JPS645649B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bladed rotating body such as a turbine rotor of a turbocharger for an automobile, and particularly to a technique for easily measuring unbalance thereof. The unbalance of a turbocharger's turbine rotor about its axis of rotation is generally measured using a horizontal microbalancer. The horizontal microbalancer has its bearings rotatably support the vicinity of both ends of the rotating shaft of the turbine rotor, and then a belt is suspended around the turbine rotor and the turbine rotor is rotated by the belt drive, thereby reducing the unbalance. It is measured as a vector quantity having a (quantity) and a direction. The magnitude of the unbalance (generally in g/cm) is determined by outputting the lateral vibration (displacement) of the microbalancer's bearing as a voltage using an electromagnetic pickup, and the direction of the unbalance (generally in degrees) is determined by the phase using a photo sensor. Detected by scanning. In this way, the unbalance is generally expressed as, for example, 75 degrees and 2 g.cm (the former number indicates the angle, and the latter number indicates the magnitude or amount, respectively).

In this way, the unbalance of the turbine rotor is measured, but in order to detect the direction of the unbalance, it is necessary to display the 0 degree phase of the turbine rotor. First, how this 0 degree phase was conventionally determined will be explained with reference to FIG.

Fig. 1 shows a typical shape of a turbine rotor, which has blades 3 and a rotating shaft 5, and is marked with a marker or paint, for example, black, at an appropriate position on the shaft 5 as shown by A or B. A line was drawn and its brightness was detected by the photo sensor 10, and the transition point between the brightness and darkness (the boundary line of magic or paint) was set as the 0 degree phase. However, this method had the following disadvantages.

The worker must draw each line.

Prior to drawing the lines, it is necessary to wash or clean the shaft of the turbine rotor.

When using paint, it must be allowed to dry after painting.

Since all of these drawbacks are factors that hinder automation, conventionally all of the above-mentioned operations have had to be performed manually.

The present invention aims to solve the drawbacks of the prior art,
A turbine rotor (generally a rotor with blades) that can easily and reliably display the 0 degree phase required for unbalance measurement without adding any extra manual processes such as wire drawing as described above in the manufacturing process of the turbine rotor. ).

Another object of the present invention is to obtain such a stable zero
An object of the present invention is to provide a method for manufacturing a turbine rotor (generally a rotating body with blades) that enables display of degree phase.

Preferred embodiments of the present invention will be described below with reference to the drawings.

In the following description, a turbine rotor for a turbocharger is used as an example of a rotor with blades, but the present invention is not limited to such a turbine rotor, and is generally applicable to blades or the like of a pump, fan, compressor, etc. It is applicable to a rotating body equipped with a blade member.

For convenience, the first protrusion 4A provided to provide a 0 degree phase will be described first, and the second protrusion 4B for offsetting the imbalance caused by this protrusion 4A will be described later.

FIG. 2 shows a front view of a turbocharger turbine rotor according to an embodiment of the invention.
The maximum outer diameter 3B of any one of the plurality of blades 3 (10 in the illustrated example) is provided with a protrusion 4A that protrudes by h in the radial direction, and the remaining nine blades The maximum outer diameter portion 3B has a cast surface, and only the projections 4A have a machined surface. The manufacturing process up to the embodiments of the present invention will be described below.

During the casting process, the turbine rough material of the turbine rotor is formed into h +
Let it protrude in the radial direction by α'(α' is the cutting allowance).
Thereafter, the shaft portion is attached to the turbine rough-shaped member of the turbine rotor by friction welding or the like.
FIG. 3 shows a state in which the machining of the shaft portion 5 has been completed. Of course, in this state, there is a machining allowance α on the small diameter portion 3A of the turbine rotor, and there is also a machining allowance α on the maximum outer diameter portion of one blade. 3B has a protrusion of h+α'. The dimension R shown in FIG. 3 is the nominal dimension of the maximum outer diameter of the remaining nine sheets.

Next, as shown in FIG.
A and the maximum outer diameter portion 3B are the two blade surfaces 21 and 22.
At the same time, a grinding process is performed using a tool (for example, a grindstone) 20 having a grinding wheel. At this time, the machining allowance is set to α in the radial direction for the small diameter portion 3A, and α′ in the radial direction for the maximum outer diameter portion 3B. Of course, in this embodiment, the small diameter part 3A and the maximum outer diameter part 3B are machined simultaneously, but if you accept the drawback that the number of grinding steps increases by one, the small diameter part 3A and the largest outer diameter part 3B can be machined separately. may be done.

Next, the reason why the protrusion height h after machining of the maximum outer diameter portion 3B in FIG. 4 occurs will be explained. In the present invention, after machining the maximum outer diameter portion, only the maximum outer diameter portion of one blade is processed, and the maximum outer diameter portions of the remaining blades must remain as cast surfaces. Furthermore, during the grinding process shown in FIG. 4, the tool 20 and the turbine rotor 41 are rotated about the rotation axes l _W and l _T , respectively. Maximum outer diameter part 3B of the current turbine rough profile
The nominal dimension (3rd session) R has dimensional variations such as R + r1 - r2, and furthermore, during the machining shown in Fig. 4,
There is variation in the positional accuracy of the tool 20 +P1 -P2.
From the above, in order for only the wing with the protrusion of h+α' on the maximum outer diameter part 3B to have a machined surface, the dimension R' of the maximum outer diameter part with the protrusion after machining must be determined by considering the worst case. It must be set to R'≧R+r ₁ +p ₁ . The protrusion height h remaining after the above processing is nothing other than R'-R= _r1 + _p1 . (Generally, r ₁ = 0.3 mm and p ₁ = approximately 0.1 mm, so h is approximately 0.4 mm.) In any case, when implementing the present invention, (1) the turbine rough profile is 1 Maximum outer diameter of blade 3
B has a protrusion of h or more in the radial direction.

(2) When machining the maximum outer diameter part, set so that only the blade with protrusions undergoes machining.

is necessary.

In this way, in the large-diameter portion of the blades of the turbine rotor, only one of the ten blades has a processed metal surface, and the remaining nine blades have a cast surface, creating a contrast in brightness. still,
The rotor portion 6 (FIG. 2) located between each blade is originally a cast surface. As a result, a 0 degree phase with a width of one blade in the circumferential direction is obtained in the turbine rotor. That is, the protrusion 4 having a metal processed surface
A corresponds to the part painted with conventional paint or magic. The 0 degree phase due to this processed metal surface is determined by the photo sensor 10 (first
Since brightness and darkness can be easily distinguished from each other by (Fig.), it can be used as an accurate 0 degree phase when measuring unbalance.

Therefore, according to the present invention, as described above, the protrusion 4 provides a 0 degree phase at a step in the manufacturing process without requiring any additional work such as special painting.
A can be easily and reliably formed, but conversely, the protrusion 4A provided in this way may adversely affect the balance of the entire rotor by an amount corresponding to its weight. That is, the protrusion 4A itself may become a cause of imbalance. Therefore, according to the present invention, a second protrusion 4B is provided at a position opposite to the protrusion 4A in order to offset the imbalance caused by the protrusion 4A.
will be provided. The position of the second protrusion 4B differs depending on whether the number of blades is an even number or an odd number, so the following will explain each case separately.

1 When the number of blades is an even number (10 in the illustrated example)
In this case, since there is always a wing diametrically opposite to the wing provided with the first protrusion 4A, the second protrusion 4B may be provided on the large diameter portion 3B of that wing. What should be noted here is that the first protrusion 4A and the second protrusion 4B are arranged with their axial positions shifted and their respective axial lengths are ₁ and ₂ (Fig. 3), then ₁ = ₂ . That is to say. Preferably, if the axial length of the large diameter portion 3B of the blade 3 is ₀ , then
₁ = ₂ ≦ ₀ /2. Further, the second protrusion 4B is ground simultaneously when the first protrusion 4A is ground in exactly the same manner as the first protrusion 4A.
That is, at the stage of a rough profile, the turbine rotor has identical protrusions 4 whose positions in the axial direction are shifted on the large diameter part of only a pair of blades located at positions facing each other in the diametrical direction.
A, 4B (height=h+α') will be formed. The reason why the axial positions of the protrusions 4A and 4B are shifted is because the photo sensor 10 (FIG. 3) does not respond to the second protrusion 4B when detecting an unbalanced angle (phase). That is, the second protrusion 4B is also the same as the first protrusion 4.
Since the machining allowance α' is ground at the same time as A, it presents a metal machined surface, but since only the metal machined surface of the first protrusion 4A is necessary for the 0 degree phase, the second protrusion 4B Photo sensor 10
It is necessary to shift the optical axis position from the position of the optical axis. Therefore, the position of the second protrusion 4B is shifted from the photosensitive range of the photo sensor 10 in the rotor axial direction.

FIG. 5 is a pulse diagram showing the output of the photo sensor 10 (FIG. 3) when the unbalance of the turbine rotor according to the present invention is measured. In Figure 5, the position where the first protrusion 4A transitions from the metal processed surface (bright) to the cast surface (dark) is 0.
It is a degree phase. Apart from this, of course, it is also possible to set the position where the light changes from dark to bright as a phase of 0 degrees. A power pulse appears once per revolution of the turbine rotor. The pulse width D corresponds to the width of the metal processing surface (the plate thickness t at the maximum outer diameter portion of the blade).

2 When the number of blades is odd (11 in the illustrated example)
As shown in Figure 6, when the number of blades is a radial number, the second
As shown in the figure, when the number of blades is an even number, no blade exists on the diametrically opposite side of the blade provided with the first protrusion 4A. Therefore, in this case, conceptually, the second protrusion 4B may be divided and provided on a pair of wings located on the opposite side in the diametrical direction of the wing on which the first protrusion 4A is provided, sandwiching the diameter thereof. Become. Therefore, since the moments around the axis of the protrusions 4A and 4B (two pieces) need to be balanced, ₁ x h x t x ρ x r = 2 x ₂ x h x t x ρ x r cos θ... is established. However, r is the radius of the large diameter part of the blade, θ
(FIG. 6) shows the angle formed by each second projection 4B with respect to the diameter passing through the first projection 4A.

From the formula, ₁ = 2 ₂ cosθ... can be obtained.

That is, if the two second protrusions 4B are designed to have axial lengths and angular positions that satisfy the formula, the first
The unbalance caused by the protrusion 4A can be offset.

Generally, when the number N of turbine blades is an odd number, the large diameter portions of the two blades are located at index positions of (180-180/N) degrees and (180 + 180/N) degrees clockwise from the blade where the first protrusion is provided. The second protrusion may be provided by shifting the axial position from the first protrusion. At this time, if the axial lengths of the first and second protrusions are ₁ and ₂ , respectively, ₁ and ₂ are designed to have a relationship that satisfies ₁ = 2 ₂ ·cos (180°/N).

As described above, according to the present invention, it is possible to form metal processing surface protrusions for providing a 0 degree phase without adding any extra work at the manufacturing stage of the turbine rotor. All the shortcomings of technology will be eliminated.

In addition, according to the present invention, since the 0 degree phase is set at the large diameter portion of the blade, the 0 degree phase position is constant compared to when applying paint or magic, making it easier to carry the workpiece (turbine rotor) into the horizontal micro balancer. become certain.

Furthermore, according to the present invention, the unbalance caused by the protrusion provided to provide a 0 degree phase can be offset by another protrusion provided at a position opposite to the protrusion, which makes it possible to offset the imbalance caused by the protrusion provided in order to provide a 0 degree phase. There will be no imbalance caused by the implementation of the invention.

Note that there may be two or more second protrusions for offsetting the imbalance as long as they are provided symmetrically with respect to the axis of symmetry (diameter passing through the first protrusion). However, in that case, it goes without saying that the size of each second protrusion becomes smaller depending on the number of the second protrusions.

[Brief explanation of drawings]

FIG. 1 is a side view of a turbine rotor showing a conventional unbalance measuring method, FIG. 2 is a front view of a turbine rotor according to the present invention, FIG. 3 is a side view of FIG. 2, and FIG. 4 is a side view of a turbine rotor according to the present invention. 3 is a diagram explaining the manufacturing method of the turbine rotor shown in FIG. 3, FIG.
The figure which shows the example different from the figure. 3...Blade, 3A...Small diameter part, 3B...Large diameter part,
4A...first protrusion, 4B...second protrusion, 5...rotation shaft.

Claims (1)

[Scope of Claims] 1. A rotating body having a plurality of blades extending radially and concentrically around a central axis of rotation, the remaining blades being located at the maximum outer diameter of any one of the blades. A first protrusion in the radial direction having an outer surface different in brightness from the outer surface of the maximum outer diameter part of the blade is provided, and a center of rotation due to the protrusion is provided at the maximum outer diameter part of at least one wing that faces the wing provided with the first protrusion. A rotating body characterized in that a second protrusion for offsetting an imbalance around an axis is provided at a position shifted in the axial direction from the first protrusion. 2 A plurality of blades are provided that extend radially and concentrically around the central axis of rotation, and the maximum outer diameter of any one of these blades has a brightness that is different from the outer surface of the maximum outer diameter of the remaining blades. A first protrusion in the radial direction exhibiting a diameter is formed, and the first protrusion is formed at the maximum outer diameter portion of at least one wing that faces the first protrusion in the substantially diametrical direction.
A method for manufacturing a winged rotating body in which a second protrusion that offsets an imbalance around the center axis of rotation caused by the protrusion is shifted from the first protrusion in the axial direction, the rotary body being molded into a predetermined shape. At that time, the radial height of the first and second protrusions is made larger than the final predetermined dimensions, and then the outer surfaces of the first and second protrusions are processed to the predetermined dimensions. A method for manufacturing a rotating body with blades in which a difference in brightness is created by contrast between the machined surface and the cast surface of the maximum outer diameter portion of another blade.