JP2003049659A - Manufacturing method for variable vane in vgs(variable geometry system) type turbocharger and variable vane manufactured by same method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new manufacturing method greatly suppressing shaft extension caused by a rolling while supposing that the shaft part of a preform to be an original form of a variable vane is formed by the rolling. SOLUTION: The metal preform to be the original form of the variable vane 1 is used as a starting material and the shaft part formed part of the preform is rolled and formed into the shaft part 12. The shaft part 12 is provided with a fitting part 16 to be turnably fitted into a receiving hole 25 in a turbine frame positioned in the outer circumference of an exhaust turbine T. The variable vane is characterized in that the fitting part 16 is provided with a rolling required part 17 and non-rolling part 18 having a slightly narrower diameter than that of the rolling required part 17 and that the rolling of the shaft part 12 is performed in the rolling required part 17 alone.

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, the present invention relates to a novel manufacturing method capable of manufacturing a variable blade to be incorporated in this one without cutting a raw material which is a prototype of the variable blade.

[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. This is a device in which a small exhaust flow rate is narrowed down by variable blades (blades), the speed of exhaust is increased, and the work of the exhaust turbine is increased, so that high output can be exhibited even at low speed rotation. Therefore, the VGS type turbocharger requires a variable blade variable mechanism and the like, and the peripheral components also have to be more complicated in shape and the like than the conventional ones.

When manufacturing a variable blade for such a VGS type turbocharger, the blade portion and the shaft portion are integrally formed by a precision casting method typified by lost wax casting or a metal injection molding method. There is a method of forming the formed metal material (form material that is the original shape of the variable blade), and then performing post-processing such as rolling on the shaft portion of the shape material to form a desired diameter. By the way, there is also a method of cutting the shaped material appropriately and finally finishing the wing and the shaft into desired shapes and dimensions, and it was worthy enough to be adopted in the trial production stage where the number of manufactured products is extremely small.

However, the variable blade, which is required to have high heat resistance, oxidation resistance, etc., is a material that is difficult to cut itself and requires a great amount of time for cutting. Therefore, cutting is not always an efficient method. Was not. In addition, about 10 to 15 variable blades are required for one turbocharger, so if the actual monthly production of about 30,000 vehicles is to be mass-produced, 300,000 to 450,000 variable blades will be manufactured per month. It was necessary, and the cutting process was not enough to deal with it (the cutting process was limited to about 500 pieces per day). For this reason, when mass-producing variable blades, it is necessary to eliminate cutting work from the working process as much as possible, and when processing the shaft portion, rolling has been the mainstream.

By the way, the variable blade is fitted in a frame member provided on the outer periphery of the exhaust turbine and is rotatably held, and the shaft portion of the variable blade can be rolled over substantially the entire length. There were many. That is, the shaft portion of the variable blade is generally entirely rolled, including the fitting portion that is inserted into the receiving hole of the frame member. However, in the method of rolling the entire shaft in this way, the axial elongation that accompanies the rolling tends to increase. In some cases, the rolling may be performed to correct the axial length extending in the longitudinal direction. After that, the shaft had to be cut. Of course, even the cutting work for such correction is a time-consuming work as described above, which is a cause of impairing the mass productivity of the variable blades, and therefore a manufacturing method for suppressing the axial elongation due to rolling is required. Was there.

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 has been earnestly desired.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such a background, and it is premised that the shaft portion of the raw material is processed by rolling, and This is a technical subject for the production method of a new variable blade that significantly suppresses the elongation.

[0009]

That is, a method for manufacturing a variable vane in a VGS type turbocharger according to a first aspect of the present invention comprises a shaft portion which is a center of rotation and a vane portion which substantially regulates a flow rate of exhaust gas. The relatively small amount of exhaust gas emitted from the engine is appropriately narrowed down, 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 more than natural intake air. In order to manufacture a variable blade to be incorporated into a VGS type turbocharger that enables the engine to exhibit a high output even at low speed rotation, the variable blade integrally includes a blade portion and a shaft portion. The starting material is a metal material to be the original shape of the variable blade, and the shaft portion is formed by rolling the shaft forming portion of the material. The shaft portion has a fitting portion that is rotatably fitted into the receiving hole of the frame member located on the outer periphery of the exhaust turbine, and the fitting portion includes the rolling required portion and the rolling required portion rather than the rolling required portion. With a non-rolled portion having a small diameter, rolling on the shaft portion is characterized in that it is applied only to this rolling required portion. According to this invention, since the variable blade is rolled only on the rolling-required portion of the fitting portion to be inserted into the frame member, compared with the case where the entire shaft portion including the fitting portion is rolled. Axial elongation due to rolling is significantly suppressed. For this reason, after the rolling, the cutting work that is sometimes performed to correct the axial elongation can be eliminated, and the variable blades can be efficiently mass-produced.

According to the method for manufacturing a variable blade in a VGS type turbocharger of claim 2, in addition to the requirements of claim 1, the fitting portion of the variable blade sandwiches a non-rolled portion and both ends thereof. It is characterized in that it has a rolling required part. According to the present invention, since the rolling required portion is formed at both ends of the fitting portion so as to sandwich the non-rolling portion, after the rolling, the rolling required portion is smooth just inside the receiving hole. Has the function of maintaining a smooth sliding state. Therefore, the rotation of the variable vanes is further stabilized, which contributes to the performance of the turbocharger, that is, the reliable control of the exhaust gas flow rate.

According to a third aspect of the present invention, in addition to the requirements of the first or second aspect, the method for manufacturing a variable vane in a VGS type turbocharger is the rolling-required portion of a fitting portion formed in the base material. The step size between the rolling part and the non-rolling part is set larger than the rolling allowance of the rolling requiring part, and when rolling, part of the metal material of the rolling allowance part is It is characterized by being made to flow to the rolling part. According to this invention, a part of the metal material of the rolling required part is
During rolling, the fluid flows to the non-rolled portion side so as to be guided by the step, so that axial elongation associated with rolling is further suppressed.

A method of manufacturing a variable blade in a VGS type turbocharger according to a fourth aspect of the present invention is the method according to the first aspect of the present invention.
In addition to the requirements described in 2 or 3, the step size between the rolling required portion and the non-rolling portion formed in the base material is about 0.1 m.
In addition to being set to about m, the rolling allowance of the rolling required portion is set to about 0.05 mm or less. According to the present invention, it is possible to make a specific setting that suppresses the axial elongation to an extremely small range during rolling.
By the way, when the whole shaft is rolled, for example, about 0.1-0.3
It has been confirmed by the applicant of the present invention that the axial elongation of about mm is stabilized by the rolling with the above dimension setting, and the substantial axial elongation is stabilized at almost zero.

The variable blades in the VGS type turbocharger according to claim 5 include a shaft portion rotatably held by a frame member at an outer peripheral position of the exhaust turbine,
It has a blade portion that substantially regulates the flow rate of exhaust gas, appropriately narrows the relatively small amount of exhaust gas discharged from the engine, amplifies the speed of exhaust gas, and rotates the exhaust turbine with the energy of exhaust gas. A variable blade installed in a VGS type turbocharger, which allows a compressor directly connected to a turbine to send air more than naturally aspirated to the engine so that the engine can exhibit high output even at low speed rotation. The shaft portion is such that the fitting portion to be fitted into the frame member comprises a rolling required portion and a non-rolling portion having a diameter slightly smaller than the rolling required portion, and the shaft portion has the above-mentioned claim 1, 2, It is characterized by being rolled and manufactured by the manufacturing method described in 3 or 4.
According to the present invention, it is possible to supply to the market variable blades having a high quality level in which the axial elongation that is inevitably caused by rolling is suppressed as much as possible. Also, due to the fact that axial elongation can be significantly suppressed,
You can eliminate the cutting work that you might have done to correct axial elongation. Therefore, it is possible to eliminate all the time-consuming cutting processes from the variable blade machining process, which makes the mass production of variable blades more realistic.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments. In the description, the variable vane 1 will be described together with the exhaust guide assembly A in the VGS type turbocharger to which the variable vane 1 according to the present invention is applied, and then the variable vane 1 according to the present invention.
The manufacturing method of 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. Each component will be described below.

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 provided, 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 fixed to the variable mechanism 3 described later by crimping or the like, and as an example, FIG.
As shown in FIG. 2, the plane in which the shaft portion 12 is cut out in a facing manner is formed with a substantially constant inclination with respect to the blade portion 11.

The variable vane 1 according to the present invention is formed by first forming a metal material (hereinafter referred to as a blank W) that integrally includes the blade 11 and the shaft 12 before the completion. Appropriate processing is performed on W to realize the desired shape and dimensional accuracy, and the variable blade 1 as a finished product is obtained. Here, each part of the blank W in which the wing part 11 and the shaft part 12 are finally formed is respectively referred to as a wing part forming part 11a and a shaft part forming part 12a.
It is defined as In the present invention, especially the shaft portion 12 of the variable vane 1 is machined to have a desired diameter by rolling. At that time, the entire shaft portion 12 is not rolled, but as an example, FIG. As shown, the fitting portion 16 fitted into the turbine frame 2 (frame member of the exhaust turbine T)
Partially rolled. By such a method, the axial elongation of the variable blade 1 which is inevitably caused by rolling is suppressed.

As shown in FIG. 2 as an example, the fitting portion 16 of the shaft portion 12 constitutes a rolling required portion 17 to be rolled near both ends thereof, and the rolling required portion is provided. The non-rolled portion 18 that is not rolled is sandwiched between the members 17. Further, in the present invention, the rolling required portion 17
Due to the fact that only the rolled material is rolled, the rolling-required portion 17 is formed to have a diameter slightly larger than that of the non-rolled portion 18, especially in the case of the blank W. The step difference between the forged portion 17 and the non-rolled portion 18 is set to about 0.1 mm. Since the rolling-required portion 17 is located near both ends of the fitting portion 16, the rotation of the variable blade 1 is retained near both ends of the fitting portion 16, so that the rotation of the variable blade 1 is prevented. Make it more stable.

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 at equal intervals. Further, the holding member 22 is formed in a disk shape having an opening in the central portion 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 caulking pins 26 are provided at four places on the outer peripheral portion of the receiving hole 25 as an example.
The dimension between both members is maintained by. Here, the holes formed in the frame segment 21 and the holding member 22 to receive 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 variable vane 1 according to the present invention is applied is configured as described above, and a method for manufacturing the variable vane 1 will be described below. (1) Step of Preparing Forming Material This step is a step of preparing a metal forming material W which is a prototype of the variable blade 1 by integrally including the blade forming portion 11a and the shaft forming portion 12a. According to the present invention, the variable blade 1 is not rolled as a whole but only the rolling-required portion 17 of the fitting portion 16 that is received by the turbine frame 2. The material W to be rolled is formed between the rolling-required portion 17 and the non-rolled portion 18, and the rolling-required portion 1
A step (for example, about 0.1 mm) is formed to make 7 convex. In forming such a blank W, an appropriate method such as precision casting, metal injection molding, blank material punching, or the like can be applied, and these methods will be briefly described below.

(A) Precision casting For example, lost wax casting, which represents a precision casting method, reproduces a target product (variable blade 1 in this case) in a wax model almost faithfully in shape and size. After coating the surrounding area with a refractory material, the brazing part inside is melted out to obtain only the refractory material (coating material), and casting is performed using this as a mold. As described above, in the precision casting, the casting product (form material W) can be reproduced with high accuracy by forming the mold almost exactly as intended. However, in the present embodiment, heat resistant steel (alloy) is used for casting.
A virgin material containing as a main material is applied, and the amount of C (carbon), Si (silicon), and O (oxygen) contained is optimized, for example, the weight% of each of C, Si, and O is 0.05. ~
By setting the content to 0.5%, 0.5 to 1.5%, or 0.01 to 0.1%, it is possible to improve the molten metal flowability and further improve the dimensional accuracy of the cast product. Is possible. Further, for example, after pouring, by quenching the metal material cast together with the mold, the time until the mold is crushed is shortened, the solidified grains of the raw material W are miniaturized, and in the subsequent rolling process, it is sharpened. Edge (Shaft part 1 is formed by rolling the shaft part 12
(2) It is also possible to appropriately take technical measures to make it difficult for the metal material on the surface 2 to cause plastic flow and to generate an acute angle portion formed in a protruding state from the tip end portion of the shaft portion 12.

(B) Metal injection molding In this method, a binder (mainly an additive for binding metal powders to each other, which is a mixture of polyethylene resin, wax and phthalate ester) is kneaded with a metal powder as a material. It is a method in which, after imparting plasticity, it is injected into a mold to form a desired shape, the binder is removed, and then the metal is sintered. The (form material W) is obtained. At this time, in order to generate small and uniform independent bubbles (spherical gaps between metal particles), sintering is performed for about 30 minutes to 2 hours, or the molded product is subjected to HIP (Hot Isostatic).
Abbreviation of Pressing; hot isostatic pressing) can be performed to improve the bulk density of the molded product. Further, it is also possible to appropriately take technical measures to make the shape of the metal powder spherical and fine by air atomization, water atomization, or the like as much as possible to improve the high temperature rotary bending fatigue property of the raw material W.

(C) Punching of blank material This method is a volume (volume of metal material) that can realize the target variable blade 1 from a strip steel or the like having a substantially constant thickness (about 4 mm as an example). In this method, a blank material punched so as to have the Of course, in the punching process, since the punching direction is usually straight, the cross section of the shaft portion 12, for example, can be formed only by the punching process.
It is impossible to form a substantially circular shape, and the shaft portion forming portion 12a of the blanked blank material generally has a substantially square cross section. For this reason, after the punching step and before shifting to the rolling step, for example, the shaft portion forming portion 12a having a substantially rectangular cross section is subjected to forging or coining to form a substantially circular cross section. Is. That is, substantially, the stamping step and the shaping step can obtain the raw material W having the same degree as that of precision casting or metal injection molding. When changing the cross-sectional shape in the molding process, corner R (fillet processing) or chamfering processing is applied to the corners of the stamped blank material (form material W) such as the shaft forming portion 12a. A technical device for making the shape closer to a completed shape such as a circular shape can be appropriately adopted. This prevents a dead metal flow state of the metal material and promotes smooth plastic flow of the metal material in the substantial modeling process. Incidentally, in the modeling step, the wing portion 11 can be simultaneously formed into a desired shape.

(2) Shaft Rolling Step After the raw material W, which is the original shape of the variable blade 1, is formed by an appropriate method in this manner, the shaft forming portion 12a of the raw material W is formed.
Is processed into a desired diameter by rolling. At this time, the rolling-required portion 17 formed in a protruding state with respect to the non-rolled portion 18
However, as shown in FIG. 3 as an example, a pair of dies (rolling rollers) D presses the material W and the dies D relatively to each other while substantially rolling the dies. As shown in FIG. 3 as well, the rolling required portion 17 and the non-rolling portion 18
When the step difference between and is about 0.1 mm, the rolling allowance of the rolling required portion 17 in this step is set to 0.05 mm or less as an example. Therefore, even after the rolling, the rolling required portion 1
7 and the non-rolled portion 18 still have a step difference (about 0.05 mm) obtained by subtracting the rolling allowance from the step size. The metal material positioned at the position flows so as to be guided to the non-rolled portion 18, and further suppresses the axial elongation due to the rolling.

Here, the relationship between the rolling allowance of the rolling-required portion 17 and the axial elongation is shown in FIG. 4 as an example. From this figure, if the rolling allowance is approximately 0.065 mm or less, it is substantially It can be seen that the specific axial elongation is stable at 0 and hardly occurs.
Therefore, in the present embodiment, considering some margin,
The rolling allowance is set to 0.05 mm or less.
In this figure, the straight line that passes through the point where the axial elongation is about 0.015 mm when the rolling allowance is 0.1 mm is the reference for almost both relationships, and the range of variations in the upper and lower hatched parts is shown. There is. Note that the relationship (reference) between the rolling allowance and the axial elongation shown in this figure does not pass through the origin, which means that the metal material of the rolling-required portion 17 is exclusively non-rolled by rolling as described above. This is because the substantial axial elongation is suppressed to 0 up to a certain rolling allowance (approximately 0.065 mm on the graph) due to the fluid flowing so as to be pushed away to the forming portion 18.

As described above, by rolling only the rolling-required portion 17, the axial elongation can be remarkably reduced and stabilized at almost 0. Therefore, conventionally, in order to correct the axial elongation, after rolling, It is possible to eliminate the cutting process that was sometimes performed.
Therefore, it is possible to completely eliminate the cutting process that requires a great deal of time from the processing step of the variable blade 1, which makes the mass production of the variable blade 1 at a high quality level more realistic.

The metal material that has flowed from the rolling required portion 17 to the non-rolling portion 18 side is microscopically viewed as if the rolling required portion 17 and the non-rolling portion are as shown in FIG. 3 as an example. It is formed in a tapered state so as to overlap with 18, and the metal material of this portion is particularly denoted by a surplus portion e. The excess thickness portion e formed so as to flow from the rolling required portion 17 to the non-rolled portion 18 and overlap with both rolling portions has a larger diameter than the rolling required portion 17 due to the formation process. Not,
Therefore, when the variable blade 1 rotates, the excess thickness portion e does not hinder this rotation at all. Furthermore, in this embodiment,
Roll-requiring portions 17 are formed near both ends of the fitting portion 16 with a non-rolling portion 18 interposed therebetween, and the roll-requiring portions 17 are located just inside the receiving hole 25 formed in the frame segment 21. Therefore, in order to substantially maintain the smooth rotating state of the variable blade 1, the variable blade 1 can be rotated more reliably and stably.

(3) After the rolling of the working shaft portion 12 of the blade portion and the variable blade as a whole is completed, the raw material W (in this state, the raw material W substantially shows the completed state of the variable blade 1). )
The blade height h is appropriately polished, or overall barrel polishing or the like is performed to form the variable blade 1 having a desired shape and dimensional accuracy.

[0032]

According to the first aspect of the present invention, the shaft portion 12 (shaft portion forming portion 12a) of the variable vane 1 is substantially rolled because only the rolling required portion 17 is rolled. Axial elongation is almost 0
Can be stabilized. For this reason, the cutting process can be completely eliminated from the manufacturing process of the variable vane 1, and the mass production of the variable vane 1 becomes a reality.

According to the second aspect of the invention, since the rolling required portions 17 are formed at both ends of the non-rolling portion 18, the non-rolling portions 18 allow the variable blade 1 to smoothly slide. Can be maintained. Therefore, the flow control of the exhaust gas G can be performed accurately and surely, which contributes to the performance improvement of the variable vane 1.

Further, according to the third aspect of the invention, the metal material that is fluidized by rolling is retained between the rolling required portion 17 and the non-rolled portion 18 to form the extra thickness portion e. Therefore, the excess thickness portion e is suppressed from growing in the axial length direction, and the axial extension is effectively suppressed.

According to the invention described in claim 4, it is possible to realize a specific setting that stabilizes the substantial axial elongation to almost zero.

Further, according to the invention of claim 5, the prior art
It is possible to stably supply the variable blade 1 having a high quality level in which the axial elongation due to rolling is almost zero to the market.

[Brief description of drawings]

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

FIG. 2 is a front view and a left side view showing a variable vane according to the present invention.

FIG. 3 is an explanatory diagram showing a state of a shaft portion before and after rolling.

FIG. 4 is a graph showing a relationship between a rolling allowance of a rolling required portion and axial elongation.

[Explanation of symbols]

1 variable wings 2 turbine frame 3 variable mechanism 11 wings 11a Wing forming section 12 Shaft 12a Shaft part forming part 13 Tapered part 14 Tsubabe 15 Reference plane 16 Fitting part 17 Rollable parts 18 Non-rolled section 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 A Exhaust guide assembly D dice e Extra thickness area G exhaust gas h blade height T exhaust turbine W material

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukio Takahashi             4-38-2 Fukuodai, Sodegaura-shi, Chiba Cosmo             Sodegaura No. 106 F-term (reference) 3G005 EA15 FA43 GB25 KA03 KA07

Claims (5)

[Claims] 1. A shaft having a center of rotation and a wing that substantially adjusts a flow rate of exhaust gas, and appropriately narrows a relatively small amount of exhaust gas discharged from an engine to amplify the speed of the exhaust gas. VGS type that rotates the exhaust turbine with the energy of the exhaust gas, and sends the air more than naturally aspirated to the engine by the compressor directly connected to this exhaust turbine, so that the engine can exhibit high output even at low speed rotation. In manufacturing a variable blade to be incorporated into a turbocharger of, the variable blade is integrally provided with a blade portion and a shaft portion, starting from a metal raw material which is a prototype of the variable blade, the shaft portion, The shaft portion forming portion of this raw material is formed by rolling, and the shaft portion is a fitting portion that is rotatably fitted into a receiving hole of a frame member located on the outer periphery of the exhaust turbine. In addition, the fitting portion has a rolling required portion and a non-rolling portion having a diameter slightly smaller than that of the rolling required portion, and the rolling on the shaft portion is performed only at this rolling required portion. A method for manufacturing a variable vane in a VGS type turbocharger, comprising: 2. The variable VGS turbocharger according to claim 1, wherein the fitting portion of the variable vane comprises a non-rolled portion and rolling portions at both ends thereof. Wing manufacturing method. 3. A step size between a rolling required portion and a non-rolling portion of a fitting portion formed on the base material is set to be larger than a rolling allowance of the rolling required portion, and The VG according to claim 1 or 2, wherein a part of the metal material of the rolling allowance portion is made to flow from the rolling required portion to the non-rolled portion on the small diameter side.
A method for manufacturing a variable blade in an S type turbocharger. 4. The step size between the rolling required portion and the non-rolling portion formed in the base material is set to about 0.1 mm, and the rolling allowance of the rolling required portion is About 0.05m
The method for manufacturing a variable blade in a VGS type turbocharger according to claim 1, 2 or 3, wherein the value is set to m or less. 5. A relatively small amount of exhaust gas discharged from an engine, comprising a shaft portion rotatably held by a frame member at an outer peripheral position of an exhaust turbine, and a blade portion for substantially adjusting a flow rate of exhaust gas. The gas is appropriately narrowed down, the speed of the exhaust gas is amplified, the exhaust turbine energy is used to turn the exhaust turbine, and the compressor directly connected to the exhaust turbine sends air above the naturally aspirated air to the engine. In a variable blade incorporated in a VGS type turbocharger capable of exhibiting a high output, the shaft portion of the variable blade has a fitting portion to be fitted into a frame member, and a rolling required portion and this rolling required portion. A non-rolled portion having a somewhat smaller diameter, wherein the shaft portion is rolled and manufactured by the manufacturing method according to claim 1, 2, 3 or 4. Variable wing.