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 invention relates to the field of machinery, in particular to the field of engine valve driving, and in particular to a valve stroke loss mechanism of an engine. Background Art

[0002] Conventional valve actuation for vehicle engines is well known in the prior art and has been used for more than 100 years. Conventional valve actuation uses conventional valve actuators (including rocker arms) to control the movement of the engine valves for conventional ignition operation of the engine. However, due to additional requirements for engine fuel efficiency, exhaust emissions and engine braking, more and more engines are using variable valve actuation, including engine cylinder deactivation that completely eliminates valve movement, and engine braking has also been widely adopted by commercial vehicle engines.

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

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

[0005] U.S. Patent No. 5,537,976 (1996) discloses another two-stroke engine braking device and method, which uses cam drive, hydraulic connection, high-speed solenoid valve and electronic control to achieve different valve movements to achieve 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. In addition to other problems of hydraulic drive, such as control of valve seating speed, cold start of the engine, etc., this invention has not been put into practical use.

[0006] U.S. Patent No. 6,293,248 (2001) disclosed another two-stroke engine braking device and method. In order to achieve two-stroke engine braking on a four-stroke engine, in addition to four cams, four rocker arms must be used: two exhaust rocker arms (one of which is used for braking) and two intake rocker arms (one of which is used for braking). The structure and control are very complicated, and hydraulic drive is also used to open the engine valve. Summary of the invention

[0007] The purpose of the present invention is to provide a valve stroke loss mechanism for an engine, so as to solve the technical problems in the prior art that the engine valve driving structure and control are complex, the reliability and durability of hydraulically driven valve opening are poor, and the application is limited.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] In a first aspect, the present invention provides a valve stroke loss mechanism for an engine, comprising a transmission mechanism integrated in the valve drive system of the engine, wherein the transmission mechanism comprises a transmission cam, and the rotation of the transmission cam generates a gap in the valve drive system of the engine, resulting in the loss of the valve stroke of the engine.

[0010] Furthermore, in the first aspect of the present invention, the valve stroke loss mechanism of the engine is provided, wherein the profile of the transmission cam has different curvatures, including a section of equal curvature at the highest position of the profile.

[0011] Furthermore, the first aspect of the present invention provides a valve stroke loss mechanism for an engine, wherein the valve stroke loss of the engine includes partial loss and complete loss.

[0012] Furthermore, the first aspect of the present invention provides a valve stroke loss mechanism for an engine, wherein the transmission mechanism also includes a driving mechanism for rotating a transmission cam, and the driving mechanism includes a spring-piston mechanism, and the spring-piston mechanism includes a driving piston and a return spring.

[0013] Furthermore, the first aspect of the present invention provides a valve stroke loss mechanism for an engine, wherein the transmission cam is rotatably mounted on the rocker arm of the engine, and when the transmission cam rotates to different positions, the clearance within the valve drive system of the engine changes, the movement transmitted to the valve by the engine cam is changed, and the valve lift is lost to a predetermined degree.

[0014] Furthermore, the valve stroke loss mechanism of the engine provided in the first aspect of the present invention further includes a valve clearance adjustment mechanism.

[0015] Furthermore, the first aspect of the present invention provides a valve stroke loss mechanism for an engine, wherein the valve drive system of the engine includes a first rocker arm rotating around a first axis and a second rocker arm rotating 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 the second axis, and is characterized in that: the transmission mechanism is placed on the first rocker arm and 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 is changed, the movement transmitted to the valve by the cam of the engine is changed, and the valve lift is lost to a predetermined degree.

[0016] Furthermore, the first aspect of the present invention provides a valve stroke loss mechanism for an engine, wherein the transmission mechanism also includes a transmission piston, and the transmission piston is located between a transmission cam and a second rocker arm. When the transmission cam rotates to different positions, the force position of the interaction between the end face of the second rocker arm and the transmission piston changes, and the movement of the end face of the second rocker arm in its normal direction is smaller than the movement in its tangential direction.

[0017] Furthermore, the valve stroke loss mechanism of the engine provided by the first aspect of the present invention further includes an anti-fly-off spring, and the anti-fly-off spring pushes the second rocker arm toward the cam of the engine.

[0018] Furthermore, the valve stroke loss mechanism of the engine provided by the first aspect of the present invention further includes a stop mechanism, wherein the stop mechanism is used to limit the relative rotation of the first rocker arm and the second rocker arm on the shaft.

[0019] A second aspect of the present invention provides a valve stroke loss mechanism for an engine, comprising a transmission mechanism integrated in the engine valve drive system, wherein the transmission mechanism comprises a transmission cam, and rotation of the transmission cam generates a gap in the engine valve drive system, resulting in partial or complete loss of the engine valve stroke.

[0020] Optionally, the transmission cam includes a base circle portion and a boss portion, and rotation of the transmission cam causes the base circle portion to generate a gap in the engine valve drive system, and causes the boss portion to reduce or eliminate the gap in the engine valve drive system.

[0021] Optionally, the profile of the transmission cam has different curvatures, and the curvatures include constant curvatures, and the constant curvature is arranged in a region at a highest position of the profile.

[0022] Optionally, the transmission mechanism further comprises a driving mechanism for rotating the transmission cam, wherein the driving mechanism comprises a spring-piston mechanism, and the spring-piston mechanism comprises a driving piston and a return spring.

[0023] Optionally, the return spring pushes the drive piston to move, thereby causing the transmission cam to rotate, and the gap generated by the transmission cam in the engine valve drive system causes the engine valve stroke to be lost; the engine oil overcomes the force of the return spring to push the drive piston to move, thereby causing the transmission cam to rotate, and the gap generated by the transmission cam in the engine valve drive system is reduced or disappears, so as to increase or completely restore the movement of the engine valve.

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

[0025] Optionally, the engine valve drive system includes a rocker arm, and the transmission mechanism is placed 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 movement transmitted to the engine valve by the engine cam is changed, and the lift of the engine valve is lost to a predetermined degree.

[0026] Optionally, the engine valve drive system also includes a valve clearance adjustment mechanism.

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

[0028] When the base circle portion of the transmission cam rotates close to the engine valve, a gap is generated between the base circle portion and the engine valve, and the engine valve stroke is partially or 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 completely 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, and when the transmission cam rotates to different positions, the clearance in the engine valve drive system changes, wherein

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

[0032] When the boss portion of the transmission cam rotates close to the engine cam, the gap is reduced or eliminated to increase or completely restore the movement of the engine valve.

[0033] Optionally, the valve drive system of the engine includes a first rocker arm rotating around a first axis and a second rocker arm rotating relative to the first rocker arm, one end of the first rocker arm is close to the engine valve, and the second rocker arm is rotatably connected to the second axis, and is characterized in that: the transmission mechanism is placed on the first rocker arm and is in contact with one end of the second rocker arm, and the other end of the second rocker arm is in contact with a 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 is changed, the movement transmitted to the engine valve by the engine cam is changed, and the lift of the engine valve is lost to a predetermined degree.

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

[0035] Optionally, the transmission mechanism also includes a transmission piston, which is located between the transmission cam and the second rocker arm. When the transmission cam rotates to different positions, the force position of the interaction between the end face of the second rocker arm and the transmission piston changes, and the movement of the end face of the second rocker arm in its normal direction is smaller than the movement in its tangential direction.

[0036] Optionally, the valve drive system of the engine further comprises 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.

[0037] A third aspect of the present invention provides an engine, which includes the rocker arm mechanism provided in the first and second aspects of the present invention.

[0038] A fourth aspect of the present invention provides an automobile comprising the above-mentioned engine.

[0039] Beneficial effects of the present invention

[0040] Compared with the prior art, the effect of the present invention is positive and obvious. The mechanism of the present invention includes a transmission cam, through which the movement of the transmission cam generates or loses the movement of the engine valve, realizing the conversion between engine ignition and engine cylinder deactivation or braking, etc., and 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 lifting and shrinking amount and movement speed of the transmission piston generated are controllable (according to the design of the cam profile as needed), which can be applied to variable valve drive of large-lift engines, including engine cylinder deactivation and large-stroke engine braking that cancel the entire valve lift, as well as applications in scenarios with narrow installation space.

[0041] In addition, the rocker mechanism of the present invention can be a rocker or composed of a first rocker and a second rocker. The first rocker and the second rocker are connected (locked) or separated (loosened) with each other through the conversion of the working curved surface and the transmission piston, generating or losing the valve movement of the engine, realizing the conversion between engine ignition and engine cylinder stop or braking, etc., and by designing the shape of the working curved surface, the effect of generating a larger idle stroke (stroke loss) with a smaller stroke of the transmission piston is achieved. Therefore, it has the advantages of simple and reliable structure, easy manufacturing and assembly, and wide application. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[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 invention;

[0046] Figure 5 is a schematic diagram of the transmission cam profile curve of the present invention;

[0047] Figure 6 Schematic diagram of a valve stroke loss mechanism embodiment of the present invention in a stroke-free state;

[0048] Figure 7 It is a schematic diagram of a valve stroke loss state in an embodiment of the valve stroke loss mechanism of the present invention;

[0049] Figure 8 It is a schematic diagram of the adjustable valve clearance in the valve stroke loss mechanism embodiment of the present invention. DETAILED DESCRIPTION

[0050] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0051] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that can be implemented in the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. 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 embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0053] Example 1

[0054] In one example, an engine valve stroke loss mechanism includes a transmission mechanism, which 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 loss of 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 causes the base circle portion 1021 to generate a gap in the engine valve drive system, and causes the boss portion 1022 to reduce or eliminate the gap in the engine valve drive system.

[0057] In one example, engine valve travel loss includes partial loss and complete loss.

[0058] In one example, an engine valve drive system includes a rocker arm, and a transmission mechanism is placed on the rocker arm of the engine. When the transmission cam rotates to different positions, the clearance within the engine valve drive system changes, 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 degree.

[0059] like Figure 1 , 2As shown, the engine valve travel loss mechanism includes the engine cam 230, the rocker arm 10 and the valve 301 (the old engine also has a push rod; while the new engine also includes a valve bridge). The engine valve travel loss mechanism of this embodiment includes a transmission mechanism 100 arranged 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 gap 110 (separation, see Figure 1 ), changing (losing) the movement of the engine cam 230 transmitted to the engine valve 301 through the rocker arm 10.

[0060] It should be noted that the transmission mechanism 100 is arranged at one end of the rocker arm 10 close to the engine valve 301. When the transmission cam 102 rotates to different positions, the gap in the engine valve drive system changes, wherein when the base circle part 1021 of the transmission cam 102 rotates to the engine valve 301, a gap is generated between the base circle part 1021 and the engine valve 301, and the stroke of the engine valve 301 is partially lost or completely lost; when the boss part 1022 of the transmission cam 102 rotates to be close to the engine valve 301, the gap is reduced or disappears to increase or completely restore the movement of the engine valve 301.

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

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

[0063] Figure 2 In the process, the control valve is opened, pressure is generated in the hydraulic oil channel 107, and the engine oil overcomes the force of the return spring 104 to push the driving piston 103 to move, so that the transmission cam 102 rotates, thereby increasing the lift of the transmission cam 102, and the gap 110 generated by the transmission cam in the engine valve drive system is reduced or even disappears. As a result, the movement transmitted to the valve 301 by the rocker arm 10 is increased or even completely restored.

[0064] In addition, by changing the rotational position of the transmission cam 102, the valve stroke can be lost when the control valve is opened, while the stroke is not lost when the control valve is closed.

[0065] Example 2

[0066] like Figure 3 , 4 As 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 arranged at one end of the rocker arm 10 close to the engine cam 230. When the transmission cam 102 rotates to different positions, the gap in the engine valve drive system changes. When the base circle part of the transmission cam 102 rotates close to the engine cam 230, a gap is generated between the base circle part and the engine cam 230, and the engine valve stroke is partially lost or completely lost; when the boss part of the transmission cam 102 rotates close to the engine cam 230, the gap is reduced or disappears, so as to increase or completely restore the movement of the engine valve 300.

[0067] Figure 3 In the process, the control valve is closed, there is no pressure in the hydraulic oil channel 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 gap 110 is generated between the transmission cam 102 and the engine cam 230, so that the movement transmitted by the cam 230 to the rocker arm 10, the valve bridge 400 and the engine valve 300 is lost (partially or completely).

[0068] Figure 4 In the process, the control valve is opened, the hydraulic oil channel 107 generates pressure, which pushes the driving piston 103 to move, causing the transmission cam 102 to rotate, thereby increasing the lift from the transmission cam 102 to the cam 230, and reducing or even eliminating the gap 110. This increases or even completely restores the movement transmitted by the cam 230 to the rocker arm 10, the valve bridge 400 and the engine valve 300.

[0069] In addition, by changing the rotational position of the transmission cam 102, the valve stroke can be lost when the control valve is opened, while the stroke is not lost when the control valve is closed.

[0070] In addition, the profile of the transmission cam 102 has different curvatures, including a section of constant curvature ( Figure 5 ). Figure 5 The horizontal axis is the rotation angle of the transmission cam 102, and the vertical axis is the cam lift (contour curve). The flat top of the highest lift has constant curvature.

[0071] Example 3

[0072] like Figure 6 , Figure 7 As shown, the engine valve stroke loss mechanism includes a first rocker arm 10 rotating around a first rocker arm shaft 205, a second rocker arm 210 rotating 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 the second rocker arm shaft 120, a roller 235 at one end of the second rocker arm 210 is close to the engine cam 230, and the other end has a working curved surface 211 and is close to the transmission mechanism 100 on the first rocker arm 10. The transmission mechanism 100 of this embodiment also includes a transmission piston 101, which is located between the transmission cam 102 and the second rocker arm working curved surface 211. 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, the motion transmitted to the engine valve 300 by the engine cam 230 is changed, and the valve lift is lost to a predetermined degree.

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

[0074] Figure 6 In the process, the control valve is closed, the hydraulic oil channel loses pressure, and the return spring 104 pushes the driving piston 103 to return. At this time, the cam 102 is in a large lift state, eliminating the gap in the engine valve drive system, so that the transmission piston 101 is in the rightmost position and locked, and the second rocker arm 210 cannot rotate relative to the first rocker arm 10 (locked), so that the second rocker arm 210 and the first rocker arm 10 form a moving part rotating around the first rocker arm shaft 205, and the movement of the engine cam 230 is transmitted 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 the state, when the control valve is opened, pressure is generated in the hydraulic oil channel 107, pushing the drive piston 103 to move, causing the transmission cam 102 to rotate to a small lift or zero lift position, and generating a gap 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, loosening from the working curved surface (end surface) 211 of the second rocker arm 210. The second rocker arm 210 can rotate around the second rocker arm shaft 120 relative to the first rocker arm 10, so that the motion transmitted to the second rocker arm 210 by the cam 230 is lost, reducing or even eliminating the motion transmitted to the first rocker arm 10, the valve bridge 400 and the engine valve 300.

[0076] It can be found from the operation process of this embodiment that at different rotation positions of the transmission cam 102, the working curved surface (end surface) 211 of the second rocker arm 210 and the transmission mechanism 100 on the first rocker arm 10 have different force positions where they interact, and the working curved surface (end surface) 211 of the second rocker arm 210 has a smaller movement in its normal direction (same as the movement direction of the transmission piston) than 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 invention more compact.

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

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

[0079] In this embodiment, an anti-fly-off spring 212 is further included, and the anti-fly-off spring 212 pushes the second rocker arm 210 toward the cam 230 of the engine.

[0080] In this embodiment, a stop mechanism is also included, and the stop mechanism is used to limit the mutual rotation of the first rocker arm and the second rocker arm on the shaft.

[0081] like Figure 6 , Figure 7 As shown, the boss 213 is used to stop the second rocker arm 210 when it rotates clockwise, and the boss 214 is used to stop the second rocker arm 210 when it rotates counterclockwise during idle travel.

[0082] Example 4

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

[0084] like Figure 8 As 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 that the gap 110 between the transmission cam 102 and the valve 301 is accurate. The locking nut 239 locks the adjustment bolt 238 to prevent it from loosening after the adjustment is completed. The anti-fly-off spring 237 generates a force between the rocker arm 10 and the adjustment piston 236, so that it keeps in contact with the cam 230 to prevent it from flying off. Although not shown in the figure, the valve clearance adjustment mechanism here also includes an anti-rotation mechanism to prevent the adjustment piston 236 from rotating and a limit mechanism to limit the stroke of the adjustment piston 236.

[0085] The above description includes many different specific embodiments, which should not be regarded as limiting the scope of the present invention, but as some specific examples representing the present invention, and many other variations may be generated therefrom. For example, the engine valve stroke loss mechanism shown here can be used not only for overhead cam engines, but also for pushrod / push 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 bosses contained in the cam can be changed.

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

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

[0088] The embodiment further provides a car, comprising the above-mentioned engine.

[0089] References throughout the specification to "an example," "one embodiment," or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearance of "an example," "in one embodiment," or "in an embodiment" in various places throughout the specification need not all refer to the same embodiment. Additionally, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0090] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A valve stroke loss mechanism for an engine, characterized in that: The invention comprises a transmission mechanism integrated in the engine valve driving system, wherein the transmission mechanism comprises a transmission cam, and the rotation of the transmission cam generates a gap in the engine valve driving system, resulting in partial or complete loss of the engine valve stroke. Optionally, the transmission cam includes a base circle portion and a boss portion, and rotation of the transmission cam causes the base circle portion to generate a gap in the engine valve drive system, and causes the boss portion to reduce or eliminate the gap in the engine valve drive system.

2. The engine valve stroke loss mechanism according to claim 1, characterized in that: The profile of the transmission cam has different curvatures, wherein the curvatures include a constant curvature, and the constant curvature is arranged in a section of a highest position of the profile.

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

4. The engine valve stroke loss mechanism according to claim 3, characterized in that: The return spring pushes the drive piston to move, thereby causing the transmission cam to rotate. The gap generated by the transmission cam in the engine valve drive system causes the loss of the engine valve stroke; the engine oil overcomes the force of the return spring to push the drive piston to move, thereby causing the transmission cam to rotate. The gap generated by the transmission cam in the engine valve drive system is reduced or disappears, thereby increasing or completely restoring the movement of the engine valve. Optionally, the transmission mechanism further includes a connecting pin, one end of which is connected to the transmission cam, and the other end of which is connected to the driving piston.

5. The engine valve stroke loss mechanism according to claim 1, characterized in that: The engine valve drive system includes a rocker arm, and the transmission mechanism is placed 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 movement transmitted to the engine valve by the engine cam is changed, and the lift of the engine valve is lost to a predetermined degree. Optionally, the engine valve drive system also includes a valve clearance adjustment mechanism.

6. The engine valve stroke loss mechanism according to claim 5, 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 in the engine valve drive system changes. When the base circle portion of the transmission cam rotates close to the engine valve, a gap is generated between the base circle portion and the engine valve, and the engine valve stroke is partially or completely lost; When the boss portion of the transmission cam rotates close to the engine valve, the clearance is reduced or eliminated to increase or completely restore the movement of the engine valve.

7. The engine valve loss mechanism according to claim 5, 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 in the engine valve drive system changes. When the base circle portion of the transmission cam rotates close to the engine cam, a gap is generated between the base circle portion and the engine cam, and the engine valve stroke is partially or completely lost; When the boss portion of the transmission cam rotates close to the engine cam, the gap is reduced or eliminated to increase or completely restore the movement of the engine valve.

8. The engine valve stroke loss mechanism as claimed in claim 1, wherein the engine valve drive system comprises a first rocker arm rotating around a first axis and a second rocker arm rotating relative to the first rocker arm, one end of the first rocker arm is close to the engine valve, and the second rocker arm is rotatably connected to the second axis, characterized in that: The transmission mechanism is placed on the first rocker arm and is in contact with one end of the second rocker arm. The other end of the second rocker arm is in contact 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, the movement transmitted to the engine valve by the engine cam is changed, and the lift of the engine valve is lost to a predetermined degree. Optionally, the valve drive system of the engine further comprises an anti-fly-off spring, wherein the anti-fly-off spring pushes the second rocker arm toward the engine cam.

9. The engine valve stroke loss mechanism according to claim 8, characterized in that: The transmission mechanism also includes a transmission piston, which is located between the transmission cam and the second rocker arm. When the transmission cam rotates to different positions, the force position of the interaction between the end face of the second rocker arm and the transmission piston changes, and the movement of the end face of the second rocker arm in its normal direction is smaller than the movement in its tangential direction.

10. The engine valve stroke loss mechanism according to claim 8, characterized in that: The valve drive system of the engine also includes a stop mechanism, which is used to limit the mutual rotation of the first rocker arm and the second rocker arm on the shaft.

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