Electromagnetically-driven FDM printer probe matrix substrate and operation method thereof

Abstract

The invention provides an electromagnetically-driven FDM printer probe matrix substrate. The electromagnetically-driven FDM printer probe matrix substrate comprises a matrix substrate body, probes, probe sliding rails, reset springs and driving electromagnets. Wherein the matrix substrate is provided with a plurality of matrix holes, and the position of each matrix hole is located on a matrix point; the probes are embedded in the matrix holes; the probe is in sliding connection with the probe sliding rail; the upper end of a linear reset spring capable of ensuring the movement of the probe is connected with the probe, and the lower end is connected with the driving electromagnet; and the driving electromagnet is embedded in the matrix substrate. And each driving electromagnet is connected with a processor, and the processor is connected with a power supply. According to the invention, separation under unmanned intervention is realized by driving the probe to move back and forth along the normal of the substrate through the electromagnet, so that the bottom of the sample piece is separated from the substrate and the probe, and finally, the bottom of the sample piece is separated from the real substrate.

Description

Technical Field

[0001] The invention belongs to the field of fiber composite material fused deposition printing technology printer substrates, in particular to an electromagnetically driven FDM printer probe matrix substrate and an operation method thereof. Background Art

[0002] Additive manufacturing technology, commonly known as 3D printing technology, refers to a manufacturing technology that realizes the manufacturing of required parts by gradually adding materials. 3D printers are essential equipment for this process. Fused deposition 3D printers melt polymer composite materials by heating and then extrude them, and cooperate with the printing nozzle to move along a specified path in a plane to stack the molten composite materials layer by layer to achieve manufacturing. Usually the printer consists of: X, Y, Z motion modules, molding modules, control modules and substrates.

[0003] The substrate is an important part of the FDM printer. It supports the first layer of printing materials, and the molded parts are printed on the substrate. Usually, in order to improve the bonding quality between the substrate and the polymer, it is achieved by heating the substrate, spraying adhesives, adding coatings, etc. After printing is completed, in order to separate the sample from the substrate, people usually need to use tools such as spatulas to split the contact between the substrate and the sample. This operation cannot be performed without human intervention, and the splitting operation may cause damage to the printed parts. In addition, the stress concentration generated during the subsequent cooling of the polymer will cause the sample to deform to a certain extent.

[0004] At present, 3D printing technology based on the principle of fused deposition is the most mature on-orbit manufacturing technology in the field of space additive manufacturing. However, the existing FDM printers require manual access to separate the sample from the printer after printing, which is difficult to meet the requirements of on-orbit manufacturing. Therefore, it is necessary to consider the development of an FDM printer substrate that can achieve automatic sample separation. In addition, when separating samples, it is necessary to consider the suppression of deformation of the sample during the subsequent cooling process by the separation method. Summary of the invention

[0005] In order to solve the above problems, the present invention discloses an electromagnetically driven FDM printer probe matrix substrate, which can realize the separation of the printed parts and the printed substrate after printing is completed without human intervention; the sample will not be damaged during the separation process; the bottom of the sample is slightly bent by the probe movement before the sample is separated to reduce the deformation caused by stress concentration. The separation without human intervention is to separate the bottom of the sample from the substrate and the probe by driving the probe to move back and forth along the normal line of the substrate by an electromagnet, and finally to separate the bottom of the sample from the entire substrate.

[0006] The invention discloses an electromagnetically driven FDM printer probe matrix substrate, comprising a matrix substrate, a probe, a probe slide rail, a reset spring and a driving electromagnet; wherein the matrix substrate is provided with a plurality of matrix holes, each of which is located at a matrix point; the probe is embedded in the matrix hole; the probe is slidably connected to the probe slide rail; the upper end of a linear reset spring which can ensure the movement of the probe is connected to the probe and the lower end is connected to the driving electromagnet; the driving electromagnet is embedded in the matrix substrate.

[0007] Furthermore, the probe slide rail is arranged on the inner wall of each matrix hole.

[0008] Furthermore, each of the driving electromagnets is connected to a processor, wherein the processor is connected to a power source and can control the magnitude and direction of the current.

[0009] An operation method of an electromagnetically driven FDM printer probe matrix substrate specifically comprises the following steps:

[0010] Step 1: Each probe is numbered according to its position on the matrix substrate; Definition: Each matrix point is numbered as (X, Y), where X is the column number of the matrix point and Y is the row number of the matrix point;

[0011] Step 2: The power supply is connected to the processor, and the processor controls the current flowing to the driving electromagnet; the driving electromagnet acts on the probe, and when a positive current is input, the probe moves upward, and the reset spring connected to the probe is stretched, and the probe pushes the sample upward during the upward movement; when the current disappears, the probe moves downward under the pulling force of the reset spring to return to its original position;

[0012] Step 3: When reverse current is input, the probe moves downward, the reset spring connected to the probe is compressed, and the sample in contact with the top of the probe is separated from the probe; when the current disappears, the probe moves upward and returns to its original position under the thrust of the reset spring.

[0013] Furthermore, the matrix point at the lower left corner of the matrix substrate is set to (1, 1); the column numbers increase from left to right, and the row numbers increase from bottom to top; the driving electromagnet corresponding to each probe has the same number as the probe, and each numbered driving electromagnet is connected to the corresponding interface in the processor.

[0014] Beneficial effects of the present invention:

[0015] 1. The substrate of the present invention can control the movement of a specified probe on the matrix substrate by controlling the current sent by the processor to the driving electromagnet without human intervention, so that the printed component is separated from the substrate, which is conducive to the sampling work without human intervention after the on-track additive manufacturing is completed.

[0016] 2. The present invention realizes the gradual separation of the sample and the substrate by controlling the up and down movement of the probe on the matrix; the probe moves upward to separate the part of the bottom of the sample that contacts the matrix substrate; the probe moves downward to separate the part of the bottom of the sample that contacts the probe. This method is different from the manual separation of the sample and the substrate, and avoids the damage to the sample caused by the manual splitting operation.

[0017] 3. The matrix probe substrate of the present invention can bend the bottom of the sample into a certain shape before separation by controlling the movement of the probe at a specified position, and then completely separate the sample from the substrate after the sample is cooled to a certain temperature to compensate for the deformation caused by stress concentration during the cooling process of the sample after separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional model diagram of the substrate of the present invention;

[0019] Figure 2 It is a cross-sectional view of the substrate probe motion mechanism of the present invention;

[0020] Figure 3 This is a probe driving circuit diagram of the present invention;

[0021] Figure 4 , is a schematic diagram of a printout of this embodiment;

[0022] Figure 5 , is the bending diagram of the sample after printing in this embodiment;

[0023] Figure 6 , is the arched state of the sample in this embodiment.

[0024] List of reference numerals:

[0025] Among them, 1 is a matrix substrate, 2 is a probe, 3 is a probe slide rail, 4 is a return spring, and 5 is a driving electromagnet. DETAILED DESCRIPTION

[0026] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0027] like Figure 1As shown, the matrix substrate 1 is a flat plate with a plurality of matrix holes distributed on the surface, and the position of each matrix hole is located at a matrix point. The probe 2 is embedded in the matrix hole. The probe 2 is connected to the probe slide 3 to ensure the straightness of the movement of the probe 2. The upper end of the reset spring 4 is connected to the probe 2, and the lower end is connected to the driving electromagnet 5. The driving electromagnet 5 is embedded in the matrix substrate 1.

[0028] like Figure 3 As shown, the power supply is connected to the processor, and the processor is connected to the driving electromagnet 5 under each probe 2 with a different number, so as to control the magnitude and direction of the current.

[0029] like Figure 2 As shown, the power supply is connected to the processor, and the processor controls the current flowing to the 5 driving electromagnets. The 5 driving electromagnets act on the 2 probes. When the positive current is input, the 2 probes move upward, and the 4 return springs connected to the 2 probes are stretched. When the current disappears, the 2 probes move downward under the pulling force of the 4 return springs to return to the original position; when the reverse current is input, the 2 probes move downward, and the 4 return springs connected to the 2 probes are compressed. When the current disappears, the 2 probes move upward under the thrust of the 4 return springs to return to the original position.

[0030] like Figure 1 As shown in FIG. 1 , the substrate mainly consists of a matrix substrate and 121 probes that can move along the normal direction of the matrix substrate. The 121 probes are respectively located in each matrix hole of the matrix substrate. Definition: Each matrix point is numbered (X, Y), where X is the column number of the matrix point and Y is the row number of the matrix point; Figure 1 The matrix point in the lower left corner is (1.1); the column numbers increase from left to right, and the row numbers increase from bottom to top. The probes in each numbered matrix can be moved along the substrate normal direction under control.

[0031] like Figure 2 As shown, the specific working mode of the present invention is that the matrix substrate 1 is used to determine the position of the probe 2 in the entire substrate plane; the probe 2 is used to lift the sample upward during the upward movement, so that the bottom of the sample other than the sample in contact with the top surface of the probe 2 is separated from the substrate; when the probe 2 moves downward, the bottom of the sample is pulled downward, so that the sample in contact with the top of the probe 2 is separated from the probe 2 except the sample in contact with the substrate.

[0032] The function of the probe slide 3 is to limit the movement of the probe in the plane of the substrate and ensure the straightness of the probe in the normal direction of the substrate. The function of the reset spring 4 is to reset the probe moving upward or downward to the original position of the probe after the action of the electromagnet ends (the top plane of the probe is in the same plane as the upper surface of the substrate). The function of the electromagnet 5 is to receive the current from the processor and use the current from the processor to drive the probe to move. The probe moves upward when the current is positive, and moves downward when the current is reverse.

[0033] This embodiment uses a probe fine-tuning method to bend the bottom of the sample into a certain shape before separation by using the movement of the probe, and then completely separates the sample from the substrate after the sample cools to a certain temperature, so as to compensate for the deformation caused by the stress concentration problem during the cooling process of the sample after separation; the details are as follows:

[0034] For FDM printing, the filament is heated and melted at the nozzle during printing, then extruded and deposited on a specified path, and solidified after the temperature drops. During this process, the polymer matrix in the filament will undergo significant thermal expansion and contraction, such as Figure 4 As shown in the figure, the printed length of the sample is L; the thickness of the sample is H; the modulus of the wire is E; and the warpage of the sample is D.

[0035] The shrinkage of the filament due to thermal expansion and contraction during the printing process can be calculated according to the following formula:

[0036] ε=α*(T1-T0)

[0037] The stress inside the filament after printing is E*ε, where ε is the amount of shrinkage; α is the linear expansion coefficient of the filament; T1 is the temperature of the material being printed; and T0 is the temperature of the printed part after printing.

[0038] like Figure 5 As shown in the figure, the sample will bend after printing.

[0039] The printed sample is analyzed as a whole, and the bending stress is E(dz) / R, and the coupling stress is:

[0040] σ=E*∈+E(dz) / R

[0041] Where R is the warping radius and d is the distance from the neutral plane to the substrate.

[0042] After printing, the sum of internal stress is zero, and the internal stress and moment are zero:

[0043]

[0044] The combined solution is (E is the material modulus, so E≠0):

[0045]

[0046] From the figure, we can see that the warping deformation can be calculated as:

[0047]

[0048] Substituting R into the warpage D is:

[0049]

[0050] This method can be used to obtain a rough prediction of the amount of warpage before printing a standard test piece.

[0051] On this basis, define is the compensation slope of the substrate to the sample, the compensation distance is h, and the distance between the probe and the middle position probe is s. Make the probes on both sides of the sample and the substrate at the same level, and raise the position of the probes at the lower end of the sample from both sides to the middle of the printed part so that the sample is in the following position: Figure 6 The arched state shown.

[0052] Assume the number of layers being printed is x, the thickness of the printed layer is b, and the distance each probe is raised is calculated according to the following formula:

[0053]

[0054] The deformation of the sample can be compensated in the above manner. In this state, the sample can be separated from the substrate even if the temperature of the sample has not completely dropped to room temperature.

[0055] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above technical features.

Claims

1. An electromagnetically driven FDM printer probe matrix substrate, characterized in that: The invention comprises a matrix substrate (1), a probe (2), a probe slide rail (3), a reset spring (4) and a driving electromagnet (5); wherein the matrix substrate (1) is provided with a plurality of matrix holes, each matrix hole being located at a matrix point; the probe (2) is embedded in the matrix hole; the probe (2) is slidably connected to the probe slide rail (3); the upper end of the reset spring (4) is connected to the probe (2) and the lower end is connected to the driving electromagnet (5); and the driving electromagnet (5) is embedded in the matrix hole of the matrix substrate (1).

2. The electromagnetically driven FDM printer probe matrix substrate according to claim 1, characterized in that: The probe slide rail (3) is arranged on the inner wall of each matrix hole.

3. The electromagnetically driven FDM printer probe matrix substrate according to claim 1, characterized in that: Each of the driving electromagnets (5) is connected to a processor, wherein the processor is connected to a power source.

4. A method for operating an electromagnetically driven FDM printer probe matrix substrate, characterized in that: The specific steps include: Step 1: Each probe (2) is numbered according to its position on the matrix substrate (1); Definition: Each matrix point is numbered (X, Y), where X is the column number of the matrix point and Y is the row number of the matrix point; Step 2: The power supply is connected to the processor, and the processor controls the current flowing to the driving electromagnet (5); the driving electromagnet (5) acts on the probe (2), and when a positive current is input, the probe (2) moves upward, and the reset spring (4) connected to the probe (2) is stretched, and the probe (2) pushes the sample upward during the upward movement; when the current disappears, the probe (2) moves downward to return to its original position under the pulling force of the reset spring (4); Step 3: When a reverse current is input, the probe (2) moves downward, the return spring (4) connected to the probe (2) is compressed, and the sample in contact with the top of the probe (2) is separated from the probe (2); when the current disappears, the probe (2) moves upward to return to its original position under the thrust of the return spring (4); Step 4: Through the probe fine-tuning method, the movement of the probe is used to bend the bottom of the sample into a certain shape before separation. After the sample is cooled to a certain temperature, the sample is completely separated from the substrate to compensate for the deformation caused by the stress concentration problem during the cooling process of the sample after separation.

5. The method for operating the electromagnetically driven FDM printer probe matrix substrate according to claim 4, characterized in that: The matrix point at the lower left corner of the matrix substrate (1) is set to (1, 1); the column numbers increase from left to right, and the row numbers increase from bottom to top; the driving electromagnet (5) corresponding to the bottom of each probe (2) is numbered the same as the probe (2), and each numbered driving electromagnet (5) is connected to a corresponding interface in the processor.

6. The method for operating the electromagnetically driven FDM printer probe matrix substrate according to claim 4, characterized in that: The method for fine-tuning the probe in step 4 is specifically as follows: Step 41: During the printing process, the filament is heated and melted at the nozzle, then extruded and deposited on a specified path, and solidified and formed after the temperature drops. During this process, the polymer matrix in the filament will undergo significant thermal expansion and contraction. Suppose the printed length of the sample is L; the thickness of the sample is H; the modulus of the filament is E; and the warpage of the sample is D. The shrinkage of the filament due to thermal expansion and contraction during the printing process is calculated according to the following formula: ε=α*(T1-T0) The stress inside the wire after printing is E*ε; where ε is the amount of shrinkage; α is the linear expansion coefficient of the wire; T1 is the temperature of the material being printed; T0 is the temperature of the print after printing'' Step 42: After printing, the sample will bend; if the printed sample is analyzed as a whole, the bending stress is E(dz) / R, and the coupling stress is: σ=E*∈+E(dz) / R Where R is the warping radius, d is the distance from the neutral plane to the substrate; After printing, the sum of internal stress is zero, and the internal stress and moment are zero: The combined solution is that E is the material modulus, so E≠0: The warping deformation can be calculated as: D=R-Rcosθ θ=L / 2R Substituting R into the warpage D is: This method can be used to obtain a rough prediction of the amount of warpage before printing a standard test piece. Step 43: Based on this, it is defined as The compensation slope of the substrate to the sample, the compensation distance is h, and the distance between the probe and the middle position probe is s. Make the probes on both sides of the sample and the substrate at the same level, and raise the positions of the probes at the lower end of the sample from both sides to the middle of the printed part, so that the sample is in an arched state; Assume that the number of layers being printed is x, the thickness of the printed layer is b, and the distance each probe is raised is calculated according to the following formula: The deformation of the sample is compensated by the above method. In this state, even if the temperature of the sample has not completely dropped to room temperature, the sample can be separated from the substrate.

Images