CN104625060A - Three-dimensional printing processing method of multi-dimension force sensor elastic body - Google Patents

Abstract

A 3D printing processing method for elastic bodies of multi-dimensional force sensors. According to the multi-dimensional force sensor configuration theory, three-dimensional drawing software is used to draw a three-dimensional model of elastic bodies; stress analysis is performed on the model to determine the three-dimensional model of elastic bodies; the three-dimensional model is divided into Z-direction A series of two-dimensional graphics of equal thickness are converted into STL format that the printer can recognize and input to the 3D printer; the printer spreads powder with a scraper according to the thickness of each layer, and the laser head performs selective sintering according to the two-dimensional graphics of the model, and repeats powder coating and sintering , until the printing is completed; the printed part is taken out and subjected to annealing stress relief treatment, surface shot blasting treatment, and mechanical aging. Compared with the prior art, the invention has the advantages of being able to realize the processing of highly complex elastic body, high processing precision, fast efficiency and the like.

Description

A 3D printing processing method for elastic body of multi-dimensional force sensor

Technical Field The present invention belongs to the field of multi-dimensional force sensor processing, and in particular relates to a method for processing elastic bodies of multi-dimensional force sensors.

Background technology The elastic body of the multi-dimensional force sensor is the core component of the sensor that can detect the force. The elastic body senses the external force and deforms, and the magnitude and direction of the external force can be obtained through theoretical conversion by detecting the amount of deformation. In order for the elastic body to sense the external force more accurately, it is necessary to make the elastic body material as uniform and isotropic as possible, and local material properties are not allowed to vary; and the sensor structure has high dimensional accuracy requirements, and there is no gap between the sensor components, so the elastic body One-piece molding is the best choice.

The processing of the elastic body of the existing multi-dimensional force sensor can be processed by a multi-axis linkage machining center, but the processing cost is high, it takes a long time, and the technical requirements are high. For the elastic body of a highly complex sensor, the traditional cutting method has no way to start, so it is greatly limited. the development of sensors. The assembly method can also be used to split the whole into multiple modules and process them separately, and then combine the modules into a whole by laser welding or other connection methods, but when the assembly method is used, displacement and friction will inevitably occur at the connection , increasing the nonlinearity, hysteresis and repeatability error, the sensor accuracy is difficult to guarantee. Therefore, the existing elastomer processing methods are suitable for large-scale processing with regular shapes, no curved surfaces, no thin ribs, no thin walls, and are not suitable for highly complex elastomers with irregular shapes such as thin walls, slopes, and curved surfaces. Suitable.

SUMMARY OF THE INVENTION The purpose of the present invention is to provide a processing method capable of processing highly complex elastic bodies in multi-dimensional force sensors, with high processing accuracy, fast efficiency, and time-saving and labor-saving processing.

The present invention is mainly aimed at the processing method of the elastic body of the highly complex multi-dimensional force sensor, and the specific steps are as follows:

(1) According to the configuration theory of the multi-dimensional force sensor, use the 3D software to draw the 3D model of the elastic body;

(2) Perform stress analysis on the model, simulate sensor calibration, and determine the three-dimensional model of the elastic body;

(3) Divide the three-dimensional model into a series of (several) equal-thick two-dimensional graphics in the Z direction, and convert it into an STL format that the printer can recognize and input it into the 3D printer;

(4) The printer spreads powder with a scraper according to the thickness of each layer, and the laser head performs selective sintering according to the two-dimensional graphics of each layer of the model, and repeats powder spreading and sintering until the printing is completed;

(5) Take out the printed part and perform annealing stress relief treatment, surface shot peening treatment, mechanical artificial aging.

Further, in order to reduce the micro-deformation generated during printing and stress relief treatment, and improve the shape and position accuracy of the elastic body, according to the specific shape and structure of the elastic body, draw a three-dimensional support frame model that matches the three-dimensional model, which is divided and input at the same time as the three-dimensional model of the elastic body For 3D printers, after the printed parts are completed, they are annealed to relieve stress, and the support frame is partially removed, and then shot peened and artificially aged.

The 3D printer is a commercially available conventional product, such as the EOSINT M280 3D printer.

The drawing of the three-dimensional model of the elastic body generally adopts three-dimensional software such as SolidWorks, ProE, UG, and Catia.

The stress analysis of the model generally uses Ansys and other software combined with MATLAB and other data processing software for stress analysis and virtual calibration to verify whether the three-dimensional elastic body model can meet design requirements such as accuracy, linearity, sensitivity, and repeatability.

The division of the three-dimensional model into two-dimensional graphics of equal thickness generally adopts three-dimensional software matched with the 3D printer, such as ProE, UG and the like.

The powder coating can be made of titanium alloy, aluminum alloy, alloy structural steel, stainless steel and other multi-dimensional force sensor elastic body.

The 3D printer uses its own SLS selective laser sintering technology for selective sintering according to the three-dimensional model during laser sintering.

This invention replaces the traditional method of mechanical cutting and processing multi-dimensional force sensor elastic body, and proposes a method of using high-precision 3D printing technology to process small volume, thin walls, thin ribs, elastic spherical hinges, slopes, curved surfaces, etc. The highly complex elastomer method with regular shape, while ensuring the uniform texture of the elastomer material and the characteristics of no stress residue, has opened up new ideas for the processing of elastomers. The proposal of the present invention breaks the idea of processing elastic bodies of multi-dimensional force sensors by cutting and removing materials, greatly accelerates the research and development process of multi-dimensional force sensors, reduces its production cost, and makes up for the inability to produce highly complex elastic materials. body vacancy.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of the main process flow of an embodiment of the present invention.

Fig. 2 is a schematic diagram of the structure of the elastomer of the embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a support frame according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments

Applications

This embodiment takes the processing of the elastic body of the multi-dimensional force sensor as shown in Figure 2 as an example. Through hole 5, the interior of the elastomeric outer ring has an inner ring coaxial with it, and there are 8 wires between the inner ring and the outer ring, one end of which is connected to the inner peripheral surface of the outer ring, and the other end is connected to the outer peripheral surface of the inner ring. branch rods, the branch rods are all connected to the inner ring and the outer ring through elastic spherical hinges, the center line of the branch rods does not intersect the axis of the inner ring or the outer ring, and the center line of the branch rods is not parallel to the horizontal plane; Inside the outer ring, there is an ear for sealing wires with its end protruding from its circumferential surface. The protruding part of the ear for sealing wires has a curved surface. In summary, this kind of elastic body is typically thin ribbed and complex. Curved surfaces, small local dimensions, and extremely difficult workpieces for mechanical cutting.

The method for the elastomer shown in the processing Fig. 2 is as follows, as shown in Fig. 1:

(1) First construct the multidimensional force sensor configuration theory according to the Stewart theory, and use the SolidWorks 3D software to draw the 3D model of the elastic body shown in Figure 2;

(2) Lead the three-dimensional model of the elastic body to Ansys software, combine the MATLAB software to simulate the calibration process, conduct stress analysis, and preliminarily verify that the elastic body configuration can meet the design requirements such as accuracy, linearity, sensitivity, and repeatability;

(3) According to the structure of the three-dimensional model, make a matching support frame model, as shown in Figure 3, the support frame has an outer support ring 6 that is all the same as the inner diameter and outer diameter of the elastomeric outer ring, the outer support ring There is an inner support ring 7 having the same inner diameter and outer diameter as the inner ring of the elastomer, and there are 8 inner support blocks 8 respectively corresponding to the branch rods of the elastomer between the outer support ring and the inner support ring. The lower end surface of the outer ring of the elastic body is connected with the upper end surface of the outer support ring to realize the support of the outer ring, and the lower end surface of the inner ring of the elastic body is connected with the upper end surface of the inner support ring to realize the support for the inner ring, The lower end surface of each branch rod of the elastic body is in contact with the upper end surface of the corresponding lower inner support block to support the branch rod.

(4) The three-dimensional model combined with the elastic body and the support frame is cut along the Z direction into several two-dimensional graphics with a thickness of 0.05mm, and converted into an STL format that the printer can recognize and input to the EOSINT M280 3D printer. The computer prepares the bottom two-dimensional graphics, and the printer parameters: the printing scanning speed is 5m/s, the scanning distance is 0.09mm, the laser power is 400W, the powder is made of titanium alloy powder, and the particle size is 100-1000 mesh. After the bottom layer is printed , the printer controls the scraper to lay down a layer of titanium alloy powder. Under the control of the computer, the laser head selectively sinters the solid part of the powder according to the interface profile information of the bottom two-dimensional graphic, and sinters the powder in time. At the same time, the computer is ready for the next layer. Two-dimensional graphics, after the sintering is completed, the printer table lowers the height of a layer of powder, the scraper spreads the powder again, the laser head continues selective sintering according to the interface contour information of the two-dimensional graphics, merges with the previous layer, repeats the powder coating and sintering until printing Finish;

(6) Take out the printed part, keep it warm at 650-800°C for 1-10h, stress-relief annealing to eliminate the internal stress of the material, then remove the support frame, use a shot-peening machine to perform shot-peening treatment on the surface of the elastomer to improve the surface quality, and use vibration The platform performs artificial aging on the elastic body with a frequency of 35 Hz, a vibration acceleration of 10 g, and a time of 20 min to release the residual stress of the material.

Claims (6)

1. the elastomeric 3D of multi-dimension force sensor prints a processing method, it is characterized in that:

(1) three-dimensional drawing Software on Drawing is adopted to go out elastomer threedimensional model according to multi-dimension force sensor configuration theory;

(2) carry out stress analysis to model, analog sensor is demarcated, and determines elastomer threedimensional model;

(3) threedimensional model is divided into the X-Y scheme of a series of uniform thickness of Z-direction, and is converted into the STL form input 3D printer printing function identification;

(4) printer carries out scraper paving powder according to every layer thickness, and laser head carries out selective sintering according to model X-Y scheme, repeats to spread powder, sintering, until printed;

(5) printout taken out and carry out annealing destressing process, shot blasting on surface process, mechanical artificial aging.

2. the elastomeric 3D of multi-dimension force sensor according to claim 1 prints processing method, it is characterized in that: after step (2) completes, can according to the concrete contour structures of elastomer, draw out the three-dimensional support frame model mated with threedimensional model, itself and elastomer threedimensional model are split simultaneously and are inputted 3D printer, after printout completes, and annealed destressing process, supporting frame part is removed, then carries out bead and artificial aging.

3. the elastomeric 3D of multi-dimension force sensor according to claim 1 and 2 prints processing method, it is characterized in that: described 3D printer is EOSINT M2803D printer.

4. the elastomeric 3D of multi-dimension force sensor according to claim 3 prints processing method, it is characterized in that: described drafting elastomer threedimensional model, can adopt any one three-dimensional drawing software in SolidWorks, ProE, UG, Catia.

5. the elastomeric 3D of multi-dimension force sensor according to claim 4 prints processing method, it is characterized in that: describedly carry out stress analysis to model, adopts Ansys software to carry out stress analysis and Virtual Calibration in conjunction with MATLAB data processing software.

6. the elastomeric 3D of multi-dimension force sensor according to claim 5 prints processing method, it is characterized in that: described paving powder can adopt any one material made as multi-dimension force sensor elastomer in titanium alloy, aluminium alloy, structural alloy steel, stainless steel.