Valve stroke loss mechanism of engine

Abstract

According to the valve stroke loss mechanism for the engine, the valve stroke loss mechanism for the engine comprises a transmission cam, the transmission cam is integrated in a valve driving system of the engine, and rotation of the transmission cam generates a gap in the valve driving system of the engine, so that the valve stroke of the engine is lost.

Description

Technical Field

[0001] The utility model relates to the field of machinery, in particular to the field of engine valve drive, and particularly to a valve stroke loss mechanism of an engine. Background Art

[0002] In the prior art, the conventional valve drive of a vehicle engine is well-known and has been applied for more than one hundred years. The conventional valve drive uses a conventional valve actuator (including a rocker arm) to control the movement of the engine valve for the conventional ignition operation of the engine. However, due to the additional requirements for engine fuel efficiency, exhaust emissions, and engine braking, more and more engines adopt variable valve drive, including engine cylinder deactivation that completely eliminates valve movement, and engine braking has also been widely adopted for commercial vehicle engines.

[0003] Chinese Patent CN104411925B (2018) discloses a system, method, and device for controlling variable valve operation in an automotive engine. Two cams have different lift profiles, and two rocker arms are respectively straddled on the two cams. The two rocker arms are locked by a latch to transmit different cam lift profiles to the engine valve. This invention has a top cam acting on the roller in the center of the rocker arm, and its application is limited to passenger cars.

[0004] Chinese Patent CN102373979B (2015) discloses a rocker arm mechanism for engine cylinder deactivation, including an outer rocker arm and an inner rocker arm. The inner and outer rocker arms are connected by a latch to transmit the movement of the cam to the valve. When the connection of the latch is disconnected, the movement of the cam is lost, the valve lift is zero, and the engine cylinder deactivates. Similarly, this invention has a top cam acting on the roller in the center of the rocker arm, and its application is limited to passenger cars.

[0005] U.S. Patent US 5,537,976 (1996) discloses another device and method for two-stroke engine braking, which adopts means such as cam drive, hydraulic connection, high-speed solenoid valve, and electronic control to achieve different valve movements and realize engine ignition or engine braking. Since the solenoid valve needs to be opened at least once in each cycle, there are particularly high requirements for the reliability and durability of the solenoid valve. Coupled with other problems of hydraulic drive, such as the control of valve seating speed, cold start of the engine, etc., this invention has not been actually applied.

[0006] U.S. Patent No. 6,293,248 (2001) discloses yet another device and method for braking a two-stroke engine. To implement two-stroke engine braking on a four-stroke engine, in addition to four cams, four rocker arms must also be used: two exhaust rocker arms (one of which is for braking) and two intake rocker arms (one of which is for braking). The structure and control are both complex, and hydraulic drive is also used to open the engine valves. Summary of the Utility Model

[0007] The purpose of the present utility model is to provide a valve stroke loss mechanism for an engine, aiming to solve the technical problems in the prior art that the engine valve drive structure and control are complex, the reliability and durability of hydraulic drive for opening valves are poor, and the application is limited.

[0008] To solve the above technical problems, the present utility model provides the following technical solutions:

[0009] In the first aspect of the present utility model, a valve stroke loss mechanism for an engine is provided, including a transmission mechanism integrated in the valve drive system of the engine. The transmission mechanism includes a transmission cam, and the rotation of the transmission cam generates a gap in the valve drive system of the engine, resulting in a loss of the valve stroke of the engine.

[0010] Further, in the valve stroke loss mechanism for an engine provided in the first aspect of the present utility model, the profile of the transmission cam has different curvatures, including a section with equal curvature at the highest position of the profile.

[0011] Further, in the valve stroke loss mechanism for an engine provided in the first aspect of the present utility model, the loss of the valve stroke of the engine includes partial loss and complete loss.

[0012] Further, in the valve stroke loss mechanism for an engine provided in the first aspect of the present utility model, the transmission mechanism further includes a drive mechanism for rotating the transmission cam. The drive mechanism includes a spring-piston mechanism, and the spring-piston mechanism includes a drive piston and a return spring.

[0013] Further, in the valve stroke loss mechanism for an engine provided in the first aspect of the present utility model, the transmission cam is rotatably arranged on the rocker arm of the engine. When the transmission cam rotates to different positions, the gap in the valve drive system of the engine changes, the movement transmitted from the engine cam to the valve is changed, and the valve lift has a predetermined degree of loss.

[0014] Further, in the valve stroke loss mechanism for an engine provided in the first aspect of the present utility model, a valve clearance adjustment mechanism is further included.

[0015] Further, the valve stroke loss mechanism of the engine provided by the first aspect of the present utility model, wherein the valve drive system of the engine includes a first rocker arm that rotates around a first axis and a second rocker arm that rotates relative to the first rocker arm. One end of the first rocker arm is close to the valve of the engine, and the second rocker arm is rotatably connected to a second axis. It is characterized in that: the transmission mechanism is arranged on the first rocker arm and is connected to one end of the second rocker arm, and the other end of the second rocker arm is connected to the cam of the engine. When the transmission cam of the transmission mechanism rotates to different positions, the relative position between the first rocker arm and the second rocker arm changes, and the motion transmitted from the cam of the engine to the valve is changed, resulting in a predetermined degree of loss of valve lift.

[0016] Further, the valve stroke loss mechanism of the engine provided by the first aspect of the present utility model, wherein the transmission mechanism further includes a transmission piston, and the transmission piston is located between the transmission cam and the second rocker arm. When the transmission cam rotates to different positions, the force-bearing position where the end face of the second rocker arm interacts with the transmission piston changes, and the movement of the end face of the second rocker arm in its normal direction is less than the movement in its tangential direction.

[0017] Further, the valve stroke loss mechanism of the engine provided by the first aspect of the present utility model, which further includes an anti-flying-off spring, and the anti-flying-off spring pushes the second rocker arm towards the cam of the engine.

[0018] Further, the valve stroke loss mechanism of the engine provided by the first aspect of the present utility model, which further includes a stop mechanism, and the stop mechanism is used to limit the relative rotation of the first rocker arm and the second rocker arm on the axis.

[0019] In the second aspect of the present utility model, a valve stroke loss mechanism of an engine is provided, which includes a transmission mechanism integrated in the engine valve drive system. The transmission mechanism includes a transmission cam, and the rotation of the transmission cam generates a clearance in the engine valve drive system, resulting in partial loss and complete loss of the engine valve stroke.

[0020] Optionally, the transmission cam includes a base circle portion and a convex portion. The rotation of the transmission cam generates a clearance in the engine valve drive system by the base circle portion and reduces or eliminates the clearance in the engine valve drive system by the convex portion.

[0021] Optionally, the profile of the transmission cam has different curvatures, including equal curvature, and the equal curvature is set in a section of the highest position of the profile.

[0022] Optionally, the transmission mechanism further includes a drive mechanism for rotating the transmission cam, and the drive mechanism includes a spring-piston mechanism, and the spring-piston mechanism includes a drive piston and a return spring.

[0023] Optionally, the return spring pushes the drive piston to move, thereby rotating the transmission cam. The clearance generated by the transmission cam in the engine valve drive system causes a loss of the engine valve stroke; the engine oil overcomes the force of the return spring to push the drive piston to move, thereby rotating the transmission cam, and the clearance generated by the transmission cam in the engine valve drive system is reduced or eliminated to increase or fully restore the movement of the engine valve.

[0024] Optionally, the transmission mechanism further includes a connecting pin, one end of the connecting pin is connected to the transmission cam, and the other end of the connecting pin is connected to the drive piston.

[0025] Optionally, the engine valve drive system includes a rocker arm, and the transmission mechanism is arranged on the rocker arm of the engine. When the transmission cam rotates to different positions, the clearance in the engine valve drive system changes, and the movement transmitted by the engine cam to the engine valve is changed, and the lift of the engine valve is lost to a predetermined extent.

[0026] Optionally, the engine valve drive system further includes a valve clearance adjusting mechanism.

[0027] Optionally, the transmission mechanism is arranged at one end of the rocker arm close to the engine valve. When the transmission cam rotates to different positions, the clearance in the engine valve drive system changes, where

[0028] When the base circle portion of the transmission cam rotates close to the engine valve, a clearance is generated between the base circle portion and the engine valve, and the engine valve stroke is partially lost and completely lost;

[0029] When the boss portion of the transmission cam rotates close to the engine valve, the clearance is reduced or eliminated to increase or fully restore the movement of the engine valve.

[0030] Optionally, the transmission mechanism is arranged at one end of the rocker arm close to the engine cam. When the transmission cam rotates to different positions, the clearance in the engine valve drive system changes, where

[0031] When the base circle portion of the transmission cam rotates close to the engine cam, a clearance is generated between the base circle portion and the engine cam, and the engine valve stroke is partially lost and completely lost;

[0032] When the boss portion of the transmission cam rotates to approach the engine cam, the clearance is reduced or eliminated to increase or fully restore the movement of the engine valve.

[0033] Optionally, the valve drive system of the engine includes a first rocker arm that rotates around a first axis and a second rocker arm that rotates relative to the first rocker arm. One end of the first rocker arm is close to the engine valve. The second rocker arm is rotatably connected to a second axis. The characteristics are as follows: The transmission mechanism is arranged on the first rocker arm and is in contact connection with one end of the second rocker arm. The other end of the second rocker arm is in contact connection with the engine cam. When the transmission cam of the transmission mechanism rotates to different positions, the relative position between the first rocker arm and the second rocker arm changes, and the movement transmitted by the engine cam to the engine valve is changed, and the lift of the engine valve has a predetermined degree of loss.

[0034] Optionally, the valve drive system of the engine further includes an anti-fly-off spring that pushes the second rocker arm towards the engine cam.

[0035] Optionally, the transmission mechanism further includes a transmission piston. The transmission piston is located between the transmission cam and the second rocker arm. When the transmission cam rotates to different positions, the force-bearing position where the end face of the second rocker arm interacts with the transmission piston changes, and the movement of the end face of the second rocker arm in its normal direction is less than the movement in its tangential direction.

[0036] Optionally, the valve drive system of the engine further includes a stop mechanism that is used to limit the relative rotation of the first rocker arm and the second rocker arm on the shaft.

[0037] In the third aspect of the present utility model, an engine is provided, which includes the above-mentioned rocker arm mechanism provided in the first aspect and the second aspect of the present utility model.

[0038] In the fourth aspect of the present utility model, a vehicle is provided, which includes the above-mentioned engine.

[0039] Advantages of the present utility model

[0040] Compared with the prior art, the effect of the present utility model is positive and obvious. The mechanism of the present utility model includes a transmission cam. Through the movement of the transmission cam, the movement of the engine valve is generated or lost, realizing the conversion between engine ignition and engine cylinder shutdown or braking, etc. It has the advantages of simple and reliable structure, easy manufacturing and assembly, and wide application. In particular, the structure is simple and reliable, and the amount of expansion and contraction and the movement speed of the transmission piston generated can be controlled (achieved by designing the cam profile according to needs), and it can be applied to variable valve drives of engines with large lift, including engine cylinder shutdown with the entire valve lift cancelled and engine braking with a large stroke, as well as applications in scenarios with limited installation space.

[0041] In addition, the rocker arm mechanism of the present utility model can be a single rocker arm or composed of a first rocker arm and a second rocker arm. The first rocker arm and the second rocker arm are interconnected (locked) or separated (released) through the conversion of the working surface with the transmission piston, generating or losing the valve movement of the engine, realizing the conversion between engine ignition and engine cylinder deactivation or braking, etc. By designing the shape of the working surface, the effect that a relatively small stroke of the transmission piston can generate a relatively large idle stroke (stroke loss) can be achieved. Therefore, it has the advantages of simple and reliable structure, easy manufacturing and assembly, and wide application, etc. Description of the Drawings

[0042] Figure 1 is a schematic diagram of the separation between the transmission cam and the engine valve in the embodiment of the valve stroke loss mechanism of the present utility model;

[0043] Figure 2 is a schematic diagram of the contact between the transmission cam and the engine valve in the embodiment of the valve stroke loss mechanism of the present utility model;

[0044] Figure 3 is a schematic diagram of the separation between the transmission cam and the engine cam in the embodiment of the valve stroke loss mechanism of the present utility model;

[0045] Figure 4 is a schematic diagram of the contact between the transmission cam and the engine cam in the embodiment of the valve stroke loss mechanism of the present utility model;

[0046] Figure 5 is a schematic diagram of the contour curve of the transmission cam of the present utility model;

[0047] Figure 6 is a schematic diagram of the state without stroke loss in the embodiment of the valve stroke loss mechanism of the present utility model;

[0048] Figure 7 is a schematic diagram of the state with stroke loss in the embodiment of the valve stroke loss mechanism of the present utility model;

[0049] Figure 8 is a schematic diagram of the adjustable valve clearance in the embodiment of the valve stroke loss mechanism of the present utility model. Detailed Embodiments

[0050] The following specific embodiments illustrate the implementation manners of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification.

[0051] It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the implementation conditions of the present utility model. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the efficacy that the present utility model can generate and the purpose that can be achieved, should still fall within the scope that the technical content disclosed by the present utility model can cover. At the same time, the terms "first", "second", and "third" in this specification are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0052] The following will describe the implementation scheme of the present utility model in detail in conjunction with embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present utility model and should not be regarded as limiting the scope of the present utility model. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0053] Embodiment 1

[0054] In one example, an engine valve stroke loss mechanism includes a transmission mechanism, and the transmission mechanism includes a transmission cam. The transmission cam is integrated in the engine valve drive system. The rotation of the transmission cam generates a gap in the engine valve drive system, resulting in the loss of the engine valve stroke.

[0055] In one example, the profile of the intermediate cam has different curvatures, including a flat top with a constant curvature at the highest position of the profile lift.

[0056] In one example, referring to Figure 1 , the transmission cam 102 includes a base circle portion 1021 and a boss portion 1022. The rotation of the transmission cam 102 generates a gap in the engine valve drive system by the base circle portion 1021, and causes the gap in the engine valve drive system to decrease or disappear by the boss portion 1022.

[0057] In one example, the loss of the engine valve stroke includes partial loss and total loss.

[0058] In one example, the engine valve drive system includes a rocker arm. The transmission mechanism is arranged on the rocker arm of the engine. When the transmission cam rotates to different positions, the gap in the engine valve drive system changes, the motion transmitted by the engine cam to the engine valve is changed, and the lift of the engine valve has a predetermined degree of loss.

[0059] As Figure 1 、 2As shown in the figure, the engine valve stroke loss mechanism includes the cam 230 of the engine, the rocker arm 10, and the valve 301 (the old model engine also has a push rod; while the new model engine also includes a valve bridge). The engine valve stroke loss mechanism of this embodiment includes a transmission mechanism 100 disposed on the rocker arm 10. One end of the rocker arm 10 is close to the engine cam 230, and the transmission mechanism 100 is close to the engine valve 301. The transmission mechanism 100 includes a transmission cam 102. The rotation of the transmission cam 102 generates a clearance 110 (separation, see Figure 1 ) with the engine valve 301, changing (losing) the motion transmitted from the engine cam 230 to the engine valve 301 through the rocker arm 10.

[0060] It should be noted that the transmission mechanism 100 is disposed at one end of the rocker arm 10 close to the engine valve 301. When the transmission cam 102 rotates to different positions, the clearance in the engine valve drive system changes. Among them, when the base circle part 1021 of the transmission cam 102 rotates to the engine valve 301, a clearance is generated between the base circle part 1021 and the engine valve 301, and part or all of the stroke of the engine valve 301 is lost; when the convex part 1022 of the transmission cam 102 rotates close to the engine valve 301, the clearance is reduced or eliminated to increase or fully restore the motion of the engine valve 301.

[0061] The transmission mechanism 100 further includes a drive mechanism for rotating the transmission cam 102. The drive mechanism includes a spring-piston mechanism, a control valve (not shown), and a connecting pin 105. The drive piston 103 and the return spring 104 are located in the drive piston cavity. One end of the connecting pin 105 is connected to the transmission cam 102, and the other end is connected to the drive piston 103. One end of the drive piston cavity communicates with the hydraulic oil passage 107, and the return spring 104 is disposed at the other end of the drive piston cavity.

[0062] Figure 1 In the figure, the control valve is closed, there is no pressure in the hydraulic oil passage 107, the return spring 104 pushes the drive piston 103 to reset, and then rotates the transmission cam 102. At this time, the transmission cam 102 is in a small lift or zero lift state, so that a clearance 110 is generated between the transmission cam 102 and the valve 301, and the motion transmitted from the rocker arm 10 to the valve 301 is lost (partially lost or completely lost).

[0063] Figure 2 In the figure, the control valve is opened, pressure is generated in the hydraulic oil passage 107, the engine oil overcomes the force of the return spring 104 to push the drive piston 103 to move, rotates the transmission cam 102, so that the lift of the transmission cam 102 increases, and the clearance 110 generated by the transmission cam in the engine valve drive system is reduced or even disappears. The motion transmitted from the rocker arm 10 to the valve 301 increases or even fully recovers.

[0064] In addition, by changing the rotational position of the transmission cam 102, it is also possible to cause loss of valve stroke when the control valve is open, while there is no loss of stroke when the control valve is closed.

[0065] Embodiment 2

[0066] As Figure 3 , 4 shown, the main difference between this embodiment and the previous embodiment is that the transmission mechanism 100 is moved from the engine valve side to the engine cam side. The transmission mechanism 100 is disposed at one end of the rocker arm 10 close to the engine cam 230. When the transmission cam 102 rotates to different positions, the clearance in the engine valve drive system changes. Among them, when the base circle portion of the transmission cam 102 rotates close to the engine cam 230, a clearance is generated between the base circle portion and the engine cam 230, and part or all of the engine valve stroke is lost; when the convex portion of the transmission cam 102 rotates close to the engine cam 230, the clearance is reduced or eliminated to increase or fully restore the movement of the engine valve 300.

[0067] Figure 3 In, the control valve is closed, there is no pressure in the hydraulic oil passage 107, and the return spring 104 pushes the drive piston 103 to reset. At this time, the transmission cam 102 is in a small lift or zero lift state, so that a clearance 110 is generated between the transmission cam 102 and the engine cam 230, and the movement transmitted from the cam 230 to the rocker arm 10, the valve bridge 400 and the engine valve 300 is lost (partially lost or completely lost).

[0068] Figure 4 In, the control valve is opened, the hydraulic oil passage 107 generates pressure, pushes the drive piston 103 to move, and rotates the transmission cam 102, so that the lift from the transmission cam 102 to the cam 230 is increased, and the clearance 110 is reduced and even disappears. The movement transmitted from the cam 230 to the rocker arm 10, the valve bridge 400 and the engine valve 300 is increased and even fully restored.

[0069] In addition, by changing the rotational position of the transmission cam 102, it is also possible to cause loss of valve stroke when the control valve is open, while there is no loss of stroke when the control valve is closed.

[0070] Furthermore, the profile of the transmission cam 102 has different curvatures, including a section with equal curvature at the highest position of the profile lift ( Figure 5 ). Figure 5 The abscissa is the rotation angle of the transmission cam 102, and the ordinate is the cam lift (profile curve). The flat top of the highest lift has equal curvature.

[0071] Embodiment 3

[0072] AsFigure 6 , Figure 7 As shown in Figure 7 , the engine valve stroke loss mechanism includes a first rocker arm 10 that rotates around a first rocker arm shaft 205, a second rocker arm 210 that rotates relative to the first rocker arm 10, and a transmission mechanism 100. One end of the first rocker arm 10 is close to the engine valve 300. The second rocker arm 210 is rotatably connected to a second rocker arm shaft 120. One end of the second rocker arm 210, a roller 235, is close to the engine cam 230, and the other end has a working surface 211 and is close to the transmission mechanism 100 on the first rocker arm 10. The transmission mechanism 100 of this embodiment further includes a transmission piston 101 located between the transmission cam 102 and the working surface 211 of the second rocker arm. When the transmission cam 102 rotates to different positions, the relative position between the first rocker arm 10 and the second rocker arm 210 changes, and the motion transmitted from the engine cam 230 to the engine valve 300 is changed, resulting in a predetermined degree of loss of valve lift.

[0073] The operation process of this embodiment is as follows.

[0074] Figure 6 In Figure 6 , the control valve is closed, the pressure in the hydraulic oil passage is lost, and the return spring 104 pushes the drive piston 103 to reset. At this time, the cam 102 is in the large lift state, eliminating the clearance in the engine valve drive system, so that the transmission piston 101 is in the rightmost position and locked. The second rocker arm 210 cannot rotate relative to the first rocker arm 10 (locked), making the second rocker arm 210 and the first rocker arm 10 form a moving part that rotates around the first rocker arm shaft 205, transmitting the motion of the engine cam 230 to the valve bridge 400 and the engine valve 300. In addition, the valves 301 and 302 are biased on the valve seats by valve springs 311 and 312.

[0075] Figure 7 In Figure 7 state, when the control valve is opened, pressure is generated in the hydraulic oil passage 107, pushing the drive piston 103 to move, causing the transmission cam 102 to rotate to the small lift or zero lift position, generating a clearance in the engine valve drive system, so that the transmission piston 101 loses the support of the transmission cam 102 and can move to the left, releasing the working surface (end face) 211 of the second rocker arm 210. The second rocker arm 210 can rotate relative to the first rocker arm 10 around the second rocker arm shaft 120, so that the motion transmitted from the cam 230 to the second rocker arm 210 is lost, reducing and even eliminating the motion transmitted to the first rocker arm 10, the valve bridge 400, and the engine valve 300.

[0076] From the operation process of this embodiment, it can be found that at different rotation positions of the transmission cam 102, the force application positions where the working surface (end face) 211 of the second rocker arm 210 interacts with the transmission mechanism 100 on the first rocker arm 10 are different. The movement of the working surface (end face) 211 of the second rocker arm 210 in its normal direction (the same as the movement direction of the transmission piston) is less than the movement in its tangential direction (perpendicular to the movement direction of the transmission piston). This means that a smaller stroke of the transmission piston 101 can absorb a larger lift of the engine cam 230, making the valve lift loss mechanism of the present utility model more compact.

[0077] In one example, the situation where the movement of the working surface 211 of the second rocker arm 210 in its normal direction is less than the movement in its tangential direction includes, but is not limited to: the normal force at the contact position is less than the tangential force at the contact position.

[0078] Similarly, by changing the rotation position of the transmission cam 102, different valve lift loss effects can also be produced when the control valve is opened or closed.

[0079] In this embodiment, it further includes an anti - fly - off spring 212, and the anti - fly - off spring 212 pushes the second rocker arm 210 towards the engine cam 230.

[0080] In this embodiment, it further includes a stop mechanism, and the stop mechanism is used to limit the relative rotation of the first rocker arm and the second rocker arm on the shaft.

[0081] As Figure 6 、 Figure 7 shown, the boss 213 is used for stopping when the second rocker arm 210 rotates clockwise, and the boss 214 is used for stopping when the second rocker arm 210 rotates counter - clockwise during the idle stroke.

[0082] Embodiment 4

[0083] The valve stroke loss mechanism of this embodiment further includes a valve clearance adjustment mechanism.

[0084] As Figure 8 shown, the roller 235 is installed on the adjustment piston 236, and the adjustment bolt 238 is used to adjust the position of the roller relative to the rocker arm 10, so as to ensure the accuracy of the clearance 110 between the transmission cam 102 and the valve 301. The lock nut 239 locks the adjustment bolt 238 to prevent it from loosening after adjustment. The anti - fly - off spring 237 generates a force between the rocker arm 10 and the adjustment piston 236 to keep it in contact with the cam 230 and avoid flying off. Although not shown in the figure, the valve clearance adjustment mechanism here further includes an anti - rotation mechanism for preventing the adjustment piston 236 from rotating and a limit mechanism for limiting the stroke of the adjustment piston 236.

[0085] The above description includes many different specific embodiments, which should not be regarded as a limitation on the scope of the present utility model, but rather as some specific examples representing the present utility model, from which many other variations are possible. For example, the engine valve stroke loss mechanism shown here can be used not only in overhead cam engines but also in pushrod / pushrod tube engines; it can open not only single valves but also double valves; it can be used not only to drive exhaust valves but also to drive intake valves; the number, size, shape, and phase of the cams contained can all be changed.

[0086] Moreover, the types of valve stroke loss mechanisms can also be diverse. In addition to the split (first and second rocker arms) rocker arm of the present application, it can also be an integral hydraulic special braking rocker arm, a fixed chain braking rocker arm, etc.

[0087] The embodiment also provides an engine, including the above-mentioned valve stroke loss mechanism.

[0088] The embodiment also provides a vehicle, including the above-mentioned engine.

[0089] The reference to "an example", "an embodiment", or "one embodiment" throughout the specification means that the specific features, structures, or characteristics described in connection with the embodiment are included in at least one embodiment. Therefore, the appearances of "an example", "in an embodiment", or "in one embodiment" in various places throughout the specification do not necessarily all refer to the same embodiment. Additionally, the specific features, structures, or characteristics can be combined in any manner in one or more embodiments.

[0090] The above embodiments are only illustrative of the principles and effects of the present utility model and are not intended to limit the present utility model. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present utility model. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present utility model should still be covered by the claims of the present utility model.

Claims

1. A valve stroke loss mechanism for an engine, characterized in that, It includes a transmission mechanism integrated within an engine valve drive system. The transmission mechanism includes a transmission cam, and the rotation of the transmission cam generates a clearance within the engine valve drive system, resulting in partial or complete loss of the engine valve stroke.

2. The valve stroke loss mechanism of the engine according to claim 1, characterized in that: The transmission cam includes a base circle portion and a boss portion. The rotation of the transmission cam causes the base circle portion to generate a clearance within the engine valve drive system, and causes the boss portion to reduce or eliminate the clearance within the engine valve drive system.

3. The valve stroke loss mechanism of the engine according to claim 1, characterized in that: The contour of the transmission cam has different curvatures, including an equal curvature which is set in a section of the highest position of the contour.

4. The valve stroke loss mechanism of the engine according to claim 1, characterized in that: The transmission mechanism further includes a drive mechanism for rotating the transmission cam. The drive mechanism includes a spring-piston mechanism, and the spring-piston mechanism includes a drive piston and a return spring.

5. The valve stroke loss mechanism of the engine according to claim 4, characterized in that: The return spring pushes the drive piston to move, thereby rotating the transmission cam. The clearance generated by the transmission cam within the engine valve drive system results in loss of the engine valve stroke; engine oil overcomes the force of the return spring to push the drive piston to move, thereby rotating the transmission cam, and the clearance generated by the transmission cam within the engine valve drive system is reduced or eliminated to increase or fully restore the movement of the engine valve.

6. The valve stroke loss mechanism of the engine according to claim 4, characterized in that: The transmission mechanism further includes a connecting pin. One end of the connecting pin is connected to the transmission cam, and the other end of the connecting pin is connected to the drive piston.

7. The valve stroke loss mechanism of the engine according to claim 1, characterized in that: The engine valve drive system includes a rocker arm. The transmission mechanism is arranged on the rocker arm of the engine. When the transmission cam rotates to different positions, the clearance within the engine valve drive system changes, and the movement transmitted from the engine cam to the engine valve is changed, resulting in a predetermined degree of loss of the lift of the engine valve.

8. The valve stroke loss mechanism of the engine according to claim 7, characterized in that: The engine valve drive system further includes a valve clearance adjusting mechanism.

9. The valve stroke loss mechanism of the engine according to claim 7, characterized in that: The transmission mechanism is arranged at one end of the rocker arm close to the engine valve. When the transmission cam rotates to different positions, the clearance within the engine valve drive system changes, where when the base circle portion of the transmission cam rotates close to the engine valve, a clearance is generated between the base circle portion and the engine valve, resulting in partial or complete loss of the engine valve stroke; when the boss portion of the transmission cam rotates close to the engine valve, the clearance is reduced or eliminated to increase or fully restore the movement of the engine valve.

10. The valve stroke loss mechanism of the engine according to claim 7, characterized in that: The transmission mechanism is arranged at one end of the rocker arm close to the engine cam. When the transmission cam rotates to different positions, the clearance within the engine valve drive system changes, where when the base circle portion of the transmission cam rotates close to the engine cam, a clearance is generated between the base circle portion and the engine cam, resulting in partial or complete loss of the engine valve stroke; when the boss portion of the transmission cam rotates close to the engine cam, the clearance is reduced or eliminated to increase or fully restore the movement of the engine valve.

11. The valve stroke loss mechanism of the engine as claimed in claim 1, wherein the valve drive system of the engine includes a first rocker arm that rotates about a first axis and a second rocker arm that rotates relative to the first rocker arm. One end of the first rocker arm is close to the valve of the engine, and the second rocker arm is rotatably connected to a second axis, characterized in that: The described transmission mechanism is arranged on the first rocker arm and is in contact connection with one end of the second rocker arm. The other end of the second rocker arm is in contact connection with the cam of the engine. When the transmission cam of the transmission mechanism rotates to different positions, the relative position between the first rocker arm and the second rocker arm changes, and the motion transmitted by the engine cam to the engine valve is changed, and a predetermined degree of loss occurs in the lift of the engine valve.

12. The valve stroke loss mechanism of the engine according to claim 11, characterized in that: The valve drive system of the engine further includes an anti-flying-off spring, and the anti-flying-off spring pushes the second rocker arm towards the engine cam.

13. The valve stroke loss mechanism of the engine according to claim 11, characterized in that: The described transmission mechanism further includes a transmission piston, and the transmission piston is located between the transmission cam and the second rocker arm. When the transmission cam rotates to different positions, the force-bearing position where the end face of the second rocker arm interacts with the transmission piston changes, and the movement of the end face of the second rocker arm in its normal direction is less than the movement in its tangential direction.

14. The valve stroke loss mechanism of the engine according to claim 11, characterized in that: The valve drive system of the engine further includes a stop mechanism, and the stop mechanism is used to limit the relative rotation of the first rocker arm and the second rocker arm on the shaft.

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