KR101601764B1 - Manufacturing method for exhaust gas recirculaton control valve - Google Patents

Abstract

The present invention relates to a method for manufacturing an exhaust gas recirculation valve in which the inside of a valve body in which a valve assembly is assembled is made of a material having high wear resistance and the other valve body portion is made of a material easy to be molded.
The present invention also relates to a method of manufacturing an exhaust gas recirculation valve that improves manufacturing characteristics by performing insert molding and casting of insert water into a valve body mold and a post-processing step of physically processing the valve body, respectively.

Description

Technical Field [0001] The present invention relates to an exhaust gas recirculation control valve,

The present invention relates to a method for manufacturing an exhaust gas recirculation valve in which the inside of a valve body in which a valve assembly is assembled is made of a material having high wear resistance and the other valve body portion is made of a material easy to be molded.

The present invention also relates to a method of manufacturing an exhaust gas recirculation valve that improves manufacturing characteristics by performing insert molding and casting of insert water into a valve body mold and a post-processing step of physically processing the valve body, respectively.

Generally, automobiles, especially diesel engines such as internal combustion engines, use an exhaust gas recirculation valve (EGR valve), which functions to add exhaust gas discharged from the internal combustion engine to intake air supplied to the internal combustion engine do.

Therefore, the decrease of the oxygen content in the intake air and the decrease in the temperature of the combustion chamber due to the increase of the carbon dioxide concentration in the intake air reduce the emission of contaminants such as nitrogen oxides (NOx).

On the other hand, various types of exhaust gas recirculation valves are proposed in various documents including Korean Patent No. 10-0378453, Korean Patent No. 10-0995915 and Korean Patent No. 10-0586782.

For example, in Korean Patent No. 10-0586782, as shown in FIG. 1, an exhaust gas inlet is provided at the lower end of a valve body, and an exhaust gas outlet is provided at a side of the valve body. The exhaust gas inlet is connected to the exhaust portion of the internal combustion engine, To the intake air supply pipe.

The valve seat 12 is provided in the exhaust gas inlet and the valve shaft 14 is operated by the motor 20 to open and close the valve seat 12 to open the valve seat 12 to exhaust the exhaust gas to the intake air supply pipe Recirculate.

However, in the conventional exhaust gas recirculation valve, a valve body is usually manufactured by a metal casting method in which a molten metal is injected into a mold, and aluminum (Al), which is easy to mold, is used as a molten metal.

The valve assembly including the motor 20, the valve shaft 14 and the valve head 11 is fitted to the valve body cast as described above and the valve shaft 14 is connected to the valve guides 16 and 17 ).

Therefore, the valve guides 16 and 17, which support the valve shaft 14 during the reciprocating motion of the valve shaft 14, are abraded by the motor 20, resulting in poor durability and malfunctions.

Further, since the valve head 11 provided at the end of the valve shaft 14 also repeatedly contacts the valve seat 12, abrasion occurs, thereby causing leakage between the valve head 11 and the valve seat 12 .

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems and it is an object of the present invention to provide an exhaust gas recirculation valve manufacturing method in which the inside of a valve body in which a valve assembly is assembled is made of a material with high wear resistance, .

The present invention also provides a method of manufacturing an exhaust gas recirculation valve that improves manufacturing characteristics by performing insert molding of insert water into a valve body mold and post-processing steps of physically processing the valve body, respectively.

To this end, the method for manufacturing an exhaust gas recirculation valve according to the present invention comprises the steps of: preparing an insert water material having a wear resistance higher than that of a valve body, filling the portion where the valve assembly is assembled during casting; Inserting the formed insert water into a mold having a shape corresponding to the valve body; A valve body molding step of injecting molten metal into the mold in which the insert water is inserted to cast the valve body; A valve post-treatment step of machining insert water inside the molded valve body to form an assembly hole in which the valve assembly is assembled; And a valve assembling step of assembling the valve assembly to the insert hole of the insert.

At this time, it is preferable to prepare an insert material having a high resistance to abrasion in the insert water preparing step, and inject molten metal of aluminum material which is easy to be cast in the valve body forming step.

In addition, it is preferable to further include an insert water preheating step for preheating the prepared insert water between the insert water preparing step and the insert water inserting step.

The valve assembly includes a valve shaft reciprocating by a driving device, and a valve head coupled to an end of the valve shaft to open and close the flow passage. In the insert water preparation step, the valve supporting the reciprocating motion of the valve shaft It is preferable that a guide insert is prepared, and in the valve post-processing step, a hollow portion in which the valve shaft is fitted is formed through the valve guide insert.

In addition, the step of preparing the insert material may include: a first insert water preparation step of independently forming each part of the insert material having a plurality of configurations; And a second insert water preparation step of assembling the molded parts to each other.

In addition, each part of the first insert material preparing step may include the valve guide insert, a valve seat insert disposed downwardly from the valve guide insert, and a connection for connecting the valve guide insert and the valve seat insert Wherein the valve guide insert, the connecting insert, and the valve seat insert are sequentially subjected to a drilling process in the valve post-processing step to insert a hollow portion into which the valve shaft is inserted through the valve guide insert , It is preferable to remove the connecting insert.

In the valve post-processing step, it is preferable to form the valve seat for the valve seat by molding the valve seat insert.

Further, in the valve post-treatment step, at least one of a suction line for supplying the intake air for combustion to the valve body and a recirculation line for mixing the exhaust gas of the internal combustion engine into the intake air may be further included desirable.

As described above, in the present invention, the inside of the valve body in which the valve assembly is assembled is made of a material having high abrasion resistance such as stainless, and the outer portion thereof is made of a material such as aluminum that is easily castable.

Therefore, the present invention prevents wear of a portion contacting with the valve assembly even if the valve assembly is repeatedly operated by the driving device, thereby improving durability and operational reliability.

Further, the present invention carries out a post-treatment step of machining an assembler and an exhaust gas recirculation passage in which the valve assembly is assembled to the valve body after the step of inserting insert water into the mold and casting the valve body.

Therefore, the present invention makes it possible to manufacture an exhaust gas recirculation valve easily while still ensuring precise valve manufacturing.

1 is a front sectional view showing an exhaust gas recirculation valve according to the prior art.
2 is a perspective view of a first embodiment of an exhaust gas recirculation valve manufactured by a method of manufacturing an exhaust gas recirculation valve according to the present invention.
3 is a perspective view showing a second embodiment of an exhaust gas recirculation valve manufactured by the exhaust gas recirculation valve manufacturing method according to the present invention.
4 is a flowchart showing a method of manufacturing an exhaust gas recirculation valve according to the present invention.
FIG. 5 is an exploded view showing insert water used in the method of manufacturing an exhaust gas recirculation valve according to the present invention. FIG.
FIG. 6 is a joint state diagram showing insert water used in the method of manufacturing an exhaust gas recirculation valve according to the present invention. FIG.
7 is a view showing a casting method in a state where an insert water is inserted in an exhaust gas recirculation valve manufacturing method according to the present invention.
8A is a view showing a first post-treatment step of the exhaust gas recirculation valve manufacturing method according to the present invention.
8B is a view showing a second post-treatment step of the exhaust gas recirculation valve manufacturing method according to the present invention.
9 is a view illustrating a valve assembly assembling step of the exhaust gas recirculation valve manufacturing method according to the present invention.

Hereinafter, a method of manufacturing an exhaust gas recirculation valve according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, the structure of the exhaust gas recirculation valve (EGR valve) manufactured by the present invention will be described in order to facilitate understanding of the exhaust gas recirculation valve manufacturing method according to the present invention.

However, it is apparent that the exhaust gas recirculation valve described below is only one embodiment of various types of exhaust gas recirculation valves to which the present invention can be applied, and that the present invention can be applied to other exhaust gas recirculation valves.

As shown in FIGS. 2 and 3, the exhaust gas recirculation valve manufactured by the present invention includes a valve body 100 and an insert object provided therein. The insert water is used as an assembly in which the valve assembly is assembled by subsequent treatment.

The valve assembly includes a valve shaft 310 and a valve head 320 reciprocating up and down by a driving device as shown in Fig. The insert water 200 thus includes a valve guide insert 210 that supports the valve shaft 310 and a valve seat insert 220 that is opened and closed by the valve head 320.

A suction line inlet IN is formed on one side of the valve body 100 through post-processing and a suction air outlet OUT is formed on the other side of the valve body 100 to form a suction line (IN, OUT).

In such a valve configuration, a suction air supply pipe is normally connected to the suction air inlet IN and a suction air outlet OUT, respectively, and in particular, a pipe connected to the suction air outlet OUT side is connected to the internal combustion engine.

A recirculation line Re through which the exhaust gas of the internal combustion engine is mixed with the intake air is formed in the lower portion of the valve body 100. The recirculation line Re is connected to the suction lines IN and OUT ≪ / RTI >

Accordingly, when the valve is opened by the valve assembly, the exhaust gas discharged from the internal combustion engine is introduced (that is, recirculated) into the intake air intake lines IN and OUT through the recirculation line Re, Mixed and then supplied to the internal combustion engine.

4, the method for manufacturing an exhaust gas recirculation valve according to the present invention includes an insert water preparing step S110, an insert water inserting step S120, a valve body forming step S130, Processing step S140 and valve assembly step S150.

Further, preferably, the insert water preheating step (S120a) is further included between the insert water preparing step (S110) and the insert water inserting step (S120) as described above. That is, the prepared insert material 200 is preheated before casting.

The insert material preparation step S110 is a step of filling the valve body 100 with an inner center portion of the valve body 100 in which the valve body 100 is assembled when casting the valve body 100, (200) is molded and prepared.

For example, in the insert preparation step (S110), an insert material (200) made of stainless steel (SUS) having a high wear resistance is prepared. On the other hand, in the valve body forming step (S130) to be described later, molten metal of aluminum (Al) material which is easy to cast is injected.

Accordingly, the inner center portion of the exhaust gas recirculation valve is made of a stainless steel material having high abrasion resistance, and the valve body 100 on the outside of the exhaust gas recirculation valve is made of a double material structure made of aluminum material.

Thus, even when the valve assembly (e.g., the valve shaft 310 and the valve head 320) is operated for a long time, the casting of the valve body 100 is facilitated while improving wear resistance.

Particularly, the insert preparation step (S110) of the present invention comprises a first insert preparation step (S110a) of independently forming each part of the insert product (200) having a plurality of configurations, and a step And a second insert water preparation step (S110b).

5, the insert 200 includes a valve guide insert 210, a valve seat insert 220, and a connection insert 230. In the first insert water preparation step S110a, Molded and prepared independently.

Here, the valve guide insert 210 becomes a valve guide through a subsequent post-treatment process, and the valve seat insert 220 is subjected to a post-treatment process to become a valve seat. The connection insert 230 is completely removed through a post-treatment process.

That is, by drilling the valve guide insert 210, the connection insert 230, and the valve seat insert 220 sequentially arranged in the valve post-processing step S140, the valve guide insert 210 is inserted into the valve shaft insert 210, (Not shown), and the connecting insert 230 is removed.

Next, as shown in FIG. 6, the valve insert 210 and the valve seat insert 220 are connected to the upper and lower portions using the connection insert 230 in the second insert preparation step S110b.

For example, a connecting bolt protrudes from the top and bottom of the connection insert 230, and a screw hole is formed in the valve guide insert 210 and the valve seat insert 220, respectively, I finish preparation of.

Therefore, insert water 200 is inserted to maintain its shape during casting. The length of the connection insert 230 is determined by the interval between the valve guide and the valve seat determined for each valve.

Next, in the insert water preheating step S120a, the insert water 200 prepared as described above is preheated. Preheating is performed by putting the insert water 200 into the preheating chamber and heating at about 200 DEG C for 30 minutes.

The reason why the insert 200 is preheated is because the surface temperature of the insert 200 prepared in advance is too low and the temperature of the insert 200 inserted between the mold 200 and the molten metal in the subsequent valve body 100 casting process In order to prevent the temperature difference from increasing.

In other words, if the hot water is injected into the mold and the hot molten metal for molding the valve body 100 is injected, the bonding force of the interface is weakened and cracks are generated, so that the insert water 200 ) After preheating.

Next, in the insert water inserting step (S120), the preheated insert water 200 is inserted into a mold having a shape corresponding to the valve body 100.

In the valve body forming step S130, molten metal is injected into the mold in which the insert 200 is inserted, thereby casting the valve body 100.

7 schematically shows a mold M and a molten metal injector I wherein the insert 200 is disposed at the center of the mold so that the valve body 100 is integrally formed on the outside of the insert 200 .

As described above, since the insert material 200 is made of stainless steel having high abrasion resistance, the molten metal injected into the mold M is aluminum, so that the casting operation can be facilitated and the valve body 100 of a precise shape can be manufactured .

Next, in the valve post-treatment step (S140), the valve body 100 cast as described above and the insert water 200 therein are processed to assemble the valve assembly to the insert water 200.

The valve post-treatment step S140 includes a step of forming the valve assembly assembly by machining the insert material 200 and forming the valve assembly assembly through the lines IN, OUT, and OUT in which the intake air and the exhaust gas flow for combustion flows into the valve body 100, Re).

8A, drilling is performed for the valve guide insert 210, the connection insert 230, and the valve seat insert 220, which are sequentially disposed by using the drill (D) when the insert 200 is machined.

Therefore, the hollow portion in which the valve shaft 310 is fitted is formed through the valve guide insert 210, and the connection insert 230 is removed. In addition, the valve seat insert 220 can also be preliminarily machined by the drilling operation described above.

Drilling is performed in various directions depending on the type of valve, from top to bottom, from bottom to top, or from top to bottom, respectively. In FIG. 8A, it is assumed that the process proceeds from the lower side to the upper side.

The diameter of the drill D is made to correspond to the diameter of the valve shaft 310 fitted in the valve guide. However, since the connecting insert 230 is removed in the post-treatment process, it is made to be removed by the drill D using a material smaller than the diameter of the drill D.

8B, in the valve post-processing step S140, the valve seat insert 220 is formed to manufacture a valve seat into which the valve head 320 is fitted. The valve seat has, for example, an opening / closing hole in which the valve head 320 is fitted at the center thereof.

However, like the conventional valve, an inclined taper 221 is formed around the opening / closing hole of the valve seat so that the face 321 of the valve head 320 is seated on the tapered portion.

Furthermore, the suction line (IN, OUT) for supplying the intake air for combustion to the valve body 100 and the exhaust gas of the internal combustion engine are mixed with the intake air when the valve body 100 is machined during the valve post-treatment step S140 To form a recirculation line (Re).

For example, the front and rear of the valve body 100 are drilled to form the suction air inlet IN and the suction air outlet OUT, respectively, to form the suction lines IN and OUT, And a hole to be connected to the opening and closing hole of the valve seat is formed in the lower portion to form a recirculation line (Re).

Next, as shown in FIG. 9, in the valve assembling step S150, the valve assembly is assembled to the assembly hole of the insert 200.

The valve assembly includes a valve shaft 310 and a valve head 320 coupled to the end thereof. The valve shaft 310 is fitted into the valve guide formed by post-processing the valve guide insert 210 and the valve head 320 is fitted into the formed valve seat by post-processing the valve head insert 220.

The valve head 320 is integrally provided at the lower end of the valve shaft 310 and has a larger diameter of the valve head 320, thereby assembling the valve assembly from below. After inserting the valve assembly, assemble the drive unit on top of the valve guide.

Accordingly, when the driving device is operated to lower the valve shaft 310, the valve head 320 and the valve seat are disengaged and opened. When the valve is opened in this manner, the exhaust gas flows into the intake air and is supplied together with the intake air.

The specific embodiments of the present invention have been described above. It is to be understood, however, that the scope and spirit of the present invention is not limited to these specific embodiments, and that various modifications and changes may be made without departing from the spirit of the present invention. If you have, you will understand.

Therefore, it should be understood that the above-described embodiments are provided so that those skilled in the art can fully understand the scope of the present invention. Therefore, it should be understood that the embodiments are to be considered in all respects as illustrative and not restrictive, The invention is only defined by the scope of the claims.

100: valve body
200: insert object
210: Insert for valve guide
220: Insert for valve seat
230: connection insert
310: valve shaft
320: valve head

Claims (8)

A method for manufacturing an exhaust gas recirculation valve for mixing exhaust gas from an internal combustion engine with intake air in accordance with opening and closing operations of a valve assembly operated in a valve body (100)
(S110) for forming an insert object (200) having a wear resistance higher than that of the valve body (100) by filling a portion where the valve assembly is assembled at the time of casting;
(S120) of inserting the molded insert into a mold having a shape corresponding to the valve body (100);
A valve body molding step (S130) of injecting molten metal into the mold in which the insert material (200) is inserted to cast the valve body (100);
A valve post-treatment step (S140) of processing an insert material (200) inside the molded valve body (100) to form an assembly hole in which the valve assembly is assembled to the insert material (200); And
(S150) assembling the valve assembly to an assembler of the insert material (200);
The valve assembly includes a valve shaft (310) reciprocating by a driving device, and a valve head (320) coupled to an end of the valve shaft (310) to open and close a flow path,
In the insert preparation step S110, a valve guide insert 210 for supporting the reciprocating movement of the valve shaft 310 is prepared,
Wherein in the valve post-treatment step (S140), a hollow portion through which the valve shaft (310) is fitted is formed through the valve guide insert (210). The method according to claim 1,
In the insert water preparation step (S110), an insert material (200) of stainless steel having a high abrasion resistance is prepared,
Wherein the step of forming the valve body (S130) comprises injecting molten metal of an aluminum material which is easy to cast. The method according to claim 1,
(S120a) for preheating the prepared insert material (200) between the insert preparation step (S110) and the insert water inserting step (S120). delete The method according to claim 1,
The insert preparation step (S110)
A first insert water preparation step (S110a) for independently forming each part of the insert material (200) having a plurality of configurations; And
And a second insert water preparation step (S110b) of assembling the molded parts to each other. 6. The method of claim 5,
Each part of the first insert preparation step S110a includes the valve guide insert 210, the valve seat insert 220 spaced downward from the valve guide insert 210, (230) connecting the valve seat insert (210) and the valve seat insert (220) to each other,
In the valve post-treatment step S140, the valve guide insert 210, the connection insert 230, and the valve seat insert 220 are sequentially drilled to sequentially position the valve guide insert 210, Wherein a hollow portion into which the valve shaft (310) is fitted is formed through a through-hole, and the connecting insert (230) is removed. The method according to claim 6,
Wherein in the valve post-treatment step (S140), the valve seat insert 220 is molded to manufacture a valve seat into which the valve head 320 is fitted. The method according to claim 1,
In the valve post-treatment step S140, a suction line (IN, OUT) for supplying intake air for combustion to the valve body 100 and a recirculation line (Re) for mixing the exhaust gas of the internal combustion engine with the intake air Further comprising molding at least one of the plurality of exhaust gas recirculation valves.

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