Pulse type powder quantitative supply device and method thereof

Abstract

The present invention provides a pulse-type powder quantitative supply device and method thereof, the device includes a rigid cavity, an opening and closing unit, a pulse control unit and a discharging unit, a powder spreading platform located at the bottom of the rigid cavity and a powder storage container arranged above the powder spreading platform and fixed to the top of the rigid cavity for storing material powder, the powder storage container has a powder storage cavity, the opening and closing unit is arranged inside the powder storage container and below the powder storage cavity, the discharging unit is located between the powder storage cavity and the opening and closing unit, the discharging unit has a discharge port, and the discharge port is connected to the powder storage cavity, the pulse control unit is connected to the opening and closing unit and can control the opening and closing unit to be alternately in an open state or a closed state, when the opening and closing unit is in the open state, the material powder can fall onto the powder spreading platform through the discharge port to form a target powder spreading surface, and when the opening and closing unit is in the closed state, the material powder is blocked above the opening and closing unit. The device has the characteristics of fast powder discharge speed and controllable powder supply.

Description

Technical Field

[0001] The present invention relates to the field of 3D printing, and in particular to a pulsed powder quantitative supply device and method thereof. Background Art

[0002] As the performance of 3D printing equipment continues to improve, different types of 3D printing processes and equipment are becoming increasingly sophisticated, enabling the use of a growing number of materials with varying textures and physical forms, providing more diverse options for the advancement and development of various industries. Different printing processes are determined by the type and form of the materials used. From a material form perspective, these include solid filaments (hot melt extrusion, or FDM), solid powders (hot melt bonding, or SLS, melt fusion, or SLM, and direct metal deposition, or DMD), and liquid materials (stereolithography, or SLA). For solid powder materials, the use of laser galvanometer two-dimensional scanning or inkjet printing technology in the processing method can achieve capabilities similar to planar two-dimensional processing, with extremely high printing efficiency. The adaptability of the forming principle of powder materials is also relatively broad, such as hot melt bonding (SLS), hot melt bonding (SLM), and chemical reaction bonding (inkjet sand mold printing). Therefore, the powder material 3D printing process also has a relatively wide range of applications, and is increasingly used in personal consumption, design prototype verification, industrial mass production and other fields. Among them, hot melt bonding (SLM) process equipment has high precision and structural performance of its formed parts, and is also widely used in aerospace, medical and other fields.

[0003] On the other hand, in additive manufacturing equipment using powder materials, existing solutions for powder material delivery, such as quantitative supply and uniform powder distribution within powder bed equipment, have limited further performance improvements. Powder bed equipment such as SLS and SLM utilizes two feed methods: top-down and bottom-down. The top-down method is widely used in SLS and SLM equipment due to its compact structure and ability to achieve continuous external powder supply. The top-down method must fulfill two primary functions: quantitative powder supply and matching the powder distribution on one side of the powder bed with the required powder distribution. These two functions ensure sufficient powder is supplied to lay a layer without excessive excess powder waste. The existing method for quantitative powder supply is to use a servo motor to drive the powder supply gear to rotate and use the gear groove to achieve quantitative powder supply. This method has a complex gear installation structure, a low powder output speed, and is prone to powder jamming and leakage. At the same time, the powder amount distribution after powder supply and the matching of the powder bed shape are not matched. As the printing format continues to increase, if there is no effective corresponding solution, the powder cannot be fully utilized, reducing the powder utilization efficiency.

[0004] Currently, there is a lack of a pulsed powder quantitative supply method for hot-melt bonding (SLS) and melt-molding (SLM) equipment that has a fast powder output speed, good adaptability to the powder supply width, and controllable powder supply distribution. Summary of the Invention

[0005] In view of this, it is necessary to provide a pulsed powder quantitative supply device and method thereof to address the above problems, which has the characteristics of fast powder output speed, controllable powder supply amount and powder supply distribution.

[0006] The present invention provides a pulse-type powder quantitative supply device, comprising a rigid cavity, a powder spreading platform located at the bottom of the rigid cavity, and a powder storage container arranged above the powder spreading platform and fixed to the top of the rigid cavity for storing material powder. The pulse-type powder quantitative supply device also includes an opening and closing unit, a pulse control unit, and a discharging unit. The powder storage container has a powder storage cavity, the opening and closing unit is arranged inside the powder storage container and below the powder storage cavity, the discharging unit is located between the powder storage cavity and the opening and closing unit, and the discharging unit has a discharge port, which is connected to the powder storage cavity. The pulse control unit is connected to the opening and closing unit and can control the opening and closing unit to be alternately in an open state or a closed state; when the opening and closing unit is in the open state, the material powder can fall onto the powder spreading platform through the discharge port to form a target powder spreading surface, and when the opening and closing unit is in the closed state, the material powder is blocked above the opening and closing unit.

[0007] With this arrangement, the pulse control unit sends pulse control signals to control the alternating opening and closing of the opening and closing unit. This allows the material powder to be spread onto the powder spreading platform under the action of gravity whenever the unit is in the open state. Whenever the unit is in the closed state, the powder spreading process is stopped, allowing the material powder at the discharge port of the discharge unit to reach a uniform state, ready for powder spreading the next time the opening and closing unit is in the open state. The pulse control unit can control the duration of a single pulse and, combined with the size of the discharge port, can achieve quantitative control of the powder supply and achieve a high powder discharge speed.

[0008] In one embodiment of the present invention, the opening and closing unit includes an air cavity shell arranged on the inner wall of the powder storage container. When the opening and closing unit is in a closed state, the closed part of the air cavity shell is in surface contact; when the opening and closing unit is in an open state, the air cavity shell forms an opening, wherein the size of the opening is larger than the size of the discharge port.

[0009] With such a configuration, when the opening and closing unit is in the open state, the air cavity shell will not affect the powder spreading process of the material powder. In addition, the air cavity shell can be in a closed state when inflated. When in the closed state, the surface contact closing method better prevents the material powder from falling onto the powder spreading platform and better realizes the quantitative supply of material powder under a single pulse.

[0010] In one embodiment of the present invention, the pulse control unit includes a controller, an air compressor, a positive and negative pressure converter and a three-way electrically controlled air valve, the three-way electrically controlled air valve is respectively connected to the air compressor, the positive and negative pressure converter and the air cavity shell, the positive and negative pressure converter is connected to the air cavity shell, and the controller is electrically connected to the three-way electrically controlled air valve.

[0011] With this arrangement, the air cavity shell formed by the opposite opening and closing units can be inflated or evacuated to realize the control of the opening and closing state of the opening and closing units. In addition, the controller can control and set the pulse time, and can further adjust the precise control of the quantity during a single pulse.

[0012] In one embodiment of the present invention, the pulse-type powder quantitative supply device also includes a valve unit arranged at the bottom of the powder storage container, the valve unit includes a baffle hinged at one end to the side wall of the powder storage container, an elastic element with two ends respectively arranged on the baffle and the inner wall of the powder storage container, and a drive cylinder with two ends respectively arranged on the baffle and the inner wall of the powder storage container, and the drive cylinder is connected to the air compressor.

[0013] With this arrangement, when the device provided by the present invention is activated, the valve unit can inflate the drive cylinder with gas, thereby opening the valve unit's baffle relative to the powder storage container, allowing powder to be supplied to the powder spreading platform when the opening and closing unit is in the open state. When the device provided by the present invention is deactivated, the gas in the drive cylinder is withdrawn, and the elastic element seals the bottom opening of the powder storage container through the baffle, thereby sealing the powder storage container and preventing material powder from falling onto the powder spreading platform.

[0014] In one embodiment of the present invention, the pulse control unit further includes an electromagnetic valve, which is disposed between the driving cylinder and the air compressor, and is electrically connected to the controller.

[0015] With such an arrangement, the valve unit can be better controlled through the arrangement of the electromagnetic valve.

[0016] In one embodiment of the present invention, the discharging unit includes a supporting protrusion arranged inside the powder storage container, and a discharging support plate arranged on the supporting protrusion, and the discharging port is arranged on the discharging support plate.

[0017] This arrangement solves the problem of replacing the discharge support plate. By replacing different discharge support plates, different discharge openings can be created, allowing for adjustment of the powder discharge amount per pulse. The discharge support plate can be fixed to the support protrusion under the gravity pressure of the powder. When a different-sized discharge support plate is needed, it can be easily removed from above the support protrusion.

[0018] In one embodiment of the present invention, the discharging unit further includes a position-limiting seal, and the discharging support plate is disposed between the supporting protrusion and the position-limiting seal.

[0019] In this way, in order to prevent the discharging support plate from being subjected to the upward force of the opening and closing unit during the process of the opening and closing unit changing its state (including from the open state to the closed state, or from the closed state to the open state), causing the discharging support plate to vibrate or move, a limiting seal is provided above the discharging support plate.

[0020] In one embodiment of the present invention, the limiting seal comprises a limiting hole formed on the side wall of the powder storage container and a sealing member detachably and sealingly connected to the limiting hole and partially protruding from the inner wall of the powder storage container.

[0021] With such arrangement, the arrangement of the limiting holes and the sealing member enables more convenient disassembly to achieve replacement of the discharge support plate.

[0022] In one embodiment of the present invention, the discharge port is a rectangular hole.

[0023] In this way, the discharge port is set as a rectangular hole. Since the length of the rectangular hole is not less than the length of the powder spreading platform, the width of different rectangular holes will affect the powder discharge per unit time. The wider the width, the more powder discharge. Setting the discharge port as a regular rectangle can ensure that the single powder discharge is uniform in the length direction. After multiple pulse powder discharges, the distribution of the total material powder is also uniform.

[0024] The present invention also provides a pulse powder quantitative supply method, which uses the pulse powder quantitative supply device described above, and the method includes:

[0025] The pulse control unit sends a pulse control signal to control the opening and closing unit;

[0026] In response to the pulse control signal emitted by the pulse control unit, the opening and closing unit is alternately in an open state or a closed state; whenever the opening and closing unit is in the open state, the material powder can fall onto the powder spreading platform through the discharge port to form a target powder spreading surface, and whenever the opening and closing unit is in the closed state, the material powder is blocked above the opening and closing unit.

[0027] In one embodiment of the present invention, the step of sending a pulse control signal by the pulse control unit to control the opening and closing unit further includes the following steps:

[0028] The controller sends a pulse control signal to control the three-way electric-controlled gas valve to alternately connect and close;

[0029] The three-way electrically controlled air valve responds to the pulse control signal to control the positive and negative pressure converters to be alternately in the inflation state or the exhaust state. When the positive and negative pressure converters are in the inflation state, the opening and closing unit can be controlled to be in the closed state; when the positive and negative pressure converters are in the exhaust state, the opening and closing unit can be controlled to be in the open state.

[0030] In one embodiment of the present invention, before the step of sending a pulse control signal through the controller to control the three-way electrically controlled gas valve to alternately connect and close, the step further includes:

[0031] A control signal is sent to the electromagnetic valve through the controller, and the electromagnetic valve controls the valve unit to be in a working state. When the valve unit is in a working state, the baffle of the valve unit is opened under the action of the driving cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of a pulse type powder quantitative supply device of the present invention.

[0033] Figure 2 This is a structural schematic diagram of a pulse-type powder quantitative feeding device according to the above embodiment of the present invention when not in operation.

[0034] Figure 3 This is a structural schematic diagram of an opening and closing unit of a pulse-type powder quantitative feeding device according to the above embodiment of the present invention when it is in an open state.

[0035] Figure 4 This is a structural schematic diagram of a pulse-type powder quantitative feeding device according to the above embodiment of the present invention when the opening and closing unit is in a closed state and the valve unit is in an open state.

[0036] Figure 5 This is a block diagram showing the connection between a controller and other devices of a pulsed powder quantitative supply device according to the above embodiment of the present invention.

[0037] 10. Rigid cavity; 20. Powder storage container; 21. Powder storage cavity; 30. Opening and closing unit; 31. Air cavity shell; 32. Opening port; 40. Discharging unit; 41. Discharging port; 42. Support protrusion; 43. Discharging support plate; 44. Positioning seal; 50. Pulse control unit; 51. Controller; 52. Air compressor; 53. Positive and negative pressure converter; 54. Three-way electrically controlled air valve; 60. Valve unit; 61. Baffle; 62. Elastic element; 63. Drive cylinder; 64. Solenoid air valve; 65. Sealing gasket; 70. Powder spreading platform; 80. Material powder. DETAILED DESCRIPTION

[0038] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] It should be noted that when a component is referred to as being "mounted on" another component, it may be mounted directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component. When a component is considered to be "fixed to" another component, it may be directly fixed to the other component or there may be a central component.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] See also Figure 1 , is a schematic diagram of the structure of a pulsed powder quantitative supply device in one embodiment of the present invention. The present invention provides a pulsed powder quantitative supply device for quantitatively supplying powder to a printing device. The present invention provides a pulsed powder quantitative supply device for supplying material powder to a thermally melt bonded (SLS) or thermally melt bonded (SLM) device. The device features a fast powder output speed, good adaptability to the powder supply width, and controllable powder supply distribution. In the present invention, the material powder refers to toner powder.

[0042] like Figure 1 Hezhi Figure 3As shown, the present invention provides a pulse-type powder quantitative supply device, including a rigid cavity 10, a powder storage container 20, an opening and closing unit 30, a discharging unit 40, a valve unit 60 and a powder spreading platform 70, wherein the powder spreading platform 70 is located at the bottom of the rigid cavity 10, the powder storage container 20 is arranged above the powder spreading platform 70 and fixed to the top of the rigid cavity 10 for storing material powder 80, the powder storage container 20 has a powder storage cavity 21 located at the upper part of the powder storage container 20, and the powder storage cavity 21 is used to store material powder 80. The opening and closing unit 30 is arranged inside the powder storage container 20 and is located below the powder storage chamber 21. The discharging unit 40 is located between the powder storage chamber 21 and the opening and closing unit 30. The discharging unit 40 has a discharging port 41, which is connected to the powder storage chamber 21 so that the material powder 80 in the powder storage chamber 21 can fall onto the powder spreading platform 70 through the discharging port 41. The pulse control unit 50 is connected to the opening and closing unit 30 and can control the opening and closing unit 30 to be alternately in an open state or a closed state; when the opening and closing unit 30 is in the open state, the material powder 80 can fall onto the powder spreading platform 70 through the discharging port 41. 0 has formed a target powder spreading surface. When the opening and closing unit 30 is in the closed state, the material powder 80 is blocked above the opening and closing unit 30. The pulse control unit 50 sends a pulse control signal to control the alternating opening and closing of the opening and closing unit 30, so that whenever it is in the open state, the material powder 80 can be spread on the powder spreading platform 70 under the action of gravity. Whenever it is in the closed state, the powder spreading process of the material powder 80 is stopped, so that the material powder 80 at the discharge port 41 of the discharge unit 40 tends to a consistent state, so as to prepare for powder spreading the next time the opening and closing unit 30 is in the open state. The pulse control unit 50 can control the time of a single pulse and, in combination with the size of the discharge port 41, can achieve quantitative control of the powder supply and have the characteristics of fast powder discharge speed. It is worth mentioning that the so-called "pulse type" here means that the opening and closing unit 30 is alternately in the open and closed states. One open state plus one closed state is a single pulse. The time of the single pulse can be set by the pulse control unit 50. The time of the single pulse is equal to the time of maintaining the open state plus the time of maintaining the closed state.

[0043] like Figure 2As shown, the opening and closing unit 30 may include an air cavity housing 31 disposed on the inner wall of the powder storage container 20. When the opening and closing unit 30 is closed, the closed portion of the air cavity housing 31 forms a surface contact. When the opening and closing unit 30 is open, the air cavity housing 31 forms an opening 32. The opening is larger than the size of the discharge port 41, so that the material powder 80 does not contact the air cavity housing during the powder spreading process. The air cavity housing 31 can be closed when inflated. In this closed state, the surface contact closure effectively prevents the material powder 80 from falling onto the powder spreading platform 70, thereby better achieving quantitative supply of the material powder 80 in a single pulse. Preferably, the air cavity housing 31 can control its volume expansion and contraction through positive or negative pressure, thereby controlling the flow of the material powder 80 from the powder storage container 20. The surface material of the air cavity housing 31 can have a certain degree of toughness and softness to effectively block the flow of the material powder 80. Specifically, when the air cavities at both ends of the air cavity housing 31 are inflated, they contact and close beneath the discharge unit 40. The two contact surfaces at the closed position have a certain thickness and toughness. Even if powdered material 80 is present between the two closed surfaces after closure, the surface material will passively deform according to the shape of the powder, securing the powdered material 80 between the contact surfaces without affecting the overall closure of the two closed surfaces.

[0044] Of course, those skilled in the art should understand that in other embodiments of the present invention, the air cavity shells 31 may also be provided as at least two, with at least two air cavity shells 31 being provided opposite to each other on the inner wall of the powder storage container 20 .

[0045] Furthermore, regarding the issue of consistency throughout the opening and closing process of the opening and closing unit 30, in addition to the fact that the positive and negative pressure converters 53 can expand or contract the entire air cavity within the air cavity housing 31 during inflation or degassing, the contact surface material of the air cavity housing 31 has a certain degree of toughness, so the position that expands or contracts first will also drive the movement of the adjacent positions, thereby improving the consistency of the opening and closing unit 30 during opening and closing. Furthermore, as can be seen from the structure of the opening and closing unit 30 provided by the present invention, the opening and closing unit 30 provided by the present invention has a simple structure, and the air cavity housing 31 has a flexible structure, which has good adaptability to powders 80 of different materials.

[0046] like Figure 1 and Figure 2As shown, in order to better control the air cavity housing 31 of the opening and closing unit 30 so that it can be pulsed between the open and closed states, in one embodiment of the present invention, the pulse control unit 50 may include a controller 51, an air compressor 52, a positive and negative pressure converter 53, and a three-way electrically controlled air valve 54. The three-way electrically controlled air valve 54 is respectively connected to the air compressor 52, the positive and negative pressure converter 53, and the air cavity housing 31. The positive and negative pressure converter 53 is connected to the air cavity housing 31. The controller 51 is electrically connected to the three-way electrically controlled air valve 54. The controller 51 sends a pulse control signal to control the three-way electrically controlled air valve 54, thereby controlling the positive and negative pressure converter 53 to alternately inflate or deflat the air cavity housing 31 formed opposite to the opening and closing unit 30, thereby achieving pulsed control of the opening and closing states of the opening and closing unit 30. The controller 51 can control and set the time of a single pulse, and can further adjust the precise control of the quantity during a single pulse. The pulse control signal sent by the controller 51 here can be understood as the controller 51 sending an instruction to control the alternating opening and closing of each channel of the three-way electrically controlled air valve 54 to realize pulsed inflation or exhaust of the positive and negative pressure exchanger 53, thereby realizing pulsed control of the opening and closing state of the opening and closing unit 30.

[0047] like Figure 2 As shown, the discharge unit 40 includes a support protrusion 42 disposed within the powder storage container 20, and a discharge support plate 43 disposed on the support protrusion 42. A discharge port 41 is disposed on the discharge support plate 43. Preferably, the discharge port 41 is configured as a rectangular hole. Preferably, the discharge port 41 is an elongated rectangular hole. Because the support protrusion 42 supports the discharge support plate 43, the length and width of the discharge support plate 43 can be adapted to the dimensions of the powder storage container 20, so that the discharge support plate 43 can be precisely placed within the powder storage container 20 and supported by the support protrusion 42.

[0048] Further, if Figure 2As shown, to prevent the discharge support plate 43 from being squeezed by the opening and closing unit 30 during state changes (including from an open state to a closed state, or vice versa), which could cause the discharge support plate 43 to move upward, a position-limiting seal 44 is provided above the discharge support plate 43. The discharge support plate 43 is positioned between the support protrusion 42 and the position-limiting seal 44. Preferably, the position-limiting seal 44 comprises a position-limiting hole formed in the sidewall of the powder storage container 20 and a seal 65 that is removably and sealingly connected to the position-limiting hole and partially protrudes from the inner wall of the powder storage container 20. Here, the position-limiting hole can be implemented as a threaded hole, and the seal 65 can be implemented as a screw adapted to fit within the threaded hole. Thus, the discharge support plate 43 of the discharge unit 40 provided by the present invention is replaceable. Furthermore, by adjusting the size of the discharge opening 41 of the discharge support plate 43, the distribution requirements of different powder materials 80 can be achieved, thereby enhancing the versatility and applicability of the device.

[0049] like Figure 3 and Figure 4 The figures show the opening and closing unit 30 of the pulsed powder quantitative feeding device provided by the present invention in both the open and closed states. When the opening and closing unit 30 is in the open state, at least two opposed air cavity shells 31 form an opening 32. This opening 32 corresponds to the discharge port 41, allowing the powdered material 80 within the powder storage chamber 21 to fall through the discharge port 41. When the opening and closing unit 30 is in the closed state, the powdered material 80 is blocked above the opening and closing unit 30.

[0050] Specifically, the pulsed quantitative powder supply mechanism provided by the present invention is implemented as follows: the pressure exerted on the discharge support plate 43 mounted within the powder storage container 20 is only affected by the installation angle and powder storage capacity of the powder storage container 20. External powder supply and storage circuits are designed to prevent any impact on the pressure of the discharge unit 40, such as by using a transverse pipeline to supply powder to the powder storage container 20. Therefore, at the moment the opening and closing unit 30 below the discharge support plate 43 opens, the pressure and gravity exerted on the same type of powder 80 at the discharge port 41 are stable and unaffected by external powder circuit conditions. When the opening and closing unit 30 opens, the powder 80 located in or above the discharge port 41 on the discharge support plate 43 will initially free fall downward. As the powder 80 below gradually flows out, the powder 80 above will begin to flow downward. The farther the powder 80 is from the discharge port 41, the less likely its direction and speed are to approach free fall, and thus, the more likely it will be disturbed by the flow of powder 80 in all directions. Therefore, since the size of the discharge port 41 is fixed, the amount and distance that the material powder 80 falls within a certain period of time are stable. The time of a single pulse is set by the controller 51. More specifically, the time during which the opening and closing unit 30 maintains the open and closed states is set within the single pulse time to ensure that the material powder 80 that falls in a form close to free fall is allowed to flow out, so that the material powder 80 in free fall can be stably separated.

[0051] Ensure that the opening and closing unit 30 is in an open or closed state in a pulse manner with a certain frequency, so that the time point when the material powder 80 flows out is always when the material powder 80 in the powder storage chamber 21 is stationary, and then the state of the material powder 80 inside the powder storage chamber 21 is the same each time the air cavity shell 31 of the opening and closing unit 30 is opened. This is because the opening and closing unit 30 maintains the open state for the same time each time, and it can be determined that the powder output in each open state is unchanged. In this way, a continuous pulse material powder 80 with the same powder output each time is obtained. Before the material powder 80 of a certain material, the pulse control unit 50 controls the opening and closing unit 30 to continuously pulse out powder m times, and then weighs the total weight k of the material powder 80, and the weight of the powder output in a single pulse can be obtained as k / m. During the use of the device, the total powder output is controlled according to the powder output of a single pulse and the number of pulse powder outputs. It can be seen from this that the pulse-type powder quantitative supply device provided by the present invention has controllable powder output consistency and a stable powder output state. In this state, powder is output with the same amount of powder output each time. After calibrating the total amount of powder output and the number of pulses of the newly used material powder 80, the powder output can be accurately controlled.

[0052] In addition, to better control the powder supply speed and the uniform distribution of the material powder 80, the powder supply speed can be controlled by changing the width of the discharge port 41. For example, the discharge port 41 on the discharge support plate 43 is implemented as a rectangular hole, and the length of this rectangular hole should be ensured to be not less than the length of the target powder spreading surface. Different widths correspond to different amounts of the material powder 80 falling in a near-free-fall motion. Since the falling distance is the same, the time interval between each opening state and closing state of the opening and closing unit 30 is the same. As a result, the wider the width of the discharge port 41, the faster the powder output speed. The discharge port 41 is a regular rectangle, so the powder output in the length direction is uniform each time. After multiple pulsed powder outputs, the distribution of the material powder 80 is also uniform. When the powder spreading surface is relatively wide, the width of the opening 32 of the corresponding opening and closing unit 30 should be ensured to be not less than the width of the powder spreading surface. When gas is filled into the gas chamber housing 31 of the opening and closing unit 30 to make it in the closed state or gas is extracted to make it in the opening state, according to the relationship between the falling distance and time of a freely falling object s = 0.5×at², where a is the acceleration with a value of 9.8 m / s² and s is the distance from the discharge support plate 43 to the lower surface of the gas chamber housing 31, it is obtained that the time for the opening and closing unit 30 to be in the opening state and maintained is about t at seconds. During this time, the material powder 80 with the same state will fall onto the powder spreading platform 70. When the opening and closing unit 30 is in the closed state, the other falling material powder 80 will be blocked above the opening and closing unit 30 or fixed between the contact surfaces of the opposing gas chamber housings 31. The time for the opening and closing unit 30 to maintain the closed state is determined according to the static time required for the material powder 80 in the powder storage chamber 21. Especially in the powder spreading application with a large area, the device provided by the present invention can be well extended and adapted, with higher stability and lower complexity compared to the traditional method.

[0053] In addition, in order to improve the control of the powder supply speed and accuracy, the pulsed powder quantitative supply device provided by the present invention can improve the accuracy of single - time powder supply by adjusting the time of a single pulse. For example, since the amount of powder in a near - free - fall is fixed, the time for these powders to fall is fixed. At this time, assume that in a single pulse, the time for the opening and closing unit 30 to maintain the open state is t1, and the fixed powder output amount is w1. Adjust the time t1 to t2 (where t2 < t1). Therefore, the powder output amount per pulse can be adjusted to w2 (at this time w2 < w1), so as to achieve a smaller powder output amount per single pulse and improve the accuracy of powder output amount control.

[0054] Such as Figures 1 to 4As shown, to ensure that the material powder 80 does not flow downward after the device provided by the present invention is powered off and in standby mode, the pulse-type powder quantitative supply device also includes a valve unit 60 disposed at the bottom of the powder storage container 20. The valve unit 60 includes a baffle 61 hinged at one end to the side wall of the powder storage container 20, an elastic element 62 with two ends respectively disposed on the baffle 61 and the inner wall of the powder storage container 20, and a drive cylinder 63 with two ends respectively disposed on the baffle 61 and the inner wall of the powder storage container 20. The drive cylinder 63 is connected to the air compressor 52. When the device provided by the present invention is activated, the valve unit 60 can fill the drive cylinder 63 with gas to rotate the baffle 61 of the valve unit 60 along the hinged position, thereby opening the bottom opening of the powder storage container 20, so that powder can be supplied to the powder spreading platform 70 when the opening and closing unit 30 is in the open state. When the pulsed powder quantitative feeding device stops operating, the gas in the driving cylinder 63 is extracted, and under the action of the elastic element 62, the bottom opening of the powder storage container 20 is sealed through the baffle 61, thereby sealing the powder storage container 20 and preventing the material powder 80 from falling onto the powder spreading platform 70. Preferably, the elastic element 62 can be implemented as a spring.

[0055] In other embodiments of the present invention, a sealing gasket 65 is provided at one end of the baffle 61 to better seal the bottom opening of the powder storage container 20. Alternatively, a sealing gasket (not shown) may be provided on the side wall of the powder storage container 20 near the bottom opening to better seal the bottom opening. Of course, those skilled in the art will understand that when the sealing gasket 65 is provided at one end of the baffle 61, it is provided at the end away from the hinged connection between the baffle 61 and the powder storage container 20, so that the sealing gasket 65 can seal the bottom opening of the powder storage container 20. Therefore, when the device provided by the present invention is powered off and shut down, the spring pulls the baffle 61 to keep it in a closed state, and there is a sealing gasket 65 at the closed position of the baffle 61 and the side wall of the powder storage container 20. The amount of material powder 80 stored between the discharge support part and the air-controlled valve unit 60 is small, and most of the pressure of the material powder 80 in the entire powder box is borne by the discharge support plate 43. The baffle 61 of the air-controlled valve unit 60 is mostly naturally accumulated with material powder 80, so it can meet the sealing requirements of the material powder 80 in standby mode.

[0056] In order to better automatically control the valve unit 60, as Figure 2 and Figure 5 As shown, the pulse control unit 50 further includes an electromagnetic valve 64 . The electromagnetic valve 64 is disposed between the driving cylinder 63 and the air compressor 52 . The electromagnetic valve 64 is electrically connected to the controller 51 .

[0057] With respect to the above-mentioned pulsed powder quantitative working device, the present invention further provides a pulsed powder quantitative supply method, which may include:

[0058] The pulse control unit 50 sends a pulse control signal to control the opening and closing unit 30;

[0059] In response to the pulse control signal sent by the pulse control unit 50, the opening and closing unit 30 is alternately in an open state or a closed state.

[0060] In one embodiment of the present invention, the step of sending a pulse control signal by the pulse control unit 50 to control the opening and closing unit 30 may further include the following steps:

[0061] The controller 51 sends a pulse control signal to control the three-way electric-controlled air valve 54 to alternately connect and close;

[0062] The three-way electrically controlled air valve 54 responds to the pulse control signal to control the positive and negative pressure converter 53 to be alternately in the inflation state or the exhaust state. When the positive and negative pressure converter 53 is in the inflation state, it can control the opening and closing unit 30 to be in the closed state; when the positive and negative pressure converter 53 is in the exhaust state, it can control the opening and closing unit 30 to be in the open state.

[0063] In one embodiment of the present invention, before the step of sending a pulse control signal through the controller 51 to control the three-way electric-controlled gas valve 54 to alternately connect and close, the following steps may be further included:

[0064] The controller 51 sends a control signal to the electromagnetic valve 64 , and the electromagnetic valve 64 controls the valve unit 60 to be in a working state. When the valve unit 60 is in a working state, the baffle 61 of the valve unit 60 is opened under the action of the driving cylinder 63 .

[0065] The specific implementation of the pulse-type powder quantitative supply method provided by the present invention has been introduced in detail when introducing the pulse-type powder quantitative supply, and will not be repeated here.

[0066] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present invention and are not intended to limit the present invention. Any appropriate changes and modifications to the above embodiments fall within the scope of the present invention as long as they are within the spirit of the present invention.

Claims

1. A pulsed powder quantitative supply device, comprising a rigid cavity (10), a powder spreading platform (70) located at the bottom of the rigid cavity (10), and a powder storage container (20) arranged above the powder spreading platform (70) and fixed to the top of the rigid cavity (10) for storing material powder (80), characterized in that: The pulse-type powder quantitative supply device further comprises an opening and closing unit (30), a discharging unit (40) and a pulse control unit (50); the powder storage container (20) comprises a powder storage cavity (21); the opening and closing unit (30) is arranged inside the powder storage container (20) and below the powder storage cavity (21); the discharging unit (40) is located between the powder storage cavity (21) and the opening and closing unit (30); the discharging unit (40) comprises a discharge port (41) connected to the powder storage cavity (21); the opening and closing unit (30) comprises an air cavity shell (31); The pulse control unit (50) is connected to the opening and closing unit (30) and is capable of controlling the opening and closing unit (30) to be alternately in an open state or a closed state, and is configured as follows: The time t during which the opening and closing unit (30) is in the open state satisfies: , so that the material powder (80) in a consistent state can fall onto the powder spreading platform (70) through the discharge port (41) to form a target powder spreading surface, s is the distance from the discharge port (41) to the lower surface of the air cavity shell (31), a is the acceleration, and the value is 9.8m / s 2 ; The time during which the opening and closing unit (30) is in the closed state is determined by the time required for the material powder (80) in the powder storage chamber (21) to be blocked above the opening and closing unit (30) and to be stationary.

2. The pulse type powder quantitative feeding device according to claim 1, characterized in that: The air cavity shell (31) is arranged on the inner wall of the powder storage container (20); when the opening and closing unit (30) is in a closed state, the closed portion of the air cavity shell (31) is in surface contact; when the opening and closing unit (30) is in an open state, the air cavity shell (31) forms an opening (32), wherein the size of the opening (32) is larger than the size of the discharge port (41).

3. The pulse type powder quantitative feeding device according to claim 2, characterized in that: The pulse control unit (50) comprises a controller (51), an air compressor (52), a positive-negative pressure converter (53) and a three-way electrically controlled air valve (54), wherein the three-way electrically controlled air valve (54) is respectively connected to the air compressor (52), the positive-negative pressure converter (53) and the air cavity housing (31), the positive-negative pressure converter (53) is connected to the air cavity housing (31), and the controller (51) is electrically connected to the three-way electrically controlled air valve (54).

4. The pulse type powder quantitative feeding device according to claim 3, characterized in that: The pulse-type powder quantitative supply device further comprises a valve unit (60) arranged at the bottom of the powder storage container (20), the valve unit (60) comprising a baffle (61) hinged at one end to the side wall of the powder storage container (20), an elastic element (62) respectively arranged at two ends on the baffle (61) and the inner wall of the powder storage container (20), and a driving cylinder (63) respectively arranged at two ends on the baffle (61) and the inner wall of the powder storage container (20), wherein the driving cylinder (63) is connected to the air compressor (52).

5. The pulse type powder quantitative feeding device according to claim 4, characterized in that: The pulse control unit (50) further includes an electromagnetic valve (64), which is arranged between the driving cylinder (63) and the air compressor (52), and the electromagnetic valve (64) is electrically connected to the controller (51).

6. The pulse type powder quantitative feeding device according to any one of claims 1 to 5, characterized in that: The discharge unit (40) comprises a supporting protrusion (42) and a discharge support plate (43) arranged on the supporting protrusion (42); the discharge port (41) is arranged on the discharge support plate (43).

7. The pulse type powder quantitative feeding device according to claim 6, characterized in that: The discharging unit (40) further includes a position-limiting seal (44), and the discharging support plate (43) is arranged between the supporting protrusion (42) and the position-limiting seal (44).

8. The pulse type powder quantitative feeding device according to claim 7, characterized in that: The limiting seal (44) comprises a limiting hole formed on the side wall of the powder storage container (20) and a sealing member detachably and sealingly connected to the limiting hole and partially protruding from the inner wall of the powder storage container (20).

9. The pulse type powder quantitative feeding device according to claim 6, characterized in that: The discharge port (41) is a rectangular hole.

10. A pulse powder quantitative supply method, which uses the pulse powder quantitative supply device according to any one of claims 1 to 9, characterized in that: The method comprises: Sending a pulse control signal through a pulse control unit (50) to control the opening and closing unit (30); and In response to the pulse control signal sent by the pulse control unit (50), the opening and closing unit (30) is alternately in an open state or a closed state.

11. The pulse powder quantitative supply method according to claim 10, wherein: The step of sending a pulse control signal through the pulse control unit (50) to control the opening and closing unit (30) further includes the steps of: Sending a pulse control signal through the controller (51) to control the three-way electric-controlled gas valve (54) to alternately connect and close; and The three-way electrically controlled air valve (54) responds to the pulse control signal to control the positive and negative pressure converter (53) to alternately be in an inflating state or an exhausting state. When the positive and negative pressure converter (53) is in the inflating state, the opening and closing unit (30) can be controlled to be in a closed state; when the positive and negative pressure converter (53) is in the exhausting state, the opening and closing unit (30) can be controlled to be in an open state.

12. The pulse powder quantitative supply method according to claim 11, characterized in that: Before the step of sending a pulse control signal through the controller (51) to control the three-way electric-controlled gas valve (54) to alternately connect and close, the method further includes the following steps: A control signal is sent to the electromagnetic valve (64) via the controller (51), and the electromagnetic valve (64) controls the valve unit (60) to be in an operating state. When the valve unit (60) is in the operating state, the baffle (61) of the valve unit (60) is opened under the action of the driving cylinder (63).

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