JP3901569B2 - Dimension measurement device for workpiece - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dimension measuring equipment of the workpiece for measuring the maximum radius of the plurality of tip portion of the workpiece which has a rotationally symmetric shape about the axis.
[0002]
[Prior art]
In JP-A-11-125518, in order to measure the gap between the tip of a moving blade of a gas turbine engine and the inner peripheral surface of the casing, a detection head penetrating the casing is moved closer to and away from the tip of the moving blade. In addition, there is described what measures the gap from a position where the output of the detection head is turned on / off as the rotor blades rotate.
[0003]
Japanese Patent Laid-Open No. 2000-220408 discloses that a capacitance type probe is arranged to face the tip of the moving blade in order to measure the radius of the tip of the ceramic moving blade of the gas turbine engine. Is described in which the radius is measured based on a change in capacitance depending on the distance between the tip of the probe and the probe.
[0004]
Japanese Patent Laid-Open No. 11-83470 discloses that a sensor probe is moved from a tubular sensor case provided in a casing to measure the amount of extension of the moving blade tip in the radial direction by centrifugal force accompanying the operation of the steam turbine. And the amount of elongation is measured by bringing a thermocouple provided at the tip of the sensor probe into contact with the tip of the moving blade.
[0005]
[Problems to be solved by the invention]
By the way, what is described in the above-mentioned JP-A-11-125518 and JP-A-11-83470 needs to move the detection head and sensor probe at the time of measurement, so that the operation is troublesome and takes a lot of time for measurement. There was a problem that it took.
[0006]
In addition, since the capacitor described in Japanese Patent Laid-Open No. 2000-220408 uses a capacitance type probe, a metal coating must be applied to the rotor blade when measuring a ceramic rotor blade. Therefore, there was a problem that lacked versatility.
[0007]
Further, the one described in Japanese Patent Application Laid-Open No. 11-83470 has a possibility of damaging the moving blade because it is necessary to bring the thermocouple provided at the tip of the sensor probe into contact with the tip of the moving blade.
[0008]
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to make it possible to easily and accurately measure the radius of the tip of a work rotating about an axis.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, workpiece dimension measurement is performed to measure the maximum radius of a plurality of tip portions of a workpiece having a rotationally symmetric shape about an axis. In the apparatus, a base member, a center shaft that is erected on the base member and rotatably supports the workpiece around its axis, and a reference that is supported by the base member and can be opposed to the tip of the workpiece via a predetermined gap A shield, a laser transmitter and a laser receiver arranged so as to oppose each other at both ends in the tangential direction of the workpiece with the reference shield interposed therebetween, and any tip of the laser transmitter transmits laser light as the workpiece rotates Detecting means for detecting the position between the laser light receiving part and the laser light receiving part, and controlling the laser light sending from the laser light sending part based on the detection result of the detecting means, and the laser light receiving part And a control means for calculating a minimum value of the gap based on a light receiving state and calculating a maximum radius of the work from the smallest value among the minimum values of the gap at each tip. A dimension measuring apparatus is proposed.
[0010]
According to the above configuration, when the tip of the workpiece that is supported by the center shaft and rotates around the axis passes near the reference shield, the laser beam emitted from the laser transmitting unit passes through the gap and receives the laser light. Since the minimum value of the gap between the tip of the workpiece and the reference shield is calculated based on the light receiving state reaching the part, the minimum value of the gap can be calculated in a non-contact manner to prevent damage to the workpiece. Also, whenever the detection means detects that any tip is positioned between the laser transmitter and laser receiver as the workpiece rotates, it controls the laser beam transmission and calculates the minimum clearance. Therefore, the minimum value of the gap corresponding to the plurality of tip portions can be calculated automatically and without omission only by rotating the workpiece. Furthermore, since the maximum radius of the workpiece is calculated from the smallest value among the minimum values of the gaps corresponding to the respective tip portions, the maximum radius of the workpiece can be reliably calculated. Moreover, since laser light is used, measurement is not hindered by the material of the workpiece, and versatility is improved.
[0011]
According to the second aspect of the present invention, in addition to the configuration of the first aspect , the laser light transmission unit, the laser light reception unit, and the detection means are arranged at different angular positions with the axis as the center. Then, there is proposed a workpiece dimension measuring apparatus characterized in that, when the detecting means detects any tip, any other tip is located between the laser transmitting portion and the laser receiving portion.
[0012]
According to the above configuration, since the detecting means is arranged at a different angular position from the laser transmitting section and the laser receiving section, the degree of freedom in layout is increased so that the detecting means does not interfere with the laser transmitting section and the laser receiving section. While increasing the plurality of tip portions of the workpiece in a rotationally symmetric position, when the detection means detects any tip portion, any other tip portion is moved to the laser transmitter and laser receiver. It can be reliably positioned between them.
[0013]
According to the invention described in claim 3 , in addition to the configuration of claim 1 , the laser transmitting unit is provided over a predetermined period in which the tip of the workpiece is located between the laser transmitting unit and the laser receiving unit. A workpiece dimension measuring apparatus is proposed in which the laser beam is transmitted, and the control means calculates the minimum value of the gap based on the minimum amount of light received by the laser receiving unit during the period.
[0014]
According to the above configuration, the laser beam is transmitted over a predetermined period in which the tip of the workpiece is positioned between the laser transmitter and the laser receiver, and the workpiece tip is Since the minimum value of the gap with the reference shield is calculated, the minimum value of the gap can be accurately calculated even if the size of the gap varies with the rotation of the workpiece.
[0015]
According to the invention described in claim 4 , in addition to the structure of claim 1 , there is proposed a workpiece dimension measuring device characterized in that the tip of the workpiece is a blade body portion of a turbine wheel.
[0016]
According to the above configuration, since the maximum radius of the blade body portion of the turbine wheel can be calculated, the size of the clearance between the blade body portion and the shroud can be reliably grasped.
[0017]
The high-pressure turbine wheel 17 of the embodiment corresponds to the turbine wheel or the workpiece of the present invention, the blade main body portion 42a of the embodiment corresponds to the tip portion of the present invention, and the first and second first limit switches of the embodiment. 71 and 72 correspond to the detection means of the present invention, and the data processor 73 of the embodiment corresponds to the control means of the present invention.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings. 1 to 6 show an embodiment of the present invention, FIG. 1 is a diagram for explaining the overall structure of a turbofan engine, FIG. 2 is an overall side view of the measuring apparatus, and FIG. 3 is 3-3 in FIG. FIG. 4 is an enlarged view of a main part of FIG. 3, FIG. 5 is a diagram for explaining the operation of gap measurement, and FIG. 6 is a block diagram of a control system of the measuring apparatus.
[0019]
First, the overall structure of the turbofan engine will be described with reference to FIG. The turbofan engine includes an inner shaft 11 and an outer shaft 12 that is fitted to the outer periphery of the inner shaft 11 so as to be relatively rotatable. An axial flow type fan 13 is provided at the front end of the inner shaft 11, and an axial flow type first stage low pressure turbine wheel 14 and a second stage low pressure turbine wheel 15 are provided at the rear end. A centrifugal compressor wheel 16 is provided at the front end of the outer shaft 12 shorter than the inner shaft 11, and an axial flow type high-pressure turbine wheel 17 is provided at the rear end.
[0020]
A part of the air sucked from the front part of the engine and compressed by the fan 13 is discharged from the rear part of the engine through the bypass passage 18 arranged along the outer periphery of the engine, and the remainder of the air is the bypass passage. The air is guided to the compressor wheel 16 through a compressed air passage 19 disposed radially inward of the air pipe 18. The air further compressed by the compressor wheel 16 is supplied to an annular combustor 20 where it is mixed with the fuel injected from the fuel injection nozzle 21 and burned. The fuel gas generated in the combustor 20 includes a high-pressure turbine wheel 17 provided at the upstream end of the combustion gas passage 22, and first and second-stage low-pressure turbine wheels 14 and 15 provided in an intermediate portion of the combustion gas passage 22. It is discharged from the rear part of the engine through.
[0021]
Next, the structure of a measuring device that measures the maximum radius of the high-pressure turbine wheel 17 will be described with reference to FIGS.
[0022]
The high-pressure turbine wheel 17 includes a turbine disk 41 having a circular opening 41a in the center, and a plurality (18 in the embodiment) of turbine blades 42 arranged radially on the outer periphery of the turbine disk 41. Each turbine blade 42 includes a blade main body 42 a located on the radially outer side and a tree portion 42 b located on the radially inner side, and the tree portion 42 b engages with the outer peripheral portion of the turbine disk 41 in an uneven manner. It is firmly fixed to withstand a large centrifugal force. At both ends in the axial direction of the turbine disk 41, Kirbyk couplings (registered trademark) 41 b and 41 c are formed for coupling to intermediate portions of the outer shaft 12 divided in the axial direction.
[0023]
The measuring device includes a flat base member 51 and a center shaft 52 erected perpendicularly to the center of the base member 51. The lower end of the center shaft 52 is fitted into the support hole 51a of the base member 51, and a flange 52a provided at the lower portion of the center shaft 52 is fastened to the upper surface of the base member 51 with bolts 53 ... It is firmly fixed to the member 51. The center shaft 52 includes a tapered surface 52b that is tapered upward at an upper portion of the flange 52a, and a male screw portion 52c at the upper end.
[0024]
A hollow function shaft 54 is fitted to the outer periphery of the center shaft 52 with a slight gap, and a tapered surface 54a formed at the lower end of the function shaft 54 is engaged with the tapered surface 52b of the center shaft 52 without a gap. A hollow taper shaft 55 is slidably fitted to the upper portion of the center shaft 52, and a tapered surface 55a formed downward on the lower portion of the center shaft 52 has no gap between the tapered surface 54b formed on the upper end of the function shaft 54. Engageable. The taper surface 52b of the center shaft 52 and the taper surface 54a of the function shaft 54 are brought into contact with each other with an appropriate surface pressure, and the taper surface 54b of the function shaft 54 and the taper surface 55a of the taper shaft 55 are brought into contact with each other with an appropriate surface pressure. In order to make it possible, the nut 56 is screwed onto the male screw portion 52 c at the upper end of the center shaft 52.
[0025]
A thrust bearing 57 is disposed between the lower surface of the nut 56 and the upper surface of the taper shaft 55, and prevents the torque at the time of tightening the nut 56 from being transmitted to the taper shaft 55 through frictional force. Only the downward load is transmitted to the shaft 55. In this way, the axis of the function shaft 54 can be precisely matched with the axis L of the center shaft 52.
[0026]
A circular flange 54c is integrally formed at the lower end of the function shaft 54, and one carbic coupling 41b of the turbine disk 41 in which the opening 41a is fitted to the function shaft 54 is formed on the upper surface of the flange 54c. Engages with the big coupling 54d. Since the Carbic couplings 41b and 54d have a self-aligning function, the axis of the high-pressure turbine wheel 17 is precisely coincident with the axis of the function shaft 54 (that is, with respect to the axis L of the center shaft 52). To do.
[0027]
A circular positioning block 58 is slidably fitted to the outer periphery of the function shaft 54, and a Kirvic coupling 58 a formed on the lower surface thereof is engaged with the other Kirvic coupling 41 c of the turbine disk 41. A nut 59 is screwed into a male screw portion 54 e formed on the outer periphery of the function shaft 54, and a thrust bearing 60 is disposed between the lower surface of the nut 59 and the upper surface of the positioning block 58. The thrust bearing 60 prevents the torque at the time of tightening the nut 59 from being transmitted to the positioning block 58 via a frictional force, and transmits only a downward load to the positioning block 58. In this way, the axis of the high-pressure turbine wheel 17 can be more precisely matched with the axis L of the center shaft 52.
[0028]
Thus, the high-pressure turbine wheel 17 supported by the function shaft 54 and the positioning block 58 can freely rotate around the axis L of the center shaft 52 together with them. At this time, the tapered surface 52b of the center shaft 52 and the tapered surface 54a of the function shaft 54 slide relative to each other, and the tapered surface 54b of the function shaft 54 and the tapered surface 55a of the tapered shaft 55 slide relative to each other.
[0029]
The lower end of the support 61 is fitted into the support hole 51 b formed in the base member 51, and the flange 61 a provided at the lower part of the support 61 is fixed to the base member 51 with a plurality of bolts 62. A disc-shaped reference shield 63 is integrally provided at the upper end of the support 61, and the outer peripheral surface of the reference shield 63 is disposed at the tip of the blade body 42 a of each turbine blade 42 through a slight gap α. opposite. The gap α is not uniform for the 18 blade body portions 42a... When the radius of the blade body portion 42a centering on the axis L is large, the gap α is small, and when the radius of the blade body portion 42a is small, the gap α. Will grow.
[0030]
A pair of struts 64, 65 are fixed to the upper surface of the base member 51 with common bolts 66, 66, a laser light transmitting portion 67 is provided at the upper end of one strut 64, and a laser beam is received at the upper end of the other strut 65. A portion 68 is provided. The laser transmitter 67 and the laser receiver 68 are arranged so as to face each other on both sides in the tangential direction of the high-pressure turbine wheel 17 with the gap α between the reference shield 63 and the blade body 42 a interposed therebetween.
[0031]
A column 70 is erected on the upper surface of the base member 51 via bolts 69 and 69 at a position opposite to the reference shield 63 across the center shaft 52, and a first photoelectric switch is formed on the upper end of the column. A limit switch 71 and a second limit switch 72 are provided. As shown in FIG. 4, the first limit switch 71 and the second limit switch 72 are arranged at a position facing the tip of the blade body 42 a of the high-pressure turbine wheel 17, and the high-pressure turbine wheel 17 is shown in FIGS. 3 and 4. When rotating in the direction of arrow A, the first limit switch 71 detects the front end in the rotation direction of each blade body 42a, and the second limit switch 72 detects the rear end in the rotation direction of each blade body 42a.
[0032]
As shown in FIG. 6, the first limit switch 71 and the second limit switch 72 are connected to a laser beam transmitter 67, and the laser receiver 68 and the second limit switch 72 are connected to a data processor 73 such as a personal computer. Is done.
[0033]
Next, the operation of the embodiment of the present invention having the above configuration will be described.
[0034]
As shown in FIGS. 2 and 3, with the high-pressure turbine wheel 17 set in the measuring device, the high-pressure turbine wheel 17 is rotated in the direction of arrow A in FIGS. 3 and 4 manually or with an appropriate actuator. When the front end of the predetermined blade body 42a in the rotational direction is detected by the first limit switch 71, the laser transmitter 67 starts transmitting laser light toward the laser receiver 68 by the light transmission start signal. When the rear end of the blade body 42a in the rotational direction is detected by the second limit switch 72, the laser transmitter 67 stops the transmission of the laser light to the laser receiver 68 by the light transmission end signal. During the period in which the laser light is transmitted, the other predetermined blade main body part 42 a rotates between the laser light transmitting part 67 and the laser light receiving part 68 so as to pass near the reference shield 63.
[0035]
As is clear from FIG. 5, the width of the laser beam transmitted from the laser transmitting unit 67 is a predetermined width (for example, 5.0 mm), a part of which is blocked by the reference shield 63 and the other one. The part is blocked by the blade body 42a. Since the positional relationship between the laser transmitter 67 and the reference shield 63 is constant, the amount of light blocked by the reference shield 63 is constant, but the amount of light blocked by the rotating blade body 42a changes. Accordingly, the amount of light received by the laser receiving unit 68 is minimized when the radial tip of the blade body 42a is closest to the outer peripheral surface of the reference shield 63 and the gap α reaches the minimum value αmin.
[0036]
During the period when the laser beam is transmitted from the laser beam transmitter 67, the received light amount data received by the laser beam receiver 68 is input to the data processor 73, and the laser beam is transmitted by the light transmission end signal from the second limit switch 72. When the light transmitter 67 stops transmitting the laser light, the data processor 73 stores the data of the minimum amount of light received during the period in response to the trigger end signal from the second limit switch 72. In this way, when the high-pressure turbine wheel 17 rotates once and the minimum received light amount data corresponding to all 18 blade main body portions 42a is stored, the minimum of the 18 minimum received light amount data is stored. The blade body 42a from which the above data is obtained has the largest radius among the 18 blade body 42a. Since the predetermined distance R (see FIG. 5) from the axis L of the center shaft 52 to the surface of the reference shield 63 is known, the minimum value αmin of the gap α corresponding to the minimum data is subtracted from the predetermined distance R. The value (R−αmin) is the maximum radius of the high-pressure turbine wheel 17.
[0037]
As described above, only by rotating the high-pressure turbine wheel 17 once around the center shaft 52, each blade main body portion 42a of the high-pressure turbine wheel 17 is only in a period in which it exists between the laser light transmitting unit 67 and the laser light receiving unit 68. Since the laser light is transmitted and the minimum value αmin of the gap α is automatically calculated based on the minimum amount of light received during that period, the radius of each blade body 42a can be measured easily and precisely. And the radius of each blade main-body part 42a is memorize | stored, The maximum radius of the high pressure turbine wheel 17 is computable by selecting the largest thing from them.
[0038]
In addition, since the blade body 42a of the high-pressure turbine wheel 17 passes through the vicinity of the reference shield 63, the minimum value αmin of the gap α is calculated based on the minimum amount of laser light received during a predetermined period. Therefore, no error occurs in the minimum value αmin, and extremely precise measurement is possible. Further, since the measurement is performed in a non-contact manner using laser light, not only can the damage of the high-pressure turbine wheel 17 be prevented, but the versatility is enhanced because the measurement is not hindered by the material of the high-pressure turbine wheel 17.
[0039]
Further, since the first and second limit switches 71 and 72 are disposed at different angular positions from the laser light transmitting unit 67 and the laser light receiving unit 68, the first and second limit switches 71 and 72 are disposed in the laser light transmitting unit 67. Further, the degree of freedom in layout increases without interfering with the laser light receiving unit 68. Further, since the plurality of blade main body portions 42a... Of the high-pressure turbine wheel 17 are in rotationally symmetric positions, when the first and second limit switches 71 and 72 detect any one of the blade main body portions 42a, any one of the other. The blade main body portion 42 a can be reliably positioned between the laser light transmitting portion 67 and the laser light receiving portion 68.
[0040]
Since the maximum radius of the blade main body portions 42a of the high-pressure turbine wheel 17 can be calculated in this way, the size of the clearance between the blade main body portions 42a and the shroud can be reliably grasped.
[0041]
As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.
[0042]
For example, although non-contact type photoelectric switches are employed as the first and second limit switches 71 and 72 in the embodiment, contact-type mechanical limit switches can be employed instead.
[0043]
In the embodiment, the measurement of the radius of the blade main body portion 42a of the high-pressure turbine wheel 17 is exemplified. However, the present invention can be applied to the measurement of the radius of the tip portion of an arbitrary workpiece rotating around the axis.
[0044]
【The invention's effect】
According to the invention described in claim 1 as described above is supported by the Center shaft when the tip portion of the workpiece which rotates around the axis line passes near the reference shield, leaving the laser light transmitting unit Since the minimum value of the gap between the tip of the workpiece and the reference shield is calculated based on the light receiving state that the laser beam passes through the gap and reaches the laser receiving part, the minimum value of the gap is calculated without contact Workpiece damage can be prevented. Also, whenever the detection means detects that any tip is positioned between the laser transmitter and laser receiver as the workpiece rotates, it controls the laser beam transmission and calculates the minimum clearance. Therefore, the minimum value of the gap corresponding to the plurality of tip portions can be calculated automatically and without omission only by rotating the workpiece. Furthermore, since the maximum radius of the workpiece is calculated from the smallest value among the minimum values of the gaps corresponding to the respective tip portions, the maximum radius of the workpiece can be reliably calculated. Moreover, since laser light is used, measurement is not hindered by the material of the workpiece, and versatility is improved.
[0045]
According to the invention described in claim 2 , since the detecting means is disposed at an angular position different from the laser transmitting section and the laser receiving section, the detecting means does not interfere with the laser transmitting section and the laser receiving section. Thus, when the detection means detects any one of the tip parts, the other tip part is laser-exposed when the plurality of tip parts of the workpiece are in rotationally symmetric positions. It can be reliably positioned between the light transmitting unit and the laser light receiving unit.
[0046]
According to the invention described in claim 3 , the laser beam is transmitted over a predetermined period in which the tip of the workpiece is positioned between the laser beam transmitter and the laser beam receiver, and the minimum received light amount in that period is obtained. Since the minimum value of the gap between the tip of the workpiece and the reference shield is calculated based on this, even if the size of the gap varies with the rotation of the workpiece, the minimum value of the gap can be calculated accurately. .
[0047]
According to the invention described in claim 4 , since the maximum radius of the blade body portion of the turbine wheel can be calculated, it is possible to reliably grasp the size of the clearance between the blade body portion and the shroud. it can.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the overall structure of a turbofan engine. FIG. 2 is an overall side view of a measuring apparatus. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 5] Explanatory diagram of gap measurement [Fig. 6] Block diagram of control system of measuring device [Explanation of symbols]
17 Turbine wheel (high pressure turbine wheel, workpiece)
42a Blade body (tip)
51 Base member 52 Center shaft 63 Reference shield 67 Laser light transmitting section 68 Laser light receiving section 71 First limit switch (detecting means)
72 Second limit switch (detection means)
73 Data processor (control means)
L Axis R Predetermined distance α Clearance αmin Minimum clearance

Claims (4)

In the workpiece dimension measuring apparatus for measuring the maximum radius of the plurality of tip portions (42a) of the workpiece (17) having a rotationally symmetric shape about the axis (L),
A base member (51);
A center shaft (52) which is erected on the base member (51) and rotatably supports the workpiece (17) around its axis (L);
A reference shield (63) supported by the base member (51) and capable of facing the tip (42a) of the workpiece (17) via a predetermined gap (α);
A laser transmitter (67) and a laser receiver (68) disposed so as to oppose each other at both ends in the tangential direction of the workpiece (17) across the reference shield (63);
Detecting means (71, 72) for detecting that any of the tip portions (42a) is positioned between the laser light transmitting portion (67) and the laser light receiving portion (68) as the work (17) rotates;
Based on the detection result of the detection means (71, 72), the laser light transmission from the laser light transmission part (67) is controlled, and the gap (α) is determined based on the light reception state of the laser light reception part (68). Control means (73) for calculating the minimum value (αmin) and calculating the maximum radius of the workpiece (17) from the smallest value among the minimum values (αmin) of the gaps (α) of the respective tip portions (42a) When,
An apparatus for measuring a size of a workpiece, comprising: The laser transmitter (67), the laser receiver (68), and the detection means (71, 72) are arranged at different angular positions around the axis (L), and the detection means (71, 72). When any one of the tip portions (42a) is detected, any other tip portion (42a) is located between the laser light transmitting portion (67) and the laser light receiving portion (68). The workpiece dimension measuring apparatus according to claim 1 . The laser transmitter (67) transmits a laser beam over a predetermined period in which the tip (42a) of the work (17) is located between the laser transmitter (67) and the laser receiver (68). , the control means (73) and calculates the minimum value (.alpha.min) of the gap (alpha) based on the minimum light receiving quantity of the laser light receiving portion (68) is received in the period, according to claim 1 Dimension measuring device for workpieces. The workpiece dimension measuring device according to claim 1 , wherein the tip (42a) of the workpiece (17) is a blade body of a turbine wheel.

Images