JP2020537076A - How to balance the impeller for the exhaust gas turbocharger, the exhaust gas supercharger, and the rotating body assembly for the exhaust gas turbocharger - Google Patents

Abstract

The present invention relates to an impeller for an exhaust gas turbocharger. The impeller (1) is rotatably supported in the housing of the exhaust gas supercharger (3) about a rotation axis, and the impeller (1) includes an impeller hub (5). The impeller hub (5) includes an impeller back plate (6) and an impeller front plate formed on the side opposite to the impeller back plate (6). A plurality of impeller blades (4) extending between the impeller front plate and the impeller back plate (6) are formed on the hub (5), and the plurality of impeller blades (4) are formed. The first impeller blade (7) of the first impeller blade (7) and the second impeller blade (8) of the plurality of impeller blades (4) adjacent to the first impeller blade (7). A balance adjustment mark (11) is formed in the inter-blade flow path (9) formed between the blades. According to the present invention, the balance adjustment mark (11) is formed in a substantially triangular shape. The present invention further relates to an exhaust gas turbocharger equipped with such an impeller and a method for adjusting the balance of a rotating body assembly for the exhaust gas turbocharger. [Selection diagram] Fig. 4

Description

The present invention includes an impeller for the type of exhaust gas turbocharger according to the premise part of claim 1, the exhaust gas supercharger according to claim 5, and the type described in the premise part of claim 6. Regarding how to balance the rotating body assembly for the exhaust gas turbocharger.

Patent Document 1 discloses a rotating body assembly including an impeller of an exhaust gas supercharger. The impeller is provided with a plurality of impeller blades provided on the impeller hub, and the impeller hub is provided with an impeller back plate and an impeller provided on the side opposite to the impeller back plate. It has a front part. Further, the impeller is provided with a curved balance adjustment mark on the impeller back plate.

Patent Document 2 describes a rotating body assembly having a balance adjustment mark, and the adjustment mark is formed in the shape of a vertical cross section of a pear. The balance adjustment mark of the shape of the vertical cross section of this pear consists of a main body portion and a bulging portion considerably smaller than this main body portion. The problem here is that the main body is located closer to the center of the impeller and the bulge is located closer to the outer peripheral edge of the impeller. That is, the width of the inter-blade flow path becomes narrower as it approaches the center of the impeller, whereas the formation of the balance adjustment mark in this way is a limiting factor in the material removal process for eliminating the imbalance. It has become.

Further, it is also known that a balance adjustment mark is formed on the impeller hub between the impeller back plate and the impeller front plate. In this case, the balance adjustment mark is formed on the inter-blade flow path formed between the two impeller blades, that is, on the bottom surface of the inter-blade flow path. However, at this formation position, it may not be possible to remove sufficient mass of material. This is because the balance adjustment mark is preferably formed at a position close to the maximum diameter of the impeller, whereas the wall thickness of the impeller is generally very thin near the maximum diameter. Therefore, in the worst case, the rate of defective products of the impeller will increase.

When the balance adjustment mark is formed by milling, a high material stress is generated in the bottom surface region of the balance adjustment mark, that is, in the vicinity where the wall thickness of the impeller is minimized. This means that a sufficient amount of material is removed in the thickness direction of the impeller in order to reduce or eliminate the imbalance.

German patent application published DE 10 2010 048 099 A1 German patent application published DE 10 2015 219 374 A1

An object of the present invention is to provide a method for balancing an impeller for an improved exhaust gas turbocharger, such an exhaust gas turbocharger, and a rotating body assembly for the exhaust gas turbocharger. The purpose is to enable better balance adjustment.

The above object is an impeller for an exhaust gas turbocharger having the features described in claim 1, an exhaust gas turbocharger having the features described in claim 5, and the features described in claim 6. Achieved by a method of balancing the rotating body assembly for an exhaust gas turbocharger equipped with. The dependent claims describe a particularly advantageous configuration example with suitable and important structural features of the present invention.

The first aspect of the present invention relates to an impeller for an exhaust gas turbocharger. The impeller is rotatably supported around a rotation axis in the housing of the exhaust gas supercharger. The impeller comprises an impeller hub, which comprises an impeller back plate and an impeller front plate formed on the opposite side of the impeller back plate. A plurality of impeller blades are formed so as to extend between the impeller hub and the impeller back plate. Between the blades formed between the first impeller blade of the plurality of impeller blades and the second impeller blade of the plurality of impeller blades adjacent to the first impeller blade. A balance adjustment mark is formed on the flow path. According to the present invention, the balance adjustment mark has a substantially triangular shape, and is preferably formed in a triangular shape.

The advantage is that a larger balance adjustment mark can be formed without increasing the minimum wall thickness dimension of the impeller, which is possible by the material removal process for forming the balance adjustment mark. This is because is performed three-dimensionally. In other words, the material removal process is also performed in the axial direction of the impeller, that is, in the depth direction of the impeller or the thickness direction of the impeller, in the circumferential direction of the impeller, or It is also done in the radial direction of the impeller. Since the material removing process is performed in these three directions, the amount of material that can be removed without lowering the strength of the impeller during operation is increased as compared with the case of forming the conventional balance adjustment mark. This means that the rate of defective products in the manufacture of impellers can be significantly reduced.

The part where the maximum stress acts when milling is applied is the boundary part of the cutting area by milling, and in such a part, the wall thickness of the impeller is thicker than the central part of the balance adjustment mark. For example, a point-shaped balance adjustment mark is formed in a portion of the impeller where the wall thickness is thin.

By forming the balance adjustment mark having the above-described configuration on the impeller, the rotating body assembly including the impeller and the connecting rotating shaft coupled to the impeller so as to rotate integrally with the impeller can be extremely formed. A good balance adjustment can be made so that the rotating motion of the rotating body assembly during operation of the exhaust gas supercharger can be very good, at least with almost no rotational imbalance.

According to one configuration example, one edge portion of the balance adjustment mark is formed so as to extend in the circumferential direction. The advantage of this configuration is that the bottom surface of the flow path of the inter-blade flow path can be optimally used, and it is possible that the shape of the bottom surface of the flow path is from the outer peripheral edge of the impeller of the impeller. This is because it has a substantially triangular shape in which the width gradually narrows as it approaches the center of the impeller of the impeller. That is, the remaining two edge portions of the balance adjustment mark formed in a substantially triangular shape are the centers of the impeller in order to perform the necessary material removal processing when matching the shape of the existing flow path bottom surface. It becomes possible to extend toward.

In general, the stress generated in the impeller when forming the balance adjustment mark is smaller in the vicinity of the impeller blades, so it is advantageous to form the balance adjustment mark in the vicinity of the impeller blades. Is.

According to another configuration example, the bottom surface region of the balance adjustment mark is smaller than the free surface region of the balance adjustment mark. In other words, the edge portion of the balance adjustment mark is formed so as to taper toward the impeller back plate. The advantage of this configuration is that a rounded transition portion having at least no sharp corner is formed between the bottom surface region of the balance adjustment mark and the edge portion, so that the stress of the recess portion is relaxed. It is in.

The balance adjustment mark according to the present invention is applied to a compressor impeller whose wall thickness from the impeller back plate to the impeller front plate is thinner than that of the turbine impeller, and particularly on the outer peripheral edge of the impeller. Especially suitable for use. The thin wall thickness of the impeller not only helps to reduce the mass moment of inertia of the impeller, but also contributes to the reduction of material cost, and it is possible to manufacture a compressor impeller at low cost. It becomes. Further, since the balance adjustment mark is formed in a substantially triangular shape, even if the balance adjustment mark is extended to a low depth, a sufficient amount of material is required to manufacture an impeller without imbalance. It can be removed from around the balance adjustment mark.

A second aspect of the present invention relates specifically to an exhaust gas supercharger for an internal combustion engine, which exhaust gas supercharger comprises a rotating body assembly rotatably supported within a housing. The rotating body assembly includes a rotating shaft and at least one impeller according to the present invention coupled to the rotating shaft so as to rotate integrally with the rotating shaft. A suitable configuration example of the first aspect of the present invention is also a suitable configuration example of the second aspect of the present invention, and vice versa.

The rotating body assembly of the exhaust gas supercharger is excellent in quietness of rotation because the balance of the impeller is well adjusted and therefore the balance of the rotating body assembly is well adjusted. As a result, the operating efficiency of the exhaust gas supercharger is improved, and the service life of the exhaust gas supercharger is extended.

A third aspect of the present invention relates to a method for adjusting the balance of a rotating body assembly rotatably supported in a housing of an exhaust gas supercharger, and particularly to a method for adjusting the balance of an impeller of the rotating body assembly. In the balance adjusting method, the impeller includes a plurality of impeller blades provided on the impeller hub of the impeller. A bottom surface of the flow path is provided between the first impeller blade of the plurality of impeller blades and the second impeller blade of the plurality of impeller blades adjacent to the first impeller blade. An inter-blade flow path is formed, and a balance adjustment mark is formed on the bottom surface of the flow path. According to the present invention, the balance adjustment mark according to any one of claims 1 to 4 is formed during the high-speed balance adjustment work.

One of the advantages of this method of adjusting the balance of the rotating body assembly is that by using the method of high-speed balance adjusting work, not only the individual impellers can be individually balanced, but also the balance of the entire rotating body assembly can be adjusted. The adjustment can also be completed in a single work process, which can significantly reduce the work time for balancing the rotating body assembly. Further, even if a residual imbalance is present in the turbine impeller, the residual imbalance can be corrected by forming a balance adjustment mark on the compressor impeller by this method. Further, even when an imbalance occurs due to elastic deformation, the imbalance can be corrected.

The balance adjustment mark can be formed at low cost by using a processing method for removing the material, and it is particularly preferable to use milling processing. As an advantageous method, a ball head-shaped tool is used, in which the edges that intersect each other and / or the surfaces that intersect each other, the connection and / or the transition are rounded. Can be formed into. The advantage is that the stress in the recesses is significantly relieved, which causes the connections and / or transitions to be rounded, for example in milling with a cylinder head mill. Defects in impeller or rotating body assembly due to the formation of no acute angles can be reduced.

Further advantages, features, and detailed configurations of the present invention will become apparent with reference to the description of preferred embodiments set forth below and with reference to the accompanying drawings. The various features and combinations of those features mentioned in the above description, and the various features and combinations of those features mentioned and / or shown in the drawings in the following description in connection with the accompanying drawings, are those. Not only can it be used in the combinations as shown in the description or drawings, but it can also be used in different combinations, and individual features can be used independently, as such. Even if the features are used, it does not deviate from the scope of the present invention. The same reference code is assigned to the same or functionally the same element.

It is a perspective view which showed a part of the impeller according to the conventional example. It is a perspective view which showed a part of the impeller according to another conventional example. It is a perspective view which showed a part of the impeller according to 1st Example of this invention. It is a perspective view which showed a part of the impeller according to the 2nd Example of this invention. It is a perspective view which showed a part of the impeller according to the 3rd Example of this invention. It is a perspective view which showed a part of the impeller according to the 4th Example of this invention.

FIG. 1 shows the impeller 1 of the rotating body assembly 2 for the exhaust gas supercharger 3 according to the conventional example. The impeller 1 is designed as a compressor impeller. In addition to the impeller 1, the rotating body assembly 2 further includes a turbine impeller (not shown), and the turbine impeller has a rotating shaft (not shown) so as to rotate integrally with the compressor impeller 1. It is connected to the compressor impeller 1 via.

The rotating body assembly 2 is rotatably supported in the bearing structure portion (not shown) of the exhaust gas supercharger 3 about the rotation axis (not shown) of the rotating body assembly 2. The turbine impeller is rotatably housed in an exhaust flow section (not shown) formed as a flow path of the exhaust gas supercharger 3. The exhaust gas supercharger 3 is connected to an internal combustion engine (not shown), fluid can be communicated between the exhaust gas supercharger 3 and the internal combustion engine, and the exhaust gas of the internal combustion engine (not shown) Is supplied to the turbine impeller by flowing in through the inflow pipeline (not shown) of the exhaust flow section, and the turbine impeller rotates.

By being connected to the compressor impeller 1 so as to rotate integrally via a rotation shaft, the compressor impeller 1 is rotatably housed in the intake air flow section (not shown) and rotates in the same manner as described above. It is forced to inhale air and compress it. The compressed air is supplied to the internal combustion engine through an outflow pipe (not shown) of the intake flow section.

The compressor impeller 1 is provided with a plurality of impeller blades 4 for sucking air, and the plurality of impeller blades 4 are provided on the impeller hub 5 of the compressor impeller 1. The impeller hub 5 includes an impeller back plate 6 and an impeller front plate (not shown) formed on the side opposite to the impeller back plate 6. The plurality of impeller blades 4 are provided on the impeller hub 5 so as to extend between the impeller front plate and the impeller back plate 6. A blade having a flow path bottom surface 10 between two impeller blades adjacent to each other among a plurality of impeller blades 4, that is, between the first impeller blade 7 and the second impeller blade 8. An inter-blade flow path 9 is formed, and air flows along the inter-blade flow path 9. Further, the impeller 1 can rotate about a rotation axis (not shown).

A balance adjustment mark 11 is formed on the bottom surface 10 of the flow path of the compressor impeller 1 so that the rotating body assembly 2 can rotate with a high degree of quietness. The balance adjustment mark 11 formed on the impeller of the conventional example shown in FIG. 1 is formed in a dot shape.

What is shown in FIG. 2 is an impeller according to another conventional example. The balance adjustment mark 11 formed on the impeller has an elongated and slightly curved shape.

FIG. 3 shows a balance adjustment mark 11 according to the first embodiment of the present invention, and the balance adjustment mark 11 is formed in a substantially triangular shape. The balance adjustment mark 11 includes a first edge portion 12, a second edge portion 13, and a third edge portion 14, and these three edge portions are connected to each other by three connecting portions 15. ing. The connecting portions 15 are formed in a curved shape, whereas each of the three edge portions 12, 13 and 14 is formed in a more linear shape as compared with the connecting portions 15.

The substantially triangular shape of the balance adjustment mark 11 mainly means that the outer peripheral edge of the balance adjustment mark 11 is formed in a substantially triangular shape. However, it may also mean that the extension portion T of the balance adjustment mark 11 in the depth direction has a substantially triangular shape. Alternatively, it may also mean that the balance adjustment mark 11 is formed in a substantially triangular shape in all three dimensions, that is, in the shape of a triangular pyramid (tetrahedron). In any of these cases, the triangle may be an equilateral triangle, an unequal-sided triangle, or an isosceles-sided triangle.

In order to form the balance adjustment mark 11 during the so-called high-speed balance adjustment work, the tool for material removal may be moved to form the balance adjustment mark 11, or the entire impeller 1 or rotating body assembly 2 may be formed. It may be formed by moving one side. If the balance adjustment mark 11 to be formed has a linear shape, it is convenient to move the tool. On the other hand, in order to form the balance adjustment mark 11 according to the present invention, It is convenient to move the entire impeller 1 or the rotating body assembly 2 and also move the tool to form the structure.

When using a so-called high speed balancing machine, the rotating body assembly is fastened to the high speed balancing machine as it is assembled to the bearing structure housing and has access to the impeller hub 5 for material removal processing. The direction to do is the axial direction. On the other hand, when a machine other than the high-speed balance adjustment machine is used, machining on the radiation axis is performed from a predetermined angle direction. In this case, access is provided to the area of the impeller hub 5 located further inward in the radial direction, which is the direction of the impeller back plate 6 where the stress is not so great, and it is possible to remove, for example, more material. ..

In order to make it possible to remove the material having a sufficient mass from the impeller so that the imbalance can be reduced or eliminated, the depth of the extension portion T of the balance adjustment mark 11 in the depth direction may be increased. Compared with the balance adjustment mark of the conventional example, the balance adjustment mark 11 having a substantially triangular shape can perform material removal processing three-dimensionally, so that a sufficient amount of material must be removed to eliminate the imbalance. Is possible.

The first edge portion 12 is a portion corresponding to the bottom edge of the balance adjustment mark 11, and is formed so as to extend in the circumferential direction U. Therefore, the tip portion 16 of the balance adjustment mark 11 faces the side opposite to the outer peripheral edge 17 of the impeller, that is, faces the center point of the impeller. Since it is formed in this way, the arrangement of the balance adjustment mark 11 is such that the width of the flow path bottom surface 10 gradually narrows as it approaches the center point of the impeller from the outer peripheral edge 17 of the impeller. The layout is practically suitable.

In the balance adjustment mark 11 according to the first embodiment shown in FIG. 3, the first edge portion 12 has a gently curved shape, whereby the shape of the balance adjustment mark 11 is changed to the outer peripheral edge 17 of the impeller. It has a shape that can be adapted to the degree of curvature of. However, the degree of curvature of the first edge portion 12 is much gentler than the degree of curvature of the connecting portion 15. Similarly, the shapes of the other two edge portions 13 and 14 are also gently curved, but the degree of curvature of these edge portions is also much gentler than the degree of curvature of the connecting portion 15. ..

FIG. 4 shows the balance adjustment mark 11 according to the second embodiment of the present invention. Compared with the balance adjustment mark 11 of the first embodiment, in the balance adjustment mark 11 of the second embodiment, the three edge portions 12, 13 and 14 are formed in a straight line, and the balance adjustment mark 11 is formed therein. The extending dimension of the circumferential direction U is larger.

By forming the connecting portion 15 in a curved shape, the stress of the recessed portion generated between the two edge portions intersecting with each other among the edge portions 12, 13 and 14 is relaxed. Furthermore, by forming each transition portion 19 formed between each of the edge portions 12, 13 and 14 and the bottom surface region 18 of the balance adjustment mark 11 into a rounded shape, the stress of the recess portion can be further increased. Is being relaxed. In other words, the bottom surface region 18 of the balance adjustment mark 11 is smaller than the opening region 20 of the balance adjustment mark 11, which is particularly the balance adjustment mark 11 according to the third embodiment shown in FIG. It is clear if you look at it. The opening region 20 of the balance adjustment mark 11 referred to here is a region extending over three edge portions 12, 13 and 14 on the surface of the bottom surface 10 of the flow path.

As a method for forming the balance adjustment mark 11, basically any method may be used as long as the material can be removed, that is, any kind of material removal processing method is used. Is possible. In particular, when the impeller 1 is designed as a turbine impeller, it is preferable to use grinding. It is also good to remove the material by laser processing. Alternatively, the balance adjustment mark 11 may be formed on the outer peripheral edge portion of the impeller 1 by cutting. Since the milling process is a low-cost and highly flexible processing method, it is a suitable method as a surface processing method, and is advantageous in terms of cost as compared with other processing methods.

The impeller 1 shown in FIG. 6 is an impeller designed as a compressor impeller, and includes a balance adjustment mark 11, which is formed by ball head milling. That is, the balance adjustment mark 11 is formed by milling using a ball head-shaped tool. If the balance adjustment mark is formed by this method, the connection portion 15 and the transition portion 19 are formed in a rounded shape in a simple process, so that in the process of forming the balance adjustment mark 11 using the material removal processing method. , No separate processing process is required.

Claims (8)

In the impeller for the exhaust gas supercharger
The impeller (1) is rotatably supported in the housing of the exhaust gas supercharger (3) about a rotation axis, and the impeller (1) includes an impeller hub (5). The impeller hub (5) includes an impeller back plate (6) and an impeller front plate formed on the side opposite to the impeller back plate (6). A plurality of impeller blades (4) extending between the impeller front plate and the impeller back plate (6) are formed on the hub (5), and the plurality of impeller blades (4) are formed. The first impeller blade (7) of the first impeller blade (7) and the second impeller blade (8) of the plurality of impeller blades (4) adjacent to the first impeller blade (7). In an impeller in which a balance adjustment mark (11) is formed in the inter-blade flow path (9) formed between them.
The impeller is characterized in that the balance adjustment mark (11) is formed in a substantially triangular shape. The impeller according to claim 1, wherein the balance adjustment mark (11) is formed so that one edge portion (12) thereof extends in the circumferential direction. The impeller according to claim 1 or 2, wherein the bottom surface region (18) of the balance adjustment mark (11) is smaller than the opening region (20) of the balance adjustment mark (11). The impeller according to claim 1, wherein the impeller (1) is a compressor impeller. In an exhaust gas supercharger for an internal combustion engine, a rotating body assembly (2) rotatably supported in the housing of the exhaust gas supercharger (3) is provided, and the rotating body assembly is connected. A rotating shaft and at least one impeller (1) coupled to the connected rotating shaft so as to rotate integrally with the connected rotating shaft are provided, and the impeller (1) is any one of claims 1 to 4. An exhaust gas supercharger characterized by being the impeller according to item 1. In the balance adjustment method of the rotating body assembly (2) rotatably supported in the housing of the exhaust gas supercharger (3).
The rotating body assembly (2) includes an impeller (1), and the impeller includes a plurality of impeller blades (4) provided on the impeller hub (5) of the impeller. , The first impeller blade (7) of the plurality of impeller blades (4) and the first of the plurality of impeller blades (4) adjacent to the first impeller blade (7). An inter-blade flow path (9) having a flow path bottom surface (10) is formed between the two impeller blades (8), and a balance adjustment mark (11) is formed on the flow path bottom surface (10). , In the balance adjustment method
A method characterized in that the balance adjustment mark (11) according to any one of claims 1 to 4 is formed during high-speed balance adjustment work. The method according to claim 6, wherein the balance adjustment mark (11) is formed by performing a material removal process. The method according to claim 6 or 7, wherein the balance adjustment mark (11) is formed by milling, and particularly by milling using a ball head-shaped tool.

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