CN117685076A - Variable valve structure of motorcycle engine - Google Patents

Abstract

The invention provides a variable valve structure of a motorcycle engine, and belongs to the technical field of motorcycles. The variable valve structure solves the problem that the variable valve structure of the existing motorcycle engine is difficult to process. The variable valve structure of the motorcycle engine comprises a cylinder body and an air inlet valve, wherein a rocker arm shaft and a cam shaft are arranged in the cylinder body, the variable valve structure comprises an air inlet rocker arm I connected to the rocker arm shaft, the cam shaft is provided with an air inlet cam I and an air inlet cam II, one end of the air inlet rocker arm I is connected with the air inlet valve, the other end of the air inlet rocker arm I is propped against the outer peripheral surface of the air inlet cam I, the rocker arm shaft is connected with an air inlet rocker arm II which is propped against the outer peripheral surface of the air inlet cam and can swing independently relative to the air inlet rocker arm I, and the cylinder body is also provided with a clutch assembly which can combine the air inlet rocker arm I with the air inlet rocker arm II and enable the air inlet rocker arm I and the air inlet rocker arm II to swing in the same amplitude. The invention can improve the reliability of the variable valve structure and reduce the processing difficulty.

Description

Variable valve structure of motorcycle engine

Technical Field

The invention belongs to the technical field of motorcycles, and relates to a variable valve structure of a motorcycle engine.

Background

The engine during operation bent axle can drive the camshaft rotation, the cam has been linked firmly on the camshaft, this cam offsets with rocking arm one end, pivoted cam can drive the valve and open and shut, the cam includes base circle portion and peach point promptly, base circle portion refers to the cam upper outer wheel and personally submits cylindric part, and the peach point is the part of protruding base circle portion on the cam, the valve is in the closed condition when rocking arm and base circle portion are supported, and the valve is opened when peach point and rocking arm are supported, the size of above-mentioned valve opening is fixed, the valve lift is fixed promptly, and the rotational speed of engine can change, increase to the demand of air input when the rotational speed of engine rises, the fixed engine of valve lift will lead to gas burning inadequately, influence emission and fuel economy.

In view of the above, variable valve structures have been derived from engines. Because the lift size of the intake valve is determined by the shape of the cam on the cam shaft, the conventional variable valve structure on the motorcycle at present commonly adopts the arrangement of two intake cams with different profiles on the cam shaft assembly, and the two intake cams with different profiles are switched to be respectively contacted with the rocker arm of the intake valve by the movement of the position of the intake cam so as to change the action gesture of the rocker arm of the intake valve and further change the air inflow. The two-step adjustable valve lift device (application number: 201711169541.7) of the engine disclosed in the patent document is characterized in that a cam shaft sleeve is sleeved on a cam shaft, a high-speed cam and a low-speed cam are fixedly connected to the cam shaft sleeve, and the cam shaft sleeve is driven to axially move by a control needle valve, so that the high-speed cam and the low-speed cam are mutually switched, and the lift of an intake valve is variable. This type of variable valve structure has some disadvantages: the cam sleeve is fixed relative to the cam shaft in the circumferential direction and axially moves, and the cam sleeve is required to have high machining precision to ensure that the cam sleeve is stably in sliding fit with the cam shaft. However, since the high-speed cam and the low-speed cam of the camshaft assembly are subjected to high load and high pressure during the operation of the engine, and undergo millions of reciprocating movements during the operation of the engine, in order to ensure the reliability and durability of the camshaft assembly, the cam sleeve, the high-speed cam and the low-speed cam are all made of materials having high strength, which greatly increases the difficulty of machining the camshaft assembly, makes the cutting and machining of the camshaft assembly more difficult, and therefore, it is often necessary to provide high-end fine machining equipment, resulting in high machining costs.

In addition, there is a conventional variable valve lift device (application number: 201620498502.6) for a tappet engine of a motorcycle, in which a high-speed cam slider overcomes the urging force of a slider positioning spring when the engine of the motorcycle is running at a high speed, the high-speed cam slider is biased upward, a centrifugal block rotates to a certain extent against the urging force of the centrifugal block spring and drives a high-speed rotating shaft to rotate, and the high-speed rotating shaft is used to push the high-speed cam slider to bias upward, at this time the high-speed cam slider drives a rocker arm to rotate, so that the exhaust valve and the intake valve can be lifted. In the actual use process of the variable valve structure, the variable valve structure has some defects: the radial displacement of the high-speed cam slider is influenced by centrifugal force, a slider positioning spring and a centrifugal block spring, however, due to the extension of the service time or other factors, the pretightening force of the spring may be changed, the elasticity of the spring may become unstable, if the pretightening force is changed, the restoring force of the high-speed cam slider and the centrifugal block may also be influenced, the high-speed cam slider may not be restored in place, the condition of the low-speed cam surface is also protruded after the restoring, the valve lift is abnormal, and the reliability of the variable valve structure is influenced.

Disclosure of Invention

The invention aims at solving the problems in the prior art and provides a variable valve structure of a motorcycle engine, which can improve the reliability of the variable valve structure and reduce the processing difficulty.

The aim of the invention can be achieved by the following technical scheme: the utility model provides a variable valve structure of motorcycle engine, the engine includes cylinder body and intake valve, be equipped with rocking arm axle and camshaft in the cylinder body, variable valve structure includes the intake rocker arm that connects on the rocking arm axle, its characterized in that, have intake cam I and intake cam II on the camshaft, the peach point portion of intake cam II is higher than the peach point portion of intake cam I, intake rocker arm I's one end is connected with the intake valve, and the other end supports and leans on intake cam I's outer peripheral face, still be connected with on the rocking arm axle and support and lean on intake rocker arm II on the outer peripheral face of intake cam and can independently swing relative to intake rocker arm I, still be equipped with on the cylinder body and can combine intake rocker arm I and intake rocker arm two and make intake rocker arm II carry out the clutch pack of swing with the same range with intake rocker arm I.

When the motorcycle runs at a low speed and the engine is at a low rotation speed, the clutch assembly is in a separation state, so that the first air inlet rocker arm and the second air inlet rocker arm swing independently, at the moment, the lift of the air inlet valve is controlled by the first air inlet rocker arm, and the second air inlet rocker arm is not abutted against the air inlet valve, so that the lift of the air inlet valve is not influenced by the action of the second air inlet rocker arm. And because the peach point part of the first air inlet cam is lower, the lift of the air inlet valve is smaller in the process, and the air inflow is smaller. When the motorcycle runs at a high speed and the engine is at a high rotation speed, the clutch assembly is switched to a combined state, so that the first air inlet rocker arm and the second air inlet rocker arm are combined, the second air inlet rocker arm swings with the first air inlet rocker arm in the same amplitude, and the second air inlet rocker arm abuts against the outer peripheral surface of the second air inlet cam and the peach point part of the second air inlet cam is higher than the peach point part of the first air inlet cam, so that the swing amplitude of the first air inlet rocker arm is increased to be the same as that of the second air inlet rocker arm, the lift of the air inlet valve is increased, the air inlet amount is increased, the combustion of the engine is ensured to be more sufficient, the emission is reduced, and the performance of the engine is optimized.

This variable valve structure is through increasing the unique design of intake rocker arm two and separation and reunion subassembly, satisfies the design requirement of variable valve lift, in this design, need not to process complicated special-shaped surface at the camshaft surface and realizes the switching of intake valve lift, consequently can avoid too complicated shape to make the condition that the process of camshaft cutting and processing is more difficult, and then reduces the processing cost of camshaft subassembly.

In addition, in the design, the positions of the first air inlet cam and the second air inlet cam do not need to be changed relative to the cam shaft, and the first air inlet cam and the second air inlet cam can be integrally formed with the cam shaft, so that the change amplitude of the valve lift can be kept consistent all the time even if the motorcycle is driven for a long time when the clutch assembly is switched between the clutch state and the combination state, and the condition that the valve lift is abnormal due to the fact that the high-speed cam sliding block is not reset in place after the service time of the variable valve lift device (application number: 201620498502.6) of the tappet type engine of the motorcycle in the background art is prolonged can not occur, and therefore the variable valve structure has good reliability and working stability.

In the variable valve structure of the motorcycle engine, the first linkage part is arranged at the top of the first air inlet rocker arm, the second linkage part is arranged at the top of the second air inlet rocker arm, the clutch assembly comprises a driving piece and a linkage pin which is arranged in parallel with the cam shaft, the linkage pin axially slides and penetrates through the second linkage part, a pin hole matched with the outer diameter of the linkage pin is formed in the first linkage part, and the driving piece can push the linkage pin to move so that one end of the linkage pin extends into the pin hole to enable the first air inlet rocker arm to be combined with the second air inlet rocker arm. The linkage pin axially slides and passes through the second linkage part, so that the linkage pin can stably axially move. When the rotation speed of the engine is increased, the driving piece pushes the linkage pin, when the linkage pin is aligned with the pin hole, the linkage pin can extend into the pin hole, the linkage pin is still kept in the pin hole by the pushing force of the driving piece, and at the moment, the first air inlet rocker arm and the second air inlet rocker arm are combined, so that the second air inlet rocker arm swings with the first air inlet rocker arm with the same swing amplitude, the lift of the air inlet valve is increased, and the air inflow is increased. The clutch component mainly realizes the clutch function of the clutch component through the improvement of the structures of the first air inlet rocker arm and the second air inlet rocker arm, and does not need to improve the structure of the camshaft component with higher strength, so that the manufacturing and processing difficulty and the processing cost can be reduced.

In the variable valve structure of the motorcycle engine, the second air inlet rocker arm is further provided with a reset spring which can drive the linkage pin to deviate from the pin hole so as to enable the first air inlet rocker arm and the second air inlet rocker arm to swing independently. When the rotation speed of the engine is reduced, the driving piece retreats to loosen the linkage pin, the linkage pin is separated from the pin hole under the action of the reset spring, at the moment, the first air inlet rocker arm and the second air inlet rocker arm swing independently, the lift of the air inlet valve is reduced, and the air inflow is reduced. The reset spring is utilized to realize the reset of the linkage pin, and the device has the advantages of good reliability and low cost.

In the variable valve structure of the motorcycle engine, the opposite end surfaces of the first linkage part and the second linkage part are planes, and the first linkage part and the second linkage part are close to or abutted against each other. The structure can ensure that the first linkage part and the second linkage part are close to each other, so that the linkage pin can stably and smoothly extend into or separate from the pin hole, and the running stability and reliability of the variable valve structure are improved.

In the variable valve structure of the motorcycle engine, one end of the linkage pin, which can extend into the pin hole, is the front end, the other end is the rear end, the driving piece is an electromagnet fixedly connected to the cylinder body, a driving shaft is coaxially arranged between the driving piece and the linkage pin, one end face of the driving shaft abuts against the rear end face of the linkage pin, and the driving piece can push the other end face of the driving shaft and drive the driving shaft to axially move. The electromagnet is the prior art and can be directly purchased in the market, wherein the electromagnet generates a magnetic field when current passes through a coil of the electromagnet, and the driving shaft is driven to move by attraction or repulsion of magnetic force. The electromagnet is adopted to drive the linkage pin to move, so that the device has the advantages of high efficiency and good reliability.

In the variable valve structure of the motorcycle engine, the second linkage part is sleeve-shaped, the second linkage part is internally provided with a mounting hole axially arranged along the second linkage part, the linkage pin is arranged in the mounting hole, the outer wall of the linkage pin is provided with a guide convex edge which is circumferentially arranged and is in sliding fit with the inner wall of the mounting hole, the reset spring is sleeved on the linkage rod, and two ends of the reset spring respectively abut against the guide convex edge and the inner wall of the mounting hole. The sleeve-shaped linkage part II is convenient to manufacture, and the stable axial sliding of the linkage pin can be ensured through the mounting hole of the linkage part II, so that the running stability and reliability of the clutch assembly are improved. The two ends of the return spring are respectively abutted against the guide convex edge and the inner wall of the mounting hole, so that the linkage pin can be smoothly separated from the pin hole under the action of the return spring.

In the variable valve structure of the motorcycle engine, the first air intake rocker arm is provided with the first rocker arm hole, the second air intake rocker arm is provided with the second rocker arm hole, the rocker arm shaft respectively penetrates through the first rocker arm hole and the first rocker arm hole, the end face of the first air intake rocker arm, which faces the second air intake rocker arm, is provided with a first matching plane arranged around the first rocker arm hole, the end face of the second air intake rocker arm, which faces the first air intake rocker arm, is provided with a second matching plane arranged around the second rocker arm hole, and the first matching plane and the second matching plane are abutted. The first air inlet rocker arm and the second air inlet rocker arm are respectively sleeved on the rocker arm shaft through the first rocker arm hole and the second rocker arm hole, so that the first air inlet rocker arm and the second air inlet rocker arm are convenient to install and good in installation stability. Through setting up cooperation plane one and cooperation plane two and making both paste mutually, can promote the operation precision of intake rocking arm one and intake rocking arm two, avoid intake rocking arm one or intake rocking arm two operation precision to reduce and arouse that the mounted position appears deviating, linkage round pin and pinhole concentricity reduce the condition, and then avoid appearing the linkage round pin and be difficult to stretch into the condition of pinhole to guarantee that this variable valve structure has higher operating stability and reliability.

In the variable valve structure of the motorcycle engine, the first linkage part is arranged at the top of the first inlet rocker arm, the second linkage part is arranged at the top of the second inlet rocker arm, the clutch assembly comprises a linkage pin which is parallel to the cam shaft and an electric push rod which is fixedly connected to the cylinder body, the linkage pin axially slides and penetrates through the second linkage part, a pin hole matched with the outer diameter of the linkage pin is formed in the first linkage part, the rear end of the linkage pin extends out of the second linkage part, the rear end of the linkage pin is provided with a bending part, the bending part is connected with a tension spring which can drive the linkage pin to axially move and enable the front end of the linkage pin to extend into the pin hole, the electric push rod is provided with a telescopic rod which is parallel to the linkage pin and can axially stretch out and draw the linkage pin out of the pin hole, and the end face of the telescopic rod is propped against the bending part.

The electric push rod is in the prior art and can be directly purchased in the market, and the principle is that the rotary motion of a motor is changed into linear motion, and the action of the telescopic rod is completed by utilizing the forward and reverse rotation of the motor. After the rotation speed of the engine is increased, the electric push rod is retracted, the linkage pin can extend into the pin hole under the action of the extension spring, and the first air inlet rocker arm and the second air inlet rocker arm are combined at the moment, so that the second air inlet rocker arm swings with the first air inlet rocker arm in the same swing amplitude, the lift of the air inlet valve is increased, and the air inflow is increased. When the rotation speed of the engine is reduced, the telescopic rod of the electric push rod is ejected out, so that the linkage pin is driven to move in a direction away from the pin hole and is separated from the pin hole, at the moment, the first air inlet rocker arm and the second air inlet rocker arm swing independently, the lift of an air inlet valve of the engine is reduced, and the air inflow is reduced.

In the variable valve structure of the motorcycle engine, the cylinder body is provided with the guide hole, the driving shaft is slidably arranged in the guide hole, and the driving piece is fixedly connected to the outer wall of the cylinder body. The electromagnet is fixedly connected to the outer wall of the cylinder body, so that the electromagnet can be conveniently installed and maintained. Through setting up guiding hole and drive shaft sliding fit, can promote the running accuracy of drive shaft to guarantee that the drive shaft can be stable, the accurate roof pressure universal driving shaft removes, hoisting device's stability and reliability.

In the variable valve structure of the motorcycle engine, the outer wall of the cylinder body is provided with the step hole communicated with the guide hole, the driving shaft is sleeved with the oil seal, and the oil seal is in sealing fit with the inner wall of the step hole. In order to ensure smooth movement of the driving shaft, lubricating substances such as grease can be smeared on the driving shaft, and at the moment, the grease can be isolated from the pollution of the external environment to the grease and the leakage of the grease can be avoided by arranging an oil seal, so that the driving shaft can be ensured to stably and accurately push against the linkage shaft to move all the time.

Compared with the prior art, the variable valve structure of the motorcycle engine has the following advantages:

1. according to the variable valve structure, the design requirement of the variable valve lift is met by adding the unique design of the second air inlet rocker arm and the clutch assembly, in the design, the first air inlet cam and the second air inlet cam are integrally formed on the cam shaft, so that the first air inlet cam and the second air inlet cam can be synchronously formed by machining the cam shaft, the complicated special-shaped surface is not required to be machined on the surface of the cam shaft to realize the switching of the air inlet valve lift, the situation that the cutting and machining processes of the cam shaft are more difficult due to the complicated shape can be avoided, and the machining cost of the cam shaft assembly is further reduced.

2. Because the first air inlet cam and the second air inlet cam are integrally formed on the cam shaft, the positions of the first air inlet cam and the second air inlet cam are not changed relative to the cam shaft, and even if the motorcycle is driven for a long time, the change amplitude of the lift of the air inlet valve can be kept consistent all the time when the clutch assembly is switched between the clutch state and the combined state, so that the variable valve structure has better reliability and working stability.

Drawings

Fig. 1 is a schematic structural view of a motorcycle engine.

Fig. 2 is a schematic view of the structure of the inside of the cylinder.

Fig. 3 is a schematic structural view of the present variable valve structure.

Fig. 4 is a schematic diagram of the structure of the camshaft, the first intake rocker arm, and the second intake rocker arm in the variable valve structure.

Fig. 5 is a partial cross-sectional view of the present variable valve structure when the first intake rocker arm and the second intake rocker arm swing independently of each other.

Fig. 6 is a partial cross-sectional view of the present variable valve structure when the intake rocker arm one and the intake rocker arm two are combined.

Fig. 7 is a side view of a camshaft.

Fig. 8 is an exploded view of the first intake rocker arm, the second intake rocker arm, the return spring and the interlock pin.

FIG. 9 is an exploded view of the first intake rocker arm, the second intake rocker arm, the return spring and the linkage pin.

Fig. 10 is a partial sectional view of the variable valve structure in the second embodiment when the first intake rocker arm and the second intake rocker arm swing independently of each other.

Fig. 11 is a partial sectional view of the variable valve structure in the second embodiment when the intake rocker arm one and the intake rocker arm two are combined.

In the figure, 1, a cylinder body; 1a, a guide hole; 1b, a step hole; 2. a rocker shaft; 3. a cam shaft; 31. an air inlet cam I; 32. an air inlet cam II; 33. an exhaust cam; 4. an air inlet rocker arm I; 41. a first linkage part; 411. a pin hole; 42. a rocker arm hole I; 43. the first matching plane is matched; 5. an intake valve; 6. an air inlet rocker arm II; 61. a second linkage part; 611. a mounting hole; 62. a rocker arm hole II; 63. a second matching plane; 7. a driving member; 71. a drive shaft; 8. a linkage pin; 81. a guide flange; 82. a bending part; 9. a return spring; 10. an electric push rod; 101. a telescopic rod; 11. a tension spring; 12. an oil seal; 13. a torsion spring; 14. an exhaust rocker arm; 15. and (5) an exhaust valve.

Detailed Description

The following are specific embodiments of the present invention and the technical solutions of the present invention will be further described with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

Example 1

As shown in fig. 1 to 3, in the variable valve structure of the motorcycle engine, the engine comprises a cylinder body 1, a rocker arm shaft 2 and a cam shaft 3 are arranged in the cylinder body 1, an exhaust rocker arm 14 is further arranged in the cylinder body 1, an intake rocker arm 4 is hinged on the rocker arm shaft 2, an intake cam 31, an intake cam 32 and an exhaust cam 33 are integrally formed on the cam shaft 3, one end of the exhaust rocker arm 14 is connected with an exhaust valve 15, and the other end of the exhaust rocker arm is abutted against the exhaust cam 33. As shown in fig. 4 and 7, the peak of the second intake cam 32 is opposite to the peak of the first intake cam 31 and higher than the peak of the first intake cam 31, one end of the first intake rocker arm 4 is connected with the intake valve 5, the other end of the first intake rocker arm abuts against the outer circumferential surface of the first intake cam 31, the rocker arm shaft 2 is further hinged with the second intake rocker arm 6 which can independently swing relative to the first intake rocker arm 4, the second intake rocker arm 6 is sleeved with a torsion spring 13, one end of the second intake rocker arm 6 can always abut against the outer circumferential surface of the second intake cam 32 by virtue of the action of the torsion spring 13, and the cylinder body 1 is further provided with a clutch component which can combine the first intake rocker arm 4 with the second intake rocker arm 6 and enable the first intake rocker arm 4 and the second intake rocker arm 6 to swing in the same amplitude.

As shown in fig. 5, 6, 8 and 9, the top of the first intake rocker arm 4 is provided with a first linkage part 41, the top of the second intake rocker arm 6 is provided with a second linkage part 61, the clutch assembly comprises a driving piece 7 and a linkage pin 8 which is arranged in parallel with the cam shaft 3, the linkage pin 8 axially slides and passes through the second linkage part 61, the first linkage part 41 is provided with a pin hole 411 which is matched with the outer diameter of the linkage pin 8, and the driving piece 7 can push the linkage pin 8 to move so that one end of the linkage pin 8 extends into the pin hole 411 to combine the first intake rocker arm 4 with the second intake rocker arm 6. The linkage pin 8 is arranged on the second linkage part 61 in a penetrating way along the axial sliding way, so that the linkage pin 8 can stably move axially. The second intake rocker arm 6 is also provided with a reset spring 9 which can drive the linkage pin 8 to deviate from the pin hole 411 so as to enable the first intake rocker arm 4 and the second intake rocker arm 6 to swing independently. The opposite end surfaces of the first linkage part 41 and the second linkage part 61 are planes, and the first linkage part 41 and the second linkage part 61 are close to or abutted against each other. The structure can ensure that the first linkage part 41 and the second linkage part 61 are close in position, so that the linkage pin 8 can stably and smoothly extend into or out of the pin hole 411, and the running stability and reliability of the variable valve structure are improved.

As shown in fig. 5 and 6, one end of the linkage pin 8, which can extend into the pin hole 411, is a front end, the other end is a rear end, the driving member 7 is an electromagnet fixedly connected to the cylinder 1, a driving shaft 71 is coaxially arranged between the driving member 7 and the linkage pin 8, one end face of the driving shaft 71 abuts against the rear end face of the linkage pin 8, and the driving member 7 can push the other end face of the driving shaft 71 and drive the driving shaft 71 to axially move. The second linkage part 61 is sleeve-shaped, a mounting hole 611 is formed in the second linkage part 61 and is axially arranged along the second linkage part, the linkage pin 8 is slidably arranged in the mounting hole 611, a guide convex edge 81 which is circumferentially arranged and is slidably matched with the inner wall of the mounting hole 611 is formed in the outer wall of the linkage pin 8, the reset spring 9 is sleeved on the linkage rod and is positioned in the mounting hole 611, and two ends of the reset spring 9 are respectively abutted against the guide convex edge 81 and the inner wall of the mounting hole 611.

As shown in fig. 5, 8 and 9, the first intake rocker arm 4 has a first rocker arm hole 42, the second intake rocker arm 6 has a second rocker arm hole 62, the rocker arm shaft 2 passes through the first rocker arm hole 42 and the first rocker arm hole 42, the first intake rocker arm 4 has a first mating plane 43 disposed around the first rocker arm hole 42 on the end face facing the second intake rocker arm 6, the second intake rocker arm 6 has a second mating plane 63 disposed around the second rocker arm hole 62 on the end face facing the first intake rocker arm 4, and the first mating plane 43 and the second mating plane 63 are abutted. The first air inlet rocker arm 4 and the second air inlet rocker arm 6 are sleeved on the rocker arm shaft 2 through the first rocker arm hole 42 and the second rocker arm hole 62 respectively, so that the first air inlet rocker arm 4 and the second air inlet rocker arm 6 are convenient to install and good in installation stability.

As shown in fig. 5 and 6, the cylinder 1 is provided with a guide hole 1a, a driving shaft 71 is slidably disposed in the guide hole 1a, and a driving member 7 is fixedly attached to the outer wall of the cylinder 1. The outer wall of the cylinder body 1 is provided with a step hole 1b communicated with the guide hole 1a, the driving shaft 71 is sleeved with an oil seal 12, and the oil seal 12 is in sealing fit with the inner wall of the step hole 1 b. In order to ensure smooth movement of the driving shaft 71, the driving shaft 71 is smeared with lubricating substances such as grease, and at this time, by arranging the oil seal 12, the pollution of the external environment to the grease can be isolated and the leakage of the grease can be avoided, so that the driving shaft 71 can stably and accurately push the linkage shaft to move all the time.

The working principle of the variable valve structure is described below with reference to the accompanying drawings:

when the motorcycle runs at a low speed and the engine is at a low speed, as shown in fig. 5, the linkage pin 8 does not extend into the pin hole 411, at this time, the clutch assembly is in a separated state, the first intake rocker arm 4 and the second intake rocker arm 6 swing independently, at this time, the lift of the intake valve 5 is controlled by the first intake rocker arm 4, and the second intake rocker arm 6 does not abut against the intake valve 5 so that the lift of the intake valve 5 is not affected by the action of the second intake rocker arm. And because the peach point of the first air inlet cam 31 is lower, the lift of the air inlet valve 5 is smaller in the process, and the air inflow is smaller.

After the rotation speed of the engine is increased, the driving piece 7 pushes the linkage pin 8, when the linkage pin 8 is aligned with the pin hole 411, the linkage pin 8 can extend into the pin hole 411, the linkage pin 8 is still subjected to the pushing force of the driving piece 7 and fixed in the pin hole 411, the force and the assembly are in a combined state, so that the first air intake rocker arm 4 and the second air intake rocker arm 6 are combined, as shown in fig. 6, the second air intake rocker arm 6 swings with the first air intake rocker arm 4 with the same swing amplitude, and at the moment, the second air intake rocker arm 6 abuts against the outer peripheral surface of the second air intake cam 32 and the peach point of the second air intake cam 32 is higher than the peach point of the first air intake cam 31, so that the swing amplitude of the first air intake rocker arm 4 is increased to be equal to the swing amplitude of the second air intake rocker arm 6, the lift of the engine 5 is increased, the air intake quantity is increased, the engine combustion is ensured to be more sufficient, emission is reduced, and the engine performance is optimized.

When the rotation speed of the engine is reduced, the driving piece 7 retreats to loosen the linkage pin 8, the linkage pin 8 is separated from the pin hole 411 under the action of the reset spring 9, so that the first air inlet rocker arm 4 and the second air inlet rocker arm 6 swing independently, as shown in fig. 5, at the moment, the lift of the air inlet valve 5 is reduced, and the air inflow is reduced.

Example two

The present embodiment is basically the same in structure and principle as the first embodiment, except that: as shown in fig. 10 and 11, the top of the first intake rocker arm 4 is provided with a first linkage part 41, the top of the second intake rocker arm 6 is provided with a second linkage part 61, the clutch assembly comprises a linkage pin 8 which is arranged in parallel with the cam shaft 3 and an electric push rod 10 which is fixedly connected to the cylinder body 1, the linkage pin 8 axially slides and passes through the second linkage part 61, the first linkage part 41 is provided with a pin hole 411 which is matched with the outer diameter of the linkage pin 8, the rear end of the linkage pin 8 extends out of the second linkage part 61, the rear end of the linkage pin 8 is provided with a bending part 82, the bending part 82 is connected with a tension spring 11 which can drive the linkage pin 8 to axially move and enable the front end of the linkage pin 8 to extend into the pin hole 411, the electric push rod 10 is provided with a telescopic rod 101 which is arranged in parallel with the linkage pin 8 and can axially extend and retract, and the end face of the telescopic rod 101 abuts against the bending part 82 and can push the linkage pin 8 to be separated from the pin hole 411.

The electric push rod 10 is a prior art, and can be purchased directly in the market, and the principle is that the rotary motion of a motor is changed into linear motion, and the action of the telescopic rod 101 is completed by forward and reverse rotation of the motor. As shown in fig. 11, after the engine speed increases, the electric push rod 10 retreats, and the linkage pin 8 can extend into the pin hole 411 under the action of the extension spring 11, and at this time, the first intake rocker arm 4 and the second intake rocker arm 6 are combined, so that the second intake rocker arm 6 swings with the first intake rocker arm 4 with the same swing amplitude, thereby increasing the lift of the intake valve 5 and increasing the intake air amount. As shown in fig. 10, when the engine speed decreases, the telescopic rod 101 of the electric push rod 10 is pushed out, thereby driving the linkage pin 8 to move away from the pin hole 411 and allowing the linkage pin 8 to come out of the pin hole 411, at this time, the first intake rocker arm 4 and the second intake rocker arm 6 swing independently, the lift of the engine intake valve 5 decreases, and the intake air amount decreases.

The specific embodiments described herein are offered by way of example only to illustrate the spirit of the invention. Those skilled in the art may make various modifications or additions to the described embodiments or substitutions thereof without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Although 1, cylinder is used more herein; 1a, a guide hole; 1b, a step hole; 2. a rocker shaft; 3. a cam shaft; 31. an air inlet cam I; 32. an air inlet cam II; 33. an exhaust cam; 4. an air inlet rocker arm I; 41. a first linkage part; 411. a pin hole; 42. a rocker arm hole I; 43. the first matching plane is matched; 5. an intake valve; 6. an air inlet rocker arm II; 61. a second linkage part; 611. a mounting hole; 62. a rocker arm hole II; 63. a second matching plane; 7. a driving member; 71. a drive shaft; 8. a linkage pin; 81. a guide flange; 82. a bending part; 9. a return spring; 10. an electric push rod; 101. a telescopic rod; 11. a tension spring; 12. an oil seal; 13. a torsion spring; 14. an exhaust rocker arm; 15. exhaust valve, etc., but does not exclude the possibility of using other terms. These terms are used merely for convenience in describing and explaining the nature of the invention; they are to be interpreted as any additional limitation that is not inconsistent with the spirit of the present invention.

Claims (10)

1. The utility model provides a variable valve structure of motorcycle engine, the engine includes cylinder body (1) and intake valve (5), be equipped with rocking arm axle (2) and camshaft (3) in cylinder body (1), variable valve structure is including connecting intake rocker arm (4) on rocking arm axle (2), characterized in that, have intake cam (31) and intake cam (32) on camshaft (3), the peach point portion of intake cam (32) is higher than the peach point portion of intake cam (31), intake rocker arm (4) one end and intake valve (5) hookup, the other end supports on the outer peripheral face of intake cam (31), still be connected with on rocking arm axle (2) and support on intake rocker arm (6) on intake cam (32) outer peripheral face and can be relative intake rocker arm (4) independent wobbling, still be equipped with on cylinder body (1) and can combine intake rocker arm (4) and intake rocker arm (6) and make intake rocker arm (4) and intake rocker arm (6) carry out clutch pack with the same range of swing.

2. The variable valve structure of the motorcycle engine according to claim 1, characterized in that the top of the first intake rocker arm (4) is provided with a first linkage part (41), the top of the second intake rocker arm (6) is provided with a second linkage part (61), the clutch assembly comprises a driving piece (7) and a linkage pin (8) which is arranged in parallel with the cam shaft (3), the linkage pin (8) is arranged on the second linkage part (61) in a sliding way along the axial direction of the linkage pin, the first linkage part (41) is provided with a pin hole (411) which is matched with the outer diameter of the linkage pin (8), and the driving piece (7) can push the linkage pin (8) to move so that one end of the linkage pin (8) stretches into the pin hole (411) to enable the first intake rocker arm (4) to be combined with the second intake rocker arm (6).

3. The variable valve structure of the motorcycle engine according to claim 2, characterized in that the second intake rocker arm (6) is further provided with a return spring (9) capable of driving the linkage pin (8) to come out of the pin hole (411) so as to enable the first intake rocker arm (4) and the second intake rocker arm (6) to swing independently.

4. The variable valve structure of a motorcycle engine according to claim 2, wherein the opposite end surfaces of the first linkage part (41) and the second linkage part (61) are both flat surfaces, and the first linkage part (41) and the second linkage part (61) are close to or abut against each other.

5. The variable valve structure of a motorcycle engine according to claim 2, 3 or 4, wherein one end of the linkage pin (8) capable of extending into the pin hole (411) is a front end, the other end is a rear end, the driving member (7) is an electromagnet fixedly connected to the cylinder body (1), a driving shaft (71) is coaxially arranged between the driving member (7) and the linkage pin (8), one end face of the driving shaft (71) abuts against the rear end face of the linkage pin (8), and the driving member (7) can push the other end face of the driving shaft (71) and drive the driving shaft (71) to axially move.

6. A variable valve structure of a motorcycle engine according to claim 3, characterized in that the second linkage part (61) is sleeve-shaped, a mounting hole (611) is formed in the second linkage part (61) along the axial direction of the second linkage part, the linkage pin (8) is arranged in the mounting hole (611), a guiding convex edge (81) which is arranged along the circumferential direction and is in sliding fit with the inner wall of the mounting hole (611) is formed on the outer wall of the linkage pin (8), the reset spring (9) is sleeved on the linkage pin (8), and two ends of the reset spring (9) respectively abut against the guiding convex edge (81) and the inner wall of the mounting hole (611).

7. A variable valve structure of a motorcycle engine according to claim 1 or 2 or 3 or 4, characterized in that the first intake rocker arm (4) has a first rocker arm hole (42), the second intake rocker arm (6) has a second rocker arm hole (62), the rocker arm shaft (2) passes through the first rocker arm hole (42) and the first rocker arm hole (42), respectively, the first intake rocker arm (4) has a first mating plane (43) disposed around the first rocker arm hole (42) on an end face facing the second intake rocker arm (6), the second intake rocker arm (6) has a second mating plane (63) disposed around the second rocker arm hole (62) on an end face facing the first intake rocker arm (4), and the first mating plane (43) and the second mating plane (63) are abutted.

8. The variable valve structure of a motorcycle engine according to claim 1, characterized in that the top of the first intake rocker arm (4) is provided with a first linkage part (41), the top of the second intake rocker arm (6) is provided with a second linkage part (61), the clutch assembly comprises a linkage pin (8) which is arranged in parallel with the cam shaft (3) and an electric push rod (10) which is fixedly connected to the cylinder body (1), the linkage pin (8) axially slides and passes through the second linkage part (61), the first linkage part (41) is provided with a pin hole (411) which is matched with the outer diameter of the linkage pin (8), the rear end of the linkage pin (8) extends out of the second linkage part (61), the rear end of the linkage pin (8) is provided with a bending part (82), the bending part (82) is connected with an extension spring (11) which can drive the linkage pin (8) to axially move and enable the front end of the linkage pin (8) to extend into the pin hole (411), the electric push rod (10) is provided with a pin hole (101) which is arranged in parallel with the linkage pin (8) and can axially push the extension pin (101) out of the bending part (82).

9. The variable valve structure of a motorcycle engine according to claim 5, characterized in that the cylinder (1) is provided with a guide hole (1 a), the driving shaft (71) is slidably disposed in the guide hole (1 a), and the driving member (7) is fixedly connected to the outer wall of the cylinder (1).

10. The variable valve structure of the motorcycle engine according to claim 9, characterized in that a stepped hole (1 b) communicated with the guide hole (1 a) is formed in the outer wall of the cylinder body (1), an oil seal (12) is sleeved on the driving shaft (71), and the oil seal (12) is in sealing fit with the inner wall of the stepped hole (1 b).