KR101377271B1 - Waste gate valve manufacturing method for turbo charger - Google Patents

Abstract

The present invention relates to a method for manufacturing a waste gate valve for an automobile turbocharger, which can obtain a high-precision waste gate valve without post-processing or post-processing, thereby improving quality while reducing the overall production cost;
Before the valves, levers and washers constituting the waste gate valve are integrally formed through metal injection molding, the valves, levers and washers are inserted in the state of inserting the resin-molded gap retaining material. After injection molding, degreasing and sintering are performed to remove the gap retaining material so as to obtain a waste valve gate having a target gap between the valve, the lever, and the washer.

Description

Waste gate valve manufacturing method for automobile turbocharger {WASTE GATE VALVE MANUFACTURING METHOD FOR TURBO CHARGER}

The present invention relates to a method for manufacturing a waste gate valve for an automobile turbocharger, and more particularly, to make the waste gate valve used in an automobile turbocharger by metal powder injection molding, thereby reducing the process quality and durability. The present invention relates to the provision of an improved method.

In general, when more mixed air is supplied into the cylinder of the engine, the engine can generate more power at the same speed, generating high pressure and improving power during the expansion stroke.

As such, a turbocharger is used to supply excessively mixed air into the cylinder. However, if the boost pressure applied to the intake manifold is too high, abnormal combustion may occur and damage to the engine may be suppressed. To this end, a turbo gate is formed on the turbocharger, and a waste gate valve is provided to open and close the waste gate.

When the boost pressure reaches a constant value by the waste gate and the waste gate valve, a portion of the exhaust gas bypasses the turbine and flows to the waste gate so as to be discharged to the outside without rotating the turbine.

The configuration of the above-described turbocharged waist glove valve will be described with reference to FIG. 5.

In the cylinder 1 of the engine, the compressed air is ignited and expanded, and the exhaust valve 2 is opened. As the piston 3 is raised again, the combustion gas is discharged, and the exhaust gas discharged is turbocharged. The turbine 6 is rotated while passing through the exhaust gas inflow pipe 5 of (4).

As the pen 8 of the compressor 7 rotates while operating simultaneously with the turbine 6 rotated by the exhaust gas, external air is forcibly supplied into the cylinder 1 to increase the engine output.

However, if all the exhaust gas discharged rotates the turbine 6, excessive boost pressure may be generated in the intake manifold 9, which may cause abnormal combustion or engine abnormality.

In order to solve this problem, a waste gate 10 is formed in the inlet pipe 5, and the waste gate 10 is configured to be selectively opened and closed by the waste gate valve 11.

When excessive boost pressure is generated in the intake manifold 9, the waste gate valve 11 is opened so that a part of the exhaust gas discharged from the cylinder 1 bypasses the turbine 6 immediately without bypassing the bypass. This prevents excessive boost pressure.

The waste gate valve 11 as described above is provided in a disc shape, the valve 12 connected to and separated from the waste gate 10, and the valve shaft 13 integrally formed to protrude in the center of the valve 12. ), A lever 14 coupled to the valve shaft 13 to receive an operating force from an actuator, and a washer 15 coupled to an outer end of the valve shaft 13 to prevent the lever 14 from being separated. It is composed.

The valve shaft 13 and the lever 14 have a gap of about 0.2 mm so that the valve shaft 13 and the lever 14 can move independently of each other, so that the valve shaft 13 and the valve shaft 13 can be freely maintained. The washer 15 is configured not to be separated through welding.

The turbocharged waste valve gate, which serves as described above, controls the amount of air exhausted through repeated opening and closing operations, and repeatedly moves up and down at a high temperature of 1100 ° C. Valves, levers and washers are manufactured independently through precision casting with nickel base alloys to withstand them.

The lever is coupled to an independently manufactured valve as described above, and the valve shaft and the washer are integrated by welding to prevent the lever from being separated after the washer is coupled to the outer end of the valve shaft integrally formed with the valve.

Since the above-mentioned waste gate valve is completed independently through precision casting, and each completed part must be precisely processed in order to increase precision and airtightness, it must bear manufacturing cost and additional processing cost, and have to go through many processes. As a result, production is not easy and causes cost increases.

And, the valve and the lever can be easily combined, but since the coupling state of the washer is determined according to the operator's sense or experience during the welding process of fixing the valve and the washer, the interference between the lever and the washer occurs in the actually mounted state. Or, there are many problems, such as difficult to ensure excellent and uniform quality, such as the lever does not work due to the abnormal combination of the washers.

Accordingly, the present invention has been invented to solve the problems described above, before the valve, lever and washer constituting the waste gate valve are integrally formed through metal injection molding, injection molded with resin After injection molding the valve, lever and washer with metal powder in the state of inserting the gap retaining material, degreasing and sintering is performed to remove the gap retaining material to obtain a waste valve gate having a target gap between the valve, lever and washer. By obtaining;

The waste gate valve is made by injection molding, degreasing and sintering of metal powder in the state of inserting the gap retainer to obtain a high-precision waste gate valve without additional post-processing or post-processing, thereby reducing the overall production cost and improving quality. It is possible to achieve the purpose of providing a waste gate valve for an automotive turbocharger.

The present invention provides a product having excellent dimensional accuracy and improved surface roughness compared to the prior art while significantly reducing the production cost by allowing the production of the waste gate valve at a time through the metal powder injection molding. By making it possible to produce it is an invention having various effects, such as to eliminate the malfunction after mounting the actual vehicle.

1 is a block diagram of a waste gate valve for a vehicle turbocharger shown in order to explain the present invention.
2 is a process block diagram illustrating a manufacturing process of a waste gate valve for an automobile turbocharger to which the technique of the present invention is applied.
Figure 3 is a diagram illustrating a manufacturing process of the waste gate valve for the turbocharger to which the technique of the present invention is applied.
Figure 4 is a cross-sectional view showing a pre-production state and a complete manufacturing state of the waste gate valve for automobile turbocharger to which the technique of the present invention is applied.
Figure 5 is a block diagram showing a waste gate valve for a vehicle turbocharger to which the prior art is applied.

Hereinafter, with reference to the accompanying drawings look at a preferred manufacturing example of the present invention for achieving the above object.

1 is a block diagram of a waste gate valve for a vehicle turbocharger shown in order to explain the present invention, Figure 2 is a process block diagram showing a manufacturing process of the waste gate valve for a vehicle turbocharger applied to the technology of the present invention, Figure 3 is FIG. 4 is a cross-sectional view showing a manufacturing state and a complete manufacturing state of a waste gate valve for an automobile turbocharger to which the technique of the present invention is applied. It will be described together as.

The waste gate valve 100 for an automobile turbocharger to which the technique of the present invention is applied includes a valve 101 constituting the waste gate valve 100, and a washer 103 intermittent the lever 102 and the lever 102. It is formed integrally through metal injection molding (MIM), and the spacer 101 is inserted between the valve 101 and the lever 102 and the washer 103 by inserting the valve 101 and the lever. (102) injection molding the washer 103 with metal powder, and then degreasing and sintering to form the valve 101, the lever 102, the washer 103 integrally with the metal powder while maintaining the gap holding member 105 The sintering removal is performed to obtain a turbocharged waste valve gate 100 having a target distance between the valve 101, the lever 102, and the washer 103.

The present invention is a mixing step of mixing the metal powder for forming the valve 101, the lever 102, the washer 103 constituting the spacer maintaining step (S100) and the turbocharged waste gate valve 100 ( S200 and the gap holding material insert step S300 for inserting the gap holding material 105 by using the mixed metal powder and the waste gate valve 100 for the turbocharger in the state of inserting the gap holding material 105. The injection molding step (S400) for injection molding, the degreasing step (S500) for removing the binder contained in the injection-molded molded body, and vacuum-sintering the degreasing injection molding at high temperature to remove the gap retaining material 105 It is composed of a sintering step (S600) to make a shape while maintaining the gap of the bar 102 to the valve 102 and the washer 103 to the desired bar.

In the gap holding material forming step (S100), as a resin having low heat resistance so that it can be totally decomposed without remaining in the metal powder in the sintering step (S600), polyoxymethylene, polyacetal, polyethylene, ), Injection molding using any one of polypropylene, polycarbonate, and polyvinyl acetate.

That is, injection molding is carried out using a conventional mold to have a thickness equal to an interval between the valve 101 and the lever 102 and the washer 103 constituting the waste gate valve 100 for an automobile turbocharger. The formation of the gap holding member 105 is completed.

In the mixing step (S200), 85 to 95wt% of the metal powder and 5 to 15wt% of the binder are mixed, and the metal powder is Inconel 713C powder and the binder is polyoxymethylene (POM) having a density of 1.10 to 1.5 g / cm 3 30 It is comprised from-85 wt%, 1-20 wt% of low density thermoplastic resins of 0.90-1.00 g / cm <3>, and 14-50 wt% of a dispersion reinforcing agent of density 0.88-1.00 g / cm <3>.

In addition, the particle size of the metal powder is preferably 7 to 15㎛, when the particle size of the metal powder is low, the surface area of the powder is increased to increase the consumption of the binder in order to ensure smooth injection property, the more the amount of the binder degreasing time Due to the increase of the residual binder content increases the problem of difficult to control the carbon content occurs.

In addition, when the particle size is high, degreasing of the binder becomes smooth, but the filling rate in the product is low, causing problems such as slumping during the sintering process. May appear

In the insert step (S300), the gap retaining material 105 is pre-molded in the injection molding machine for molding the mixed gate powder for the turbocharger 100.

In the injection molding step (S400), after the gap retaining material 105 is molded into a pellet (Pellet) type in a pulverizer to facilitate injection molding the mixture mixed inside the injection molding machine previously inserted into a temperature of 80 ~ 150 ℃ It forms in the shape of the turbocharged wastegate valve 100 in the range.

In the degreasing step (S500), the solvent extraction process is a primary binder degreasing step for removing the low melting point binder and the surfactant. Hexane is used as the solvent, and the solvent temperature is raised to 35 to 60 ° C. Remove the binder.

At this time, if the waste gate valve 100 injection molded product degreasing time is about 5 to 8 hours based on the insertion time of the actual waste gate valve 100 injection molded product, the debinding ratio of the sub-binder will be 99% or more. The mold retaining ability is excellent even after the sub-binder is completely removed, and the size of the molded product does not change even after the solvent is completely dried.

After the degreasing is performed, the wet-drying method combined with the wet-drying method performed in the solvent extraction apparatus and the dry-drying method performed in the air during the drying process of the injection-molded waste gate valve 100 is performed by vaporizing hexane as a solvent. To prevent the crack of the waste gate valve 100 injection molding due to the sudden volatilization of.

In the thermal decomposition degreasing process as the secondary binder removal process, polyoxymethylene and low-density thermoplastic resins are decomposed and removed as heat, and carbon components, which are residual binder components generated in the manufacturing process, are removed to remove metal properties that may occur in the sintering process. Changes can be prevented.

In the sintering step (S600), in the sintering step (S5) using a high vacuum sintering furnace in a vacuum and nitrogen gas atmosphere sintered at a maximum temperature of 1280 ~ 1360 ℃ section, maintained at the maximum temperature for 100 to 200 minutes and then cooled The sintered product is completed.

In this process, when the injection molded body of the waste gate valve 100 is formed by using the metal powder, the gap holder 105 inserted is completely sintered and removed, and thus, the gap holder 105 has a space therein. The valve 101 and the washer 103 are integrally formed, and the lever 102 can move independently of the valve 101 and the washer 103.

The present invention as described above, by producing the waste gate valve through the injection molding and degreasing and sintering of the metal powder in the state of inserting the gap holding material to obtain a high-precision waste gate valve without additional post-processing or post-processing overall production cost It has the advantage of increasing the quality while reducing.

100; Waste gate valve
101; valve
102; lever
103; washer
105; Spacing

Claims (2)

Before integrally forming the valves, levers and washers constituting the waste gate valve through metal injection molding;
Performing injection molding of the valve, lever and washer with metal powder in the state of inserting the injection molding gap retaining material with resin, followed by degreasing and sintering;
A method of manufacturing a waste gate valve for an automobile turbocharger, comprising: removing a gap retaining material to obtain a waste valve gate having a target gap between the valve, the lever, and the washer. The method of claim 1, further comprising:
The spacer may be any one of polyoxymethylene, polyacetal, polyethylene, polypropylene, polycarbonate, and polyvinyl acetate. Method for manufacturing waste gate valve for automobile turbocharger.

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