A speed measuring device for deformed workpieces in high-speed forming and its application

Abstract

The present invention belongs to the field of digital measurement technology, and specifically discloses a speed measurement device for a deformed workpiece in high-speed forming and its application. The device includes a striker module, a power supply and signal conversion module, and a data acquisition module that are electrically connected in sequence. The striker module includes a first circuit board and at least two striker units. The striker units are all vertically arranged on the first circuit board, and the height difference h between adjacent striker units can be adjusted. During operation, the workpiece to be measured can collide with the striker units of different heights in turn. During the collision process, the workpiece to be measured generates a collision electric signal in the first circuit board, and the collision electric signal is transmitted to the power supply and signal conversion module; the power supply and signal conversion module converts the collision electric signal into a voltage signal and then transmits it to the data acquisition module; the data acquisition module fits a voltage waveform diagram and obtains the successive collision times of the workpiece to be measured, and then calculates the movement speed of the workpiece to be measured based on the time and height difference h.

Description

Technical Field

[0001] The present invention belongs to the field of digital measurement technology, and more particularly, relates to a speed measurement device for a deformed workpiece in high-speed forming and an application thereof. Background Art

[0002] High-speed forming technology is a method of plastic processing and forming materials by using the instantaneous impact force generated by the instantaneous release of energy, such as electromagnetic forming, electro-hydraulic forming and explosive forming. High-speed forming can significantly improve the forming limit of materials. This is because the instantaneous impact force acts on the workpiece, causing the workpiece to deform at a speed of tens to hundreds of meters per second and a strain rate of 10 2 ~10 4 / s. The inertial effect brought by high speed can improve the stress distribution within the material and suppress local necking. In order to more accurately analyze the high-speed deformation process, it is necessary to accurately obtain the speed changes and distribution of the deformed workpiece during the forming process. During high-speed deformation, the movable range of the deformed workpiece is generally millimeters to hundreds of millimeters, and the deformation time is only microseconds to milliseconds. However, the shape and size of the deformed workpiece vary even more, which makes it difficult to measure the speed of any point on the workpiece.

[0003] Currently, the methods for obtaining the motion-related values ​​of a workpiece and its numerical distribution mainly include non-contact measurement methods and contact measurement methods:

[0004] Non-contact measurement methods usually use non-contact instruments such as laser displacement sensors, laser Doppler velocimeters and high-speed cameras for measurement. Their disadvantages are that the experimental environment requirements are strict and it is difficult to apply to electromagnetic forming conditions. After measurement, complex data processing is required to obtain the speed of the object's movement. For example, patent CN108051123A discloses a dynamic measurement system for a transient impact force impact process and its implementation method. A high-speed laser displacement sensor is used to obtain the displacement of the moving part during the movement process to improve the dynamic measurement accuracy of the transient impact process. However, in the electromagnetic forming environment, the deformed workpiece is usually placed inside the electromagnetic driver, and the movement space of the workpiece to be measured is narrow and the light is insufficient. This makes it difficult for the laser sensor to measure the displacement of the workpiece movement, and thus it is difficult to obtain the movement speed of the workpiece.

[0005] Existing contact measurement methods use capacitive sensors, among others. Capacitive sensors work by contacting the workpiece with the capacitor plates, causing the plates to move, thereby changing the capacitor's capacitance. By measuring the capacitance of the capacitor, the workpiece's velocity can be determined. However, during electromagnetic forming, the workpiece typically moves at speeds of several hundred meters per second. The resulting impact force with the capacitor plates is significant, easily damaging capacitive sensors and making them difficult to use in electromagnetic forming environments. Summary of the Invention

[0006] In view of the defects of the prior art, the purpose of the present invention is to provide a speed measurement device for a deformed workpiece in high-speed forming and its application, so as to solve the problem that the existing measuring devices and methods are difficult to measure the instantaneous speed of the deformed workpiece in the electromagnetic high-speed forming environment.

[0007] To achieve the above object, the present invention provides a speed measurement device for a deformed workpiece during high-speed forming, comprising a striker module, an energy supply and signal conversion module, and a data acquisition module electrically connected in sequence, wherein:

[0008] The striker module includes a first circuit board and at least two striker units, each of which is vertically arranged on the first circuit board. The height of each striker unit is different, and the height difference h between adjacent striker units can be adjusted based on measurement conditions. During operation, the workpiece to be measured can collide with the striker units of different heights in sequence. During the collision process, the workpiece to be measured generates a collision electrical signal in the first circuit board, and the first circuit board transmits the collision electrical signal to the energy supply and signal conversion module.

[0009] The energy supply and signal conversion module is used to provide electrical energy to the striker module and convert the received collision electrical signal into a voltage signal and transmit it to the data acquisition module;

[0010] The data acquisition module is used to fit a voltage waveform based on the voltage signal, and obtain the time when the workpiece to be measured collides with each of the striker units based on the voltage waveform, and then calculate the movement speed of the workpiece to be measured based on the time and the height difference h.

[0011] Furthermore, the power supply and signal conversion module includes a second circuit board, a second wire-to-board connector is provided on the second circuit board, a first wire-to-board connector is provided on the first circuit board, and the first wire-to-board connector is electrically connected to the second wire-to-board connector to electrically connect the first circuit board and the second circuit board.

[0012] Furthermore, a linear voltage-regulated power supply and a resistance voltage divider circuit are also provided on the second circuit board, and the second circuit board is electrically connected to the data acquisition module; the linear voltage-regulated power supply is used to provide a constant voltage to the striker module via the second wire-to-board connector; the resistance voltage divider circuit is used to output the voltage signal to the data acquisition module based on the collision electrical signal according to a preset voltage divider ratio.

[0013] Furthermore, each of the striker units includes two strikers, and all the strikers are vertically fixed on the first circuit board, the two strikers have the same height, and adjacent strikers are insulated from each other; preferably, all the strikers are arranged in rows at equal distances.

[0014] Furthermore, the collision ends of all the striker units have the same shape; preferably, the collision ends of the striker units are flat heads or pointed cone heads.

[0015] Furthermore, the first wire-to-board connector includes the same number of connection units as the striker units, and the second wire-to-board connector includes the same number of connection units as the striker units, wherein the connection units on the first wire-to-board connector are respectively connected one-to-one with the connection units on the striker units and the second wire-to-board connector.

[0016] Furthermore, the second wire-to-board connector further includes a transmission connection unit electrically connected to the data acquisition module, and the transmission connection unit is used to output the collision electrical signal to the data acquisition module.

[0017] According to another aspect of the present invention, there is also provided an application of a speed measurement device as described above, the application steps comprising:

[0018] S1. Determine the displacement height H of the workpiece to be measured at a specific moment based on the theoretical speed-time curve and displacement-time curve of the workpiece to be measured;

[0019] S2, placing the workpiece to be measured above the striker unit at a distance H, and adjusting the height difference h between adjacent short striker units to be less than 5% H;

[0020] S3, moving the workpiece to be measured up and down at high speed, and first colliding with the longer striker unit and then with the shorter striker unit, so that the workpiece to be measured is electrically connected to the measuring device, and generating a collision electrical signal in the first circuit board during the continuous collision process;

[0021] S4, the energy supply and signal conversion module receives the collision electrical signal transmitted by the first circuit board, and converts the collision electrical signal into a voltage signal and transmits it to the data acquisition module;

[0022] S5, the data acquisition module generates a voltage waveform diagram based on the voltage signal, and obtains the occurrence time t1 of the striker unit with a higher collision and the occurrence time t2 of the striker unit with a lower collision based on the voltage waveform diagram to calculate the movement speed v of the workpiece to be measured;

[0023] S6. Repeat steps S1-S5 multiple times to obtain multiple movement speeds, and calculate an average value of the multiple movement speeds. The average value is the actual movement speed of the workpiece to be measured.

[0024] Furthermore, in step S2, the height difference h also satisfies the following relationship:

[0025]

[0026] Among them, v1 is the theoretical instantaneous velocity of the workpiece to be measured at a specific moment, and f is the sampling rate of the data acquisition module.

[0027] Furthermore, in step S6, before each measurement, the relative position between the workpiece to be measured and the striker module is adjusted so that the position where the workpiece to be measured collides with the striker unit is different from the position where the previous collision occurred, so as to obtain the velocity value at any position on the workpiece to be measured.

[0028] The above technical solution conceived by the present invention has the following advantages compared with the prior art:

[0029] 1. The present invention provides a contact speed measuring device suitable for a high-speed forming electromagnetic environment. In the device, the workpiece to be measured can collide with the striker units of different heights in sequence to realize the electrical connection between the workpiece to be measured, the corresponding striker units and the first circuit board, so that the first circuit board generates a collision electric signal and transmits the collision electric signal to the energy supply and signal conversion module; the energy supply and signal conversion module can provide electric energy to the striker module, and can also convert the received collision electric signal into a voltage signal and transmit it to the data acquisition module; the data acquisition module can obtain a voltage waveform based on the voltage signal, and use the voltage waveform to obtain the time difference between the collisions of the workpiece to be measured and the two striker units in succession, and also use the time difference and the height difference h to calculate the movement speed of the workpiece to be measured; the overall device has a simple structure, is not limited by the experimental environment, does not require additional external auxiliary devices such as light sources, can be placed in a small space to complete speed measurement, and can realize the movement speed measurement of deformed workpieces in an electromagnetic forming environment.

[0030] 2. The striker unit in the present invention includes two strikers, and the strikers in each striker unit are of the same length. The purpose is to ensure that the workpiece can collide with all the strikers in each striker unit at the same time, ensure the generation of collision electrical signals, and avoid poor contact of a single striker; in addition, the height difference between the vertically arranged long striker and the short striker can be adjusted, the purpose of which is to meet different measurement conditions and actual measurement requirements; the collision ends of all strikers are of the same shape, the purpose of which is to ensure that all strikers of the same height can collide with the workpiece at the same time; and the collision end can be a flat head or a pointed cone head. If it is a flat head, it can increase the stability of the output of the collision electrical signal, and if it is a pointed cone head, it can reduce damage to the workpiece.

[0031] 3. In the present invention, the first circuit board and the second circuit board are electrically connected through a first wire-to-board connector and a second wire-to-board connector. The advantage of the wire-to-board connector is that it has a simple structure and can greatly reduce external interference; and the connector units corresponding to the two striker units are electrically connected one by one with the connector units on the power supply and signal conversion module.

[0032] 4. In the present invention, a linear voltage-regulated power supply and a resistance voltage divider circuit are also provided on the second circuit board. The linear voltage-regulated power supply is used to provide a constant voltage to the striker module via the second wire-to-board connector, and the resistance voltage divider circuit is used to convert the collision electrical signal into a voltage signal according to a preset voltage divider ratio and output it to the data acquisition module. Its advantages are simple circuit topology, fewer interference signals, and high signal-to-noise ratio.

[0033] 5. In the application method of the speed measuring device provided by the present invention, the workpiece to be measured is deformed at high speed under the action of high-speed forming force, and collides with the long striker unit first at a certain moment, the circuit topology in the energy supply and signal conversion module changes for the first time, and the output voltage of the energy supply and signal conversion module changes accordingly; the workpiece to be measured collides with the short striker unit at the next moment, and the circuit topology in the energy supply and signal conversion module changes for the second time based on the previous change, and the output of the energy supply and signal conversion module changes accordingly; during the entire collision process, the output voltage of the energy supply and signal conversion module is recorded and stored by the data acquisition module, and a voltage waveform diagram is formed, and then the voltage waveform diagram is analyzed to obtain the time difference between the successive collisions of the workpiece to be measured, and the movement speed of the deformed workpiece is calculated in combination with the height difference between the collision ends of the two striker units; the principle of the entire measurement method is simple, and its data processing method and calculation method are simple and reliable, and the obtained movement speed of the deformed workpiece is accurate.

[0034] 6. In the application method of the speed measurement device provided by the present invention, the height difference h is much smaller than the displacement height H of the deformed workpiece at a specific moment, and is proportional to the theoretical instantaneous velocity v1 of the workpiece to be measured at the specific moment and inversely proportional to the sampling rate f of the data acquisition module. Its function is to ensure that the average velocity of the workpiece within a smaller displacement h is close to the instantaneous velocity of the workpiece when the displacement height is H.

[0035] 7. The application method of the speed measuring device provided by the present invention is as follows: before each measurement, the relative position between the workpiece to be measured and the striker module is adjusted so that the position where the current collision occurs between the workpiece to be measured and the striker module is different from the position where the previous collision occurred, so as to obtain the speed value at any position on the workpiece to be measured, and calculate the average value of multiple speed values, so as to obtain a more accurate value of the movement speed of the workpiece to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic structural diagram of a device for measuring the speed of a deformed workpiece during high-speed forming provided by the present invention;

[0037] Figure 2 2. It is a structural schematic diagram of a striker module of a speed measuring device for a deformed workpiece provided by the present invention;

[0038] Figure 3is a structural diagram of a striker module provided in Example 1 of the present invention;

[0039] Figure 4 This is a schematic diagram of the structure of the energy supply and signal conversion module provided in Example 1 of the present invention;

[0040] Figure 5 is a circuit topology diagram provided by Example 1 of the present invention;

[0041] Figure 6 is a waveform diagram of data collected by the data acquisition module provided in Example 1 of the present invention;

[0042] Figure 7 This is a schematic diagram of the positions of the workpiece to be measured and the striker unit provided in Example 2 of the present invention.

[0043] In the figure: 1-1a-first metal striker, 1-1b-second metal striker, 1-2a-third metal striker, 1-2b-fourth metal striker, 2a-screw, 2b-screw, 3-first circuit board, 4-epoxy resin board, 5a-first connecting unit, 5b-second connecting unit, 6a-first connector, 6b-second connector, 6c-third connector, 7-second circuit board, 8a first battery base, 8b second battery base, 8c third battery base, 9a-first button battery, 9b-second button battery, 9c-third button battery, C-long striker unit, D-short striker unit. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0045] like Figure 1 FIG. 1 is a schematic diagram of a speed measurement device for a deformed workpiece during high-speed forming, comprising a striker module, an energy supply and signal conversion module, and a data acquisition module electrically connected in sequence, wherein:

[0046] like Figure 2As shown, the striker module includes a first circuit board 3 and at least two striker units. The striker units in this embodiment include a long striker unit (C in the figure) and a short striker unit (D in the figure), wherein the long striker unit and the short striker unit are both metal striker units and are vertically arranged on the first circuit board 3. The first circuit board 3 can be fixed on an insulating carrier plate. The height difference h between the long striker unit and the short striker unit can be adjusted based on the measurement conditions to reduce the measurement error. During operation, the workpiece to be measured can collide with the long striker unit and the short striker unit in sequence to achieve electrical connection between the workpiece to be measured, the corresponding striker unit and the first circuit board 3, so that the first circuit board 3 generates a collision electrical signal and transmits the collision electrical signal to the energy supply and signal conversion module.

[0047] The energy supply and signal conversion module is used to provide electrical energy to the striker module and convert the received collision electrical signal into a voltage signal before transmitting it to the data acquisition module;

[0048] The data acquisition module is used to obtain a voltage waveform based on the voltage signal, and obtain the time difference between the workpiece to be measured and the two striker units colliding successively based on the voltage waveform, and then calculate the movement speed of the workpiece to be measured based on the time difference and the height difference h.

[0049] The above-mentioned speed measurement device has low requirements for the experimental environment and does not require additional external auxiliary devices such as additional light sources. It can be placed in a small space to complete speed measurement; the device has low complexity and the system cost is greatly reduced; the waveform processing method of the voltage data is simple and easy to implement, and no complex algorithm is required to calculate the workpiece movement speed.

[0050] In a preferred embodiment, if Figure 4 As shown, the energy supply and signal conversion module includes a second circuit board 7, a second wire-to-board connector is provided on the second circuit board 7, and a first wire-to-board connector is provided on the first circuit board 3. The first wire-to-board connector is electrically connected to the second wire-to-board connector to electrically connect the first circuit board 3 and the second circuit board 7. The wire-to-board connector has the advantages of simple structure and can greatly reduce external interference.

[0051] In a preferred embodiment, a linear voltage-regulated power supply and a resistance voltage divider circuit are also provided on the second circuit board 7, and the second circuit board 7 is electrically connected to the data acquisition module; the linear voltage-regulated power supply is used to provide a constant voltage to the striker module via the second wire-to-board connector; the resistance voltage divider circuit is used to output a corresponding voltage signal to the data acquisition module based on the collision electrical signal according to a preset voltage divider ratio.

[0052] In a preferred embodiment, the aforementioned long striker unit includes two long metal strikers of the same length, and the short striker unit includes two short metal strikers of the same length. All short strikers and long strikers are vertically fixed on the first circuit board 3, and are insulated from each other. The strikers in each striker unit have the same height.

[0053] In a more preferred embodiment, all the strikers are arranged in rows at equal distances, which has the advantage of improving measurement accuracy.

[0054] In a preferred embodiment, the collision ends of the long striker unit and the short striker unit have the same shape; preferably, the collision ends of the long striker unit and the short striker unit are flat heads or pointed cone heads, which has the advantage of increasing the stability of the collision electrical signal output.

[0055] In a preferred embodiment, the first wire-to-board connector ( Figure 2 5) includes a first connecting unit 5a and a second connecting unit 5b, and the second wire-to-board connector includes a third connecting unit 6a and a fourth connecting unit 6b, wherein the first connecting unit 5a is connected to the long striker unit and the third connecting unit 6a, respectively, and the second connecting unit 5b is connected to the short striker unit and the fourth connecting unit 6b, respectively.

[0056] In a preferred embodiment, the second wire-to-board connector further includes a fifth connecting unit 6c, which electrically connects the second circuit board 7 with the data acquisition module to output the collision electrical signal to the data acquisition module.

[0057] In other preferred embodiments, there can be multiple striker units, and the length of each striker unit is different, and every striker unit has a height difference. The workpiece to be measured can collide with the striker units of different lengths in turn, thereby generating richer collision electrical signals, and further providing more voltage signals and more accurate voltage waveforms.

[0058] Example 1

[0059] In this embodiment, the speed measurement device for a deformed workpiece during high-speed forming includes a striker module, a power supply and signal conversion module, and a data acquisition module that are electrically connected in sequence.

[0060] like Figure 3As shown, the striker module includes a long striker unit and a short striker unit, a first wire-to-board connector and a first circuit board 3, wherein the long striker unit and the short striker unit are vertically fixed on the first circuit board 3, and the first circuit board 3 is fixed to the insulating epoxy resin board 4 by two screws (2a and 2b in the figure), and the first wire-to-board connector includes two connecting units, namely a first connecting unit 5a and a second connecting unit 5b; the aforementioned screws are flat-head hexagonal screws, which are used to realize the mechanical connection between the first circuit board 3 and the epoxy resin board 4 and enhance the stability of the entire device; an installation groove is opened in the upper surface of the epoxy resin board 4 to place the first circuit board 3, wherein the depth of the groove should be less than the height of the two striker units, and the height of the two screws should be less than the depth of the groove to ensure that the workpiece to be measured can collide with both striker units.

[0061] The long striker unit includes a first metal striker 1-1a and a second metal striker 1-1b of the same length, and the short striker unit includes a third metal striker 1-2a and a fourth metal striker 1-2b of the same length; the striker is made of conductive material, and solder is stacked at the non-collision end, that is, the connection between the first circuit board 3 for reinforcement.

[0062] The first circuit board 3 is made of non-conductive materials such as glass fiber epoxy resin, and the electrical connection between the striker unit and the external circuit is achieved by printing copper wires on the surface of the first circuit board 3 .

[0063] The first wire-to-board connector (first connection unit 5a and second connection unit 5b) is a coaxial connector, wherein the first connection unit 5a is used to realize the electrical connection between the long striker unit and the power supply and signal conversion module, and the second connection unit 5b is used to realize the electrical connection between the short striker unit and the power supply and signal conversion module.

[0064] In this embodiment, the energy supply and signal conversion module includes a second wire-to-board connector, a second circuit board 7 and a linear regulated power supply.

[0065] like Figure 4 As shown, the linear regulated power supply is composed of a battery base (including a first battery base 8a, a second battery base 8b and a third battery base 8c) and batteries respectively arranged on the battery base (including a first button battery 9a, a second button battery 9b and a third button battery 9c in the figure); the aforementioned batteries are button batteries, and the quantity and model can be selected according to needs; the aforementioned battery base is used to realize the electrical connection between the battery and the second circuit board 7, wherein each battery base matches the model of each button battery.

[0066] The second wire-to-board connector includes a first connector 6a, a second connector 6b and a third connector 6c, wherein the first connector 6a is electrically connected to the first connection unit 5a, the second connector 6b and the second connection unit 5b respectively, and the third connector 6c is electrically connected to the second circuit board and the data acquisition module respectively, and outputs the voltage signal generated on the second circuit board to the data acquisition module.

[0067] In this embodiment, a resistor voltage divider circuit is provided on the second circuit board of the aforementioned energy supply and signal conversion module for converting the received collision electrical signal into a voltage signal; specifically, the topology of the resistor voltage divider circuit is as follows: Figure 5 As shown in a, the third connector 6c is actually connected in parallel to the two ends of the resistor R1 in the resistor voltage divider circuit, and is used to output the voltage across the two ends of the resistor R1. The definition of the resistor voltage divider ratio k is shown in formula (1):

[0068]

[0069] In this embodiment, Figure 5 The circuit topology of the resistor divider circuit shown in a is the circuit state at the initial moment. The resistance values ​​of resistors R1 and R2 satisfy the voltage divider ratio k. Three button batteries serve as linear regulated power supplies, which can also be replaced by other DC power supplies. In the figure, E1, E2, and E3 represent the voltages of the linear regulated power supplies.

[0070] like Figure 6 The figure shows the waveform of the voltage signal output by the energy supply and signal conversion module. Figure 6 In the period from 0 to t1, the workpiece to be measured has not collided with the striker and the striker, and the voltage of the output port is 0 at this time; at time t1, the workpiece to be measured collides with the longer striker unit first, and the longer striker unit is equivalent to a normally open switch ( Figure 3 1-1a and 1-1b are equivalent to the two contacts of the switch. Then the workpiece to be tested collides with the shorter striker unit, which is equivalent to the closing of the two contacts of the normally open switch. At this time, the circuit topology of the resistor divider circuit is transformed into Figure 5 b in the figure indicates that probe A is closed. Since the working parameters of the measuring device (the height difference between the striker units) are manually adjusted before measurement, and the voltages E1, E2, and E3 of the linear voltage regulator are all constant, and the resistance divider ratio k in the resistance divider circuit is also constant, the voltage at the output port rises from 0 V to a constant voltage value U after the collision. The voltage U at the output port is calculated by formula (2):

[0071] U=(E1+E2+E3)×k (2)

[0072] During the period from t1 to t2, the workpiece to be tested is in continuous contact with the long striker unit, the circuit topology of the resistance voltage divider circuit does not change, the output voltage maintains a constant value U, and the waveform enters the "plateau" period;

[0073] At time t2, the workpiece to be measured collides with the short striker unit, and the short striker unit is equivalent to a normally open switch ( Figure 3 1-2a and 1-2b are equivalent to the two contacts of the switch respectively), the collision between the workpiece to be tested and the short striker unit is equivalent to the closing of the two contacts of the normally open switch. At this time, the circuit topology is transformed into Figure 5 In Figure c, the output port is short-circuited, and its voltage drops from a constant value U to 0, that is, probe B is also closed;

[0074] After time t2, the workpiece to be measured is in continuous contact with the long striker unit and the short striker unit, the circuit topology of the resistance voltage divider circuit remains unchanged, and the voltage at its output port remains a constant value of 0.

[0075] Based on the above voltage signal conversion principle, the data acquisition module collects the voltage data output by the resistor divider circuit at a preset sampling rate and fits the following Figure 6 The voltage waveform shown in FIG1 is used to obtain the values ​​of t1 and t2 on the voltage waveform. Since the height difference h between the two striker units is much smaller than the initial height difference H between the workpiece to be measured and the long striker unit, the average speed of the workpiece to be measured during the time period t1 to t2 is equal to the instantaneous speed at time t1. Therefore, the speed value of the workpiece to be measured at time t1 can be obtained by formula (3):

[0076]

[0077] Example 2

[0078] The present invention further provides an application method of the device for measuring the velocity of a deformed workpiece provided in any of the above embodiments, the method comprising:

[0079] S1. Use simulation software to obtain the theoretical speed-time curve and displacement-time curve of the workpiece to be measured, and obtain the displacement height H of the workpiece to be measured at a specific moment, that is, Figure 7 The height H in the middle;

[0080] S2. Place the workpiece to be measured directly above the striker module at a distance H (i.e., the initial height difference), and adjust the height difference between the long striker unit and the short striker unit to be less than 5% H, and store it in the data acquisition module for subsequent calculations;

[0081] The height difference h also satisfies the following relationship:

[0082]

[0083] Where v1 is the theoretical instantaneous velocity of the workpiece to be measured at a specific moment, and f is the sampling rate of the data acquisition module;

[0084] S3, the workpiece to be tested moves up and down at high speed, and when moving, it first hits the long striker unit to connect the resistance voltage divider circuit on the second circuit board 7, that is, Figure 5 The circuit topology of the resistance voltage divider circuit of the energy supply and signal conversion module is converted from a to b, and then the short striker unit is collided. Then the circuit topology of the resistance voltage divider circuit of the energy supply and signal conversion module is converted from b to c, so that the resistance voltage divider circuit is short-circuited, so that the workpiece to be measured and the measuring device are electrically connected or disconnected, thereby generating a collision electrical signal in the first circuit board 3;

[0085] S4, in the energy supply and signal conversion module, the second circuit board 7 receives the collision electrical signal transmitted by the first circuit board 3, and converts the collision electrical signal into a voltage signal through the resistor voltage divider circuit and transmits it to the data acquisition module;

[0086] S5. The data acquisition module records and stores the aforementioned voltage signal and generates a voltage waveform. The time t1 when the long striker unit hits the data acquisition module and the time t2 when the short striker unit hits the data acquisition module are obtained from the voltage waveform to calculate the motion velocity v of the workpiece to be measured. The calculation formula is:

[0087]

[0088] Since the voltage output by the energy supply and signal conversion module is a continuous signal, but the data acquisition module cannot process continuous signals and can only perform discrete acquisition, the higher the sampling rate f of the data acquisition system, the closer the voltage waveform obtained by fitting the discrete data will be to the continuous signal waveform output by the power module;

[0089] S6. Repeat steps S1-S5 multiple times to obtain multiple motion speeds, and calculate the average of the multiple motion speeds to obtain the actual motion speed of the workpiece to be measured;

[0090] Before each measurement, the relative position between the workpiece to be measured and the striker module is adjusted so that the position where the workpiece to be measured collides with the striker module is different from the position where the previous collision occurred, so as to obtain the velocity value at any position on the workpiece to be measured.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for measuring the speed of a workpiece deformed during high-speed forming, characterized in that: It includes a striker module, an energy supply and signal conversion module and a data acquisition module which are electrically connected in sequence, wherein: The striker module comprises a first circuit board (3) and at least two striker units, wherein the striker units are vertically arranged on the first circuit board (3), and the height of each striker unit is different, and the height difference between adjacent striker units is h It can be adjusted based on the measurement conditions; when working, the workpiece to be measured can collide with the striker units of different heights in sequence, and the workpiece to be measured generates a collision electrical signal in the first circuit board (3) during the collision process, and the first circuit board (3) transmits the collision electrical signal to the energy supply and signal conversion module; The energy supply and signal conversion module is used to provide electrical energy to the striker module and convert the received collision electrical signal into a voltage signal and transmit it to the data acquisition module; The data acquisition module is used to fit the voltage waveform based on the voltage signal, and obtain the time when the workpiece to be tested collides with each of the striker units based on the voltage waveform, and then obtain the time and height difference based on the time and height difference. h To calculate the moving speed of the workpiece to be measured.

2. The speed measuring device according to claim 1, wherein The energy supply and signal conversion module comprises a second circuit board (7), a second wire-to-board connector is provided on the second circuit board (7), a first wire-to-board connector is provided on the first circuit board (3), and the first wire-to-board connector is electrically connected to the second wire-to-board connector, so that the first circuit board (3) and the second circuit board (7) are electrically connected.

3. The speed measuring device according to claim 2, wherein: A linear voltage-regulated power supply and a resistance voltage-dividing circuit are also provided on the second circuit board (7), and the second circuit board (7) is electrically connected to the data acquisition module; the linear voltage-regulated power supply is used to provide a constant voltage to the striker module via the second wire-to-board connector; the resistance voltage-dividing circuit is used to output the voltage signal to the data acquisition module based on the collision electrical signal according to a preset voltage-dividing ratio.

4. The speed measuring device according to claim 1, wherein: Each of the striker units comprises two strikers, and all the strikers are vertically fixed on the first circuit board (3), the two strikers have the same height, and adjacent strikers are insulated from each other.

5. The speed measuring device according to claim 4, wherein: All firing pins are arranged in rows at equal distances.

6. The speed measuring device according to claim 4, wherein: The striking ends of all striker units have the same shape.

7. The speed measuring device according to claim 6, wherein: The collision end of the striker unit is a flat head or a pointed cone head.

8. The speed measuring device according to claim 2, wherein: The first wire-to-board connector includes the same number of connection units as the striker units, and the second wire-to-board connector includes the same number of connection units as the striker units, wherein the connection units on the first wire-to-board connector are respectively connected one-to-one with the connection units on the striker units and the second wire-to-board connector.

9. The speed measuring device according to claim 2, wherein: The second wire-to-board connector further includes a transmission connection unit electrically connected to the data acquisition module, and the transmission connection unit is used to output the collision electrical signal to the data acquisition module.

10. An application of the speed measuring device according to any one of claims 1 to 9, characterized in that: The application steps include: S1. Determine the displacement height of the workpiece at a specific moment based on the theoretical speed-time curve and displacement-time curve of the workpiece. H ; S2. Place the workpiece to be tested at a distance of 1 / 4 from the striker unit. H and the height difference between adjacent striker units h Adjust to h Less than 5% H ; S3, causing the workpiece to be measured to move up and down at high speed, and first colliding with the higher striker unit, and then colliding with the lower striker unit, so that the workpiece to be measured is electrically connected to the measuring device, and a collision electrical signal is generated in the first circuit board (3) during the continuous collision process; S4, the energy supply and signal conversion module receives the collision electrical signal transmitted by the first circuit board (3), and converts the collision electrical signal into a voltage signal and transmits it to the data acquisition module; S5, the data acquisition module generates a voltage waveform based on the voltage signal, and obtains the occurrence time of the striker unit with a higher collision based on the voltage waveform t 1 and the moment of collision of the lower striker unit t 2. To calculate the movement speed of the workpiece to be measured v ; S6. Repeat steps S1-S5 multiple times to obtain multiple movement speeds, and calculate an average value of the multiple movement speeds. The average value is the actual movement speed of the workpiece to be measured.

11. Use of the speed measuring device according to claim 10, characterized in that: In step S2, the height difference h The following relationship is also satisfied: in, v 1 is the theoretical instantaneous speed of the workpiece to be measured at a specific moment, f is the sampling rate of the data acquisition module.

12. Use of the speed measuring device according to claim 10, characterized in that: In step S6, before each measurement, the relative position between the workpiece to be measured and the striker unit is adjusted so that the position where the workpiece to be measured and the striker unit collide with each other is different from the position where the previous collision occurred, so as to obtain the velocity value at any position on the workpiece to be measured.

Images