JP2003049606A - Method of manufacturing component of exhaust guide assembly in vgs-type turbo charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method of manufacturing components, capable of improving the productivity by minimizing the cutting work in a manufacturing process of the components of an exhaust guide assembly in a VGS-type turbo charger, by technically improving a mold member such as a punch an dies. SOLUTION: In this method of forming the components of the objective shape by performing one or a plurality of processes such as punching, drawing, coining, embossing, bending, casting, header, caulking, ironing and form rolling onto a work W by comparatively simple pressing work mainly by means of the punch 61 and the dies 62, the material, hardness and toughness of the punch 61 and the dies 62 are selected on the basis of the optimizing analysis. The punch 61 is provided with a taper face TS for dispersing the stress acting on a cutting part C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbocharger used in an automobile engine or the like,
In particular, when the constituent members of the exhaust guide assembly to be incorporated into this product are manufactured by appropriate processing such as punching, drawing, etc., mainly by applying punches and dies, punching is performed according to the shape to be molded and the processing content. The present invention relates to a novel manufacturing method in which the material, hardness, and toughness of a mold such as a die or die are selected.

[0002]

BACKGROUND OF THE INVENTION A turbocharger is known as a supercharger used as a means for increasing the output and improving the performance of an automobile engine. This turbocharger drives a turbine by the exhaust energy of the engine, It is a device that rotates the compressor by the output and brings the engine into a supercharged state that is higher than natural intake. By the way, in this turbocharger, when the engine is rotating at a low speed, the exhaust turbine hardly works due to a decrease in the exhaust flow rate, and therefore, in the case of an engine that can rotate up to a high rotation range, the turbine has a feeling of rattling until it rotates efficiently, It was inevitable that the so-called turbo lag, etc., required for the subsequent blowing up of the air all at once. Also, the diesel engine, which has a low engine speed, has a drawback that it is difficult to obtain a turbo effect.

For this reason, a VGS type turbocharger has been developed which operates efficiently even in a low rotation range. Even in low-speed rotation, this type uses multiple variable blades (wings) arranged on the outer circumference of the exhaust turbine to narrow down the exhaust gas with a small flow rate, increase the speed of exhaust, and increase the work of the exhaust turbine. It is designed to exhibit high output. For this reason, the VGS type turbocharger requires a separate variable blade variable mechanism,
The peripheral components also had to be more complicated in shape and the like than conventional ones.

In manufacturing such a VGS type turbocharger, the constituent members of the exhaust guide assembly for controlling the flow rate of the exhaust gas, such as the variable blades and the turbine frame for rotatably holding the variable blades, are manufactured. , For example, by a precision casting method typified by lost wax casting, after first forming a metal material (form) that is the original form of each component, cutting the form to obtain the desired shape or The method of finishing to dimensions is common.

However, such a cutting method has the following disadvantages. That is, since this type of turbo equipment is generally used in a high temperature and exhaust gas atmosphere, heat resistant stainless steel such as SUS310S having excellent heat resistance and oxidation resistance is also applied to various components. However, such a material is generally difficult to cut, and there is a problem that it takes a long time for cutting and it takes time to process. By the way, when it comes to variable vanes, one per turbocharger
Since about 0 to 15 are required, the actual monthly production of automobiles is 3
If about 10,000 units are mass-produced, it is necessary to manufacture 300,000 to 450,000 units per month, and it was not possible to deal with the cutting process at all (the number of receiving holes for rotatably holding the variable blade). Also for).

Therefore, in order to eliminate the time-consuming cutting process as much as possible, a method of manufacturing the constituent members by a relatively simple pressing process (punching, drawing, etc.) by a die, which mainly applies punches and dies, is proposed. Has been issued. However, since the constituent members of the exhaust guide assembly are heat-resistant members and the like, it is difficult to perform the simple pressing process using the above-described mold, and it is not a processing method that can be easily realized. For this reason, the applicant has made the shapes of the constituent members so that simple press working with such a mold can be performed.
We are improving and technologically developing the processing method itself and processing conditions.

[0007]

The present invention has been made as a part of such development, and the constituent members of the exhaust guide assembly are mainly formed by technically devising die members such as punches and dies. The cutting process is eliminated as much as possible from the manufacturing process of (1) to improve the mass productivity of the constituent members. In recent years, especially in diesel vehicles,
Exhaust gas emitted into the atmosphere is currently strongly regulated from the viewpoint of environmental protection, and NO _x and particulate matter (P
In order to reduce M) and the like, mass production of a VGS type turbocharger that can improve the efficiency of the engine from a low rotation range is desired.

[0008]

That is, a method of manufacturing a constituent member of an exhaust guide assembly in a VGS type turbocharger according to a first aspect of the present invention is to hold a plurality of variable blades rotatably at an outer peripheral position of an exhaust turbine, The relatively small amount of exhaust gas discharged from the engine is appropriately narrowed down by this variable vane, the speed of the exhaust gas is amplified, the exhaust turbine is rotated by the energy of the exhaust gas, and the compressor directly connected to this exhaust turbine produces air above the natural intake air. To produce the components of the exhaust guide assembly that is incorporated into the VGS type turbocharger that enables the engine to deliver high output even at low speeds. Punching, squeezing, coining and bossing by punching and dies , Bending, forging, header, caulking,
Ironing, one of a plurality of rolling processes, in the method of forming a constituent member of the desired shape, depending on the desired shape of the work, and the processing method to be applied to the work,
It is characterized in that selection of materials, hardness and toughness of punches and dies are optimized and analyzed and applied. According to this invention, the material of the punch and the die, the hardness, and the toughness are analyzed according to the processing method applied to the metal material (workpiece) and the target shape, and the optimum state is selected. The member can be finished as a single piece with a high accuracy of, for example, a tolerance of ± 0.01 mm. Further, the life of die members such as punches and dies can be extended.

According to a second aspect of the present invention, there is provided a method for manufacturing a constituent member of an exhaust guide assembly for a VGS type turbocharger, wherein in addition to the requirements of the first aspect, the punch has a taper surface on a cutting edge portion. The stress applied to the cutting edge portion at the time of shearing is dispersed. According to the present invention, the cutting edge portion of the punch is formed with the tapered surface for stress distribution, so that the durable life of the die member such as the punch or the die can be further improved.

According to a third aspect of the present invention, there is provided a method of manufacturing a constituent member of an exhaust guide assembly for a VGS type turbocharger, wherein, in addition to the requirements of the first or second aspect, when the work is formed into a member having a desired shape, When including a blank material punching step and a step of opening a hole in the punched blank material, the punching process and the punching process are performed by a single pressing stroke of the punch. Is. According to this invention,
The blank material shape punching process and the punching of the punched blank material can be performed all at once by one pressing operation of the punch, which contributes to the improvement of the productivity of the constituent members of the exhaust guide assembly.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments. The present invention is applied when manufacturing the exhaust guide assembly A in the VGS type turbocharger, specifically, when joining various constituent members of the exhaust guide assembly A. The exhaust guide assembly A will be described. The exhaust guide assembly A adjusts the exhaust gas flow rate by appropriately narrowing the exhaust gas G when the engine is rotating at a low speed, and is provided on the outer periphery of the exhaust turbine T as shown in FIG. A plurality of variable blades 1 for setting the flow rate, a turbine frame 2 for rotatably holding the variable blade 1, and a variable mechanism 3 for rotating the variable blade 1 by a certain angle to appropriately set the flow rate of the exhaust gas G are provided. It consists of. Hereinafter, each component of the exhaust guide assembly A will be described.

First, the variable blade 1 will be described. As an example, as shown in FIG. 1, a plurality of these are arranged in an arc shape along the outer periphery of the exhaust turbine T (one exhaust guide assembly A
Approximately ten to fifteen of them are disposed, and each of them is rotated by approximately the same degree to appropriately adjust the exhaust gas flow rate. Each variable blade 1 comprises a blade portion 11 and a shaft portion 12. The blade portion 11 is formed so as to have a constant width mainly according to the width dimension of the exhaust turbine T, the cross-section in the width direction thereof is formed into a substantially blade shape, and the exhaust gas G is effectively exhaust turbine. It is configured to go to T. Here, the width dimension of the blade portion 11 is referred to as a blade height h for convenience. In addition, the shaft portion 12 is formed so as to be continuous with the wing portion 11 integrally, and is a portion corresponding to a rotating shaft when the wing portion 11 is moved.

At the connecting portion between the blade portion 11 and the shaft portion 12, there is provided a taper portion 13 that narrows from the shaft portion 12 toward the blade portion 11, and a flange portion 14 having a diameter slightly larger than that of the shaft portion 12. Are formed to be continuous. The bottom surface of the collar portion 14 is formed substantially on the same plane as the end surface of the blade portion 11 on the shaft portion 12 side, and this plane serves as a sliding surface when the variable blade 1 is attached to the turbine frame 2, The smooth rotating state of the blade 1 is ensured. Furthermore, at the tip of the shaft 12,
A reference surface 15 is formed which serves as a reference for the mounting state of the variable blade 1. The reference surface 15 is a portion that is fixed to the variable mechanism 3 described later by crimping or the like. As an example, as shown in FIG. And is formed in a substantially constant inclination state.

Next, the turbine frame 2 will be described. This is configured as a frame member that rotatably holds a plurality of variable blades 1. As an example, as shown in FIG. 1, the variable blade 1 is sandwiched by a frame segment 21 and a holding member 22. Is configured as follows. The frame segment 21 is provided with a flange portion 23 that receives the shaft portion 12 of the variable blade 1 and a boss portion 24 that fits the variable mechanism 3 described later on the outer circumference. Due to such a structure, the flange portion 23 is formed with the same number of receiving holes 25 as the variable blades 1 at the peripheral portion, and in the present invention, the receiving holes 25 are formed with high efficiency. , It is also finished with high precision. Therefore, the substantial application target of the present invention is the frame segment 21.

Further, the holding member 22 is formed in a disc shape having a central portion opened as shown in FIG. The dimension of the variable blade 1 sandwiched between the frame segment 21 and the holding member 22 is substantially constant (generally, the blade width of the variable blade 1 is approximately constant so that the blade portion 11 of the variable blade 1 can always be smoothly rotated. The dimension between the two members is maintained by the caulking pins 26 provided at four locations on the outer peripheral portion of the receiving hole 25, for example. Here, the holes opened in the frame segment 21 and the holding member 22 for receiving the crimping pins 26 are referred to as pin holes 27.

In this embodiment, the flange portion 23 of the frame segment 21 has two flange portions, that is, a flange portion 23A having substantially the same diameter as the holding member 22 and a flange portion 23B having a diameter slightly larger than the holding member 22. , Which are made of the same material,
In the case where processing with the same member becomes complicated, it is also possible to form two flange portions having different diameters by dividing them and then to join them by caulking or brazing.

Next, the variable mechanism 3 will be described. This is provided on the outer peripheral side of the boss portion 24 of the turbine frame 2 and rotates the variable blade 1 in order to adjust the exhaust flow rate. As an example, as shown in FIG. The variable blade 1 includes a rotating member 31 that causes the variable blade 1 to rotate, and a transmission member 32 that transmits the rotation to the variable blade 1. The rotating member 31 is formed in a substantially disc shape with an opening in the central portion as shown in the figure, and the same number of transmitting members 32 as the variable blades 1 are provided at equal intervals on the peripheral portion thereof. The transmission member 32 includes a drive element 32A rotatably attached to the rotating member 31 and the variable blade 1.
Element 32 fixedly mounted on the reference plane 15 of the
B is included, and the rotation is transmitted in a state where the drive element 32A and the passive element 32B are connected. Specifically, a rectangular piece-shaped drive element 32A is rotatably pinned to the rotating member 31, and a passive element 32B formed in a substantially U shape so as to receive the drive element 32A is variable. Fixed to the reference surface 15 at the tip of the wing 1, and the square-piece-shaped drive element 32A is replaced by the U-shaped passive element 32.
The rotation member 31 is fitted in the B and is engaged with both.
Is attached to the boss portion 24.

In the initial state in which a plurality of variable vanes 1 are attached, in order to align them in a circumferential shape, each variable vane 1 and the passive element 32B need to be attached at a substantially constant angle. In the above embodiment, the reference surface 15 of the variable vane 1 mainly plays this role. Further, when the rotating member 31 is simply fitted in the boss portion 24, when the rotating member 31 is slightly separated from the turbine frame 2,
Since there is concern that the engagement of the transmission member 32 may be released, in order to prevent this, a ring 33 or the like is provided so as to sandwich the rotating member 31 from the opposite side of the turbine frame 2,
The rotation member 31 is given a tendency to be pressed toward the turbine frame 2 side. With such a configuration, when the engine rotates at a low speed, the rotating member 31 of the variable mechanism 3 is appropriately rotated, and the shaft portion 12 is moved through the transmission member 32.
And the variable blade 1 is rotated as shown in FIG. 1, the exhaust gas G is appropriately narrowed, and the exhaust flow rate is adjusted.

An example of the exhaust guide assembly A to which the present invention is applied is configured as described above, and a method of manufacturing the constituent members of the exhaust guide assembly of the present invention will be described below. According to the present invention, a relatively simple pressing process is performed on a metal material (workpiece W) which is excellent in heat resistance and is difficult to process, by a simple die member mainly including a punch or a die to obtain a desired shape. In obtaining a component having a shape and dimensional accuracy, the material, hardness, and toughness of the punch and the die are appropriately selected according to the shape of the component to be formed and the processing method to be applied.

The above-mentioned "relatively simple pressing work" means punching, drawing, coining, bossing, bending, forging, header processing, caulking (press caulking, spin caulking), which is mainly performed by a punch and a die. ), Ironing, and rolling, indicating one or more processes. In addition, the "punching" in this includes punching the blank material shape and punching holes in the blank material, and the punching method is a fine blanking method in addition to the punching method using a general press. It includes a (precision punching) method and the like. Furthermore, in the "drawing", in addition to the process of forming a blank material with a substantially constant thickness in the shape of a cup, a blank hole (preparing hole for burring) is opened in the blank material and then the blank is expanded by expanding this pilot hole. It also includes a burring process for forming the material into a substantially tubular shape or a substantially pipe shape.

Here, some examples of selecting the material of the mold member will be described. First, in forming the variable vane 1 which is one of the main constituent members of the exhaust guide assembly A, a heat resistant metal material having a tensile strength of 700 N / mm ² is applied,
When coining this to obtain the variable blade 1 as a finished member, the punch is made of a cemented carbide material (high toughness) and at the same time low temperature physical properties are used to further improve hardness and toughness. The die is vapor-deposited, and the die is made of the material of HAP72 having a hardness slightly lower than that of the punch (large toughness), and the die is not subjected to the low-temperature physical vapor-deposition treatment.

Also, a kind of frame segment 21
For example, when forming by a warm drawing method, copper-containing tool steel is applied to the fitting portion (punch receiving portion) of the die surface, and TD treatment is performed on the punch (diffusion film of titanium carbide etc. is formed by salt bath treatment). By improving the hardness and extending the life, the heat conductivity and the slip property of the flange portion 23 are made good, and a desired product can be processed. Furthermore, when the frame segment 21 different from this is formed by, for example, forging and ironing, in order to withstand a concentrated load,
As a die and punch die material, a Mo-based cemented carbide (having both high hardness and toughness) can be applied.

As described above, according to the present invention, the material, hardness, and toughness of the die member such as a punch or a die are appropriately selected according to the desired shape of the component member and the processing method. Therefore, the dimensional tolerance is ± 0. A highly accurate component member having a size of about 01 mm is obtained, and in the case of performing such processing, the durability limit of about 500 to 1000 shots is a normal mold member, but in the present invention, as an example, 5000 to 20000 The durability limit of the mold can be improved up to about a shot (about 5 to 40 times).

Further, in the present embodiment, as shown in FIG. 2 as an example, the cutting edge portion C of the punch 61 has a tapered surface T.
It forms S. The cutting edge portion C is the outermost peripheral portion of the punch 61. Generally, when shearing a metal plate material (workpiece W), the cutting edge portion C first bites into the workpiece W and cracks the workpiece W before the substantial shearing. Or, it is an action site for causing a crack. Therefore, since a large stress (load) is applied to such a cutting edge portion C during shearing, in the present embodiment, the cutting edge portion C is formed by the tapered surface TS.
The stress exerted on the die 61 is appropriately dispersed in the axial direction of the punch 61 and in the direction orthogonal to the axial direction to further prolong the life of the die member.

The taper surface TS shown in the drawing is the punch 61.
Is formed so as to have an angle of about 5 to 15 ° from the bottom surface of the punch 61 while being attached within a range of about 1 to 5 mm from the outermost edge of the punch 61. The stress acting on the blade portion C or the stress applied to the cutting edge portion C can be variously changed depending on how to disperse the stress. Of course, when such a form is adopted, as shown in FIG.
Forming the corner R (filleting) is a preferable form for further extending the mold life.

Further, among the constituent members of the exhaust guide assembly A, for example, a step of punching a blank material BL from a work W having a substantially constant plate thickness like the holding member 22, and a hole (holding member 22 in the blank material BL In this case, there is a member that is manufactured including the step of opening the pin hole 27). In such a case, the punch 61 includes a punching step of the blank material BL and an opening step to the blank material BL. It is possible to carry out in one stroke operation.

In the punching die 6 in such a case, as shown in FIG. 3 as an example, the punch 61 and the die 62 mainly involved in punching the blank material BL, and the punched blank material BL are reversed from the punch 61. It comprises a back pressure punch 63 which is pressed from the side, and a piercing punch 64 which mainly opens a hole in the blank material BL. The punch 61 is provided with a piercing punch 64 and a piercing receiving hole 61a for receiving the metal material (dust) punched by the piercing punch 64. Further, the back pressure punch 63 is configured to follow the pressing operation of the punch 61 while receiving the blank material BL, but the piercing punch 64 configured inside the back pressure punch 63 moves the back pressure punch 63. Regardless, it is configured in a fixed state. The distance from the surface of the die 62 holding the work W to the working tip of the piercing punch 64, that is, the gap between the back pressure punch 63 and the piercing punch 64 is
It is set to be equal to or more than the plate thickness of the work W. In the present embodiment, the piercing punch 64 is set in a fixed state regardless of the movement of the back pressure punch 63, but it is possible to positively make a hole in the blank material BL having a punched shape. It is also possible to activate it.

A mode in which the blank material BL punching step and the blank material BL opening step are performed in one stroke (one pressing operation) of the punch 61 will be described below. (1) Punching of blank material First, the work W having a substantially constant thickness sandwiched between the punch 61 and the die 62 is sheared by the pressing operation of the punch 61 and punched into a blank material BL having an appropriate shape. At this time, since the piercing punch 64 is provided in a state in which the die 62 is inserted (sunk) or more into the plate thickness dimension of the blank material BL from the surface holding the work W.
At the stage where the blank material BL has been punched out, the piercing punch 64 does not act on the blank material BL, and the holes are in an unopened state (see FIG. 3B).

(2) Opening of holes After the blanking of the blank material BL is completed, the blank material BL is further pressed by the punch 61 and pushed into the die 62, as shown in FIG. 3C. At this time, since the piercing punch 64 is set in a fixed state regardless of the operation of the back pressure punch 63, the piercing punch 64 relatively presses the blank material BL, and the pin hole 27 is formed in the blank material BL. Etc. are opened. Therefore, at the time of punching, the punch 61 mainly plays the role of the counter pressure punch. When the hole is opened, the tip of the pierce punch 64 and the scraps punched by the pierce punch 64 enter the pierce receiving hole 61 a of the punch 61. Then, the blank material BL perforated as described above has a die 62 by the action of the back pressure punch 63, for example, as the punch 61 is pulled up.
The punch 61 completes one stroke.

As described above, in the present embodiment, punching and punching are performed in one stroke of the punch 61. For example, punching of the ring 33 and bossing can be performed in one stroke. Yes (depending on model). Further, for example, punching and drawing (burring) of the rotating member 31 can be processed all at once. As described above, the constituent members of the exhaust guide assembly A can be efficiently manufactured by simultaneously performing a plurality of steps in one stroke.

[0031]

According to the present invention, the constituent members of the exhaust guide assembly A can be manufactured with high accuracy, and the tolerances after assembly (the tolerances in the assembled state) mainly caused by the dimensional accuracy of the individual parts are It can be suppressed as much as possible. Further, the durable life of the die member such as the punch 61 and the die 62 can be extended. Furthermore, when the taper surface TS is formed on the cutting edge portion C of the punch 61, when the work W is sheared, the stress acting particularly on the cutting edge portion C is orthogonal to the axial direction of the punch 61. Can be effectively dispersed in the direction, and the life of the mold member can be further extended. When a plurality of processes, for example, a blanking process of the blank material BL and a process of opening a hole in the blank material BL are performed by one pressing stroke of the punch 61, the constituent members of the assembly are The exhaust guide assembly A can be efficiently formed, and mass production of the exhaust guide assembly A can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view (a) showing a VGS type turbocharger incorporating an exhaust guide assembly to which the present invention is applied, and an exploded perspective view (b) showing the exhaust guide assembly.

FIG. 2 is an explanatory diagram showing a punch having a tapered surface on a cutting edge portion.

FIG. 3 is a cross-sectional view showing, step by step, an operation mode in which the punching step of the blank material shape and the step of forming a hole in the blanked blank material are performed by one pressing stroke of the punch.

[Explanation of symbols]

1 variable wings 2 turbine frame 3 variable mechanism 6 punching type 11 wings 12 Shaft 13 Tapered part 14 Tsubabe 15 Reference plane 21 frame segments 22 Holding member 23 Flange 23A Flange (small) 23B Flange (large) 24 Boss 25 receiving hole 26 Caulking pins 27 pin hole 31 Rotating member 32 transmission member 32A drive element 32B passive element 33 ring 61 punch 61a Pierce receiving hole 62 dice 63 Reverse pressure punch 64 Piercing Punch A Exhaust guide assembly BL blank material C cutting edge (Punch 61) G exhaust gas h blade height S Shoulder (of dice 62) T exhaust turbine TS taper surface (Punch 61) W work

Claims (3)

[Claims] 1. A plurality of variable blades are rotatably held at an outer peripheral position of an exhaust turbine, and a relatively small amount of exhaust gas discharged from an engine is appropriately narrowed down by the variable blades to amplify the speed of the exhaust gas. A VGS-type turbo that rotates the exhaust turbine with the energy of the exhaust gas and sends air above the naturally aspirated air to the engine with a compressor directly connected to this exhaust turbine so that the engine can deliver high output even at low speed rotation. When manufacturing the components of the exhaust guide assembly that is built into the charger, punching, drawing, coining, bossing, bending, forging, headers, caulking, and ironing are performed on the metal material that is the work mainly by punches and dies. , One or more of the rolling processes are performed to form the component member of the desired shape. In law, to the desired shape of the workpiece, in accordance with the processing techniques to be applied to the workpiece, the material of the punch and die, hardness, characterized in that it is adapted to apply to analyze optimized selection of toughness VG
A method for manufacturing constituent members of an exhaust guide assembly in an S type turbocharger. 2. The VGS type turbocharger according to claim 1, wherein the punch has a tapered surface on the cutting edge portion to disperse the stress applied to the cutting edge portion when the work is sheared. Of manufacturing a constituent member of an exhaust guide assembly in. 3. When the work is formed into a member having a desired shape, a blanking step and a punching step when a hole is opened in the punched blank material are included.
3. The V according to claim 1, wherein the punching process is performed by one pressing stroke of the punch.
A method of manufacturing constituent members of an exhaust guide assembly in a GS type turbocharger.