JP2012172575A - Stator vane cascade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a manufacturing cost and prevent decrease of a natural frequency.SOLUTION: A stator vane cascade is formed by connecting a plurality of individualized units having stator vanes in the circumferential direction. Each individualized unit has a hook part and adjoining individualized units are connected to each other by engaging the hook parts with each other.

Description

  The present invention relates to a stationary blade row portion.

In order to improve the performance of the axial compressor, it is conceivable to reduce the blade thickness of the stationary blade and to provide a part that forms the flow path surface on the inner diameter side.
However, these structures cause a decrease in the natural frequency, and as such, there is a risk of resonating with the aerodynamic excitation force and resulting in damage to the parts.

  In order to solve such a problem, for example, as shown in Patent Document 1, the parts constituting the flow path surface of the inner and outer diameters are made into bands (bands) continuous in the circumferential direction, and the wings are assembled to improve the rigidity. A structure that avoids resonance (continuous blade structure) is widely used.

On the other hand, an individualized unit having an individualized inner band that constitutes a part of the inner band, an outer band that constitutes a part of the outer band, and a stationary blade sandwiched between the inner band and the outer band Patent Documents 2 and 3 disclose a technique for configuring a stationary blade row portion by connecting the two.
For example, the invention disclosed in Patent Document 2 has a structure for preventing thermal stress in a high-temperature part and restraining the positional relationship with adjacent components.
The invention disclosed in Patent Document 2 has a structure in which only a radial direction is constrained with respect to a relative position with an adjacent part, but it can slide without being constrained in a circumferential direction.

Further, the invention disclosed in Patent Document 3 is characterized in that it is integrated with adjacent components by twisting deformation of the shroud portion in the process of increasing the rotational speed of the rotating body. That is, the pressing force generated by the twist deformation restrains the positional relationship. Therefore, it is necessary to have a structure that is a rotating body and can tolerate necessary torsional deformation, and the restraining direction is limited to a direction parallel to the reaction force.
The invention disclosed in Patent Document 3 restricts only the direction parallel to the torsional reaction force with respect to the relative position with the adjacent parts, and is slidable and completely restricted in the vertical direction and the radial direction. Not.

US Patent Application Publication No. 2007/0102572 JP-A-1-310104 JP 2005-256786 A

  As a problem of the structure shown in Patent Document 1, because component parts are individually manufactured and joined, the amount of processing surplus given to each part is increased, and the manufacturing surplus discarded is also joined. The manufacturing cost may increase by the amount.

  In order to reduce the material surplus and the manufacturing cost, it is desirable that one blade and the corresponding inner and outer diameter flow path surfaces have an integrated structure (single blade structure), as shown in Patent Document 2 and Patent Document 3. It is desirable to use a singulation unit. However, in the structures of Patent Documents 2 and 3, it is difficult to prevent a decrease in the natural frequency.

  The present invention has been made in view of the above-described problems, and aims to reduce the manufacturing cost and prevent the natural frequency from decreasing.

  The present invention adopts the following configuration as means for solving the above-described problems.

  1st invention has the separated inner band which comprises a part of inner band, the outer band which comprises a part of outer band, and the stationary blade clamped by the said inner band and the said outer band A stationary blade row part formed by connecting a plurality of individualized units in the circumferential direction, each individualized unit having a hook part composed of an opening part and an engaging part, and engaging the hook parts with each other By doing so, a configuration in which adjacent individualized units are connected is adopted.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the hook portions are engaged with each other, a plurality of restraining surfaces that restrain the counterpart hook portion by contacting the counterpart hook portion are provided in the circumferential direction. The hook portion is configured such that the width increases toward the opening side.

According to the present invention, the individualized units are firmly fixed to each other, thereby improving the rigidity and preventing the natural frequency from being lowered.
In addition, according to the present invention, the shape of the singulated unit can be simplified to reduce the manufacturing cost.

It is a perspective view which shows a part of stationary blade row | line | column part in one Embodiment of this invention. It is a disassembled perspective view of the stationary blade row | line | column part in one Embodiment of this invention. It is a front view of the individualization unit of the stationary blade row | line | column part in one Embodiment of this invention.

  Hereinafter, an embodiment of a stationary blade row part according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

FIG. 1 is a perspective view showing a part of the stationary blade row portion of the present embodiment. FIG. 2 is an exploded perspective view of the stationary blade row portion of the present embodiment.
The stationary blade row portion 1 is mounted on a compressor of a jet engine, and a plurality of the stationary blade row portions 1 are arranged in the air flow direction alternately with the moving blade row portion in the compressor.
The stationary blade row portion 1 is formed in an annular shape around the central axis of the jet engine, and a plurality of stationary blades 4 are disposed between the inner band 2 and the outer band 3 as shown in FIG. It has a configuration.

The inner band 2 is an annular member arranged closer to the center axis of the jet engine than the outer band 3.
The outer band 3 is an annular member that is disposed at a position farther away from the central axis of the jet engine than the inner band 2 in the radial direction.
A region sandwiched between the inner band 2 and the outer band 3 is an air flow path, and a plurality of stationary blades 4 are arranged at equal intervals in the region.

  The stationary blade 4 performs air rectification between the inner band 2 and the outer band 3, and is arranged with the front edge facing the front of the jet engine and the rear edge facing the rear of the jet engine.

  FIG. 2 is an exploded perspective view of the stationary blade row 1. As shown in this figure, the stationary blade row portion 1 of the present embodiment is separated into pieces for each stationary blade 4, and this separated unit (hereinafter referred to as a separated unit 10) is annular. It is comprised by connecting to two or more.

The singulation unit 10 forms the stationary blade row portion 1 by being continuous, and constitutes a part of the stationary blade row portion 1. More specifically, the stationary blade row portion 1 is divided for each stationary blade 4, and one of the divided bodies is used as an individual unit 10.
As shown in FIG. 2, the singulation unit 10 includes a stationary blade 4, an individualized inner band 11 that constitutes a part of the inner band 2, and an individualization that constitutes a part of the outer band 3. An outer band 12 is provided.

FIG. 3 is a front view of the singulation unit 10 as viewed from the central axis direction of the jet engine.
As shown in this figure, each singulation unit 10 in the stationary blade row portion 1 of the present embodiment has four hook portions 13 that engage with the adjacent singulation units 10.

The hook part 13 positions the adjacent individualized units 10 by being locked with the hook part 13 of the adjacent individualized unit 10, and includes the individualized inner band 11 and the individualized outer band. 12 at the end.
More specifically, a hook portion 13 is provided at each of both end portions in contact with the adjacent individualized inner band 11, and the hook portion 13 provided at one end portion projects upward. A hook portion 13 provided at the other end portion projects downward, and the hook portion includes an engaging portion and an opening portion. These hook portions 13 are constrained surfaces 13a that restrain the mating hook portion 13 by abutting against the mating hook portion 13 when the hook portions 13 are engaged with each other by inserting the engaging portion into the opening. , 13b in the circumferential direction, and one restraint surface 13a is inclined with respect to the other restraint surface 13b. At this time, the hook part should just be the shape where the width | variety becomes large as it goes to the opening side.
By engaging the hook portions 13 with each other, the individualized units 10 adjacent to each other in the circumferential direction can be firmly fixed. For this reason, the rigidity of the stationary blade row portion 1 can be improved, and the reduction of the natural frequency can be prevented.

  Further, the individualized unit 10 having such a hook portion 13 can be easily manufactured in a net shape by using precision forging, powder injection molding or the like as a manufacturing method, and does not require a joining cost and is discarded. Remaining material surplus is also reduced.

In addition, since the hook part 13 performs the function of improving the rigidity of the stationary blade row part 1, it is necessary to tighten the fitting more than a certain level.
Furthermore, this fitting must maintain a certain degree of fitting even when variations due to manufacturing errors are taken into account.
In order to realize this, it is preferable that the constraining surfaces 13a and 13b of the opposing hook portions are not parallel but are constituted by two surfaces inclined with respect to one side as described above.
By providing the inclination, the restraint surface 13a can restrain in two directions, and the number of restraint surfaces can be reduced accordingly. Since the constraining surface needs to be manufactured with high accuracy, reducing the constraining surface contributes to an improvement in manufacturing cost and manufacturing yield.

In addition, when two parallel surfaces are used as the above-mentioned constraining surfaces, when the fit becomes tighter than the design intent due to manufacturing errors, there is no escape from interference due to the fit, and assembly becomes difficult. Cannot fit.
On the other hand, when the constraining surface 13a is inclined with respect to the constraining surface 13b as in the present embodiment, even when the fitting becomes tighter than the design intention due to manufacturing errors, the hook portion 13 is in a direction to avoid interference. By slightly moving, interference is mitigated and assemblability can be secured. Thereby, it is possible to take a tight fit above a certain level.
At this time, elastic strain is accumulated at the base of the hook portion 13 with a slight movement of the hook portion 13. Due to this elastic strain, a repulsive force that causes the hook portion 13 to return to the original state is generated. Therefore, the constraining surfaces 13a and 13b are not peeled off, and a constant constraining force is maintained, thereby improving rigidity.

In the stationary blade row portion 1 having such a book portion 13, the hook wall surfaces (restraining surfaces 13 a and 13 b) have an angle with respect to the radial direction, so that the radial displacement and the circumferential displacement are performed in two directions. Can be controlled.
Further, regarding the radial direction, the hook portions 13 of the individualized outer band 12 and the individualized inner band 11 are made symmetrical with respect to the radial direction, so that they are stretched against each other in the radial direction and the displacement is restricted.
Further, with respect to the circumferential direction, each hook portion is fitted in the circumferential direction, and displacement is restrained. At this time, with respect to the axial direction, after assembling each individual unit, the outer band portion 3 is fixed by sandwiching the outer band portion 3 from the front and rear by a casing (not shown), and the axial displacement is restrained.
And by making the hook part 13 of the circumferential direction right end and left end of the individualization unit 10 into a point-symmetrical shape, it becomes a shape with periodicity in the circumferential direction, and the individualization unit 10 can be shared.

Further, the present embodiment is different from the invention disclosed in Japanese Patent Laid-Open No. 1-310104 in that it has a structure for positively constraining the positional relationship with adjacent parts for the purpose of improving the natural frequency.
Specifically, the hook portion 13 of the present embodiment has a structure in which the positional relationship is restricted in both the circumferential direction and the radial direction.

  Further, the present embodiment does not require torsional deformation in the process of increasing the rotational speed, and can be used even if it is not a rotating body. In addition, it is characterized in that it can be restrained in a plurality of directions by adjusting the shape of the hook portion.

As can be seen from the data relating to the vibration frequency shown in Table 1 as a result of structural analysis, the present embodiment is disclosed in Japanese Patent Laid-Open No. 1-310104 and Japanese Patent Laid-Open No. 2005-256786. Compared to the invention, the effects of disappearance of the vibration mode and a significant improvement in the frequency can be obtained.
By adjusting the location of the hook part, it is possible to effectively cope with modes that need to be avoided, such as bending mode and torsion mode.

As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
For example, the hook portion only needs to increase in width toward the opening side, and there may be a plurality of constraining surfaces or a curved surface.

  1 …… Static blade row portion, 2 …… Inner band, 3 …… Outer band, 4 …… Static blade, 10 …… Divided unit, 11 …… Divided inner band, 12 …… Divided outer Band, 13 ... Hook, 13a, 13b ... Restraint surface

Claims (2)

An individualized unit including an individualized inner band that constitutes a part of the inner band, an outer band that constitutes a part of the outer band, and a stationary blade that is sandwiched between the inner band and the outer band. A stationary blade row portion formed by connecting a plurality of the directions,
Each vane unit has a hook part composed of an opening and an engaging part, and the individual vane unit is connected by engaging the hook parts with each other. .   When the hook portions are engaged with each other, the engaging portions of the hook portions have a plurality of restraining surfaces in the circumferential direction that come into contact with the mating hook portions to restrain the mating hook portions, and the hook portions face the opening side. The stationary blade row portion according to claim 1, wherein the width of the stationary blade row portion increases.

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