CN112964399B - Electronic device wire/spring sheet contact pressure automatic tester and test method - Google Patents

Abstract

The invention designs a full-automatic tester and a full-automatic testing method for the contact pressure of metal wires/spring pieces of electronic devices, which automatically and accurately identify the positions of a plurality of metal wires/spring pieces to be tested in the visual field range of a high-definition industrial camera, transmit the position information to upper computer software, control an adjustable object carrying sliding table to accurately move to a pressure testing position, trigger a hook of a programmable digital dynamometer to move downwards to accurately align the positions of the metal wires/spring pieces, automatically hang and pick up the metal wires/spring pieces one by one, return measured data of the dynamometer to the upper computer software, and automatically calculate to obtain the pressure value of a contact point by combining with a pressure calculation algorithm. The invention realizes the automatic test function, and the single measurement time of a single metal wire/spring piece is less than 15 s; the measuring accuracy is high, the accuracy is +/-0.05 gf in the tension range, meanwhile, the maintenance and the installation are convenient, and the overload protection function is realized.

Description

Electronic device wire/spring sheet contact pressure automatic tester and test method

technical field

The invention belongs to the field of mechanical performance testing of tiny components, and particularly relates to an automatic tester and a testing method for the contact pressure of metal wires/spring sheets of electronic devices.

Background technique

In the existing electronic products, some electronic products need to use groups of tiny metal wires/spring sheets to press the metal substrate to conduct two circuits so as to transmit electrical signals. Among them, the pressing force of the metal wire/spring sheet to the metal substrate determines the contact area of the contact, and also determines the electrical conductivity and working performance of the entire electronic product. Therefore, the pressing force of the metal wire/spring sheet to the metal substrate is determined. Precision testing is particularly important.

The traditional test method is to connect electronic products in a conducting circuit, and pull the free end of the metal wire/spring sheet fixed in the form of a cantilever beam through the hook of a simple spring force measuring device to make it out of contact with the contacting metal substrate. . When the contact pressure is zero, the conduction circuit is disconnected, and the specific tension value is obtained at the moment when the current indicator light goes out. The tension value at this time is the measured pressure value.

However, the existing tensile testing methods have the following defects: using the calibrated spring test, the testing accuracy and stability are insufficient. During the measurement process, it is necessary to measure several times to obtain the average value, and the test efficiency is low. During the test, it is difficult to keep the tensile direction perpendicular to the wire/spring piece, and the test results are deviated. During the test, it is necessary to manually control the tensile force, which is prone to over-pull and damage the wire/spring; at the same time, it is difficult to control the tensile force manually to ensure that the hooked position of the tension gauge is the same every time, resulting in errors in the measurement results, and the existing Error It is difficult to ensure that the actual measured tension force and the pressure difference formed between the metal wire/spring sheet and the metal substrate are within the allowable error range.

Since the brightness of the indicator light is related to the energy of the power supply, the range of the tension value when the indicator light is off during the actual operation is relatively large. Therefore, the method of the moment when the indicator light is off is used to determine that the pressure value of the wire/spring sheet exists. error. When testing multiple metal wires/spring sheets in groups, it is necessary to manually pick, test, record and process data one by one, and form a report. The test efficiency is extremely low, which is not conducive to liberating labor.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is: in order to solve the defects existing in the prior art, the present invention designs an automatic tester and test method for the contact pressure of electronic device wire/spring sheet.

The technical scheme of the present invention is: an electronic device wire/spring sheet contact pressure automatic tester, including a PC, an adjustable loading slide, an adjustment mechanism, a wire/spring sheet hanging measuring point determination mechanism and an experimental monitoring mechanism;

The to-be-tested piece can be moved under the action of the adjustment mechanism through the adjustable slide table, and moved to a designated position;

The piece to be tested is provided with a wire/spring piece, wherein the middle of the wire/spring piece is in contact with the piece to be tested to form a pressure bearing point, and one end is provided with a hook segment lifted by a programmable digital dynamometer;

The wire/spring piece hanging measuring point determination mechanism includes a photographing device and a lighting device. After the test piece is located directly under the photographing device, the lighting device illuminates the wire/spring piece to form a light reflection point, and the brightest spot captured by the photographing device is The position is the initial position of the light reflection point on the wire/spring sheet, and after coordinate transformation, the best hanging measurement point of the wire/spring sheet is obtained; the hook segment of the wire/spring sheet and the adjacent wire/spring segment are separated. The angle between them is α, and the angle between the lighting lamp and the horizontal plane is π-α;

The experimental monitoring mechanism includes a control system, a dynamometer, a third slide rail assembly, a first camera and a second camera. The control system is provided with a third slide rail assembly, and the dynamometer can be driven by the third slide rail assembly. Move back and forth in the Z direction; when the wire/spring piece determines the best hanging point, move the dynamometer just below the hook with the cooperation of the three slide rail assemblies, and then start the test; the dynamometer is used to connect the wire / The spring sheet is pulled up and the tension value during the measurement process is displayed in real time and the data is transmitted to the PC. The PC automatically calculates the contact point pressure value; the first camera and the second camera are on the wire/spring sheet lifting process state Real-time camera monitoring.

The further technical scheme of the present invention is: it also includes a box body and a vibration isolation table, wherein the adjustment mechanism, the wire/spring piece hanging measuring point determination mechanism and the experimental monitoring mechanism are located in the box body, and the box body and the PC are located on the vibration isolation table.

A further technical solution of the present invention is that: the test piece is fixed on the adjustable slide table, and the test piece is provided with a metal wire/spring piece and a metal substrate; the metal wire/spring piece is divided into straight sections, The wave section and the hook section, the straight section is fixedly connected with the metal substrate, the wave trough of the wave section is in contact with the test piece to form a pressure bearing point, and the hook section is the lifting part of the programmable digital dynamometer.

A further technical solution of the present invention is: the wire/spring piece hanging measuring point determination mechanism further includes an observation plate, the observation plate is provided with a through hole as a light hole, and the axis of the light hole coincides with the axis of the lens of the photographing device ; There is a lighting lamp under the observation board; the photographing device and the observation board are connected to the inner side wall of the box by a cantilever beam; the angle between the wave segment and the hook segment is defined as α, and the angle between the lighting device and the horizontal plane is π- α; After the test piece is moved under the photographing device through the adjusting mechanism, a light reflection point is formed on the wire/spring sheet by illuminating the lighting device, and the position of the brightest spot captured by the photographing device is the initial point of the light reflection point on the wire/spring sheet. position, and after coordinate transformation, the best hanging measuring point of the wire/spring piece is obtained.

A further technical solution of the present invention is: the adjusting mechanism is located at the bottom of the box, and includes a first slide rail assembly and a second slide rail assembly, wherein the first slide rail assembly is located at the bottom of the box, and the second slide rail assembly is located at the first slide rail assembly. The top is crossed, and the installation direction of the slide rail in the first slide rail assembly is defined as the X direction, the installation direction of the slide rail in the second slide rail assembly is the Y direction, and the direction perpendicular to both X and Y is the Z direction.

A further technical solution of the present invention is that: the adjustable object slide table is located on the second slide rail assembly, the adjustable object slide table can move in the Y direction through the second slide rail assembly, and the first slide rail assembly can drive the second slide rail assembly. The second slide rail assembly moves in the X direction.

A further technical solution of the present invention is that: the first slide rail assembly, the second slide rail assembly and the third slide rail assembly all include a slide rail and a motor, and the motor converts rotational motion into linear motion through a screw rod.

A further technical solution of the present invention is that: the axes of the lenses of the first camera and the second camera are vertically distributed.

A further technical solution of the present invention is: a test method for an electronic device wire/spring sheet contact pressure automatic tester, characterized in that it includes the following steps:

Step 1: Place the test piece on the adjustable slide table through the positioning fixture. The height of the test piece in the box is the height of the positioning fixture plus the height of the test piece itself, and the height of the positioning fixture is the initial given value. value, the position of the box is fixed; the spatial coordinate value of the high-definition industrial camera is the initial setting value;

Step 2: Determine the initial position of the test piece, including the following sub-steps:

Sub-step 2.1: Move the object to be tested under the lens of the high-definition industrial camera through the first slide rail assembly and the second slide rail assembly. The illumination lamp provides light, and the parallel light source is reflected by the light reflection point on the wire/spring sheet, and will be vertical. Enter the high-definition industrial camera through the light hole, and the high-definition industrial camera takes pictures to obtain photos, and captures the brightest position on each wire/spring sheet, which is the initial position of the light reflection point on the wire/spring sheet;

Sub-step 2.2: Convert the position of the brightest point in the previous step in the photo coordinate system to the position in the box coordinate system to obtain the initial position of the brightest point;

Step 3: Controlled by the PC, drive the test piece to move through the first slide rail assembly and the second slide rail assembly, and move the wire/spring sheet to the vicinity of the hook of the digital dynamometer;

Step 4: Fine tune the piece to be tested so that the hook of the programmable digital dynamometer is directly below one of the wire/spring leaf hook segments:

Step 5: Set the limit value of tension and pressure of the programmable digital dynamometer in the PC, and the limit value is lower than the peak value that can be measured by the programmable digital dynamometer;

Step 6: Start the experiment and analyze, including the following steps:

Sub-step 6.1: Drive the programmable digital dynamometer to move in the Z direction along the slide rail through the third slide rail assembly, so that the hook contacts the wire/spring sheet, and hooks the best hanging measuring point on the wire/spring sheet, pull up evenly

Sub-step 6.2: In the process of pulling up at a constant speed, program a digital dynamometer to obtain multiple sets of tension displacement data, and obtain multiple tension-displacement points in the tension-displacement coordinate system through the multiple sets of tension-displacement data;

Sub-step 6.3: Perform real-time calculation on the point obtained in step 6.2. The calculation process is that each time a new point A ₂ is generated, the calculation is made up of the point and the previous point A ₁ (the point when the programmable digital dynamometer begins to show readings). The slope of the line segment is recorded as the slope K ₁ , then calculate the slope K ₂ of the line segment formed by the newly generated points A ₃ and A ₂ , and compare the slope difference between K ₁ and K _2. If the difference is less than 10%, it is regarded as the slope No mutation, repeat the process, calculate the slope K _i of the line segment composed of the newly generated points A _i+1 and A _i , and calculate the slope K i+1 of the line segment composed of the newly generated points A _i+2 and A _{i +1} , compare the slope difference between _Ki and Ki ₊₁ , until the slope difference between a certain point and the previous point and the latter point is greater than 10%, mark the point as B, and determine that the slope changes abruptly at point B.

Step 7: Perform steps 3 to 6 for other wires/springs. After all wire/spring tests are completed, separate the hook of the programmable digital dynamometer from the wire/spring.

A further technical solution of the present invention is that: the ratio of the slope difference refers to the ratio of the slope difference to the slope of a straight line segment with a smaller slope in a group of adjacent straight line segments.

Invention effect

The technical effect of the present invention is as follows: the present invention provides an automatic tester and a testing method for the contact pressure of electronic device wires/spring sheets, which can automatically and accurately identify the positions of a plurality of wires/spring sheets to be tested within the field of view of a high-definition industrial camera, and automatically and accurately identify the positions of multiple wires/spring sheets to be tested. The position information is transmitted to the host computer software to control the adjustable load slide to move to the pressure test position accurately, and then trigger the hook of the programmable digital dynamometer to move down to accurately align the wire/spring piece position, and automatically hook up one by one. Metal wire/spring piece, the measured data of the dynamometer is returned to the host computer software, combined with the pressure calculation algorithm, the contact point pressure value is automatically calculated, and the specific invention effects include the following aspects:

(1) The present invention has the automatic testing function of the contact pressure of multiple groups of metal wires/spring sheets, and has the function of data display and data storage at the same time. Data is exported to the PC-side function. The programmable digital dynamometer can quickly and accurately measure the tiny pressure value of the metal wire/spring piece of tiny components, and the single measurement time of a single metal wire/spring piece is less than 15s.

(2) The present invention obtains the position information of the tiny component wire/spring sheet through a high-definition industrial camera, and the first camera and the second camera monitor the state of the process of lifting the wire/spring sheet by the hook of the programmable digital dynamometer in real time. , Through the slide rails in the first slide rail assembly and the slide rails in the second slide rail assembly, precise motion control is performed on the adjustable carrier slide, and then automatic position movement control is performed on the tiny components, which is easy to operate and has One-button automatic measurement and move function.

(3) The present invention has the functions of emergency stop and overload protection. The measurement software in the PC is parameterized to set the limit value of the measurable tension and pressure of the programmable digital force gauge, which is higher than that of the programmable digital force gauge. The measurable peak value of the gauge is low, preventing the programmable digital force gauge 9 from overloading and stopping operation in time.

(4) The measurement accuracy of the present invention is high, and the accuracy within the tension range is ±0.05gf;

(5) The present invention has high reliability, and the measurement error rate is lower than 5%;

(6) The device in the present invention is easy to disassemble and disassemble, and it is easy to disassemble and replace individual parts or electronic components during maintenance and inspection.

(7) The present invention has a wide range of applications, and can also be applied to bonding process testing of integrated circuits and semiconductor chips.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Fig. 2 is the partial enlarged schematic diagram of the test piece part of the present invention;

3 is an enlarged schematic diagram of an initial position positioning part according to an embodiment of the present invention;

4 is a partially enlarged schematic diagram of the state of the real-time camera monitoring part of the process of lifting the wire/spring sheet to the precision force measuring hook according to the embodiment of the present invention;

Figure 5 is a schematic diagram of the structure of the programmable digital dynamometer control box after removing the shell

Figure 6 is the "force-displacement" curve obtained by the real-time pressure value data obtained by the data acquisition software; the curve AB stage is the stage when the spring wire is lifted up and does not leave the contact with the metal substrate; the curve BC stage is the spring wire is hooked up The stage of rising and coming out of contact with the metal substrate.

Description of reference numerals: 1-box body; 2-high-definition industrial camera; 3-lighting lamp; 4-specimen; 5-positioning fixture; 6-adjustable slide table; 7-X-direction slide rail; ;9-Programmable digital force gauge;10-First camera; 11-Second camera; 12-PC machine; 13-Vibration isolation table; 14-Light reflection point on wire/spring sheet; 15-Light hole ; 16-Y-direction slide rail; 17-programmable digital dynamometer control box; 18-Z-direction slide rail; 19-wire/spring piece and hook contact point; 20-observation board.

Detailed ways

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " rear, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc., or The positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation of the present invention.

Referring to FIG. 1-FIG. 6, an embodiment of the present invention provides a contact-type brush pressure automatic tester for electronic devices, and the specific components included are: a box body, a high-definition industrial camera, a first camera, a second camera, a positioning fixture, a Loading slide table, slide rail, motor, programmable digital dynamometer, programmable digital dynamometer control box, PC and vibration isolation table, lighting and observation board.

The working principle of the invention is to automatically and accurately identify the positions of multiple wires/spring sheets to be tested within the field of view of the high-definition industrial camera, and transmit the position information to the upper computer software of the PC to control the automatic stage to move to the pressure test position accurately. After that, trigger the precision hook to move down to accurately align the position of the wire/spring piece, automatically pick up the wire/spring piece one by one, and the measured data of the programmable digital dynamometer is returned to the host computer software, and combined with the pressure calculation algorithm, it is automatically calculated. Contact point pressure value function, and automatically generate reports.

The high-definition industrial camera, lighting and observation board form the part to obtain the initial position of the wire/spring piece relative to the box coordinate system; the specimen, positioning fixture, adjustable carrier slide, slide rail and motor form the precise movement of the wire/spring piece The control part; the programmable digital dynamometer, the first camera, the second camera, and the PC load test piece constitute the data measurement and analysis part of the wire/spring sheet in the pressure test.

The programmable digital dynamometer is used to display the tensile force value in the measurement process in real time and export the data to the PC. The PC is equipped with supporting upper analysis software to analyze the data and the movement of the test piece. Take control.

The high-definition industrial camera is connected to the rear wall of the box through a cantilever beam. Below the high-definition industrial camera is a light-penetrating hole plate connected to the rear wall of the box. Below, the board is connected to the illuminator through connecting corner pieces, as shown in Figure 3. When determining the initial position of each wire/spring sheet, the test piece is fixed by the positioning fixture, which is located just below the light-passing hole, and this position is also set as the "0" position of the entire control system.

In the wire/spring leaf precise motion control part, the slide rail in the first slide rail assembly is defined as the X-direction slide rail, and the slide rail in the second slide rail assembly is defined as the Y-direction slide rail. The X-direction slide rail is connected to the bottom plate of the box body, and the slide table on the X-direction slide rail is connected to the Y-direction slide rail by screws. The adjustable loading slide is placed on the Y-direction guide rail, and a positioning fixture is installed on the adjustable loading slide, and the positioning fixture fixes the test piece by its own clamping force. A motor is installed at the rear end of the slide rail to provide power, and the motor converts the rotary motion into linear motion through the screw. The X-direction slide rail drives the adjustable object slide table to move in the X-direction for a long distance, and the adjustable object slide table uses the Y-direction slide rail to perform fine-tuning in the Y direction and alignment of the photographic positioning "0".

In the data measurement and analysis part of the wire/spring piece in the pressure test, the programmable digital dynamometer, the first camera and the second camera are connected to the programmable digital dynamometer control box, and the programmable digital dynamometer The control box is connected to the rear wall of the box, the first camera and the second camera are placed under the programmable digital force gauge, and the first camera and the second camera are vertically distributed, as shown in Figure 4. There is a third slide rail assembly in the programmable digital dynamometer control box, and the slide rail in this slide rail assembly is defined as a Z-direction slide rail, and a motor that provides power is connected behind the Z-direction slide rail. For Z-direction motion control, a motor that provides power is connected behind the Z-direction slide rail, as shown in Figure 5. During the test, the DUT moves with the adjustable load slide directly below the programmable digital force gauge.

The high-definition industrial camera measures the initial position of the wire/spring, where the lighting lamp provides a parallel light source, and the installation angle of the lighting is related to the structure of the wire/spring, as shown in Figure 2, when the rear end of the wire/spring When the angle is α, the angle between the lighting lamp and the horizontal plane is π-α. When the parallel light source shines on the key feature points of the wire/spring, the light passes through the light hole vertically upward, and the high-definition industrial camera will capture the brightest point, and the position of the brightest point is the light reflection point on the wire/spring. The initial position, and then the position of the wire/spring sheet on the specimen that needs to be hung; it should be noted that this position is close enough to the contact point between the wire/spring sheet and the metal substrate, and the hook can reach the contact point. The pull value measured by hooking up the wire/spring sheet here can more accurately express the pressure value between the wire/spring sheet and the metal substrate.

The first camera and the second camera perform real-time camera monitoring on the process and state of the hook of the programmable digital dynamometer hooking up the wire/spring piece. As shown in Figure 6, in the process of pulling up the wire/spring sheet at a constant speed, it is divided into the stages before the wire/spring sheet and the metal substrate come out of contact, namely curve A ₁ B stage and the wire/spring sheet is separated from the metal substrate After contact, the curve BC stage two stages. In the stage when the wire/spring piece is lifted up and not out of contact with the metal substrate, the distance used for the wire/spring piece to rise and lift is very small, the tensile force count value increases rapidly at this stage, and the programmable digital dynamometer obtains A series of force-displacement numerical points, and these obtained points are calculated in real time. The calculation process is that each time a new point A ₂ is generated, the calculation of this point and the previous point _A ), denoted as the slope K ₁ , then calculate the slope K ₂ of the line segment formed by the newly generated points A ₃ and A ₂ , compare the slope difference between K ₁ and K ₂ , if the difference is less than 10%, then It is determined that the slope has not changed abruptly, repeat the process, calculate the slope K _i of the line segment formed by the newly generated points A _i+1 and A _i , and calculate the slope K of the line segment formed by the newly generated points A _i+2 and A _{i+1 i+1} , compare the slope difference between K _i and K _i+1 , until the slope difference between a certain point and the previous point and the latter point is greater than 10%, mark this point as B, and determine that the slope changes abruptly at point B. In the stage where the wire/spring piece is lifted up and out of contact with the metal substrate, this stage is the stage after the inflection point appears (the slope has changed abruptly). After the extension of about 20 μm, the formation was stopped, and the final obtained point was marked as point C, as shown in Fig. 6 .

The inflection point B is the point at which the slope changes abruptly, and the tensile force reading at this point is the tensile force value required at the moment when the wire/spring piece is separated from the metal substrate, which is determined by the present invention when the wire/spring piece is out of contact with the metal substrate. Pressure value.

The test method based on the above device includes the following steps:

Step 1: Clamping and positioning of the specimen: place the specimen to be tested horizontally in the positioning fixture 5 on the adjustable carrier slide 6, and fix it by the clamping force of the positioning fixture 5 itself. The coordinates are the Z coordinate of the positioning fixture 5 plus the height value of the specimen itself. The Z coordinate of the positioning fixture 5 has been measured at the beginning of the layout design of the invention and is a fixed value in the box.

Step 2: Determine the initial position of the test piece: move the test piece to the range below the lens of the high-definition industrial camera 2 through the X-direction slide rail 7 and the Y-direction slide rail 16, the illumination lamp 3 provides light, and the parallel light source passes through the light on the wire/spring sheet. The reflection from the reflection point 14 will enter the high-definition industrial camera 2 vertically through the light hole 15. The high-definition industrial camera 2 will capture the brightest point position on each wire/spring sheet, which is the spot on the wire/spring sheet. The initial position of the light reflection point 14, the spatial coordinates of the high-definition industrial camera 2 have been measured before the test, it is a certain value in the box, and the direction of the high-definition industrial camera 2 is vertically downward, the coordinate range of the photographed photo is fixed, the The initial position of the point to be measured is obtained by converting the position of the point to be measured in the photo coordinate system into the XY coordinates in the entire box 1 .

Step 3: Move the test piece to the lower end of the digital dynamometer: The PC 12 automatically analyzes the relative position of the programmable digital dynamometer 9 according to the initial position information of all the points to be measured. The programmable digital dynamometer 9. The spatial coordinates have been measured before the test, and are a certain value in the box; input the parameters into the control software, and adjust the position of the specimen in the 4X-Y direction through the X-direction slide rail 7 and the Y-direction slide rail 16, so that the wire / The spring piece is placed near the hook of the programmable digital force gauge 9, that is, the difference between the X-Y coordinates of the two is within 10mm.

Step 4: Fine-tune the three directions of X-Y-Z in the coordinate system of the test piece itself, so that the hook is placed directly under the wire/spring piece: According to the new position coordinates obtained in the previous step, the X-Y direction of the test piece itself in the coordinate system The position is fine-tuned so that the contact point 19 between the wire/spring piece and the hook is 5mm away from the X direction of the hook of the programmable digital force gauge 9, and the Y direction is flush; then the programmable digital force gauge 9 is aligned with the Z direction slide rail 18. Perform Z-direction movement so that the hook is slightly lower than the contact point 19 of the wire/spring sheet and the hook, that is, the hook is about 32 μm below the contact point 19, and the specimen 4 is fed through the X-direction slide rail 7, so that the metal The wire/spring piece is passed through the hook, i.e. the hook is placed directly under the wire/spring piece.

Step 5: Set the limit value of the tensile and compressive force of the measuring software on the PC: set the parameters of the measuring software in the PC 12, and set the measurable limit value of the tensile and compressive force of the programmable digital force gauge 9, which is higher than the programmable limit value. The measurable peak value of the digital dynamometer 9 is low, which prevents the programmable digital dynamometer 9 from being overloaded and stops running in time.

Step 6: Hook up the wire/spring and start the test: Make the programmable digital dynamometer 9 rise slowly and uniformly through the Z-direction slide rail 18, so that the hook contacts the wire/spring, and connect the wire/spring When hooked up, the programmable digital dynamometer 9 will perform real-time tensile force measurement to obtain several force-displacement points, and at the same time, the force begins to change with the displacement of the programmable digital dynamometer 9, as shown in FIG. 6 .

Step 7: Perform real-time calculation on the points obtained in Step 6. The calculation process is to calculate the line segment formed by this point and the previous point A ₁ (the point when the programmable digital dynamometer starts to read) for each new point A ₂ generated. The slope of , denoted as slope K ₁ , then calculate the slope K ₂ of the line segment formed by the newly generated points A ₃ and A ₂ , compare the slope difference between K ₁ and K ₂ , if the difference is less than 10%, it is considered that the slope is not Mutation, repeat the process, calculate the slope K _i of the line segment composed of the newly generated points A _i+1 and A _i , calculate the slope K i+1 of the line segment composed of the newly generated points A _i+2 and A _{i +1} , Compare the slope difference of K _i and K _i+1 until the slope difference between a certain point and the previous point and the next point is greater than 10%, mark the point as B, and determine that the slope changes abruptly at point B.

Through real-time calculation of the points obtained by the programmable digital dynamometer, and continuous comparison of the slope difference, the point where the slope difference is greater than 10% is finally obtained, that is, the slope mutation point B, and the tensile force reading at this point is The tensile force value required at the moment when the metal wire/spring sheet is separated from the metal substrate is the pressure value determined by the present invention when the metal wire/spring sheet is separated from the metal substrate.

Step 8: Return to the origin: After all the wires/spring pieces are hung up in sequence, the programmable digital dynamometer 9 slowly descends with the Z-direction slide rail 18, so that the hooks are separated from the wire/spring pieces, and then the test piece 4 follows the The X-direction slide rail 7 is withdrawn from the top of the hook and returns to the initial position "0".

Claims (9)

1. The full-automatic tester for the contact pressure of the metal wire/spring piece of the electronic device is characterized by comprising a PC (personal computer), an adjustable carrying sliding table, an adjusting mechanism, a metal wire/spring piece hanging and measuring point determining mechanism and an experiment monitoring mechanism;

The piece to be tested can move under the action of the adjusting mechanism through the adjustable loading sliding table and move to an appointed position;

the testing device comprises a testing part, a testing part and a hook part, wherein the testing part is provided with a metal wire/spring piece and a metal substrate, the metal wire/spring piece is divided into a straight line section, a wave section and a hook section, the straight line section is fixedly connected with the metal substrate, the wave trough of the wave section is in contact with the testing part to form a pressure stress point, and the hook section is a lifting part of a programmable digital dynamometer;

wherein the middle part of the metal wire/spring piece is contacted with a to-be-tested piece to form a pressure stress point, and one end of the metal wire/spring piece is provided with a hook section lifted by the programmable digital dynamometer;

the metal wire/spring piece hanging point determining mechanism comprises a shooting device and an illuminating device, after a to-be-tested piece is positioned under the shooting device, the illuminating device irradiates the metal wire/spring piece to form a light reflection point, the position of the brightest point captured by the shooting device is the initial position of the light reflection point on the metal wire/spring piece, and the optimal hanging point of the metal wire/spring piece is obtained after coordinate conversion; wherein the included angle between the metal wire/spring piece hook section and the adjacent metal wire/spring piece is alpha, and the included angle between the illuminating lamp and the horizontal plane is pi-alpha;

the experiment monitoring mechanism comprises a control system, a dynamometer, a third slide rail assembly, a first camera and a second camera, wherein the third slide rail assembly is arranged on the control system, and the dynamometer can move back and forth along the Z direction under the driving of the third slide rail assembly; after the metal wire/spring piece determines the optimal hanging measuring point, moving the part right below a hook of the dynamometer under the matching of the three slide rail assemblies, and then starting to perform a test; the dynamometer is used for pulling up the metal wire/spring piece, displaying the tension value in the measuring process in real time and transmitting data to the PC, and the PC automatically calculates to obtain the contact point pressure value; the first camera and the second camera carry out real-time camera monitoring on the state of the lifting process of the metal wire/spring piece.

2. The full-automatic tester for contact pressure of the metal wire/spring plate of the electronic device as claimed in claim 1, further comprising a box body and a vibration isolation table, wherein the adjusting mechanism, the metal wire/spring plate hanging point determining mechanism and the experiment monitoring mechanism are located in the box body, and the box body and the PC are located on the vibration isolation table.

3. The full-automatic tester for contact pressure of the metal wire/spring plate of the electronic device as claimed in claim 1, wherein the metal wire/spring plate hanging point determining mechanism further comprises an observation plate, a through hole is formed on the observation plate as a light through hole, and the axis of the light through hole is coincident with the axis of a lens of a shooting device; an illuminating lamp is arranged below the observation plate; the shooting device and the observation plate are connected to the inner side wall of the box body in a cantilever beam mode; defining an included angle between the wave section and the hook section as alpha, and defining an included angle between the illuminating device and the horizontal plane as pi-alpha; after the piece to be tested moves to the position below the shooting device through the adjusting mechanism, the lighting device irradiates the metal wire/spring piece to form a light reflection point, the position of the brightest point captured by the shooting device is the initial position of the light reflection point on the metal wire/spring piece, and the optimal hanging point of the metal wire/spring piece is obtained after coordinate conversion.

4. The fully automatic tester for contact pressure between a wire/spring plate of an electronic device as claimed in claim 1, wherein the adjusting mechanism is located at the bottom of the case and comprises a first rail assembly and a second rail assembly, wherein the first rail assembly is located at the bottom of the case, the second rail assembly is located above the first rail assembly and distributed in a cross shape, the mounting direction of the rail in the first rail assembly is defined as X direction, the mounting direction of the rail in the second rail assembly is defined as Y direction, and the direction perpendicular to both X, Y is defined as Z direction.

5. The fully automatic tester for contact pressure between a wire/leaf spring of an electronic device according to claim 4, wherein the adjustable object slide is disposed on the second rail assembly, the adjustable object slide is capable of moving in the Y direction via the second rail assembly, and the first rail assembly is capable of driving the second rail assembly to move in the X direction.

6. The fully automatic tester for contact pressure of an electronic device wire/spring plate of claim 4 wherein the first, second and third slide assemblies each comprise a slide and a motor that converts rotational motion to linear motion via a screw.

7. The fully automatic tester of contact pressure of an electronic device wire/leaf spring of claim 1 wherein the first camera and the second camera have lens axes that are vertically spaced.

8. The method for testing the full-automatic tester for the contact pressure of the metal wire/spring piece of the electronic device according to claim 1, comprising the following steps:

step 1: placing a to-be-tested test piece on the adjustable carrying sliding table through a positioning fixture, wherein the height of the test piece in the box body is the sum of the height of the positioning fixture and the height value of the test piece, the height of the positioning fixture is an initial given value, and the position of the box body is fixed; the space coordinate value of the high-definition industrial camera is an initial set value;

step 2: determining an initial position of a piece to be tested, comprising the following sub-steps:

substep 2.1: the method comprises the following steps that a to-be-tested piece is moved to the position below a lens of a high-definition industrial camera through a first sliding rail assembly and a second sliding rail assembly, an illuminating lamp provides illumination, a parallel light source is reflected by a light reflection point on a metal wire/spring piece and vertically enters the high-definition industrial camera through a light through hole, the high-definition industrial camera takes a picture to obtain a picture, and the brightest position on each metal wire/spring piece is captured, namely the initial position of the light reflection point on the metal wire/spring piece;

substep 2.2: converting the position of the brightest point in the photo coordinate system in the last step into the position in the box coordinate system to obtain the initial position of the brightest point;

And 3, step 3: under the control of a PC (personal computer), a piece to be tested is driven to move by a first slide rail assembly and a second slide rail assembly, and the metal wire/spring piece is moved to the position near a hook of the digital dynamometer;

and 4, step 4: and finely adjusting the piece to be tested to enable a hook of the programmable digital dynamometer to be positioned right below one of the metal wire/spring piece hook sections:

and 5: setting a pulling pressure limit value of the programmable digital dynamometer in the PC machine, wherein the limit value is lower than a peak value measurable by the programmable digital dynamometer;

step 6: the test was started and analyzed, comprising the following steps:

substep 6.1: the programmable digital dynamometer is driven to move in the Z direction along the slide rail through the third slide rail component, so that the hook is in contact with the metal wire/spring piece and hooks the optimal hanging measuring point on the metal wire/spring piece, and the hook is pulled up at a constant speed;

substep 6.2: in the process of uniform-speed pulling, programming a digital dynamometer to obtain a plurality of groups of tension displacement data, and obtaining a plurality of tension-displacement points under a tension-displacement coordinate system through the plurality of groups of tension displacement data;

substep 6.3: the points obtained in step 6.2 are calculated in real time, and a new point A is generated every time in the calculation process ₂ Calculate the point and the previous point A ₁ The slope of the line segment formed, where A ₁ For starting to appear on programmable digital ergometersThe point at which the reading took place is noted as the slope K ₁ Subsequently, the newly generated point A is calculated ₃ And A ₂ Slope K of the line segment ₂ Comparison K ₁ And K ₂ If the difference is less than 10%, the slope is determined not to be mutated, the process is repeated, and a newly generated point A is calculated _i+1 And A _i Slope K of the line segment _i Calculating the newly generated point A _i+2 And A _i+1 Slope K of the line segment _i+1 Comparison K _i And K _i+1 Until the difference between the slope of a certain point and the slope of the previous point and the slope of the next point is more than 10%, marking the point as B, and determining that the slope is mutated at the point B;

and 7: and (5) carrying out the operations of the steps (3) to (6) on other metal wires/spring pieces, and separating the hook of the programmable digital dynamometer from the metal wires/spring pieces after all the metal wires/spring pieces are tested.

9. The method of claim 8 for testing the fully automatic tester of contact pressure of the electronic device wire/spring plate comprises: and the ratio of the slope difference to the slope of one straight line segment with smaller slope in a group of adjacent straight line segments is the slope difference ratio.

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