Variable valve lift structure

Abstract

The invention 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 present application relates to the technical field of motorcycle engines, in particular to a variable valve lift structure. BACKGROUND

[0002] Variable Valve Lift (VVL) is an advanced engine technology that allows the opening degree of the valve to be automatically adjusted during engine operation to adapt to different working condition requirements, thereby improving the performance and efficiency of the engine. Variable Valve Lift technology optimizes the intake 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 of an automobile engine is mainly a technical system for adjusting the angle of the opening size of the valve of the automobile engine. Especially during the operation of the engine, if the valve stroke is high and the cross-sectional area is large, it will cause the intake resistance to decrease. In this state, the high-speed operation of the automobile can be effectively optimized. If the valve is small, the automobile will encounter the problem of negative pressure in the cylinder during operation. Once the automobile accelerates, it will form a rapid convection of air flow, increasing the overall vehicle running resistance and restricting the safe driving of the vehicle. It will also cause serious problems of incoordination in the intake and exhaust links of the automobile valve, limiting the safety of the automobile. Therefore, it is necessary to use the variable valve lift technology of the automobile engine to ensure the safe speed regulation of the vehicle.

[0004] Chinese patent document CN117685076A discloses a variable valve structure of a motorcycle engine, the engine comprising a cylinder body and an intake valve, a rocker shaft and a camshaft are arranged in the cylinder body, the variable valve structure comprises an intake rocker arm one connected to the rocker shaft, characterized in that the camshaft has an intake cam one and an intake cam two, the peach tip part of the intake cam two is higher than the peach tip part of the intake cam one, one end of the intake rocker arm one is connected to the intake valve, and the other end abuts against the outer peripheral surface of the intake cam one, the rocker shaft further connects an intake rocker arm two which abuts against the outer peripheral surface of the intake cam two and can independently swing relative to the intake rocker arm one, and the cylinder body further has a clutch assembly which can combine the intake rocker arm one and the intake rocker arm two and make the intake rocker arm one and the intake rocker arm two swing at the same amplitude.

[0005] The Chinese patent document CN202348362U discloses an engine valve rocker arm, and the high-speed and low-speed intake cam switching control mechanism comprises a piston which can slide up and down in a high-speed intake cam control part, a high-speed intake cam contact block is connected to the lower end of the piston, the lower end of the high-speed intake cam contact block is provided with a high-speed intake cam contact surface which can contact the high-speed intake cam, a piston guide inclined surface, a limiting clamping groove and a piston working plane are further provided on the piston, a pin hole is provided in the high-speed intake cam control part, a pin which can slide in the pin hole is provided, a spring groove I is formed in one end of the pin, a pin guide inclined surface, a limiting hook, a pin limiting surface and a pin working plane are further provided on the pin, a hydraulic pipeline is provided on the valve rocker arm close to the rocker arm rotating shaft and is communicated with the pin hole, and an end cover is provided.

[0006] The prior art has the following disadvantages: in the high-speed state, the clutch assembly which combines the intake rocker arm one and the intake rocker arm two and makes the intake rocker arm one and the intake rocker arm two swing at the same amplitude has high strength requirements for the parts of the variable valve structure, and the valve spring in the variable valve structure is easy to be damaged after long time operation, which affects the variable valve lift function. SUMMARY

[0007] In order to solve the technical problem that the variable valve structure is easy to be damaged in the high-speed state, the application provides a variable valve lift structure, which comprises a camshaft assembly, an intake rocker arm one, an intake rocker arm two, an electromagnetic valve, a rocker arm shaft and an exhaust rocker arm assembly, the intake rocker arm one and the intake rocker arm two are connected with low-lift intake cam and high-lift intake cam on the camshaft assembly respectively, the intake rocker arm one and the intake rocker arm two are connected on the rocker arm shaft, characterized in that the intake rocker arm one is connected with the intake rocker arm three through linkage mechanism one and constitutes a complete rocker arm, the intake rocker arm two is connected with the intake rocker arm three through linkage mechanism two and constitutes a complete rocker arm, the intake rocker arm three is connected on the rocker arm shaft, the intake rocker arm three is used for connecting an intake valve, the electromagnetic valve is a double top rod structure, and the double top rod pushes linkage mechanism one and linkage mechanism two respectively through extension and retraction to switch the valve.

[0008] Further, the linkage mechanism one comprises a linkage part one and a linkage pin one, the linkage part one is located on the intake rocker arm one, the intake rocker arm three is provided with a connecting pin hole three, and the linkage pin one is connected with the linkage part one and the connecting pin hole three.

[0009] Further, the linkage mechanism two comprises a linkage part two and a linkage pin two, the linkage part two is located on the intake rocker arm three, the intake rocker arm two is provided with a connecting pin hole two, and the linkage pin two is connected with the linkage part two and the connecting pin hole two.

[0010] In order to improve the compactness of the internal structure, the linkage mechanism one and the linkage mechanism two are arranged laterally staggered, so that each intake rocker arm operates without interference.

[0011] Preferably, the intake rocker arm one is provided with a rocker shaft hole one and a roller one, the intake rocker arm two is provided with a rocker shaft hole two and a roller two, the intake rocker arm three is provided with a rocker shaft hole three and an intake valve gap adjusting screw connecting hole, the rocker shaft is connected to the rocker shaft hole one, the rocker shaft hole two and the rocker shaft hole three at the same time, and the roller one and the roller two are connected to the low-lift intake cam and the high-lift intake cam on the camshaft assembly.

[0012] Further, the electromagnetic valve is a double-top rod structure, and the electromagnetic valve top rod one and the electromagnetic valve top rod two are a short-long structure.

[0013] In order to facilitate reset, the linkage part one and the linkage part two are both provided with a snap ring and a reset spring, the middle part of the linkage pin one and the linkage pin two is provided with a step, the snap ring and the reset spring are located on both sides of the step respectively, the reset spring is sleeved on the linkage pin one and the linkage pin two, one end of the reset spring is abutted on the step of the linkage pin one and the linkage pin two, and the other end is abutted on the linkage part one and the linkage part two, the reset spring rebounds to disengage the linkage pin one and the linkage pin two, and the snap ring is fixed in the linkage part one and the linkage part two to limit the rebound disengagement of the linkage pin one.

[0014] In order to avoid the rotation of the intake rocker arm one and the intake rocker arm two, the rocker shaft one end is sleeved with a torsional spring outer sleeve one and a torsional spring one, the torsional spring one is abutted on the intake rocker arm one, the roller one is always in contact with the low-lift intake cam, the rocker shaft other end is sleeved with a torsional spring outer sleeve two and a torsional spring two, the torsional spring two is abutted on the intake rocker arm two, and the roller two is always in contact with the high-lift intake cam.

[0015] Further, the torsional spring one and the intake rocker arm one and the torsional spring two and the intake rocker arm two are both provided with a wave washer.

[0016] The present application has the following beneficial effects: 1. In the prior art, the two intake rocker arms rotate simultaneously at high speed, generating large inertia. The present application combines a double top rod structure with a double linkage mechanism through a solenoid valve. When in 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 is separated, so that intake rocker arm two idles. When in 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 is separated, so that intake rocker arm one idles. Whether in low speed state or high speed state, the actual load bearing strength of the present application is only the rotation strength of one intake rocker arm, reducing the inertia generated by the intake rocker arm in high speed state, reducing the load bearing strength required by the variable valve structure, improving the service life and reducing the maintenance cost.

[0017] 2. In the present application, the volume proportion of the intake rocker arm is reduced, and intake rocker arm one, intake rocker arm two and intake rocker arm three together correspond to 1.5 complete intake rocker arms, and the rollers of the intake rocker arms are close to the exhaust rocker arm rollers but do not interfere with each other, having a compact effect.

[0018] 3. The rocker arm shaft of the present application has a torsional spring on each side, which can ensure that the rollers in intake rocker arm one and intake rocker arm two always abut against the convex hull on the camshaft, so that the present variable valve lift structure has good working stability. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the installation schematic diagram of the variable valve lift structure of the present application; Figure 2 is the overall structure schematic diagram of the variable valve lift structure of the present application; Figure 3 is the cross-sectional view of the variable valve lift structure of the present application in low speed state; Figure 4 is the exploded view of the variable valve lift structure of the present application; Figure 5 is the structure schematic diagram of the three intake rocker arms; Figure 6 is the schematic diagram of intake rocker arm one; Figure 7 is the schematic diagram of intake rocker arm two; Figure 8 is the schematic diagram of intake rocker arm three; Figure 9 is the schematic diagram of the solenoid valve; Figure 10 is the cross-sectional view of the variable valve lift structure of the present application in high speed state. DETAILED DESCRIPTION

[0020] The following will be further described in detail through specific embodiments: 1. The reference numerals in the accompanying drawings include: camshaft assembly 1, low-lift intake convex 101, high-lift intake convex 102, intake rocker arm one 2, rocker arm shaft hole one 201, roller one 202, intake rocker arm two 3, connecting pin hole two 301, rocker arm shaft hole two 302, roller two 303, intake rocker arm three 4, connecting pin hole three 401, rocker arm shaft hole three 402, intake valve clearance adjusting screw connecting hole 403, solenoid valve 5, solenoid... Valve top rod 1 501, solenoid valve top rod 2 502, rocker arm shaft 6, rocker arm bushing 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, retaining ring 11, return spring 12, step 13, torsion spring outer sleeve 14, torsion spring 15, torsion spring outer sleeve 2 16, torsion spring 2 17, wave washer 18.

[0021] Example 1 like Figures 1-9 As 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 bushing 601, and an exhaust rocker arm assembly 7. The intake rocker arm 1 2 and 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 camshaft assembly 1. The intake rocker arm 1 2 and intake rocker arm 2 3 are respectively connected to the low-lift intake cam 101 and high-lift intake cam 102 on the camshaft assembly 1. The intake rocker arm 1 2 and intake rocker arm 2 3 are connected... On the rocker arm shaft 6, the rocker arm shaft 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 the linkage mechanism 1 8 to form a complete rocker arm. The intake rocker arm 2 3 is connected to the intake rocker arm 3 4 through the linkage mechanism 2 9 to form a complete rocker arm. The intake rocker arm 3 4 is connected to the rocker arm shaft 6, the rocker arm 3 4 is connected to the intake valve clearance adjusting screw 10. The solenoid valve 5 has a double push rod structure. The double push rods push the linkage mechanism 1 8 and the linkage mechanism 2 9 respectively to switch the valve by extension and retraction.

[0022] The linkage mechanism 8 includes a linkage part 801 and a linkage pin 802. The linkage part 801 is located on the intake rocker arm 2. The intake rocker arm 4 is provided with a connecting pin hole 401. The linkage pin 802 passes through and connects the linkage part 801 and the connecting pin hole 401.

[0023] The linkage mechanism 29 includes a linkage part 2901 and a linkage pin 2902. The linkage part 2901 is located on the air intake rocker arm 34. The air intake rocker arm 23 is provided with a connecting pin hole 2301. The linkage pin 2902 passes through and connects the linkage part 2901 and the connecting pin hole 2301.

[0024] The linkage mechanism 8 and linkage mechanism 9 are horizontally staggered so that the operation of each intake rocker arm does not interfere with each other.

[0025] The solenoid valve 5 has a double-rod structure, consisting of solenoid valve rod 1 501 and solenoid valve rod 2 502. Solenoid valve rod 1 501 pushes the linkage pin 1 802 to move axially, causing the intake rocker arm 1 2 and intake rocker arm 3 4 to be inserted together. Solenoid valve rod 2 502 pushes the linkage pin 2 902 to move axially, causing the intake rocker arm 2 3 and intake rocker arm 3 4 to be inserted together.

[0026] 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.

[0027] The intake rocker arm 1 2 is provided with a rocker arm shaft hole 201 and a roller 202. The intake rocker arm 2 3 is provided with a rocker arm shaft hole 302 and a roller 303. The intake rocker arm 3 4 is provided with a rocker arm shaft hole 402 and an intake valve clearance adjusting screw connection hole 403. The rocker arm shaft 6 is connected to the rocker arm shaft hole 201, the rocker arm shaft hole 302 and the rocker arm shaft hole 402 simultaneously through the rocker arm bushing 601. The roller 202 and the roller 303 are connected to the low lift intake convex 101 and the high lift intake convex 102 on the camshaft assembly 1. Of course, the intake rocker arm can be equipped with rollers or not, which means it is a rocker arm with other structural forms.

[0028] Both linkage part 801 and linkage part 901 are provided with retaining rings 11 and return springs 12. Both linkage pin 802 and linkage pin 902 are provided with steps 13 in the middle. The retaining rings 11 and return springs 12 are located on both sides of the steps 13 respectively. The return springs 12 are sleeved on the linkage pins 802 and 902. One end of the return springs 12 abuts against the steps 13 of the linkage pins 802 and 902, and the other end abuts against the linkage parts 801 and 901. The return springs 12 spring back and disengage from the linkage pins 802 and 902. The retaining rings 11 are fixed in the linkage parts 801 and 901 to limit the springback of the linkage pins 802.

[0029] One end of the rocker arm shaft 6 is fitted with a torsion spring outer sleeve 14 and a torsion spring 15. The torsion spring 15 rests on the intake rocker arm 2. The roller 202 is always in contact with the low-lift intake protrusion 101. The other end of the rocker arm shaft 6 is fitted with a torsion spring outer sleeve 2 16 and a torsion spring 2 17. The torsion spring 2 17 rests on the intake rocker arm 3. The roller 2 303 is always in contact with the high-lift intake protrusion 102.

[0030] Wave-shaped gaskets 18 are provided between the torsion spring 15 and the intake rocker arm 2, and between the torsion spring 17 and the intake rocker arm 3.

[0031] like Figure 3 As shown, when the motorcycle engine is in a low-speed working state, or stationary or off state, the solenoid valve push rod 501 pushes the linkage pin 802 to move axially, so that the intake rocker arm 2 and the intake rocker arm 3 4 are inserted together. The low-lift intake convex 101 and the intake valve clearance adjusting screw 10 are working. At this time, the intake rocker arm 2 and the intake rocker arm 3 4 rotate freely with the camshaft assembly 1. like Figure 10 As shown, when the motorcycle engine is in operation, as it accelerates from low to high speed, the solenoid valve push rod 502 pushes the solenoid valve push rod 502 to move axially, causing the intake rocker arm 3 and the intake rocker arm 4 to engage. When the solenoid valve 5 senses that the linkage pin 902 is correctly inserted into the rocker arm 3, the solenoid valve push rod 501 retracts. Under the action of the return spring 12, the linkage pin 802 on the intake rocker arm 2 will no longer engage with the intake rocker arm 4. At this time, the intake rocker arm 2 will no longer function. Instead, the roller 303 on the intake rocker arm 3 presses against the high-lift intake convex 102 on the camshaft assembly 1, thus engaging with the intake rocker arm 4.

[0032] 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, torsion spring outer sleeve 14, torsion spring 15, wave plate 18, intake rocker arm 12, intake rocker arm 34, intake rocker arm 23, wave plate 18, torsion spring 27, torsion spring outer sleeve 26, solenoid valve push rod 1501, solenoid valve push rod 2502, and solenoid valve 5. Solenoid valve 5 is installed on the cylinder head cover, and the support portion of the camshaft assembly 1 on the cylinder head must be spaced out to avoid interference with the protrusions on the cylinder head.

[0033] The above-mentioned are only embodiments of the present application, and the common knowledge of the specific structure and characteristics in the scheme is not described too much herein. The ordinary skilled person in the art knows all the ordinary technical knowledge in the field of the present application before the application date or the priority date, can know all the prior art in the field, and has the ability to apply the conventional experimental means before that date. The ordinary skilled person in the art can perfect and implement the present scheme under the guidance of the present application, combined with their own ability. Some typical known structures or known methods should not be an obstacle for the ordinary skilled person in the art to implement the present application. It should be pointed out that, for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application. The protection scope of the present application should be subject to the content of its claims, and the specific implementation mode and the like in the specification can be used to explain the content of the claims.

Claims

1. A variable valve lift structure, comprising a camshaft assembly, an intake rocker arm one, an intake rocker arm two, a solenoid valve, a rocker arm shaft, and an exhaust rocker arm assembly, wherein the intake rocker arm one and the intake rocker arm two are respectively connected to a low-lift intake cam and a high-lift intake cam on the camshaft assembly, and the intake rocker arm one and the intake rocker arm two are connected to the rocker arm shaft, characterized in that, The intake rocker arm one is connected to the intake rocker arm three through the linkage mechanism one to form a complete rocker arm. The intake rocker arm two is connected to the intake rocker arm three through the linkage mechanism two to form a complete rocker arm. The intake rocker arm three is connected to the rocker arm shaft. The intake rocker arm three is used to connect the intake valve. The solenoid valve has a double push rod structure. The double push rods push the linkage mechanism one and the linkage mechanism two to switch the valve by extension and retraction.

2. The variable valve lift structure according to claim 1, characterized in that: The linkage mechanism includes a linkage part and a linkage pin. The linkage part is located on the intake rocker arm. The intake rocker arm is provided with a connecting pin hole. The linkage pin connects the linkage part and the connecting pin hole.

3. The variable valve lift structure according to claim 2, characterized in that: The second linkage mechanism includes a second linkage part and a second linkage pin. The second linkage part is located on the third air intake rocker arm. The second air intake rocker arm is provided with a second connecting pin hole. The second linkage pin passes through and connects the second linkage part and the second connecting pin hole.

4. The variable valve lift structure according to any one of claims 1-3, characterized in that: The first linkage mechanism and the second linkage mechanism are arranged laterally offset.

5. The variable valve lift structure according to claim 4, characterized in that: The first intake rocker arm is provided with a rocker arm shaft hole and a roller. The second intake rocker arm is provided with a rocker arm shaft hole and a roller. The third intake rocker arm is provided with a rocker arm shaft hole and an intake valve clearance adjusting screw connection hole. The rocker arm shaft is simultaneously connected to the first rocker arm shaft hole, the second rocker arm shaft hole, and the third rocker arm shaft hole. The first roller and the second roller are connected to the low-lift intake cam and the high-lift intake cam on the camshaft assembly.

6. The variable valve lift structure according to claim 5, characterized in that: The solenoid valve has a double-rod structure, consisting of solenoid valve rod one and solenoid valve rod two, with one rod being short and the other long.

7. The variable valve lift structure according to claim 6, characterized in that: Both linkage part one and linkage part two are provided with a retaining ring and a return spring. Both linkage pin one and linkage pin two have a step in the middle. The retaining ring and return spring are located on both sides of the step respectively. The return spring is sleeved on linkage pin one and linkage pin two. One end of the return spring abuts on the step of linkage pin one and linkage pin two, and the other end abuts on linkage part one and linkage part two. The return spring rebounds and disengages from linkage pin one and linkage pin two. The retaining ring is fixed in linkage part one and linkage part two to limit the rebound and disengagement of linkage pin one.

8. The variable valve lift structure according to any one of claims 5-7, characterized in that: One end of the rocker arm shaft is fitted with a torsion spring outer sleeve and a torsion spring, the torsion spring abutting against the intake rocker arm, and the roller is always in contact with the low-lift intake convexity. The other end of the rocker arm shaft is fitted with a torsion spring outer sleeve and a torsion spring, the torsion spring abutting against the intake rocker arm, and the roller is always in contact with the high-lift intake convexity.

9. The variable valve lift structure according to claim 8, characterized in that: Wave-shaped gaskets 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.

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