocker arm one;

[0026] Figure 7 is the schematic diagram of intake rocker arm two;

[0027] Figure 8 is the schematic diagram of intake rocker arm three;

[0028] Figure 9 is the schematic diagram of the solenoid valve;

[0029] Figure 10 This is a cross-sectional view of the variable valve lift structure of the present utility model in the high lift state. Specific embodiments

[0030] The following is a further detailed description through specific embodiments:

[0031] 1. The reference numerals in the attached drawings of the specification include: camshaft assembly 1, low lift intake lobe 101, high lift intake lobe 102, intake rocker arm 1 2, rocker arm shaft hole 1 201, roller 1 202, intake rocker arm 2 3, connecting pin hole 2 301, rocker arm shaft hole 2 302, roller 2 303, intake rocker arm 3 4, connecting pin hole 3 401, rocker arm shaft hole 3 402, intake valve clearance adjusting screw connection hole 403, solenoid valve 5, solenoid valve push rod 1 501, solenoid valve push rod 2 502, rocker arm shaft 6, rocker arm shaft sleeve 601, exhaust rocker arm assembly 7, linkage mechanism 1 8, linkage part 1 801, linkage pin 1 802, linkage mechanism 2 9, linkage part 2 901, linkage pin 2 902, intake valve clearance adjusting screw 10, snap ring 11, return spring 12, step 13, torsion spring outer sleeve 1 14, torsion spring 1 15, torsion spring outer sleeve 2 16, torsion spring 2 17, wave washer 18.

[0032] Embodiment 1

[0033] As Figures 1-9 shown, a variable valve lift structure includes a camshaft assembly 1, an intake rocker arm 1 2, an intake rocker arm 2 3, an intake rocker arm 3 4, a solenoid valve 5, a rocker arm shaft 6, a rocker arm shaft sleeve 601 and an exhaust rocker arm assembly 7. The intake rocker arm 1 2 and the intake rocker arm 2 3 are not directly connected to the intake valve clearance adjusting screw 10, and the intake rocker arm 3 4 is not directly connected to the lobes on the camshaft assembly 1. The intake rocker arm 1 2 and the intake rocker arm 2 3 are respectively connected to the low lift intake lobe 101 and the high lift intake lobe 102 on the camshaft assembly 1. The intake rocker arm 1 2 and the intake rocker arm 2 3 are connected to the rocker arm shaft sleeve 601 on the rocker arm shaft 6, and the rocker arm shaft sleeve 601 is fixed on the rocker arm shaft 6. The intake rocker arm 1 2 is connected to the intake rocker arm 3 4 through a linkage mechanism 1 8 to form a complete rocker arm, and the intake rocker arm 2 3 is connected to the intake rocker arm 3 4 through a linkage mechanism 2 9 to form a complete rocker arm. The intake rocker arm 3 4 is connected to the rocker arm shaft sleeve 601 on the rocker arm shaft 6, and the intake rocker arm 3 4 is connected to the intake valve clearance adjusting screw 10. The solenoid valve 5 has a double push rod structure, and the double push rods respectively push the linkage mechanism 1 8 and the linkage mechanism 2 9 through expansion and contraction for valve switching.

[0034] The linkage mechanism 8 includes a first linkage part 801 and a first linkage pin 802. The first linkage part 801 is located on the first intake rocker arm 2. A third connecting pin hole 401 is provided on the third intake rocker arm 4. The first linkage pin 802 is inserted through and connected to the first linkage part 801 and the third connecting pin hole 401.

[0035] The linkage mechanism 9 includes a second linkage part 901 and a second linkage pin 902. The second linkage part 901 is located on the third intake rocker arm 4. A second connecting pin hole 301 is provided on the second intake rocker arm 3. The second linkage pin 902 is inserted through and connected to the second linkage part 901 and the second connecting pin hole 301.

[0036] The linkage mechanism 8 and the linkage mechanism 9 are arranged horizontally offset so that the operation of each intake rocker arm does not interfere with each other.

[0037] The solenoid valve 5 has a double push rod structure, namely a first solenoid valve push rod 501 and a second solenoid valve push rod 502. The first solenoid valve push rod 501 pushes the first linkage pin 802 to move axially so that the first intake rocker arm 2 and the third intake rocker arm 4 are interlaced together. The second solenoid valve push rod 502 pushes the second linkage pin 902 to move axially so that the second intake rocker arm 3 and the third intake rocker arm 4 are interlaced together.

[0038] The first solenoid valve push rod 501 is a short solenoid valve push rod, and the second solenoid valve push rod 502 is a long solenoid valve push rod.

[0039] A first rocker arm shaft hole 201 and a first roller 202 are provided on the first intake rocker arm 2. A second rocker arm shaft hole 302 and a second roller 303 are provided on the second intake rocker arm 3. A third rocker arm shaft hole 402 and an intake valve clearance adjusting screw connection hole 403 are provided on the third intake rocker arm 4. The rocker arm shaft 6 is simultaneously connected to the first rocker arm shaft hole 201, the second rocker arm shaft hole 302, and the third rocker arm shaft hole 402 through a rocker arm shaft sleeve 601. The first roller 202 and the second roller 303 are connected to the low-lift intake lobe 101 and the high-lift intake lobe 102 on the camshaft assembly 1. Of course, the intake rocker arm may or may not be provided with rollers, that is, it is a rocker arm of other structural forms.

[0040] The linkage part 1 801 and the linkage part 2 901 are both provided with a retaining ring 11 and a return spring 12, and the middle parts of the linkage pin 1 802 and the linkage pin 2 902 are both provided with a step 13, the retaining ring 11 and the return spring 12 are located on both sides of the step 13 respectively, and the return spring 12 is sleeved on the linkage pin 1 802 and the linkage pin 2 902, one end of the return spring 12 is pressed against the step 13 of the linkage pin 1 802 and the linkage pin 2 902, and the other end is pressed against the linkage part 1 801 and the linkage part 2 901, the return spring 12 rebounds and disengages the linkage pin 1 802 and the linkage pin 2 902, and the retaining ring 11 is fixed in the linkage part 1 801 and the linkage part 2 901 to limit the rebound and detachment of the linkage pin 1 802.

[0041] One end of the rocker shaft 6 is sleeved with a torsion spring sleeve 14 and a torsion spring 15, and the torsion spring 15 is pressed against the intake rocker arm 2, and the roller 202 is always in contact with the low-lift intake convex bump 101. The other end of the rocker shaft 6 is sleeved with a torsion spring sleeve 2 16 and a torsion spring 2 17, and the torsion spring 2 17 is pressed against the intake rocker arm 2 3, and the roller 2 303 is always in contact with the high-lift intake convex bump 102.

[0042] A corrugated gasket 18 is provided between the torsion spring 15 and the intake rocker arm 1 2 and between the torsion spring 2 17 and the intake rocker arm 2 3 .

[0043] like Figure 3 As shown, when the motorcycle engine is in a working state with a low speed or in a stationary or flameout state, the solenoid valve push rod 1 501 pushes the linkage pin 1 802 to make an axial movement so that the intake rocker arm 1 2 and the intake rocker arm 3 4 are interlaced together, and the low-lift intake convex bump 101 and the intake valve clearance adjustment screw 10 work. At this time, the intake rocker arm 1 2 and the intake rocker arm 3 4 rotate freely with the camshaft assembly 1;

[0044] like Figure 10 As shown, when the motorcycle engine is in working condition, it increases from low speed to high speed, and the solenoid valve push rod 2 502 pushes the solenoid valve push rod 2 502 to make axial movement so that the intake rocker arm 2 3 and the intake rocker arm 3 4 are interlaced together. When the solenoid valve 5 senses that the linkage pin 2 902 is correctly inserted into the rocker arm 3, the solenoid valve push rod 1 501 retracts, and the linkage pin 1 802 on the intake rocker arm 1 2 will no longer be interlaced with the intake rocker arm 3 4 under the action of the return spring 12. At this time, the intake rocker arm 1 2 will no longer work, and will be replaced by the roller 2 303 on the intake rocker arm 2 3, which is pressed on the high-lift intake convex bump 102 on the camshaft assembly 1 to link with the intake rocker arm 3 4.

[0045] The installation sequence of the intake variable lift mechanism is as follows: from the chain cavity side in the cylinder head to the spark plug hole side, there are outer torsion spring sleeve - 14, torsion spring - 15, wave washer 18, intake rocker arm - 2, intake rocker arm - 3, intake rocker arm - 2, wave washer 18, torsion spring - 17, outer torsion spring sleeve - 16, solenoid valve push rod - 501, solenoid valve push rod - 502 and solenoid valve 5. The solenoid valve 5 is installed on the cylinder head cover, and a relief should be made on the support part of the camshaft assembly 1 in the cylinder head to avoid interference with the convex part on the cylinder head cover.

[0046] The above are only the embodiments of the present invention. Specific structures and common knowledge such as characteristics that are well-known in the art are not described in detail here. Those of ordinary skill in the art know all the common technical knowledge in the technical field to which the utility model belongs before the application date or the priority date, can know all the existing technologies in this field, and have the ability to apply the conventional experimental means before this date. Those of ordinary skill in the art can, under the inspiration given in this application, combine their own abilities to improve and implement this solution. Some typical well-known structures or well-known methods should not become an obstacle for those of ordinary skill in the art to implement this application. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present invention, which will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. A variable valve lift structure, comprising a camshaft assembly, an intake rocker arm I, an intake rocker arm II, a solenoid valve, a rocker shaft and an exhaust rocker arm assembly. The intake rocker arm I and the intake rocker arm II are respectively connected to a low-lift intake lobe and a high-lift intake lobe on the camshaft assembly. The intake rocker arm I and the intake rocker arm II are connected to the rocker shaft. It is characterized in that, The intake rocker arm 1 is connected to the intake rocker arm 3 through the linkage mechanism 1 to form a complete rocker arm. The intake rocker arm 2 is connected to the intake rocker arm 3 through the linkage mechanism 2 to form a complete rocker arm. The intake rocker arm 3 is connected to the rocker shaft. The intake rocker arm 3 is used to connect the intake valve. The solenoid valve has a double push rod structure. The double push rods respectively push the linkage mechanism 1 and the linkage mechanism 2 through expansion and contraction to perform valve switching.

2. The variable valve lift structure according to claim 1, wherein: The linkage mechanism 1 includes a linkage part 1 and a linkage pin 1. The linkage part 1 is located on the intake rocker arm 1. A connecting pin hole 3 is provided on the intake rocker arm 3. The linkage pin 1 is inserted through and connected to the linkage part 1 and the connecting pin hole 3.

3. The variable valve lift structure according to claim 2, characterized in that: The linkage mechanism 2 includes a linkage part 2 and a linkage pin 2. The linkage part 2 is located on the intake rocker arm 3. A connecting pin hole 2 is provided on the intake rocker arm 2. The linkage pin 2 is inserted through and connected to the linkage part 2 and the connecting pin hole 2.

4. The variable valve lift structure according to claim 1, characterized in that: The linkage mechanism 1 and the linkage mechanism 2 are arranged horizontally staggered.

5. The variable valve lift structure according to any one of claims 2 and 3, characterized in that: The linkage mechanism 1 and the linkage mechanism 2 are arranged horizontally staggered.

6. The variable valve lift structure according to claim 5, wherein: The intake rocker arm 1 is provided with a rocker shaft hole 1 and a roller 1. The intake rocker arm 2 is provided with a rocker shaft hole 2 and a roller 2. The intake rocker arm 3 is provided with a rocker shaft hole 3 and an intake valve clearance adjusting screw connection hole. The rocker shaft is simultaneously connected to the rocker shaft hole 1, the rocker shaft hole 2, and the rocker shaft hole 3. The roller 1 and the roller 2 are connected to the low-lift intake lobe and the high-lift intake lobe on the camshaft assembly.

7. The variable valve lift structure according to claim 6, wherein: The solenoid valve has a double push rod structure, namely a solenoid valve push rod 1 and a solenoid valve push rod 2. The solenoid valve push rod 1 and the solenoid valve push rod 2 have a structure of one short and one long.

8. The variable valve lift structure according to claim 7, wherein: Both the linkage part 1 and the linkage part 2 are provided with snap rings and return springs. Both the middle parts of the linkage pin 1 and the linkage pin 2 are provided with steps. The snap rings and the return springs are respectively located on both sides of the steps. The return springs are sleeved on the linkage pin 1 and the linkage pin 2. One end of the return spring abuts against the steps of the linkage pin 1 and the linkage pin 2, and the other end abuts against the linkage part 1 and the linkage part 2. The return spring rebounds the linkage pin 1 and the linkage pin 2 to disengage. The snap rings are fixed in the linkage part 1 and the linkage part 2 to limit the rebound and falling off of the linkage pin 1.

9. The variable valve lift structure according to any one of claims 6-8, characterized in that: One end of the rocker shaft is sleeved with a torsion spring outer sleeve 1 and a torsion spring 1. The torsion spring 1 abuts against the intake rocker arm 1. The roller 1 is always in contact with the low-lift intake lobe. The other end of the rocker shaft is sleeved with a torsion spring outer sleeve 2 and a torsion spring 2. The torsion spring 2 abuts against the intake rocker arm 2. The roller 2 is always in contact with the high-lift intake lobe.

10. The variable valve lift structure according to claim 9, wherein: Wave washers are provided between the torsion spring 1 and the intake rocker arm 1 and between the torsion spring 2 and the intake rocker arm 2.

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