Rocker arm mechanism for driving variable valve of engine

Abstract

A rocker arm mechanism for variable valve driving of an engine comprises a front rocker arm rotating around a front rocker arm shaft and a rear rocker arm rotating relative to the front rocker arm, one end of the front rocker arm is close to a valve of the engine, and the rear rocker arm is rotatably connected to a rear rocker arm shaft. One end of the rear rocker arm is close to a cam of the engine, the other end of the rear rocker arm is provided with a working curved surface and is close to the transmission mechanism on the front rocker arm, the cam of the engine drives the rear rocker arm, and the working curved surface of the rear rocker arm acts on the transmission mechanism on the front rocker arm; (1) the stress position of the interaction of the working curved surface and the transmission mechanism is changed, the relative position of the front rocker arm and the rear rocker arm and the movement transmitted to an engine valve by an engine cam are changed, and (2) the movement of the working curved surface in the normal direction is smaller than the movement of the working curved surface in the tangential direction.

Description

Technical Field

[0001] The utility model relates to the field of engine valve drive, and particularly to a rocker mechanism for variable valve drive of an engine. Background Art

[0002] In the prior art, the conventional valve drive of vehicle engines is well-known and has been applied for more than a 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. In this invention, the overhead cam acts 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 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, in this invention, the overhead cam acts 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. By means of cam drive, hydraulic connection, high-speed solenoid valves, and electronic control, different valve movements are achieved to 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 US 6,293,248 (2001) discloses yet another device and method for two-stroke engine braking. 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 for braking) and two intake rocker arms (one of which is for braking). The structure and control are both very complex, and hydraulic drive is also used to open the engine valve. Summary of the Invention

[0007] The utility model aims to provide a rocker arm mechanism for variable valve drive of an engine, so as to solve the technical problems in the prior art that the valve drive structure is complex, the reliability and durability of the hydraulic drive for opening the valve are poor, and the application is limited.

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

[0009] In a first aspect of the utility model, a rocker arm mechanism for variable valve drive of an engine is provided. The rocker arm mechanism includes: a front rocker arm, a rear rocker arm and a transmission mechanism. One end of the front rocker arm is close to the engine valve, and one end of the rear rocker arm is close to the engine cam. Among them,

[0010] The transmission mechanism is arranged at the other end of the front rocker arm, and a working surface is arranged at the other end of the rear rocker arm; or the transmission mechanism is arranged at the other end of the rear rocker arm, and a working surface is arranged at the other end of the front rocker arm;

[0011] The change in the force application position where the transmission mechanism in one of the front rocker arm or the rear rocker arm interacts with the working surface of the other rocker arm causes the front rocker arm and the rear rocker arm to be in a mutually locked or disconnected state, so as to change the motion transmitted from the engine cam to the engine valve.

[0012] Optionally, the rocker arm mechanism further includes an anti-flying-off spring, and the anti-flying-off spring pushes the rear rocker arm towards the engine cam.

[0013] Optionally, an anti-jumping spring is further included, and the anti-jumping spring pushes the rocker arm including the working surface towards the cam or the valve side.

[0014] Optionally, the transmission mechanism and the working surface satisfy one or more of the following conditions:

[0015] (1) The change in the force application position where the working surface interacts with the transmission mechanism changes the relative position of the front rocker arm and the rear rocker arm and the motion transmitted from the engine cam to the engine valve;

[0016] (2) The motion of the working surface in its normal direction is less than the motion in its tangential direction.

[0017] Optionally, the rocker arm mechanism further includes a front rocker arm shaft and a rear rocker arm shaft, among which

[0018] When the front rocker arm and the rear rocker arm are in the mutually locked state, the rear rocker arm cannot rotate relative to the front rocker arm, and the front rocker arm and the rear rocker arm rotate as a whole around the front rocker arm shaft, and the motion of the engine cam is transmitted to the engine valve;

[0019] When the front rocker arm and the rear rocker arm are in the disconnected state, the rear rocker arm can rotate relative to the front rocker arm, the rear rocker arm rotates around the rear rocker arm shaft, and the movement of the engine cam is at least partially not transmitted to the engine valve.

[0020] Optionally, the transmission mechanism includes a movable transmission piston, one end of the transmission piston abuts against the working surface, and when the transmission piston is in different positions, the force application position where one end of the transmission piston interacts with the working surface changes.

[0021] Optionally, the positions of the movable transmission piston include a locked position and an unlocked position, where

[0022] When the front rocker arm and the rear rocker arm are in the mutually locked state, the transmission piston is in the locked position and is stopped;

[0023] When the front rocker arm and the rear rocker arm are in the disconnected state, the transmission piston moves between the locked position and the unlocked position.

[0024] Optionally, the transmission mechanism further includes a rotating gear ring, the rotating gear ring includes a tooth end, the transmission piston includes a tooth end and a non-tooth end, the tooth end of the rotating gear ring is movably connected to the tooth end of the transmission piston, the non-tooth end of the transmission piston abuts against the working surface, the rotation of the rotating gear ring causes a change in the relative position between the tooth end of the rotating gear ring and the tooth end of the transmission piston, the contact position between the non-tooth end of the transmission piston and the working surface changes, and the movement transmitted from the engine cam to the engine valve is changed.

[0025] Optionally, the tooth peaks of the tooth end of the transmission piston are aligned with the tooth peaks of the tooth end of the rotating gear ring so that the transmission piston is stopped. When the transmission piston is in the locked position and is stopped, the front rocker arm and the rear rocker arm are in the mutually locked state; the tooth peaks of the tooth end of the transmission piston are aligned with the tooth valleys of the tooth end of the rotating gear ring, the transmission piston moves between the locked position and the unlocked position, and the front rocker arm and the rear rocker arm are in the disconnected state.

[0026] Optionally, the transmission mechanism further includes a linkage mechanism, one end of the transmission piston is connected to the linkage mechanism, and the other end of the transmission piston abuts against the working surface. The telescopic movement of the linkage mechanism drives the transmission piston to move, so that the contact position between the transmission piston and the working surface changes, and the movement transmitted from the engine cam to the valve is changed.

[0027] Optionally, two connecting rods of the connecting rod mechanism are in the same straight line to stop the transmission piston. When the transmission piston is in the locked position and stopped, the front rocker arm and the rear rocker arm are in the interlocked state; the two connecting rods of the connecting rod mechanism are bent, the transmission piston moves between the locked position and the unlocked position, and the front rocker arm and the rear rocker arm are in the disconnected state.

[0028] Optionally, the transmission mechanism further includes a built-in spring. One end of the transmission piston is connected to the built-in spring, and the other end of the transmission piston abuts against the working surface. The built-in spring is disposed in the accommodation cavity; the accommodation cavity is filled with engine oil to stop the transmission piston. When the transmission piston is in the locked position and stopped, the front rocker arm and the rear rocker arm are in the interlocked state; the accommodation cavity is not filled with engine oil, the transmission piston moves between the locked position and the unlocked position, and the front rocker arm and the rear rocker arm are in the disconnected state.

[0029] Optionally, the working surface is in contact connection with the transmission piston and is designed as a predetermined contour surface, and the predetermined contour surface is any one of a positive curvature, a negative curvature, and a plane;

[0030] Preferably, the working surface of the toothed transmission piston is any one of a positive curvature, a negative curvature, and a plane;

[0031] Preferably, through the predetermined contour design of the working surface, the required contact point curvature and the follower piston speed element can be set at each point during the movement process.

[0032] Optionally, the rocker arm mechanism further includes a stop mechanism disposed on the front rocker arm or the rear rocker arm, and the stop mechanism is used to limit the relative rotation of the front rocker arm and the rear rocker arm on the shaft.

[0033] In a second aspect of the present invention, there is provided a rocker arm mechanism for an engine variable valve drive, including: a front rocker arm rotating around a front rocker arm shaft and a rear rocker arm rotating relative to the front rocker arm. One end of the front rocker arm is close to the valve of the engine. The rear rocker arm is rotatably connected to a rear rocker arm shaft. One end of the rear rocker arm is close to the cam of the engine, and the other end has a working surface and is close to the transmission mechanism on the front rocker arm. The cam of the engine drives the rear rocker arm, and the working surface of the rear rocker arm acts on the transmission mechanism on the front rocker arm, characterized in that (1) the force application position where the working surface interacts with the transmission mechanism changes, changing the relative positions of the front rocker arm and the rear rocker arm and the movement transmitted from the engine cam to the engine valve, and (2) the movement of the working surface in its normal direction is less than the movement in its tangential direction.

[0034] In the third aspect of the present utility model, a rocker arm mechanism for an engine variable valve drive is provided, including: a front rocker arm, a rear rocker arm, and a transmission mechanism. The transmission mechanism is disposed inside the front rocker arm or the rear rocker arm. One end of the front rocker arm is close to the valve of the engine, and one end of the rear rocker arm is close to the cam of the engine. The other end of the front rocker arm or the rear rocker arm has a working surface. The change in the force application position where the transmission mechanism inside one rocker arm interacts with the working surface of the other rocker arm causes the front rocker arm and the rear rocker arm to be in a mutually locked or disconnected state, thereby changing the motion transmitted from the engine cam to the engine valve.

[0035] Further, for the rocker arm mechanisms provided in the second and third aspects of the present utility model, the transmission mechanism includes a toothed transmission piston and a rotating toothed ring. The tooth end of the rotating toothed ring is connected to the tooth end of the toothed transmission piston. The other end of the toothed transmission piston is in contact connection with the working surface. The rotation of the rotating toothed ring causes a change in the relative position between the tooth end of the rotating toothed ring and the tooth end of the toothed transmission piston, and the contact position between the toothed transmission piston and the working surface changes, thereby changing the motion transmitted from the engine cam to the valve.

[0036] Further, for the rocker arm mechanisms provided in the second and third aspects of the present utility model, the working surface is in contact connection with the toothed transmission piston and is designed as a predetermined contour surface, and the predetermined contour surface can be any one of a positive curvature, a negative curvature, and a plane.

[0037] Further, for the rocker arm mechanisms provided in the second and third aspects of the present utility model, the working surface of the toothed transmission piston can also be a positive curvature, a negative curvature, or a plane.

[0038] Further, for the rocker arm mechanisms provided in the second and third aspects of the present utility model, through the predetermined contour design of the working surface, the required contact point curvature and the follower piston speed elements can be set at each point during the motion process.

[0039] Further, for the rocker arm mechanisms provided in the second and third aspects of the present utility model, the transmission mechanism further includes a link mechanism and a transmission piston. One end of the link mechanism is connected to the transmission piston. The end face of the transmission piston is in contact connection with the working surface of the rocker arm. The telescopic movement of the link mechanism drives the transmission piston to move, causing the contact position between the transmission piston and the working surface to change.

[0040] Further, for the rocker arm mechanisms provided in the second and third aspects of the present utility model, the transmission mechanism has a piston cavity and a driving unit, and the driving unit is used to drive the transmission piston to move inside the piston cavity.

[0041] Further, for the rocker arm mechanism provided in the second and third aspects of the present utility model, the drive unit includes a hydraulic control valve for controlling the movement of the transmission piston.

[0042] Further, for the rocker arm mechanism provided in the second and third aspects of the present utility model, it further includes an anti-flying-off spring, and the anti-flying-off spring pushes the rear rocker arm towards the cam of the engine.

[0043] Further, for the rocker arm mechanism provided in the second and third aspects of the present utility model, it further includes an anti-jumping spring, and the anti-jumping spring pushes the rocker arm with the working surface towards the cam or the valve side.

[0044] Further, for the rocker arm mechanism provided in the second and third aspects of the present utility model, it further includes a stop mechanism, and the stop mechanism is used to limit the relative rotation of the front rocker arm and the rear rocker arm on the shaft.

[0045] In the fourth aspect of the present utility model, there is provided an engine, which includes the above-mentioned rocker arm mechanism provided in the first, second, and third aspects of the present utility model.

[0046] In the fifth aspect of the present utility model, there is provided a vehicle, which includes the above-mentioned engine.

[0047] Advantages of the present utility model:

[0048] Compared with the prior art, the effects of the present utility model are positive and obvious. The rocker arm mechanism of the present utility model includes a toothed transmission piston and a rotating toothed ring. The rotation of the rotating toothed ring changes the relative position between the tooth end of the rotating toothed ring and the tooth end of the toothed transmission piston, and the contact position between the toothed transmission piston and the working surface changes, generating or losing the valve movement of the engine, 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. Especially for the simple and reliable structure, it can be applied to the variable valve drive of engines with large lift, including engine cylinder shutdown with the entire valve lift cancelled and engine braking with large stroke, as well as applications in scenarios with limited installation space.

[0049] In addition, the rocker arm mechanism of the present utility model is composed of a front rocker arm and a rear rocker arm. Through the conversion between the working surface and the transmission piston, the front rocker arm and the rear rocker arm are connected or separated, generating or losing the valve movement of the engine, realizing the conversion between engine ignition and engine cylinder shutdown or braking, etc. By designing the shape of the working surface, the effect that a relatively small stroke of the transmission piston can achieve a relatively large idle stroke (losing movement) can be achieved. Therefore, it has the advantages of simple and reliable structure, easy manufacturing and assembly, and wide application. Description of the Drawings

[0050] Figure 1It is a schematic diagram of the retracted state of the transmission mechanism with a gear ring in an embodiment of the rocker arm mechanism of the present utility model;

[0051] Figure 2 It is a schematic diagram of the extended state of the transmission mechanism with a gear ring in an embodiment of the rocker arm mechanism of the present utility model;

[0052] Figure 3 It is a schematic diagram of the extended state of the transmission mechanism with a connecting rod in an embodiment of the rocker arm mechanism of the present utility model;

[0053] Figure 4 It is a schematic diagram of the retracted state of the transmission mechanism with a connecting rod in an embodiment of the rocker arm mechanism of the present utility model;

[0054] Figure 5 It is a schematic diagram of the transmission mechanism with an anti - jump spring in an embodiment of the rocker arm mechanism of the present utility model. Detailed implementation manners

[0055] 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.

[0056] It should be noted that the structures, ratios, 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 the art to understand and read, and are not used to limit the limited conditions under which the present utility model can be implemented. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present utility model. At the same time, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "rear", etc. cited in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation to the embodiments of this application. At the same time, the terms "first", "second", "third" in this specification are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0057] The embodiments of the present utility model will be described in detail below in conjunction with the 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 construed as limiting the scope of the present utility model. For those conditions not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For those reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0058] Embodiment

[0059] In one example, a rocker arm mechanism for engine variable valve drive is provided, including: a front rocker arm that rotates around a front rocker arm shaft and a rear rocker arm that rotates relative to the front rocker arm. One end of the front rocker arm is close to the valve of the engine. The rear rocker arm is rotatably connected to a rear rocker arm shaft. One end of the rear rocker arm is close to the cam of the engine, and the other end has a working surface and is close to the transmission mechanism on the front rocker arm. The cam of the engine drives the rear rocker arm to rotate around the rear rocker arm shaft, and the working surface of the rear rocker arm acts on the transmission mechanism on the front rocker arm, having the following characteristics: (1) the force application position where the working surface interacts with the transmission mechanism changes, changing the rotation of the front rocker arm and the movement transmitted from the engine cam to the engine valve; (2) the movement of the working surface in its normal direction is less than the movement in its tangential direction.

[0060] In one example, a rocker arm mechanism for engine variable valve drive is provided, including: a front rocker arm, a rear rocker arm, and a transmission mechanism. The transmission mechanism is arranged inside the front rocker arm or the rear rocker arm. One end of the front rocker arm is close to the valve of the engine. One end of the rear rocker arm is close to the cam of the engine. The other end of the front rocker arm or the rear rocker arm has a working surface. The change in the force application position where the transmission mechanism in one rocker arm interacts with the working surface of the other rocker arm causes the front rocker arm and the rear rocker arm to be in a locked or disengaged state, changing the movement transmitted from the engine cam to the engine valve.

[0061] It should be noted that when the front rocker arm and the rear rocker arm are in a locked state, the rear rocker arm cannot rotate relative to the front rocker arm, and the front rocker arm and the rear rocker arm rotate as a whole around the front rocker arm shaft. The movement of the engine cam is transmitted to the engine valve to increase or fully restore the movement of the engine valve. When the front rocker arm and the rear rocker arm are in a disengaged state, the rear rocker arm can rotate relative to the front rocker arm, and the rear rocker arm rotates around the rear rocker arm shaft. At least part of the movement of the engine cam is not transmitted to the engine valve, resulting in partial or complete loss of the engine valve stroke.

[0062] Refer to Figures 1 to 5, the transmission mechanism 100 includes a movable transmission piston 101. One end of the transmission piston 101 abuts against the working surface 211. When the transmission piston 101 is in different positions, the force application positions where one end of the transmission piston 101 interacts with the working surface 211 change. The positions of the movable transmission piston 101 include a locking position ( Figure 2 , Figure 3 or Figure 5 the position where it is located) and a non-locking position ( Figure 1 and or Figure 4 the position where it is located). Among them, when the front rocker arm 10 and the rear rocker arm 210 are in a mutually locked state, the transmission piston 101 is in the locking position and is stopped; when the front rocker arm 10 and the rear rocker arm 210 are in a disconnected state, the transmission piston 101 moves between the locking position and the non-locking position.

[0063] As Figure 1 , Figure 2 shown, the transmission mechanism 100 includes a toothed transmission piston 101, a rotating gear ring 112 and a driving piston 113. The toothed end (tooth end) of the rotating gear ring 112 is connected to the tooth end of the toothed transmission piston 101. The other end (non-tooth end) of the toothed transmission piston 101 is in contact connection with the working surface 211 of the rear rocker arm 210. The spring 107 is located at the center of the rotating gear ring 112 and the toothed transmission piston 101 and tends to separate the tooth ends of the two (disengaged meshing position), which is conducive to the rotational switching of the rotating gear ring 112. The rotation of the rotating gear ring 112 causes the relative positions of the tooth end of the rotating gear ring 112 and the tooth end of the transmission piston 101 to change, and the contact position between the non-tooth end of the transmission piston 101 and the working surface 211 to change, and the movement transmitted from the engine cam to the engine valve is changed.

[0064] The tooth crest of the tooth end of the transmission piston 101 is aligned with the tooth crest of the tooth end of the rotating gear ring 112 so that the transmission piston 101 is stopped. When the transmission piston 101 is in the locking position and is stopped, the front rocker arm 10 and the rear rocker arm 210 are in a mutually locked state; the tooth crest of the tooth end of the transmission piston 101 is aligned with the tooth valley of the tooth end of the rotating gear ring 112, the transmission piston 101 moves between the locking position and the non-locking position, and the front rocker arm 10 and the rear rocker arm 210 are in a disconnected state.

[0065] The operation process is as follows. As Figure 1The shown transmission mechanism 100, when it is necessary to eliminate the valve movement (cylinder deactivation) of the engine, a control valve (not shown) opens the oil supply, and the engine oil supplies oil to the transmission mechanism 100 through an oil passage, pushing the driving piston 113. The driving piston 113 pushes the rotating gear ring 112 to rotate, causing a change in the relative position between the tooth end of the rotating gear ring 112 and the tooth end of the tooth-shaped transmission piston 101 (for example, switching from tooth tip against tooth tip to tooth tip against tooth valley). The tooth-shaped transmission piston 101 is in a retractable state, and the contact position between its non-tooth end and the working surface 211 changes, eliminating the movement transmitted from the engine cam 230 to the valve 300.

[0066] When it is necessary to restore the valve movement of the engine, such as Figure 2 , the control valve (not shown) disconnects the oil discharge, the driving piston 113 resets, driving the rotating gear ring 112 to rotate and reset, aligning the tooth tip of the rotating gear ring 112 with the tooth tip of the tooth-shaped transmission piston 101, and the transmission piston 101 extends (cannot retract), so that the rear rocker arm 210 and the front rocker arm 10 are locked at Figure 2 position. The movement of the engine cam 230 is transmitted to the engine valve 300 through the roller 235, the rear rocker arm 210, the transmission mechanism 100, the front rocker arm 10, the elephant foot mechanism 50, and the valve bridge 400. There is a stop mechanism between the front rocker arm 10 and the rear rocker arm 210, including the stop protrusions 213 and 214 on the front rocker arm 10.

[0067] It can be found from the operation process of this embodiment that at different rotation positions of the rotating gear ring 112, the force application positions where the working surface (end face) 211 of the rear rocker arm 210 interacts with the transmission mechanism 100 on the front rocker arm 10 are different. The movement of the working surface (end face) 211 of the rear rocker arm 210 in its normal direction (the same as the movement direction of the tooth-shaped transmission piston 101) is less than the movement in its tangential direction (perpendicular to the movement direction of the transmission piston 101). This means that a smaller stroke of the transmission piston 101 can absorb a larger lift of the engine cam 230, making the rocker arm mechanism for variable valve drive of the present invention more compact.

[0068] It should be noted that the situation where the movement of the working surface 211 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.

[0069] In one example, the front rocker arm shaft 205 and the rear rocker arm shaft 120 are arranged in parallel.

[0070] In one example, the other end of the front rocker arm 10 and the rear rocker arm 210 may or may not be connected. In the embodiment, one end of the front rocker arm 10 and one end of the rear rocker arm 210 are rotatably connected to the rear rocker arm shaft 120.

[0071] Such as Figure 3 ,Figure 4 As shown, the transmission mechanism 100 includes a linkage mechanism and a transmission piston 101. The linkage mechanism includes a connecting rod 111 and a connecting rod 112. One end of the connecting rod 111 is connected to the transmission piston 101. The end face of the transmission piston 101 is in contact connection with the working surface 211 of the rear rocker arm 210. The engine oil is supplied to the transmission mechanism through an oil passage, pushing the driving piston 113 to move and driving the linkage mechanism to expand and contract. The expansion and contraction of the linkage mechanism drives the transmission piston 101 to move, causing the contact position between the transmission piston 101 and the working surface 211 to change.

[0072] The operation process is as follows. As shown in the appendix Figure 4 For the transmission mechanism 100 shown, when cylinder deactivation (eliminating the normal valve movement of the engine) is required, the cylinder deactivation control valve (not shown) opens to supply oil. The engine oil is supplied to the transmission mechanism through the oil passage, causing the rocker one 111 and the rocker two 112 to bend, so that the transmission piston 101 is in a retractable state. The working surface 211 pushes the transmission piston 101 from the extended position to the retracted position, and the front rocker arm 10 and the rear rocker arm 210 are in a disconnected state, eliminating the movement transmitted from the cam 230 to the valve 300.

[0073] When the normal valve movement of the engine needs to be restored, as shown in Figure 3 , the cylinder deactivation control valve (not shown) disconnects to drain oil. Under the action of the return spring 107, the rocker one 111 and the rocker two 112 are straightened, and the transmission piston 101 is pushed outwards (to the right) and locked, so that the rear rocker arm 210 is locked with the front rocker arm 10 at the Figure 3 position. The movement of the engine cam 230 is transmitted to the engine valve 300 through the roller 235, the rear rocker arm 210, the transmission mechanism 100, the front rocker arm 10, the elephant foot mechanism 50, and the valve bridge 400. There is a stop mechanism between the front rocker arm 10 and the rear rocker arm 210, including the stop bosses 213 and 214 on the front rocker arm 10.

[0074] In one example, the working surface is in contact connection with the transmission piston and is designed as a predetermined profile surface that causes the transmission piston to generate a definite lift. The predetermined profile surface can be any one of a positive curvature, a negative curvature, and a plane.

[0075] In one example, the contact connection between the working surface and the transmission piston is such that when the rocker arm where the working surface is located rotates, it can push the transmission piston to generate a definite lift profile surface. The surface can be a positive curvature or a negative curvature surface.

[0076] In one example, the working surface of the transmission piston can also be a positive curvature, a negative curvature, or a plane.

[0077] In one example, through the transmission between the working surface and the transmission piston, the movement can be reduced or amplified.

[0078] In one example, through the design of the predetermined profile of the working surface, the required contact point curvature and the follower piston speed element can be set at each point of the motion process.

[0079] This embodiment further includes an anti - fly - off spring 212 disposed on the rear rocker arm 210. As Figure 1 、 2 、3, and 4 show, the anti - fly - off spring 212 pushes the rear rocker arm 210 towards the cam 230 of the engine, preventing impact when the rear rocker arm 210 moves. This anti - fly - off spring can also be installed in other positions.

[0080] The stop mechanism in the embodiment is used to limit the relative rotation of the front rocker arm and the rear rocker arm on the shaft. As Figure 1 、 Figure 2 shown, the stop mechanism includes a boss 213 and a boss 214. The boss 213 is used for stopping when the rear rocker arm 210 rotates clockwise, and the boss 214 is used for stopping when the rear rocker arm 210 has an idle stroke (rotates counter - clockwise).

[0081] As Figure 5 shown, a built - in spring 106 of the transmission mechanism can also be used to replace the anti - fly - off spring 212 in the above Figure 1 、 2 、3, and 4. By pushing the built - in spring 106 through the transmission piston 101 towards the working surface of the rear rocker arm, the roller 235 of the rear rocker arm is pressed against the cam 230 to prevent fly - off. One end of the transmission piston 101 is connected to the built - in spring 106, and the other end of the transmission piston 101 abuts against the working surface 211. The built - in spring 106 is disposed in the accommodation cavity; the accommodation cavity is filled with engine oil so that the transmission piston 101 is stopped. When the transmission piston 101 is in the locked position and stopped, the front rocker arm 10 and the rear rocker arm 210 are in a mutually locked state; when the accommodation cavity is not filled with engine oil, the transmission piston 101 moves between the locked position and the unlocked position, and the front rocker arm 10 and the rear rocker arm 210 are in a disconnected state.

[0082] Note that the above description applies equally to the actuation of the exhaust valves, intake valves, and brake valves of the engine.

[0083] The above description includes many different specific embodiments, which should not be regarded as limiting the scope of the present invention, but rather as representing some specific exemplifications of the present invention, from which many other variations are possible. For example, the engine braking method or system 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 braking cam can all be changed.

[0084] In addition, the types of the brake rocker arm mechanism can also be diverse. Besides the split-type (front and rear rocker arms) rocker arm of the present application, it can also be an integral hydraulic special brake rocker arm, a fixed chain-type brake rocker arm, etc.

[0085] The embodiment also provides an engine, including the above-mentioned rocker arm mechanism.

[0086] The embodiment also provides a vehicle, including the above-mentioned engine.

[0087] References throughout the specification to "an example", "an embodiment", or "one embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of "an example", "in an embodiment", or "in one embodiment" throughout the specification are not necessarily all referring to the same embodiment. Additionally, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0088] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A rocker arm mechanism for an engine variable valve drive, characterized in that: The rocker arm mechanism includes: a front rocker arm, a rear rocker arm, and a transmission mechanism. One end of the front rocker arm is close to the engine valve, and one end of the rear rocker arm is close to the engine cam. Among them, the transmission mechanism is arranged at the other end of the front rocker arm, and a working surface is provided at the other end of the rear rocker arm; or, the transmission mechanism is arranged at the other end of the rear rocker arm, and a working surface is provided at the other end of the front rocker arm; the change in the force application position where the transmission mechanism in one of the front rocker arm or the rear rocker arm interacts with the working surface of the other rocker arm causes the front rocker arm and the rear rocker arm to be in a mutually locked state or a disconnected state, so as to change the motion transmitted from the engine cam to the engine valve.

2. The rocker arm mechanism according to claim 1, wherein: It further includes an anti-jump spring, and the anti-jump spring pushes the rocker arm including the working surface towards the cam or the valve side.

3. The rocker arm mechanism according to claim 1, characterized in that: The transmission mechanism and the working surface satisfy one or more of the following conditions: (1) The change in the force application position where the working surface interacts with the transmission mechanism changes the relative positions of the front rocker arm and the rear rocker arm and the motion transmitted from the engine cam to the engine valve; (2) The motion of the working surface in its normal direction is less than the motion in its tangential direction.

4. The rocker arm mechanism according to claim 1, wherein: The rocker arm mechanism further includes a front rocker arm shaft and a rear rocker arm shaft, where when the front rocker arm and the rear rocker arm are in the mutually locked state, the rear rocker arm cannot rotate relative to the front rocker arm, and the front rocker arm and the rear rocker arm rotate as a whole around the front rocker arm shaft, and the motion of the engine cam is transmitted to the engine valve; when the front rocker arm and the rear rocker arm are in the disconnected state, the rear rocker arm can rotate relative to the front rocker arm, the rear rocker arm rotates around the rear rocker arm shaft, and at least part of the motion of the engine cam is not transmitted to the engine valve.

5. The rocker arm mechanism according to claim 1, characterized in that: The transmission mechanism includes a movable transmission piston, one end of the transmission piston abuts against the working surface, and when the transmission piston is in different positions, the force application position where one end of the transmission piston interacts with the working surface changes.

6. The rocker arm mechanism according to claim 5, wherein: The positions of the movable transmission piston include a locked position and a non-locked position, where when the front rocker arm and the rear rocker arm are in the mutually locked state, the transmission piston is in the locked position and is stopped; when the front rocker arm and the rear rocker arm are in the disconnected state, the transmission piston moves between the locked position and the non-locked position.

7. The rocker arm mechanism according to claim 5, characterized in that: The transmission mechanism further includes a rotating gear ring, the rotating gear ring includes a tooth end, the transmission piston includes a tooth end and a non-tooth end, the tooth end of the rotating gear ring is movably connected to the tooth end of the transmission piston, the non-tooth end of the transmission piston abuts against the working surface, the rotation of the rotating gear ring causes a change in the relative position of the tooth end of the rotating gear ring and the tooth end of the transmission piston, the contact position of the non-tooth end of the transmission piston with the working surface changes, and the motion transmitted from the engine cam to the engine valve is changed.

8. The rocker arm mechanism according to claim 7, characterized in that: The tooth crest of the tooth end of the transmission piston is aligned with the tooth crest of the tooth end of the rotating gear ring so that the transmission piston is stopped. When the transmission piston is in the locked position and stopped, the front rocker arm and the rear rocker arm are in the mutually locked state; the tooth crest of the tooth end of the transmission piston is aligned with the tooth valley of the tooth end of the rotating gear ring, the transmission piston moves between the locked position and the unlocked position, and the front rocker arm and the rear rocker arm are in the disconnected state.

9. The rocker arm mechanism according to claim 5, characterized in that: The transmission mechanism further includes a link mechanism. One end of the transmission piston is connected to the link mechanism, and the other end of the transmission piston abuts against the working surface. The telescopic movement of the link mechanism drives the transmission piston to move, so that the contact position between the transmission piston and the working surface changes, and the movement transmitted from the engine cam to the valve is changed.

10. The rocker arm mechanism according to claim 9, characterized in that: The two links of the link mechanism are in a straight line so that the transmission piston is stopped. When the transmission piston is in the locked position and stopped, the front rocker arm and the rear rocker arm are in the mutually locked state; the two links of the link mechanism are bent, the transmission piston moves between the locked position and the unlocked position, and the front rocker arm and the rear rocker arm are in the disconnected state.

11. The rocker arm mechanism according to claim 5, characterized in that: The transmission mechanism further includes a built-in spring. One end of the transmission piston is connected to the built-in spring, and the other end of the transmission piston abuts against the working surface. The built-in spring is arranged in a receiving cavity; the receiving cavity is filled with engine oil so that the transmission piston is stopped. When the transmission piston is in the locked position and stopped, the front rocker arm and the rear rocker arm are in the mutually locked state; the receiving cavity is not filled with engine oil, the transmission piston moves between the locked position and the unlocked position, and the front rocker arm and the rear rocker arm are in the disconnected state.

12. The rocker arm mechanism according to claim 5, characterized in that: The working surface is in contact connection with the transmission piston and is designed as a predetermined contour surface, and the predetermined contour surface can be any one of a positive curvature, a negative curvature and a plane.

13. The rocker arm mechanism according to claim 12, characterized in that: The working surface of the toothed transmission piston can be any one of a positive curvature, a negative curvature and a plane.

14. The rocker arm mechanism according to claim 12, characterized in that: Through the design of the predetermined contour of the working surface, the required contact point curvature and the follower piston speed elements can be set at each point during the movement process.

15. The rocker arm mechanism according to claim 1, characterized in that: The rocker arm mechanism further includes a stop mechanism arranged on the front rocker arm or the rear rocker arm, and the stop mechanism is used to limit the relative rotation of the front rocker arm and the rear rocker arm on the shaft.

16. The rocker arm mechanism according to claim 1, wherein: The rocker arm mechanism further includes an anti-flying-off spring, and the anti-flying-off spring pushes the rear rocker arm towards the engine cam.

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