3D printer strain sensor, 3D printing head assembly and 3D printer

Abstract

The application provides a strain sensor, comprising a fixed plate and a strain gauge, the fixed plate comprising a first support part and a second support part, the second support part being elastically connected with the first support part, and the second support part being provided with the strain gauge. The application has the beneficial effects that the strain sensor has simple structure, high reliability and high sensitivity, the horizontal or not of the contact surface can be obtained through the small deformation, and the elastic fixed plate can provide certain buffer for the equipment, so that the damage of the equipment caused by the direct acting force is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing device, in particular to a strain sensor, a 3D printing head assembly and a 3D printer. BACKGROUND

[0002] The 3D printer is mainly of the inverted printing type, so when printing products, the first layer must be horizontal. When the plane is not horizontal, the difference is compensated by recording the distance between the printing head and the plane. This process is called leveling.

[0003] The existing leveling method through the rudder can install the micro switch on the rudder. The micro switch is lowered before leveling and is retracted after leveling. However, due to the distance between the installation position of the rudder and the nozzle, the measured value has an error, and the subsequent manual error correction method is complicated.

[0004] The prior art needs to be improved. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a printing assembly with simple structure, novel design, convenient operation and leveling function.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a strain sensor, comprising a fixed plate and a strain gauge, the fixed plate comprising a first support part and a second support part, the second support part being elastically connected with the first support part, and the second support part being provided with a strain gauge.

[0007] Further, the fixed plate is provided with a hollow part, the second support part is arranged in the hollow part, and one end of the second support part is connected with one end of the hollow part.

[0008] Further, the first support part and the second support part are perpendicular to each other.

[0009] Further, the material of the fixed plate is metal.

[0010] Further, the fixed plate is a spring steel plate.

[0011] Further, the strain gauge is connected with the second support part by pasting or welding.

[0012] The present application also relates to a 3D printing head assembly, comprising the strain sensor of any one of the above and a printing head, the printing head being fixedly connected with the second support part.

[0013] Further, the second support part is provided with two mounting holes, and a positioning gap is arranged between the two mounting holes.

[0014] Further, the print head comprises a connecting throat, a nozzle, a heating block, a heat dissipation block and a fan, the lower end of the connecting throat is connected with the upper end of the nozzle, the heating block is sleeved on the nozzle, the heat dissipation block is sleeved with the connecting throat, and the fan is fixed on the heat dissipation block.

[0015] The application also relates to a 3D printer comprising the 3D print head assembly according to any one of the above, the 3D printer further comprising a motion device back plate and a control circuit board, the 3D print head assembly is connected with the motion device back plate through the first supporting part, the motion device back plate is provided with at least three pulley mounting positions, each pulley mounting position is provided with a pulley, and the control circuit board is connected with the strain gauge of the 3D print head assembly.

[0016] The application has the advantages that the strain sensor has simple structure, high reliability and high sensitivity, the horizontal or not of the contact surface can be obtained through the small deformation, the elastic fixing plate can provide certain buffer for the equipment, and damage of the equipment caused by direct force can be avoided. The print head is connected with the printer through the strain sensor, whether the printing platform and the print head are flat can be detected through the deformation of the strain sensor, and the distance between the print head and the printing platform is controlled, so that automatic leveling is realized. BRIEF DESCRIPTION OF DRAWINGS

[0017] The specific structure of the application will be described in detail below with reference to the drawings:

[0018] Figure 1 It is a schematic diagram of the overall structure of the strain sensor of the application;

[0019] Figure 2 It is a schematic diagram of the overall structure of the 3D print head assembly of the application;

[0020] Figure 3 It is a schematic diagram of the exploded structure of the 3D print head assembly of the application;

[0021] Figure 4 It is a schematic diagram of the structure of the 3D print head assembly and the motion device back plate of the application;

[0022] 10 - fixing plate; 11 - first supporting part; 12 - second supporting part; 13 - strain gauge; 14 - positioning notch; 21 - connecting throat; 22 - nozzle; 23 - heating block; 24 - heat dissipation block; 25 - fan; 26 - wind deflector; 31 - quick connector; 32 - quick connector buckle; 41 - motion device back plate; 42 - pulley. DETAILED DESCRIPTION

[0023] In order to explain the technical content, structural features, achieved purposes and effects of the present application in detail, the following will be described in detail in combination with the embodiments and the accompanying drawings.

[0024] Embodiment 1

[0025] Please refer to Figure 1 A strain sensor comprises a fixed plate 10 and a strain gauge 13, the fixed plate 10 comprises a first support part 11 and a second support part 12, the first support part 11 and the second support part 12 are perpendicular to each other, the second support part 12 is elastically connected with the first support part 11, specifically, the fixed plate 10 is provided with a hollow part, the second support part 12 is arranged in the hollow part, and one end of the second support part 12 is connected with one end of the hollow part. In order to facilitate connection, two fixing holes are arranged on the first support part 11, and two mounting holes are arranged on the second support part 12.

[0026] The second support part 12 is provided with a strain gauge 13 close to the side connected with the fixed plate 10, specifically, the strain gauge 13 is connected with the second support part 12 by pasting or welding, and the strain gauge 13 is a resistance strain gauge.

[0027] The material of the fixed plate 10 is metal, preferably, the fixed plate 10 is a spring steel plate. The fixed plate made of metal can reliably fix the print head, and at the same time has a certain elastic deformation capacity, so that the strain gauge also deforms.

[0028] In order to further increase the structural strength of the fixed plate, the first support part and the second support part are an integral structure.

[0029] From the above description, the beneficial effects of the present application are that a strain sensor with simple structure, high reliability and high sensitivity is provided, the horizontal or not of the contact surface can be obtained through small deformation, the elastic fixed plate can provide a certain buffer for the equipment, and damage of the equipment caused by direct force is avoided.

[0030] Embodiment 2

[0031] Please refer to Figure 2 and Figure 3 The present application also relates to a 3D print head assembly comprising the above-mentioned strain sensor and a print head, the second support part 12 of the strain sensor is fixedly connected with the print head through the mounting hole, in order to avoid that the second support part blocks the print material from being delivered to the print head, and to facilitate the installation of the print head to the second support part, a positioning gap 14 is further arranged between the two mounting holes of the second support part.

[0032] In the printing process, if the print head contacts the printing platform, the print head will be affected by the external force of the printing platform, the external force is transmitted to the second support part through the print head, the deformation between the second support part and the fixed plate is caused, and then the strain gauge is affected, the strain gauge is deformed, the resistance value of the strain gauge is changed, the resistance change is converted into voltage change through the control circuit, and it can be confirmed that the external force is applied to the print head, that is, the printing platform has the force on the print head, the main control chip can detect the voltage change of the resistance strain gauge, at this time, the printer controls the print head to move away from the printing platform, so that automatic leveling is realized.

[0033] The fixed plate made of metal material can reliably fix the print head, and at the same time can have a certain elastic deformation capacity, so as to provide buffer for the print head, and avoid damage of the print head caused by direct force.

[0034] The print head comprises a connecting throat pipe 21, a nozzle 22, a heating block 23, a heat dissipation block 24 and a fan 25, the lower end of the connecting throat pipe 21 is connected with the upper end of the nozzle 22, the heating block 23 is sleeved on the nozzle 22, the heat dissipation block 24 is sleeved on the connecting throat pipe 21, and the fan 25 is fixed on the heat dissipation block 24.

[0035] The heat dissipation block arranged outside the connecting throat pipe can avoid that the heat generated by the heating block is conducted to the upper part of the connecting throat pipe, so that the printing consumables are melted in advance and the connecting throat pipe is blocked. The fan can further enhance the heat dissipation capacity of the heat dissipation block. In order to uniformly guide the wind of the fan to the heat dissipation fin, a wind guide cover 26 is further arranged between the heat dissipation fin and the fan.

[0036] In order to conveniently input the printing material into the connecting throat pipe, the print head further comprises a quick connector 31 and a quick buckle 32, one end of the quick connector 31 is connected with a material conveying pipe, the other end of the quick connector 31 is connected with a connecting hole at the top of the heat dissipation block, at least two clamping claws are arranged at the end of the quick connector 31 connected with the connecting hole, gaps are arranged between adjacent two clamping claws, fixed protrusions are arranged at the outer edges of the clamping claws, and fixed grooves are arranged on the inner walls of the connecting hole and correspond to the fixed protrusions. Since there is a gap for the movement of the quick connector after the quick connector is inserted into the connecting hole, the quick buckle is clamped between the quick connector and the heat dissipation block, and the relative displacement of the quick connector and the connecting throat pipe can be prevented.

[0037] As known from the above description, the 3D print head assembly with leveling detection function provided by the application has the advantages of small size, simple structure, convenient installation and low cost, and the printer adopting the 3D print head assembly can automatically adjust the distance between the 3D print head assembly and the printing plane through the deformation of the strain gauge and the fixed plate, so that automatic leveling is realized.

[0038] Example 3

[0039] Please refer to Figure 4 The present application also relates to a 3D printer, which comprises the 3D printing head assembly described above, and further comprises a motion device back plate 41 and a control circuit board, the 3D printing head assembly is connected with the motion device back plate through the first support part, the motion device back plate is provided with at least three pulley mounting positions, each pulley mounting position is provided with a pulley 42, and the control circuit board is connected with the strain gauge of the 3D printing head assembly.

[0040] In the embodiment, the 3D printer is a gantry structure, the gantry can reciprocate in the X-axis direction of the printing platform, the gantry is provided with a cross rail, the 3D printing head assembly can reciprocate in the Y-axis direction on the cross rail of the gantry through the pulley, the cross rail can reciprocate in the Z-axis direction of the gantry, the X-axis, the Y-axis and the Z-axis are perpendicular to each other.

[0041] The 3D printing head assembly described above has the advantages of small size, convenient installation and low cost because the leveling structure adopts a spring steel plate and a strain gauge, the structure of the spring steel plate and the strain gauge does not occupy the nozzle space, the detection effect is good, the complicated manual leveling operation is omitted, the 3D printer can print more finely and stably without sacrificing the performance of the printer, and the printing success rate is effectively improved.

[0042] In addition, in order to improve the sensitivity of the strain gauge, the strain gauge is connected with the control circuit board in a full-bridge bridge circuit.

[0043] In the above, up, down, left, right, front and back only represent relative positions and do not represent absolute positions.

[0044] The above only describes the embodiments of the present application, and does not limit the patent scope of the present application, any equivalent structure or equivalent process transformation according to the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A 3D printing head assembly, characterized in that: The device includes a strain sensor and a printhead. The strain sensor includes a fixed plate and a strain gauge. The fixed plate includes a first support portion and a second support portion. The second support portion is elastically connected to the first support portion. A strain gauge is provided on the second support portion. The printhead is fixedly connected to the second support portion. The fixed plate has a hollowed-out portion, and the second support portion is disposed in the hollowed-out portion. One end of the second support portion is connected to one end of the hollowed-out portion; the strain gauge is a resistance strain gauge.

2. The 3D printing head assembly as described in claim 1, characterized in that: The first support portion and the second support portion are perpendicular to each other.

3. The 3D printing head assembly as described in claim 2, characterized in that: The fixing plate is made of metal.

4. The 3D printing head assembly as described in claim 3, characterized in that: The fixing plate is a spring steel plate.

5. The 3D printing head assembly as described in claim 4, characterized in that: The strain gauge is connected to the second support by means of adhesive bonding or welding.

6. The 3D printing head assembly as described in claim 5, characterized in that: The second support part is provided with two mounting holes, and a positioning notch is provided between the two mounting holes.

7. The 3D printing head assembly as described in claim 6, characterized in that: The printhead includes a connecting throat, a nozzle, a heating block, a heat sink, and a fan. The lower end of the connecting throat is connected to the upper end of the nozzle. The heating block is fitted onto the nozzle. The heat sink is fitted onto the connecting throat. The fan is fixed to the heat sink.

8. A 3D printer, characterized in that: The 3D printer includes a 3D print head assembly as described in any one of claims 1-7, and further includes a motion device backplate and a control circuit board. The 3D print head assembly is connected to the motion device backplate via the first support portion. The motion device backplate is provided with at least three pulley mounting positions, each pulley mounting position being provided with a pulley. The control circuit board is connected to the strain gauge of the 3D print head assembly.

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