CN113007421A

CN113007421A - Gasoline engine EGR lift valve and opening and closing method

Info

Publication number: CN113007421A
Application number: CN202110387390.2A
Authority: CN
Inventors: 景建周; 杨晓明; 刘琦
Original assignee: Weinan Meilianqiao Automobile New Technology Research Institute Co ltd
Current assignee: Weinan Meiyite Engine Emission Reduction Technology Co ltd
Priority date: 2021-04-12
Filing date: 2021-04-12
Publication date: 2021-06-22

Abstract

The invention relates to a gasoline engine EGR poppet valve and an opening and closing method, comprising the following steps: valve body and valve gap, the valve body on be equipped with the disk seat, with the valve clack of disk seat cooperation switching and drive valve clack be linear motion's valve rod fixed connection, valve rod and the guide block sliding connection who drives valve rod motion, the guide block be linear motion's guide rail sliding connection with the restraint guide block, guide block and rotation axis fixed connection, the rotation axis on be equipped with antifriction bearing, antifriction bearing slide in Archimedes spiral groove, Archimedes spiral groove inlay in driven gear, driven gear and the driving gear meshing that is driven by the motor. The gear wheel arm is provided with the Archimedes spiral line groove, the rotary motion of the motor is converted into the linear motion of the opening and closing of the valve clack, and the speed reducing mechanism and the motion conversion mechanism are integrated, so that the volumes of the two mechanisms are greatly reduced, the opening and closing of the valve clack are more stable, stable and reliable, and the energy-saving and emission-reducing effects of the EGR system are improved.

Description

Gasoline engine EGR lift valve and opening and closing method

Technical Field

The invention relates to an EGR poppet valve of a gasoline engine and a method for opening and closing the EGR poppet valve, which are accessories of an automobile engine and are an electric valve for EGR circulation and a method for opening and closing the EGR poppet valve for environmental protection.

Background

In an engine exhaust gas recirculation system, an EGR poppet valve of a gasoline engine is mainly used for regulating and controlling the flow of recirculated exhaust gas. The GER lift valve of the gasoline engine controls the opening of an air inlet through an internal direct current motor, a sensor and an actuating mechanism to adjust the exhaust gas flow of the engine, so that the exhaust gas and fresh air are mixed according to a certain proportion and then return to an air cylinder for recirculation, the combustion temperature and the combustion speed in the air cylinder are reduced, and NO is further reduced_xThe amount of discharge of (c). With the stricter and stricter requirements on the emission control of the locomotive, the requirements on the control precision, the opening and closing response time and the working stability of the EGR valve are higher and higher; however, the EGR poppet valve of the existing gasoline engine has low relative control precision, slow response time and poor working stability, and cannot meet the increasingly strict use requirements. How to improve the existing poppet valve is a problem to be solved.

Disclosure of Invention

In order to overcome the problems of the prior art, the invention provides an EGR poppet valve of a gasoline engine and an opening and closing method. The lifting valve and the opening and closing method improve the control precision, accelerate the corresponding time and improve the working stability by the measures of arranging the Archimedes spiral in the spoke of the gear, accurately arranging the position of the sensor and the like.

The purpose of the invention is realized as follows: a gasoline engine EGR poppet valve comprising: valve body and valve gap, the valve body on be equipped with the disk seat, with the valve clack of disk seat cooperation switching and drive valve clack be linear motion's valve rod fixed connection, valve rod and the guide block sliding connection who drives valve rod motion, the guide block be linear motion's guide rail sliding connection with the restraint guide block, guide block and rotation axis fixed connection, the rotation axis on be equipped with antifriction bearing, antifriction bearing slide in Archimedes spiral groove, Archimedes spiral groove inlay in driven gear, driven gear and the driving gear meshing that is driven by the motor.

Furthermore, the guide block is of a concave structure, and the rotating shaft is arranged at a concave gap.

Furthermore, the driving gear and the driven gear are cylindrical involute spur gears.

Further, the bearing is one of a needle bearing, a deep groove bearing and a cylindrical roller bearing.

Furthermore, a position sensor is arranged on the guide block.

Furthermore, the position sensor is a magnet assembly fixed on the guide block and a Hall element fixed on the valve cover.

Furthermore, a return spring is arranged on the valve rod.

Furthermore, the contact surface of the valve clack and the valve seat is a spherical surface.

Further, the motor is a direct current motor.

A poppet valve opening and closing method using the above poppet valve, the method comprising the steps of:

poppet valve closing process: when the poppet valve is closed and started, the bearing is positioned at the far point of the Archimedes spiral groove, the valve clack and the valve seat are in the maximum separation state, and the return spring is in the compression state;

step 1, starting a motor to rotate to drive a driving gear to rotate, and driving the driving gear to drive a driven gear;

step 2, the Archimedes spiral groove rotates along with the driven gear to drive the bearing to gradually move from a far point to a near point of the Archimedes spiral groove;

step 3, because the bearing is restrained by the guide block and the guide rail thereof, the bearing can only do linear movement along the direction of the guide rail, so that the rotary motion of the driven gear is converted into the linear motion of the guide block;

step 4, the linear motion of the guide block pushes the linear motion of the valve rod, and the return spring is released;

step 5, the valve rod moves linearly to drive the valve clack to move towards the valve seat until the valve clack is closely combined with the valve seat, and the valve is closed;

the starting process of the lifting valve is as follows: when the lifting valve is started, the bearing is positioned at the near point of the Archimedes spiral groove, the valve clack and the valve seat are in a combined state, and the return spring is in a pre-compression state;

step 6, starting the motor to rotate to drive the driving gear to rotate, and driving the driving gear to drive the driven gear;

step 7, the Archimedes spiral groove rotates along with the driven gear to drive the bearing to gradually move from a near point to a far point of the Archimedes spiral groove;

step 8, because the bearing is restrained by the guide block and the guide rail thereof, the bearing can only do linear movement along the direction of the guide rail, so that the rotary motion of the driven gear is converted into the linear motion of the guide block;

step 9, the linear motion of the guide block pushes the linear motion of the valve rod and compresses the return spring;

step 10, the valve rod moves linearly to drive the valve clack to separate from the valve seat until the valve clack is in a fully opened state, and the valve is opened;

in the process that valve clack and disk seat combine or separate, the motor can shut down at any time, makes to maintain the clearance between valve clack and the disk seat, promptly: the valve is in a half-open-close state, and the size of a gap between the valve clack and the valve seat can be adjusted by starting and stopping the motor, so that the function of adjusting the flow is realized.

The invention has the advantages and beneficial effects that: the gear wheel arm is provided with the Archimedes spiral line groove, the rotary motion of the motor is converted into the linear motion of the opening and closing of the valve clack, and the speed reducing mechanism and the motion conversion mechanism are integrated, so that the volumes of the two mechanisms are greatly reduced, the opening and closing of the valve clack are more stable, stable and reliable, and the energy-saving and emission-reducing effects of the EGR system are improved.

Drawings

The invention is further illustrated by the following figures and examples.

FIG. 1 is a schematic diagram of a poppet valve according to one, six, seven, eight embodiments of the present invention;

FIG. 2 is a schematic view of a driven gear of a poppet valve according to one embodiment of the present invention, taken from A-A of FIG. 1;

fig. 3 is a cross-sectional view of a guide block having a concave shape according to a second embodiment of the present invention, which is an enlarged view of a point B in fig. 1.

Detailed Description

The first embodiment is as follows:

the embodiment is a gasoline engine EGR poppet valve, as shown in figures 1 and 2. The embodiment comprises the following steps: valve body 1 and valve gap 2, the valve body on be equipped with disk seat 3, with disk seat cooperation switching valve clack 4 and drive valve rod 5 fixed connection that linear motion is to the valve clack, valve rod and the guide block 6 sliding connection who drives the valve rod motion, the guide block with restrain the guide block and be linear motion's guide rail sliding connection, guide block and rotation axis 7 fixed connection, the rotation axis on be equipped with antifriction bearing 8, antifriction bearing slide in Archimedes spiral groove 901, Archimedes spiral groove inlay in driven gear 9, driven gear and the driving gear meshing that is driven by motor 10.

In this embodiment, the valve flap is opened and closed by linear motion, so that the rotational motion of the motor needs to be decelerated and converted into linear motion. Conventional poppet valves generally employ a cam mechanism, a spiral, or the like to convert rotation into linear motion. These shifting mechanisms are usually completely separate from the speed reduction mechanism, and the poppet valves thus configured are bulky and are very limited in installation in such a narrow space as an engine room. To solve this problem, this embodiment adopts a more special mechanism: the Archimedes spiral groove is arranged on the driven gear spoke with larger diameter, the linear distance between the spiral groove and the gear shaft is changed in the rotating process of the driven gear, and the transformation from rotation to linearity is realized by the constraint of the guide block and the guide rail, and meanwhile, the rolling bearing is arranged between the guide block and the spiral groove, so that the friction force between the guide block and the spiral groove is greatly reduced. The structure has the advantages that the speed reducing mechanism and the transformation mechanism are integrated, the structure is very compact, and the structure is very suitable for the requirement that the volume of the gasoline engine accessory is reduced as much as possible.

When the poppet valve works, the motor is electrified, the driving gear rotates along with the output shaft of the motor, the driving gear is meshed with the driven gear, the driven gear rotates to drive the bearing embedded in the Archimedes spiral groove to move, the bearing drives the guide block to move and the valve rod to move, the return spring is compressed, and when the valve clack is in the maximum separation state from the valve seat, the valve clack is kept in the maximum separation state by utilizing a duty ratio control technology, namely the valve is in an opening state; in the process of the movement and the stop of the valve clack, the relative position of the sensor and the magnet assembly changes, the opening degree of the poppet valve is controlled through a duty ratio control technology according to a signal sent by an engine ECU, and the circulating air inflow is finally controlled. When power is cut off, the output shaft of the motor does not have power, the return spring restores the original state in advance, elastic force is generated to enable the bearing to press the Archimedes spiral groove of the driven gear, the Archimedes spiral groove and the bearing are arranged in a biased mode, the driven gear rotates, the poppet valve is closed, namely when power is cut off, the poppet valve is in a closed state, and the power-cut self-resetting function of the poppet valve is achieved.

The guide block in this embodiment may have various forms, for example, a concave shape in which a concave portion passes through a rim of the gear, an L shape, or the like. The guide block is in contact with the spiral groove by using a rolling bearing. The rolling bearing may be a needle bearing, or a cylindrical roller bearing, or a deep groove bearing, or the like.

The motor power transmission in the embodiment adopts involute gears such as cylindrical straight gears or cylindrical helical gears, and can also adopt worm and gear transmission. The drive gear may be mounted directly on the motor shaft or coupled to the motor shaft via a coupling. To obtain a larger speed ratio and a larger spoke space, the diameter of the driven gear can be larger. It should be noted that the archimedes 'spiral in this embodiment is a planar spiral, rather than a solid spiral, and therefore the archimedes' spiral groove is generally tiled in the spoke plane of the driven gear.

The valve body valve gap is bearing structure, and all parts are all installed on valve body and valve gap. The valve body and the valve cover are fixedly connected through bolts. The valve body and the valve cover can be cast or machined by cast iron or other alloy materials.

The valve clack and the valve clack are key parts for opening and closing the valve, the valve seat is fixed on the valve body, and the valve clack is driven by the valve rod to generate the action of closing or separating from the valve seat. The position where the valve seat and the valve clack are matched can be designed to be a plane, a conical surface or a spherical surface.

To determine the position of opening and closing of the valve flap, a position sensor may be provided on the guide block to determine the position of the valve stem and the valve flap integrated with the positioning block. The sensor may be a hall element, an electromagnetic induction element, or the like.

The motor can adopt an alternating current motor or a direct current motor, wherein the direct current motor has large transmission torque and strong overload capacity and is more suitable for the opening and closing action of the valve.

Example two:

this embodiment is an improvement of the first embodiment, and is a refinement of the first embodiment with respect to the guide block. The guide block of this embodiment is a concave structure, and the rotating shaft is disposed at the notch of the concave structure, as shown in fig. 3.

The concave notch of the embodiment is inserted into the rim of the driven gear, so that the rotating shaft can enter the Archimedes spiral groove. Because the rotating shaft and the concave-shaped gap form a simple supporting beam, the stress condition is good.

Example three:

this embodiment is a modification of the above embodiment, and is a refinement of the above embodiment with respect to the gear. The driving gear and the driven gear are cylindrical involute spur gears.

The opening and closing of the EGR valve usually needs a short time, so the reduction ratio of the speed reducer cannot be too large, the worm and gear are not suitable, the cylindrical gear can be adopted, and when a proper speed ratio is needed, the diameter of the driven gear is required to be larger.

Example four:

this embodiment is a modification of the above embodiment, and is a refinement of the above embodiment with respect to the bearing. The bearing described in this embodiment is one of a needle bearing, a deep groove bearing, and a cylindrical roller bearing.

Because the width of the spiral groove is limited to a certain extent, the diameter of an outer ring of the bearing is also limited, the rolling needle with a smaller rolling body is suitable, and the deep groove bearing is more in variety and model and easy to find a suitable model, so that the deep groove bearing has certain advantages.

Example five:

this embodiment is a modification of the above-described embodiment, and is a refinement of the above-described embodiment with respect to the guide block. The guide block described in this embodiment is provided with a position sensor.

During engine operation, the ECU needs to know the open and closed state of the poppet valve. For this purpose the poppet valve can signal the open or closed state of the flap in various ways. In the embodiment, a sensor is arranged on the guide block which makes the valve rod do the same linear motion and is used for determining the position of the valve rod so as to determine whether the valve clack is opened or closed. The sensor can adopt various sensors capable of determining positions, such as a Hall element, an electromagnetic induction element or an optical coupler.

Example six:

the present embodiment is a modification of the above-described embodiment, and is a refinement of the above-described embodiment with respect to the position sensor. The position sensor described in this embodiment is a magnet assembly 601 fixed to the guide block and a hall element 602 fixed to the valve cover, as shown in fig. 1.

A hall element is a common electromagnetic induction element and needs to be matched with a magnet having relative motion. The magnet is arranged on the moving guide block, and the Hall element is fixed on the valve cover to realize the mutual movement of the magnet and the valve cover.

Example seven:

this embodiment is a modification of the above-described embodiment, and is a refinement of the above-described embodiment with respect to the valve stem. The valve rod of this embodiment is provided with a return spring 501, as shown in fig. 1.

The function of the return spring is to make the valve rod in the state of moving towards the opening direction, and maintain the state of tensioning the valve rod, and eliminate the clearance between the spiral groove and the bearing.

Example eight:

this embodiment is a modification of the above embodiment, and is a refinement of the above embodiment with respect to the gear. The contact surface between the valve flap and the valve seat in this embodiment is a spherical surface 401, as shown in fig. 1.

The contact of the conical surface is adopted between the valve clack and the valve seat in the embodiment, and the contact of the conical surface is changed into the spherical surface contact, so that the adhesion prevention effect can be better generated.

Example nine:

the present embodiment is a modification of the above-described embodiments, and is a refinement of the above-described embodiments with respect to the motor. The motor described in this embodiment is a dc motor.

The starting torsion of the direct current motor is large, and the problem that the valve clack cannot be opened when being adhered to the valve seat can be well solved.

Example ten:

the present embodiment is a poppet valve opening and closing method using the above poppet valve. The basic mode of this embodiment is to use a wider spoke of the driven gear to provide an archimedes spiral groove, to use it as a cam, and to convert the rotary motion of the motor into linear motion by the sliding of the bearing in the archimedes spiral groove, and to push the valve rod and the valve flap to open and close.

The method comprises the following specific steps:

poppet valve closing process: when the poppet valve is closed and started, the bearing is positioned at the far point of the Archimedes spiral groove, the valve clack and the valve seat are in the maximum separation state, and the return spring is in the compression state.

It should be noted that the "far point" and "near point" of the archimedes spiral groove in the present embodiment refer to the distance between the two end points of the spiral groove and the central axis of the driven gear. The farther from the driven gear central axis is the "far point", and the closer to the driven gear central axis is the "near point".

The "closing process" refers to a process in which the valve flap of the poppet valve changes from a fully open state to a fully closed state. This process of fully opening to fully closing is for descriptive convenience and is also adapted to the process of movement of the flap toward closing in the semi-open and semi-closed condition. Similarly, the following "opening procedure" is equally applicable.

Step 1, a motor is started to rotate to drive a driving gear to rotate, and the driving gear drives a driven gear.

The step is a deceleration process, and the high-speed rotation of the motor is reduced to low-speed rotation.

And 2, the Archimedes spiral groove rotates along with the driven gear to drive the bearing to gradually move from a far point to a near point of the Archimedes spiral groove.

The bearing is arranged in the Archimedes spiral groove, moves along with the spiral groove, rolls in the spiral groove and moves from the far point end to the near point end of the groove.

And 3, because the bearing is constrained by the guide block and the guide rail thereof and can only move linearly along the direction of the guide rail, the rotary motion of the driven gear is converted into the linear motion of the guide block.

The driven gear rotates to drive the bearing to move along the Archimedes spiral groove, and the bearing is mounted on the guide block, and the guide block is constrained by the guide rail, so that the bearing can only move along the guide rail under the constraint of the Archimedes spiral groove, and the movement of the bearing in the Archimedes spiral groove is converted from rotation to linear movement.

And 4, pushing the linear motion of the valve rod by the linear motion of the guide block, and releasing the return spring.

The movement of the guide block drives the valve stem and the movement of the valve flap to form a closing action.

And 5, the valve rod moves linearly to drive the valve clack to move towards the valve seat until the valve clack is closely combined with the valve seat, and the valve is closed.

The following steps are the reverse direction of the above steps 1-5.

The starting process of the lifting valve is as follows: when the lifting valve is started, the bearing is positioned at the near point of the Archimedes spiral groove, the valve clack and the valve seat are in a combined state, and the return spring is in a pre-compression state.

The pre-compressed state means that the return spring is in a relaxed state, but not completely relaxed, but maintained at a certain tension.

Finally, it should be noted that the above is only intended to illustrate the technical solution of the present invention and not to limit it, and although the present invention has been described in detail with reference to preferred arrangements, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made to the technical solution of the present invention (such as the form of the flap, the form of the flap opening, the sequence of steps, etc.) without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A gasoline engine EGR poppet valve comprising: valve body and valve gap, the valve body on be equipped with the disk seat, with the valve clack of disk seat cooperation switching and drive valve clack be linear motion's valve rod fixed connection, valve rod and the guide block sliding connection who drives the valve rod motion, its characterized in that, guide block and restraint guide block be linear motion's guide rail sliding connection, guide block and rotation axis fixed connection, the rotation axis on be equipped with antifriction bearing, antifriction bearing slide in Archimedes spiral groove, Archimedes spiral groove inlay in driven gear, driven gear and the driving gear meshing that drives by the motor.

2. The poppet valve as defined in claim 1, wherein the guide block has a recessed configuration, and the rotary shaft is disposed at a recess of the recessed configuration.

3. The poppet valve of claim 2, wherein the drive gear and the driven gear are spur involute cylindrical gears.

4. The poppet valve of claim 3, wherein the bearing is one of a needle bearing, a deep groove bearing, and a cylindrical roller bearing.

5. The poppet valve as defined in claim 4, wherein the guide block is provided with a position sensor.

6. The poppet valve of claim 5, wherein the position sensor is a magnet assembly secured to the guide block and a hall element secured to the valve cover.

7. The poppet valve as defined in claim 6, wherein the valve stem is provided with a return spring.

8. The poppet valve as defined in claim 7, wherein the valve flap has a spherical surface contacting the valve seat.

9. The poppet valve of claim 8, wherein the motor is a dc motor.

10. A method of opening and closing a poppet valve using the poppet valve of claim 9, comprising the steps of: