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 invention relates to the field of engine valve driving, in particular to a rocker arm mechanism used for variable engine valve driving. 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 present invention provides a rocker arm mechanism for variable valve drive of an engine, which solves the technical problems in the prior art of complex valve drive structure and control, poor reliability and durability of hydraulic drive to open the valve, and limited application.

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

[0009] In a first aspect of the present invention, a rocker arm mechanism for variable valve driving of an engine is provided, the rocker arm mechanism comprising: 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, one end of the rear rocker arm is close to the engine cam, wherein:

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

[0011] The force position change of the transmission mechanism in one of the front rocker arms or the rear rocker arms interacting with the working surface of the other rocker arm causes the front rocker arm and the rear rocker arm to be locked or disconnected with each other, so as to change the movement transmitted by the engine cam to the engine valve.

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

[0013] Optionally, an anti-jump spring is also included, which pushes the rocker arm including the working curved surface toward the cam or valve side.

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

[0015] (1) The force position of the interaction between the working curved surface and the transmission mechanism changes, thereby changing the relative position of the front rocker arm and the rear rocker arm and the movement transmitted from the engine cam to the engine valve;

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

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

[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, the front rocker arm and the rear rocker arm rotate as a whole around the front rocker arm shaft, and the movement 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 axis, 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 which abuts against the working curved surface, and when the transmission piston is in different positions, the force position where the one end of the transmission piston interacts with the working curved surface changes.

[0021] Optionally, the position of the movable transmission piston includes a locking position and an unlocking position, wherein

[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 also includes a rotating ring gear, which includes a tooth end, and the transmission piston includes a tooth end and a non-tooth end. The tooth end of the rotating ring gear is movably connected to the tooth end of the transmission piston, and the non-tooth end of the transmission piston abuts against the working curved surface. The rotation of the rotating ring gear causes the relative position of the tooth end of the rotating ring gear and the tooth end of the transmission piston to change, and the contact position of the non-tooth end of the transmission piston with the working curved surface changes, so that the movement transmitted to the engine valve by the engine cam 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 ring gear 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 ring gear, 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 also includes a connecting rod mechanism, one end of the transmission piston is connected to the connecting rod mechanism, and the other end of the transmission piston abuts against the working curved surface. The connecting rod mechanism extends and retracts to drive the transmission piston to move, so that the contact position between the transmission piston and the working curved surface changes, and the movement transmitted to the valve by the engine cam is changed.

[0027] Optionally, the two connecting rods of the connecting rod mechanism are in the same straight line so that the transmission piston is stopped, and 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 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 also 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 curved surface, and the built-in spring is arranged in a accommodating chamber; the accommodating chamber is filled with engine oil to stop the transmission piston, and 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 accommodating chamber 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 curved surface is in contact with the transmission piston and is designed as a curved surface with a predetermined contour, and the curved surface with a predetermined contour 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, by designing a predetermined contour of the working surface, the required contact point curvature and the follow-up piston speed element can be set at each point in the movement process.

[0032] Optionally, 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 mutual rotation of the front rocker arm and the rear rocker arm on the axis.

[0033] According to a second aspect of the present invention, there is provided a rocker arm mechanism for variable valve drive of an engine, comprising: a front rocker arm rotating around a front rocker arm shaft and a rear rocker arm rotating relative to the front rocker arm, wherein one end of the front rocker arm is close to the valve of the engine, and the rear rocker arm is rotatably connected to the 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 position of the working surface interacting with the transmission mechanism changes, thereby changing the relative position of the front rocker arm and the rear rocker arm and the movement transmitted to the engine valve by the engine cam, and (2) the movement of the working surface in its normal direction is smaller than the movement in its tangential direction.

[0034] According to a third aspect of the present invention, a rocker arm mechanism for variable valve drive of an engine is provided, comprising: a front rocker arm, a rear rocker arm and a transmission mechanism, wherein the transmission mechanism is arranged in 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, and the other end of the front rocker arm or the rear rocker arm has a working curved surface, and the force position change of the transmission mechanism in one rocker arm interacting with the working curved surface of the other rocker arm makes the front rocker arm and the rear rocker arm in a mutually locked or disconnected state, thereby changing the movement transmitted to the engine valve by the engine cam.

[0035] Furthermore, the second and third aspects of the present invention provide a rocker arm mechanism, wherein the transmission mechanism includes a toothed transmission piston and a rotating ring gear, the tooth end of the rotating ring gear is connected to the tooth end of the toothed transmission piston, and the other end of the toothed transmission piston is contacted and connected to the working curved surface, and the rotation of the rotating ring gear causes the relative position of the tooth end of the rotating ring gear and the tooth end of the toothed transmission piston to change, the contact position of the toothed transmission piston with the working curved surface changes, and the movement transmitted to the valve by the engine cam is changed.

[0036] Further, in the rocker arm mechanism provided in the second aspect and the third aspect of the present invention, the working curved surface is in contact with the toothed transmission piston and is designed as a predetermined contour curved surface, and the predetermined contour curved surface is any one of a positive curvature, a negative curvature and a plane;

[0037] Furthermore, in the rocker arm mechanism provided in the second aspect and the third aspect of the present invention, the working surface of the toothed transmission piston may also be a positive curvature or a negative curvature, as well as a plane;

[0038] Furthermore, in the rocker arm mechanism provided in the second and third aspects of the present invention, the required contact point curvature and follow-up piston speed element can be set at each point in the motion process through the predetermined contour design of the working surface.

[0039] Furthermore, the second and third aspects of the present invention provide a rocker arm mechanism, wherein the transmission mechanism also includes a connecting rod mechanism and a transmission piston, one end of the connecting rod mechanism is connected to the transmission piston, the end face of the transmission piston is in contact with the working curved surface of the rocker arm, and the connecting rod mechanism is extended and retracted to drive the transmission piston to move, so that the contact position between the transmission piston and the working curved surface changes.

[0040] Furthermore, in the rocker arm mechanism provided in the second aspect and the third aspect of the present invention, the transmission mechanism has a piston chamber and a driving unit, and the driving unit is used to drive the transmission piston to move in the piston chamber.

[0041] Furthermore, in the rocker arm mechanism provided in the second aspect and the third aspect of the present invention, the driving unit includes a hydraulic control valve for controlling the movement of the transmission piston.

[0042] Furthermore, the rocker arm mechanism provided in the second aspect and the third aspect of the present invention further includes an anti-fly-off spring, and the anti-fly-off spring pushes the rear rocker arm toward the cam of the engine.

[0043] Furthermore, the rocker arm mechanism provided in the second aspect and the third aspect of the present invention further includes an anti-bounce spring, which pushes the rocker arm including the working curved surface toward the cam or valve side.

[0044] Furthermore, the rocker arm mechanism provided in the second aspect and the third aspect of the present invention further includes a stop mechanism, and the stop mechanism is used to limit the mutual rotation of the front rocker arm and the rear rocker arm on the axis.

[0045] A fourth aspect of the present invention provides an engine, which includes the rocker arm mechanism provided by the first aspect, the second aspect, and the third aspect of the present invention.

[0046] A fifth aspect of the present invention provides an automobile comprising the above-mentioned engine.

[0047] Beneficial effects of the present invention:

[0048] Compared with the prior art, the present invention has a positive and obvious effect. The rocker arm mechanism of the present invention includes a toothed transmission piston and a rotating gear ring. The rotation of the rotating gear ring causes the relative position of the tooth end of the rotating gear ring and the tooth end of the toothed transmission piston to change, and the contact position of the toothed transmission piston with the working curved surface changes, thereby generating or losing the valve movement of the engine, and realizing the conversion between engine ignition and engine cylinder stop or braking, etc. The present invention has the advantages of simple and reliable structure, easy manufacturing and assembly, and wide application. In particular, the structure is simple and reliable, and can be applied to variable valve drive of engines with large lift, including engine cylinder stop and large stroke engine braking that cancel the entire valve lift, as well as applications in scenarios with narrow installation space.

[0049] In addition, the rocker arm mechanism of the present invention is composed of front and rear rocker arms. Through the conversion of the working curved surface and the transmission piston, the front and rear rocker arms are connected or separated, the valve movement of the engine is generated or lost, and the conversion between engine ignition and engine cylinder stop or braking is realized. Through the design of the shape of the working curved surface, the transmission piston can achieve a larger idle stroke (lost motion) with a smaller stroke. Therefore, it has the advantages of simple and reliable structure, easy manufacturing and assembly, and wide application. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0054] Figure 5 It is a schematic diagram of a transmission mechanism with an anti-jump spring in one embodiment of the rocker arm mechanism of the present invention. DETAILED DESCRIPTION

[0055] 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.

[0056] 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, so that people familiar with this technology can understand and read them, and are not used to limit the limiting conditions that the present invention can implement, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", "front", "back", etc. quoted in this specification are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the embodiments of the present application. 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.

[0057] 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.

[0058] Example

[0059] In one example, a rocker arm mechanism for variable valve drive of an engine is provided, comprising: 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 being close to the engine valve, the rear rocker arm being rotatably connected to the rear rocker arm shaft, one end of the rear rocker arm being close to the engine cam, and the other end having a working curved surface and close to a transmission mechanism on the front rocker arm, the engine cam driving the rear rocker arm to rotate around the rear rocker arm shaft, the working curved surface of the rear rocker arm acting on the transmission mechanism on the front rocker arm, and having the following characteristics: (1) the force position of the working curved surface interacting with the transmission mechanism changes, thereby changing the rotation of the front rocker arm and the movement transmitted to the engine valve by the engine cam, and (2) the movement of the working curved surface in its normal direction is smaller than the movement in its tangential direction.

[0060] In one example, a rocker arm mechanism for variable valve drive of an engine is provided, comprising: a front rocker arm, a rear rocker arm and a transmission mechanism, wherein the transmission mechanism is arranged in 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, and the other end of the front rocker arm or the rear rocker arm has a working curved surface, and the force position change of the transmission mechanism in one rocker arm interacting with the working curved 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 movement transmitted to the engine valve by the engine cam.

[0061] It should be noted that: when the front rocker arm and the rear rocker arm are in a mutually locked state, the rear rocker arm cannot rotate relative to the front rocker arm, the front rocker arm and the rear rocker arm rotate as a whole around the front rocker arm shaft, and the movement of the engine cam is transmitted to the engine valve to increase or completely restore the movement of the engine valve; when the front rocker arm and the rear rocker arm are in a 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, resulting in partial or complete loss of the engine valve stroke.

[0062] Reference Figures 1 to 5 The transmission mechanism 100 includes a movable transmission piston 101, one end of which abuts against the working curved surface 211. When the transmission piston 101 is in different positions, the force position of the interaction between the one end of the transmission piston 101 and the working curved surface 211 changes. The position of the movable transmission piston 101 includes a locking position ( Figure 2 , Figure 3 or Figure 5 position) and unlocked position ( Figure 1 and or Figure 4The transmission piston 101 is in the locked position and is stopped when the front rocker arm 10 and the rear rocker arm 210 are in a mutually locked state; when the front rocker arm 10 and the rear rocker arm 210 are in a disconnected state, the transmission piston 101 moves between the locked position and the unlocked position.

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

[0064] The tooth peaks of the tooth ends of the transmission piston 101 are aligned with the tooth peaks of the tooth ends of the rotating ring gear 112 to stop the transmission piston 101. When the transmission piston 101 is in the locked position and is stopped, the front rocker arm 10 and the rear rocker arm 210 are in a mutually locked state; the tooth peaks of the tooth ends of the transmission piston 101 are aligned with the tooth valleys of the tooth ends of the rotating ring gear 112, 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.

[0065] The operation process is as follows. Figure 1 The transmission mechanism 100 shown in the figure, when it is necessary to eliminate the valve movement of the engine (cylinder deactivation), the control valve (not shown) is opened to supply oil, and the engine oil is supplied to the transmission mechanism 100 through the oil circuit, pushing the drive piston 113, and the drive piston 113 pushes the rotating ring gear 112 to rotate, so that the relative position of the tooth end of the rotating ring gear 112 and the tooth end of the toothed transmission piston 101 changes (for example, switching from tooth top to tooth top to tooth top to tooth top to tooth valley), and the toothed transmission piston 101 is in a retractable state, and the contact position of its non-tooth end with the working curved surface 211 changes, thereby eliminating the movement of the engine cam 230 transmitted to the valve 300.

[0066] When it is necessary to restore the engine's valve movement, such as Figure 2 , the control valve (not shown) is disconnected to unload the oil, the driving piston 113 is reset, and the rotating ring gear 112 is driven to rotate and reset, so that the top of its tooth and the top of the tooth of the gear transmission piston 101 are aligned, and the transmission piston 101 is extended (cannot be retracted), so that the rear rocker arm 210 is locked with the front rocker arm 10 Figure 2The 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 stop bosses 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 working curved surface (end surface) 211 of the rear rocker arm 210 and the force position of the transmission mechanism 100 on the front rocker arm 10 are different, and the working curved surface (end surface) 211 of the rear rocker arm 210 in its normal movement (same as the movement direction of the toothed transmission piston 101) is smaller than its tangential movement (perpendicular to the movement direction of the transmission piston 101). This means that the smaller stroke of the transmission piston 101 can absorb the larger lift of the engine cam 230, making the rocker arm mechanism of the engine variable valve drive of the present invention more compact.

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

[0069] In one example, the front swingarm shaft 205 and the rear swingarm 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 be connected or not 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] like Figure 3 , Figure 4 As shown, the transmission mechanism 100 includes a connecting rod mechanism and a transmission piston 101. The connecting rod 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 with and connected to the working curved surface 211 of the rear rocker arm 210. The engine oil is supplied to the transmission mechanism through the oil circuit, pushing the drive piston 113 to move and drive the connecting rod mechanism to extend and retract. The extension and retraction of the connecting rod mechanism drives the transmission piston 101 to move, so that the contact position of the transmission piston 101 and the working curved surface 211 changes.

[0072] The operation process is as follows. Figure 4When the transmission mechanism 100 shown in the figure needs to stop the cylinder (eliminating the normal valve movement of the engine), the cylinder stop control valve (not shown) is opened to supply oil, and the engine oil is supplied to the transmission mechanism through the oil circuit, so that the rocker arm 111 and the rocker arm 2 112 are bent, so that the transmission piston 101 is in a retractable state, and 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 to the valve 300 by the cam 230.

[0073] When it is necessary to restore the normal valve movement of the engine, such as Figure 3 The cylinder deactivation control valve (not shown) is disconnected to unload the oil, and the return spring 107 acts to make the rocker arm 111 and the rocker arm 2 112 straighten, so that the transmission piston 101 is pushed outward (right) and locked, so that the rear rocker arm 210 is locked with the front rocker arm 10 Figure 3 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 stop bosses 213 and 214 on the front rocker arm 10.

[0074] In one example, the working curved surface is in contact with the transmission piston and is designed to enable the transmission piston to generate a predetermined contour curved surface with a certain lift, wherein the predetermined contour curved surface is any one of a positive curvature, a negative curvature and a plane.

[0075] In one example, the working curved surface is in contact with the transmission piston. When the rocker arm on which the working curved surface is located rotates, it can push the transmission piston to generate a profile curved surface with a certain lift. The curved surface can be a positive curvature or a negative curvature surface.

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

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

[0078] In one example, by designing a predetermined contour of the working surface, the required contact point curvature and the follow-up piston speed element can be set at each point in the motion process.

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

[0080] The stop mechanism in the embodiment is used to limit the mutual rotation of the front rocker arm and the rear rocker arm on the axis. Figure 1 , Figure 2 As shown, the stop mechanism includes a protrusion 213 and a protrusion 214. The protrusion 213 is used to stop the rear rocker arm 210 when it rotates clockwise, and the protrusion 214 is used to stop the rear rocker arm 210 when it has an idle stroke (rotates counterclockwise).

[0081] like Figure 5 As shown, a transmission mechanism built-in spring 106 can also be used to replace the above Figure 1 , 2 The anti-fly-off spring 212 in 3 and 4 is pushed toward the working curved surface of the rear rocker arm through the transmission piston 101, thereby pressing the roller 235 of the rear rocker arm onto the cam 230 to prevent it from flying 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 is in contact with the working curved surface 211. The built-in spring 106 is arranged in the accommodating chamber; the accommodating chamber is filled with engine oil so that the transmission piston 101 is stopped. When the transmission piston 101 is in the locked position and is stopped, the front rocker arm 10 and the rear rocker arm 210 are in a mutually locked state; when the accommodating chamber 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 is applicable to the actuation of the exhaust valve, intake valve and brake valve of the engine at the same time.

[0083] 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 braking method or system shown here can be used not only for overhead cam engines, but also for pushrod / push tube engines; not only for opening single valves, but also for opening double valves; not only for driving exhaust valves, but also for driving intake valves; the number, size, shape and phase of the bosses contained in the brake cam can be changed.

[0084] In addition, there are many types of brake rocker arm mechanisms. In addition to the split (front and rear 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.

[0085] The embodiment further provides an engine, comprising the rocker arm mechanism described above.

[0086] The embodiment further provides a car, comprising the above-mentioned engine.

[0087] 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.

[0088] 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 rocker arm mechanism for variable valve drive of an engine, characterized in that: The rocker arm mechanism comprises: 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, wherein: The transmission mechanism is arranged at the other end of the front rocker arm, and the other end of the rear rocker arm is provided with a working curved surface; or, The transmission mechanism is arranged at the other end of the rear rocker arm, and the other end of the front rocker arm is provided with a working curved surface; The force position change of the transmission mechanism in one of the front rocker arms or the rear rocker arms interacting with the working surface of the other rocker arm causes the front rocker arm and the rear rocker arm to be locked or disconnected with each other, so as to change the movement transmitted by the engine cam to the engine valve. Optionally, the rocker arm mechanism further includes an anti-fly-off spring, and the anti-fly-off spring pushes the rear rocker arm toward the cam of the engine. Optionally, an anti-jump spring is also included, which pushes the rocker arm including the working curved surface toward the cam or valve side.

2. The rocker arm mechanism according to claim 1, characterized in that: The transmission mechanism and the working curved surface meet one or more of the following conditions: (1) The force position of the interaction between the working curved surface and the transmission mechanism changes, thereby changing the relative position of the front rocker arm and the rear 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 smaller than the movement in its tangential direction.

3. The rocker arm mechanism according to claim 1, characterized in that: The rocker arm mechanism also includes a front rocker arm shaft and a rear rocker arm shaft, wherein 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, the front rocker arm and the rear rocker arm rotate as a whole around the front rocker arm shaft, and the movement 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 axis, and the movement of the engine cam is at least partially not transmitted to the engine valve.

4. The rocker arm mechanism according to claim 1, characterized in that: The transmission mechanism comprises a movable transmission piston, one end of which abuts against the working curved surface. When the transmission piston is in different positions, the force position where the one end of the transmission piston interacts with the working curved surface changes.

5. The rocker arm mechanism according to claim 4, characterized in that: The movable position of the transmission piston includes a locked position and an unlocked position, wherein 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 unlocked position.

6. The rocker arm mechanism according to claim 4, characterized in that: The transmission mechanism also includes a rotating ring gear, which includes a tooth end, and the transmission piston includes a tooth end and a non-tooth end. The tooth end of the rotating ring gear is movably connected to the tooth end of the transmission piston, and the non-tooth end of the transmission piston abuts against the working curved surface. The rotation of the rotating ring gear causes the relative position of the tooth end of the rotating ring gear and the tooth end of the transmission piston to change, and the contact position of the non-tooth end of the transmission piston with the working curved surface changes, so that the movement transmitted to the engine valve by the engine cam is changed. 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 ring gear 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 ring gear, 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.

7. The rocker arm mechanism according to claim 4, characterized in that: The transmission mechanism also includes a connecting rod mechanism, one end of the transmission piston is connected to the connecting rod mechanism, and the other end of the transmission piston abuts against the working curved surface. The connecting rod mechanism is extended and retracted to drive the transmission piston to move, so that the contact position between the transmission piston and the working curved surface changes, and the movement transmitted to the valve by the engine cam is changed. Optionally, the two connecting rods of the connecting rod mechanism are in the same straight line so that the transmission piston is stopped, and 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 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.

8. The rocker arm mechanism according to claim 4, characterized in that: The transmission mechanism also 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 curved surface, and the built-in spring is arranged in a accommodating chamber; the accommodating chamber is filled with engine oil to stop the transmission piston, and 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 accommodating chamber 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.

9. The rocker arm mechanism according to claim 4, characterized in that: The working curved surface is in contact with the transmission piston and is designed as a predetermined contour curved surface, wherein the predetermined contour curved surface is any one of a positive curvature, a negative curvature and a plane; Preferably, the working surface of the toothed transmission piston is any one of a positive curvature, a negative curvature and a plane; Preferably, by designing a predetermined contour of the working surface, the required contact point curvature and the follow-up piston speed element can be set at each point in the movement process.

10. The rocker arm mechanism according to claim 1, characterized in that: The rocker arm mechanism also includes a stop mechanism arranged on the front rocker arm or the rear rocker arm, and the stop mechanism is used to limit the mutual rotation of the front rocker arm and the rear rocker arm on the axis.

Images