Anti-winding wire box of FDM printer and residual wire detection method of anti-winding wire box

Abstract

The invention provides an anti-winding wire box of an FDM printer. The anti-winding wire box comprises a wire box shell, and the outer end of the wire box shell is rotationally connected with a wire box cover; the power interface and the main control module are both installed on the outer side face of the wire shell. A wire channel, a positioning roller group and a tray mounting column are sequentially arranged in the wire box shell; wherein a damper is placed in the charging tray mounting column to provide rotation resistance; the positioning roller group comprises an upper positioning roller and a lower positioning roller which are arranged up and down; a charging tray is mounted on the charging tray mounting column; an electric heating net is arranged below the lower positioning roller; a fan is arranged on the lower portion of the electric heating net, a drying agent installation frame is arranged on the right portion of the fan, and the electric heating net, the fan and the drying agent installation frame are all located in an air circulation channel on the lower portion of the wire box. The device can prevent the wires from being excessively released, dry air can circulate in the device, and the residual amount of the wires is monitored in real time.

Description

Technical Field

[0001] The invention belongs to the field of fiber reinforced composite material FDM printer material wire storage equipment, and in particular relates to an FDM printer anti-winding wire box and a residual wire detection method thereof. Background Art

[0002] The fused deposition modeling 3D printer is a type of 3D printer that uses heat conduction to soften the filament, extrude it, and then deposit it. Prepreg filaments are the most common raw materials used. Usually, the prepreg filaments are prepared and formed before being wound on a filament reel. The mass of each reel of filament is generally 1 to 2 kg. During use, the filament is first unwound from the state originally wound on the material reel roller, and then driven by the printer extruder stepper motor to enter the heating area, and finally softened and deposited. For the filaments of fiber-reinforced resin-based composite materials, since the tree matrix itself has a certain degree of hygroscopicity, after moisture enters the filament, it will vaporize in the extruded melt due to the increase in temperature during the printing process, forming printing defects. Therefore, certain moisture-proof treatment is required during the storage of the filament.

[0003] The filament box is a tool for temporarily storing filament reels. Its working principle is to place the unsealed filament reels connected to the printer inside the box. The filament reels can rotate inside to complete the unwinding of the filaments. The unwinding filaments are output through the opening in the box wall and connected to the extruder. Usually, a heating unit is built in to heat the stored filaments to prevent the filaments from getting damp.

[0004] However, the existing filament boxes on the market usually have the problem of being unable to control the moderate unwinding of the filaments when facing filaments with high elasticity such as short fiber reinforced PEEK composite materials. This will cause the unwinding speed of the filament to be usually greater than the consumption speed of the printer during the actual printing process, and the excessive unwinding of the filament will accumulate as the printing progresses, and eventually the excessively unwound filament will be entangled on the material tray. At this time, the pulling of the filament by the extruder will cause the filament to bend at a certain position. As the pulling force increases, the radius of curvature increases. After reaching the maximum value that the filament can withstand, the filament will undergo irreversible deformation or breakage, seriously affecting the continuous operation of the printing. In addition, a section of the filament released from the filament box is connected to the extruder of the FDM printer. At this time, it is inevitable that the released filament will be returned to the filament box due to the movement of the nozzle, increasing the risk of filament entanglement and affecting the continuous and stable operation of the printer. In addition, the existing filament box cannot accurately detect the remaining filament content in the filament box, resulting in the possibility that the printing process may be forced to stop due to insufficient remaining filament. Summary of the invention

[0005] To solve the above problems, the present invention discloses an anti-winding wire box for an FDM printer and a residual wire detection method thereof, which ensures that the wire winding will not be entangled, and the residual wire content in the wire box can be accurately detected to improve efficiency.

[0006] An anti-winding wire box for an FDM printer comprises a wire box shell, wherein one side of the front end of the wire box shell is rotatably connected to a wire box cover; a power interface and a main control module are both mounted on the outer side of the wire box shell; a wire channel, a positioning roller group and a material tray mounting column are sequentially arranged in the wire box shell; a circulating air duct support is arranged below the material tray mounting column; a damper is placed at the end of the material tray mounting column to provide rotation resistance; the positioning roller group comprises an upper positioning roller and a lower positioning roller arranged at the upper and lower parts; the material tray is mounted on the material tray mounting column; the upper part of the rotating ring air duct support is open and the gap between the support and the wire box shell forms an air circulation channel; a fan and a desiccant mounting frame are sequentially arranged at the air inlet end of the circulating air duct support; an electric heating net is arranged at the bottom of the circulating air duct support.

[0007] Furthermore, the temperature sensor inside the wire box is located at the top of the inner cavity of the wire box housing.

[0008] Furthermore, both the upper positioning roller and the lower positioning roller are one-way rollers, and a spring is installed on the mounting shaft of the upper positioning roller to control the adaptive upward and downward movement of the upper positioning roller.

[0009] Furthermore, the wire box cover is connected to the wire box housing by a hinge, and the switch of the wire box can be controlled by rotation; and a handle is provided on the wire box cover.

[0010] Furthermore, the left end of the tray mounting column is sleeved on the protruding part of the right end of the damper to realize the installation of the tray mounting column and the damper; the left end of the damper is connected to the L-shaped mounting bracket, and is connected to the upper end of the force sensor through the lower end of the L-shaped mounting bracket, and the lower end of the force sensor is connected to the upper end of another L-shaped mounting bracket, and is connected to the wire box housing through the left end of the L-shaped mounting bracket. The damper provides rotational damping for the tray mounting column, and the force sensor can detect the mass located on the tray mounting column.

[0011] A method for detecting the remaining wire in an anti-winding wire box of an FDM printer can control the operation of an internal electric heating network to control the temperature inside the wire box through PID regulation of a main control module; the main control module controls the wire release speed of a wire disc in the wire box by controlling the resistance in a damper to prevent winding; and the main control module calculates the amount of remaining wire in the wire by detecting data returned from a force sensor.

[0012] Further, the specific contents are as follows:

[0013] m 盘 : The mass of the empty tray; m丝 : The mass of the wound wire when the reel is fully wound; m: The sum of the mass of the wire and the reel; m 余丝 : the mass of the remaining wire; ρ: the density of the wire; R 外 : The outer radius of the material tray, which is also the radius of the remaining wire after the material tray is fully wound with wire; R 内 : Inner radius of the tray; R 余丝 : The radius of the outer surface of the wire when the remaining wire is wound on the material disc; h: the thickness of the material disc; A: defined as the ratio of the volume of the wire after winding to the actual volume of the wire; M: the torque of the wire; M d : damping wheel torque; F: wire tension; π: pi; g: gravitational acceleration; V 绕 : The volume of the wire that can be wound on the tray; V 丝 : The actual volume of the wire after winding around the entire wire coil; V 盘余 : The winding volume of the remaining wire; V 余丝实 : The actual volume of the remaining wire; F: The force when the wire pulls the tray to rotate;

[0014] First, enter the following in the wire and control module: 盘 、m 丝 ,ρ,R 外 , R 内 , h, F; A is calculated using the built-in formula; the specific calculation is as follows:

[0015] R 外 2 *π*h–R 内 2 *π*h=V 绕

[0016] m 丝 / ρ 丝 =V 丝

[0017] Then: A=V 绕 / V 丝

[0018] The mechanical sensor can detect the real-time value of the sum of the mass of the material tray and the remaining wire material, and convert it into force N through an electrical signal;

[0019] N=m*g

[0020] m=m 盘 +m 余丝

[0021] According to the density calculation formula:

[0022] V 余丝实 =(mm 盘 ) / ρ

[0023] Combining the coefficient A, we get:

[0024] V 盘余 =A*V 余丝实

[0025] but

[0026] R 余丝 2 *π*h–R 内 2 *π*h=V 盘余

[0027] The solution is:

[0028]

[0029] The torque balance equation is established based on the method of balancing the roller damping torque by the product of the force and torque of the wire on the roller.

[0030] The wire moment is:

[0031] M=F*R 余丝

[0032] The moment balance equation is:

[0033] M d =M

[0034] The solution is:

[0035]

[0036] Set F in the control module. When the remaining wire content changes, the remaining wire mass is converted into the torque R of the wire acting on the roller through the above formula. Establish the required damping torque M of the roller d A linear function of the measured data N of the mechanical sensor is used to achieve real-time adjustment of the roller damping to ensure that the wire will not be over-released during the untangling process;

[0037] The calculation method of wire excess percentage is as follows:

[0038] Depend on

[0039] m=N / g

[0040] m=m 盘 +m 余丝

[0041] have to

[0042] m 余丝 =N / gm 盘

[0043] but

[0044] Remaining silk percentage = (m丝 / m 余丝 )*100%

[0045] Solved

[0046] Remaining silk percentage = {m 丝 / (N / gm 盘 )*100%

[0047] It can be seen from this that a functional relationship between N and the percentage of remaining wire material is established, and the amount of remaining wire material can be detected by detecting the value of N.

[0048] The present invention facilitates the installation of wires, and the wires can be drawn out of the wire material box through the distance between the two rollers. The electric heating network can realize air circulation inside the wire box in the power-on state. A high-temperature resistant desiccant is placed on a desiccant mounting rack to dry the air passing around it. The power interface increases the required power supply for the wire box, and the main control module controls the temperature control inside the wire box and the adjustment of the damping size of the damper. The electric heating network, the fan, and the desiccant mounting rack are all located in the air circulation channel at the lower part of the wire box. When the fan and the heating grid are working, the air at the upper part of the wire box enters the wire circulation and is first dried at the desiccant mounting rack, and then is heated to a specified temperature by the heating grid and blown to the upper wire, thereby realizing the drying and heating of the wire placed in the wire box. The temperature measuring device inside the wire box is located at the top of the wire box, and then the operation of the heating grid inside the wire box is controlled by PID regulation to achieve the internal temperature of the wire box maintained at the set temperature.

[0049] Beneficial results of the present invention:

[0050] 1. The device of the present invention can prevent excessive wire feeding, internally circulate dry air, and monitor the remaining wire amount in real time. The function of preventing excessive wire feeding is realized based on an adjustable damper and a mechanical one-way roller of the wire outlet channel; the internally circulated dry air is realized by a fan, a heating net, a desiccant mounting rack, and a temperature measuring device; the real-time detection of the remaining wire amount is realized by monitoring the force of the material tray on the wire column through a force sensor built into the material tray mounting column.

[0051] 2. Compared with the existing FDM printer filament box, the filament box of the present invention first obtains the remaining amount of the remaining filament through a measuring device, and converts it into an electrical signal for adjusting the damping size in the electromagnetic damper, so that the resistance of the material tray during the rotating discharge process is adapted to the curvature radius of the filament, thereby preventing the filament from breaking due to excessive curvature radius and resistance during the discharge process.

[0052] 3. Since a set of one-way rollers are set at the outlet of the filament box, the filament released from the filament box will not be entangled back into the filament box due to the external force generated by the movement of the nozzle, preventing the filament box inside the material tray from being entangled due to the movement of the nozzle. Secondly, the filament box has a built-in force sensor to detect the amount of filament remaining in the material box, preventing the printing from being interrupted due to insufficient remaining filament during a single printing process.

[0053] 4. Finally, an air duct is set at the bottom of the wire box, and an electric heating net, a fan and a desiccant mounting frame are set inside the air duct. The high-temperature resistant desiccant is installed therein. The desiccant is a high-temperature silica gel desiccant and can generally be used below 200 degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 , the wire box assembly of the present invention Figure 1 ;

[0055] Figure 2 , the wire box assembly of the present invention Figure 2 ;

[0056] Figure 3 , a cross-sectional view of the mounting structure of the tray mounting column;

[0057] Figure 4 , a control circuit diagram of the wire box of the present invention;

[0058] Figure 5 , schematic diagram of wire material calculation;

[0059] Figure 6 , a partial enlarged view of the cooperation between the spring and the upper positioning roller.

[0060] List of reference numerals:

[0061] Wherein: 1-wire box housing, 2-wire channel, 3-upper positioning roller, 4-lower positioning roller, 5-main control module, 6 electric heating net, 7 desiccant mounting bracket, 8-fan, 9-handle, 10-wire box cover, 11-internal air flow channel of the wire box, 12 tray mounting column, 13 tray, 14 force sensor, 15 wire, 16-damper, 17-temperature sensor, 18-mounting bracket; 19-roller moving track; 20-circulating air duct support; 21-spring. DETAILED DESCRIPTION

[0062] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0063] The present invention is a method for detecting residual wire in an anti-winding wire box of an FDM printer, and the specific structure is as follows: Figure 1-3 1 is the shell of the wire box, which can be used with the wire box cover 10 (after the cover is closed) to isolate the inside of the wire box from the outside. The wire box cover 10 is connected to the wire box shell 1 through a hinge, and the switch of the wire box can be controlled by rotation;

[0064] 2 is a wire channel, through which the wire is passed out from the inside of the wire box; 3 and 4 are upper positioning rollers and lower positioning rollers, which provide positioning for the wire, and the positioning rollers are one-way rollers to ensure that the wire 15 in the wire box will not return to the wire box under the action of external force after leaving the wire box through the wire channel 2; 5 is a main control module, which is responsible for controlling the operation of the fan 8, electric heating network 8, and damper 14 inside the wire; 6 is an electric heating network, which provides a higher temperature inside the wire, and the electric heating network is equipped with a temperature detection device for temperature measurement; 7 is a desiccant mounting bracket, which provides a position for placing desiccant inside the wire box; 8 is a fan, which provides circulating airflow between the wire and the inside; 9 is a handle, which is connected to the wire box cover 10 to facilitate opening the wire box, and 11 is an air flow channel inside the wire box, which is the wire box. In the air circulation channel inside the material box, the low-temperature and high-humidity air flow moves along the internal air flow channel 11 of the wire box through the action of the fan 8. When it moves to the desiccant mounting rack 7, the humidity in the air flow is reduced under the action of the desiccant, and then moves to the electric heating net 6, where the low-temperature air flow is heated and finally blown into the wire box; 12 is a material tray mounting column, on which the material tray 13 is mounted. A damper 16 is built into the column to provide rotational resistance to prevent the material tray 13 mounted on the material tray mounting column 12 from being entangled during the process of placing the wire 15; 13 is a material tray, on which the wire 15 is wound, and can be disassembled and assembled on the material tray column 12; 14 is a force sensor, which connects the material tray mounting column 12 and the wire box housing 1, and calculates the remaining wire 15 on the material tray 13 by detecting the force on the material tray mounting column 12.

[0065] like Figure 3 As shown, the left end of the tray mounting column 12 is sleeved on the protruding part of the right end of the damper 14 to realize the installation of the tray mounting column 12 and the damper 14; the left end of the damper 14 is connected to the L-shaped mounting bracket, and is connected to the upper end of the force sensor 14 through the lower end of the L-shaped mounting bracket, and the lower end of the force sensor 14 is connected to the upper end of another L-shaped mounting bracket, and is connected to the wire box housing through the left end of the L-shaped mounting bracket. The damper provides rotational damping for the tray mounting column, and the force sensor can detect the mass located on the tray mounting column. The damper provides rotational damping for the tray mounting column, and the force sensor can detect the mass located on the tray mounting column.

[0066] like Figure 6As shown in the figure, the upper positioning roller 3 is installed. One end of the upper positioning roller 3 is located in the roller moving track 19 and is connected to the lower end of the spring 21, and the upper end of the spring 21 is connected to the inner wall of the upper end of the roller moving track 19. In this mechanism, the roller can move upward under the action of an upward external force to compress the spring, and the wire can pass through the gap between the upper and lower positioning rollers.

[0067] like Figure 4 and 5 The figure shows the schematic diagram of the wire box control circuit. The wire box uses a DC power supply as the power supply, and the switch controls the presence or absence of current in the main control module; the PID regulation of the main control module can control the operation of the internal electric heating network to control the temperature inside the wire box; the main control module controls the wire release speed of the wire disc in the wire box by controlling the resistance in the damper to place the winding; the main control module calculates the amount of remaining wire in the wire by detecting the data returned by the force sensor.

[0068] m 盘 : The mass of the empty tray; m 丝 : The mass of the wound wire when the reel is fully wound; m: The sum of the mass of the wire and the reel; m 余丝 : the mass of the remaining wire; ρ: the density of the wire; R 外 : The outer radius of the material tray, which is also the radius of the remaining wire after the material tray is fully wound with wire; R 内 : Inner radius of the tray; R 余丝 : The radius of the outer surface of the wire when the remaining wire is wound on the material disc; h: the thickness of the material disc; A: defined as the ratio of the volume of the wire after winding to the actual volume of the wire; M: the torque of the wire; M d : damping wheel torque; F: wire tension; π: pi; g: gravitational acceleration; V 绕 : The volume of the wire that can be wound on the tray; V 丝 : The actual volume of the wire after winding around the entire wire coil; V 盘余 : The winding volume of the remaining wire; V 余丝实 : The actual volume of the remaining wire; F: The force when the wire pulls the tray to rotate;

[0069] First, enter the following in the wire and control module: 盘 、m 丝 ,ρ,R 外 , R 内 , h, F; A is calculated using the built-in formula; the specific calculation is as follows:

[0070] R 外 2 *π*h–R 内 2 *π*h=V 绕

[0071] m丝 / ρ 丝 =V 丝

[0072] Then: A=V 绕 / V 丝

[0073] The mechanical sensor can detect the real-time value of the sum of the mass of the material tray and the remaining wire material, and convert it into force N through an electrical signal;

[0074] N=m*g

[0075] m=m 盘 +m 余丝

[0076] According to the density calculation formula:

[0077] V 余丝实 =(mm 盘 ) / ρ

[0078] Combining the coefficient A, we get:

[0079] V 盘余 =A*V 余丝实

[0080] but

[0081] R 余丝 2 *π*h–R 内 2 *π*h=V 盘余

[0082] The solution is:

[0083]

[0084] The torque balance equation is established based on the method of balancing the roller damping torque by the product of the force and torque of the wire on the roller.

[0085] The wire moment is:

[0086] M=F*R 余丝

[0087] The moment balance equation is:

[0088] M d =M

[0089] The solution is:

[0090]

[0091] Set F in the control module. When the remaining wire content changes, the remaining wire mass is converted into the torque R of the wire acting on the roller through the above formula. Establish the required damping torque M of the roller d A linear function of the measured data N of the mechanical sensor is used to achieve real-time adjustment of the roller damping to ensure that the wire will not be over-released during the untangling process;

[0092] The calculation method of wire excess percentage is as follows:

[0093] Depend on

[0094] m=N / g

[0095] m=m 盘 +m 余丝

[0096] have to

[0097] m 余丝 =N / gm 盘

[0098] but

[0099] Remaining silk percentage = (m 丝 / m 余丝 )*100%

[0100] Solved

[0101] Remaining silk percentage = {m 丝 / (N / gm 盘 )}*100%

[0102] It can be seen from this that a functional relationship between N and the percentage of remaining wire material is established, and the amount of remaining wire material can be detected by detecting the value of N.

[0103] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above technical features.

Claims

1. An anti-winding filament box for an FDM printer, comprising a filament box housing (1), wherein one side of the front end of the filament box housing (1) is rotatably connected to a filament box cover (10); characterized in that: The power interface and the main control module (15) are both mounted on the outer side of the wire box housing (1); the wire box housing (1) is provided with a wire channel (2), a positioning roller group and a tray mounting column (12) in sequence; a circulating air duct support (20) is provided below the tray mounting column (12); a damper (14) is placed at the end of the tray mounting column (12) to provide rotation resistance; the positioning roller group comprises an upper positioning roller (3) and a lower positioning roller (4) arranged at the upper and lower parts; the tray (13) is mounted on the tray mounting column (12); the upper part of the rotating air duct support (20) is open and the gap between the rotating air duct support (20) and the wire box housing (1) forms an air circulation channel (11); a fan (8) and a desiccant mounting frame (7) are provided at the air inlet end of the circulating air duct support (20); an electric heating net (6) is provided at the bottom of the circulating air duct support (20).

2. The anti-winding wire box for FDM printer according to claim 1, characterized in that: The temperature sensor (17) inside the wire box is located at the top of the inner cavity of the wire box housing (1).

3. The anti-winding wire box for FDM printer according to claim 1, characterized in that: The upper positioning roller (3) and the lower positioning roller (4) are both one-way rollers. A spring is arranged on the mounting shaft of the upper positioning roller (3) to control the upper and lower adaptive movement of the upper positioning roller (3).

4. The anti-winding wire box for FDM printer according to claim 1, characterized in that: The wire box cover (10) is connected to the wire box housing (1) via a hinge, and the opening and closing of the wire box can be controlled by rotation; the wire box cover (10) is provided with a handle (9).

5. The anti-winding wire box for FDM printer according to claim 1, characterized in that: The left end of the tray mounting column (12) is sleeved on the protruding part of the right end of the damper (14), so as to realize the installation of the tray mounting column (12) and the damper (14); the left end of the damper (14) is connected to the L-shaped mounting bracket (18), and is connected to the upper end of the force sensor (14) through the lower end of the L-shaped mounting bracket; the lower end of the force sensor (14) is connected to the upper end of another L-shaped mounting bracket, and is connected to the wire box housing through the left end of the L-shaped mounting bracket.

6. A method for detecting residual wire in an anti-winding wire box of an FDM printer, characterized in that: The main control module pid regulation can control the operation of the internal electric heating network to control the temperature inside the wire box; the main control module controls the wire release speed of the wire disc in the wire box by controlling the resistance size in the damper to place the winding; The main control module calculates the amount of remaining wire in the wire by detecting the data returned by the force sensor.

7. The method for detecting residual wire of an anti-winding wire box of an FDM printer according to claim 6, characterized in that: The specific contents are as follows: m 盘 : The mass of the empty tray; m 丝 : The quality of the wire wound when the reel is full; m: the sum of the mass of the wire and the tray; m 余丝 : The quality of the remaining wire; ρ: density of wire; R 外 : The outer radius of the material tray, which is also the radius of the remaining wire after the material tray is fully wound with wire; R 内 : Inner radius of the tray; R 余丝 : The radius of the outer periphery of the remaining wire when it is wound on the material tray; h: disc thickness; A: defined as the ratio of the volume of the wire after winding to the actual volume of the wire; M: wire moment; M d : damping wheel torque; F: wire tension; π: pi; g: acceleration due to gravity; V 绕 : The volume of the wire that can be wound on the tray; V 丝 : The actual volume of the wire after winding around the entire wire coil; V 盘余 : The winding volume of the remaining wire; V 余丝实 : The actual volume of the remaining wire; F: The force when the wire pulls the tray to rotate; First, enter the following in the wire and control module: 盘 、m 丝 ,ρ,R 外 , R 内 , h, F; A is calculated using the built-in formula; the specific calculation is as follows: R 外 2 *π*h–R 内 2 *π*h=V 绕 m 丝 / r 丝 =V 丝 Then: A=V 绕 / V 丝 The mechanical sensor can detect the real-time value of the sum of the mass of the material tray and the remaining wire material, and convert it into force N through an electrical signal; N=m*g m=m 盘 +m 余丝 According to the density calculation formula: V 余丝实 =(mm) 盘 ) / p Combining the coefficient A, we get: In 盘余 =A*V 余丝实 but R 余丝 2 *π*h–R 内 2 *π*h=V 盘余 The solution is: The torque balance equation is established based on the method of balancing the roller damping torque by the product of the force and torque of the wire on the roller. The wire moment is: M=F*R 余丝 The moment balance equation is: M d =M The solution is: Set F in the control module. When the remaining wire content changes, the remaining wire mass is converted into the torque R of the wire acting on the roller through the above formula. Establish the required damping torque M of the roller d A linear function of the measured data N of the mechanical sensor is used to achieve real-time adjustment of the roller damping to ensure that the wire will not be over-released during the untangling process; The calculation method of wire excess percentage is as follows: Depend on m=N / g m=m 盘 +m 余丝 have to m 余丝 =N / g-m 盘 but Remaining silk percentage = (m 丝 / m 余丝 )*100% Solved Remaining silk percentage = {m 丝 / (N / gm 盘 )}*100% It can be seen from this that a functional relationship between N and the percentage of remaining wire material is established, and the amount of remaining wire material can be detected by detecting the value of N.

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