Digitized inside micrometer for airplane reaming measurement

Abstract

The invention relates to a digital inside micrometer for aircraft reaming measurement, and belongs to the technical field of aircraft assembly detection. By investigating and analyzing an existing detection method and an existing detection tool, in actual work, the measurement workload is large, the measurement efficiency is low, the perpendicularity measured by the tool cannot be guaranteed, the influence of factors such as subjective judgment and an operation method is large, and due to the adverse factors, the production efficiency is low, and the measurement error of the reaming hole diameter is likely to be caused. In the product assembling process, an inspector adopts the intelligent measuring device to implement the novel measuring method, and the intelligent measuring device is widely applied to measurement of reamed holes of airplane parts and assembly parts and realizes high-efficiency and high-precision measurement of the quality of the reamed holes of the airplane.

Description

Technical Field

[0001] The invention relates to a digital internal diameter micrometer used for measuring aircraft reaming holes, belonging to the technical field of aircraft assembly detection. Background Art

[0002] There are hundreds of thousands of fasteners in aircraft assembly, and they are of various types and sizes. Fasteners are mainly concentrated in the threaded connection method. Bolts of various types are used to connect various parts through reaming holes to achieve the overall assembly and fixation of the aircraft. When processing the aperture, the operator needs to use a special reamer to perform multi-stage reaming. Finally, the inner diameter value of the reamed hole must meet the design requirements. If the aperture of the reamed hole is too large or too small, it will cause destructive stress changes between the fasteners and the aircraft body parts. Through repeated interactions, cracks will occur around the reamed hole, which will eventually affect the aircraft body structure. In order to ensure the stable connection of the structure during aircraft flight and avoid serious quality problems, there are high requirements for the processing accuracy of the hole before screwing.

[0003] Reaming is one of the finishing methods for holes. Reaming is carried out after the preliminary drilling is completed to ensure the smoothness and tolerance requirements of the hole. At present, there are two ways to measure aircraft reamed holes: qualitative measurement and quantitative measurement. The qualitative measurement method is that after the reamed hole is made, the inspector uses a plug gauge to measure. Since the aperture measurement of the reamed hole is a range value, the plug gauge is divided into a through gauge and a stop gauge. When measuring the reamed hole, the through end of one side of the plug gauge can pass through the reamed hole, while the other side cannot pass through the reamed hole. The reamed hole is judged to be qualified. If the through end of the plug gauge cannot pass through the reamed hole, the aperture is judged to be small. If the stop end of the plug gauge can pass through the reamed hole, the aperture is judged to be large. The quantitative measurement method is that after reaming, the inspector uses an inside diameter micrometer to measure. During the aircraft assembly process, the reaming requirements for the finishing areas of large components are more stringent, and the specific inside diameter of the hole needs to be measured and recorded. In accordance with the relevant requirements of the process regulations, the inspector uses an inside diameter micrometer to measure the hole diameter. The gauge needs to be adjusted to zero before measurement. During measurement, the inspector inserts the probe of the micrometer into the hole to ensure that the probe is perpendicular to the surface of the part.

[0004] The qualitative measurement method using a plug gauge can determine whether the hole is qualified. However, there are a large number of reaming holes in aircraft assembly. The manual plug gauge measurement method requires measuring the through end and the stop end of each hole, which is cumbersome and inefficient. At the same time, when measuring a small hole, the plug gauge will be stuck due to friction. On the one hand, it increases the labor intensity of the inspectors, and on the other hand, it is easy to cause scratches on the inner wall of the hole. The quantitative measurement method using a micrometer is complicated and cumbersome. The meter needs to be adjusted before measurement. During measurement, due to manual operation, it is difficult to ensure the verticality of the measurement, which is easy to cause measurement errors. Since the parts have a certain thickness, the probe of the micrometer can only measure the inner diameter value of a certain section in the hole each time. If the hole is fully measured, multiple measurements must be carried out, and the measurement accuracy is not ideal and the efficiency is low. At the same time, manual reading of the meter is required after measurement, so there are errors in the overall measurement and the measurement is time-consuming. In view of the above problems, there is a need for an intelligent inner diameter measuring device that can perform qualitative and quantitative measurements at the same time to improve measurement accuracy and efficiency. Summary of the invention

[0005] The present invention provides a digital measuring device for the inner diameter of reaming holes in aircraft assembly for on-site inspectors, so as to solve the problems of low measurement accuracy, low efficiency and high labor intensity of the inner diameter values ​​of reaming holes in aircraft parts and assembly parts.

[0006] The technical problem solved by the present invention is achieved by adopting the following technical solutions:

[0007] A digital internal micrometer for measuring aircraft reaming holes is an intelligent device used in body assembly aperture detection. The device uses a high-precision displacement sensor with a range of mm and a precision probe structure for measurement. According to the design requirements, the algorithm calculation is realized through single-chip computer programming, and the qualitative and quantitative measurements of the inner diameter of the reaming hole can be realized at the same time. Qualitative measurement can determine whether the inner diameter value of the reaming hole meets the aperture range requirements. If it exceeds the upper and lower limits of the aperture, the measuring device will give an alarm display. Compared with the previous qualitative plug gauge tools, the measurement efficiency is improved and the labor intensity of the inspectors is reduced. Quantitative measurement can measure the specific value of the inner diameter of the reaming hole, and the measurement accuracy can reach 0.001mm. It is used for reaming hole measurement of important parts of the body structure. Compared with the previous micrometer tools, the measurement accuracy and efficiency are improved.

[0008] A digital internal diameter micrometer for measuring aircraft reaming holes, the structural diagram is shown in the attached figure. Figure 1 , Attachment Figure 2As shown, the device mainly includes a precision probe, a support base, a locking screw, a sleeve, a spring, a clamping sleeve, a clamping bolt, a displacement sensor, an alarm indicator light, a display screen, a screw, a box cover, a mode conversion button, a reset button, a power button, a charging connector, a bottom box, a data connector, a control module, a transformer module, a power module, a signal amplifier, an AD conversion module and a calibration gauge. Among them, the precision probe, the support base, the locking screw, the sleeve, the spring, the clamping sleeve, the clamping bolt, the screw, the box cover, the bottom box, and the calibration gauge constitute the mechanical structure part of the aircraft reaming digital internal diameter micrometer, and the displacement sensor, the alarm indicator light, the display screen, the mode conversion button, the reset button, the power button, the charging connector, the data connector, the control module, the transformer module, the power module, the signal amplifier, and the AD conversion module constitute the electronic control part of the aircraft reaming digital internal diameter micrometer.

[0009] The precision probe mainly measures through the 4 balls on the probe. When the precision probe is inserted into the inner wall of the reaming hole to be measured, the balls are squeezed by the inner wall of the reaming hole and compressed inward. At the same time, the balls squeeze the internal connecting rod of the precision probe, causing it to move linearly upward. When the precision probe is pulled out of the reaming hole, the balls are reset, and at the same time, the internal connecting rod of the precision probe moves linearly downward. The linear movement of the internal connecting rod up and down will drive the head of the displacement sensor to expand and contract, thereby generating a change in the displacement electrical signal of the sensor. The precision probe has several models of φ5, φ6, φ7, φ8, and φ10. The probe model can be replaced according to the aperture value to be measured. The casing is a hollow tube made of stainless steel with an inner diameter of 8mm, which is used to connect the displacement sensor and the precision probe. The top of the precision probe has an external thread, which is connected with the internal thread of the sleeve. The displacement sensor is inserted into the sleeve at the other end. When the head of the displacement sensor contacts the internal connecting rod of the precision probe, the clamping sleeve is put on the outside of the sleeve. The clamping sleeve has a φ4 internal thread hole and is screwed with a clamping bolt with a φ4 external thread. By tightening the clamping bolt, the sleeve clamps the displacement sensor. The support base is put on the outside of the precision probe and the sleeve. During measurement, the end face of the support base contacts the surface of the part with the reamed hole. The purpose is to ensure the verticality of the precision probe and ensure the accuracy of the measurement. There is a φ3 internal thread hole on the sleeve, the support base has a long groove with a width of 3mm, and the locking screw has a φ3 external thread. By tightening the locking screw on the sleeve, the locking screw can limit the movement range of the support base during measurement. The spring is placed between the support base and the clamping sleeve. During measurement, the end face of the support base contacts the surface of the parts around the reaming hole. The inspector presses the clamping sleeve with his hand to achieve the measurement of the ball of the precision probe from top to bottom on the inner wall of the reaming hole. The measurement range is wide. When the inspector no longer presses the clamping sleeve, the precision probe returns to its original position due to the elastic force of the spring. The box cover and bottom box are made of PLA material through 3D printing, which are used to place and fix various electronic components, and are finally connected by 4 screws. The calibration gauge is a steel circular ring gauge, such as Figure 5As shown, before measurement, the precision probe is inserted into the calibration gauge hole to set the measurement reference. The size specification of the calibration ring gauge corresponds to the hole diameter to be measured, and the ring gauge accuracy is 0.001mm.

[0010] The control box is mainly equipped with control module, transformer module, power module, signal amplifier, AD conversion module, such as Figure 2 As shown. Among them, the control module is the core module of the entire control system, which is used to receive and process sensor signals and output instructions to control other modules to perform corresponding work. The signal amplifier is connected to the displacement sensor through a cable. When the precision probe is measuring, the internal ball and connecting rod will drive the displacement sensor to produce displacement changes, which will be converted into corresponding voltage or current signals. The signal amplifier can amplify the voltage or current of the sensor signal to facilitate signal processing, analysis and control, and improve the accuracy and stability of the electrical signal. After passing through the signal amplifier, the electrical signal continues to be transmitted to the AD conversion module. The 16-bit high-precision analog-to-digital conversion module used in the AD conversion module is used to convert the sensor analog signal into a digital signal. The measurement resolution can reach 0.0005mm, which meets the measurement requirements. The AD conversion module transmits the converted signal to the control module for processing. The power module uses a 9V rechargeable lithium battery to power all electronic components. Since the power supply voltage of other modules is 5V DC voltage, a transformer module is required for voltage conversion. The transformer module is MP1584EN model, which can realize the DC voltage 9V-5V conversion function, and the voltage and current output are stable. The charging connector uses a USB Type-C interface, which can be used to charge the power module directly via a data cable, which is convenient and fast. The data connector uses a Mini USB interface, which can connect the computer and the control module via a data cable, and the program can be replaced and imported according to the actual measurement requirements.

[0011] The alarm indicator can determine whether the reaming aperture is within the specified range. It is mainly used for qualitative measurement of reaming. According to the range requirements of the aperture value, the upper and lower aperture values ​​of the measurement are formulated through software programming. When the measured data value is lower than the lower limit or higher than the upper limit, it means that the aperture value of the reaming does not meet the requirements. At this time, the control module drives the alarm indicator to light up red. On the contrary, when the measured data value is between the lower limit and the upper limit, the aperture of the reaming is qualified, and the control module drives the alarm indicator to light up green. The display screen uses a 1.3-inch OLED screen, which is mainly used for quantitative measurement of reaming. For reaming important parts of the docking area of ​​large components, the specific aperture value of the reaming needs to be measured. Through serial communication between the control module and the display screen, the calculated aperture value can be displayed on the display screen, which is convenient for inspection personnel to record. The power button uses a metal self-locking switch to open and close the control box. Before turning on the power button, the precision probe needs to be inserted into the calibration gauge. The mode conversion button uses a metal self-reset switch to switch the aperture size mode. After turning on the power button, according to the actual measured aperture size, the mode conversion button is used to switch to select the apertures of φ5, φ6, φ7, φ8, and φ10 to achieve multi-aperture reaming measurement. The reset button also uses a metal self-reset button to restart the program. When the measurement part is changed and the reaming is changed, the reset button can be used to recalibrate the measurement.

[0012] Beneficial effects of the present invention:

[0013] Through the investigation and analysis of existing detection methods and detection tools, it is found that in actual work, there are many problems such as large measurement workload, low measurement efficiency, lack of guarantee of tool measurement verticality, and great influence of factors such as subjective judgment and operation methods. The above unfavorable factors have resulted in low production efficiency and are prone to measurement errors of reaming hole diameters. The intelligent device uses a precision probe with a high-precision displacement sensor to measure reaming holes. Through program algorithms, it can simultaneously realize qualitative and quantitative inspections of reaming holes. During the product assembly process, inspectors use this intelligent measuring device to implement the above new measurement method, which is widely used in the measurement of reaming holes in aircraft parts and assembly parts, and achieves efficient and high-precision measurement of aircraft reaming hole quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of a digital internal micrometer for aircraft reaming measurement;

[0015] Figure 2 This is the internal module distribution diagram of the digital internal micrometer control box;

[0016] Figure 3 This is a schematic diagram of the internal structure of a digital internal micrometer;

[0017] Figure 4 This is a schematic diagram of the structure of a digital internal micrometer probe;

[0018] Figure 5 Schematic diagram of the digital inside micrometer calibration gauge.

[0019] Among them, 1-precision probe, 2-support base, 3-locking screw, 4-sleeve, 5-spring, 6-clamping sleeve, 7-clamping bolt, 8-displacement sensor, 9-alarm indicator light, 10-display screen, 11-screw, 12-upper box cover, 13-mode conversion button, 14-reset button, 15-power button, 16-charging connector, 17-bottom box, 18-data connector, 19-control module, 20-transformer module, 21-power module, 22-signal amplifier, 23-AD conversion module, 24-calibration gauge. DETAILED DESCRIPTION

[0020] Embodiment 1:

[0021] Taking Φ6H9 reaming as an example, the qualitative inspection method is as follows:

[0022] Step 1: Tool preparation. Select a φ6 precision probe 1 and a sleeve 4 to connect and fix, and install the support base 2 and locking screw 3, and select the corresponding calibration gauge 24, the gauge aperture value is 6.000mm.

[0023] Step 2: Zero calibration. Before measuring, first insert the φ6 precision probe 1 into the calibration gauge 24, turn on the power button 15, and the display screen 10 will display the words "Select aperture". Select the qualitative aperture 6.000mm mode through the mode conversion button 13, and the qualitative inspection of the φ6H9 reaming can be carried out.

[0024] Step 3: Measurement. After completing the calibration of the φ6 precision probe 1, insert the precision probe 1 into the reaming hole to be measured, and make the lower end surface of the support base 2 contact the reaming part to ensure the verticality of the measurement. The inspector presses the clamping sleeve 6 by hand to make the ball of the precision probe 1 pass through the entire reaming hole from top to bottom.

[0025] Step 4: Discrimination. During the entire measurement process, the alarm indicator light 9 on the box cover 12 is mainly used for differentiation. If the alarm indicator light 9 is green, it means that the aperture value of the reaming hole is within the range of the lower limit and the upper limit, that is, the Φ6H9 reaming hole is qualified. If the alarm indicator light 9 is red, it means that the aperture value of the reaming hole is less than the lower limit or greater than the upper limit, that is, the Φ6H9 reaming hole is unqualified.

[0026] Step 5: Follow the above steps to perform a qualitative inspection of the next reaming hole and make a record.

[0027] Embodiment 2:

[0028] Taking Φ6H9 reaming as an example, the quantitative inspection method is as follows:

[0029] Step 1: Tool preparation. Select a φ6 precision probe 1 and a sleeve 4 to connect and fix, and install the support base 2 and locking screw 3, and select the corresponding calibration gauge 24, the gauge aperture value is 6.000mm.

[0030] Step 2: Zero calibration. Before measuring, first insert the φ6 precision probe 1 into the calibration gauge 24, turn on the power button 15, and the display screen 10 will display the words "Select aperture". Select the quantitative aperture 6.000mm mode through the mode conversion button 13, and the quantitative inspection of the φ6H9 reaming can be carried out.

[0031] Step 3: Measurement. After completing the calibration of the φ6 precision probe 1, insert the precision probe 1 into the reaming hole to be measured, and make the lower end surface of the support base 2 contact the reaming part to ensure the verticality of the measurement. The inspector presses the clamping sleeve 6 by hand to make the ball of the precision probe 1 pass through the entire reaming hole from top to bottom.

[0032] Step 4: Record the value. During the entire measurement process, the control module 19 will calculate the inner diameter value of the currently measured reaming hole in real time and display the value through the display screen 10. The inspector can record the hole diameter value at any position during the measurement process, and the value is accurate to 0.001mm.

[0033] Step 5: Follow the above steps to perform a quantitative inspection of the next reaming hole and make a record.

Claims

1. A digital internal micrometer for measuring aircraft reaming, characterized in that: It comprises a precision measuring head (1), a supporting base (2), a displacement sensor (8), an alarm indicator light (9), a display screen (10), screws (11), a box cover (12), a mode switching button (13), a power module (21), a signal amplifier (22), an AD conversion module (23) and a calibration gauge (24); The precision measuring head (1), the supporting base (2), the locking screw (3), the sleeve (4), the spring (5), the clamping sleeve (6), the clamping bolt (7), the screw (11), the box cover (12), the bottom box (17), and the calibration gauge (24) constitute the mechanical structure part of the aircraft reaming digital internal diameter micrometer, and the displacement sensor (8), the alarm indicator light (9), the display screen (10), the mode conversion button (13), the reset button (14), the power button (15), the charging connector (16), the data connector (18), the control module (19), the transformer module (20), the power module (21), the signal amplifier (22), and the AD conversion module (23) constitute the electrical control part of the aircraft reaming digital internal diameter micrometer; The top of the precision measuring head (1) is provided with an external thread, which is matched and connected with the internal thread of the sleeve (4). The other end of the displacement sensor (8) is inserted into the sleeve (4). When the head of the displacement sensor (8) contacts the internal connecting rod of the precision measuring head (1), the clamping sleeve (6) is sleeved on the outside of the sleeve (4). The clamping sleeve (6) has an internal thread hole of φ4 and is screwed with a clamping bolt (7) with an external thread of φ4. By tightening the clamping bolt (7), the sleeve (4) clamps the displacement sensor (8). The support base (2) is sleeved on the outside of the precision measuring head (1) and the sleeve (4). The sleeve (4) is provided with an internal threaded hole of φ3, the support base (2) is provided with a long groove of 3 mm in width, and the locking screw (3) is provided with an external thread of φ3, and the locking screw (3) is tightened on the sleeve (4); The spring (5) is placed between the support base (2) and the clamping sleeve (6). During measurement, the end face of the support base (2) contacts the surface of the part around the reaming hole. The inspector presses the clamping sleeve (6) by hand. When the inspector stops pressing the clamping sleeve (6), the precision measuring head (1) returns to its original position due to the elastic force of the spring (5). The calibration gauge (24) is a steel circular ring gauge. Before measurement, the precision probe (1) is inserted into the hole of the calibration gauge (24) to set the measurement reference. The size specification of the calibration ring gauge corresponds to the hole diameter to be measured, and the ring gauge accuracy is 0.001mm.

2. A digital internal micrometer for measuring aircraft reaming according to claim 1, characterized in that: The precision probe (1) is measured by four balls on the probe. When the precision probe (1) is inserted into the inner wall of the reaming hole to be measured, the balls are squeezed by the inner wall of the reaming hole and compressed inward. At the same time, the balls squeeze the internal connecting rod of the precision probe (1), causing it to move linearly upward. When the precision probe (1) is pulled out of the reaming hole, the balls are reset, and at the same time, the internal connecting rod of the precision probe (1) moves linearly downward. The linear movement of the internal connecting rod up and down drives the head of the displacement sensor (8) to expand and contract, thereby generating a displacement electrical signal change of the sensor.

3. A digital internal micrometer for measuring aircraft reaming according to claim 1 or 2, characterized in that: The precision measuring head (1) has models of φ5, φ6, φ7, φ8 and φ10, and the measuring head model is changed according to the aperture value to be measured.

4. A digital internal micrometer for measuring aircraft reaming according to claim 1 or 2, characterized in that: The sleeve (4) is a hollow tube made of stainless steel with an inner diameter of 8 mm, and is used for connecting the displacement sensor (8) and the precision measuring head (1).

5. A digital internal micrometer for measuring aircraft reaming according to claim 3, characterized in that: The sleeve (4) is a hollow tube made of stainless steel with an inner diameter of 8 mm, and is used for connecting the displacement sensor (8) and the precision measuring head (1).

6. A digital internal micrometer for measuring aircraft reaming according to claim 1, 2 or 5, characterized in that: The box cover (12) and the bottom box (17) are made of PLA material by 3D printing, and are used to place and fix various electronic components, and are finally connected by four screws (11).

7. A digital internal micrometer for measuring aircraft reaming according to claim 3, characterized in that: The box cover (12) and the bottom box (17) are made of PLA material by 3D printing, and are used to place and fix various electronic components, and are finally connected by four screws (11).

8. A digital internal micrometer for measuring aircraft reaming according to claim 4, characterized in that: The box cover (12) and the bottom box (17) are made of PLA material by 3D printing, and are used to place and fix various electronic components, and are finally connected by four screws (11).

9. A digital internal micrometer for measuring aircraft reaming according to claim 1, characterized in that: The signal amplifier (22) is connected to the displacement sensor (8) via a cable. When the precision probe (1) is measuring, the internal ball and connecting rod drive the displacement sensor (8) to produce a displacement change. After the electrical signal passes through the signal amplifier (22), it is continuously transmitted to the AD conversion module (23). The AD conversion module (23) uses a 16-bit high-precision analog-to-digital conversion module for converting the sensor analog signal into a digital signal.

10. A digital internal micrometer for measuring aircraft reaming according to claim 1, characterized in that: The power module (21) adopts a 9V rechargeable lithium battery, and the transformer module (20) is of the MP1584EN model.

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