CN114909199A

CN114909199A - Rocker arm mechanism driven by variable valve of engine

Info

Publication number: CN114909199A
Application number: CN202110184061.8A
Authority: CN
Inventors: 朱汝杰; 郉宝亮; 奚正
Original assignee: Shanghai Youshun Automobile Technology Co ltd
Current assignee: Shanghai Youshun Automobile Technology Co ltd
Priority date: 2021-02-10
Filing date: 2021-02-10
Publication date: 2022-08-16

Abstract

The utility model provides a rocking arm mechanism for variable valve actuation of engine, including first rocking arm, second rocking arm and a coupling mechanism, the one end of first rocking arm and the one end of second rocking arm are connected on a root axis with rotating, the other end of first rocking arm is close to the valve of engine, the other end of second rocking arm is close to the cam of engine, coupling mechanism is including connecting piston and link mechanism, the connecting piston is settled in first rocking arm or second rocking arm, link mechanism links to each other with the one end of connecting the piston with rotating, link mechanism's flexible length that makes coupling mechanism between first rocking arm and second rocking arm changes, change the motion that the engine cam transmitted to the engine valve. The rocker arm mechanism of the invention can be used for cylinder deactivation and engine braking of an engine.

Description

Rocker arm mechanism driven by variable valve of engine

Technical Field

The invention relates to the field of machinery, in particular to the field of engine valve driving, and particularly relates to a rocker mechanism driven by a variable valve of an engine.

Background

Conventional valve actuation for vehicle engines is well known in the art and has been in use for over a hundred years. Conventional valve actuation utilizes a conventional valve actuator (including a rocker arm) to control the motion of an engine valve for conventional spark operation of the engine. However, due to additional demands on engine fuel efficiency, exhaust emissions and engine braking, more and more engines employ variable valve actuation, including engine deactivation which completely eliminates valve motion, and engine braking has also been widely used for commercial vehicle engines.

Chinese invention patent CN104411925B (2018) discloses a system, method and apparatus for controlling variable valve operation in an automotive engine, two cams having different lift profiles, two rocker arms respectively straddling the two cams, the two rocker arms being locked by latches to transfer the different cam lift profiles to the valves of the engine. The invention is that the overhead cam acts on a roller at the center of a rocker arm, and the application of the overhead cam is limited to passenger cars.

Chinese invention patent CN102373979B (2015) discloses a rocker arm mechanism for engine cylinder deactivation, comprising an outer rocker arm and an inner rocker arm, wherein the inner and outer rocker arms are connected by a latch to transfer the motion of a cam to a valve. When the latch connection is disconnected, the motion of the cam is lost, the valve lift is zero, and the engine is deactivated. Also, the invention is an overhead cam acting on a roller in the center of a rocker arm, and the application is limited to passenger cars.

U.S. Pat. No. 5,537,976(1996) discloses another two-stroke engine braking apparatus and method, which uses cam actuation, hydraulic connections, high speed solenoid valves and electronic control to achieve different valve motions, to achieve engine ignition or engine braking. Since the solenoid valve needs to be opened at least once during each cycle, there are particularly high demands on the reliability and durability of the solenoid valve. Coupled with other problems with hydraulic actuation such as control of valve seating velocity, cold start of the engine, etc., the invention has not been practical.

Still another two-stroke engine braking apparatus and method is disclosed in U.S. Pat. No. 6,293,248 (2001). In order to achieve two-stroke engine braking on a four-stroke engine, in addition to requiring four cams, four rocker arms must be employed: two exhaust rocker arms (one for braking) and two intake rocker arms (one for braking) are complex in structure and control, and are hydraulically driven to open the valves of the engine.

Disclosure of Invention

The invention aims to provide a rocker arm mechanism driven by a variable valve of an engine, and aims to solve the technical problems that in the prior art, the structure and control are complex, the reliability and durability of a hydraulically-driven opening valve are poor, and the application is limited.

The present invention provides a rocker arm mechanism for variable valve actuation of an engine, comprising: first rocking arm, second rocking arm and a coupling mechanism, the one end of first rocking arm and the one end rotary type of second rocking arm connect on an axle, the valve of engine is close to the other end of first rocking arm, the other end of second rocking arm is close to the cam of engine, coupling mechanism including connecting piston and link mechanism, the connecting piston settle at first rocking arm or second rocking arm, link mechanism link to each other with the one end rotary type of connecting the piston, the other end of connecting the piston is close to first rocking arm or the second rocking arm of not settling the connecting piston, link mechanism's flexible messenger connects the piston and does not settle the distance between the first rocking arm or the second rocking arm of connecting the piston and change, changes the motion that the engine cam transmitted for the engine valve.

The engine further comprises an anti-flying off spring, wherein the anti-flying off spring pushes the first rocker arm to a valve of the engine and pushes the second rocker arm to a cam of the engine.

Furthermore, the connecting rod mechanism comprises a first connecting rod and a second connecting rod, one end of the first connecting rod is rotatably connected with one end of the second connecting rod, the other end of the first connecting rod is rotatably connected with the connecting piston, the other end of the second connecting rod is rotatably connected with the first rocker arm or the second rocker arm, an included angle between the first connecting rod and the second connecting rod is more than 0 degree and less than or equal to 180 degrees, when the included angle is 180 degrees, the first connecting rod and the second connecting rod are arranged on the axis of the connecting piston, the connecting rod mechanism is completely extended, the length of the connecting mechanism between the first rocker arm and the second rocker arm is the largest, the motion of the engine cam is transmitted to the engine valve to the maximum extent, when the included angle is reduced, the connecting rod mechanism is contracted, the length of the connecting mechanism between the first rocker arm and the second rocker arm is reduced, and the motion transmitted to the engine valve by the engine cam is reduced.

Furthermore, the connecting mechanism further comprises a driving spring, and the driving spring enables the connecting rod mechanism to extend.

Further, the connecting mechanism further comprises a driving piston, and the driving piston enables the connecting rod mechanism to retract.

Furthermore, the rocker arm assembly further comprises a stop mechanism, and the stop mechanism limits the first rocker arm and the second rocker arm to rotate on the shaft.

Furthermore, the valve bridge positioning mechanism of the engine further comprises a positioning piece, wherein the positioning piece is fixed on the first rocker arm and connected with the valve of the engine or the valve bridge above the valve.

The invention also provides an engine braking device, which comprises a braking rocker arm and a braking cam, wherein the braking rocker arm and the rocker arm mechanism are arranged on the rocker arm shaft of the engine side by side, when the connecting rod mechanism of the rocker arm mechanism is in a retraction state, the braking rocker arm is in a braking state, the motion of the braking cam is transmitted to the valve of the engine, and the valve motion for braking the engine is generated, wherein the rocker arm mechanism is the rocker arm mechanism.

Compared with the prior art, the invention has positive and obvious effect. The rocker arm mechanism of the invention is composed of a first rocker arm and a second rocker arm, the front rocker arm and the second rocker arm are connected or separated through the extension and contraction of the connecting rod mechanism, the valve motion of an engine is generated or lost, the conversion between the ignition of the engine and the cylinder deactivation or braking of the engine is realized, the rocker arm mechanism has the advantages of simple and reliable structure, easy manufacture and assembly, wide application and the like, particularly, the lifting amount of the connecting rod mechanism is large (namely, the variable range of the included angle between the first connecting rod and the second connecting rod is large), and the rocker arm mechanism can be applied to the variable valve driving of the engine with large lift, including the cylinder deactivation of the engine without the whole valve lift and the braking of the engine with large stroke.

Drawings

Fig. 1 is a schematic diagram of a link mechanism in a retracted state in embodiment 1 of the engine variable valve actuation rocker mechanism of the present invention.

Fig. 2 is a schematic diagram showing the extended state of the link mechanism in embodiment 1 of the variable valve actuation rocker mechanism of the engine of the invention.

Fig. 3 is a schematic diagram showing a second connection mode of the first rocker arm in the extended state of the link mechanism in embodiment 1 of the variable valve actuation rocker mechanism of the engine of the invention.

Detailed Description

Example 1:

fig. 1 and 2 are used to describe embodiment 1 of the variable valve actuation rocker mechanism of the engine of the present invention. The rocker arm mechanism in the figure comprises a first rocker arm 10, a second rocker arm 210 and a connecting mechanism 100, wherein one end of the first rocker arm 10 and one end of the second rocker arm 210 are rotatably connected to a shaft 120, the other end of the first rocker arm 10 is close to a valve 300 of an engine, and the other end of the second rocker arm 210 is close to a cam 230 of the engine. The connecting mechanism 100 includes a connecting piston 160 and a link mechanism 150, and the connecting piston 160 and the link mechanism 150 are both disposed on the second rocker arm 210: the connecting piston 160 is disposed on the second rocker arm 210 (specifically, may be disposed in a mating piston cavity of the second rocker arm 210), one end of the linkage mechanism 150 is rotatably connected to the second rocker arm 210 at 153, the other end of the linkage mechanism 150 is rotatably connected to one end 162 of the connecting piston 160, the other end 164 of the connecting piston 160 is adjacent to the first rocker arm 10 where the connecting piston 160 is not disposed, and extension and retraction of the linkage mechanism 150 changes the length of the connecting mechanism 100 between the first rocker arm 10 and the second rocker arm 210 (see the length change between 153 and 164 in fig. 1 and 2), thereby changing the motion transmitted by the engine cam 230 to the engine valve 300. Of course, in another embodiment, the connecting piston 160 and the linkage 150 are both disposed in the first rocker arm 10: the connecting piston 160 is also positioned on the first rocker arm 10 with the other end 164 of the connecting piston 160 adjacent to the second rocker arm 210 (and possibly the connecting member 20) where the connecting piston is not positioned.

The link mechanism 150 includes a first link 152 and a second link 154, one end of the first link 152 and one end of the second link 154 are rotatably connected by a pin 151 (which may be spherical), the other end of the first link 152 is rotatably connected to one end 162 of the connecting piston 160, the other end of the second link 154 is rotatably connected to the second rocker 210 (when the connecting piston 160 and the link mechanism 150 are both disposed on the first rocker 10 and the other end of the second link 154 is connected to the first rocker 10) by a pin 153 (which may be spherical), an included angle between the first link 152 and the second link 154 is from greater than 0 ° (a folded angle, which is an angle greater than 0 ° and less than 180 ° (inclusive of the folded angle shown in fig. 1)) to equal to or less than a straight angle (inclusive), and when the included angle is a straight angle (180 °, see fig. 2), the first link 152 and the second link 154 are on an axis of the connecting piston 160 (an axis of a moving direction of the connecting piston 160), at this time, the connecting piston 160 is locked with the link mechanism 150 and the second rocker arm 210 (or the first rocker arm 10) and cannot move relatively (see fig. 2), the length of the connecting mechanism 100 between the first rocker arm 10 and the second rocker arm 210 (the length between 153 and 164) is the largest, and the motion of the engine cam 230 is maximally transmitted to the engine valve 300; when the drive piston 130 pushes on the linkage mechanism 150 such that the included angle is reduced (less than 180), the linkage mechanism 150 retracts and unlocks (see fig. 1), the length of the linkage mechanism 100 between the first rocker arm 10 and the second rocker arm 210 is reduced (the length between 153 and 164 in fig. 1 is less than that in fig. 2), and the motion imparted to the engine valve 300 by the engine cam 230 is reduced or even completely lost (engine deactivation).

The connecting mechanism 100 further includes a drive spring 156, and the link mechanism 150 can be completely unfolded (extended) by the force of the drive spring 156, that is, the first link 152 and the second link 154 are unfolded on the axis of the connecting piston 160.

The pre-load of the drive spring 156 satisfies: when the angle between the first link 152 and the second link 154 is small, the link mechanism 150 can be smoothly unfolded, thereby obtaining a large stroke.

The linkage mechanism also includes an actuator piston, and when the actuator piston 130 pushes on the linkage mechanism 150 such that the included angle is reduced (less than 180 °), the linkage mechanism 150 retracts and unlocks (see fig. 1), the length of the linkage mechanism 100 between the first rocker arm 10 and the second rocker arm 210 is reduced (the length between 153 and 164 in fig. 1 is less than that in fig. 2), and the motion imparted by the engine cam 230 to the engine valve 300 is reduced or even completely lost (engine deactivation).

Note that the drive spring 156 also has a fly-off prevention function. If desired, however, an anti-fly off spring 198 disposed between the first rocker arm 10 and the second rocker arm 210 may also be added. The second rocker arm 210 is urged toward the engine cam 230 by the anti-fly-off spring 198, which may be mounted elsewhere and functions to assist the drive spring 156 in reducing the impact between the front and second rocker arms.

In the embodiment, the stop mechanism is arranged at the position 122 between the first rocker arm 10 and the second rocker arm 210, so that the mutual rotation of the first rocker arm 10 and the second rocker arm 210 on the shaft 120 is limited to be too large, and the carrying and the installation are convenient.

The operation process of this embodiment is as follows: when the engine needs to be deactivated (the conventional valve motion of the engine is eliminated), the cylinder deactivation control valve (not shown) opens the oil supply, the engine oil supplies oil to the driving piston 130 through an oil passage (such as an axial oil hole 211 in the rocker shaft 205), the oil pressure pushes the driving piston 130 out (upward in the figure), the connecting mechanism 150 which is fully extended to a flat angle in fig. 2 is pushed to the retracted position shown in fig. 1, the length of the connecting mechanism 100 between the second rocker arm 210 and the first rocker arm 10 is reduced (the length between 153 and 164 in fig. 1 is smaller than that in fig. 2), the motion of the first rocker arm second rocker arm cam 230 driving the second rocker arm 210 is absorbed (lost), the first rocker arm 10 remains stationary, the motion of the valve 300 is zero, and the engine is deactivated. In this process, the drive spring is compressed due to the reduction in length.

When it is desired to restore the normal valve motion of the engine, the cylinder deactivation control valve (not shown) disconnects oil discharge, the driving piston 130 loses the effect of oil pressure (a return spring may be added to the driving piston 130), so that the driving spring 156 extends from a compressed state, the link mechanism 150 is unfolded from a contracted state (the included angle between the first link 152 and the second link 154 is smaller than a flat angle in fig. 1) to a straight state (the included angle between the first link 152 and the second link 154 is a flat angle in fig. 2), a lock is formed between the connecting piston 160 and the second rocker arm 210 (or the first rocker arm 10) through the link mechanism 150, and the length (the length between 153 and 164) of the connecting mechanism 100 between the first rocker arm 10 and the second rocker arm 210 is the largest. The motion of the engine cam 230 is transmitted to the engine valve 300 via the roller 235, the second rocker arm 210, the link mechanism 150, the connecting piston 160, the first rocker arm 10 (the connecting member 20), the elephant foot mechanism 50, the valve bridge 400 (a valve cap, not shown).

Note that the above description applies to both the driving of the exhaust valves and the intake valves of the engine.

Meanwhile, one end of the first rocker arm 10 may be rotatably connected to the rocker shaft 205. As shown in fig. 3

The above description contains many different embodiments and should not be construed as limiting the scope of the invention but as merely representative of some of the specific embodiments from which many other variations may be made. For example, the engine braking methods or systems shown herein may be used not only in overhead cam engines, but also in push rod/push tube engines; not only can open a single valve, but also can open double valves; the valve can be used for driving an exhaust valve and an intake valve; the number, size, shape, phase, etc. of the bosses included in the brake cam can vary.

In addition, the connecting mechanism shown here may be not only a piston-spring mechanism, but also other mechanisms, such as hydraulic, pneumatic, electromagnetic, mechanical, etc., and combinations thereof; not only integrated within the rocker arm, but also located on other parts of the engine. The type, shape, size and mounting position of the connection mechanism, the design of the oil passage, the structure and arrangement of the liquid flow control valve, etc. may be varied.

The second rocker arm and, where the rocker arm mechanism herein may further comprise a locating mechanism for the engine valve bridge, such as a locating tab secured to the first rocker arm and connected to the engine valve or the valve bridge above the valve.

Furthermore, the rocker arm mechanism herein may also be used for engine braking, in which case there is provided an engine braking device comprising a braking rocker arm and a braking cam, the braking rocker arm being arranged alongside the rocker arm mechanism on a rocker shaft of the engine, the braking rocker arm being in a braking state when the linkage mechanism of the rocker arm mechanism is in a retracted state, transmitting the motion of the braking cam to a valve of the engine, producing a valve motion for engine braking.

The type of the brake rocker arm mechanism may be various, and may be a single hydraulic dedicated brake rocker arm, a fixed chain type brake rocker arm, or the like, in addition to the split type (front and second rocker arms) rocker arm according to the present invention.

The scope of the invention should, therefore, be determined not with reference to the above detailed description, but instead should be determined with reference to the appended claims along with their legal equivalents.

Claims

1. A rocker arm mechanism for variable valve actuation of an engine, comprising: the engine valve connecting device comprises a first rocker arm, a second rocker arm and a connecting mechanism, wherein one end of the first rocker arm and one end of the second rocker arm are rotatably connected to a shaft, the other end of the first rocker arm is close to a valve of an engine, the other end of the second rocker arm is close to a cam of the engine, the connecting mechanism comprises a connecting piston and a connecting rod mechanism, the connecting piston is arranged on the first rocker arm or the second rocker arm, the connecting rod mechanism is rotatably connected with one end of the connecting piston, the other end of the connecting piston is close to the first rocker arm or the second rocker arm which is not provided with the connecting piston, the length of the connecting mechanism between the first rocker arm and the second rocker arm is changed due to the expansion and contraction of the connecting rod mechanism, and the motion of the engine cam transmitted to the engine valve is changed.

2. The rocker mechanism of claim 1, wherein: the anti-drop device further comprises an anti-drop spring, wherein the anti-drop spring pushes the first rocker arm to a valve of the engine and pushes the second rocker arm to a cam of the engine.

3. The rocker mechanism of claim 1, wherein: the connecting rod mechanism comprises a first connecting rod and a second connecting rod, one end of the first connecting rod is rotatably connected with one end of the second connecting rod, the other end of the first connecting rod is rotatably connected with the connecting piston, the other end of the second connecting rod is rotatably connected with the first rocker arm or the second rocker arm, an included angle between the first connecting rod and the second connecting rod is more than 0 degree and less than or equal to 180 degrees, when the included angle is 180 degrees, the first connecting rod and the second connecting rod are arranged on the axis of the connecting piston, the connecting rod mechanism is completely extended, the length of the connecting mechanism between the first rocker arm and the second rocker arm is the largest, the motion of the engine cam is transmitted to the engine valve to the maximum extent, when the included angle is reduced, the connecting rod mechanism is contracted, the length of the connecting mechanism between the first rocker arm and the second rocker arm is reduced, and the motion transmitted to the engine valve by the engine cam is reduced.

4. The rocker mechanism of claim 1, wherein: the linkage mechanism further includes a drive spring that causes the linkage mechanism to deploy.

5. The rocker mechanism of claim 1, wherein: the linkage mechanism further includes a drive piston that retracts the linkage mechanism.

6. The rocker mechanism of claim 1, wherein: the stop mechanism limits mutual rotation of the first rocker arm and the second rocker arm on the shaft.

7. The rocker mechanism of claim 1, wherein: the positioning mechanism of the engine valve bridge is further included, the valve bridge positioning mechanism comprises a positioning sheet, and the positioning sheet is fixed on the first rocker arm and connected with the valve of the engine or the valve bridge above the valve.

8. An engine braking device characterized in that: comprising a braking rocker arm and a braking cam, said braking rocker arm being arranged on the engine alongside the rocker mechanism, and when the linkage mechanism of the rocker mechanism is in a retracted state, the braking rocker arm is in a braking state, transmitting the motion of the braking cam to the valve of the engine, producing a valve motion for engine braking, wherein said rocker mechanism is a rocker mechanism according to any of claims 1-7.