Anti-freeze safety device for fused deposition modeling 3d printing apparatus

Abstract

The application discloses a kind of anti-freezing safety device for fused deposition modeling 3d printing device, it is characterized in that, anti-freezing safety device includes the elastic bag of fixed setting in the lower end of cooling water tank outside and with cooling water tank inside communication, lower clamping plate is horizontally arranged in the lower end of elastic bag, upper clamping plate is horizontally arranged in the upper end of elastic bag, the upper surface of lower clamping plate and the lower surface of upper clamping plate have a pair of oppositely arranged contact, contact is connected to the control circuit of circulating pump, upper clamping plate is also connected and arranged with upper clamping plate lifting control device above it.The application can avoid that circulating pump is forced to start when cooling water freezes, causes burnout damage.

Description

[0001] The present application is a divisional application of patent application No. 202210435187.2, filed on April 24, 2022, entitled "3D printing device for fused deposition modeling". TECHNICAL FIELD

[0002] The present application relates to the field of additive manufacturing 3D printing technology, in particular to an anti-freezing safety device for a 3D printing device for fused deposition modeling. BACKGROUND

[0003] 3D printing (3D Printing) is a kind of rapid prototyping technology, also known as additive manufacturing; it is a technology that uses laser, hot melt nozzle and other ways to stack and bond materials such as plastic, metal and ceramic powder layer by layer to construct objects based on digital models. In recent years, 3D printing technology has been widely used in industrial design, jewelry, automobiles, aerospace, dental and medical industries, education and many other fields. Currently, there are many types of 3D printers, such as selective laser melting SLM, selective laser sintering SLS, three-dimensional powder bonding, fused deposition modeling FDM, etc.

[0004] Fused Deposition Modeling (FDM) is also known as Fused Filament Fabrication. This process is to extrude a filament of material such as thermoplastic, wax or metal from a heated nozzle according to the predetermined trajectory of each layer of the part at a fixed rate to deposit the melt.

[0005] The conventional fused deposition modeling 3D printer currently has a structure including a base, a printing platform installed in the middle of the base, support frames vertically installed on the base on both sides of the printing platform, a vertical telescopic mechanism provided on the support frames, a printing nozzle, and a horizontal moving device for installing the printing nozzle on the vertical telescopic mechanism. During printing, the printing nozzle is controlled by the vertical telescopic mechanism to move vertically for layer-by-layer printing, and the printing nozzle is controlled by the horizontal moving device to move along the printing path of each layer to complete printing.

[0006] This conventional structure has the following defects: 1. The position of the nozzle. If the heating temperature is not high, the melting effect of the filament material is not good, and the printing forming quality is not good. If the heating temperature is too high, the internal temperature of the rear end of the nozzle will be too high, which will easily damage the internal structure of the nozzle. 2. The model product formed by printing is bonded to the workbench, and often needs to be separated with a knife, which is troublesome to take the model. SUMMARY

[0007] In view of the above problems of the prior art, the technical problem to be solved by the present application is how to provide a fused deposition modeling 3D printing device capable of better controlling the printing temperature to improve the printing quality and further facilitating the taking of the printed product. A freeze-proof safety device for the fused deposition modeling 3D printing device is also provided, which can prevent the circulating pump from being forced to start and being burnt out when the cooling water freezes.

[0008] In order to solve the above technical problems, the present application adopts the following technical scheme:

[0009] The fused deposition modeling 3D printing device comprises a base, a printing platform installed in the middle of the base, support frames vertically installed on the base on both sides of the printing platform, a vertical telescopic mechanism arranged on the support frames, a printing nozzle and a feeding device, the printing nozzle being installed on the vertical telescopic mechanism through a horizontal moving device, and the feeding device being installed on the support frame and connected with the printing nozzle.

[0010] In this way, when the printing nozzle works, the electric heating device heats the nozzle position alone, so that the printing filament sent to the position is melted and sprayed, and at the same time, the circulating cooling water pipeline is pumped to continuously cool the nozzle body by the water cooling structure, so that the internal temperature is kept at a low state and is not affected by the high temperature of the nozzle position, thereby improving the protection effect of the feeding structure inside the nozzle body. In this way, the nozzle position can have sufficient high temperature to ensure the melting effect of the printing filament and the printing precision while ensuring safety. In implementation, the vertical telescopic mechanism and the horizontal moving device are both mature prior art, and a screw nut mechanism is usually used to realize the moving control in three directions, and the specific structure is not described here.

[0011] Further, the water cooling structure is a cooling water pipe spirally wound outside the nozzle body, or a water cooling interlayer integrally arranged outside the nozzle body.

[0012] In this way, the structure is simple and convenient to set.

[0013] Further, the cooling water tank is installed and fixed on the top plate at the upper end of the support frame. In this way, the installation and fixation and water supply are facilitated.

[0014] Further, the anti-freezing safety device is arranged, which comprises an elastic bag fixedly arranged at the lower end outside the cooling water tank and communicated with the inside of the cooling water tank, a lower clamping plate horizontally arranged at the lower end of the elastic bag, an upper clamping plate horizontally arranged at the upper end of the elastic bag, a pair of oppositely arranged contacts arranged on the upper surface of the lower clamping plate and the lower surface of the upper clamping plate, and the contacts are connected to the control circuit of the circulating pump, and an upper clamping plate lifting control device is further arranged above the upper clamping plate.

[0015] In this way, when the circulating cooling system works, the upper clamping plate lifting control device is first opened to control the downward movement of the upper clamping plate. When the cooling water in the elastic bag is in a liquid state, the upper clamping plate lifting control device can control the downward movement of the upper clamping plate and extrude the elastic bag to make the contacts connected. At this time, the control circuit of the circulating pump can be connected and opened to start the circulating cooling system. When the cooling water freezes, the frozen elastic bag can block the upper clamping plate. At this time, the control circuit of the circulating pump will not be connected, avoiding the forced start of the circulating pump to cause damage.

[0016] The reason for adopting the above anti-freezing safety device is that antifreeze is usually added to the cooling water for anti-freezing treatment, but the cooling water will still freeze in extremely cold weather. Because the antifreeze is added to the cooling water, the freezing temperature is unstable, so it is difficult to judge whether it is frozen by temperature detection. At the same time, because the cooling water tank is located at a high position and is in a closed state, it is troublesome to manually open the cooling water tank to check whether it is frozen. Moreover, the cooling water tank is usually frozen from the top, and the water pipe and the circulating pump are arranged at the lower end of the cooling water tank. Therefore, as long as the lower part of the cooling water tank is not frozen, it can still work and the frozen water will gradually melt with the backflow of the cooling water. Therefore, manual checking also has the problem of inaccurate checking. Therefore, the applicant designs the above anti-freezing safety device based on the physical principle as a safety switch of the circulating pump, so that as long as the lower part of the cooling water tank is not frozen, the circulating pump can be started to work, but once the lower end of the cooling water tank is frozen, the elastic bag is frozen, and the contacts between the upper and lower clamping plates cannot be connected, and the circulating pump cannot be started, which has the effect of flexible detection, convenience and forced safety.

[0017] Further, the upper clamping plate lifting control device is a telescopic electric cylinder, the telescopic arm of the telescopic electric cylinder is downwardly fixed with the upper clamping plate, the telescopic electric cylinder is installed and fixed on an electric cylinder support, and the electric cylinder support is installed on the top plate.

[0018] In this way, the structure is simple and convenient to implement. The structure equivalent to using the switch of the telescopic electric cylinder instead of the switch of the circulating pump realizes the detection and control of whether the bottom of the water tank is frozen by relying on the anti-freezing safety device, which greatly improves the safety control effect of the circulating pump.

[0019] Further, the upper clamp plate comprises two horizontally opposite half-clamp plates, one of which is located above the elastic bag, and the other of which has a contact head on its lower surface. The two half-clamp plates are respectively hinged at one end to a vertically arranged clamp plate mounting block, which is fixed to the lower end of the telescopic arm of the upper clamp plate lifting control device. The clamp plate mounting block has a vertically arranged sliding groove in the middle, and a sliding block is arranged in the sliding groove. Each of the two half-clamp plates is respectively hinged to a symmetrical connecting rod, and the upper ends of the two connecting rods are commonly hinged to the outer end of the sliding block protruding out of the sliding groove. A retaining spring is further arranged between the two half-clamp plates and the clamp plate mounting block, which keeps the half-clamp plates in a horizontal state when they are not subjected to external force, and at this time the sliding block is located at the lower end of the sliding groove.

[0020] In this way, the retaining force of the retaining spring on the half-clamp plates in the horizontal state can be adjusted to be greater than the elastic force required for the extrusion deformation of the elastic bag, so that when the cooling water in the elastic bag is in a liquid state, the upper clamp plate can normally descend and make the contact head connected. When the cooling water in the elastic bag is in a frozen solid state, the elastic bag can block the half-clamp plates during the descending process of the telescopic arm of the upper clamp plate lifting control device, and overcome the retaining force of the retaining spring, so that the outer ends of the two half-clamp plates are opened upward under the linkage action of the sliding block, and the contact head is not connected, but the normal operation of the upper clamp plate lifting control device is not affected. When the cooling water in the elastic bag is frozen, the motor of the upper clamp plate lifting control device is prevented from being damaged due to forced output power caused by the inability of the upper clamp plate to descend.

[0021] Further, the printing platform comprises a table box mounted on the base, and the upper end of the table box has a plurality of parallel arranged hollow grooves, and a plurality of plug blocks corresponding to the hollow grooves are arranged in the hollow grooves and can slide up and down. The upper end of the plug block is flush with the upper surface of the table box at the starting position, and the lower end of the plug block is fixed to a horizontally arranged supporting plate inside the table box, and the lower end of the supporting plate is provided with a supporting plate lifting control device.

[0022] In this way, after printing is completed, the supporting plate can be controlled to be pushed out upward by the supporting plate lifting control device, so that the printed product is separated from the upper surface of the table box, and the printed product can be conveniently taken off, solving the defect that the product formed by melting is difficult to take off from the printing platform.

[0023] Further, the supporting plate lifting control device comprises a lifting pipe vertically fixed in the middle of the lower surface of the supporting plate, a sleeve is sleeved on the lifting pipe, the outer side of the sleeve is fixed in the table box through a horizontal support plate, the sleeve and the lifting pipe are vertically arranged and are in vertical sliding fit through the stop rotation concave-convex structure, a rotating column is arranged in the lifting pipe in fit, the rotating column is rotatably installed in the table box, the rotating column is connected with the transmission mechanism and the power device, the inner side wall of the lifting pipe is provided with a lifting control slide, the outer side of the rotating column is fixedly provided with a lifting control convex, the lifting control convex is in sliding fit in the lifting control slide, the lifting control slide comprises a first slide part, a second slide part, a third slide part and a fourth slide part which are circumferentially connected with each other, the first slide part is horizontally arranged, one end of the second slide part is connected with the first slide part, and the other end is arranged in an upward slope, one end of the third slide part is connected with the upper end of the second slide part, and the other end is arranged in a downward slope and the lower end exceeds the height of the first slide part, one end of the fourth slide part is connected with the lower end of the third slide part, and the other end is connected with the starting end of the first slide part in an upward slope.

[0024] In this way, when the lifting control convex is located in the first slide part, the upper surface of the plug-in block is flush with the upper surface of the table box, and the table surface is used as a workbench to print and form products, after printing, the rotating column is controlled to rotate, the lifting control convex slides from the first slide part to the second slide part, the lifting pipe goes down and drives the plug-in block to move downward to forcibly separate from the products, then the lifting control convex slides into the third slide part, the lifting pipe goes up and drives the plug-in block to move upward and lift the products upward to separate from the surface of the table box, then the lifting control convex slides into the fourth slide part and returns to the first slide part from the fourth slide part, the lifting pipe goes down and drives the plug-in block to reset downward, and thus one cycle is completed by rotating one circle. The existence of the horizontal first slide part leaves a certain amount of reset, which guarantees the reset effect. Therefore, by controlling the rotating column to rotate one circle, the lifting control of the supporting plate is completed, that is, the supporting plate is first lowered, then raised, and then lowered again, and the products and the surface of the workbench are completely separated. The supporting plate lifting control device has the advantages of simple structure, convenient implementation and reliable control.

[0025] Further, the transmission mechanism comprises a driven gear installed on the rotating column and a driving gear engaged with the driven gear, the driving gear is fixed on a vertically arranged driving gear shaft, a worm wheel is fixedly installed on the driving gear shaft, the worm wheel is engaged with a horizontally arranged worm, and the outer end of the worm extends out of the table box and is provided with a rotating handle.

[0026] In this way, the rotating handle can be conveniently rotated by hand to achieve control. The structure is simple and the control is convenient. Of course, in implementation, the rotating column can also be connected with a motor to achieve electric control.

[0027] In summary, the supporting plate lifting control device has the advantages of better control of the printing temperature to improve the printing quality and convenient separation and taking of the printed products from the printing platform. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The structural schematic diagram for the embodiment of the present application.

[0029] Figure 2 The structural schematic diagram for the embodiment of the present application. Figure 1 The structural schematic diagram for the embodiment of the present application.

[0030] Figure 3 The structural schematic diagram for the embodiment of the present application. Figure 1 The structural schematic diagram for the embodiment of the present application.

[0031] Figure 4 The structural schematic diagram for the embodiment of the present application. Figure 3 The top view.

[0032] Figure 5 The structural schematic diagram for the embodiment of the present application. Figure 1 The structural schematic diagram for the embodiment of the present application. DETAILED DESCRIPTION

[0033] The present application will be further described in detail in combination with the specific embodiments.

[0034] DETAILED DESCRIPTION: Refer to Figures 1-5 A fused deposition modeling 3D printing device, comprising a base 1, a printing platform installed in the middle of the base 1, a support frame 3 vertically installed on the base on both sides of the printing platform, a vertical telescopic mechanism 4 provided on the support frame 3, a printing nozzle and a feeding device, the printing nozzle is installed on the vertical telescopic mechanism through a horizontal moving device 5, the feeding device (not shown in the figure) is installed on the support frame and connected with the printing nozzle; an electric heating device 6 is provided on the printing nozzle, wherein the printing nozzle comprises a nozzle body 7, a nozzle 8 is provided at the lower end of the nozzle body 7 and extends downward, the electric heating device 6 is installed on the nozzle 8, a water cooling structure 9 is further provided outside the nozzle body 7, the water cooling structure 9 is connected with a cooling water tank 11 through a flexible water pipe 10, a circulating pump is provided in the cooling water tank 11 (or on the cooling water pipe) to form a circulating cooling system.

[0035] In this way, when the printing nozzle works, the electric heating device heats the nozzle position alone, so that the printing filament sent to this position is melted and sprayed out for printing, at the same time, water is pumped by the circulating cooling water pipeline, so that the water cooling structure can continuously cool the nozzle body, ensure that the internal temperature is in a lower state, and is not affected by the high temperature of the nozzle position, improve the protection effect of the feeding structure inside the nozzle body. In this way, the nozzle position can have enough high temperature under the condition of ensuring safety, the melting effect of the printing filament is ensured, and the printing precision is ensured. In the implementation, the vertical telescopic mechanism and the horizontal moving device are both mature existing technologies, and a screw nut mechanism is usually used to realize the moving control in three directions, and the specific structure is not described here.

[0036] The water cooling structure 9 is a cooling water pipe spirally wound outside the nozzle body, or in other embodiments, a water cooling interlayer integrally arranged outside the nozzle body.

[0037] Thus, the structure is simple and convenient to set.

[0038] The cooling water tank 11 is fixedly installed on the top plate at the upper end of the support frame. Thus, the installation and water supply are facilitated.

[0039] The anti-freezing safety device is further provided, which comprises an elastic bag 12 fixedly arranged at the lower end outside the cooling water tank and connected to the inside of the cooling water tank. The lower end of the elastic bag is horizontally provided with a lower clamping plate 13, and the upper end of the elastic bag is horizontally provided with an upper clamping plate. The upper surface of the lower clamping plate 13 and the lower surface of the upper clamping plate are provided with a pair of oppositely arranged contacts 15 connected to the control circuit of the circulating pump. The upper clamping plate is further connected with an upper clamping plate lifting control device 16.

[0040] Thus, when the circulating cooling system is working, the upper clamping plate lifting control device is first started to control the downward movement of the upper clamping plate. When the cooling water in the elastic bag is in a liquid state, the upper clamping plate lifting control device can control the downward movement of the upper clamping plate and press the elastic bag to make the contacts connected. At this time, the control circuit of the circulating pump can be connected and started to make the circulating cooling system start working. When the cooling water is frozen, the frozen elastic bag can block the upper clamping plate. At this time, the control circuit of the circulating pump cannot be connected, avoiding the forced start of the circulating pump to cause damage.

[0041] The reason for using the above anti-freezing safety device is that antifreeze is usually added to the cooling water for anti-freezing treatment, but the cooling water can still freeze in extremely cold weather. Because the antifreeze is added to the cooling water, the freezing temperature is unstable, so it is difficult to determine whether it is frozen by temperature detection. At the same time, because the cooling water tank is located at a high position and is in a closed state, it is troublesome to manually open the cooling water tank to check whether it is frozen. Moreover, the cooling water tank is usually frozen from the top, and the water pipe and the circulating pump are arranged at the lower end of the cooling water tank. Therefore, as long as the lower part of the cooling water tank is not frozen, it can still work and the frozen water will gradually melt with the backflow of the cooling water. Therefore, manual checking also has the problem of inaccurate checking. Therefore, the applicant designs the above anti-freezing safety device based on the physical principle as a safety switch of the circulating pump, so that as long as the lower part of the cooling water tank is not frozen, the circulating pump can be started to work. However, once the lower end of the cooling water tank is frozen, the elastic bag is frozen, the contacts between the upper and lower clamping plates cannot be connected, and the circulating pump cannot be started. Thus, the effect of flexible detection and forced safety is achieved.

[0042] The upper clamping plate lifting control device 16 is a telescopic electric cylinder, the telescopic arm of the telescopic electric cylinder is downwardly fixed with the upper clamping plate, the telescopic electric cylinder is fixed on an electric cylinder support 17, and the electric cylinder support 17 is installed on the top plate.

[0043] Thus, the structure is simple and convenient to implement, the structure is equivalent to using the switch of the telescopic electric cylinder to replace the switch of the circulating pump, and the detection and control of whether the bottom of the water tank is frozen is realized by relying on the anti-freezing safety device, and the safety control effect on the circulating pump is greatly improved.

[0044] The upper clamping plate comprises two horizontally opposite half clamping plates 14, one of which is located above the elastic bag, and the other of which is provided with a contact 15 on the lower surface, and the two half clamping plates are respectively hinged at one end to a clamping plate mounting block 18 arranged vertically, the clamping plate mounting block 18 is fixed at the lower end of the telescopic arm of the upper clamping plate lifting control device, the clamping plate mounting block has a vertically arranged sliding groove 19 at the middle position, a sliding block is arranged in the sliding groove 19, and the two half clamping plates are respectively hinged with a symmetrical connecting rod 20, the upper ends of the two connecting rods 20 are commonly hinged to the outer end of the sliding block protruding from the sliding groove, and a retaining spring 21 is further arranged between the two half clamping plates 14 and the clamping plate mounting block 18, so that the half clamping plates are kept in a horizontal state when not subjected to external force, and at this time, the sliding block is located at the lower end of the sliding groove.

[0045] In this way, the retaining force of the retaining spring on the half clamping plate in the horizontal state can be adjusted to be greater than the elastic force required for the extrusion deformation of the elastic bag, so that when the cooling water in the elastic bag is a liquid, the upper clamping plate can normally descend and make the contact be connected. When the cooling water in the elastic bag is a frozen solid, the elastic bag can block the half clamping plate during the descending process of the telescopic arm of the upper clamping plate lifting control device, and overcome the retaining force of the retaining spring, so that the outer ends of the two half clamping plates are opened upward under the linkage action of the sliding block, and then the contact cannot be connected, but the normal work of the upper clamping plate lifting control device is not affected. When the cooling water in the elastic bag is frozen, the motor of the upper clamping plate lifting control device is prevented from being damaged due to forced output power caused by the inability of the upper clamping plate to descend.

[0046] The printing platform comprises a table box 2 installed on the base, the upper end of the table box 2 is provided with a plurality of parallel arranged air slots 29, and a slide block 22 capable of sliding up and down is arranged in each air slot 29, the upper end of the slide block 22 is flush with the upper surface of the table box 2 at the starting position, the lower end of the slide block 22 is fixed on a horizontally arranged supporting plate 23 in the table box 2, and the lower end of the supporting plate 23 is provided with a supporting plate lifting control device.

[0047] In this way, after printing is completed, the supporting plate can be controlled to be pushed out upward by the supporting plate lifting control device, so that the printed product is separated from the upper surface of the table box, the printed product is convenient to take off, and the defect that the product formed by melting is difficult to take off from the printing platform is solved.

[0048] The lifting control device comprises a lifting pipe 24 fixed vertically in the middle of the lower surface of the supporting plate, a sleeve 25 is sleeved on the lifting pipe 24, the outer side of the sleeve 25 is fixed in the table box 2 through a horizontal support plate 26, the sleeve 25 and the lifting pipe 24 are vertically arranged and are in vertical sliding fit through the stop rotation concave-convex structure, a rotating column 27 is arranged in the lifting pipe 24, the rotating column 27 is rotatably installed in the table box, the rotating column 27 is connected with the transmission mechanism and the power device, a lifting control slide is arranged on the inner side wall of the lifting pipe 24, a lifting control protrusion 28 is fixedly arranged on the outer side of the rotating column 27, the lifting control protrusion 28 is in sliding fit in the lifting control slide, the lifting control slide comprises a first slide part 31, a second slide part 32, a third slide part 33 and a fourth slide part 34 which are connected with each other in the circumferential direction of the sleeve, the first slide part 31 is horizontally arranged, one end of the second slide part 32 is connected with the first slide part, the other end of the second slide part 32 is arranged obliquely upward, one end of the third slide part 33 is connected with the upper end of the second slide part, the other end of the third slide part 33 is arranged obliquely downward and the lower end of the third slide part 33 is higher than the first slide part, one end of the fourth slide part 34 is connected with the lower end of the third slide part, the other end of the fourth slide part 34 is connected with the starting end of the first slide part.

[0049] In this way, when the lifting control protrusion is located in the first slide part, the upper surface of the insert block is flush with the upper surface of the table box, and the table box serves as a workbench for product printing and forming, after printing, the rotating column is controlled to rotate, the lifting control protrusion slides from the first slide part to the second slide part, the lifting pipe goes down and drives the insert block to move downward to forcibly separate from the product, then the lifting control protrusion slides into the third slide part, the lifting pipe goes up and drives the insert block to move upward and lift the product upward to separate from the surface of the table box, then the lifting control protrusion slides into the fourth slide part and returns to the first slide part from the fourth slide part, the lifting pipe goes down and drives the insert block to reset downward, and thus one cycle is completed by rotating one round. The existence of the horizontal first slide part leaves a certain amount of space for resetting, which ensures the resetting effect. Therefore, by controlling the rotating column to rotate one round, the lifting control of the supporting plate is completed, that is, the supporting plate is first lowered, then raised and then lowered again, and the product is completely separated from the surface of the workbench. The structure is simple, the implementation is convenient, and the control is reliable.

[0050] The transmission mechanism comprises a driven gear 35 installed on the rotating column 27 and a driving gear 36 engaged with the driven gear 35, the driving gear 36 is fixed on a vertically arranged driving gear shaft 37, a worm gear 38 is fixedly installed on the driving gear shaft, the worm gear is engaged with a horizontally arranged worm 39, and the outer end of the worm extends out of the table box and is provided with a rotating handle 40.

[0051] In this way, the rotating handle is manually rotated to realize the control, the structure is simple, and the control is convenient. Of course, the rotating column can also be connected with a motor to realize electric control.

Claims

1. A freeze protection safety device for a fused deposition modeling 3D printing device, characterized in that, The anti-freezing safety device comprises an elastic bag fixedly arranged at the lower end outside the cooling water tank and connected with the inside of the cooling water tank, a lower clamping plate horizontally arranged at the lower end of the elastic bag, an upper clamping plate horizontally arranged at the upper end of the elastic bag, a pair of oppositely arranged contacts arranged on the upper surface of the lower clamping plate and the lower surface of the upper clamping plate, and the contacts being connected to the control circuit of the circulating pump, and an upper clamping plate lifting control device arranged above the upper clamping plate.

2. The freeze protection insurance device for a fused deposition modeling 3D printing apparatus according to claim 1, wherein The upper clamping plate lifting control device is a telescopic electric cylinder, the telescopic arm of the telescopic electric cylinder is downwardly fixed with the upper clamping plate, the telescopic electric cylinder is fixedly arranged on an electric cylinder support, and the electric cylinder support is arranged on the top plate.

3. The freeze protection insurance device for a fused deposition modeling 3D printing apparatus according to claim 1, wherein The upper clamping plate comprises two horizontally oppositely arranged half clamping plates, one of the half clamping plates is arranged above the elastic bag, the other half clamping plate is provided with the contacts on the lower surface, the opposite ends of the two half clamping plates are respectively hingedly connected to a vertically arranged clamping plate mounting block, the clamping plate mounting block is fixedly arranged at the lower end of the telescopic arm of the upper clamping plate lifting control device, the clamping plate mounting block is provided with a vertically arranged sliding groove at the middle position, a sliding block is arranged in the sliding groove, the two half clamping plates are respectively hingedly connected to a pair of symmetrical connecting rods, the upper ends of the two connecting rods are commonly hingedly connected to the outer end of the sliding block protruding out of the sliding groove, a retaining spring is further arranged between the two half clamping plates and the clamping plate mounting block, and the retaining spring enables the half clamping plates to keep in the horizontal state when the half clamping plates are not subjected to external force and the sliding block is located at the lower end of the sliding groove.

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