WO2025036657A1 - Printing device for a 3d printer - Google Patents

Abstract

A printing device (10) for a 3D printer, comprising a metering device (18) for melting and plasticizing a material (38) to be printed, and a discharging device (14) for printing the material (38) provided via the metering device (18), wherein the metering device (18) and the discharging device (14) are separate from one another and connectable to one another, wherein the discharging device (14) is transportable to the metering device (18) to receive material (38) and, to connect the discharging device (14) to the metering device (18), a coupling point (61) of the discharging device (14) and a coupling point (62) of the metering device (18) come into contact with one another, wherein the metering device (18) has, at a metering delivery opening (50), a coupling element (54) which forms a channel (58), the material (38) dispensed via the metering delivery opening (50) being deliverable to the coupling point (62) of the coupling element (54), and wherein the coupling element (54) has, in the region of the coupling point (62), a closing device (91) for opening and closing the channel (58). The disclosure also relates to a method for operating the printing device (10).

Description

Description

Title:

printing device for a 3D printer

The present invention relates to a printing device for a 3D printer and a method for operating such a printing device.

State of the art

A 3D printer for a material with a variable viscosity receives a solid phase of this material as a starting material, creates a liquid phase from it and applies this liquid phase selectively to the places that belong to the object to be created. Such a 3D printer includes a print head in which the starting material is prepared ready for printing. The material is transported further via channels in the print head.

Furthermore, means are provided for generating a relative movement between the print head and the work surface on which the object is to be created. Either just the print head, just the work surface or both the print head and the work surface can be moved. In order to influence the discharge of the material onto the work surface, an actuator is usually provided in the print head, which applies a force to a dosing zone.

A print head for a 3D printer is known from WO 2018/086792 A1. The print head has a feed through which a raw material to be printed is fed to the print head. This raw material is melted and plasticized in the print head. This melted material is transported within the print head to an outlet opening through which this material is applied to a printing area. DE 10 2019 219 083 A1 discloses a printing device for a 3D printer, comprising a dosing device for melting and plasticizing a material to be printed and a discharge device for printing the material provided via the dosing device, wherein the dosing device and the discharge device are arranged separately from one another and can be connected to one another.

The invention is based on the object of providing a printing device for a 3D printer and a method for operating such a printing device, which enable an optimized printing process, whereby high-quality melt is to be provided in reproducible quality.

disclosure of the invention

Within the scope of the invention, a printing device for a 3D printer was developed. This printing device comprises a dosing device for melting and plasticizing a material to be printed and a discharge device for printing the material provided via the dosing device. The dosing device and the discharge device are arranged separately from one another and can be connected to one another, wherein the discharge device can be transported to the dosing device for receiving material and, in order to connect the discharge device to the dosing device, a coupling point of the discharge device and a coupling point of the dosing device come into contact with one another, wherein the dosing device has a coupling element at a dosing conveyor opening which forms a channel, wherein the material discharged via the dosing conveyor opening can be conveyed to the coupling point of the coupling element.

According to the invention, the coupling element has a closing device in the region of the coupling point for opening and closing the channel.

The dosing device is particularly suitable for supplying raw material, whereby this raw material is melted and plasticized in the dosing device. Furthermore, the melted material can also be provided in doses The discharge device is suitable for dispensing material for producing a 3D body.

The dosing device and the discharge device are thus separated from each other. However, both devices can be connected to each other to receive material. Accordingly, the discharge device has a volume in which a certain amount of the melted material can be received.

It was recognized that this provides advantages over print heads in which the dosing device and the discharge device are provided together in one print head. In particular, by separating the two devices, a smaller weight is moved, which essentially comprises the discharge device with the melted material. Accordingly, the dynamics of such a 3D printer are improved.

By separating the different functions, the corresponding device can be designed more optimally in terms of function. For example, an actuator that exerts a force on the material in the dosing device no longer has any influence on the discharge quantity in the discharge device. This means that the actuators can be designed more cost-effectively and more effectively in terms of the result to be achieved.

Separating the dosing device from the discharge device also has the advantage of improving material utilization. In a print head with a dosing device and discharge device, the introduced material must be used up to prevent the melted material from solidifying later in the discharge device. This means that not all of the material is used, which creates waste. In contrast, only the required amount can be filled into the discharge device from the dosing device. This maximizes material utilization and reduces costs, so that more economical production is possible with this type of printing device. The closing device for opening and closing the channel in the area of the coupling point of the coupling element enables the interface between the channel of the coupling element and the discharge device to be sealed, which advantageously allows a filling process of the dosing device to be optimized. In particular, this filling process, also called refill, can be optimized in terms of time because the material to be melted can be prepared in the dosing device during the printing process of the discharge device. The melting of the material, in particular a material in granulate form, can thus be optimized without causing cycle time losses in the overall system.

This is advantageously achieved by holding the melt in the dosing device or in the coupling element during the printing process of the discharge device. This means that lower temperatures can be achieved in the overall system, since the material does not need to be heated quickly in order to optimize the cycle time of the overall system. The low temperature protects the material, which advantageously leads to improved component quality, in particular improved adhesion between the layers.

Furthermore, energy can be saved, which can advantageously improve the economic efficiency of the overall system and reduce susceptibility to failure.

In a further development, the locking device is arranged on an actuator device for adjusting the locking device. The actuator device controls the locking device.

In a further development, the closing device is designed as a sliding element. The sliding element as a closing device thus advantageously enables the discharge device to be filled without dripping or loss.

In a first embodiment of the invention, the coupling point of the discharge device is arranged on a nozzle of the discharge device. The nozzle is also suitable or intended for discharging the provided material or melt. The nozzle as a coupling point advantageously ensures that the discharge device does not require any further opening for filling.

In a second embodiment of the invention, the coupling point of the discharge device is arranged laterally on the discharge device.

This has the advantage of preventing possible wear on the nozzle during filling.

In a further development, the coupling element has a heating element for tempering the material provided in the channel.

The heating element heats the material provided, or the melt, or maintains a predetermined process temperature before and/or during the feeding of the melt to the discharge device, whereby a homogenized melt can be achieved or maintained in an advantageous manner. The melt temperature can thus be advantageously set in the coupling element. This means that an additional heating zone is available within the overall system.

In a further development, the coupling element has a pressure sensor for measuring the pressure of the material provided in the channel.

In a further development, the discharge device has a discharge piston which is driven by a servo motor so that the material can be discharged for printing.

A servo motor has the advantage of increasing the accuracy and reproducibility of the material discharge from the discharge device. This significantly improves the quality of the workpiece.

In a further development, the dosing device has a dosing piston for discharging the material in the dosing device, whereby, in order to ensure the high forces in the dosing device, the dosing piston for discharging the Material is driven by hydraulics or an electric motor. The dosing piston is also arranged to be movable in the dosing device and exerts a force on the material in the dosing device in order to transport this material from the dosing device into the discharge device. In contrast to the discharge device, which requires a high level of precision, sufficient forces can be provided with the dosing device. By separating the discharge device from the dosing device, each device can be optimized in terms of function.

To increase efficiency, several discharge devices can be provided, which alternately work together with a single dosing device to take in material. This means that only one dosing device is required for several discharge devices. A separate dosing device is therefore not needed for each discharge device. This increases the utilization of the dosing device, so that the efficiency of such a system increases.

The invention additionally provides a method for operating such a printing device.

Short description of the drawing

They show:

Fig. 1 shows an example of a printing device during filling of a discharge device according to the prior art;

Fig. 2 shows an example of a printing device with several discharge devices arranged in different pressure chambers according to the prior art;

Fig. 3 shows a printing device according to the invention of a first embodiment in a first operating state; Fig. 4 shows the printing device according to the invention of the first embodiment in a second operating state and

Fig. 5 shows a printing device according to the invention of a second embodiment in a first operating state.

implementation examples

Fig. 1 shows an example of a printing device 10 for providing a material 38 to be printed from the prior art during filling of a discharge device 14. Fig. 1 is a sectional view of the device 10. In addition to the discharge device 14, the printing device 10 has a metering device 18. The metering device 18 is formed from a base body 22 on which a filling funnel 26 is arranged. A raw material 30, which is in solid form, in particular as granules, can be filled into the filling funnel 26. The filling funnel 26 is directly connected to a metering chamber 34 formed by the base body 22. In this metering chamber 34, the raw material 30 is melted and plasticized to form a printable material 38.

The dosing chamber 34 has a lateral dosing piston opening 42. A dosing piston 46 is arranged in this dosing piston opening 42 and projects into the dosing chamber 34. A dosing piston force FD can be applied to the material 38 in the dosing chamber 34 via the dosing piston 46, so that the material can be pressed in the direction of a dosing feed opening 50 opposite the dosing piston opening 42.

At the metering conveyor opening 50, the metering device 18 has a coupling element 54 which forms a channel 58 so that the material 38 discharged via the metering conveyor opening 50 can be conveyed to a coupling point 62 of the coupling element 54. The discharge device 14 is arranged at the coupling point 62 so that this discharge device 14 can receive the melted material 38 or the melt. The discharge device 14 has a discharge body 66 which forms a discharge chamber 70 in which melted material 38 can be received. A nozzle 74 is formed at an end of the discharge body 66 connected to the coupling point 62, through which the melted material 38 can be received. The material 38 is also applied to a workpiece (not shown) through this nozzle 74.

A discharge piston 78 is arranged within the discharge chamber 70, via which the material 38 can be discharged.

Fig. 2 shows an example of a device 100 according to the prior art with several discharge devices 14, which are arranged in different pressure chambers 102. A different workpiece can be manufactured in each pressure chamber 102. A discharge device 14 is arranged in each pressure chamber 102, each of which is accommodated by a print head body 106. The respective discharge devices 14 can be moved via this.

The device 100 has a transport system 86. Accordingly, several discharge devices 14 can be connected to one another via a single transport system 86. This can improve the utilization of the device 100.

Fig. 3 shows a printing device 10 according to the invention of a first embodiment in a first operating state, this operating state representing a filling process of a discharge device 14 by a dosing device 18. The printing device 10 for a 3D printer comprises the dosing device 18 for melting and plasticizing a material 38 to be printed and the discharge device 14 for printing the material 38 provided via the dosing device 18. The dosing device 18 and the discharge device 14 are arranged separately from one another and can be connected to one another, wherein the discharge device 14 for receiving material 38 can be transported to the dosing device 18 via a transport device 87 and a coupling point 61 of the discharge device 14 and a coupling point 62 of the dosing device 18 come into contact with one another to connect the discharge device 14 to the dosing device 18. The dosing device 18 indicates a dosing conveyor opening 50 has a coupling element 54 which forms a channel 58, wherein the material 38 discharged via the dosing conveyor opening 50 can be conveyed to the coupling point 62 of the coupling element 54. The dosing device 18 has a dosing piston 46 for discharging the material 38 in the dosing device 18, which is driven by a hydraulic system or an electric motor.

The coupling element 54 has a closing device 91 for opening and closing the channel 58 in the area of the coupling point 62. The closing device 91, which is designed as a sliding element, is arranged on an actuator device 90 for adjusting the closing device 91. The sliding element 91 projects from the actuator device 90 through the coupling element 54, projecting into the channel 58.

In the embodiment shown here, the coupling point 62 of the discharge device 14 is arranged on a nozzle 74 of the discharge device 14.

The sliding element 91 has an end 92 which is arranged within the channel 58. The process state shown here shows that the coupling point 62 of the coupling element 54 rests against the coupling point 61 of the discharge device 14 and creates a connection.

The sliding element 91 or the linear slide is opened by means of the actuator device 90 or the actuator at a set time, whereby the previously plasticized material 38 can be pressed into the discharge device 14. This is done by the pressure exerted by the dosing piston 46 of the dosing device 18.

The material 38 located in the channel 58, or the melt, can be pressed through the connection into the discharge device 14. The discharge device 14' shown in dashed lines represents a possible printing position during a printing process.

After filling the discharge device 14 by the dosing device

18, the channel 58 in the area of the coupling point 62 is closed by means of the sliding element 91 closed. Both devices 14, 18 can then carry out a pressure relief. This allows the interfaces 61,

62 drip-free operation after filling must be ensured.

The coupling element 54 has a heating element 98 for controlling the temperature of the material 38 provided in the channel 58. The heating element 98 heats the material 38 in the channel 58 or keeps it at a target temperature required for printing preparation. The coupling element 54 has a pressure sensor 80 for measuring the pressure of the material 38 provided in the channel 58. The pressure sensor 80 determines the melt pressure within the channel 58, whereby the evaluation of the pressure can be used for process optimization.

Fig. 4 shows the printing device 10 according to the invention of the first embodiment in a second operating state, wherein this operating state represents a printing process of the discharge device 14.

The structure is analogous to the structure shown in Fig. 3, whereby here the dosing unit 14, transported by the transport device 87, is in a pressure position. The discharge device 14' shown in dashed lines represents a possible filling position, as described in Fig. 3.

The sliding element 91 rests with its end 92 in the area of the coupling point 62 of the coupling element 54 and closes it. As a result, no material 38 or melt can escape from the channel 58 of the coupling element 54. The channel 58 is thus closed.

The discharge device 14 has a discharge piston 78, which can be driven by a servo motor and thus the material 38 can be discharged for printing.

While the printing is being carried out by the discharge device 14, the dosing device 18 can prepare the channel 58 of the coupling element 54 with new material 38 or with new melt. Fig. 5 shows a printing device 10 according to the invention of a second embodiment in an operating state, this operating state representing a printing process of the discharge device 14. The structure and the mode of operation are essentially analogous to the first embodiment of the invention. The difference is that the coupling point 61, 61' of the discharge device 14 is arranged laterally on the discharge device 14.

Here too, the dosing device 18 and the discharge device 14 are arranged separately from one another and can be connected to one another, wherein the discharge device 14 can be transported to the dosing device 18 via the transport device 87 in order to receive material 38, and the coupling point 61 of the discharge device 14 and the coupling point 62 of the dosing device 18 can come into contact with one another in order to connect the discharge device 14 to the dosing device 18. In this embodiment, the coupling point 62 of the dosing device 54 is arranged in the pressure direction of the dosing piston 46. The dosing device 18 has the coupling element 54 on the dosing conveying opening 50, which forms the channel 58, wherein the material 38 discharged via the dosing conveying opening 50 can be conveyed to the coupling point 62 of the coupling element 54. The dosing device 18 has the dosing piston 46 for discharging the material 38 in the dosing device 18, which is driven by a hydraulic system or an electric motor.

The coupling element 54 has the closing device 91 for opening and closing the channel 58 in the area of the coupling point 62. The closing device 91, which is designed as a sliding element, is arranged on the actuator device 90 for adjusting the closing device 91. The sliding element 91 projects from the actuator device 90 through the coupling element 54, projecting into the channel 58.

The coupling element 54 has a heating element 98 for controlling the temperature of the material 38 provided in the channel 58. The heating element 98 heats the material 38 in the channel 58 or keeps it at a target temperature required for printing preparation. The coupling element 54 has the pressure sensor 98 for measuring the pressure of the material 38 provided in the channel 58. The pressure sensor 98 determines the melt pressure within the channel 58, whereby the evaluation of the pressure can be used for process optimization.

The discharge device 14' shown in dashed lines with its laterally arranged coupling point 61' represents a possible filling position.

The sliding element 91 rests with its end 92 in the area of the coupling point 62 of the coupling element 54 and closes it. As a result, no material 38 or melt can escape from the channel 58 of the coupling element 54. The channel 58 is thus closed.

The discharge device 14 has a discharge piston 78, which can be driven by a servo motor and thus the material 38 can be discharged for printing. The laterally arranged coupling point 61 of the discharge unit 14 is closed after filling and is only opened again for filling after it has been placed on the coupling point 62 of the coupling element 54.

Fig. 3 to Fig. 5 show the printing device 10 and also describe a method for operating the printing device 10, wherein the discharge device 14 has used up the entire material 38 or the volume of the melt during printing. The discharge device 14 must then be refilled, for which purpose the discharge device 14 is coupled to the dosing device 18 with the coupling element 54. The already preheated material 38 or granulate is then plasticized in one batch and filled into the discharge device 14 via the channel 58 of the coupling element 54. The printing device 10 according to the invention is able to prepare and plasticize the granulate simultaneously during printing. If the coupling points 61, 62 or the interface are coupled, the closing device 91 or the linear slide opens the channel 58 to the discharge device 14 and the melt 38 can flow into it.

If the discharge device 14 is filled, the channel 58 can be closed by the closing device 91 or the linear slide. The coupling points 61, 62 or the interface can thus be uncoupled. During execution of the method, the pressure sensor 80 can be used to set the ideal melt pressure within the channel 58 or to prepare the melt 38.

The printing device 10 is arranged modularly within a possible 3D printing system. For filling or refilling, the printing process is briefly interrupted and the discharge device 14 is fed to the dosing device 18.

Thanks to the integrated heater 98 within the coupling element 54, the interruption caused by the filling process can be kept very short. The extended closure function provided by the closing device 91 enables the melt 38 to be held within the coupling element 54 and the dosing device 18, whereby the melt 38 is already fully plasticized and homogenized when the discharge device 14 is coupled. Likewise, the closing device 91 or the linear slide and its closure function enable drip-free and loss-free filling.

Furthermore, after filling and closing the channel 58, a target pressure of the melt 38 within the discharge device 14 can be set by moving the discharge piston 78.

Claims

claims 1 . Printing device (10) for a 3D printer, comprising a dosing device (18) for melting and plasticizing a material (38) to be printed and a discharge device (14) for printing the material (38) provided via the dosing device (18), wherein the dosing device (18) and the discharge device (14) are arranged separately from one another and can be connected to one another, wherein the discharge device (14) can be transported to the dosing device (18) for receiving material (38), and in order to connect the discharge device (14) to the dosing device (18), a coupling point (61) of the discharge device (14) and a coupling point (62) of the dosing device (18) come into contact with one another, wherein the dosing device (18) has a coupling element (54) at a dosing conveyor opening (50) which forms a channel (58), wherein the Material (38) discharged from the metering conveyor opening (50) can be conveyed to the coupling point (62) of the coupling element (54), characterized in that the coupling element (54) has a closing device (91) for opening and closing the channel (58) in the region of the coupling point (62). 2. Printing device (10) according to claim 1, characterized in that the closing device (91) is arranged on an actuator device (90) for adjusting the closing device (91). 3. Printing device (10) according to one of the preceding claims, characterized in that the closing device (91) is designed as a sliding element. 4. Printing device (10) according to one of the preceding claims, characterized in that the coupling point (62) of the discharge device (14) is arranged on a nozzle (74) of the discharge device (14). 5. Printing device (10) according to one of claims 1 to 3, characterized in that the coupling point (62) of the discharge device (14) is arranged laterally on the discharge device (14). 6. Printing device (10) according to one of the preceding claims, characterized in that the coupling element (54) has a heating element (98) for tempering the material (38) provided in the channel (58). 7. Printing device (10) according to one of the preceding claims, characterized in that the coupling element (54) has a pressure sensor (98) for measuring the pressure of the material (38) provided in the channel (58). 8. Printing device (10) according to one of the preceding claims, characterized in that the discharge device (14) has a discharge piston (78) which is driven by a servo motor, so that the material (38) can be discharged for printing. 9. Printing device (10) according to one of the preceding claims, characterized in that the dosing device (18) has a dosing piston (46) for discharging the material (38) in the dosing device (18), which is driven by a hydraulic system or an electric motor. 10. Method for operating a printing device (10) according to one of the preceding claims.