Measuring tool and measuring method for measuring chord length of multi-union blade and application

Abstract

The invention discloses a measuring tool for measuring chord length of a multi-union blade, a measuring method and application, and belongs to the technical field of measurement. The measuring tool for measuring the chord length of the multi-union blade comprises a main scale and a vernier scale, the vernier scale is provided with a vernier part, and the vernier part can freely slide relative to the main scale in the length direction of the main scale; the vernier part is provided with a reading window capable of displaying the displacement change of the vernier part relative to the main ruler; the vernier part is fixedly connected with a depth rod, and the depth rod can freely slide relative to the main ruler in the length direction of the main ruler and protrudes out of the main ruler; the tail end of the depth rod is provided with a first measuring claw, and one side of the first measuring claw close to the main ruler is parallel to the end face of the depth rod protruding out of the main ruler. By arranging the first measuring claw at the tail end of the depth rod and utilizing the characteristic that the depth rod is narrower than the main ruler, compared with the scheme of using an outer measuring claw in the prior art, the depth rod is easier to go deep into gaps between multi-connected blades to measure the chord length of the blades, and the problem that the chord length of the blades is difficult to measure due to obstruction of adjacent blades in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of measurement technology, and in particular to a measuring tool for measuring the chord length of multiple blades, a measuring method and an application thereof. Background Art

[0002] Chord length is a must-check item in blade inspection (chord length of each radial section of the blade airfoil), which has a significant impact on the blade profile, guide vane throat area, etc. At present, the detection method for the chord length of single-joint blades at home and abroad is pallet or three-coordinate measuring instrument, and the chord length of multi-joint blades can only be measured by three-coordinate measuring instrument. The universality of pallet tooling is poor; three-coordinate is less efficient when detecting single-size or multiple types of blades.

[0003] Prior art CN113280712A discloses a precise blade chord length measurement tool and a method and process for using it. By modifying the vernier caliper outer diameter measuring jaws, it becomes a chord length detection tool. However, different modified calipers are required to measure the chord lengths of blades in different combinations. Due to the width limitation of the vernier caliper outer diameter measuring jaw area, the chord length of the middle blade of a triple or more combination cannot be measured (the gap between the triple or more blades is small, and the fluid channel between the blades is a curved surface, when the outer diameter measuring jaw area is used for measurement). Before detection, the vernier caliper cannot be reset to zero due to the presence of the positioning block, resulting in the need to indirectly obtain the result based on the difference before and after. Therefore, making an intuitive, efficient and universal chord length measuring tool has become an important demand in the blade measurement industry.

[0004] In addition, the mechanical wear of turbine blades needs to be evaluated after a period of use, and chord length is one of the important indicators. The difficulty of blade inspection is further increased due to the size limitations of the environment after installation. The existing technology for measuring used turbine blades often requires the turbine to be disassembled and completely removed from use, which has the defects of long cycle and low efficiency. Summary of the invention

[0005] In view of the above analysis and in response to the deficiencies in the prior art, the present invention aims to provide a measuring tool, a measuring method and an application for measuring the chord length of multi-blades, so as to solve at least one of the problems in the prior art of difficulty in measuring the chord length of multi-blades with small gaps and long inspection cycle and low efficiency of turbine blades after use.

[0006] The purpose of the present invention is mainly achieved through the following technical solutions:

[0007] The present invention discloses a measuring tool for measuring the chord length of a multi-joint blade, comprising:

[0008] Main scale and vernier scale;

[0009] The vernier scale is provided with a vernier portion, and the vernier portion can slide freely relative to the main scale in the length direction of the main scale;

[0010] The vernier part is provided with a reading window capable of displaying the displacement change of the vernier part relative to the main scale;

[0011] The cursor part is fixedly connected with a depth rod, and the depth rod can slide freely relative to the main scale in the length direction of the main scale and protrude from the main scale;

[0012] A first measuring claw is disposed at the end of the depth rod, and a side of the first measuring claw close to the main scale is parallel to an end surface of the depth rod protruding from the main scale.

[0013] Preferably, the vernier part is arranged around the main scale, and the vernier part and the main scale are connected by a pulley.

[0014] Preferably, the pulleys are symmetrically arranged on both sides of the main scale.

[0015] Preferably, a slide groove is provided inside the main ruler, and the depth rod can slide in the slide groove relative to the main ruler.

[0016] Preferably, a main zeroing claw is provided at the other end of the main scale relative to the protruding end of the depth rod in the length direction of the main scale, and a secondary zeroing claw is provided at the same end of the vernier scale;

[0017] The end surfaces of the main zero-marking claw and the auxiliary zero-marking claw facing each other are parallel and can abut against each other when the reading window shows the minimum value.

[0018] Preferably, a second measuring claw is provided at one end of the depth rod protruding in the length direction of the main scale, and the second measuring claw is flush with the end surface of the depth rod protruding from the main scale.

[0019] Preferably, the first measuring jaw and the second measuring jaw are foldable structures.

[0020] Preferably, the cursor portion is further provided with a fixing knob.

[0021] A method for measuring the chord length of a multi-jointed blade uses the multi-jointed blade chord length measuring tool.

[0022] An application of a blade chord length measuring tool, using the above-mentioned multi-joint blade chord length measuring tool to measure the chord length of the multi-joint blades.

[0023] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0024] (1) The present invention provides a first measuring claw at the end of the depth rod, and utilizes the characteristic that the depth rod is thinner than the main ruler. Compared with the prior art solution using an external measuring claw, the present invention is more likely to penetrate into the gap between multiple blades to measure the blade chord length, thereby avoiding the problem in the prior art that the blade chord length is difficult to measure due to obstruction by adjacent blades.

[0025] (2) The present invention provides a measuring zero point for the measuring tool by setting a main zeroing claw 1 at the end of the main scale and setting a secondary zeroing claw at the vernier part, and adjusting the parameters of the digital display vernier scale or the starting zero points of the first scale area and the second scale area of ​​the mechanical vernier scale, so that when the main zeroing claw and the secondary zeroing claw are in contact, the reading of the vernier scale is zero, and at the same time, it is ensured that the first measuring claw and the main scale are in contact at this position, thereby achieving the consistency of the initial zero point of the measured value and the actual value, thereby ensuring the accuracy of subsequent measurement data;

[0026] (3) The present invention provides a second measuring claw flush with the end surface at the protruding end of the depth rod of the main ruler, so as to achieve penetration into the area to be measured from different fluid directions, thereby achieving measurement of the chord length of the blade from different directions, thereby avoiding the problem of completely disassembling the turbine installation to measure the chord length of the blade in the prior art, reducing the interference of the installation position or size on the measurement, and improving the application range of the measuring tool, thereby overcoming the problem that the blade detection in the prior art is restricted by the environment, has a long detection cycle and low efficiency;

[0027] (4) The present invention sets the main ruler at the first measuring claw and the second measuring claw as a foldable structure, which can flexibly adjust the length of the first measuring claw and the second measuring claw. It can not only achieve the penetration of the measured area from different fluid directions, but also avoid the measurement claw being too long to enter a small space for measurement. It can meet the measurement needs of different spaces at the same time, further improve the application range of the measuring tool, and overcome the problems in the prior art that blade detection is restricted by the environment, has a long detection cycle, and is low in efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0029] Figure 1 A three-dimensional view of a typical multi-blade turbine.

[0030] Figure 2 Schematic diagram of a multi-blade chord length measuring tool according to Embodiment 1 and Embodiment 3 of the present invention.

[0031] Figure 3 Schematic diagram of a multi-blade chord length measuring tool according to embodiment 2 of the present invention.

[0032] Figure 4 Schematic diagram of a multi-blade chord length measuring tool according to embodiment 4 of the present invention.

[0033] Figure 5 Schematic diagram of a multi-blade chord length measuring tool according to embodiment 5 of the present invention.

[0034] Reference numerals:

[0035] Blade 01; Rotating shaft 02; Fluid channel 03;

[0036] A first end surface 011; a second end surface 012;

[0037] Main ruler 1; main mark zero claw 102; second measuring claw 103; second hinge structure 1031;

[0038] Vernier scale 2; vernier portion 201; auxiliary zeroing claw 202; reading window 203; fixed knob 204; depth rod 205; first measuring claw 206; first hinge structure 2061. DETAILED DESCRIPTION

[0039] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] The present invention discloses a turbine with multiple blades, such as Figure 1 The figure includes: a blade 01 and a rotating shaft 02; a plurality of blades 01 are provided, the root of the blade 01 is fixed to the side of the rotating shaft 02, and the tip of the blade 01 is used as a free end;

[0041] The gaps between adjacent blades 01 and the rotating shaft 02 form a fluid channel 03;

[0042] A plurality of blades 01, a rotating shaft 02 and a fluid channel 03 form a turbine structure;

[0043] The blade 01 is defined as a first end surface 011 at the inlet end of the fluid channel 03 and a second end surface 012 at the outlet end of the fluid channel 03;

[0044] The first end surface 011 is wider than the second end surface 012 , and the radial cross-section of the blade is in the shape of a teardrop.

[0045] It should be noted that the multi-blade structure has a small spacing between the multiple blades, and is easily obstructed by adjacent blades when measuring the blade chord length, thus hindering the chord length measurement; although the water drop structure helps to reduce fluid resistance, the width of the water drop structure is different at the water inlet and outlet directions, which puts higher requirements on the measurement direction of the measuring tool and the matching of the measuring tool with the two end faces of the water drop structure.

[0046] In one aspect, the present invention discloses a measuring tool for measuring the chord length of multiple blades, such as Figure 2 As shown, including:

[0047] Main scale 1 and vernier scale 2;

[0048] The vernier scale 2 is provided with a vernier portion 201, and the vernier portion 201 can slide freely relative to the main scale 1 in the length direction of the main scale 1;

[0049] The vernier part 201 is provided with a reading window 203 which can display the displacement change of the vernier part 201 relative to the main scale 1;

[0050] The cursor part 201 is fixedly connected to a depth rod 205, which can freely slide relative to the main scale 1 in the length direction of the main scale 1 and protrude from the main scale. A first measuring claw 206 is provided at the end of the depth rod 205. The first measuring claw 206 is parallel to the end face of the depth rod 205 protruding from the main scale 1 on the side close to the main scale 1.

[0051] During implementation, the reading of the reading window 203 is recorded when the first measuring claw 206 abuts against the end surface of the main scale 1, and the cursor part 201 is moved so that the depth rod 205 protrudes from the main scale 1 while adjusting the protruding distance of the main scale 1; the depth rod 205 is pushed deeper into the fluid channel 03, and the angle of the depth rod 205 is adjusted so that the blade to be measured is in the area between the first measuring claw 206 and the main scale 1; the cursor part 201 is continuously adjusted so that the first end surface 011 and the second end surface 012 of the blade 01 abut against the first measuring claw 206 and the main scale 1 one by one, that is, the first end surface 011 abuts against one of the first measuring claw 206 and the main scale 1, and the second end surface 012 abuts against the other of the first measuring claw 206 and the main scale 1; thereby the blade chord length is measured, and the value is displayed through the reading window 203.

[0052] Compared with the prior art, the present invention sets a first measuring claw at the end of the depth rod and utilizes the characteristic that the depth rod is thinner than the main ruler. It is easier to penetrate into the gap between multiple blades to measure the blade chord length than the prior art solution using an external measuring claw, thus avoiding the problem in the prior art that the blade chord length is difficult to measure due to obstruction by adjacent blades.

[0053] Specifically, the cursor portion 201 is disposed around the main scale 1, and the two may be connected via a pulley (not shown).

[0054] Preferably, the pulleys are symmetrically arranged on both sides of the main scale 1, so that when the cursor portion 201 slides relative to the main scale 1, the displacement in the non-sliding direction can be reduced, thereby improving stability and measurement accuracy.

[0055] Specifically, a slide groove (not shown, the same as the related design of the vernier caliper in the prior art) is provided inside the main scale 1, and the depth rod 205 slides relative to the main scale 1 in the slide groove.

[0056] A feasible embodiment is as follows: Figure 2 As shown, the vernier scale 2 is a digital display vernier scale, and the reading window 203 can directly display the displacement of the vernier part 201 relative to the main scale 1.

[0057] A feasible embodiment is as follows: Figure 3As shown, the vernier ruler 2 is a mechanical vernier ruler, the main ruler 1 is provided with a first scale area, the surface of the vernier part 201 is provided with a second scale area, the actual length δ1 of the basic unit of the first scale area is generally set to 1mm, the actual length of the basic unit of the second scale area is δ2, the number of basic units in the second scale area is n, and the maximum scale of the second scale area is K. In order to make the mechanical vernier ruler obtain the target accuracy δ, it satisfies:

[0058] δ = δ1-δ2;

[0059] δ2=K / n; wherein K and n can be generally selected and determined according to the design of the vernier caliper in the prior art, for example, when δ=0.02, n=50; when δ=0.05, n=20.

[0060] A preferred embodiment, as Figure 4 As shown, a main zeroing claw 102 is provided at the other end of the main scale 1 protruding relative to the depth rod 205 in the length direction, and a secondary zeroing claw 202 is provided at the same end of the vernier scale 2;

[0061] The end surfaces of the main zero-marking claw 102 and the auxiliary zero-marking claw 202 facing each other are parallel and can abut against each other when the reading window 203 shows the minimum value.

[0062] During implementation, when the cursor part 201 is displaced toward the end of the main scale 1 where the main zero claw 102 is provided, the main zero claw 102 and the secondary zero claw 202 move toward each other, and the distance between the main zero claw 102 and the secondary zero claw 202 decreases synchronously with the length of the depth rod 205 protruding from the main scale 1, until the distance between the main zero claw 102 and the secondary zero claw 202 is 0; similarly, when the cursor part 201 is displaced away from the end of the main scale 1 where the main zero claw 102 is provided, the main zero claw 102 and the secondary zero claw 202 move back to back, and the distance between the main zero claw 102 and the secondary zero claw 202 increases synchronously with the length of the depth rod 205 protruding from the main scale 1.

[0063] It should be noted that the main zeroing claw 102 and the auxiliary zeroing claw 202 are set to provide a measurement zero point for the measuring tool, and the parameters of the digital vernier scale or the starting zero points of the first scale area and the second scale area of ​​the mechanical vernier scale are adjusted so that when the main zeroing claw 102 and the auxiliary zeroing claw 202 are in contact, the reading of the vernier scale is zero, and at the same time, it is ensured that the first measuring claw 206 and the main scale 1 are in contact at this position, thereby achieving consistency between the initial zero point of the measured value and the actual value, thereby ensuring the accuracy of subsequent measurement data.

[0064] It is understandable that, for a digital display vernier scale, since it does not have a scale area of ​​its own, it is particularly important to ensure that when 102 and the auxiliary zero claw 202 are in contact, the first measuring claw 206 and the main scale 1 are in contact.

[0065] Preferably, if Figure 2-Figure 5As shown, the vernier part 201 is also provided with a fixed knob 204, which is used to ensure that the positions of the vernier part 201 and the main scale 1 are fixed when measuring readings, thereby reducing errors caused by instability.

[0066] Preferably, if Figure 4 As shown, the main ruler 1 is provided with a second measuring claw 103 at one end of the depth rod 205 protruding therefrom, and the second measuring claw 103 is flush with the end surface of the depth rod 205 protruding therefrom.

[0067] During implementation, the second measuring claw 103 is flush with the end surface where it is located, so that the distance between the second measuring claw 103 and the first measuring claw 206 is the same as the distance between the first measuring claw 206 and the main scale 1. When the blade to be measured is in contact with the second measuring claw 103 and the first measuring claw 206 during measurement, the distance between the two is the chord length of the blade to be measured.

[0068] Understandably, relatively Figure 2 As shown, the blade is measured along the curved surface on one side of the depth rod 205, as shown in FIG. Figure 4 In the solution shown, due to the addition of the second measuring claw 103, the blade can be additionally measured in the direction in which the first end face 011 abuts against the second measuring claw 103. This is because: the abutting position of the first end face 011 is farther from the end face of the main scale 1, and a larger abutting fixing area needs to be reserved; Figure 4 In the illustrated solution, the second measuring claw 103 is added to cooperate with the first measuring claw 206 , which can provide more fixing areas for fixing and measuring the blade, thereby enabling the first end surface 011 to abut against the second measuring claw 103 for measurement.

[0069] Compared with the prior art, the present invention provides a second measuring claw 103 flush with the end surface at the protruding end of the depth rod 205 of the main ruler 1, thereby achieving penetration into the area to be measured from different fluid directions, and further measuring the chord length of the blade from different directions, thereby avoiding the problem of completely disassembling the turbine installation in order to measure the chord length of the blade in the prior art, reducing the interference of the installation position or size on the measurement, improving the application scope of the measuring tool, and overcoming the problems in the prior art that blade detection is restricted by the environment, has a long detection cycle, and is inefficient.

[0070] Preferably, the first measuring claw 206 and the second measuring claw 103 are foldable structures.

[0071] Specifically, Figure 5 As shown, the second measuring claw 103 is provided with a second hinge structure 1031, which divides the second measuring claw 103 into two foldable parts; the first measuring claw 206 is provided with a first hinge structure 2061, which divides the first measuring claw 206 into two foldable parts.

[0072] Preferably, the rotation range of the second hinge structure 1031 and the first hinge structure 2061 is 0° to 180°.

[0073] Preferably, the second measuring claw 103 is provided with a fixing bolt (not shown) to ensure the fixing rigidity of the two parts of the second measuring claw 103 when the second hinge structure 1031 rotates 180°, that is, when the two parts of the second measuring claw 103 can rotate relative to each other to be horizontally coplanar.

[0074] Preferably, the first measuring claw 206 is provided with a fixing bolt (not shown) to ensure the fixing rigidity of the two parts of the first measuring claw 206 when the two parts are rotated 180°, that is, the first measuring claw 206 can be relatively rotated to be horizontally coplanar.

[0075] When implementing, Figure 5 As shown, according to the requirement of the first end face 011 and the second end face 012 of the blade for fixing space when measuring the chord length of the blade, the first measuring claw 206 and the second measuring claw 103 are selected to be fully unfolded or folded.

[0076] Compared with the prior art, the present invention sets the first measuring claw 206 and the second measuring claw 103 as a foldable structure in the main ruler 1, so as to flexibly adjust the length of the first measuring claw 206 and the second measuring claw 103. It can not only realize the penetration of the measured area from different fluid directions, but also avoid the measurement claw being too long to enter a small space for measurement. It can meet the measurement needs of different spaces at the same time, further improve the application scope of the measuring tool, and overcome the problems in the prior art that blade detection is restricted by the environment, has a long detection cycle and low efficiency.

[0077] In another aspect, the present invention discloses a method for measuring the chord length of a multi-jointed blade, using the above-mentioned measuring tool, comprising the following steps:

[0078] S1. Reference zero adjustment:

[0079] The main zero-marking claw 102 and the auxiliary zero-marking claw 202 are brought into contact;

[0080] Check the reading window indication and the contact status between the first measuring claw 206 and the main ruler 1;

[0081] If the reading window shows zero and the first measuring claw 206 and the main scale 1 are in contact at the same time, the zero adjustment is completed and the device meets the requirements;

[0082] Otherwise, the processing accuracy of the device does not meet the requirements and cannot be used as a qualified measuring tool;

[0083] S2. Measurement angle adjustment:

[0084] Adjust the protruding length of the depth rod of the zero-adjusted measuring tool to a value greater than the predicted value of the chord length of the blade to be measured;

[0085] Rotate the depth rod to a suitable angle to move the first measuring claw 206 deeper into the fluid channel from the fluid channel inlet or outlet;

[0086] Rotate the depth rod again so that the first end surface and the second end surface of the blade are located between the first measuring claw 206 and the main scale 1, or in the area to be measured between the first measuring claw 206 and the second measuring claw 103;

[0087] The first end surface and the second end surface of the blade are abutted against the first measuring claw 206 and the main scale 1 in a one-to-one correspondence, or the first end surface and the second end surface of the blade are abutted against the first measuring claw 206 and the second measuring claw 103 in a one-to-one correspondence;

[0088] S3. Data measurement:

[0089] Fixed knob, based on the reading window reading.

[0090] In a third aspect, the present invention further discloses an application of a blade chord length measuring tool, which is used to measure the chord length of multiple blades.

[0091] In order to better illustrate the present invention, the following embodiments are further provided:

[0092] Example 1

[0093] This embodiment discloses a measuring tool for measuring the chord length of multiple blades, such as Figure 2 As shown, the main scale 1 and the vernier scale 2; the vernier scale 2 is provided with a vernier portion 201, and the vernier portion 201 can slide freely relative to the main scale 1 in the length direction of the main scale 1;

[0094] The vernier part 201 is provided with a reading window 203 which can display the displacement change of the vernier part 201 relative to the main scale 1;

[0095] The cursor part 201 is fixedly connected to a depth rod 205, which can slide freely relative to the main scale 1 and protrude from one end face of the main scale 1 in the length direction. A first measuring claw 206 is provided at the end of the depth rod 205, and the first measuring claw 206 is parallel to the end face of the depth rod 205 protruding from the main scale 1 on the side close to the main scale 1.

[0096] The reading of the reading window 203 is recorded when the first measuring claw 206 abuts against the end surface of the main scale 1, and the cursor part 201 is moved so that the depth rod 205 protrudes from the main scale 1 while adjusting the protruding distance of the main scale 1; the depth rod 205 is pushed deeper into the fluid channel 03, and the angle of the depth rod 205 is adjusted so that the blade to be measured is in the area between the first measuring claw 206 and the main scale 1; the cursor part 201 is continued to be adjusted so that the first end surface 011 and the second end surface 012 of the blade 01 abut against the first measuring claw 206 and the main scale 1; thereby the blade chord length is measured, and the value is displayed through the reading window 203.

[0097] The cursor part 201 is arranged around the main scale 1, and the two can be connected by a pulley (not shown).

[0098] The pulleys are symmetrically arranged on both sides of the main scale 1. When the cursor part 201 slides relative to the main scale 1, the displacement in the non-sliding direction can be reduced, thereby improving stability and accuracy.

[0099] A slide groove is provided inside the main ruler 1, and the depth rod 205 slides relative to the main ruler 1 in the slide groove.

[0100] like Figure 2 As shown, the vernier scale 2 is a digital display vernier scale, and the reading window 203 can directly display the displacement of the vernier part 201 relative to the main scale 1.

[0101] The vernier part 201 is also provided with a fixed knob 204, which is used to ensure that the positions of the vernier part 201 and the main scale 1 are fixed when measuring readings, thereby reducing errors caused by instability.

[0102] On the other hand, this embodiment discloses a method for measuring the chord length of a multi-jointed blade, using the above-mentioned measuring tool, comprising the following steps:

[0103] S1. Reference zero adjustment:

[0104] Check the reading window indication and the contact status between the first measuring claw 206 and the main ruler 1;

[0105] If the reading window shows zero and the first measuring claw 206 and the main scale 1 are in contact at the same time, the zero adjustment is completed and the device meets the requirements;

[0106] Otherwise, the processing accuracy of the device does not meet the requirements and cannot be used as a qualified measuring tool;

[0107] S2. Measurement angle adjustment:

[0108] Adjust the protruding length of the depth rod of the zero-adjusted measuring tool to a value greater than the predicted value of the chord length of the blade to be measured;

[0109] Rotate the depth rod to a suitable angle to move the first measuring claw 206 deeper into the fluid channel from the fluid channel inlet or outlet;

[0110] Rotate the depth rod again so that the first end surface and the second end surface of the blade are in the area to be measured between the first measuring claw 206 and the main ruler 1;

[0111] The first end surface and the second end surface of the blade are brought into contact with the first measuring claw 206 and the main ruler 1 in a one-to-one correspondence;

[0112] S3. Data measurement:

[0113] Fixed knob, based on the reading window reading.

[0114] In a third aspect, this embodiment further discloses an application of a blade chord length measuring tool, which is used to measure the chord length of a multi-jointed blade.

[0115] Example 2

[0116] This embodiment discloses a measuring tool for measuring the chord length of multiple blades, such as Figure 3 As shown, compared with the measuring tool described in Example 1, the difference is that the vernier ruler 2 is a mechanical vernier ruler, the main ruler 1 is provided with a first scale area, the surface of the vernier part 201 is provided with a second scale area, the actual length δ1 of the basic unit of the first scale area is generally set to 1mm, the actual length of the basic unit of the second scale area is δ2, the number of basic units in the second scale area is n, and the maximum scale of the second scale area is K. In order to make the mechanical vernier ruler obtain the target accuracy δ, it satisfies:

[0117] δ = δ1-δ2;

[0118] δ2=K / n; wherein, when δ=0.02, n=50, K=49mm.

[0119] On the other hand, this embodiment discloses a method for measuring the chord length of a multi-blade, using the above-mentioned measuring tool, and the specific steps are the same as those in Embodiment 1.

[0120] In a third aspect, this embodiment further discloses an application of a blade chord length measuring tool, which is used to measure the chord length of a multi-jointed blade.

[0121] Example 3

[0122] This embodiment discloses a measuring tool for measuring the chord length of multiple blades, such as Figure 1 As shown, the difference compared with the measuring tool described in Example 1 is:

[0123] A main zeroing claw 102 is added to the other end of the main scale 1 protruding relative to the depth rod 205 in the length direction, and a secondary zeroing claw 202 is added to the same end of the vernier scale 2. The end surfaces of the main zeroing claw 102 and the secondary zeroing claw 202 facing each other are parallel and can abut when the reading window 203 shows the minimum number.

[0124] When the cursor part 201 is displaced toward the end of the main scale 1 where the main zero claw 102 is provided, the main zero claw 102 and the auxiliary zero claw 202 move toward each other, and the distance between the main zero claw 102 and the auxiliary zero claw 202 decreases synchronously with the length of the depth rod 205 protruding from the main scale 1, until the distance between the main zero claw 102 and the auxiliary zero claw 202 is 0; similarly, when the cursor part 201 is displaced away from the end of the main scale 1 where the main zero claw 102 is provided, the main zero claw 102 and the auxiliary zero claw 202 move backwards, and the distance between the main zero claw 102 and the auxiliary zero claw 202 increases synchronously with the length of the depth rod 205 protruding from the main scale 1.

[0125] This embodiment discloses a method for measuring the chord length of a multi-jointed blade, using the above-mentioned measuring tool, comprising the following steps:

[0126] S1. Reference zero adjustment:

[0127] The main zero-marking claw 102 and the auxiliary zero-marking claw 202 are brought into contact;

[0128] Check the reading window indication and the contact status between the first measuring claw 206 and the main ruler 1;

[0129] If the reading window shows zero and the first measuring claw 206 and the main scale 1 are in contact at the same time, the zero adjustment is completed and the device meets the requirements;

[0130] Otherwise, the processing accuracy of the device does not meet the requirements and cannot be used as a qualified measuring tool;

[0131] S2. Measurement angle adjustment:

[0132] Adjust the protruding length of the depth rod of the zero-adjusted measuring tool to a value greater than the predicted value of the chord length of the blade to be measured;

[0133] Rotate the depth rod to a suitable angle to move the first measuring claw 206 deeper into the fluid channel from the fluid channel inlet or outlet;

[0134] Rotate the depth rod again so that the first end surface and the second end surface of the blade are in the area to be measured between the first measuring claw 206 and the main ruler 1;

[0135] The first end surface and the second end surface of the blade are brought into contact with the first measuring claw 206 and the main ruler 1 in a one-to-one correspondence;

[0136] S3. Data measurement:

[0137] Fixed knob, based on the reading window reading.

[0138] In a third aspect, this embodiment further discloses an application of a blade chord length measuring tool, which is used to measure the chord length of a multi-jointed blade.

[0139] Example 4

[0140] This embodiment discloses a measuring tool for measuring the chord length of multiple blades, such as Figure 4 As shown, the difference compared with the measuring tool described in Example 3 is:

[0141] The main ruler 1 is provided with a second measuring claw 103 flush with the end surface at the protruding end of the depth rod 205. The second measuring claw 103 is flush with the end surface where it is located, and the spacing between the second measuring claw 103 and the first measuring claw 206 is the same as the spacing between the first measuring claw 206 and the main ruler 1, and both can display the chord length of the blade to be measured.

[0142] This embodiment discloses a method for measuring the chord length of a multi-jointed blade, using the above-mentioned measuring tool, comprising the following steps:

[0143] S1. Reference zero adjustment:

[0144] The main zero-marking claw 102 and the auxiliary zero-marking claw 202 are brought into contact;

[0145] Check the reading window indication and the contact status between the first measuring claw 206 and the main ruler 1;

[0146] If the reading window shows zero and the first measuring claw 206 and the main scale 1 are in contact at the same time, the zero adjustment is completed and the device meets the requirements;

[0147] Otherwise, the processing accuracy of the device does not meet the requirements and cannot be used as a qualified measuring tool;

[0148] S2. Measurement angle adjustment:

[0149] Adjust the protruding length of the depth rod of the zero-adjusted measuring tool to a value greater than the predicted value of the chord length of the blade to be measured;

[0150] Rotate the depth rod to a suitable angle to move the first measuring claw 206 deeper into the fluid channel from the fluid channel inlet or outlet;

[0151] Rotate the depth rod again so that the first end surface and the second end surface of the blade are in the area to be measured between the first measuring claw 206 and the second measuring claw 103;

[0152] The first end surface and the second end surface of the blade are brought into contact with the first measuring claw 206 and the second measuring claw 103 in a one-to-one correspondence;

[0153] S3. Data measurement:

[0154] Fixed knob, based on the reading window reading.

[0155] In a third aspect, this embodiment further discloses an application of a blade chord length measuring tool, which is used to measure the chord length of a multi-jointed blade.

[0156] Example 5

[0157] This embodiment discloses a measuring tool for measuring the chord length of multiple blades, such as Figure 5 As shown, the difference compared with the measuring tool described in Example 3 is:

[0158] The second measuring claw 103 is provided with a second hinge structure 1031 , which divides the second measuring claw 103 into two foldable parts; the first measuring claw 206 is provided with a first hinge structure 2061 , which divides the first measuring claw 206 into two foldable parts.

[0159] The rotation range of the second hinge structure 1031 and the first hinge structure 2061 is 0° to 180°.

[0160] When the second hinge structure 1031 rotates 180°, that is, when the second measuring claw 103 can rotate relatively to make the two parts horizontally coplanar, a fixing bolt is provided to ensure the fixing rigidity of the two parts of the second measuring claw 103 .

[0161] When the first hinge structure 2061 rotates 180°, that is, when the first measuring claw 206 can rotate relatively to make the two parts horizontally coplanar, a fixing bolt is provided to ensure the fixing rigidity of the two parts of the first measuring claw 206.

[0162] According to the requirement of the first end face 011 and the second end face 012 of the blade for fixing space when measuring the chord length of the blade, the first measuring claw 206 and the second measuring claw 103 are selected to be fully unfolded or folded.

[0163] This embodiment discloses a method for measuring the chord length of a multi-jointed blade, using the above-mentioned measuring tool, comprising the following steps:

[0164] S1. Reference zero adjustment:

[0165] The main zero-marking claw 102 and the auxiliary zero-marking claw 202 are brought into contact;

[0166] Check the reading window indication and the contact status between the first measuring claw 206 and the main ruler 1;

[0167] If the reading window shows zero and the first measuring claw 206 and the main scale 1 are in contact at the same time, the zero adjustment is completed and the device meets the requirements;

[0168] Otherwise, the processing accuracy of the device does not meet the requirements and cannot be used as a qualified measuring tool;

[0169] S2. Measurement angle adjustment:

[0170] Adjust the protruding length of the depth rod of the zero-adjusted measuring tool to a value greater than the predicted value of the chord length of the blade to be measured;

[0171] Rotate the depth rod to a suitable angle to move the first measuring claw 206 deeper into the fluid channel from the fluid channel inlet or outlet;

[0172] Rotate the depth rod again so that the first end surface and the second end surface of the blade are in the area to be measured between the first measuring claw 206 and the second measuring claw 103;

[0173] The first end surface and the second end surface of the blade are brought into contact with the first measuring claw 206 and the second measuring claw 103 in a one-to-one correspondence;

[0174] S3. Data measurement:

[0175] Fixed knob, based on the reading window reading.

[0176] In a third aspect, this embodiment further discloses an application of a blade chord length measuring tool, which is used to measure the chord length of a multi-jointed blade.

[0177] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A measuring tool for measuring the chord length of multiple blades, characterized in that: include: Main scale and vernier scale; The vernier scale is provided with a vernier portion, and the vernier portion can slide freely relative to the main scale in the length direction of the main scale; The vernier part is provided with a reading window capable of displaying the displacement change of the vernier part relative to the main scale; The cursor part is fixedly connected with a depth rod, and the depth rod can slide freely relative to the main scale in the length direction of the main scale and protrude from the main scale; A first measuring claw is disposed at the end of the depth rod, and a side of the first measuring claw close to the main scale is parallel to an end surface of the depth rod protruding from the main scale.

2. The multi-blade chord length measuring tool according to claim 1, characterized in that: The vernier part is arranged around the main scale, and the vernier part and the main scale are connected through a pulley.

3. The multi-blade chord length measuring tool according to claim 2, characterized in that: The pulleys are symmetrically arranged on both sides of the main scale.

4. The multi-blade chord length measuring tool according to claim 3 is characterized in that: A slide groove is provided inside the main ruler, and the depth rod can slide relative to the main ruler in the slide groove.

5. The multi-blade chord length measuring tool according to claim 4, characterized in that: A main zeroing claw is provided at the other end of the main scale in the length direction relative to the protruding end of the depth rod, and a secondary zeroing claw is provided at the same end of the vernier scale; The end surfaces of the main zero-marking claw and the auxiliary zero-marking claw facing each other are parallel and can abut against each other when the reading window shows the minimum value.

6. The multi-blade chord length measuring tool according to claim 5, characterized in that: A second measuring claw is provided at one end of the depth rod protruding in the length direction of the main scale, and the second measuring claw is flush with the end surface of the depth rod protruding from the main scale.

7. The multi-blade chord length measuring tool according to claim 6, characterized in that: The first measuring claw and the second measuring claw are foldable structures.

8. The multi-blade chord length measuring tool according to claim 7, characterized in that: The cursor part is also provided with a fixing knob.

9. A method for measuring the chord length of multiple blades, characterized in that: Use the multi-blade chord length measuring tool described in any one of claims 1 to 8.

10. An application of a blade chord length measuring tool, characterized in that: The chord length measuring tool for measuring multiple blades according to any one of claims 1 to 8 is used to measure the chord length of multiple blades.

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