CN117988946A - Variable valve structure of engine - Google Patents

Abstract

The invention provides a variable valve structure of an engine, and belongs to the technical field of motorcycles. The variable valve structure solves the problem that the reliability of the variable valve structure in the prior art is insufficient. The variable valve structure of the engine comprises a first inlet rocker arm and a second inlet rocker arm which are arranged on a rocker arm shaft, wherein the cam shaft is provided with a first inlet cam and a second inlet cam, the first inlet rocker arm is in propping fit with the outer peripheral surface of the first inlet cam and can drive an inlet valve to open and close, a linkage pin parallel to the rocker arm shaft is arranged on the first inlet rocker arm in a penetrating mode, the linkage pin is arranged on one side, close to the inlet valve, of the rocker arm shaft and higher than the rocker arm shaft, the second inlet rocker arm is in propping fit with the outer peripheral surface of the second inlet cam, a pin hole which is parallel to the linkage pin and is matched with the outer diameter of the linkage pin is arranged on the second inlet rocker arm, a driving assembly is arranged on a cylinder cover, and the driving assembly is positioned on the outer side of the axis direction of the linkage pin and can push the linkage pin to enable the linkage pin to extend into the pin hole. The invention has the advantages of compact structure and high reliability.

Description

Variable valve structure of engine

Technical Field

The invention belongs to the technical field of motorcycles, and relates to a variable valve structure of an 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 of the intake valve is determined by the profile of the cam on the cam shaft, the conventional variable valve structure on the motorcycle generally adopts the intake cams with two different profiles or the intake cams with changeable profiles, and the intake cams with two different profiles are respectively contacted with the intake rocker arm by switching or the profiles of the intake cams are changed to be contacted with the intake rocker arm so as to change the action gesture of the intake rocker arm and further change the air inflow. In a variable valve lift apparatus (application number: 201620498502.6) of a tappet type engine for a motorcycle, disclosed in patent document, when the engine for a motorcycle runs at a high speed, a high-speed cam slider overcomes the acting force of a slider positioning spring, the high-speed cam slider is upwardly biased, a centrifugal block overcomes the acting force of a centrifugal block spring to rotate to a certain extent and drives a high-speed rotating shaft to rotate, and then the high-speed rotating shaft is utilized to push the high-speed cam slider to upwardly bias, and at the moment, the high-speed cam slider drives a rocker arm to rotate, so that an exhaust valve and an intake valve can lift. 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 an engine, which solves the technical problems that: how to improve the reliability of the variable valve structure and make the engine compact.

The aim of the invention can be achieved by the following technical scheme: the utility model provides a variable valve structure of engine, the engine includes cylinder head and cylinder cap, be equipped with rocking arm axle, camshaft and intake valve in the cylinder head, its characterized in that, variable valve structure is including setting up on the rocking arm axle intake rocking arm I and intake rocking arm II, have intake cam I and intake cam II on the camshaft, intake cam II's peach point portion is higher than intake cam I's peach point portion, intake rocking arm I supports the adaptation with intake cam I's outer peripheral face and can drive the intake valve and open and close, wear to be equipped with the linkage round pin that parallels with the rocking arm axle on the intake rocking arm I, the linkage round pin is located the rocking arm axle and is close to one side of intake valve and be higher than the rocking arm axle setting, intake rocking arm II supports the cooperation with intake cam II's outer peripheral face, be equipped with parallel to the linkage round pin and with linkage round pin external diameter assorted pinhole on the intake rocking arm II, be equipped with drive assembly on the cylinder cap, drive assembly is located the outside of linkage round pin axis direction and can push away the linkage round pin and make linkage round pin part stretch into in the pinhole.

When the motorcycle runs at a low speed and the engine is at a low rotation speed, the linkage pin is positioned at a position which does not extend into the pin hole, 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 does not abut against the air inlet valve, so that the action of the second air inlet rocker arm does not influence the lift of the air inlet valve. 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 driving component pushes the linkage pin, when the linkage pin is aligned with the pin hole, the linkage pin part stretches into the pin hole to enable the first air inlet rocker arm to be combined with the second air inlet rocker arm, at the moment, the second air inlet rocker arm swings with the same amplitude due to the fact that the pin hole is matched with the outer diameter of the linkage pin, and the second air inlet rocker arm is in abutting fit on 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 identical with that of the second air inlet rocker arm, the lift of the air inlet valve is increased, the air input is increased, the engine combustion is guaranteed to be more sufficient, emission is reduced, and the engine performance is optimized.

In this design, because intake cam one and intake cam two direct machine-shaping on the camshaft, this structure makes intake cam one and intake cam two processing convenience if can direct integrated into one piece, and then can guarantee intake cam one and intake cam two's machining precision, and then can promote the operating stability of this variable valve structure. In addition, the positions of the first air inlet cam and the second air inlet cam in the scheme cannot be changed relative to the cam shaft, even if the motorcycle is driven for a long time, the change amplitude of the valve lift can be kept consistent all the time, and the situation that the valve lift of the intake valve is abnormal due to the fact that the high-speed cam sliding block is not reset in place after the variable valve lift device (application number: 201620498502.6) of the tappet type engine of the motorcycle is used for a long time like the patent in the background art is avoided, so that the variable valve structure has good reliability and working stability.

In addition, in the scheme, the structure of the linkage pin matching pin hole occupies small space in the cylinder head, is favorable for compact design of the cylinder head, and reduces the size of the cylinder head. Meanwhile, the linkage pin is arranged at one side of the rocker arm shaft close to the air inlet valve and higher than the rocker arm shaft, namely, the linkage pin is arranged obliquely above the rocker arm shaft rather than just above the rocker arm shaft, and on the basis that the distance between the linkage pin and the rocker arm shaft is fixed, the height position of the linkage pin relative to the cylinder head can be reduced, so that the mounting height of a driving assembly positioned at the outer side of the axis direction of the linkage pin can be reduced, the height size of the engine can be further reduced, and the effect of compact structure is achieved.

In the variable valve structure of the engine, the cylinder head is provided with two opposite plate-shaped supporting parts, two ends of the rocker shaft are respectively and fixedly arranged on the two supporting parts in a penetrating mode, the inner wall of the cylinder cover is provided with an installation convex part for installing the driving assembly, and the supporting part close to the driving assembly is provided with a yielding step for avoiding the installation convex part. The two supporting parts respectively support the two ends of the rocker arm shaft, so that the installation stability of the rocker arm shaft can be improved. Through setting up the installation convex part, can be convenient for drive assembly's installation, and dodge the installation convex part through seting up the step of stepping down on the supporting part for the position of installation convex part can be reduced, drive assembly's installation height also can be reduced promptly, thereby reduces the high size of engine, reaches compact structure's effect.

In the variable valve structure of the engine, the step of stepping down is provided with a first mounting hole penetrating through the bottom surface of the cylinder head, and a fastener used for fixedly connecting the cylinder head with a cylinder body of the engine is arranged in the first mounting hole in a penetrating manner. By arranging the yielding step, the mounting surface of the fastener is lowered, and the mounting height of the driving assembly is lowered. The step of stepping down of supporting part is last to set up the fastener for the supporting part can supply the rocking arm axle to support, can also supply the fastener to pass and then utilize the fastener to realize linking firmly of cylinder head and cylinder body, has realized the multi-purpose of a thing promptly through the supporting part, thereby can simplify the cylinder head structure, reaches compact structure's effect.

In the variable valve structure of the engine, the step of stepping down is all offered on two supporting parts, and the step of stepping down on two supporting parts is all located one side that the supporting part is close to the intake valve, and mounting hole two has been offered respectively on the top surface that two supporting parts kept away from intake valve one side, mounting hole one's last port is less than mounting hole two's last port, all wear to be equipped with in mounting hole one and the mounting hole two and be used for making the fastener that cylinder end and the cylinder body of engine link firmly mutually. The two supporting parts are provided with the abdication steps, so that the two supporting parts form a symmetrical structure, and the processing is convenient. Through set up mounting hole one and mounting hole two respectively on the supporting part for have many fasteners to connect between cylinder head and the cylinder body, thereby make cylinder head and cylinder body connection more stable. The upper port of the first mounting hole is lower than the upper port of the second mounting hole, so that the height of the driving assembly above the first mounting hole is reduced, and the height dimension of the engine is reduced.

In the variable valve structure of the engine, the air inlet rocker arm is positioned at one side of the first back-facing driving component of the air inlet rocker arm, a cylindrical sleeving part sleeved on the rocker arm shaft is arranged on one side surface of the second back-facing air inlet rocker arm, and a torsion spring which enables the second air inlet rocker arm to be always abutted against and matched with the outer peripheral surface of the second air inlet cam is sleeved on the sleeving part. The design makes the rocker arm shaft be provided with the torsional spring, the air inlet rocker arm II and the air inlet rocker arm I in sequence along the direction close to the driving component, so that the distance between the linkage pin on the air inlet rocker arm I and the driving component is relatively short, the required length of the push rod is relatively short, the required installation space is relatively small, and the effect of compact structure can be achieved. The sleeving part is arranged on the second air inlet rocker arm and provides a mounting part for the torsion spring, so that the torsion spring is more stable to mount. The torsion spring can enable the second air inlet rocker arm to be stably and reliably abutted and matched on the outer peripheral surface of the second air inlet cam all the time, and the running stability of the device is improved.

In the variable valve structure of the engine, the top of the first air inlet rocker arm is provided with a cylindrical sleeve part, the second air inlet rocker arm is provided with an extending part which extends upwards relative to the sleeving part in an inclined manner, the pin hole is formed in the extending part, the linkage pin is arranged in the sleeve part in a sliding manner, and the sleeve part is also internally provided with a reset spring which can drive the linkage pin to move and separate from the pin hole. Because the linkage pin is positioned above the rocker shaft in an inclined way, the extension part extending upwards in an inclined way is arranged on the second air inlet rocker arm, so that the pin hole on the extension part can be opposite to the linkage pin, the purpose of reducing the height position of the linkage pin is achieved, and finally, the installation height of the driving assembly can be reduced. When the rotation speed of the engine is reduced, the driving assembly 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 engine, the first intake rocker arm and the second intake rocker arm are abutted, and a side surface of the first intake rocker arm, which is opposite to the second intake rocker arm, is abutted against a support part which is closer to the driving assembly. After the first air inlet rocker arm and the second air inlet rocker arm are attached, axial limit is formed, swing smoothness of the first air inlet rocker arm and the second air inlet rocker arm can be improved, deviation of installation positions caused by reduction of swing smoothness of the first air inlet rocker arm or the second air inlet rocker arm is avoided, and further, the condition that a linkage pin is difficult to extend into a pin hole is avoided, so that the variable valve structure is guaranteed to have higher running stability and reliability. The side surface of the first air inlet rocker arm, which is opposite to the second air inlet rocker arm, is abutted against the supporting part which is nearer to the driving assembly, so that the distance between the first air inlet cam and the linkage pin on the first air inlet cam and the driving assembly is nearer, the length required by the push rod is shorter, the installation space required by the push rod is smaller, and the effect of compact structure can be achieved.

In the variable valve structure of the engine, the mounting convex part is provided with the inserting hole and the guide hole which is positioned at the inner side of the inserting hole and is coaxial with the inserting hole, the driving assembly comprises a push rod which is arranged in the guide hole in a sliding penetrating mode and an electromagnet which is inserted and positioned in the inserting hole, and the electromagnet pushes the linkage pin to move through the push rod. Through setting up the guiding hole, realized the installation of push rod and formed the direction to its axial displacement, and then can guarantee that the electro-magnet can drive the stable removal of push rod. 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 engine, the electromagnet comprises a shell with an end part and a thimble capable of axially stretching relative to the shell, the end part of the electromagnet is inserted and fixed in the insertion hole, and the thimble of the electromagnet can push the push rod to axially move. The electromagnet is the prior art and can be directly purchased in the market, and generates a magnetic field when current passes through a coil of the electromagnet, and drives the thimble to stretch and retract through attraction or repulsion of magnetic force. The electromagnet is fixedly connected to the outer wall of the box cover through the bolts, and meanwhile the end head of the shell of the electromagnet is inserted and fixed in the insertion hole, so that the installation stability of the electromagnet can be further improved, the situation that the electromagnet is loose is avoided, the electromagnet can stably push the push rod to move, and the working reliability of the driving assembly is improved.

In the variable valve structure of the engine, the push rod is sleeved with the oil seal, the oil seal is in sealing fit with the inner wall of the plug hole, the guide hole and the plug hole are concentrically arranged, and the diameter of the plug hole is larger than that of the guide hole. In order to ensure smooth movement of the push rod, lubricating substances such as grease can be smeared on the push rod, and at the moment, the oil seal is arranged in the inserting hole, so that the pollution of the external environment to the grease can be isolated, the leakage of the grease is avoided, the push rod can be ensured to stably and accurately axially move all the time, and the working reliability of the driving assembly is improved. The diameter of the inserting hole is larger, so that the electromagnet can be conveniently inserted and fixed, and the electromagnet is installed.

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

1. in the variable valve structure, the first air inlet cam and the second air inlet cam are directly formed on the cam shaft in a machining mode, and the positions of the first air inlet cam and the second air inlet cam are not changed relative to the cam shaft in the running process of the motorcycle, so that the variable valve structure has good reliability and working stability.

2. Offer the step of stepping down on the supporting part and dodge the installation convex part for the position of installation convex part can be reduced, drive assembly's installation height also can be reduced promptly, thereby reduce the high size of engine, reach compact structure's effect.

Drawings

Fig. 1 is a perspective view of the engine cylinder head and head.

Fig. 2 is a perspective view of the structure of the present variable valve.

Fig. 3 is a schematic diagram of the structures of the first intake rocker arm, the second intake rocker arm, the rocker arm shaft and the camshaft in the present variable valve structure.

Fig. 4 is a partial schematic view of the present variable valve structure.

Fig. 5 is a front view of a camshaft in the present variable valve structure.

Fig. 6 is a sectional view of the present variable valve structure.

Fig. 7 is a schematic view of the cylinder head in the present variable valve structure.

Fig. 8 is a schematic structural view of a cylinder head in the present variable valve structure.

Fig. 9 is a schematic diagram of the structure of the intake rocker arm two in the present variable valve structure.

Fig. 10 is an enlarged view of a portion a of the present variable valve structure diagram 6.

FIG. 11 is a partial cross-sectional view of the first and second intake rocker arms with the interlocking pin portion extending into the pin bore.

In the figure, 1, a cylinder cover; 1a, mounting convex parts; 1a1, a plug hole; 1a2, a guide hole; 2. a cylinder head; 21. a support part; 211. a step of giving way; 3. a rocker shaft; 4. a cam shaft; 41. an air inlet cam I; 42. an air inlet cam II; 43. an exhaust cam; 44. peach tips; 5. an intake valve; 6. an exhaust rocker arm; 7. an air inlet rocker arm I; 71. a sleeve portion; 8. an air inlet rocker arm II; 81. an extension; 82. a socket joint part; 9. a drive assembly; 91. a push rod; 92. an electromagnet; 921. an end portion; 922. a thimble; 10. a pin hole; 11. a linkage pin; 12. a first mounting hole; 13. a fastener; 14. a second mounting hole; 15. a torsion spring; 16. a return spring; 17. and (3) oil sealing.

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 and 2, the engine comprises a cylinder body, a cylinder head 2 and a cylinder cover 1 which are sequentially arranged from bottom to top, wherein the cylinder body is in the prior art, and the cylinder body is not shown in the figure. The cylinder head 2 is internally provided with a rocker arm shaft 3, a cam shaft 4, an intake valve 5 and an exhaust rocker arm 6, and the variable valve structure of the engine comprises an intake rocker arm 7 and an intake rocker arm 8 which are arranged on the rocker arm shaft 3.

As shown in fig. 2 to 5, the camshaft 4 is provided with a first intake cam 41, a second intake cam 42 and an exhaust cam 43, the peak 44 of the second intake cam 42 is higher than the peak 44 of the first intake cam 41, the first intake rocker 7 is in abutting fit with the outer peripheral surface of the first intake cam 41 and can drive the intake valve 5 to open and close, the first intake rocker 7 is provided with a linkage pin 11 parallel to the rocker arm shaft 3 in a penetrating way, the linkage pin 11 is positioned on one side of the rocker arm shaft 3 close to the intake valve 5 and higher than the rocker arm shaft 3, the second intake rocker 8 is in abutting fit with the outer peripheral surface of the second intake cam 42, the second intake rocker 8 is provided with a pin hole 10 parallel to the linkage pin 11 and matched with the outer diameter of the linkage pin 11, the cylinder cover 1 is provided with a driving component 9, and the driving component 9 is positioned on the outer side of the axis direction of the linkage pin 11 and can push the linkage pin 11 to enable the linkage pin 11 to extend into the pin hole 10 partially.

As shown in fig. 2 to 5, the second intake rocker arm 8 is located on the side of the first intake rocker arm 7 facing away from the driving component 9, and as shown in fig. 8, the side of the second intake rocker arm 8 facing away from the first intake rocker arm 7 is provided with a cylindrical sleeve-shaped portion 82 sleeved on the rocker arm shaft 3, and the sleeve-shaped portion 82 is sleeved with a torsion spring 15 which enables the second intake rocker arm 8 to be always in abutting fit on the outer peripheral surface of the second intake cam 42. The top of the first intake rocker arm 7 is provided with a cylindrical sleeve abutting cylinder part 71, the second intake rocker arm 8 is provided with an extending part 81 which extends upwards obliquely relative to a sleeving part 82, the pin hole 10 is arranged on the extending part 81, the linkage pin 11 is arranged in the sleeve part 71 in a sliding penetrating way, and the sleeve part 71 is internally provided with a reset spring 16 which can drive the linkage pin 11 to move and separate from the pin hole 10.

As shown in fig. 6, 7 and 8, the cylinder head 2 has two opposite plate-shaped support portions 21, and both ends of the rocker shaft 3 are fixedly inserted into the two support portions 21, respectively, and the two support portions 21 support both ends of the rocker shaft 3, respectively, so that the mounting stability of the rocker shaft 3 can be improved. As shown in fig. 8, the inner wall of the cylinder head 1 has an installation protrusion 1a for installing the driving unit 9, and by providing the installation protrusion 1a, the driving unit 9 can be installed conveniently, and the support portion 21 near the driving unit 9 is provided with a step 211 for avoiding the installation protrusion 1 a. The step 211 is provided with a first mounting hole 12 penetrating through the bottom surface of the cylinder head 2, and a fastener 13 for fixedly connecting the cylinder head 2 with the cylinder body of the engine is penetrated in the first mounting hole 12.

Further, as shown in fig. 7, the two support portions 21 are provided with the step 211 of stepping down, the step 211 of stepping down on the two support portions 21 is located at one side of the support portion 21 close to the intake valve 5, the top surfaces of one side of the two support portions 21 away from the intake valve 5 are respectively provided with the second mounting hole 14, the first mounting hole 12 and the second mounting hole 14 are internally provided with the fastening piece 13 for fixedly connecting the cylinder head 2 with the cylinder body of the engine, and the upper port of the first mounting hole 12 is lower than the upper port of the second mounting hole 14. By arranging the first mounting hole 12 and the second mounting hole 14 on the supporting part 21 respectively, a plurality of fasteners 13 are arranged between the cylinder head 2 and the cylinder body for connection, so that the connection between the cylinder head 2 and the cylinder body is more stable.

As shown in fig. 10 and 11, the first intake rocker arm 7 and the second intake rocker arm 8 are abutted, and the side surface of the first intake rocker arm 7 facing away from the second intake rocker arm 8 is abutted against the support portion 21 closer to the drive unit 9. After the first air inlet rocker arm 7 and the second air inlet rocker arm 8 are attached, axial limit is formed, swing smoothness of the first air inlet rocker arm 7 and the second air inlet rocker arm 8 can be improved, and therefore the variable valve structure is guaranteed to have higher operation stability and reliability.

As shown in fig. 10 and 11, the mounting protrusion 1a is provided with a plugging hole 1a1 and a guiding hole 1a2 which is positioned at the inner side of the plugging hole 1a1 and is coaxial with the plugging hole 1a1, and the driving assembly 9 comprises a push rod 91 which is slidably arranged in the guiding hole 1a2 and an electromagnet 92 which is inserted and positioned in the plugging hole 1a1, and the electromagnet 92 pushes the linkage pin 11 to move through the push rod 91. The electromagnet 92 includes a housing having an end 921 and a thimble 922 capable of extending and retracting axially with respect to the housing, the end 921 of the electromagnet 92 is fixed in the insertion hole 1a1, and the thimble 922 of the electromagnet 92 can push the push rod 91 to move axially. The push rod 91 is sleeved with an oil seal 17, the oil seal 17 is in sealing fit with the inner wall of the plug hole 1a1, the guide hole 1a2 is arranged concentrically with the plug hole 1a1, and the diameter of the plug hole 1a1 is larger than that of the guide hole 1a 2. Electromagnet 92 is a prior art, commercially available, which generates a magnetic field when current is passed through the coil of electromagnet 92 and causes retraction of spike 922 by attraction or repulsion of the magnetic force.

The working principle of the variable valve structure is described below:

As shown in fig. 10, when the motorcycle is running at a low speed and the engine is at a low speed, the interlocking pin 11 is in a position not extending into the pin hole 10, so that both the first intake rocker arm 7 and the second intake rocker arm 8 swing independently, at which time the lift of the intake valve 5 is controlled by the first intake rocker arm 7, and the second intake rocker arm 8 does not abut against the intake valve 5 so that its action does not affect the lift of the intake valve 5. And the lift of the intake valve 5 in the process is smaller and the intake air amount is smaller because the peaked portion 44 of the intake cam one 41 is lower.

As shown in fig. 11, when the motorcycle runs at a high speed and the engine is at a high speed, the driving assembly 9 pushes the linkage pin 11, when the linkage pin 11 is aligned with the pin hole 10, the linkage pin 11 partially stretches into the pin hole 10 to combine the first air intake rocker arm 7 with the second air intake rocker arm 8, at this time, the second air intake rocker arm 8 swings with the same amplitude as the first air intake rocker arm 7 due to the matching of the pin hole 10 and the outer diameter of the linkage pin 11, and the second air intake rocker arm 8 abuts against the outer peripheral surface of the second air intake cam 42 and the peak 44 of the second air intake cam 42 is higher than the peak 44 of the first air intake cam 41, so that the swing amplitude of the first air intake rocker arm 7 is increased to be the same as the swing amplitude of the second air intake rocker arm 8, the lift of the intake valve 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 engine speed decreases, the driving assembly 9 retreats to release the linkage pin 11, the linkage pin 11 is separated from the pin hole 10 under the action of the return spring 16, and the state shown in fig. 10 is returned, at this time, the first intake rocker arm 7 and the second intake rocker arm 8 swing independently, the lift of the intake valve 5 decreases, and the intake air amount decreases.

Example two

The present embodiment is basically the same in structure and principle as the first embodiment, except that: the driving component 9 is a push rod motor, and the working principle of the push rod motor is that the rotary motion of the motor is converted into the linear reciprocating motion of the push rod, so that the push rod of the push rod motor is utilized to push the linkage pin 11 to move. When the push rod of the push rod motor stretches out, the linkage pin 11 can stretch into the pin hole 10, and when the push rod of the push rod motor retreats, the linkage pin 11 is separated from the pin hole 10 under the action of the reset spring 16.

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 head are used more herein; 1a, mounting convex parts; 1a1, a plug hole; 1a2, a guide hole; 2. a cylinder head; 21. a support part; 211. a step of giving way; 3. a rocker shaft; 4. a cam shaft; 41. an air inlet cam I; 42. an air inlet cam II; 43. an exhaust cam; 44. peach tips; 5. an intake valve; 6. an exhaust rocker arm; 7. an air inlet rocker arm I; 71. a sleeve portion; 8. an air inlet rocker arm II; 81. an extension; 82. a socket joint part; 9. a drive assembly; 91. a push rod; 92. an electromagnet; 921. an end portion; 922. a thimble; 10. a pin hole; 11. a linkage pin; 12. a first mounting hole; 13. a fastener; 14. a second mounting hole; 15. a torsion spring; 16. a return spring; 17. oil seals, and the like, but do 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 variable valve structure of the engine comprises a cylinder cover (1) and a cylinder head (2), wherein a rocker arm shaft (3), a cam shaft (4) and an intake valve (5) are arranged in the cylinder head (2), and the variable valve structure is characterized by comprising a first intake rocker arm (7) and a second intake rocker arm (8) which are arranged on the rocker arm shaft (3), the cam shaft (4) is provided with a first intake cam (41) and a second intake cam (42), a peak part (44) of the second intake cam (42) is higher than a peak part (44) of the first intake cam (41), the first intake rocker arm (7) is in abutting fit with the peripheral surface of the first intake cam (41) and can drive the intake valve (5) to open and close, a linkage pin (11) parallel to the rocker arm shaft (3) is arranged on the first intake rocker arm shaft (7), and the linkage pin (11) is arranged on one side, close to the intake valve (5), of the rocker arm shaft (3) and higher than the rocker arm shaft (3); the cylinder cover is characterized in that the second air inlet rocker arm (8) is in abutting fit with the outer peripheral surface of the second air inlet cam (42), a pin hole (10) which is parallel to the linkage pin (11) and matched with the outer diameter of the linkage pin (11) is formed in the second air inlet rocker arm (8), a driving assembly (9) is arranged on the cylinder cover (1), and the driving assembly (9) is located on the outer side of the axis direction of the linkage pin (11) and can push the linkage pin (11) to enable the linkage pin (11) to extend into the pin hole (10).

2. The variable valve structure of an engine according to claim 1, wherein the cylinder head (2) has two opposite plate-shaped supporting portions (21), two ends of the rocker shaft (3) are respectively and fixedly arranged on the two supporting portions (21) in a penetrating manner, an installation convex portion (1 a) for installing the driving assembly (9) is arranged on the inner wall of the cylinder cover (1), and a step (211) for avoiding the installation convex portion (1 a) is arranged on the supporting portion (21) close to the driving assembly (9).

3. The variable valve structure of the engine according to claim 2, wherein the step (211) is provided with a first mounting hole (12) penetrating through the bottom surface of the cylinder head (2), and a fastener (13) for fixedly connecting the cylinder head (2) with the cylinder body of the engine is arranged in the first mounting hole (12).

4. The variable valve structure of an engine according to claim 3, wherein the two support portions (21) are provided with a step (211) of stepping down, the step (211) of stepping down on the two support portions (21) is located at one side of the support portions (21) close to the intake valve (5), the top surfaces of one side of the two support portions (21) far away from the intake valve (5) are provided with two mounting holes (14) respectively, the upper port of the first mounting hole (12) is lower than the upper port of the second mounting hole (14), and fasteners (13) for fixedly connecting the cylinder head (2) with a cylinder body of the engine are respectively arranged in the first mounting hole (12) and the second mounting hole (14).

5. A variable valve structure of an engine according to claim 2, 3 or 4, characterized in that the intake rocker arm two (8) is located at one side of the intake rocker arm two (7) facing away from the driving assembly (9), and the side of the intake rocker arm two (8) facing away from the intake rocker arm one (7) is provided with a cylindrical sleeve joint part (82) sleeved on the rocker arm shaft (3), and the sleeve joint part (82) is sleeved with a torsion spring (15) which enables the intake rocker arm two (8) to be always abutted and matched on the outer peripheral surface of the intake cam two (42).

6. The variable valve structure of an engine according to claim 5, wherein the top of the first intake rocker arm (7) is provided with a cylindrical sleeve portion (71), the second intake rocker arm (8) is provided with an extending portion (81) extending obliquely upwards relative to the sleeve portion (82), the pin hole (10) is formed in the extending portion (81), the linkage pin (11) is slidably inserted into the sleeve portion (71), and a return spring (16) capable of driving the linkage pin (11) to move and separate from the pin hole (10) is further arranged in the sleeve portion (71).

7. The variable valve structure of an engine according to claim 5, characterized in that the first intake rocker arm (7) and the second intake rocker arm (8) are abutted, and a side of the first intake rocker arm (7) facing away from the second intake rocker arm (8) is abutted against a support portion (21) closer to the driving unit (9).

8. The variable valve structure of an engine according to claim 2, 3 or 4, wherein the mounting protrusion (1 a) is provided with a plug hole (1 a 1) and a guide hole (1 a 2) which is positioned at the inner side of the plug hole (1 a 1) and is coaxial with the plug hole (1 a 1), the driving assembly (9) comprises a push rod (91) which is slidably penetrated in the guide hole (1 a 2) and an electromagnet (92) which is inserted in the plug hole (1 a 1), and the electromagnet (92) pushes the linkage pin (11) to move through the push rod (91).

9. The variable valve structure of an engine according to claim 8, wherein the electromagnet (92) includes a housing having an end portion (921) and a thimble (922) axially retractable with respect to the housing, the end portion (921) of the electromagnet (92) is inserted and fixed in the insertion hole (1 a 1), and the thimble (922) of the electromagnet (92) is capable of pushing the push rod (91) to move axially.

10. The variable valve structure of an engine according to claim 8, wherein the push rod (91) is sleeved with an oil seal (17), the oil seal (17) is in sealing fit with the inner wall of the insertion hole (1 a 1), the guide hole (1 a 2) is concentrically arranged with the insertion hole (1 a 1), and the diameter of the insertion hole (1 a 1) is larger than that of the guide hole (1 a 2).