KR101604413B1 - Egr valve - Google Patents

Abstract

The EGR valve is started. The EGR valve includes a housing; An opening and closing unit installed in the housing with a poppet shaft and a poppet disposed at a front end of the poppet shaft, the opening and closing unit opening and closing the exhaust gas channel by the upward and downward movement of the poppet; And a driving unit that is installed in the housing and drives the poppet shaft up and down to move the poppet up and down. The driving unit includes a cam driving unit that receives the rotational force through the intermediate gears and moves the poppet shaft up and down Wherein the cam driving unit includes a cam-driven driven gear which is integrally formed with a cam portion and a gear shaft having a cam hole and rotates while partially meshing with an intermediate gear of the intermediate gears, and a roller coupled with the poppet shaft, And a roller which moves along the cam hole while being installed on the roller plate.

Description

EGR valve {EGR VALVE}

The present invention relates to an EGR valve, and more particularly, to an EGR valve that assembles a plate provided with a roller at one end of a poppet shaft and provides a component incorporating a function of a cam interacting with a roller and a function of a half- The present invention relates to an EGR valve that reduces the number of parts, the number of assembling processes, and the manufacturing cost by allowing the parts to have a shaft integrally. Further, the present invention relates to an EGR valve in which a roller plate provided with a roller at one end of a poppet shaft is assembled by welding, and the strength is enhanced by an improved welding structure of a roller plate and a poppet shaft.

Generally, an engine of an automobile confines a mixture of fuel and air in a closed cylinder, compresses and ignites, and burns carbon in the fuel rapidly. The gas after combustion is discharged to the outside, and the gas discharged to the outside is used as the exhaust gas. Water vapor and carbon dioxide constitute most of the exhaust gas, and the exhaust gas contains harmful substances such as carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx).

An exhaust gas recirculation system (EGR) system is configured to reduce the amount of nitrogen oxides (NOx) generated by returning a part of the exhaust gas to the intake manifold to decrease the combustion temperature when the mixer is continued. The EGR system includes an EGR valve, through which part of the exhaust gas is added to the mixer and sucked into the cylinder.

The EGR valve includes a housing having an inlet and an outlet, an opening / closing unit for selectively opening and closing the inlet, and a drive unit for operating the opening / closing unit. The intake port of the housing is connected to the exhaust manifold of the engine and the exhaust port is connected to the intake manifold of the engine so that a part of the exhaust gas discharged from the exhaust manifold according to the operation of the drive unit and the opening / And selectively moves to the intake manifold. BACKGROUND ART [0002] Conventional EGR valves include a poppet shaft that reciprocates up and down as a part of an opening / closing unit, and a poppet that is formed at the tip of the poppet shaft and opens and closes an intake port and an exhaust port of the exhaust gas. Further, the EGR valve includes a cam plate coupled to the base end of the poppet shaft as a part of the drive unit, and the cam plate is provided with a cam hole through which the roller is guided. The cam plate has a pair of legs, and the cam plate and the poppet shaft are butt welded and joined together with the poppet shaft inserted between the pair of legs. Further, the driving unit of the conventional EGR valve includes a gear train connected to the motor, and a half-moon gear is provided at the final stage of the gear train. At this time, the shaft supporting the half-moon gear and the half-moon gear is assembled by welding.

The conventional EGR valve is disadvantageous in that the connection structure between the cam plate, the poppet shaft and the gear is complicated and weak. Particularly, the structure in which the poppet shaft is welded to a pair of legs provided on the cam plate greatly reduces the coupling strength between the cam plate and the poppet shaft, and the structure of the shaft and the roller is also complicated. There is a drawback that the welding operation is difficult. Further, the conventional EGR valve is disadvantageous in that the dimension stability of the welding assembly is poor, the number of parts is large, and the weight is large. In addition, the conventional EGR valve has a problem that noise is generated during operation.

Korean Patent Laid-Open No. 10-2009-0132804 (December 31, 2009)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a component incorporating a plate provided with a roller at one end of a poppet shaft and integrating the function of a cam interacting with the roller and the function of a half moon gear, The number of parts, the number of assembling steps and the manufacturing cost are reduced.

Another object of the present invention is to provide an EGR valve in which a roller plate having a roller at one end of a poppet shaft is assembled by welding, and the strength of the EGR valve is enhanced by an improved welding structure of a roller plate and a poppet shaft.

An EGR valve according to one aspect of the present invention includes: a housing; An opening / closing unit installed in the housing with a poppet shaft and a poppet disposed at a front end of the poppet shaft, the opening / closing unit opening / closing the exhaust gas flow path by vertically moving the poppet; And a drive unit installed in the housing and driving the poppet shaft up and down for up and down movement of the poppet. The drive unit receives a rotational force through intermediate gears and moves the poppet shaft up and down Wherein the cam driving unit includes a cam-driven driven gear which is integrally formed with a cam portion and a gear shaft having a cam hole and rotates while partially meshing with an intermediate gear of the intermediate gears, and a roller coupled with the poppet shaft, And a roller which moves along the cam hole while being installed on the roller plate.

According to one embodiment, the cam-attached driven gear includes a half-moon-shaped body portion having a toothed-shaped arc interlocking with one of the intermediate gears, and the cam portion and the gear shaft And is integrally formed on each of the front surface and the back surface of the half-moon body portion.

According to one embodiment, the poppet shaft includes a horizontal surface in the vicinity of the base end, and the poppet shaft is overlapped by the horizontal surface and the roller plate so as to contact the front surface or the back surface of the roller plate, Plate.

According to one embodiment, the housing includes a first gear mounting portion including an arcuate inner surface corresponding to a rotation locus of the cam-driven driven gear, and a second gear mounting portion corresponding to a rotation locus of the intermediate gear having the largest diameter among the intermediate gears A flange portion for connecting the flow path to be opened and closed by the poppet, and a second gear mounting portion formed to share a predetermined region with the first gear mounting portion in an intersecting manner, And a connecting portion formed to be gradually narrowed from the outer sheath contact of the mounting portion to the flange portion.

According to one embodiment, the housing includes a cooling channel partially surrounding the poppet center at the flange portion side, the cooling channel having a tangent to a virtual circle about the poppet center, And a second and a third line portion adjacent to both sides of the poppet center and intersecting the imaginary circle, each intersecting the first line portion at an angle of 90 degrees or more.

According to one embodiment, the poppet shaft includes a plurality of dimples continuously formed along the length direction.

The EGR valve according to the present invention is characterized in that a plate provided with a roller at one end of a poppet shaft is assembled and a component integrating the function of a cam interacting with the roller and the function of a semi- So that the number of parts, the number of assembling steps and the manufacturing cost are reduced.

In addition, the EGR valve according to the present invention is advantageous in that the roller plate having the roller at one end of the poppet shaft is assembled by welding, and the strength is improved by the improved welding structure of the roller plate and the poppet shaft.

Further, the EGR valve according to the present invention is advantageous in that the EGR valve is light in weight by the structure for optimizing the component placement of the housing and the gradual size reduction structure of the connection portion. Further, the EGR valve according to the present invention includes a configuration in which the poppet center and the cooling flow path can be arranged as close as possible to each other, and the cooling effect can be maximized by this configuration.

The EGR valve according to the present invention can prevent contaminants from flowing into the drive unit side by a plurality of dimples formed in the poppet shaft.

1 is a perspective view illustrating an EGR valve according to an embodiment of the present invention in a state in which a part of the housing is opened.
FIG. 2 is an exploded perspective view showing the main elements of the EGR valve according to the embodiment of the present invention in a state where the housing is omitted. FIG.
3 is a front view of the EGR valve according to the embodiment of the present invention in which the housing is omitted.
FIG. 4 is a perspective view showing a cam driving unit of the EGR valve shown in FIGS. 1 to 3. FIG.
FIG. 5 is a perspective view for explaining a coupling structure of the poppet shaft and the roller plate of the EGR valve shown in FIGS. 1 to 3. FIG.
FIG. 6 is a view for explaining the dimple structure of the poppet shaft applied to prevent the inflow of contaminants into the driving unit of the EGR valve shown in FIGS. 1 to 4. FIG.
FIGS. 7A and 7B are views for explaining a structure for optimizing and reducing parts of an EGR valve housing according to an embodiment of the present invention. FIG.
8 is a view for explaining a cooling flow path pattern of an EGR valve housing according to an embodiment of the present invention.
9 is a view for explaining an assembling structure of an EGR valve housing according to an embodiment of the present invention.
FIGS. 10A to 10C are views for explaining the prior art comparatively to the present invention. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The accompanying drawings and the description are intended to assist the reader in understanding the present invention. Accordingly, the drawings and description of the embodiments should not be construed as limiting the scope of the invention.

FIG. 1 is a perspective view illustrating an EGR valve according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating a main part of an EGR valve according to an embodiment of the present invention, 3 is a front view of the EGR valve according to the embodiment of the present invention in which the housing is omitted. FIG. 4 is a perspective view showing the cam driving unit of the EGR valve shown in FIGS. 1 to 3. FIG. And FIG. 5 is a perspective view for explaining a coupling structure of the poppet shaft and the roller plate of the EGR valve shown in FIGS. 1 to 3. FIG. 6 is a driving unit of the EGR valve shown in FIGS. FIGS. 7A and 7B are views for explaining the dimple structure of the poppet shaft applied to prevent the inflow, and FIGS. 7A and 7B are views for explaining the structure for optimizing and reducing the parts of the EGR valve housing according to the embodiment of the present invention FIG. 8 is a view for explaining a cooling flow path pattern of the EGR valve housing according to an embodiment of the present invention, and FIG. 9 is a view for explaining an assembling structure of the EGR valve housing according to the embodiment of the present invention. And Figs. 10A to 10C are views for explaining the prior art comparatively to the present invention.

1 to 9, an EGR valve 1 according to an embodiment of the present invention includes a housing 100, a driving unit and an opening / closing unit provided in the housing 100. The opening and closing unit includes a poppet shaft 410 and a poppet 420 installed at the tip of the poppet shaft 410 and substantially functioning to open and close the flow channel. Thereby opening and closing the flow path by reciprocating the poppet 420 up and down.

The EGR valve 1 includes a DC motor 210 and a cam driving unit 230, which constitute the driving unit. A first intermediate gear 222 that rotates in engagement with the main gear and a second intermediate gear 222 that rotates in conjunction with the main driving gear 230 and the cam driving unit 230 And a second intermediate gear 223 which partially engages with the driven gear 231 with the cam-side driven gear 231 and intermittently rotates the driven gear 231. The cam driving unit 230 converts the rotational power transmitted from the DC motor 210 into a reciprocating motion to drive the poppet shaft 410 and the poppet 420.

The cam drive unit 230 includes a cammed driven gear 231 that includes a half of the circle, more preferably a half-mound body 2310 from which approximately half is removed And includes a toothed tooth 2312 at the arc of the circular body 2310. Since the cam-driven driven gear 231 has a half-moon shape, it can be called a "half-moon gear". The cam-driven driven gear 231 integrally includes a cam portion 2313 having a cam hole 2314 formed on the front surface of the body portion 2310. A gear shaft 2314 is integrally provided on the back surface of the cam-driven driven gear 231. The cam-driven driven gear 231 is integrally formed with the body portion 2310, the tooth 2312, the cam portion 2313, and the gear shaft 2315 by injection molding.

As shown in Fig. 10A, the semicylindrical gear G is employed also in the drive unit of the conventional EGR valve. However, the semicircular gear of the conventional EGR valve is configured such that the cam portion is formed integrally with the cam formed on the cam plate P Since the structure in which the roller R is installed and the gear shaft is not integrally formed and is assembled with the gear shaft S made of stainless steel, there is a problem that the number of parts is larger than that of the driven gear with the cam of the EGR valve according to the present embodiment It is holding.

1 to 9, the cam driving unit 230 includes a roller plate 232 coupled to a base end (or an upper end) of the poppet shaft 410, And a roller 233 to be installed. The roller 233 is inserted into the cam hole 2314 formed in the cam-driven driven gear 231. Therefore, when the cam-driven driven gear 231 or the cam portion 2313 integral therewith rotates, the roller 233 moves along the inner surface of the cam hole 2314, that is, the cam surface. The movement of the roller 233 causes the poppet shaft 410 coupled with the roller plate 232 to move up and down so that the poppet 420 is also moved up and down to selectively open the exhaust gas inlet Thereby opening and closing. At this time, a position sensing magnet 234 is installed on one side of the roller plate 232.

The poppet shaft 410 includes a horizontal surface 412 formed by flattening a part of the outer circumferential surface near the base end. The poppet shaft 410 is overlapped by the overlapping welding between the horizontal surface 412 and the roller plate 232 after the horizontal surface 412 is overlapped with the front surface or the back surface of the roller plate 232, 232 in a more reliable and high-intensity manner. 10B, there is a structure in which a cam plate P and a poppet shaft M are welded to each other. This structure forms a pair of legs on the cam plate P and a pair of legs L, and L, the poppet shaft M is sandwiched and welded, and the weld strength is greatly reduced.

 1 to 9, when the DC motor 210 is driven, the main gear provided on the motor shaft of the DC motor 210 rotates, and meshing with the main gear to form the first intermediate gear 222 The second intermediate gear 223 of small diameter provided on the same axis as the first intermediate gear 222 rotates. The second intermediate gear 223 and the cam driven driven gear 231 engaged with the gear are rotated and the roller 233 is driven by the cam driven driven gear 231 The roller plate 232 on which the roller 233 is mounted and the poppet shaft 410 engaged with the roller plate 232 move up and down, As a result, the poppet 420 also moves up and down to selectively open and close the exhaust gas inlet. At this time, the cam-driven driven gear 231 has only a part of the circle formed in a half-moon shape, and a toothed tooth 2312 is formed only on a part of the outer circumferential surface thereof, which corresponds to the rotation locus of the cam.

The housing 100 includes a first gear installing portion 110 having an arc-shaped inner surface corresponding to a rotational locus of the cam-driven driven gear 231 and a center of the cam-driven driven gear 231, And a second gear installation part 120 located at the outer periphery of the first gear installation part 110 including an arc-shaped inner surface corresponding to the rotation locus of the first intermediate gear 222 having the largest diameter . The second gear installing portion 120 intersects a predetermined region with the first gear installing portion 110 in an intersecting manner. The housing 100 includes a flange portion 140 for connection with a flow path opened and closed by the poppet 420. The connection portion 130 is gradually converged (narrowed) from the outer contacts of the first gear installation portion 110 to the flange portion 140, and the connection portion 130 is formed in the connection portion 130, 410 are guided up and down. The size of the housing and the weight of the housing can be greatly reduced through the gradually narrowing shape of the connecting portion 130 and the optimization of the placement using the first and second gear installing portions 110 and 120 described above.

In addition, the housing 100 may be constructed by assembling the first and second housing parts 100a and 100b through bolts. The first housing part 100a includes a protruding bolting guide 1001 And the second housing part 1002 integrally includes a bolting part 1002 corresponding to the bolting guide 1001. Thereby, it is possible to delete the bush parts.

The housing 100 includes a cooling passage 101 that partially surrounds the poppet center C in three directions on the side of the flange portion 140. The cooling passage 101 is connected to the poppet center C, A first line portion 101a which coincides with a tangent to a virtual circle centered on the poppet center C and a second line portion 101b which is arranged at an angle of 90 degrees or more with respect to the first line portion 101a And second and third line portions 101b and 101c adjacent to both sides of the poppet center C to intersect with the imaginary circle. When the above-described design conditions are applied within the allowable range and the virtual diameter of the virtual circle is reduced to the maximum, the cooling flow path 101c composed of the first, second and third line portions 101a, 101b and 101c, The distance between the surrounding poppet center C can be minimized.

The pattern of the cooling passage described above can be greatly contributed to the improvement of the cooling performance of the poppet shaft passing the poppet center by reducing the distance from the poppet center as compared with the pattern of the conventional cooling channel as shown in Fig.

As best shown in FIG. 6, the poppet shaft 410 includes a plurality of dimples 415 formed continuously along the longitudinal direction. These dimples 415 are formed to minimize contaminants flowing into the drive unit side along the assembly clearance of the poppet and the poppet shaft.

100: housing 230: cam driving part
231: driven gear with cam 232: roller plate
233: roller 410; Poppet shaft
420: poppet 2313: cam portion
2314: Cam hole 2315: Gear shaft

Claims (6)

delete delete delete delete delete In the EGR valve,
housing;
An opening / closing unit installed in the housing with a poppet shaft arranged so that its longitudinal direction faces upward and downward and a poppet provided at the tip of the poppet shaft, the opening / closing unit opening / closing the exhaust gas flow path by the upward / downward movement of the poppet; And
And a drive unit installed in the housing and driving the poppet shaft up and down for up and down movement of the poppet,
Wherein the drive unit includes a cam driver for receiving the rotational force through the intermediate gears and moving the poppet shaft up and down,
The cam driving unit includes a cam-driven driven gear which is integrally formed with a cam portion and a gear shaft having a cam hole, is partially meshed with an intermediate gear of the intermediate gears and rotates about a horizontal rotation axis, And a sensing magnet coupled to the roller plate and rotatably coupled to the roller plate to move along the cam hole and to a point spaced from the drive line of the poppet shaft on one side of the roller plate, ,
Wherein the cam-driven driven gear includes a half-moon-shaped body portion having a toothed-shaped arc engaging with one of the intermediate gears, and the cam portion and the gear shaft are engaged with the front and back surfaces of the half- Respectively,
Wherein the poppet shaft includes a horizontal surface near a base end, the poppet shaft is fixedly coupled to the roller plate by welding between the horizontal surface and the roller plate after the horizontal surface overlaps the front surface or the back surface of the roller plate,
Wherein the housing includes a first gear mounting portion including an arcuate inner surface corresponding to a rotation locus of the cam-driven driven gear, and an arcuate inner surface corresponding to a rotation locus of the intermediate gear having the largest diameter among the intermediate gears A second gear mounting portion formed to intersect a predetermined region with the first gear mounting portion in an intersecting manner, a flange portion for connecting the flow path opened and closed by the poppet, Wherein the direction of movement of the poppet shaft is limited so that the poppet shaft can only be moved in the longitudinal direction within the connection portion, the connection portion being gradually narrowed to the flange portion,
Wherein the housing includes a cooling passage partially surrounding the poppet center on the side of the flange portion, the cooling passage including a first line portion coinciding with a tangent to an imaginary circle centering on the poppet center, And second and third line portions intersecting with the virtual circle adjacent to both sides of the poppet center at an angle of 90 degrees or more with the first line portion,
Wherein the poppet shaft includes a plurality of dimples continuously formed along the longitudinal direction.

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