WO2010108374A1

WO2010108374A1 - Engine distribution mechanism with adjustable lift air valve

Info

Publication number: WO2010108374A1
Application number: PCT/CN2009/076062
Authority: WO
Inventors: 刘和义; 王建军
Original assignee: 奇瑞汽车股份有限公司
Priority date: 2009-03-27
Filing date: 2009-12-25
Publication date: 2010-09-30
Also published as: CN101503973A

Abstract

An engine distribution mechanism with adjustable lift air valve, including a cam (11) arranged on a cam shaft (10), a finger-shaped rocker arm (20) arranged below the cam (11) which contacts against and can rotate with the bearing of the rocker arm (20), a vertically-adjustable tappet (30) arranged below one end of the rocker arm (20) and an air valve (40) arranged below the other end. The rocker arm (20) can rotate around its interface with the tappet (30), and a return spring (50) is provided on the rod of the air valve (40). The position of the tappet (30) can be adjusted vertically so as to adjust air valve lift. The distribution mechanism is simple in structure, and works stably and reliably.

Description

Valve valve with adjustable valve lift

Technical field

The invention relates to an engine valve distribution mechanism with adjustable valve lift, belonging to the technical field of engine manufacturing. Background technique

In the conventional engine air distribution mechanism, the three characteristic parameters of the valve: the valve opening phase, the valve opening continuous angle and the valve lift value are fixed during the operation of the engine. With the change of engine speed and load, the optimal characteristics of the valve train are different. For example: In order to increase the power of the engine, it is necessary to open and delay the closing of the intake valve, and increase the intake valve. In order to increase the low speed torque of the engine, a smaller valve lift is required. In recent years, due to the increasing emphasis on the fuel economy of automobiles and the environmental protection of exhaust emissions, there is also an urgent need for a gas distribution mechanism with variable valve lift to meet the different needs of various operating conditions of the engine. Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine valve train having an adjustable valve lift, which is simple in construction, stable in operation, improved in engine power, and improved in fuel economy.

To achieve the above object, the present invention adopts the following technical solutions:

An engine valve adjusting mechanism with adjustable valve lift includes a cam disposed on a cam shaft, and a lower side of the cam is provided with a finger rocker arm, and the cam abuts a bearing disposed on the finger rocker arm Together with the rotary fit, the lower side of one end of the finger type rocker arm is provided with a tappet that is adjustable up and down, and the lower side of the other end is provided with a valve, and the finger type rocker arm can be engaged with the tappet Rotating, the valve body of the valve is sleeved with a return spring.

It can be seen from the above technical solution that the position of the tappet in the present invention is adjustable up and down, and since the finger type rocker arm can rotate around the mating portion thereof, the position of the finger rocker arm will also follow The adjustment of the column is adjusted up and down, and the position of the finger rocker determines the size of the valve lift, so that the lift of the valve is adjusted. As can be seen from the above, the present invention is simple in construction and stable in operation.

The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. DRAWINGS

1, 2, and 3 are schematic structural views of different angles of the present invention; Figure 4 is a schematic structural view of a tappet;

Figure 5 is a schematic structural view of an eccentric shaft;

Figure 6 is a schematic structural view of a drive mechanism;

Figure 7 is a schematic view showing the structure of the finger type rocker arm. detailed description

As shown in FIG. 1 to FIG. 3, the present invention provides an engine valve distribution mechanism with adjustable valve lift, comprising a cam 11 disposed on a camshaft 10, and a finger rocker arm disposed on a lower side of the cam 11 20, the cam 11 abuts against the bearing disposed on the finger type rocker arm 20 and constitutes a rotational fit, and the lower side of one end of the finger type rocker arm 20 is provided with a tappet 30 whose position is adjustable up and down, and the lower side of the other end A valve 40 is disposed, and the finger type rocker arm 20 is rotatable about a mating portion thereof with the tappet 30, and a return spring 50 is sleeved on the rod body of the valve 40.

In operation, the disc-shaped cam 11 rotates with the cam shaft 10, since the lower side of one end of the finger type rocker arm 20 is provided with a tappet 30 which is adjustable in position up and down, and the finger type rocker arm 20 can be wound around the tappet 30 The joint is rotated. Therefore, when the cam 11 is rotated to abut against the bearing on the finger type rocker arm 20 at the end with the longest diameter, the finger type rocker arm 20 also rotates around its mating portion with the tappet 30, finger type The other end of the rocker arm 20 then presses the valve 40 downward to cause the valve to open with a certain lift; the cam 11 continues to rotate, and the valve 40 returns to its original position by the return spring 50.

In the present invention, since the position of the tappet 30 is adjustable up and down, the position of the finger rocker arm 20 can also be adjusted up and down, and the position of the finger rocker arm 20 directly determines the lift of the valve 40. Therefore, the present invention adjusts the lift of the valve 40 by adjusting the position of the tappet 30, thereby satisfying the different requirements of the valve train for various operating conditions of the engine.

The structural features and modes of operation of the finger type rocker arm 20 of this embodiment are described in the patent document No. 02819736.4.

As a preferred embodiment of the present invention, as shown in FIG. 2, FIG. 3, and FIG. 4, the top of the tappet 30 is provided with a convex portion 31, and the bottom end surface of the finger type rocker arm 20 is provided with a concave portion 21, and the concave portion 21 is provided. Engaged with the convex portion 31, as shown in Fig. 7, the finger type rocker arm 20 is rotatable about the fitting portion of the convex portion 31 and the concave portion 21.

The fitting manner of the above-mentioned tappet 30 and the concave and convex of the finger type rocker arm 20 not only facilitates the stable operation of the entire valve train, but also simplifies the structure and improves the reliability of operation.

As another preferred embodiment of the present invention, a part of the column body of the tappet 30 is arranged in a spring shape, and the rigidity of the spring-like column body is smaller than the rigidity of the return spring 50. A part of the column of the tappet 30 is arranged in a spring shape, that is, the upper column of the tappet 30 can be arranged in a spring shape, and the lower column body can be arranged in a solid shape; or the lower column of the tappet 30 can be arranged. It is spring-like, and the upper column body is provided in a solid shape; the column bodies on the upper and lower sides of the tappet 30 may be provided in a solid shape, and the intermediate portion between the upper and lower sides may be arranged in a spring shape. Moreover, since the stiffness of the spring-like cylinder of the tappet 30 is less than the stiffness of the return spring 50, when the cam 11 drives the valve 40 through the finger-type rocker arm 20, the finger-type rocker arm 20 first makes the spring of the tappet 30 The column of the shaped portion is compressed, and only after the column of the spring-like portion of the tappet 30 reaches an uncompressible extent, the valve 40 will act, thereby allowing the lift of the valve 40 to be further adjusted.

There are various implementations for adjusting the position of the tappet 30 up and down. For example, the rack and pinion mechanism is used to drive the tappet 30 to move up and down. As a preferred embodiment of the present invention, reference is made to FIG. 1 to FIG. 3 and FIG. The upper side of the tappet 30 is disposed in a spring shape, and the lower side of the tappet 30 is provided with a hole 32 penetrating the column body, the hole 32 is provided with an eccentric shaft 60, and one side of the eccentric shaft 60 is provided with a driving mechanism for driving the rotation thereof. .

During operation, the driving mechanism drives the eccentric shaft 60 to rotate, and the eccentric shaft 60 drives the tappet 30 up and down through the cooperation with the hole 32, which is not only simple in structure, easy to implement, but also safe and reliable in operation.

As shown in FIG. 5, the shaft body of the eccentric shaft 60 has a cylindrical shape, and the cylindrical shaft body is provided with an eccentric wheel 61 matched with the hole 32, and the eccentric wheel 61 is externally disposed. The diameter coincides with the inner diameter of the hole 32.

Referring to Figure 6 and in conjunction with Figure 1, the drive mechanism also has various implementations. The drive mechanism of the present invention includes a worm gear 71 that is fixedly sleeved on the eccentric shaft 60. The side of the worm gear 71 is disposed to cooperate with it. The worm 72, one end of the worm 72 is provided with a motor 73 for driving its rotation.

Further, the worm wheel 71 is provided with an angular position sensor, and the angular position sensor is electrically connected to the computer control unit ECU, and the computer control unit ECU is electrically connected to the motor 73. The worm gear 71 is connected to the eccentric shaft 60, and the motor 73 is a stepping motor.

The operation process of the present invention will be further described in detail below with reference to FIGS. 1 to 6:

The camshaft 10 is mounted above the cylinder head of the engine, and the tappet 30 is mounted in a pilot bore of the engine head, and the eccentric shaft 60 extends through the intermediate mounting bore 32 of the tappet 30. A finger type rocker arm 20 is attached to the upper end of the tappet 30, and a fulcrum of the finger type rocker arm 20 is a convex portion 31 provided at the top end of the tappet 30. The valve 40 is provided with a return spring 50 which functions to return and store energy. A worm wheel 71 is mounted at one end of the eccentric shaft 60. The worm wheel 71 and the eccentric shaft 60 are connected by a key. The worm wheel 71 is mounted with an angular position sensor for monitoring the deflection angle of the eccentric shaft 60 with respect to the reference position. The worm gear 71 and the worm 72 directly constitute a pair of cogwheel drive pairs. The stepping motor 73 can control the rotation of the worm 72, and the worm wheel 71 and the worm 72 cooperate to rotate the eccentric shaft 60, thereby realizing the up and down adjustment of the position of the tappet 30. When the operating condition of the engine requires a minimum valve lift, the computer control unit ECU monitors the relevant data and sends the command to the stepping motor 73. The stepping motor 73 operates to drive the worm 72 to rotate, and the worm gear 71 and the worm 72 cooperate. The motion is transmitted as a rotational motion of the eccentric shaft 60, and the eccentric shaft 60 causes the tappet 30 to move downward, as shown in FIG. When the camshaft 10 rotates, the lift of the cam 11 is transmitted to the finger rocker arm 20, because the lower side of the finger rocker arm 20 is provided with the tappet 30, and part of the column of the tappet 30 is spring-shaped due to The stiffness of the spring-like cylinder is less than the stiffness of the compression spring 50, so the cam 11 will travel an empty lift to achieve the compression stroke of the spring-like cylinder of the tappet 30 until the spring-like cylinder of the tappet 30 cannot be Compression, then the finger rocker 20 transmits the lift of the cam 11 to the valve 40, at which time the valve train has a minimum valve lift.

When the operating condition of the engine requires the maximum valve lift, the computer control unit ECU monitors the relevant data and sends the command to the stepping motor 73, which finally drives the rotary motion of the eccentric shaft 60, and the eccentric shaft 60 drives the tappet 30 up. At this time, the compression stroke of the spring-like cylinder of the tappet 30 will be reduced, as shown in FIG. At this time, the finger type rocker arm 20 acts on the tappet 30 under the pressure of the cam 11, until the spring-like column of the tappet 30 has been compressed and looped, and can no longer be compressed, and then the finger type rocker arm 20 presses the valve. The 40 is moved down so that the lift of the cam 11 is transmitted to the valve 40 through the finger rocker arm 20. Since the compression stroke of the tappet 30 is small during this process, the lift of the cam 11 is more converted into the lift of the valve 40, thereby maximizing the lift of the valve.

When the operating condition of the engine requires a moderate valve lift, only the stepping motor 73 is needed to adjust the eccentricity of the eccentric 61 to adjust the position of the tappet 30, thereby achieving the adjustability of the valve 40 lift. . In the present invention, the deflection angle of the eccentric 61 is set to 180 degrees, so that very precise adjustment precision can be ensured.

When the engine is under partial load conditions. The requirement to control the amount of intake air in the cylinder can be achieved by adjusting the deflection angle of the eccentric 61. At this time, the throttle valve can be fully opened, so that the interception loss under partial load is greatly reduced. The throttle-free operating condition not only improves the fuel economy of the engine, but also improves the idle stability and low-end torque with the traditional variable valve timing mechanism.

It should be noted that the above embodiments are only intended to illustrate the invention and are not to be construed as limiting the scope of the invention. The spirit and scope of the invention are intended to be included within the scope of the appended claims.

Claims

Claim

1. An engine valve train having an adjustable valve lift, comprising a cam (11) disposed on a camshaft (10), wherein: a lower side of the cam (11) is provided with a finger rocker (20), the cam (11) abuts against the bearing disposed on the finger rocker arm (20) and constitutes a rotary fit, and the lower side of one end of the finger type rocker arm (20) is provided with a position adjustable up and down The column (30) is provided with a valve (40) on the lower side of the other end, and the finger type rocker arm (20) is rotatable around its mating portion with the tappet (30), and the valve body of the valve (40) is sleeved. There is a return spring (50).

2. The valve valve with adjustable valve lift according to claim 1, wherein: the top of the tappet (30) is provided with a convex portion (31), and the finger type rocker arm (20) The bottom end surface is provided with a concave portion (21) fitted to the convex portion (31), and the finger type rocker arm (20) is rotatable around the fitting portion of the convex portion (31) and the concave portion (21). .

3. The valve valve with adjustable valve lift according to claim 2, wherein: part of the column of the tappet (30) is spring-like, and the stiffness of the spring-like column is less than The stiffness of the return spring (50).

4. The valve valve with adjustable valve lift according to claim 3, wherein: the upper side of the tappet (30) is spring-shaped, and the lower side of the tappet (30) is disposed. An eccentric shaft (60) is bored through the hole (32) of the column body, and one side of the eccentric shaft (60) is provided with a driving mechanism for driving the rotation thereof.

5. The valve valve with adjustable valve lift according to claim 4, wherein: said driving mechanism comprises a worm wheel (71) fixedly sleeved on the eccentric shaft (60), the worm wheel (71) The side is provided with a worm (72) that cooperates with one end, and one end of the worm (72) is provided with a motor (73) that drives its rotation.

6. The valve valve with adjustable valve lift according to claim 5, wherein: the shaft body of the eccentric shaft (60) has a cylindrical shape, and the cylindrical shaft body is provided with a hook body. The hole (32) is matched with an eccentric (61), and the outer diameter of the eccentric (61) coincides with the inner diameter of the hole (32).

7. The valve valve with adjustable valve lift according to claim 5, wherein: the worm wheel (71) is provided with an angular position sensor.

8. The valve valve with adjustable valve lift according to claim 5, wherein: the worm wheel (71) and the eccentric shaft (60) are keyed.

9. The valve valve with adjustable valve lift according to claim 5, wherein: said motor (73) is a stepping motor.

10. The valve valve with adjustable valve lift according to claim 7, wherein: the angular position sensor is electrically connected to a computer control unit, and the computer control unit is electrically connected to the motor (73). .