CN112050770B

CN112050770B - Thickness detection device

Info

Publication number: CN112050770B
Application number: CN202010996395.0A
Authority: CN
Inventors: 赵谦; 王克; 张立泉; 李超; 张有信
Original assignee: Nanjing Fiberglass Research and Design Institute Co Ltd
Current assignee: Nanjing Fiberglass Research and Design Institute Co Ltd
Priority date: 2020-09-21
Filing date: 2020-09-21
Publication date: 2022-03-18
Anticipated expiration: 2040-09-21
Also published as: CN112050770A

Abstract

A thickness detection device comprises a fixed support frame, an X-axis linear displacement mechanism, a Z-axis linear displacement mechanism, a linear displacement sensor, a pressure head, a PLC (programmable logic controller) and an upper computer; the X-axis linear displacement mechanism is arranged on the fixed frame and can move linearly along the fixed frame; the Z-axis linear displacement mechanism is connected with the X-axis linear displacement mechanism and can move up and down linearly along the X-axis linear displacement mechanism; the linear displacement sensor is connected to the Z-axis linear displacement mechanism; the lower end of the linear displacement sensor is connected with a pressure head; the PLC is used for controlling the movement of the X-axis linear displacement mechanism, the Z-axis linear displacement mechanism and the linear displacement sensor and transmitting test data to the upper computer, and the upper computer calculates the test data of the linear displacement sensor to obtain the current online thickness of the fabric. The invention can realize the on-line thickness detection of the large-size revolving body variant surface three-dimensional woven preform.

Description

Thickness detection device

Technical Field

The invention belongs to the technical field of textile machinery, and particularly relates to a thickness detection device.

Background

The manufacture of three-dimensional woven prefabricated bodies is a novel weaving technology, yarn bundles are distributed in a three-dimensional space along two mutually vertical directions of a warp direction and a weft direction and are mutually interwoven to form an integral structure, and a composite material member made of the yarn bundles as a high-performance composite material reinforcement has the advantages of light weight, high strength, excellent mechanical property and the like, is widely applied in various fields of aerospace, national defense and military industry, transportation, energy and the like at present, and is continuously expanded to the civil field.

The thickness of the three-dimensional woven preform on machine is an important influence factor in preform forming and manufacturing, and is directly related to the forming size, mechanical property and functional requirements of the preform, particularly the thickness of the large-size revolving body variant surface three-dimensional woven preform is difficult to directly measure, and a large-size thickness detection device needs to be designed. In the prior art, the three-dimensional woven preform with the large-size revolving body variable-profile surface is difficult to accurately measure in the online manufacturing process.

Disclosure of Invention

The invention aims to provide a thickness detection device for measuring a deformed three-dimensional woven preform in online manufacturing.

The technical solution for realizing the purpose of the invention is as follows:

a thickness detection device comprises a fixed frame, an X-axis linear displacement mechanism, a Z-axis linear displacement mechanism, a linear displacement sensor, a pressure head, a PLC (programmable logic controller) and an upper computer;

the X-axis linear displacement mechanism is arranged on the fixed frame and can move linearly along the fixed frame; the Z-axis linear displacement mechanism is connected with the X-axis linear displacement mechanism and can move up and down linearly along the X-axis linear displacement mechanism; the linear displacement sensor is connected to the Z-axis linear displacement mechanism;

the lower end of the linear displacement sensor is connected with a pressure head; the PLC is used for controlling the movement of the X-axis linear displacement mechanism, the Z-axis linear displacement mechanism and the linear displacement sensor and transmitting test data to the upper computer, the upper computer calculates the test data of the linear displacement sensor, and the difference is obtained according to the difference between the mold measuring point and the initial position of the special pressure head and the difference between the fabric measuring point and the initial position of the special pressure head, so that the current online thickness of the fabric is obtained.

Compared with the prior art, the invention has the following remarkable advantages:

(1) the invention can realize the on-line thickness detection of the large-size revolving body deformation surface three-dimensional woven preform and can effectively meet the precision requirement of a measuring device.

(2) The measuring contact surface of the special pressure head of the sensor is an arc, the influence on the surface quality of the fabric can be effectively reduced, the measuring point of the revolving body can be effectively positioned, the specific size parameter of the pressure head can be determined according to the molded surface of the measured position, the specificity is realized, meanwhile, the pressure head can be replaced, and the optional position of the molded surface can be detected.

(3) The X-axis linear displacement mechanism and the Z-axis linear displacement mechanism are driven by stepping motors, can detect the thickness of multiple points of the large-size revolving body variant surface three-dimensional woven preform, and can accurately return to the previous measuring point according to the feedback of the encoder; the Z-axis linear displacement mechanism realizes the vertical and straight movement of the displacement sensor, expands the measuring range of the displacement sensor and can reserve the space for the staff to operate on the machine.

(4) The detection device expands the measuring range of the displacement sensor and can be suitable for weaving the prefabricated body with large thickness variation.

Drawings

Fig. 1 is a front view of a wire thickness detection device provided in the embodiment.

Fig. 2 is a top view of a line thickness detection apparatus provided in the embodiment.

Fig. 3(a-b) are diagrams of a process of testing the linear displacement sensor testing mold and the fabric on the mold, respectively.

Fig. 4(a-b) are diagrams of indenter and fabric convexity and concavity test procedures, respectively.

FIG. 5 is a front view of the X-axis linear displacement mechanism.

FIG. 6 is a top view of the X-axis linear displacement mechanism.

FIG. 7 is a front view of the Z-axis linear displacement mechanism.

FIG. 8 is a rear view of the Z-axis linear displacement mechanism.

Detailed Description

The invention is further described with reference to the following figures and embodiments.

Referring to fig. 1 and 2, the thickness detection device of the present embodiment includes a fixing frame 1, an X-axis linear displacement mechanism 30, a Z-axis linear displacement mechanism 10, a linear displacement sensor 50, a special indenter 60, a PLC controller, and an upper computer;

the X-axis linear displacement mechanism 30 is arranged on the fixed frame 1 and can horizontally and linearly move along the fixed frame 1; the Z-axis linear displacement mechanism 10 is connected with the X-axis linear displacement mechanism 30 and can move linearly up and down along the X-axis linear displacement mechanism 30; the linear displacement sensor 50 is connected to the Z-axis linear displacement mechanism 10 through a mounting member 51; the lower end of the linear displacement sensor 50 is connected with a special pressure head 60; the section of the lower end of the special pressure head 60 is triangular, the bottom of the triangle is a circular arc, and the radius of the circular arc is R; the linear displacement sensor 50 is a contact resistance type displacement sensor and is used for transmitting test data to the PLC controller, the PLC controller is used for controlling the movement of the X-axis linear displacement mechanism 30, the Z-axis linear displacement mechanism 10 and the linear displacement sensor 50 and transmitting the test data to the upper computer, and the upper computer calculates the test data to obtain the current online thickness of the fabric 3.

The thickness measuring process is as shown in fig. 3(a-b), before the measurement starts, the control system sends signals according to the program, controls the X-axis linear displacement mechanism to reach a specified measuring point and controls the Z-axis linear displacement mechanism to move to a specified initial height, then controls the linear displacement sensor 50 to start working, extends out of the sliding rod until the special pressure head 60 contacts with the die 2, detects the distance between the die 2 and the initial height of the special pressure head 60 at the measuring point, records as X1, and transmits the result to the PLC controller and transmits the result to the upper computer. When the thickness of the fabric 3 is measured, the process is repeated, when the special press head 60 is in contact with the fabric 3 on the mould 2, the distance of the initial height of the special press head 60 at the measuring point of the fabric 3 is detected and recorded as X2, the result is transmitted to the upper computer to be stored, and the upper computer calculates X1-X2, namely the current online thickness of the fabric 3. After the X-axis linear displacement mechanism detects one point, the control system controls the X-axis linear displacement mechanism to move to another detection point until all detection points of the current measurement are detected and return to the initial position, the Z-axis linear displacement mechanism is reset and lifted after all detection points are detected so as to reserve space for staff to operate, and the linear sensor 50 is reset after each detection is completed.

The special pressure head 60 is arranged on the linear displacement sensor in the measuring device and is in threaded connection with the linear displacement sensor, the special pressure head 60 is in a linear shape and is positioned in the horizontal tangential direction of the top point of the die 2, and the rotation direction of a sliding rod of the linear displacement sensor 50 is limited, so that the pressure head 60 can be ensured not to shake along the Y axis completely, the whole device is not required to be accurately positioned in the Y direction, and the measuring point can be ensured to be positioned at the top point of the revolving body all the time. The cross section of the lower end of the pressure head 60 is ensured to be approximate to an isosceles triangle, and as shown in figure 4(a-b), the included angles between the two sides of the triangle and the special-shaped fabric are respectively theta₁And theta₂The measuring contact surface at the triangular bottom of the pressure head is an arc with the radius of R, so that point or line contact with the surface of the prefabricated part is guaranteed, the measuring result is more accurate, and the surface yarn of the fabric 3 is guaranteed not to be damaged. Because the surface of the fabric 3 is in a concave-convex texture type, the measuring point needs to be ensured to be measured on the convex surface,a relatively accurate value can be obtained, and due to a straight line error in the warp and weft directions of the fabric (for example, the same straight line in the weft direction basically keeps a thickness, and the thickness gradually increases with the angle theta in the radial direction), a concave surface contact situation may occur when the same point is measured and positioned, as shown in fig. 4(b), if the requirement of the measurement accuracy epsilon needs to be met, the following requirements need to be met: 1. in order to accurately position the contact point, the distance of Rsin (theta) needs to be reversely compensated for positioning the X axis; 2. the radius of the pressure head R needs to satisfy the following conditions:

where W is the chord length of the concave surface of the fabric 3.

The movement direction of the X-axis linear displacement mechanism 30 is parallel to the axial direction of the die 2, and before each time, the positioning of the measuring reference needs to be checked. The positioning of any measuring point is to calculate the rotation angle of the motor and the pulse number of a motor encoder according to the X axial distance between the measuring point and the reference, and the PLC communicates the data to the motor driver to realize the accurate positioning of the motor, so that the measuring probe can reach the accurate measuring position, and the positioning accuracy is very high. Because the measured molded surface is a deformation surface, the inclination angle of the area where the measuring point is located is assumed to be theta, and the bottom of the pressure head is an arc with the radius of R when the fabric is measured, the contact point of the pressure head is the lowest point of the arc surface of the pressure head, the contact point is the tangent point of the arc surface of the pressure head and the fabric, and the distance of Rsin (theta) is more increased on the X axial position than the lowest point of the arc surface of the pressure head, so that the distance-Rsin (theta) between the measuring point and the reference point is needed when the pulse number of a computer encoder is measured, and the positioning can be more accurate.

As shown in fig. 5 and 6, the schematic diagram of the X-axis linear displacement mechanism 30 of the thickness detection device mainly includes a first stepping motor 31, a reversing speed reducer 32, a first micrometer 33, a speed reducer mounting plate 34, a first gear 35 and a first rack 36, a first linear guide rail 37 and a first slider 38, a mounting plate 39, a first moving sliding table 40, a first stroke limiting plate 41, and a first peripheral mounting platform 42;

the mounting plate 39 is vertically arranged and fixed on the fixed frame 1 through threaded connection, and the speed reducer mounting plate 34 is fixed on the mounting plate 39; a first slide block 38 is fixed on the mounting plate 39; a first linear guide rail 37 and a first rack 36 are fixed on the first movable sliding table 40; a first slider 38, which is engaged with the first linear guide 37, is slidable in the slider 35; the reversing reducer 32 and the first micrometer 33 are fixed on the reducer mounting plate 34, the input side of the reversing reducer 32 is connected with the first stepping motor 31, and the output side of the reversing reducer is connected with the first gear 35 through a key; the first gear 35 is engaged with the first rack 36; first stroke limiting plate 41 is all equipped with at first removal slip table 40 both ends, prevents that device rectilinear movement from surpassing maximum stroke, plays mechanical protection effect. The outer side of the movable sliding table is connected with a first peripheral installation platform 42; the decelerator 32 and the first micrometer 33 are connected side by side to the upper side of the decelerator mounting plate 34. Near the front center of the mounting

plate

39, 2 groups of 4 first guide rail sliders 38 and two first linear guide rails 37 are fixedly distributed, and the principle of the whole device is as follows: the first stepping motor 31 is driven by the reversing reducer 32, the first gear 35 is in transmission with the first rack 36, and the first linear guide rail 37 is guided by the first sliding block 38, so that the first movable sliding table 40 and the first peripheral installation platform 42 can move linearly. Wherein the adjustment position is corrected by means of the first micrometer 33 micromotion mechanism. The device can realize accurate linear movement in the X-axis direction.

As shown in fig. 7 and 8, the schematic diagram of the Z-axis linear displacement mechanism 10 of the thickness detection device mainly includes a second stepping motor 11, a speed reducer 12, a commutator 13, a second micrometer 14, a mounting plate 15, a second gear 16, a second rack 17, a second precise linear guide rail 18, a second slider 19, a second stroke limiting plate 20, a second moving sliding table 21, a second external mounting platform 22, and an extension platform 23;

the mounting plate 15 is vertically placed and fixed on the first peripheral mounting platform 42 of the X-axis linear displacement mechanism 30; the side surface of the commutator 13 is fixed on a mounting plate 15, the output side is connected with a second gear 16, the position of the input side is 90 degrees of anticlockwise transformation of the output side, the input side is connected with the output side of a speed reducer 12, the input side of the speed reducer 12 is connected with a second stepping motor 11, a second micrometer 14 is positioned at the rear side of the speed reducer 12 and connected with a right-angled bulge on the mounting plate 15, the axial direction of the second micrometer 14 is consistent with the output axial direction of the speed reducer 12, 2 groups of 4 guide rail second sliding blocks 19 are fixedly distributed on the mounting plate 15, and two second precise linear guide rails 18 vertically slide in the guide rail second sliding blocks; each second precise linear guide rail 18 is respectively matched with two second sliding blocks 19, the linear guide rails 18 can slide in the second sliding blocks 19, the second rack 17 is installed on one side, facing the second gear 16, of the second movable sliding table 21, the second gear 16 is meshed with the second rack 17, and second stroke limiting plates 20 are installed at two ends of the second movable sliding table 21 to ensure that the sliding tables cannot exceed strokes; the outer side of the movable sliding table 21 is connected with a second external mounting platform 22 for connecting with other parts, and the second external mounting platform 22 is connected with an expansion platform 23 for mounting the linear displacement sensor 50; and the linear displacement sensor 50 is fixed on the expansion platform 23 of the Z-axis linear displacement mechanism through a sensor mounting piece 51, and a special pressure head 60 of the displacement sensor is arranged at the head of the sensor for contact measurement. The mounting piece 51 connects the linear displacement sensor 50 with the expansion platform 23 of the Z-axis linear displacement mechanism in a three-surface wrapping mode, and the linear displacement sensor 50 is adjusted to be in a vertical position on the left side and the right side of the mounting piece 51 through tightening screws. The Z-axis linear displacement mechanism 10 can realize accurate linear displacement in the Z-axis direction.

The X-axis linear displacement mechanism 30 can realize the left-right straight movement of the displacement sensor, can detect the thickness of multiple points of the three-dimensional woven preform of the large-size revolving body deformation surface, and can calculate the height difference of different sections. The Z-axis linear displacement mechanism 10 realizes the vertical and straight movement of the displacement sensor 50, expands the measuring range of the displacement sensor and can reserve the space for the staff to operate on the machine. The X-axis linear displacement mechanism 30 and the Z-axis linear displacement mechanism 10 are both provided with the second micrometer 14, the level and the vertical of linear motion can be corrected and adjusted, the precision requirement of the measuring device is met, and the linear displacement mechanism can accurately return to the previous measuring point according to the feedback of the encoder.

Claims

1. The thickness detection device is characterized by comprising a fixed frame (1), an X-axis linear displacement mechanism (30), a Z-axis linear displacement mechanism (10), a linear displacement sensor (50), a pressure head (60), a PLC (programmable logic controller) and an upper computer;

the X-axis linear displacement mechanism (30) is arranged on the fixed frame (1) and can horizontally and linearly move along the fixed frame (1); the Z-axis linear displacement mechanism (10) is connected with the X-axis linear displacement mechanism (30) and can linearly move up and down along the X-axis linear displacement mechanism (30); the linear displacement sensor (50) is connected to the Z-axis linear displacement mechanism (10);

the lower end of the linear displacement sensor (50) is connected with a pressure head (60); the PLC is used for controlling the movement of the X-axis linear displacement mechanism (30), the Z-axis linear displacement mechanism (10) and the linear displacement sensor (50) and transmitting test data to an upper computer, the upper computer calculates the test data of the linear displacement sensor (50), and difference is obtained according to the difference between the mold measuring point and the initial position of the special pressure head and the difference between the fabric measuring point and the initial position of the special pressure head to obtain the current online thickness of the fabric (3);

the movement direction of the X-axis linear displacement mechanism (30) is parallel to the axial direction of the mould; the PLC controller controls the X-axis linear displacement mechanism (30) to compensate the distance of Rsin (theta) reversely; wherein R is the radius of the arc at the bottom of the pressure head, and the thickness of the theta fabric increases the inclination angle.

2. The thickness detection device according to claim 1, wherein the cross section of the lower end of the pressure head (60) is triangular, the bottom of the triangle is a circular arc, and the radius of the circular arc is R, so that the following conditions are satisfied:

wherein W is the concave chord length of the fabric, and epsilon is the measurement precision requirement.

3. The thickness detection device according to claim 1, wherein the X-axis linear displacement mechanism (30) comprises a first stepping motor (31), a reversing reducer (32), a first micrometer (33), a reducer mounting plate (34), a first gear (35) and a first rack (36), a first linear guide rail (37) and a first slider (38), a mounting plate (39), a first moving sliding table (40), a first stroke limiting plate (41), and a first peripheral mounting platform (42);

the mounting plate (39) is fixed on the fixing frame (1); the speed reducer mounting plate (34) is fixed on the mounting plate (39); a first sliding block (38) is fixed on the mounting plate (39); a first linear guide rail (37) and a first rack (36) are fixed on the first movable sliding table (40); the first sliding block (38) is matched with the first linear guide rail (37); the reversing speed reducer (32) and the first micrometer (33) are fixed on the speed reducer mounting plate (34), the input side of the reversing speed reducer (32) is connected with the first stepping motor (31), and the output side of the reversing speed reducer is connected with the first gear (35); the first gear (35) is meshed with the first rack (36); and both ends of the first movable sliding table (40) are provided with first stroke limiting plates (41).

4. The thickness detection device according to claim 1, wherein the Z-axis linear displacement mechanism 1 comprises a second stepping motor (11), a speed reducer (12), a commutator (13), a second micrometer (14), a mounting plate (15), a second gear (16) and a second rack (17), a second linear guide rail (18) and a second slider (19), a second stroke limiting plate (20), a second moving sliding table (21), a second external mounting platform (22), and an extension platform (23);

the mounting plate (15) is fixed on the X-axis linear displacement mechanism (30); the side surface of the commutator (13) is fixed on the mounting plate (15), the output side is connected with the second gear (16), the input side is connected with the output side of the reducer (12), the input side of the reducer (12) is connected with the second stepping motor (11), the second micrometer (14) is connected with the mounting plate (15), and the axial direction of the second micrometer (14) is consistent with the output axial direction of the reducer (12); a second sliding block (19) is fixed on the mounting plate (15); a second linear guide rail (18) is connected to the second movable sliding table (21), and the second linear guide rail (18) is matched with a second sliding block (19); and second stroke limiting plates (20) are arranged at two ends of the second movable sliding table (21).

5. The thickness detection apparatus according to claim 1, wherein the linear displacement sensor (50) is a contact resistance type displacement sensor.

6. The thickness detection apparatus according to claim 1, wherein the linear displacement sensor (50) is connected to the Z-axis linear displacement mechanism (10) through a mount.

7. The thickness detection device according to claim 6, wherein the mounting member (51) connects the linear displacement sensor (50) to the Z-axis linear displacement mechanism by three-side wrapping, and the mounting member adjusts the linear displacement sensor (50) to a vertical position by tightening screws on the left and right sides.

8. The thickness detection device according to claim 1, wherein the testing process comprises: firstly, an X-axis linear displacement mechanism is manufactured to a specified measuring point and a specified initial height to which the Z-axis linear displacement mechanism is controlled to move, and a pressure head is positioned in the horizontal tangential direction of the top point of a die (2); then controlling a linear displacement sensor (50) to start working, extending out the slide rod until a pressure head (60) is contacted with the die (2), and detecting the distance between the die (2) and the initial height of the special pressure head (60) at a measuring point;

when the thickness of the fabric (3) is measured, the process is repeated, and when the press head (60) is contacted with the fabric (3) on the mould (2), the distance of the initial height of the press head (60) when the fabric (3) is at the measuring point is detected;

and (5) calculating the difference of the distance data by the upper computer to obtain the current online thickness of the fabric (3).