Strain sensor, printing head and 3D printer

Abstract

The utility model relates to the technical field of 3D printing, aims to solve the technical problem of low detection sensitivity of some known sensors, and provides a strain sensor, a printing head and a 3D printer. The strain sensor comprises an elastic connecting piece and a detection piece. The elastic connecting piece is provided with a connecting part and a fixing part which are arranged at intervals in the length direction of the elastic connecting piece, the two opposite sides of the middle of the connecting part are inwards concaved in the width direction of the elastic connecting piece to form first grooves, and the first grooves are used for enhancing the elastic deformation capacity of the connecting part. The detection piece is attached to the middle of the surface of one side of the connecting part and used for detecting deformation generated by the elastic connecting piece. And the elastic connecting piece is also provided with an amplification hole between the detection piece and the fixing part. The beneficial effect of the utility model is that the detection sensitivity and the detection precision of the strain sensor are improved.

Description

Technical Field

[0001] The present application relates to the field of 3D printing technology, and in particular to a strain sensor, a print head and a 3D printer. Background Art

[0002] 3D printers construct objects by printing layer by layer. During the printing process of the workpiece, the plane of the first layer must be kept horizontal. If the plane is not horizontal, the difference is compensated by recording the distance between the print head and the plane to complete the leveling of the printing plane.

[0003] The leveling function of the known 3D printer nozzle is mainly achieved by moving the nozzle up and down and contacting the printing platform, and the sensor detects that the nozzle contacts the printing platform, thereby realizing detection. However, in the actual working process of the known 3D printer nozzle, the sensor detection sensitivity is low, resulting in low leveling accuracy, and the nozzle exerts a large force on the printing platform, causing a large deformation of the printing platform, which is easy to damage the printing platform. Utility Model Content

[0004] The present application provides a strain sensor, a print head and a 3D printer to solve the technical problem that some known strain sensors have low detection sensitivity.

[0005] The embodiment of the present application is implemented as follows:

[0006] In a first aspect, the present application provides a strain sensor, comprising an elastic connector and a detection member. The elastic connector has a connecting portion and a fixing portion spaced apart along its length direction, and first grooves are formed inwardly on opposite sides of the middle of the connecting portion and on both sides along the width direction of the elastic connector, and the first grooves are used to guide the elastic connector to deform at the first grooves when the connecting portion is subjected to force and the fixing portion is fixed. The detection member is attached to the middle of one side surface of the connecting portion, and the detection member is used to detect the deformation generated by the elastic connector. The elastic connector is also provided with an enlarged hole between the detection member and the fixing portion.

[0007] The strain sensor of the present application is provided with a first concave groove formed on both sides of the elastic connector along its width direction, so that the width of the elastic connector at the first groove is smaller. When the nozzle assembly abuts the printing platform, the connecting part is subjected to the force from the printing platform, and the fixed part remains fixed. The elastic connector is more likely to bend at a position with a smaller width, that is, where the first groove is provided, thereby driving the detection member at the first groove to deform, thereby ensuring that the detection member can detect the deformation of the elastic connector at this location. The force required for the elastic connector with the first groove to deform is smaller than the force required for the elastic connector without the first groove to produce the same deformation. In this way, the detection sensitivity of the pressure sensor can be improved. Similarly, after the enlarged hole is provided between the detection member and the connecting part, since the elastic connector is hollowed out at this location, the deformation of the elastic connector after the connecting part is subjected to the same force is larger than the deformation of the elastic connector without the enlarged hole. Therefore, the enlarged hole can also achieve the improvement of the deformation of the elastic connector and the detection sensitivity of the strain sensor.

[0008] In one possible implementation:

[0009] The two first grooves are symmetrically arranged along the width direction of the elastic connecting member, the two first grooves are symmetrical about the first symmetry axis, and the edge of the detection member does not exceed the edge of the first groove.

[0010] In one possible implementation:

[0011] The detection member includes a strain gauge, which includes a first part and a second part. The first part and the second part are symmetrical about a second symmetry axis. The second symmetry axis is parallel to the width direction of the elastic connecting member and is located between two oppositely arranged groove sides of the first groove.

[0012] In one possible implementation:

[0013] The connecting portion is provided with a second groove, which is formed inwardly from the middle of the edge of one side of the connecting portion away from the fixing portion along the length direction of the elastic connecting member. The second groove is used to guide the elastic connecting member to deform at the second groove when it bends from one side to the other side in its width direction.

[0014] In one possible implementation:

[0015] The groove surface of the second groove is also provided with a protruding support portion, and a part of the detection member is attached to the support portion.

[0016] In one possible implementation:

[0017] The distance between the first groove and the connecting portion is L1, the distance between the first groove and the fixing portion is L2, and L2 / L1 is between 4 and 7.

[0018] In a second aspect, the present application provides a print head for extruding consumables on a printing platform, the print head comprising a bracket, a nozzle assembly and the aforementioned strain sensor. The bracket is used to connect a transfer device. The nozzle assembly is used to extrude consumables. The fixed portion of the strain sensor is connected to the bracket, the connecting portion of the strain sensor is connected to the nozzle assembly, and the strain sensor is used to be triggered when the nozzle assembly abuts against the printing platform.

[0019] In one possible implementation:

[0020] The print head also includes a transfer component, one end of which is connected to the connection portion, and the other end of which is connected to the nozzle assembly.

[0021] In one possible implementation:

[0022] The nozzle assembly includes a heat sink, a side surface of the adapter abuts against and is connected to the heat sink, and the connecting portion is attached to the bottom surface of the adapter and is connected to the heat sink.

[0023] In a third aspect, the present application provides a 3D printer, comprising a printing platform, the aforementioned print head and a transfer device. The transfer device is connected to the print head and is used to drive the print head to move relative to the printing platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a schematic structural diagram of a 3D printer according to an embodiment of the present application;

[0026] Figure 2 A side exploded view of a print head according to an embodiment of the present application;

[0027] Figure 3 A schematic diagram of the structure of a print head according to an embodiment of the present application;

[0028] Figure 4 This is a schematic diagram of an exploded structure of a print head according to an embodiment of the present application;

[0029] Figure 5This is a schematic diagram of the structure of a strain sensor according to an embodiment of the present application;

[0030] Figure 6 A bottom view of a strain sensor according to an embodiment of the present application;

[0031] Figure 7 FIG. 1 is a top view of a strain sensor according to an embodiment of the present application.

[0032] Description of main component symbols:

[0033]

[0034] DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0036] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a centered element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may also be a centered element. When an element is considered to be "set on" another element, it may be directly set on the other element or there may also be a centered element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present application. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "or / and" used herein includes any and all combinations of one or more related listed items.

[0038] Some embodiments of the present application are described in detail. In the absence of conflict, the following embodiments and features of the embodiments can be combined with each other.

[0039] 3D printers construct objects by printing layer by layer. During the printing process of the workpiece, the plane of the first layer must be kept horizontal. If the plane is not horizontal, the difference is compensated by recording the distance between the print head and the plane to complete the leveling of the printing plane.

[0040] The leveling function of the known 3D printer nozzle is mainly achieved by moving the nozzle up and down and contacting the printing platform, and the sensor detects that the nozzle contacts the printing platform, thereby realizing detection. However, in the actual working process of the known 3D printer nozzle, the sensor detection sensitivity is low, resulting in low leveling accuracy, and the nozzle exerts a large force on the printing platform, causing a large deformation of the printing platform, which is easy to damage the printing platform.

[0041] In view of this, if Figure 1 As shown, the embodiment of the present application provides a 3D printer 300, wherein the strain sensor 100 has a high sensitivity and can improve the leveling accuracy of the 3D printer 300. The following will be exemplified.

[0042] See also Figure 1 The present embodiment provides a 3D printer 300 , including a printing platform 301 , a print head 200 , and a transfer device 302 . The print head 200 is used to extrude consumables onto the printing platform 301 .

[0043] The transfer device 302 is connected to the print head 200 and is used to drive the print head 200 to move relative to the printing platform 301. The transfer device 302 can be specifically configured as a lead screw motor linear module, a cylinder, an electric push rod, etc. For example, the transfer device 302 can be specifically configured as an X-axis Z-axis linear module to achieve driving the print head 200 to move in the horizontal direction and the vertical direction relative to the printing platform 301. In other embodiments, the transfer device 302 can also be configured as a multi-axis manipulator, etc.

[0044] See also Figures 2 to 4 The print head 200 includes a bracket 201, a nozzle assembly 202 and a strain sensor 100. The bracket 201 is connected to the transfer device 302. The nozzle assembly 202 is used to eject consumables. The strain sensor 100 includes an elastic connector 10, and the elastic connector 10 includes a connecting portion 11 and a fixing portion 12 arranged at intervals along its length direction. The fixing portion 12 is connected to the bracket 201, and the connecting portion 11 of the strain sensor 100 is connected to the nozzle assembly 202. The strain sensor 100 is used to be triggered when the nozzle assembly 202 abuts against the printing platform 301.

[0045] Alternatively, see Figure 2 and Figure 3 The bracket 201 is provided with an axial hole 2011 and a mounting hole 2012. The transfer device 302 includes an optical axis, a synchronous belt and a driving member (not shown). The synchronous belt is arranged in the mounting hole 2012 and is connected to the bracket 201. The driving member drives the synchronous belt to move to drive the bracket 201 to move. The optical axis is matched in the axial hole 2011 and is used to guide the movement of the bracket 201.

[0046] Before the 3D printer 300 starts printing, the transfer device 302 drives the nozzle assembly 202 to move toward the printing platform 301 through the bracket 201. When the nozzle assembly 202 abuts the printing platform 301, the nozzle assembly 202 is subject to slight resistance. At this time, the end of the strain sensor 100 connected to the nozzle assembly 202 is subjected to force, and the end of the strain sensor 100 connected to the bracket 201 is fixed. In this way, the strain sensor 100 is deformed. After the strain sensor 100 is deformed, it can generate corresponding detection information (for example, current changes, resistance changes or voltage changes are detected), thereby triggering detection. Therefore, the current position information of the print head 200 can be detected by the strain sensor 100, so as to facilitate the leveling of the printing platform 301 (for example, the height error of the printing platform 301 can be automatically compensated by software during the actual printing process. The specific compensation algorithm of the software can be based on a known compensation algorithm, which will not be repeated here).

[0047] In the present embodiment, the nozzle assembly 202 abutting against the printing platform 301 means that the nozzle assembly 202 just touches the printing platform 301, rather than squeezing the printing platform 301, and the printing platform 301 does not undergo obvious deformation due to the contact of the nozzle assembly 202; it is understandable that at this time, the printing platform 301 undergoes microscopic deformation, and it can be considered that the printing platform 301 hardly moves in the vertical direction. In this way, after the nozzle assembly 202 abuts against the printing platform 301, there is no need to additionally calculate the displacement of the printing platform 301, and the height value of the contact position between the printing platform 301 and the nozzle assembly 202 can be obtained based on the obtained position of the nozzle assembly 202.

[0048] See also Figures 5 to 7 The strain sensor 100 includes an elastic connector 10 and a detection member 20. The fixing portion 12 is connected to the bracket 201, and the connecting portion 11 is connected to the nozzle assembly 202. A first groove 13 is formed on opposite sides of the middle of the connecting portion 11 and is concave inwardly along the width direction Y2 of the elastic connector 10. The first groove 13 is used to enhance the elastic deformation ability of the connecting portion 11. The detection member 20 is attached to the middle of one side surface of the connecting portion 11, and its edge does not exceed the edge of the first groove 13. The detection member 20 is used to detect the deformation generated by the elastic connector 10. The elastic connector 10 is also provided with an enlarged hole 14 between the detection member 20 and the fixing portion 12.

[0049] By providing a first concave groove 13 on both sides of the connecting portion 11 along the width direction Y2 of the elastic connecting member 10, the width of the connecting portion 11 at the first groove 13 is made smaller. When the nozzle assembly 202 abuts against the printing platform 301, the connecting portion 11 is subjected to the force from the printing platform 301, and the fixing portion 12 remains fixed. The connecting portion 11 is more likely to bend at a position with a smaller width, i.e., where the first groove 13 is provided, thereby driving the detection member 20 at the first groove 13 to deform, thereby ensuring that the detection member 20 can detect the deformation of the connecting portion 11 at this location. The force required for the elastic connecting member 10 with the first groove 13 to deform is smaller than the force required for the elastic connecting member 10 without the first groove 13 to produce the same deformation. In this way, the detection sensitivity of the strain sensor 100 can be improved. Similarly, after the enlarged hole 14 is provided between the detection member 20 and the fixing portion 12, since the elastic connecting member 10 is hollowed out at this position, the deformation of the connecting member 11 after being subjected to the same force is larger than that of the elastic connecting member 10 without the enlarged hole 14. Therefore, the enlarged hole 14 can also achieve the purpose of increasing the deformation of the elastic connecting member 10. In addition, the provision of the two first grooves 13 and the enlarged hole 14 makes it much more likely that the portion of the connecting member 11 between the first groove 13 and the enlarged hole 14 will deform when the connecting member 11 is subjected to force than the portion between the enlarged hole 14 and the fixing portion 12. This greatly increases the detection of the connecting member 11 by the detection member 20 when it is deformed, thereby improving the detection sensitivity of the strain sensor 100.

[0050] In summary, since the strain sensor 100 of this embodiment is provided with the first groove 13 and the enlarged hole 14, after the connecting portion 11 is subjected to the same force, the elastic connector 10 of this embodiment produces a larger deformation than the elastic connector 10 without the first groove 13 and the enlarged hole 14. When the nozzle assembly 202 slightly contacts the printing platform 301, the strain sensor 100 can generate a trigger signal, thereby greatly improving the detection sensitivity and detection accuracy of the contact between the nozzle assembly 202 and the printing platform 301. In addition, since there is no need for the nozzle assembly 202 to apply an excessive force to the printing platform 301, the deformation amount of the printing platform 301 during the leveling process can also be reduced, which can not only reduce the possibility of deformation of the printing platform 301 and improve the protection of the printing platform 301, but also because the error caused by the deformation of the printing platform 301 is reduced, the leveling accuracy of the printing platform 301 can be further improved.

[0051] In this embodiment, the elastic connector 10 is a square elastic sheet, and the connecting portion 11 and the fixing portion 12 are two opposite ends of the square sheet. Optionally, in this embodiment, the elastic connector 10 can be specifically set as a spring steel plate. In other embodiments, the fixing portion 12 can also be located in the middle of the square sheet. In addition, the shape of the elastic connector 10 can also be formed into other shapes such as a runway shape, an ellipse, etc.

[0052] In this embodiment, see Figure 6 , the distance between the first groove 13 and the connecting portion 11 is L1, the distance between the first groove 13 and the fixing portion 12 is L2, and L2 / L1 is between 4 and 7. L2 / L1 can be specifically set to any one of 4, 4.1, 4.5, 4.9, 5, 5.1, 5.5, 5.9, 6, 6.1, 6.5, 6.9 and 7. In other embodiments, the value of L2 / L1 can also be adjusted according to actual strain detection requirements.

[0053] When the value of L2 / L1 is low, the force required for the elastic connector 10 to deform will be greater. When the value of L2 / L1 is high, the elastic connector 10 is easily deformed under the weight of the nozzle assembly 202, affecting subsequent detection. Therefore, in this embodiment, by setting L2 / L1 between 4 and 7, it can be ensured that the elastic connector 10 only needs a small force to deform, and the elastic connector 10 can be prevented from failing under the weight of the nozzle assembly 202. Specifically, L2 / L1 can be set to one or more of 4, 4.5, 5, 5.5, 6, 6.5, 7, etc.

[0054] In this embodiment, see Figure 5 The enlarged hole 14 is located between the first groove 13 and the fixing portion 12 along the length direction Y1 of the elastic connector 10, and the enlarged hole 14 is located between the two first grooves 13 along the width direction Y2 of the elastic connector 10. The projection of one side of the enlarged hole 14 on the detection member 20 is located at the edge of the detection member 20, so that the detection member 20 can be completely attached to the elastic connector 10, reducing the possibility of the detection member 20 being separated from the elastic connector 10 when being bent.

[0055] Alternatively, see Figure 5 The enlarged hole 14 is roughly triangular in shape, with one vertex of the triangle being arranged toward the fixing portion 12, and the other two vertexes being arranged toward both sides of the width direction Y2 of the elastic connector 10. In this way, the size of the enlarged hole 14 is increased in the direction close to the connecting portion 11, which can further improve the elastic deformation capacity of the elastic connector 10.

[0056] See also Figure 6In this embodiment, the connecting portion 11 is provided with a second groove 15 which is concave toward the fixing portion 12. The second groove 15 is used to guide the elastic connecting member 10 to deform at the second groove 15 when it bends from one side to the other side in the width direction Y2. Since the surface flatness of the printing platform 301 is not clear, during the process of the nozzle assembly 202 abutting the printing platform 301, there is a possibility that the elastic connecting member 10 bends from one side to the other side in the width direction Y2 after the nozzle assembly 202 abuts the printing platform 301. After the second groove 15 is provided on the connecting portion 11, in the above case, the deformation amount generated by the elastic connecting member 10 at the second groove 15 is larger, which can also improve the detection sensitivity of the strain sensor 100 and the protection effect on the printing platform 301.

[0057] In addition, the second groove 15 , the enlarged hole 14 and the two first grooves 13 together define an area, which greatly increases the possibility of deformation of the connecting portion 11 in the area when a force is applied, thereby improving the detection sensitivity of the strain sensor 100 .

[0058] In this embodiment, see Figure 7 , the second groove 15 is formed by being recessed inwardly from the middle of the edge of one side of the connecting part 11 away from the fixing part 12 along the length direction Y1 of the elastic connecting member 10. The depth and width of the inward recess of the second groove 15 are greater than the depth and width of the inward recess of the first groove 13. The second groove 15 divides the connecting part 11 into two connecting blocks 111 spaced apart along the width direction Y2 of the elastic connecting member 10. The two connecting blocks 111 are respectively provided with two first connecting holes 112. The groove surface of the second groove 15 is also provided with a protruding support portion 16, and the support portion 16 is used to support the detection member 20 installed on the second surface 18. Specifically, the part of the detection member 20 extending into the second groove 15 is attached to the surface of the support portion 16. The support portion 16 and the enlarged hole 14 are both located in the middle of the length direction Y1 of the elastic connecting member 10, and the two are spaced apart. In other embodiments, depending on the size and shape of the detection member 20, it is also possible not to additionally provide the support portion 16.

[0059] In this embodiment, see Figure 2 The elastic connector 10 has two oppositely disposed first surfaces 17 and second surfaces 18, the adapter 203 is disposed on the first surface 17, and the detection member 20 is disposed on the second surface 18. In this way, the gap between the elastic connector 10 and the heat dissipation fins 2023 can be fully utilized to install the detection member 20.

[0060] In this embodiment, see Figure 6The two first grooves 13 are symmetrically arranged along the width direction Y2 of the elastic connector 10, and the two first grooves 13 are symmetrical about the first symmetry axis O1, and the first symmetry axis O1 is parallel to the length direction Y1 of the elastic connector 10. In this way, the positions of the two first grooves 13 in the length direction Y1 of the elastic connector 10 are fixed, and when the connecting portion 11 is subjected to force and the fixing portion 12 is fixed, the elastic connector 10 can be deformed at the fixed position in the length direction Y1 thereof (i.e., the position where the first grooves 13 are located).

[0061] In this embodiment, see Figure 6 The detection member 20 includes a strain gauge 21, and the strain gauge 21 includes a first portion 211 and a second portion 212. The first portion 211 and the second portion 212 are symmetrical about a second symmetric axis O2, and the second symmetric axis O2 is parallel to the width direction Y2 of the elastic connector 10 and is located between two oppositely disposed groove sides of the first groove 13. In this way, when the elastic connector 10 is deformed at the first groove 13, the strain gauge 21 is deformed at the second symmetric axis O2, so as to limit the deformation position of the strain gauge 21 when the connecting portion 11 is subjected to force, thereby improving the detection sensitivity of the strain sensor 100.

[0062] In this embodiment, see Figure 6 The outer edge of the first part 211 is arc-shaped, and the outer edge of the second part 212 is arc-shaped. In this way, when the first part 211 and the second part 212 are bent along the second symmetry axis O2, the deformation amount of the strain gauge 21 as a whole is the largest, so that a more obvious detection signal can be generated, thereby improving the detection accuracy of the strain sensor 100.

[0063] Also, see Figure 7 A portion of the outer edge of the first portion 211 coincides with the edge of the portion of the support portion 16 that extends outward, a portion of the outer edge of the second portion 212 coincides with the hole surface of the enlarged hole 14 on the side close to the support portion 16, an outer edge of a connection between the first portion 211 and the second portion 212 on one side coincides with the bottom surface of a first groove 13, and an outer edge of a connection between the first portion 211 and the second portion 212 on the other side coincides with the bottom surface of another first groove 13. In this way, the detection member 20 is roughly arranged in the area surrounded by the second groove 15, the enlarged hole 14 and the two first grooves 13 to ensure that the detection member 20 can detect deformation generated at any position in the area, thereby further improving the detection reliability of the strain sensor 100.

[0064] The detection member 20 is fully supported and the strength of the detection member 20 is not negatively affected by the enlarged hole 14 , thereby ensuring the elastic deformation capability of the elastic connecting member 10 and improving the deformation sensitivity of the strain sensor 100 .

[0065] Specifically, the shape of the strain gauge 21 can be set to be circular, in which case the second symmetry axis O2 is a diameter of the circle, or the shape of the strain gauge 21 can be set to be elliptical, in which case the second symmetry axis O2 corresponds to the major axis of the ellipse. In other embodiments, the shape of the strain gauge 21 can also be adjusted according to actual needs, which will not be described in detail here.

[0066] In this embodiment, see Figure 6 The detection member 20 further includes a signal transmission unit 22, which is disposed on the strain gauge 21 and is used to transmit a signal (such as a current change signal, a voltage change signal, or a resistance change signal, etc.) generated when the strain gauge 21 is deformed.

[0067] Alternatively, see Figure 5 The strain gauge 21 is a voltage ceramic strain gauge, which has two stacked sheets, and two signal transmission parts 22, one signal transmission part 22 is connected to one sheet, and the other signal transmission part 22 is connected to the other sheet. When the strain gauge 21 is bent, the voltage between the two sheets changes, thereby realizing strain detection. In this embodiment, the edges of the two sheets are concentric circles, and the edge of one sheet is located inside the edge of the other sheet. In other embodiments, the strain gauge 21 can also form a structure for detecting strain through resistance changes and voltage changes.

[0068] In this embodiment, refer to Figures 2 to 4 The print head 200 further includes an adapter 203, one end of which is connected to the connection portion 11, and the other end is connected to the nozzle assembly 202. Through the arrangement of the adapter 203, the strain sensor 100 can be installed at different positions of the nozzle assembly 202 according to actual needs, so as to utilize the space of the nozzle assembly 202 and reduce the overall volume of the print head 200.

[0069] In this embodiment, see Figure 6 The two first connection holes 112 are respectively connected to the adapter 203 through fastening structures such as bolts or pins.

[0070] In this embodiment, see Figure 6 The fixing portion 12 is provided with a plurality of second connection holes 121, and the plurality of second connection holes 121 are respectively connected to the bracket 201 through fastening structures such as bolts or pins.

[0071] Specifically, see Figure 2The nozzle assembly 202 includes a heat sink 2021, which includes a heat sink 2022 and a plurality of heat sink fins 2023. The heat sink 2022 is provided with a plurality of heat sink fins 2023 on both sides of the length direction Y1 of the elastic connector 10. An escape space Q is provided above the side of the heat sink 2022 facing the strain connector. The adapter 203 is provided in the escape space Q and connected to the heat sink 2022. The connecting portion 11 is attached to the bottom surface of the adapter 203 and connected to the heat sink 2021. The elastic connector 10 is provided between the adapter 203 and the heat sink fins 2023. In this way, the utilization of the heat sink 2021 can be improved, and the related structures of the nozzle assembly 202 for conveying consumables will not be affected, thereby reducing the overall volume of the print head 200.

[0072] Of course, in other embodiments, according to actual needs, the adapter 203 can also be installed at different positions of the nozzle assembly 202, and when the installation position changes, the connecting portion 11 of the elastic connecting member 10 can also be directly connected to the nozzle assembly 202, which is not limited here.

[0073] Alternatively, see Figure 2 The nozzle assembly 202 further includes a nozzle 2026 and a throat 2025. The nozzle 2026 is connected to the heat sink 2021. One end of the throat 2025 passes through the heat sink 2021 and is connected to the nozzle 2026. The other end of the throat 2025 is connected to the extrusion mechanism. The throat 2025 is used to transport the consumables extruded by the extrusion mechanism to the nozzle 2026. The nozzle 2026 is used to eject the consumables to the printing platform 301. When the nozzle assembly 202 abuts against the printing platform 301, the nozzle 2026 abuts against the printing platform 301.

[0074] The above implementation modes are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred implementation modes, a person skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A strain sensor, characterized in that: include: An elastic connector, the elastic connector having a connecting portion and a fixing portion spaced apart along its length direction, and first grooves are formed on opposite sides of a middle portion of the connecting portion and inwardly concave along the width direction of the elastic connector, the first grooves being used to enhance the elastic deformation capacity of the connecting portion; A detection member, the detection member is attached to the middle of one side surface of the connecting portion, and the detection member is used to detect the deformation of the elastic connecting member; The elastic connecting member is further provided with an enlarged hole between the detecting member and the fixing portion.

2. The strain sensor according to claim 1, characterized in that: The two first grooves are symmetrically arranged along the width direction of the elastic connecting member, the two first grooves are symmetrical about the first symmetry axis, and the edge of the detection member does not exceed the edge of the first groove.

3. The strain sensor according to claim 2, characterized in that: The detection member includes a strain gauge, which includes a first part and a second part. The first part and the second part are symmetrical about a second symmetry axis. The second symmetry axis is parallel to the width direction of the elastic connecting member and is located between two oppositely arranged groove sides of the first groove.

4. The strain sensor according to claim 1, characterized in that: The connecting portion is provided with a second groove, which is formed inwardly from the middle of the edge of one side of the connecting portion away from the fixing portion along the length direction of the elastic connecting member. The second groove is used to guide the elastic connecting member to deform at the second groove when it bends from one side to the other side in its width direction.

5. The strain sensor according to claim 4, characterized in that: The groove surface of the second groove is also provided with a protruding support portion, and a part of the detection member is attached to the support portion.

6. The strain sensor according to claim 1, characterized in that: The distance between the first groove and the connecting portion is L1, the distance between the first groove and the fixing portion is L2, and L2 / L1 is between 4 and 7.

7. A print head for extruding consumables on a printing platform, characterized in that: The print head comprises: A bracket, the bracket being used to connect the transfer device; A nozzle assembly, the nozzle assembly is used to extrude consumables; The strain sensor according to any one of claims 1 to 6, wherein a fixed portion of the strain sensor is connected to the bracket, a connecting portion of the strain sensor is connected to the nozzle assembly, and the strain sensor is used to be triggered when the nozzle assembly abuts against the printing platform.

8. The print head according to claim 7, characterized in that: The print head also includes a transfer component, one end of which is connected to the connection portion, and the other end of which is connected to the nozzle assembly.

9. The print head according to claim 8, characterized in that: The nozzle assembly includes a heat sink, a side surface of the adapter abuts against and is connected to the heat sink, and the connecting portion is attached to the bottom surface of the adapter and is connected to the heat sink.

10. A 3D printer, characterized in that: include: Printing platform; A print head as claimed in any one of claims 7 to 9; The transfer device is connected to the print head and is used to drive the print head to move relative to the printing platform.

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