Engine rocker arm assembly

Abstract

The utility model relates to the technical field of internal combustion engine rocker arms, and discloses an engine rocker arm assembly which comprises a rocker arm shaft, a first rocker arm, a second rocker arm and a cam mechanism, a first air inlet cam, a second air inlet cam and an exhaust cam are arranged on the cam mechanism, and the first rocker arm and the second rocker arm are arranged on the rocker arm shaft in a sleeved mode. The first air inlet cam drives the first rocker arm to rotate, and the air inlet mechanism is characterized in that the second rocker arm is driven by the second air inlet cam to idle around the rocker arm shaft, a spline housing is arranged between the first rocker arm and the rocker arm shaft and connected with the first rocker arm, and the second rocker arm is driven by the second air inlet cam to rotate around the second rocker arm. The spline housing can move to the position between the second rocker arm and the rocker arm shaft in the axial direction of the rocker arm shaft and is connected with the second rocker arm, and the stroke of the second air inlet cam is larger than that of the first air inlet cam. The reliability is good and the size is small.

Description

Technical Field

[0001] The utility model relates to the technical field of internal combustion engine rocker arms, and particularly relates to an engine rocker arm assembly. Background Art

[0002] Variable valve timing technology has almost become a standard configuration for current engines. In order to further explore the potential of traditional internal combustion engines, engineers have developed variable valve lift technology on this basis. When the two are effectively combined, it provides higher intake and exhaust efficiency for the engine under various working conditions and speeds. While improving power, it also reduces the fuel consumption level, and the rocker arm assembly is an important component structure in variable valves.

[0003] Chinese Patent Document CN117988946A discloses a variable valve structure of an engine. The engine includes a cylinder head and a cylinder cover. A rocker arm shaft, a camshaft, and an intake valve are provided in the cylinder head. It is characterized in that the variable valve structure includes an intake rocker arm one and an intake rocker arm two provided on the rocker arm shaft. The camshaft has an intake cam one and an intake cam two. The lobe tip of the intake cam two is higher than the lobe tip of the intake cam one. The intake rocker arm one abuts against the outer peripheral surface of the intake cam one and can drive the intake valve to open and close. A linkage pin parallel to the rocker arm shaft is inserted through the intake rocker arm one. The linkage pin is located on the side of the rocker arm shaft close to the intake valve and is arranged higher than the rocker arm shaft. The intake rocker arm two abuts against the outer peripheral surface of the intake cam two. A pin hole parallel to the linkage pin and matching the outer diameter of the linkage pin is provided on the intake rocker arm two. A driving assembly is provided on the cylinder cover. The driving assembly is located outside the axis direction of the linkage pin and can push the linkage pin to make part of the linkage pin extend into the pin hole.

[0004] Chinese Patent Document CN113638785B discloses an engine equipped with a variable valve lift drive mechanism. By designing one or two groups of valve rocker arms in the valve drive mechanism into two parts, the sliding rocker arm body and the rotating rocker arm body are connected by a spline or a sliding keyway to form a rocker arm assembly. The sliding rocker arm body and the rotating rocker arm body are both coaxially installed with the rocker arm shaft. The cam drives the sliding rocker arm body to rotate around the rocker arm shaft. Due to the spline fit, the rotation of the sliding rocker arm body drives the rotation of the rotating rocker arm body, and the rotating rocker arm body drives the valve to open and close. At the same time, the sliding rocker arm body has a sliding freedom degree along the axis direction of the rocker arm shaft relative to the rotating rocker arm body. When the electronic control module drives the fork (or pull rod) to axially move the sliding rocker arm body back and forth along the rocker arm shaft, the sliding of the rocker arm relative to the driving cam can be realized to switch the driving cam, so that different profile cams can be used to drive the valve according to the engine working condition requirements, realizing variable valve lift, solving the problems proposed in the background art, and meeting the actual use requirements.

[0005] Chinese patent document CN205779083U discloses a variable valve lift device for a motorcycle tappet engine, comprising a timing gear, wherein the timing gear is connected with a low-speed cam. When the engine is running at a low speed, the low-speed cam drives the rocker arm to rotate. A "hole-bearing" cover plate is arranged in the rear end of the timing gear, and a high-speed cam slider assembly is clamped on the rear side of the low-speed cam. When the engine is running at a high speed, the high-speed cam slider is separated from the low-speed cam and deviates upward due to the centrifugal force. The front end surface of the cover plate is connected with a centrifugal block assembly, and the centrifugal block assembly is connected with a high-speed rotating shaft through a connecting shaft. The middle part of the high-speed rotating shaft is connected with the high-speed cam slider assembly, and the high-speed rotating shaft can rotate in the high-speed cam slider assembly. The other end of the high-speed rotating shaft is slidably connected in the low-speed cam, and the other end of the high-speed rotating shaft can rotate in the low-speed cam. When the engine is running at a high speed, the centrifugal block assembly drives the high-speed rotating shaft to slide due to the centrifugal force, and the high-speed rotating shaft pushes the high-speed cam slider assembly to deviate upward.

[0006] The prior art has the following deficiencies: the variable valves in the prior art documents CN117988946A and CN113638785B have complex overall structures and occupy a large volume; the variable valve lift device of the engine in the prior art document CN205779083U, although simple in structure, cannot be reset to its original position after long-term use, and has poor reliability. Summary of the invention

[0007] The utility model provides an engine rocker arm assembly with good reliability and small size, comprising a rocker arm shaft, a rocker arm 1, a rocker arm 2 and a cam mechanism, wherein the cam mechanism is provided with an intake cam 1, an intake cam 2 and an exhaust cam, the rocker arm 1 and the rocker arm 2 are sleeved on the rocker arm shaft, the intake cam 1 drives the rocker arm 1 to rotate, and is characterized in that the rocker arm 2 rotates idly around the rocker arm shaft under the drive of the intake cam 2, a spline sleeve is provided between the rocker arm 1 and the rocker arm shaft, the spline sleeve is connected to the rocker arm 1, the spline sleeve can be moved along the axial direction of the rocker arm shaft to between the rocker arm 2 and the rocker arm shaft and is partially connected to the rocker arm 2, and the stroke of the intake cam 2 is greater than the stroke of the intake cam 1.

[0008] In order to facilitate the movement of the spline sleeve, a pin in contact with the spline sleeve is provided in the gap between the rocker arm 1 and the rocker arm shaft, and the pin is controlled to extend and retract by a solenoid valve.

[0009] Preferably, the spline sleeve is an external spline, and the rocker arm 1 and the rocker arm 2 are provided with internal splines inside, and the keyway positions of the internal splines of the rocker arm 1 and the rocker arm 2 are aligned with each other.

[0010] In order to facilitate idling, the rocker arm 2 is connected to the rocker arm 1 through a torsion spring, and the torsion spring makes the rocker arm 2 stick to the intake cam 2.

[0011] Further, the spring end of the torsion spring is sleeved on the first rocker arm, and the bent end of the torsion spring is sleeved on the second rocker arm.

[0012] To facilitate the repeated switching of the valve, a return spring is sleeved on the rocker arm shaft. A bushing is provided between the second rocker arm and the rocker arm shaft. One end of the bushing abuts against the spline sleeve, and the other end abuts against the return spring.

[0013] To facilitate fixing and resetting, the rocker arm shaft is fixed on the rocker arm shaft support seat. One end of the return spring abuts against the rocker arm shaft support seat, and the other end abuts against the bushing.

[0014] The utility model has the following beneficial effects:

[0015] 1. Lightweight, simple structure, and small volume. The switching device of the two intake cams of the utility model is arranged between two rocker arms and a rocker arm shaft. Only one solenoid valve is externally provided to control the movement of the spline sleeve, so as to realize the switching of the intake cams. At low speeds, it is driven by the first intake cam, and at high speeds, it is driven by the second intake cam, and the two rocker arms operate simultaneously, so that the engine always operates in the best state.

[0016] 2. High reliability in use. The elastic change of the spring is stable, and the spline sleeve and the bushing are not easily detached between the rocker arm and the rocker arm shaft, so that the reset reliability is good, and it is firm and durable. Description of the Drawings

[0017] Figure 1 Schematic diagram of an embodiment of the engine rocker arm assembly at a certain speed;

[0018] Figure 2 Schematic diagram of an embodiment of the engine rocker arm assembly at high speed;

[0019] Figure 3 Schematic diagram of the bushing;

[0020] Figure 4 Schematic diagram of the spline sleeve;

[0021] Figure 5 Schematic diagram of the torsion spring;

[0022] Figure 6 Schematic diagram of the first rocker arm;

[0023] Figure 7 Schematic diagram of the second rocker arm;

[0024] Figure 8 Schematic diagram of the cam mechanism;

[0025] Figure 9 Side view of the cam mechanism. Detailed Implementation Modes

[0026] The following is a further detailed description through specific embodiments:

[0027] 1. The reference numerals in the attached drawings of the specification include: rocker shaft 1, first rocker 2, second rocker 3, first intake cam 4, second intake cam 5, exhaust cam 6, spline sleeve 7, base circle 8, profile 9, ejector pin 10, solenoid valve 11, internal spline 12, return spring 13, rocker shaft support seat 14, bushing 15, external spline 16, torsion spring 17, spring end 18, and bending end 19.

[0028] Embodiment 1

[0029] As Figures 1-9 shown, an engine rocker assembly includes a rocker shaft 1, a first rocker 2, a second rocker 3, and a cam mechanism. The cam mechanism is provided with a first intake cam 4, a second intake cam 5, and an exhaust cam 6. The first rocker 2 and the second rocker 3 are sleeved on the rocker shaft 1. The first intake cam 4 drives the first rocker 2 to rotate. A spline sleeve 7 is provided between the first rocker 2 and the rocker shaft 1. The spline sleeve 7 connects the first rocker 2 and can move axially along the rocker shaft 1 to between the second rocker 3 and the rocker shaft 1 and be partially connected to the second rocker 3. A return spring 13 is sleeved on the rocker shaft 1. A bushing 15 is provided between the second rocker 3 and the rocker shaft 1. One end of the bushing 15 abuts against the spline sleeve 7, and the other end abuts against the return spring 13. The second rocker 3 idles around the bushing 15 under the drive of the second intake cam 5. The stroke of the second intake cam 5 is greater than the stroke of the first intake cam 4.

[0030] The base circles 8 of the second intake cam 5 and the first intake cam 4 are the same, but the profiles 9 are different. The profile 9 of the second intake cam 5 is larger than the profile 9 of the first intake cam 4. Therefore, the profile 9 of the second intake cam 5 completely envelopes the profile 9 of the first intake cam 4.

[0031] An ejector pin 10 in contact with the spline sleeve 7 is provided in the gap between the first rocker 2 and the rocker shaft 1. The telescopic movement of the ejector pin 10 is controlled by a solenoid valve 11.

[0032] The spline sleeve 7 is an external spline 16. Internal splines 12 are provided inside the first rocker 2 and the second rocker 3. The keyway positions of the internal splines 12 of the first rocker 2 and the second rocker 3 are aligned with each other.

[0033] The second rocker 3 is connected to the first rocker 2 through a torsion spring 17. The torsion spring 17 makes the second rocker 3 abut against the second intake cam 5.

[0034] The spring end 18 of the torsion spring 17 is sleeved on the first rocker 2, and the bending end 19 of the torsion spring 17 is sleeved on the second rocker 3.

[0035] The rocker shaft 1 is fixed on the rocker shaft support seat 14. One end of the return spring 13 abuts against the rocker shaft support seat 14, and the other end abuts against the bushing 15.

[0036] When the engine is at normal speed, the engine rocker assembly is as Figure 1 shown. The intake cam 4 drives the rocker 2. The rocker 2 drives the spline sleeve 7 to reciprocate around the rocker shaft 1, so that the rocker 2 drives the valve to work. The rocker 3 always abuts against the intake cam 5 through the torsion spring 17. The rocker 3 idles around the bushing 15 under the drive of the intake cam 5. When the engine runs to the set speed, the spline sleeve 7 in the rocker shaft 1 can move a certain distance towards the rocker 3 under the actuation of the ejector pin 10 of the solenoid valve 11, which drives the bushing 15 to slide. The bushing 15 compresses the return spring 13, so that the spline sleeve 7 enters the rocker 3 and is connected to the internal spline 12 of the rocker 3. Finally, the rocker 3 is connected to the spline sleeve 7 and the rocker 2. The intake cam 5 drives the rocker 3 to drive the rocker 2 to actuate. Since the profile 9 of the intake cam 5 envelopes the intake cam 4, the valve operates according to the profile 9 of the intake cam 5 at this time, and the intake cam 4 and the rocker 2 are disengaged during valve actuation.

[0037] As Figure 2 shown, when the engine speed deviates from the set speed, the ejector pin 10 of the solenoid valve 11 disengages from the spline sleeve 7. The bushing 15 returns to its original position under the action of the return spring 13. The bushing 15 pushes the spline sleeve 7 away from the rocker 3. At this time, the rocker 3 idles around the bushing 15 again. The rocker 2 contacts the intake cam 4, and the intake cam 4 actuates to drive the rocker 2 to continue to work normally. This mechanism can switch between the two intake cams, so that the engine always operates in the best state.

[0038] The above are only embodiments of the present utility model. Specific structures and common knowledge such as characteristics that are well-known in the art are not described in detail herein. Those of ordinary skill in the art know all the common general technical knowledge in the technical field to which the utility model belongs before the filing date or the priority date, can know all the prior art in this field, and have the ability to apply conventional experimental means before this date. Those of ordinary skill in the art can, under the inspiration given in this application and in combination with their own abilities, improve and implement this solution. Some typical well-known structures or well-known methods should not become an obstacle for those of ordinary skill in the art to implement this application. It should be noted that for those skilled in the art, without departing from the structure of the present utility model, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present utility model, and these will not affect the implementation effect of the present utility model and the practicality of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners and the like recorded in the specification can be used to interpret the content of the claims.

Claims

1. An engine rocker arm assembly, comprising a rocker arm shaft (1), a rocker arm 1 (2), a rocker arm 2 (3) and a cam mechanism, wherein the cam mechanism is provided with an intake cam 1 (4), an intake cam 2 (5) and an exhaust cam (6), the rocker arm 1 (2) and the rocker arm 2 (3) are sleeved on the rocker arm shaft (1), the intake cam 1 (4) drives the rocker arm 1 (2) to rotate, and is characterized in that: The rocker arm 2 (3) is driven by the intake cam 2 (5) to rotate idly around the rocker arm shaft (1); a spline sleeve (7) is provided between the rocker arm 1 (2) and the rocker arm shaft (1); the spline sleeve (7) is connected to the rocker arm 1 (2); the spline sleeve (7) can move along the axial direction of the rocker arm shaft (1) to between the rocker arm 2 (3) and the rocker arm shaft (1) and is partially connected to the rocker arm 2 (3); the stroke of the intake cam 2 (5) is greater than the stroke of the intake cam 1 (4).

2. The engine rocker arm assembly according to claim 1, characterized in that: A pin (10) in contact with the spline sleeve (7) is provided in the gap between the rocker arm 1 (2) and the rocker arm shaft (1), and the extension and retraction of the pin (10) is controlled by a solenoid valve (11).

3. The engine rocker arm assembly according to claim 2, characterized in that: The spline sleeve (7) is an external spline (16), and the rocker arm 1 (2) and the rocker arm 2 (3) are provided with internal splines (12) inside, and the keyway positions of the internal splines (12) of the rocker arm 1 (2) and the rocker arm 2 (3) are aligned with each other.

4. The engine rocker arm assembly according to any one of claims 1 to 3, characterized in that: The second rocker arm (3) is connected to the first rocker arm (2) via a torsion spring (17), and the torsion spring (17) enables the second rocker arm (3) to be attached to the second intake cam (5).

5. The engine rocker arm assembly according to claim 4, characterized in that: The spring end (18) of the torsion spring (17) is sleeved on the first rocker arm (2), and the bent end (19) of the torsion spring (17) is sleeved on the second rocker arm (3).

6. The engine rocker arm assembly according to claim 5, characterized in that: A return spring (13) is sleeved on the rocker arm shaft (1), a shaft sleeve (15) is provided between the second rocker arm (3) and the rocker arm shaft (1), one end of the shaft sleeve (15) is pressed against the spline sleeve (7), and the other end is pressed against the return spring (13).

7. The engine rocker arm assembly according to claim 6, characterized in that: The rocker shaft (1) is fixed on a rocker shaft support seat (14); one end of the return spring (13) is pressed against the rocker shaft support seat (14) and the other end is pressed against the shaft sleeve (15).

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