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CN-121993325-A - EGR valve

CN121993325ACN 121993325 ACN121993325 ACN 121993325ACN-121993325-A

Abstract

The invention provides an EGR valve, which comprises a driving motor, a driving gear, a driven gear, a reciprocating unit and a shell, wherein the driving gear is combined with a motor shaft of the driving motor, the driven gear is connected with the driving gear, the reciprocating unit is used for opening or closing an exhaust gas flow path through reciprocating along a first direction, the first direction is a direction crossing a rotating shaft of the driven gear, the shell is used for accommodating the driving motor, the driving gear, the driven gear and the reciprocating unit and forming an exhaust gas flow path, the driven gear comprises a gear part, a tooth shape is formed on the outer peripheral surface of a gear body, the tooth shape is meshed with the driving gear, and a cam part is integrally formed with the gear part and shares the rotating shaft with the gear part, and at least one part of the reciprocating unit is contacted with a cam contact surface of the cam part, so that linear motion is carried out along with the rotating motion of the driven gear.

Inventors

  • LI ZONGZHU
  • JIN ZHENYONG

Assignees

  • 株式会社科伦斯

Dates

Publication Date
20260508
Application Date
20250305
Priority Date
20241106

Claims (16)

  1. 1. An EGR valve, comprising: A driving motor; a driving gear coupled to a motor shaft of the driving motor; A driven gear connected to the drive gear; A reciprocating unit that opens or closes an exhaust gas flow path by being arranged in a first direction that is a direction intersecting a rotation axis of the driven gear and being reciprocally moved in the first direction, and A housing that accommodates the driving motor, the driving gear, the driven gear, and the reciprocating unit, and forms an exhaust gas flow path, Wherein, driven gear includes: a gear part in which a tooth form is formed on an outer peripheral surface of the gear body, the tooth form being engaged with the drive gear, and A cam portion integrally formed with the gear portion and sharing the rotation shaft with the gear portion, Wherein at least a part of the reciprocating unit is in contact with a cam contact surface of the cam portion, thereby performing a linear motion with a rotational motion of the driven gear.
  2. 2. The EGR valve of claim 1 wherein, The central axis corresponding to the longitudinal direction of the reciprocating unit is perpendicular to the rotation axis of the driven gear.
  3. 3. The EGR valve of claim 1 wherein, The cam portion is formed protruding from the gear body in an axial direction of the rotation shaft, and is formed such that the cam contact surface is parallel to the rotation shaft.
  4. 4. The EGR valve of claim 1 wherein, The cam portion forms a helical cam profile, In the cam portion, as the rotation angle of the cam portion increases, the distance from the rotation center to the cam contact surface increases.
  5. 5. The EGR valve of claim 4 wherein, The cam profile is expressed in x, y coordinates and is determined by x= Rcos θ+ (2πrθ/360 ° +a) sin θ, y= Rsin θ - (2ρrθ/360 ° +a) cos θ, And satisfies the conditions of a=offset value, r=base circle radius, 0 degree or more and θ degree or less and 360 degrees or less.
  6. 6. The EGR valve of claim 1 wherein, The reciprocating unit includes: A follower in contact with the cam contact surface of the cam portion; a valve head that opens or closes the exhaust gas inflow port; A valve shaft provided with the valve head at one end; a connecting portion connecting the follower and the other end portion of the valve shaft, and And a slide pin fixed to the connection portion and arranged in parallel with a rotation axis of the driven gear.
  7. 7. The EGR valve of claim 6 wherein, The rotation shaft of the driven gear and the sliding pin are arranged on an extension line of the valve shaft.
  8. 8. The EGR valve of claim 6 wherein, The slide pin is inserted into the center of the follower.
  9. 9. The EGR valve of claim 6 wherein, The driven gear further includes a guide portion formed on the gear body, The guide portion includes a guide groove into which at least a portion of the slide pin is inserted.
  10. 10. The EGR valve of claim 9 wherein, The guide portion is formed adjacent to the cam contact surface and is formed in a shape corresponding to the cam contact surface.
  11. 11. The EGR valve of claim 9 wherein, When the driven gear rotates, the guide portion moves relative to the slide pin in a state where the slide pin is inserted into the guide groove.
  12. 12. The EGR valve of claim 9 wherein, The slide pin restricts a rotation range of the driven gear by interfering with one end or the other end of the guide groove.
  13. 13. The EGR valve of claim 9 wherein, The guide groove is an inner space surrounded by a guide wall formed to protrude from the gear body in the axial direction of the rotary shaft.
  14. 14. The EGR valve of claim 1 wherein, The EGR valve includes: a first elastic member provided on a surface opposite to one surface of the gear body on which the cam portion is formed, and And a second elastic member provided to the reciprocating unit.
  15. 15. The EGR valve of claim 14 wherein, When the rotation direction of the driven gear that lowers the reciprocating unit is defined as a second direction, The first elastic member provides an elastic force to the driven gear to rotate the driven gear in a direction opposite to the second direction.
  16. 16. The EGR valve of claim 14 wherein, The second elastic member provides an elastic force to the reciprocating unit to move the reciprocating unit toward the rotation shaft of the driven gear.

Description

EGR valve Technical Field The present invention relates to an EGR valve. Background Generally, an automobile engine encloses a mixture of fuel and air in a sealed cylinder, and rapidly burns carbon in the fuel by compression and ignition. The burned gas is discharged to the outside, and this gas discharged to the outside is called exhaust gas. Most of the components of the exhaust gas are steam and carbon dioxide, and the remaining components of the exhaust gas include harmful substances such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). An exhaust gas recirculation system (Exhaust Gas Recirculation System, EGR) is configured to reduce the amount of nitrogen oxides (NOx) produced by returning a portion of the exhaust gas to the intake manifold and reducing the combustion temperature when the mixture is continuous. The EGR system includes an EGR valve, which functions to add a part of the exhaust gas to the mixer by controlling the EGR valve, thereby causing the part of the exhaust gas to enter the cylinder. The EGR valve includes a housing on which an inflow port and an exhaust port are formed, an opening and closing unit that selectively opens and closes the inflow port, and a driving unit that operates the opening and closing unit. Since the inlet port of the housing is connected to the exhaust manifold of the engine and the outlet port is connected to the intake manifold of the engine, a part of exhaust gas discharged from the exhaust manifold is selectively moved to the intake manifold by the EGR valve according to the operation of the driving unit and the opening/closing unit. The existing EGR valve includes a poppet shaft, which is a part of an opening and closing unit and which performs up-and-down reciprocating motion, and a poppet valve, which is formed at a front end of the poppet shaft and opens and closes an inflow port and an exhaust port of exhaust gas. Further, the conventional EGR valve is equipped with an operation cam for reciprocating the lift valve shaft up and down, and when the rotational motion of the operation cam is converted into the up-and-down motion of the opening and closing unit, the driving force loss is large, so that a large capacity driving motor is required to obtain the required driving force. Further, the up-and-down movement of the valve unit according to the rotational movement of the operating cam is implemented in a non-linear manner, and thus it is difficult to control the opening degree of the valve unit. Disclosure of Invention Technical problem The present invention aims to solve the above-mentioned problems, and an object of the present invention is to provide an EGR valve which can achieve stabilization and optimization of mechanical kinetic energy transfer by an optimized cam profile. Technical proposal An embodiment of the present invention provides an EGR valve including a driving motor, a driving gear coupled to a motor shaft of the driving motor, a driven gear connected to the driving gear, a reciprocating unit opening or closing an exhaust gas flow path by being disposed in a first direction and being reciprocally moved in the first direction, the first direction being a direction crossing a rotation axis of the driven gear, and a housing accommodating the driving motor, the driving gear, the driven gear, and the reciprocating unit and forming an exhaust gas flow path, wherein the driven gear includes a gear portion in which a tooth shape is formed on an outer circumferential surface of a gear body, the tooth shape being engaged with the driving gear, and a cam portion formed integrally with the gear portion and sharing the rotation axis with the gear portion, wherein at least a portion of the reciprocating unit is in contact with a cam contact surface of the cam portion, thereby performing a linear motion with a rotational motion of the driven gear. In an embodiment of the present invention, a central axis corresponding to a longitudinal direction of the reciprocating unit may be perpendicular to a rotation axis of the driven gear. In an embodiment of the present invention, the cam portion may be formed to protrude from the gear body in an axial direction of the rotation shaft, and may be formed such that the cam contact surface is parallel to the rotation shaft. In an embodiment of the present invention, the cam portion may form a spiral cam profile in which a distance from a rotation center to the cam contact surface may increase as a rotation angle of the cam portion increases. In one embodiment of the invention, the cam profile can be expressed in x, y coordinates, And is determined by x=rcoθ+ (2pi rθ/360 ° +a) sin θ, y=rcinθ - (2pi rθ/360 ° +a) cos θ, And the conditions of a=offset value, r=base circle radius, θ being 0 degree or more and 360 degrees or less can be satisfied. In an embodiment of the present invention, the reciprocating unit may include a follower in contact with the cam contact surface of the cam portion, a