A rocker arm mechanism with variable lift without impact and its connection structure

Abstract

The present invention discloses a rocker mechanism with variable lift without impact and its connection structure, including a rocker shaft and a rocker connected to the rocker shaft, a movable sleeve on the rocker shaft connected to an eccentric ring, a movable sleeve of the rocker connected to the eccentric ring, a piston structure which can fix the rocker and the eccentric ring as one or fix the eccentric ring and the rocker shaft as one is arranged in the structure composed of the rocker, the eccentric ring and the rocker shaft along the radial direction of the rocker shaft, one end of the piston structure is arranged in the rocker shaft, and the other end passes through the eccentric ring and is arranged in the rocker, and an oil injection channel for injecting oil into the piston structure is opened in the rocker shaft. The present invention adjusts the rotation center of the rocker through the piston structure, and can increase the valve lift by increasing the rocker ratio. The eccentric amount and the direction of the eccentricity can be adjusted according to actual needs and the needs of space layout to meet the needs of different engines.

Description

Technical Field

[0001] The invention relates to the technical field of engine valve distribution structure, in particular to a rocker arm mechanism with variable lift without impact and a connecting structure thereof. Background Art

[0002] In the current engine valve train, due to the consideration of the thermal expansion deformation of the valve train parts and the deformation of the parts under stress, the valve train needs to set appropriate valve clearance after assembly, and the existence of valve clearance will cause impact when the valve is opened and closed. Therefore, the cam profile needs to be designed with a buffer section at the opening and closing time to reduce the speed of the valve when opening and seating to the allowable range, thereby reducing the impact. The height of the buffer section (converted to the valve side) should be greater than the valve clearance to play a buffering role.

[0003] A braking rocker arm and an engine are disclosed in the comparative document 1 with application number 202110274216.7 and titled "A Braking Rocker Arm and Engine". A braking rocker arm comprises: a rocker arm, on which a guide groove is provided; a brake piston, which is slidably arranged in the guide groove, and the brake piston has a first position and a second position relative to the rocker arm, when the brake piston is in the first position, the brake piston is separated from the valve, and when the brake piston is in the second position, the brake piston opens the valve; a thermal deformation driving member installed on the rocker arm, the thermal deformation driving member is transmission-connected with the brake piston, and is used to drive the brake piston to switch from the first position to the second position; an elastic member, one end of the elastic member is connected to the brake piston, and the other end is connected to the rocker arm, and is used to drive the brake piston to switch from the second position to the first position.

[0004] The comparative document 2 with application number 202010941905.4 and titled "A rocker mechanism and engine assembly" discloses a rocker mechanism and an engine assembly, which includes a rocker shaft, a rocker arm, a valve clearance adjustment device, a valve mechanism and a control valve. The rocker arm is rotatably arranged on the rocker shaft, the valve mechanism includes a valve bridge, the rocker arm is provided with a plunger cavity, the valve clearance adjustment device includes a hydraulic tappet slidably arranged in the plunger cavity, the plunger cavity is supplied with oil through an oil supply oil circuit, and the control valve can open or close the oil supply oil circuit. When the control valve opens the oil supply oil circuit, the hydraulic tappet can abut against the valve bridge and eliminate the gap between the valve bridge and the hydraulic tappet.

[0005] It can be seen from the above-mentioned comparative documents 1 and 2 that the existing variable lift rocker arm mechanisms all achieve the change of valve lift by changing the valve clearance (or equivalent to changing the valve clearance). Such a design will inevitably lead to the situation where the valve clearance is greater than the height of the cam buffer section. At this time, the opening and seating of the valve will have a violent impact, produce abnormal noise, and have a great impact on the reliability of the valve mechanism parts, especially aggravating the wear between the valve and the valve seat. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and to provide a rocker arm mechanism and its connecting structure which can change the rocker arm lift by shifting the rocker arm rotation center and will not produce impact on the opening and seating of the valve.

[0007] To achieve this object, the impact-free variable-lift rocker mechanism designed in the present invention includes a rocker shaft and a rocker arm connected to the rocker shaft, a movable sleeve on the rocker shaft is connected to an eccentric ring, and the rocker movable sleeve is connected to the eccentric ring. A piston structure that can fix the rocker arm and the eccentric ring as a whole or fix the eccentric ring and the rocker shaft as a whole is arranged in the structure composed of the rocker arm, the eccentric ring and the rocker shaft and along the radial direction of the rocker shaft, one end of the piston structure is arranged in the rocker shaft, and the other end passes through the eccentric ring and is arranged in the rocker arm, and an oil injection channel is opened in the rocker shaft for injecting oil into the piston structure.

[0008] Furthermore, the piston structure includes a piston cavity arranged along the radial direction of the rocker arm shaft, and the piston cavity is provided with a plunger that can move axially along the piston cavity and an elastic structure for pushing one end of the plunger.

[0009] Furthermore, the piston cavity includes a first piston cavity, a second piston cavity and a third piston cavity which are respectively fixed in the rocker shaft, the eccentric ring and the rocker arm, the elastic structure is arranged in the third piston cavity, and the oil injection channel is connected to the first piston cavity.

[0010] Furthermore, the original length of the elastic structure is the same as the length of the third piston cavity, and the length of the plunger is greater than the length of the second piston cavity and less than the sum of the length of the second piston cavity and the length of the third piston cavity.

[0011] Furthermore, the elastic structure includes an elastic member arranged along the axial direction of the third piston cavity, one end of the elastic member is fixed in the third piston cavity, and the other end is fixed to the thrust member.

[0012] Furthermore, the elastic member includes a spring, a plugging cover is fixed inside one end of the third piston cavity away from the second piston cavity, one end of the spring is fixed to the plugging cover, and the other end is fixed to the pushing member for pushing the plunger.

[0013] Furthermore, the push member includes a steel ball.

[0014] Furthermore, a connection structure of an impactless variable lift rocker arm mechanism includes the impactless variable lift rocker arm mechanism described above, one end of the rocker arm mechanism is rotatably connected to a cam, a valve is arranged below the other end of the rocker arm mechanism, and a valve clearance is arranged between the valve and the other end of the rocker arm mechanism.

[0015] Furthermore, a roller shaft arranged parallel to the rocker arm shaft is fixed to one end of the rocker arm, a roller is rotatably sleeved on the roller shaft and connected to the cam.

[0016] Furthermore, the other end of the rocker arm is connected to an adjusting bolt, the top end of the adjusting bolt passes through the rocker arm and is connected to a locking nut, and the bottom end of the adjusting bolt is fixed with an elephant foot.

[0017] The beneficial effects of the present invention are as follows: the present invention adjusts the rotation center of the rocker arm through the piston structure, and can increase the valve lift by increasing the rocker arm ratio. The eccentricity and the direction of the eccentricity can be adjusted according to actual needs and the needs of space arrangement to meet the needs of different engines. Regardless of whether the rocker arm assembly is in a high-lift or low-lift working state, the relative positions of the roller and the elephant foot of the rocker arm remain unchanged, that is, the valve clearance remains unchanged. No matter in which state the rocker arm is working, there is no abnormal impact, no abnormal noise is generated, and the reliability of the entire valve mechanism can be well guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the connection structure of the rocker arm mechanism with variable lift without impact in the present invention;

[0019] Figure 2 It is a schematic diagram of the state of the rocker arm mechanism with variable lift without impact in the present invention when it is not filled with oil;

[0020] Figure 3 It is a schematic diagram of the rocker arm rotation state when the rocker arm mechanism without impact variable lift in the present invention is not filled with oil;

[0021] Figure 4 It is a schematic diagram of the state of the rocker arm mechanism with variable lift without impact in the present invention after oil injection;

[0022] Figure 5 It is a schematic diagram of the rocker arm rotation state after oil injection of the rocker arm mechanism with no impact and variable lift in the present invention;

[0023] Among them, 1—rocker shaft, 2—rocker arm, 3—eccentric ring, 4—oil injection channel, 5—plunger, 6—first piston cavity, 7—second piston cavity, 8—third piston cavity, 9—spring, 10—blocking cover, 11—steel ball, 12—cam, 13—valve, 14—roller shaft, 15—roller, 16—adjusting bolt, 17—locking nut, 18—elephant foot. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the description of the present invention, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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, and therefore cannot be understood as a limitation on the present invention.

[0025] like Figure 1 The impact-free variable lift rocker mechanism shown in FIG5 comprises a rocker shaft 1 and a rocker arm 2 connected to the rocker shaft 1, an eccentric ring 3 is movably sleeved and connected to the rocker shaft 1, and the rocker arm 2 is movably sleeved and connected to the eccentric ring 3. A piston structure is arranged in the structure composed of the rocker arm 2, the eccentric ring 3 and the rocker shaft 1 and along the radial direction of the rocker shaft 1, which can fix the rocker arm 2 and the eccentric ring 3 as a whole or fix the eccentric ring 3 and the rocker shaft 1 as a whole. One end of the piston structure is arranged in the rocker shaft 1, and the other end passes through the eccentric ring 3 and is arranged in the rocker arm 2. An oil injection channel 4 is opened in the rocker shaft 1 for injecting oil into the piston structure.

[0026] The piston structure includes a piston cavity arranged along the radial direction of the rocker shaft 1, and the piston cavity includes a first piston cavity 6, a second piston cavity 7 and a third piston cavity 8 respectively fixed in the rocker shaft 1, the eccentric ring 3 and the rocker 2, and the oil injection channel 4 is connected with the first piston cavity 6. A plunger 5 that can move axially along the piston cavity and an elastic structure for pushing one end of the plunger 5 are arranged in the third piston cavity 8. The elastic structure includes a spring 9 arranged axially along the third piston cavity 8, one end of the spring 9 is fixed in the third piston cavity 8, and the other end is fixed to the steel ball 11. A plug cover 10 is fixed inside the end of the third piston cavity 8 away from the second piston cavity 7, one end of the spring 9 is fixed on the plug cover 10, and the other end is fixed to the steel ball 11 for pushing the plunger 5. The original length of the elastic structure is the same as the length of the third piston cavity 8, and the length of the plunger 5 is greater than the length of the second piston cavity 7, and less than the sum of the length of the second piston cavity 7 and the length of the third piston cavity 8.

[0027] like Figure 1 In the connection structure of the rocker arm mechanism with variable lift without impact shown, a roller shaft 14 arranged in parallel with the rocker arm shaft 1 is fixed to one end of the rocker arm 2, a roller 15 is rotatably sleeved and connected to the roller shaft 14, and the roller 15 is rotatably connected to the cam 12. An adjustment bolt 16 is connected to the other end of the rocker arm 2, the top end of the adjustment bolt 16 passes through the rocker arm 2 and is connected to a locking nut 17, and an elephant foot 18 is fixed to the bottom end of the adjustment bolt 16. A valve 13 is arranged below the elephant foot 18, and a valve clearance is arranged between the valve 13 and the other end of the rocker arm mechanism.

[0028] As attached Figure 2 As shown in FIG. 1 , when there is no oil in the oil injection channel 4 of the rocker arm shaft 1, the plunger 5 is inserted into the first piston cavity 6 under the action of the spring 9, and the other end of the plunger 5 is located in the second piston cavity 7. At this time, when the cam 12 drives the rocker arm 2 to swing, the eccentric ring 3 and the rocker arm shaft 1 remain stationary, and the rocker arm 2 swings back and forth around the axis of the eccentric ring 3. The state of the swinging is as follows: Figure 3 At this time, the variable lift rocker arm mechanism is in the low lift state.

[0029] As attached Figure 4 As shown in the figure, after the oil is filled into the oil filling channel 4, the plunger 5 pushes the steel ball 11 and the spring 9 under the action of the oil pressure, and one end of the plunger 5 is inserted into the second piston cavity 7, and the other end is inserted into the third piston cavity 8. At this time, when the cam 12 drives the rocker arm 2, the eccentric ring 3 together with the rocker arm 2 swings back and forth around the axis of the rocker arm shaft 1, and the state of the swing is as follows: Figure 5 At this time, the variable lift rocker arm mechanism is in the high lift state.

[0030] When the pressure in the oil injection channel 4 decreases to 0, under the action of the spring 9, one end of the plunger 5 is inserted into the first piston cavity 6 and the other end is located in the second piston cavity 7, returning to the low lift state.

[0031] like Figure 1 As shown, after the valve train is assembled, the valve clearance (the clearance between the valve 13 and the elephant foot 18) is adjusted to X.

[0032] When the variable lift rocker arm mechanism is in Figure 3 In the state, the rotation center of the rocker arm 2 is located at the axis of the eccentric ring 3, that is, point O. At this time, the rocker arm ratio is a / b and the valve clearance is X;

[0033] When the variable lift rocker arm mechanism is in Figure 4 In the state, the rotation center of the rocker arm 2 is located at the axis of the rocker arm shaft 1, that is, point O'. At this time, the rocker arm ratio is a' / b', and the valve clearance is still X. Obviously, a' / b'>a / b, so from Figure 3 Switch to Figure 4 After that, the rocker arm ratio increases, the valve lift increases, but the valve clearance remains unchanged, and the relative positions of the roller 15 and the elephant foot 18 remain unchanged. Therefore, no matter in the low lift state or the high lift state, the valve mechanism will not have abnormal impact during operation, which can ensure the reliability of the mechanism and will not have abnormal noise.

[0034] The present invention adjusts the rotation center of the rocker arm 2 through the piston structure, and can increase the valve lift by increasing the rocker arm ratio. The eccentricity and the direction of the eccentricity can be adjusted according to actual needs and the needs of space layout to meet the needs of different engines. Regardless of whether the rocker arm assembly is in a high-lift or low-lift working state, the relative position of the roller 15 and the elephant foot 18 of the rocker arm 2 remains unchanged, that is, the valve clearance remains unchanged. No matter in which state the rocker arm 2 is working, there is no abnormal impact, no abnormal noise will be generated, and the reliability of the entire valve mechanism can be well guaranteed.

[0035] Here, it should be noted that the description of the above technical solution is exemplary, and this specification can be embodied in different forms and should not be interpreted as being limited to the technical solution set forth herein. On the contrary, providing these descriptions will make the disclosure of the present invention thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solution of the present invention is limited only by the scope of the claims. In the case of using "including", "having" and "comprising" described in this specification, unless otherwise used, another part or other parts may also be provided, and the terms used may generally be singular but may also represent plural forms. It should be noted that although the terms "first", "second", "top", "bottom", "one side", "other side", "one end", "other end", etc. may appear and be used in this specification to describe various different components, these components and parts should not be limited by these terms. These terms are only used to distinguish one component and part from another component and part. For example, without departing from the scope of this specification, the first component may be referred to as the second component, and similarly, the second component may be referred to as the first component, and the components at the top and bottom may also be interchanged or converted with each other under certain circumstances; the components at one end and the other end may have the same or different performances.

[0036] Finally, it should be pointed out that the above embodiments are only representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention should be considered to belong to the protection scope of the present invention.

Claims

1. A rocker arm mechanism with variable lift without impact, comprising a rocker arm shaft (1) and a rocker arm (2) connected to the rocker arm shaft (1), characterized in that: An eccentric ring (3) is movably sleeved and connected on the rocker arm shaft (1); the rocker arm (2) is movably sleeved and connected to the eccentric ring (3); a piston structure is arranged in the radial direction of the rocker arm shaft (1) in the structure composed of the rocker arm (2), the eccentric ring (3) and the rocker arm shaft (1); one end of the piston structure is arranged in the rocker arm shaft (1); the other end passes through the eccentric ring (3) and is arranged in the rocker arm (2); an oil injection channel (4) is provided in the rocker arm shaft (1) for injecting oil into the piston structure; The piston structure comprises a piston cavity arranged along the radial direction of the rocker arm shaft (1), wherein a plunger (5) movable axially along the piston cavity and an elastic structure for pushing against one end of the plunger (5) are arranged in the piston cavity; The piston cavity comprises a first piston cavity (6), a second piston cavity (7) and a third piston cavity (8) which are respectively fixed in the rocker arm shaft (1), the eccentric ring (3) and the rocker arm (2); the elastic structure is arranged in the third piston cavity (8); and the oil injection channel (4) is communicated with the first piston cavity (6); The original length of the elastic structure is the same as the length of the third piston cavity (8), the length of the plunger (5) is greater than the length of the second piston cavity (7) and less than the sum of the length of the second piston cavity (7) and the length of the third piston cavity (8); The elastic structure comprises an elastic member arranged along the axial direction of the third piston cavity (8), one end of the elastic member is fixed in the third piston cavity (8), and the other end is fixed to the push member; The elastic member comprises a spring (9), a plugging cover (10) is fixed inside one end of the third piston cavity (8) away from the second piston cavity (7), one end of the spring (9) is fixed to the plugging cover (10), and the other end is fixed to the pushing member for pushing the plunger (5); The push member comprises a steel ball (11).

2. A connection structure of a rocker arm mechanism with variable lift without impact, characterized in that: It comprises the impact-free variable lift rocker arm mechanism as described in claim 1 above, one end of the rocker arm mechanism is rotatably connected to a cam (12), a valve (13) is arranged below the other end of the rocker arm mechanism, and a valve clearance is arranged between the valve (13) and the other end of the rocker arm mechanism.

3. The connection structure of the rocker arm mechanism with shockless variable lift as claimed in claim 2, characterized in that: A roller shaft (14) arranged parallel to the rocker shaft (1) is fixed to one end of the rocker arm (2); a roller (15) is rotatably sleeved on the roller shaft (14); and the roller (15) is rotatably connected to the cam (12).

4. The connection structure of the rocker arm mechanism with shockless variable lift as claimed in claim 2, characterized in that: The other end of the rocker arm (2) is connected with an adjusting bolt (16), the top end of the adjusting bolt (16) passes through the rocker arm (2) and is connected with a locking nut (17), and the bottom end of the adjusting bolt (16) is fixed with an elephant foot (18).

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