3D printing equipment for engineering model

Abstract

The invention relates to the technical field of 3D printing, in particular to engineering model 3D printing equipment which comprises a supporting frame, a feeding device arranged on the outer side of the supporting frame, a printing assembly installed on the upper side of the interior of the supporting frame and a placing assembly installed on the inner side of the supporting frame. A magnetic hot plate assembly is arranged on the bottom plate; the magnetic hot plate assembly comprises a magnetic plate and a heating plate, the heating plate is arranged on the upper side of the bottom plate, and the magnetic plate is arranged on the upper side of the heating plate through a sliding assembly; the sliding assembly comprises a plurality of sealing strips, the plurality of sealing strips are fixedly connected to the bottom surface of the magnetic plate in parallel, and a plurality of sealed heating spaces are formed between every two adjacent sealing strips; and a shrinkage assembly is arranged in the sealed heating space. After printing is completed, a printed object can be separated by bending the magnetic plate, so that the magnetic plate does not need to be disassembled, and the printed object can be taken out conveniently.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to an engineering model 3D printing device. Background Art

[0002] 3D printing equipment uses computer-aided design software to convert digital models into physical models, and realizes rapid manufacturing of objects by stacking materials layer by layer. Engineering model 3D printing equipment has a wide range of applications in aerospace, transportation, electronic products, industrial design and other fields.

[0003] The patent with the publication number CN112959657B discloses a 3D printer, including a base frame, a plurality of vertical frames are arranged on the top of the base frame, a top frame is arranged between any two of the vertical frames, a crossbeam is arranged between the top frames through a Y-axis controller, and the printing device includes a booster, a raw material pipe is slidably connected inside the booster, a heating chamber is arranged at the bottom of the booster, a flow chamber is connected at the bottom of the heating chamber, and a temperature sensor is arranged inside the flow chamber to detect its internal temperature. The present invention controls the current value of the electromagnet to change the gap between the heat-resistant magnetic ball and the nozzle, so that the desired shape and volume are obtained after cooling, and the printing effect is good and the printing accuracy is high.

[0004] When current 3D printing equipment is printing, materials are generally stacked on the printing plate. However, it is difficult to remove the materials printed on the printing plate, so a magnetic hot plate is installed on the printing plate to facilitate material removal. However, when removing the materials from the magnetic hot plate, it is usually necessary to completely remove the magnetic hot plate and then bend it to separate the printed object from the magnetic hot plate. This method cannot separate large-volume printed objects, making it difficult to remove the materials and reducing the speed of removing the materials. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art that large-volume printed objects cannot be separated, which makes it difficult to retrieve materials and reduces the speed of retrieval, and to propose an engineering model 3D printing device.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: An engineering model 3D printing device, comprising: a support frame, a feeding device arranged outside the support frame, a printing assembly installed on the upper side of the support frame, and a placement assembly installed inside the support frame, wherein the placement assembly comprises a bottom plate, and a magnetic hot plate assembly is arranged on the bottom plate; The magnetic hot plate assembly comprises a magnetic plate and a heating plate, wherein the heating plate is arranged on the upper side of the bottom plate, and the magnetic plate is arranged on the upper side of the heating plate through a sliding assembly; The sliding assembly comprises a plurality of sealing strips, which are fixedly connected in parallel to the bottom surface of the magnetic plate, and a plurality of sealed heating spaces are formed between two adjacent sealing strips; A shrinking assembly is provided inside the sealed heating space, and the shrinking assembly is used to pull two adjacent sealing strips closer together, driving the magnetic plate to bend upward. The shrinking assembly includes two connecting tubes and an energized solenoid. The two connecting tubes are respectively fixedly connected to the sides of the two sealing strips close to each other, and the energized solenoid is fixedly connected between the two connecting tubes.

[0007] Preferably, the placement assembly also includes a drive motor, a drive rod and a bracket, the drive motor is fixedly mounted on the inner bottom of the support frame, the drive rod is fixedly connected to the output end of the drive motor, the bracket is mounted on the drive rod, the drive rod is used to drive the bracket to move up and down, and the base plate is fixedly connected to the bracket.

[0008] Preferably, the printing assembly includes a driving slide, a heating module and a nozzle end, the driving slide is fixedly mounted on the upper end of the inner part of the support frame, the heating module is slidably disposed on the driving slide, and the nozzle end is fixedly connected below the heating module.

[0009] Preferably, the sliding assembly includes multiple slide rails and multiple sliders, the multiple slide rails are fixedly connected to the heating plate in parallel, the multiple sealing strips are arranged perpendicular to the slide rails, the multiple sliders are fixedly connected to the multiple sealing strips, and are slidably arranged inside the multiple slide rails respectively.

[0010] Preferably, the portion of the sealing strip located between the two slide rails protrudes outward, and a sealed heating space is formed between two adjacent slide rails and two adjacent sealing strips, and a plurality of the sealed heating spaces are distributed in a matrix between the magnetic plate and the heating plate.

[0011] Preferably, the upper end of the sealing strip is fixedly connected to the magnetic plate, and the upper end is elastically arranged to be used for deformation and stretching of the magnetic plate.

[0012] Preferably, an energizing component is provided below the middle of the sliding component, and the energizing component is used to limit the position of the sliding component on the heating plate and energize the energizing solenoid at the same time.

[0013] Preferably, the power-on component includes a limit seat, an insert block and a rotating handle, the limit seat is fixedly connected to the middle of the sealing strip in the middle of the sliding component, a connecting port is opened in the middle of the bottom plate and the heating plate, the insert block is slidably arranged inside the connecting port, and the rotating handle is fixedly connected to the side of the insert block.

[0014] Preferably, an elastic strip is provided between the two connecting tubes, and the elastic strip is fixedly connected to the upper sides of the two connecting tubes to limit the distance between the two connecting tubes.

[0015] Preferably, the elastic strip is made of an elastic material and has a semicircular cross section. A heat conduction port is provided in the middle of the elastic strip, and when bent upward, the cross section is V-shaped.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. After printing is completed, power is supplied to the inside of the energized solenoid, and the energized solenoid is contracted by a strong current, so that the sealing strip is pulled by the energized solenoid, and the sealing strip is pulled closer, and the sealing strip pulls and bends the magnetic plate, and a tensile force is generated between the deformed magnetic plate and the shaped printed object, so that the magnetic plate is separated from the printed object, and it is convenient to quickly separate the printed object from the magnetic plate. After printing is completed, the present invention can separate the printed object by bending the magnetic plate, so that the magnetic plate does not need to be disassembled, which facilitates the removal of the printed object; 2. The magnetic plate has a certain elasticity, and the thickness of the part of the magnetic plate that needs to be bent is thinner than the part that is fixedly connected to the sealing strip. Under normal circumstances, the magnetic plate is supported and shaped by multiple sealing strips, so that the magnetic plate has sufficient support strength to support the printed object, which meets the overall deformation and support requirements of the magnetic plate; 3. The original magnetic hot plate directly transfers heat to the magnetic plate, which will cause rapid heat loss and consume more energy. Through high-temperature resistant sealing strips and slide rails, multiple sealed heating spaces are formed between the magnetic plate and the heating plate. The sealed heating space is used to store heat, reduce heat loss, and thus reduce energy consumption; 4. The energized solenoid generates heat, which increases the temperature inside the sealed heating space and heats the part where the printed object and the magnetic plate are stuck together, so that the contact part melts, making it easier to separate the printed object from the magnetic plate during the subsequent folding and bending of the magnetic plate. 5. During the contraction of the energized solenoid, the magnetic plate will bend, causing the shape of the magnetic plate to change. In order to avoid the irregular contraction of the magnetic plate causing a large change in position, the center position of the magnetic plate is fixed by the energized component, so that during the contraction of the magnetic plate, the magnetic plates on both sides begin to contract toward the middle, thereby ensuring that the printed object above the magnetic plate will not tilt significantly and ensuring the stability of the printed object; 6. When the energized solenoid is energized, it contracts, thereby driving the connecting tubes on both sides to approach each other. In the process of the connecting tubes approaching each other, the elastic strip will bend upward. In the process of the elastic strip bending, the bent magnetic plate can be supported, thereby strengthening the bending of the magnetic plate and ensuring the separation between the magnetic plate and the printed object. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a front structural schematic diagram of an engineering model 3D printing device proposed by the present invention; Figure 2 This is a schematic diagram of the back structure of an engineering model 3D printing device proposed by the present invention; Figure 3 A schematic diagram of the support frame structure of an engineering model 3D printing device proposed by the present invention; Figure 4 A schematic diagram of the front structure of a magnetic hot plate assembly of an engineering model 3D printing device proposed by the present invention; Figure 5 A bottom schematic diagram of the unfolded structure of a magnetic hot plate assembly of an engineering model 3D printing device proposed by the present invention; Figure 6 A front schematic diagram of the unfolded structure of a magnetic hot plate assembly of an engineering model 3D printing device proposed by the present invention; Figure 7 A schematic cross-sectional structure diagram of a magnetic hot plate assembly of an engineering model 3D printing device proposed by the present invention; Figure 8 A schematic diagram of the structure of a sliding component of an engineering model 3D printing device proposed by the present invention; Fig. 9 A schematic diagram of the sealing strip structure of an engineering model 3D printing device proposed by the present invention; Fig.10 A schematic diagram of the shrinkage component structure of an engineering model 3D printing device proposed by the present invention; Fig.11 This is a state change diagram of an engineering model 3D printing device proposed by the present invention after power is turned on.

[0018] In the figure: 1. Support frame; 2. Feeding device; 3. Printing assembly; 31. Driving slide; 32. Heating module; 33. Nozzle end; 4. Placement assembly; 41. Bottom plate; 42. Driving motor; 43. Driving rod; 44. Bracket; 5. Magnetic hot plate assembly; 51. Magnetic plate; 52. Heating plate; 6. Sliding assembly; 61. Sealing strip; 62. Slide rail; 63. Slider; 7. Contraction assembly; 71. Connecting pipe; 72. Power-on solenoid; 8. Power-on assembly; 81. Limit seat; 82. Insert block; 83. Turning handle; 9. Elastic strip. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0020] The terms such as "upper", "lower", "left", "right", "middle" and "one" used in the present invention are only for the convenience of description and are not used to limit the scope of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of the present invention without substantially changing the technical content.

[0021] Reference Figure 1-Figure 11 , an engineering model 3D printing device, comprising: a support frame 1, a feeding device 2 arranged outside the support frame 1, a printing component 3 installed on the upper side of the support frame 1, and a placement component 4 installed inside the support frame 1, wherein the placement component 4 comprises a bottom plate 41, and a magnetic hot plate component 5 is arranged on the bottom plate 41; The magnetic hot plate assembly 5 includes a magnetic plate 51 and a heating plate 52, wherein the heating plate 52 is arranged on the upper side of the bottom plate 41, and the magnetic plate 51 is arranged on the upper side of the heating plate 52 through a sliding assembly 6; The sliding assembly 6 includes a plurality of sealing strips 61, and the plurality of sealing strips 61 are fixedly connected in parallel to the bottom surface of the magnetic plate 51, and a plurality of sealed heating spaces are formed between two adjacent sealing strips 61; A shrinking assembly 7 is provided inside the sealed heating space, and the shrinking assembly 7 is used to pull two adjacent sealing strips 61 closer together, driving the magnetic plate 51 to bend upward. The shrinking assembly 7 includes two connecting tubes 71 and an energized solenoid 72. The two connecting tubes 71 are respectively fixedly connected to the sides of the two sealing strips 61 that are close to each other, and the energized solenoid 72 is fixedly connected between the two connecting tubes 71.

[0022] In an embodiment of the application of the above technical solution, printing and stacking are performed on the surface of the magnetic plate 51 through the printing component 3. After printing is completed, power is supplied to the inside of the energized solenoid, and the energized solenoid 72 is contracted by the strong current, thereby pulling the sealing strip 61 through the energized solenoid 72 to bring the sealing strip 61 closer. The sealing strip 61 pulls and bends the magnetic plate 51, and a pulling force is generated between the deformed magnetic plate 51 and the shaped printed object, thereby separating the magnetic plate 51 from the printed object, making it convenient to quickly separate the printed object from the magnetic plate 51.

[0023] The process of magnetic hot plate adsorbing plastic materials mainly depends on the magnetism of the magnetic hot plate surface and certain characteristics of the plastic material, such as containing magnetizable components or undergoing special treatment. Special types of plastics, such as plastic composite materials containing iron powder or other magnetic substances, may have certain magnetism or be magnetizable. When subjected to the magnetic force of the magnetic hot plate, they can be adsorbed on the surface of the hot plate, thereby achieving a stable printing process.

[0024] The present invention can separate the printed objects by bending the magnetic plate 51 after printing is completed, thereby eliminating the need to disassemble the magnetic plate 51 and facilitating the removal of the printed objects.

[0025] The preferred technical solution in this embodiment is: Reference Figure 3 The placement component 4 also includes a driving motor 42, a driving rod 43 and a bracket 44. The driving motor 42 is fixedly installed at the inner bottom of the support frame 1, the driving rod 43 is fixedly connected to the output end of the driving motor 42, and the bracket 44 is installed on the driving rod 43. The driving rod 43 is used to drive the bracket 44 to move up and down, and the bottom plate 41 is fixedly connected to the bracket 44.

[0026] When performing 3D printing, the driving motor 42 is controlled to drive the driving rod 43 to rotate. Since the bracket 44 is spirally connected to the driving rod 43, as the driving rod 43 rotates, the bracket 44 will rotate along the thread on the driving rod 43, thereby driving the bracket 44 to cooperate with the printing component 3 to move up and down, facilitating rapid 3D printing.

[0027] Reference Figure 3 The printing component 3 includes a driving slide 31, a heating module 32 and a nozzle end 33. The driving slide 31 is fixedly installed on the upper end of the supporting frame 1, the heating module 32 is slidably set on the driving slide 31, and the nozzle end 33 is fixedly connected below the heating module 32.

[0028] When the 3D printing device is working, the feeding device 2 introduces the raw material into the heating module 32 , melts the material through the heating module 32 , and then stacks it on the magnetic hot plate assembly 5 through the nozzle end 33 .

[0029] Reference Figure 5-9 The sliding assembly 6 further includes a plurality of slide rails 62 and a plurality of sliders 63. The plurality of slide rails 62 are fixedly connected to the heating plate 52 in parallel. The plurality of sealing strips 61 are vertically arranged with the slide rails 62. The plurality of sliders 63 are fixedly connected to the plurality of sealing strips 61 and are slidably arranged inside the plurality of slide rails 62 respectively. The portion of the sealing strip 61 between the two slide rails 62 protrudes outward, and a sealed heating space is formed between two adjacent slide rails 62 and two adjacent sealing strips 61. A plurality of the sealed heating spaces are distributed in a matrix between the magnetic plate 51 and the heating plate 52. The upper end of the sealing strip 61 is fixedly connected to the magnetic plate 51 , and the upper end is elastically arranged to be used for deformation and stretching of the magnetic plate 51 .

[0030] During the installation of the magnetic plate 51 and the heating plate 52 , the sliders 63 are slid into the interior of the plurality of slide rails 62 to allow for quick installation and removal of the magnetic plate 51 and to facilitate cleaning of debris remaining on the surface of the magnetic plate 51 .

[0031] In order to ensure the bending of the magnetic plate 51, the magnetic plate 51 has a certain elasticity, and the thickness of the part of the magnetic plate 51 that needs to be bent is thinner than the part fixedly connected to the sealing strip 61. Under normal circumstances, the magnetic plate 51 is supported and shaped by multiple sealing strips 61, so that the magnetic plate 51 has sufficient supporting strength to support the printed object, which meets the overall deformation and support requirements of the magnetic plate 51. When the magnetic plate 51 is pulled and begins to bend upward, the elastic connection between the sealing strip 61 and the magnetic plate 51 provides a certain extension space for the magnetic plate 51 when bending.

[0032] Since the magnetic plate 51 needs to be heated by the heating plate 52, the magnetic hot plate can heat the printing area quickly and evenly. This heating effect helps to control the melting and solidification process of the printing material and improve the printing quality and accuracy; The original magnetic hot plate directly transfers heat to the magnetic plate 51, which will cause rapid heat loss and consume more energy. Through the high temperature resistant sealing strip 61 and the slide rail 62, multiple sealed heating spaces are formed between the magnetic plate 51 and the heating plate 52. The sealed heating space is used to store heat, reduce heat loss, and thus reduce energy consumption. After printing is completed, since the bottom of the printed object has been adhered to the magnetic plate 51, in order to ensure that the printed object can be quickly separated from the magnetic plate 51, the energized solenoid 72 is energized to generate heat, thereby increasing the temperature inside the sealed heating space, and heating the portion where the printed object and the magnetic plate 51 are adhered, so that the contact portion melts, thereby facilitating the separation of the printed object and the magnetic plate 51 during the subsequent folding and bending of the magnetic plate 51.

[0033] Reference Figure 7-9 , an energizing component 8 is provided at the lower middle part of the sliding component 6, and the energizing component 8 is used to limit the position of the sliding component 6 on the heating plate 52 and energize the energizing solenoid 72 at the same time; The power-on component 8 includes a limit seat 81, an insert block 82 and a rotating handle 83. The limit seat 81 is fixedly connected to the middle of the sealing strip 61 in the middle of the sliding component 6. A connecting port is opened in the middle of the bottom plate 41 and the heating plate 52. The insert block 82 is slidably arranged inside the connecting port. The rotating handle 83 is fixedly connected to the side of the insert block 82.

[0034] When the magnetic plate 51 and the heating plate 52 are installed, in order to ensure that the magnetic plate 51 and the heating plate 52 are effectively fixed and connected, the limit seat 81 is moved to the installation port position of the heating plate 52, and the plug block 82 is driven upward by operating the rotating handle 83 on the outside. By rotating the plug block 82, the plug block 82 is spirally connected to the limit seat 81. At the same time, the plug block 82 is connected to the circuit inside the limit seat 81, so as to energize multiple energized solenoids 72.

[0035] During the contraction of the energized solenoid 72, the magnetic plate 51 will bend, thereby causing the shape of the magnetic plate 51 to change. In order to prevent the magnetic plate 51 from contracting irregularly and causing a large change in position, the center of the magnetic plate 51 is fixed at this position through the energized component 8. As a result, during the contraction of the magnetic plate 51, the magnetic plates 51 on both sides begin to contract toward the middle, thereby ensuring that the printed object above the magnetic plate 51 will not tilt significantly, thereby ensuring the stability of the printed object.

[0036] Reference Figure 9-11 An elastic strip 9 is provided between the two connecting tubes 71, and the elastic strip 9 is fixedly connected to the upper sides of the two connecting tubes 71 to limit the distance between the two connecting tubes 71; The elastic strip 9 is made of elastic material and has a semicircular cross section. A heat conduction port is provided in the middle of the elastic strip 9 , and when bent upward, the cross section is V-shaped.

[0037] The two connecting tubes 71 are fixedly connected by an elastic member, and the energized solenoid 72 is protected at the same time to prevent the internal energized solenoid 72 from being squeezed when the printed object on the magnetic plate 51 is pressed down, thereby ensuring the normal use of the energized solenoid.

[0038] When the energized solenoid 72 is energized, it contracts, thereby driving the connecting tubes 71 on both sides to approach each other. In the process of the connecting tubes 71 approaching each other, the elastic strip 9 will bend upward. In the process of the elastic strip 9 bending, the bent magnetic plate 51 can be supported, thereby strengthening the bending of the magnetic plate 51 and ensuring the separation between the magnetic plate 51 and the printed object.

[0039] At the same time, the heat conducting opening on the elastic strip 9 can ensure the normal conduction of the heat generated by the energized solenoid 72 .

[0040] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An engineering model 3D printing device, comprising: A support frame (1), a feeding device (2) arranged outside the support frame (1), a printing assembly (3) installed on the upper side of the support frame (1), and a placement assembly (4) installed on the inner side of the support frame (1), characterized in that the placement assembly (4) comprises a bottom plate (41), and a magnetic hot plate assembly (5) is arranged on the bottom plate (41); The magnetic hot plate assembly (5) comprises a magnetic plate (51) and a heating plate (52), wherein the heating plate (52) is arranged on the upper side of the bottom plate (41), and the magnetic plate (51) is arranged on the upper side of the heating plate (52) via a sliding assembly (6); The sliding assembly (6) comprises a plurality of sealing strips (61), wherein the plurality of sealing strips (61) are fixedly connected in parallel to the bottom surface of the magnetic plate (51), and a plurality of sealed heating spaces are formed between two adjacent sealing strips (61); A shrinking assembly (7) is provided inside the sealed heating space. The shrinking assembly (7) is used to pull two adjacent sealing strips (61) closer together, thereby driving the magnetic plate (51) to bend upward. The shrinking assembly (7) comprises two connecting tubes (71) and an energized solenoid (72). The two connecting tubes (71) are respectively fixedly connected to the sides of the two sealing strips (61) that are close to each other, and the energized solenoid (72) is fixedly connected between the two connecting tubes (71).

2. The engineering model 3D printing device according to claim 1, characterized in that: The placement assembly (4) further comprises a driving motor (42), a driving rod (43) and a bracket (44); the driving motor (42) is fixedly mounted on the inner bottom of the support frame (1); the driving rod (43) is fixedly connected to the output end of the driving motor (42); the bracket (44) is mounted on the driving rod (43); the driving rod (43) is used to drive the bracket (44) to move up and down; and the bottom plate (41) is fixedly connected to the bracket (44).

3. The engineering model 3D printing device according to claim 1, characterized in that: The printing assembly (3) comprises a driving carriage (31), a heating module (32) and a nozzle end (33); the driving carriage (31) is fixedly mounted on the upper end of the support frame (1); the heating module (32) is slidably mounted on the driving carriage (31); and the nozzle end (33) is fixedly connected below the heating module (32).

4. The engineering model 3D printing device according to claim 1, characterized in that: The sliding assembly (6) further comprises a plurality of sliding rails (62) and a plurality of sliding blocks (63); the plurality of sliding rails (62) are fixedly connected in parallel to the heating plate (52); the plurality of sealing strips (61) are arranged perpendicular to the sliding rails (62); and the plurality of sliding blocks (63) are fixedly connected to the plurality of sealing strips (61) and are respectively slidably arranged inside the plurality of sliding rails (62).

5. The engineering model 3D printing device according to claim 4, characterized in that: The portion of the sealing strip (61) located between the two slide rails (62) protrudes outwards, and a sealed heating space is formed between two adjacent slide rails (62) and two adjacent sealing strips (61), and a plurality of the sealed heating spaces are distributed in a matrix between the magnetic plate (51) and the heating plate (52).

6. The engineering model 3D printing device according to claim 1, characterized in that: The upper end of the sealing strip (61) is fixedly connected to the magnetic plate (51), and the upper end is elastically arranged to be used for deformation and stretching of the magnetic plate (51).

7. The engineering model 3D printing device according to claim 1, characterized in that: An energizing component (8) is provided below the middle of the sliding component (6), and the energizing component (8) is used to limit the position of the sliding component (6) on the heating plate (52) and energize the energizing solenoid (72) at the same time.

8. The engineering model 3D printing device according to claim 7, characterized in that: The power supply component (8) comprises a limit seat (81), an insert block (82) and a rotating handle (83); the limit seat (81) is fixedly connected to the middle of a sealing strip (61) in the middle of the sliding component (6); a connecting port is provided in the middle of the bottom plate (41) and the heating plate (52); the insert block (82) is slidably arranged inside the connecting port; and the rotating handle (83) is fixedly connected to a side of the insert block (82).

9. The engineering model 3D printing device according to claim 1, characterized in that: An elastic strip (9) is provided between the two connecting tubes (71); the elastic strip (9) is fixedly connected to the upper sides of the two connecting tubes (71) and is used to limit the distance between the two connecting tubes (71).

10. The engineering model 3D printing device according to claim 9, characterized in that: The elastic strip (9) is made of an elastic material and has a semicircular cross section. A heat conduction opening is provided in the middle of the elastic strip (9), and when bent upward, the cross section is V-shaped.

Images