CN111791483A

CN111791483A - Pulse type powder quantitative supply device and method thereof

Info

Publication number: CN111791483A
Application number: CN202010651085.5A
Authority: CN
Inventors: 庞伟; 俞红祥; 董胜男
Original assignee: Hangzhou Dedi Intelligent Technology Co ltd
Current assignee: Hangzhou Dedi Intelligent Technology Co ltd
Priority date: 2020-07-08
Filing date: 2020-07-08
Publication date: 2020-10-20

Abstract

The invention provides a pulse type powder quantitative supply device and a method thereof, the device comprises a rigid cavity, an opening and closing unit, a pulse control unit and a discharging unit, a powder spreading platform positioned at the bottom of the rigid cavity and a powder storage container which is arranged above the powder spreading platform and fixed at the top of the rigid cavity and used for storing material powder, the powder storage container is provided with a powder storage cavity, the opening and closing unit is arranged in the powder storage container and positioned below the powder storage cavity, the discharging unit is positioned between the powder storage cavity and the opening and closing unit, the discharging unit is provided with a discharging hole which is communicated with the powder storage cavity, the pulse control unit is connected with the opening and closing unit and can control the opening and closing unit to be alternately in an opening state or a closing state, when the opening and closing unit is in the opening state, the material powder can fall onto the powder spreading platform through the discharging hole to form a target powder spreading surface, the material powder is blocked above the opening and closing unit, and the device has the characteristics of high powder discharging speed and controllable powder supply amount.

Description

Pulse type powder quantitative supply device and method thereof

Technical Field

The invention relates to the field of 3D printing, in particular to a pulse type powder quantitative supply device and a pulse type powder quantitative supply method.

Background

With the continuous improvement of the performance of the 3D printing equipment, the 3D printing process technologies and equipment of different types tend to be improved continuously, so that more and more materials with different materials and physical forms can be applied to the 3D printing equipment, and more diversified choices are provided for the progress and development of various industries. Different types of printing processes are determined by the types and forms of materials used in the corresponding processes, and from the perspective of material forms, solid wires (hot melt extrusion process, abbreviated as FDM), solid powder (hot melt bonding, abbreviated as SLS, hot melt bonding, abbreviated as SLM, direct metal deposition, abbreviated as DMD), liquid materials (three-dimensional light curing molding, abbreviated as SLA) and the like are correspondingly provided. Aiming at the solid powder material, a laser galvanometer two-dimensional scanning or ink-jet printing process is used in a processing mode, the capability similar to plane two-dimensional processing can be obtained, the printing efficiency is extremely high, the adaptability of the powder material on the forming principle is relatively wide, such as hot melt adhesion (SLS), hot melt bonding (SLM) and chemical reaction adhesion (ink-jet sand mold printing), therefore, the powder material 3D printing process also has a relatively wide application range in application, and has increasingly wide application in the fields of personal consumption, design prototype verification, industrial batch production and the like, wherein hot melt bonding (SLM) process equipment has relatively high precision and structural performance due to the formed part, and has wide application in the fields of aerospace, medical treatment and the like.

On the other hand, in the additive manufacturing equipment using the powder material, the existing powder material quantitative supply, uniform powder spreading in the powder bed equipment and the like limit the further improvement of the performance of the equipment due to the technical scheme of conveying the powder material in the equipment. Powder supply modes of powder bed equipment such as hot melt bonding (SLS) and hot melt bonding (SLM) are divided into upper powder supply and lower powder supply, and the upper powder supply mode has wide application in hot melt bonding (SLS) and hot melt bonding (SLM) equipment due to the advantages of compact structure, capability of realizing external continuous powder supply and the like. The upper powder feeding mode needs to realize two main functions, one is quantitative powder supply, the other is that the distribution of the powder on one side of the powder bed is matched with the powder quantity distribution required by the powder bed, and the two functions ensure the sufficient powder supply required by laying a layer of powder and simultaneously avoid much waste of residual powder. The existing method for quantitatively supplying powder is to use a servo motor to drive a powder supply gear to rotate and use a gear groove to realize quantitative powder supply, the gear mounting structure in the method is complex, the powder discharging speed is low, the powder clamping and leaking phenomena are easy to occur, and meanwhile, the powder quantity distribution after powder supply is matched with the shape of a powder bed under the condition that the printing breadth is continuously increased, if no effective corresponding scheme is available, the powder cannot be fully utilized, and the utilization efficiency of the powder is reduced.

At present, a pulse type powder quantitative supply method which is high in powder discharging speed, good in powder supply breadth adaptability and controllable in powder supply quantity distribution is still lacked for powder supply of hot melt bonding (SLS) and hot melt bonding (SLM) equipment.

Disclosure of Invention

In view of the above, it is desirable to provide a pulse type powder quantitative supply device and method thereof, which has the characteristics of fast powder discharging speed and controllable powder supply amount and distribution of powder supply.

The invention provides a pulse type powder quantitative supply device which comprises a rigid cavity, a powder spreading platform positioned at the bottom of the rigid cavity, a powder storage container which is arranged above the powder spreading platform and fixed at the top of the rigid cavity and used for storing material powder, an opening and closing unit, a pulse control unit and a discharging unit, wherein the powder storage container is provided with a powder storage cavity; when the opening and closing unit is in an opening state, 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 a closing state, the material powder is blocked above the opening and closing unit.

So set up, send the pulse control signal through the pulse control unit and open and close with the turn of control unit that opens and shuts in turn to when realizing being in the open mode, can spread the material powder under the action of gravity and spill on spreading the powder platform, when being in the closed condition, close the powder process of spreading of material powder, so that the material powder that is in discharge gate position of ejection of compact unit tends to the unanimous state, when being in the open mode with the unit that opens and shuts next time, spreads the powder. The pulse control unit can control the time of single pulse and combine the size of discharge gate, can realize the quantitative control to the powder supply volume and have the fast characteristics of powder outlet speed.

In one embodiment of the invention, the opening and closing unit comprises an air cavity shell arranged on the inner wall of the powder storage container, and 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 opening state, the air cavity shell forms an opening, wherein the size of the opening is larger than that of the discharge hole.

So set up, when the unit that opens and shuts is in the open mode, the air cavity casing can not influence the powder process of spreading of material powder, and in addition, the air cavity casing can be in the closure state under the gas filled state, and when in the closure state, the closure mode of face contact has avoided the material powder to drop on spreading the powder platform and has realized the ration under the single pulse material powder better.

In an embodiment of the present invention, the pulse control unit includes a controller, an air compressor, a positive-negative pressure converter and a three-way electric control air valve, the three-way electric control air valve is respectively communicated with the air compressor, the positive-negative pressure converter and the air cavity housing, the positive-negative pressure converter is communicated with the air cavity housing, and the controller is electrically connected to the three-way electric control air valve.

So set up, can aerify or bleed the air cavity casing that the opposition of unit that opens and shuts formed, realize the control to the state of opening and shutting of unit, in addition, the controller can control the time of pulse and set for, can further adjust the accurate control of single pulse in-process to the ration.

In an embodiment of the invention, the pulse type powder quantitative supply device further comprises a valve unit arranged at the bottom of the powder storage container, the valve unit comprises a baffle plate with one end hinged to the side wall of the powder storage container, an elastic element with two ends respectively arranged on the baffle plate and the inner wall of the powder storage container, and a driving cylinder with two ends respectively arranged on the baffle plate and the inner wall of the powder storage container, and the driving cylinder is communicated with the air compressor.

With the arrangement, the valve unit can charge air into the driving cylinder when the device provided by the invention is started, so that the baffle plate of the valve unit is opened relative to the powder storage container, and the powder is supplied to the powder spreading platform when the opening and closing unit is in an opening state. When the device provided by the invention stops running, the gas in the driving cylinder is pumped out, and the bottom opening of the powder storage container is sealed by the baffle under the action of the elastic element, so that the powder storage container is sealed, and the material powder is prevented from falling onto the powder spreading platform.

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

So set up, through the setting of electromagnetism pneumatic valve, can control valve unit better.

In one embodiment of the invention, the discharging unit comprises a supporting protrusion arranged inside the powder storage container, and a discharging supporting plate arranged on the supporting protrusion, and the discharging port is arranged on the discharging supporting plate.

So set up, can solve the problem of changing ejection of compact backup pad, change different ejection of compact backup pads and can realize having not unidimensional discharge gate, realize the regulation to single pulse powder output. The ejection of compact backup pad can be under the gravity pressure of material powder, fix on the support arch, and when the ejection of compact backup pad of not unidimensional needs to be changed, can conveniently take out the ejection of compact backup pad again from the support arch top.

In one embodiment of the invention, the discharging unit further comprises a limit sealing element, and the discharging supporting plate is arranged between the supporting protrusion and the limit sealing element.

So set up, in order to prevent that the ejection of compact backup pad from opening and shutting the unit and changing state process (including from open mode to closed state, perhaps from closed state to open mode), can receive the ascending power of unit that opens and shuts, lead to ejection of compact backup pad vibration or removal, be provided with spacing sealing member in the top of ejection of compact backup pad.

In one embodiment of the invention, the limiting sealing member comprises a limiting hole formed on the side wall of the powder storage container and a sealing member which is detachably and hermetically connected with the limiting hole and partially protrudes out of the inner wall of the powder storage container.

So set up, through the setting of spacing hole and sealing member, can dismantle more conveniently to the realization is to the change of ejection of compact backup pad.

In one embodiment of the invention, the discharge hole is a rectangular hole.

So set up the discharge gate into the rectangular hole, because the length of rectangular hole is not less than the length of shop's powder platform, the width of different rectangular holes will influence the play powder volume in the unit interval, and the width is relatively wider, and it is more to go out the powder volume, sets up the discharge gate into regular rectangle, can guarantee that the single goes out the powder and is even on length direction, goes out the powder back through many times pulse, and the distribution of total material powder is also even.

The invention also provides a pulse powder quantitative supply method, which adopts the pulse powder quantitative supply device, and the method comprises the following steps:

the pulse control unit sends out a pulse control signal to control the opening and closing unit;

responding to a pulse control signal sent by the pulse control unit, and enabling the opening and closing unit to be in an opening state or a closing state alternately; when the opening and closing unit is in an opening 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 a closing state, the material powder is blocked above the opening and closing unit.

In one embodiment of the present invention, the step of sending out the pulse control signal by the pulse control unit for controlling the opening and closing unit further comprises the steps of:

sending a pulse control signal through a controller to control the three-way electric control air valve to be alternately communicated and closed;

the three-way electric control air valve responds to the pulse control signal and controls the positive-negative pressure converter to be alternately in an inflation state or an air extraction state, and when the positive-negative pressure converter is in the inflation state, the opening-closing unit can be controlled to be in a closing state; when the positive and negative converters are in the air exhaust state, the opening and closing unit can be controlled to be in the opening state.

In one embodiment of the present invention, before the step of sending a pulse control signal through the controller to control the three-way electric control air valve to be alternately communicated and closed, the method further comprises the steps of:

and sending a control signal to the electromagnetic air valve through the controller, wherein the electromagnetic air valve controls the valve unit to be in a working state, and when the control valve unit is in the working state, a baffle of the valve unit is opened under the action of the driving cylinder.

Drawings

Fig. 1 is a schematic structural diagram of a pulse type powder quantitative supply device according to the present invention.

Fig. 2 is a schematic structural diagram of the pulse type powder quantitative supply device according to the above embodiment of the present invention when not in operation.

Fig. 3 is a schematic structural diagram of the pulse type powder quantitative supply device according to the above embodiment of the present invention when the opening and closing unit is in an open state.

Fig. 4 is a schematic structural diagram of the pulse type powder quantitative supply device according to the above embodiment of the present invention, in which the opening and closing unit is in a closed state and the valve unit is in an open state.

Fig. 5 is a schematic block diagram illustrating the connection between the controller of the pulse type powder quantitative supply device and other devices according to the above embodiment of the present invention.

10. A rigid cavity; 20. a powder storage container; 21. a powder storage cavity; 30. an opening and closing unit; 31. an air cavity housing; 32. opening the opening; 40. a discharging unit; 41. a discharge port; 42. a support boss; 43. a discharging support plate; 44. a limiting sealing element; 50. a pulse control unit; 51. a controller; 52. an air compressor; 53. a positive-negative voltage converter; 54. a three-way electric control air valve; 60. a valve unit; 61. a baffle plate; 62. an elastic element; 63. a drive cylinder; 64. an electromagnetic gas valve; 65. sealing gaskets; 70. a powder laying platform; 80. and (3) material powder.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

It will be understood that when an element is referred to as being "mounted on" another element, it can be directly mounted on the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Fig. 1 is a schematic structural diagram of a pulse type powder quantitative supply device according to an embodiment of the present invention. The invention provides a pulse type powder quantitative supply device which is used for quantitatively supplying powder to printing equipment. The invention provides a pulse type powder quantitative supply device which can be used for supplying material powder for hot melt adhesive bonding (SLS) or hot melt bonding (SLM) equipment and has the characteristics of high powder discharging speed, good adaptability of powder supply breadth and controllable powder supply distribution. In the present invention, the material powder refers to toner powder.

As shown in fig. 1 and 3, the pulse type powder quantitative supply device provided by the present invention includes 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 disposed above the powder spreading platform 70 and fixed on the powder storage container 20 at 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 for storing material powder 80. The opening and closing unit 30 is arranged in the powder storage container 20 and located 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 is provided with a discharging hole 41, the discharging hole 41 is communicated with the powder storage cavity 21 so that the material powder 80 located in the powder storage cavity 21 can fall onto the powder spreading platform 70 through the discharging hole 41, and 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 opening state or a closing 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 discharge port 41 to form 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, and the pulse control unit 50 sends out a pulse control signal to control the opening and closing of the opening and closing unit 30 alternately, so that the material powder 80 can be spread on the powder spreading platform 70 under the action of gravity when the opening and closing unit 30 is in the closed state, and the powder spreading process of the material powder 80 is closed when the opening and closing unit 30 is in the closed state, so that the material powder 80 at the discharge port 41 of the discharge unit 40 tends to be in a consistent state, and powder spreading is performed when the opening and closing unit 30 is in the open state next time. The pulse control unit 50 can control the time of a single pulse and combine with the size of the discharge hole 41, can realize quantitative control of the powder supply amount and has the characteristic of high powder discharging speed. It should be noted that the term "pulse type" herein means that the opening and closing unit 30 is alternately in the open state and the closed state. The time of the single pulse can be set by the pulse control unit 50, and the time of the single pulse is equal to the time of maintaining the one-time open state plus the time of maintaining the one-time closed state.

As shown in fig. 2, the opening and closing unit 30 may include an air cavity housing 31 disposed on an inner wall of the powder storage container 20, and when the opening and closing unit 30 is in a closed state, a closed portion of the air cavity housing 31 is in surface contact; when the opening and closing unit 30 is in an open state, the air cavity housing 31 forms an opening 32, wherein the size of the opening is larger than that of the discharge port 41, so that the material powder 80 does not contact the air cavity housing in the powder laying process of the material powder 80. The air cavity shell 31 can be in a closed state in an inflated state, and in the closed state, the surface-to-surface contact closing mode better prevents the material powder 80 from falling onto the powder laying platform 70, and better realizes quantitative supply of the material powder 80 under single pulse. Preferably, the air cavity housing 31 can control the expansion and contraction of the volume thereof by positive pressure or negative pressure, so as to control whether the material powder 80 in the powder storage container 20 flows out, and the surface material of the air cavity housing 31 may have certain toughness and softness, so as to effectively block the flowing material powder 80. Specifically, after the air chambers at the two ends of the air chamber shell 31 are inflated, the air chambers are contacted and closed below the discharging unit 40, and two contact surfaces at the closed position have certain thickness and certain toughness. Even if the material powder 80 exists between the two closed surfaces after the closing, the surface material thereof is passively deformed in accordance with the shape of the powder, and the material powder 80 is fixed between the joining surfaces without affecting the closing of the whole of the two closed surfaces.

Of course, it will be understood by those skilled in the relevant art that in other embodiments of the present invention, the air chamber housing 31 may be provided in at least two, at least two air chamber housings 31 being oppositely disposed on the inner wall of the powder storage container 20.

In addition, on the uniformity problem of the whole opening and closing process of the opening and closing unit 30, except that the positive-negative pressure converter 53 can make the air cavity in the air cavity shell 31 expand or contract integrally in the process of inflating or exhausting, because the contact surface material of the air cavity shell 31 has certain toughness, the position expanded or contracted firstly can also drive the position beside to move, and then the uniformity of the opening and closing unit 30 in the opening and closing process is improved. In addition, according to the structure of the opening and closing unit 30 provided by the invention, the structure of the opening and closing unit 30 provided by the invention is simple, and the structure of the air cavity shell 31 has elasticity and has better adaptability to different materials of powder 80.

As shown in fig. 1 and fig. 2, in order to better control the air cavity housing 31 of the opening and closing unit 30 to be in the opening state and the closing state in a pulse manner, in an embodiment of the present invention, the pulse control unit 50 may include a controller 51, an air compressor 52, a positive/negative pressure converter 53 and a three-way electronic control air valve 54, the three-way electronic control air valve 54 is respectively communicated with the air compressor 52, the positive/negative pressure converter 53 and the air cavity housing 31, the positive/negative pressure converter 53 is communicated with the air cavity housing 31, the controller 51 is electrically connected to the three-way electronic control air valve 54, the controller 51 sends a pulse control signal to control the three-way electronic control air valve 54, and further controls the positive/negative pressure converter 53 to alternately inflate or deflate the air cavity housing 31 formed opposite to the opening and closing unit 30. The controller 51 can control the timing of the single pulse and can further adjust the precise control of the dosing during the single pulse. Here, the pulse control signal sent by the controller 51 may be understood that the controller 51 sends a command for controlling the alternate opening and closing of each channel of the three-way electronic control air valve 54 to realize the pulse inflation or air suction of the positive and negative pressure exchanger 53, so as to realize the pulse control of the opening and closing state of the opening and closing unit 30.

As shown in fig. 2, the discharging unit 40 includes a supporting protrusion 42 disposed inside the powder storage container 20, and a discharging supporting plate 43 disposed on the supporting protrusion 42, and the discharging hole 41 is disposed on the discharging supporting plate 43, and preferably, the discharging hole 41 is configured as a rectangular hole. Preferably, the discharge hole 41 is an elongated rectangular hole. Since the discharging support plate 43 is supported by the support protrusion 42, the length and width of the discharging support plate 43 can be adapted to the size of the powder storage container 20, so that the discharging support plate 43 can be just put into the powder storage container 20 and supported by the support protrusion 42.

Further, as shown in fig. 2, in order to prevent the discharging support plate 43 from being pressed by the opening and closing unit 30 during the process of changing the state of the opening and closing unit 30 (including the process of changing the opening and closing unit 30 from the open state to the closed state, or from the closed state to the open state), the discharging support plate 43 may move upwards, a limit sealing member 44 is disposed above the discharging support plate 43, and the discharging support plate 43 is disposed between the support protrusion 42 and the limit sealing member 44. Preferably, the position-restricting sealing member 44 includes a position-restricting hole formed in a side wall of the powder storage container 20 and a sealing member 65 detachably and sealingly coupled to the position-restricting hole and partially protruding from an inner wall of the powder storage container 20. Here, the stopper hole may be implemented as a screw hole, and the sealing member 65 may be implemented as a screw fitted to the screw hole. Therefore, the discharging support plate 43 of the discharging unit 40 provided by the invention can be replaced, and the distribution requirement of different material powders 80 can be constructed by changing the size of the discharging port 41 of the discharging support plate 43, so that the universality and the applicability of the device are improved.

As shown in fig. 3 and fig. 4, the opening and closing unit 30 of the pulse type powder quantitative supply device provided by the present invention is illustrated in an open state and a closed state, respectively. When the opening and closing unit 30 is in the open state, at least two opposite air cavity shells 31 form an opening 32, at this time, the opening 32 corresponds to the discharge port 41, and the material powder 80 in the powder storage cavity 21 can fall through the discharge port 41. 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.

Specifically, the pulse type quantitative powder supply provided by the invention has the following realization principle: because the pressure applied to the discharging support plate 43 installed in the powder storage container 20 is only influenced by the installation angle and the powder storage amount of the powder storage container 20, the external powder supply and storage links will not influence the pressure of the discharging unit 40 through design, for example, the powder is supplied to the powder storage container 20 through a transverse pipeline conveying manner. Therefore, at the moment when the opening and closing unit 30 under the discharging support plate 43 is opened, the pressure and gravity of the powder 80 of the same type at the discharging port 41 are stable and will not be affected by the external powder path state. After the opening and closing unit 30 is opened, the material powder 80 in or above the discharge port 41 of the discharge supporting plate 43 will first make a free-falling motion downward, and the material powder 80 below will flow downward, wherein the material powder 80 farther away from the discharge port 41 will not move in a free-falling manner and will be disturbed by the flowing of the material powder 80 in all directions. Therefore, since the size of the discharge hole 41 is fixed, the amount and distance of the material powder 80 falling within a certain time are stable, and the time of the single pulse, more specifically, the time of the single pulse, during which the opening and closing unit 30 maintains the open state and the closed state, is set by the controller 51, so as to ensure that the material powder 80 falling relatively close to the free-fall form is allowed to flow out, so that the material powder 80 in the free-fall form is stably separated.

The opening and closing unit 30 is ensured to be in an opening state or a closing state in a pulse mode with a certain frequency, so that the time point of the material powder 80 flowing out is always performed under the condition that the material powder 80 in the powder storage cavity 21 is static, and the state of the material powder 80 in the powder storage cavity 21 is the same when the air cavity shell 31 of the opening and closing unit 30 is opened every time. This is because the time for which the opening and closing unit 30 is kept in the open state is the same each time, and it can be determined that the powder discharge amount is constant in each open state. Therefore, the continuous pulse material powder 80 with the same powder discharging amount each time is obtained, the pulse control unit 50 controls the opening and closing unit 30 to continuously pulse and discharge the powder m times before the material powder 80 made of a certain material, then the total weight k of the material powder 80 is weighed, the weight of the single pulse discharged powder is obtained to be k/m, and the total powder discharging amount is controlled according to the powder discharging amount of the single pulse and the pulse powder discharging times in the using process of the device. Therefore, the pulse type powder quantitative supply device provided by the invention has the advantages that the consistency of the powder discharge is controllable, the stable powder discharge state is realized, the powder discharge is carried out in the state, the powder discharge amount is equal every time, and the accurate control of the powder discharge amount can be realized after the calibration of the total powder discharge amount and the pulse frequency of the newly used material powder 80 is carried out.

In addition, in order to better control the powder feeding speed and the uniform distribution of the material powder 80, the control of the powder feeding speed may be achieved by changing the width of the discharge hole 41, for example, the discharge hole 41 of the discharge supporting plate 43 is implemented as a rectangular hole, the length of the rectangular hole is ensured to be not less than the length of the target powder laying surface, the amount of the material powder 80 falling by the movement of the proximity free fall body is different according to different widths, and the time interval between the open state and the closed state of the opening and closing unit 30 is the same because the falling distance is the same, and the wider the width of the discharge hole 41 is, the faster the powder discharging speed is. The discharge port 41 is regular rectangular, so that the powder discharged in a single time is uniform in the length direction, and after the powder is discharged by multiple pulses, the material powder 80 is uniformly distributed. When the powder spreading surface is wider, the width of the opening port 32 of the corresponding opening and closing unit 30 is ensured to be not less than the width of the powder spreading surface, and when the air cavity shell 31 of the opening and closing unit 30 is filled with air to be in a closed state or pumped out air to be in an open state, the falling distance of the free falling object is 0.5 x at as long as the relation s of the time²Wherein a is acceleration and takes 9.8m/s²S is the distance from the discharge support plate 43 to the lower surface of the air cavity housing 31, and it is found that the time t for the opening and closing unit 30 to be in the open state and to be maintained is about √ (2s/a) seconds, the material powder 80 in the same state will fall onto the powder laying platform 70 during this time, and when the opening and closing unit 30 is in the closed state, the other falling material powder 80 will be blocked on the opening and closing unit 30 or fixed between the contact surfaces of the opposite air cavity housing 31, and the opening and closing unit 30 maintains the closed stateThe ground time is determined according to the time required for the material powder 80 in the powder storage chamber 21 to stand still. Particularly in the application of large-breadth powder laying, the device provided by the invention can be well expanded and adapted, and has higher stability and lower complexity compared with the traditional mode.

In addition, the pulse type powder quantitative supply device provided by the invention can improve the precision of single powder supply by adjusting the time of single pulse in order to improve the control of the powder supply speed and precision. For example, since the amount of powder close to the free fall is fixed, the time for which these powders fall is fixed; at this time, it is assumed that the time for the opening/closing unit 30 to maintain the closed/open state in a single pulse is t1, the fixed powder discharge amount is w1, and the adjustment time t1 is t2 (t 2< t1 is satisfied), so that the powder discharge amount per pulse can be adjusted to w2 (w 2< w1 at this time), and thus a smaller powder discharge amount per pulse can be realized, and the accuracy of the powder discharge amount control is improved.

As shown in fig. 1 to 4, in order to ensure that the material powder 80 does not flow downward after the device provided by the present invention is in a power-off standby state, the pulse type powder quantitative supply device further includes a valve unit 60 disposed at the bottom of the powder storage container 20, the valve unit 60 includes a baffle 61 having one end hinged to the sidewall of the powder storage container 20, an elastic element 62 having two ends disposed on the baffle 61 and the inner wall of the powder storage container 20, respectively, and a driving cylinder 63 having two ends disposed on the baffle 61 and the inner wall of the powder storage container 20, respectively, wherein the driving cylinder 63 is communicated with the air compressor 52. The valve unit 60 is capable of filling the driving cylinder 63 with gas when the apparatus provided by the present invention is activated, so as 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 as to supply powder to the powder spreading platform 70 when the opening and closing unit 30 is in the opened state. When the pulse type powder quantitative supply device stops operating, the gas in the driving cylinder 63 is pumped out, and under the action of the elastic element 62, the bottom opening of the powder storage container 20 is sealed through the baffle 61, so that the powder storage container 20 is sealed, and the material powder 80 is prevented from falling onto the powder laying platform 70. Preferably, the elastic element 62 may be embodied as a spring.

In other embodiments of the 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; a sealing gasket (not shown) may also be provided on the side wall of the powder reservoir 20 near the bottom opening to better seal the bottom opening. Of course, it will be understood by those skilled in the art that when the sealing gasket 65 is provided at one end of the baffle 61, it is provided at the end remote from the hinged connection of the baffle 61 and the powder reservoir 20 to effect that the sealing gasket 65 is used to seal the bottom opening of the powder reservoir 20. Therefore, when the device provided by the invention is powered off and shut down, the baffle 61 is pulled by the spring to keep the baffle in a closed state, the sealing gasket 65 is arranged at the closed position of the side wall of the baffle 61 and the powder storage container 20, the amount of the material powder 80 stored between the discharging support part and the pneumatic control valve unit 60 is small, most of the pressure of the material powder 80 in the whole powder box is borne by the discharging support plate 43, and most of the material powder 80 at the baffle 61 of the pneumatic control valve unit 60 is naturally accumulated, so that the sealing requirement of the material powder 80 in a standby state can be met.

In order to better perform automatic control of the valve unit 60, as shown in fig. 2 and 5, 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, and the electromagnetic valve 64 is electrically connected to the controller 51.

The invention also provides a pulse powder quantitative supply method aiming at the pulse powder quantitative working device, which comprises the following steps:

a pulse control signal is sent by the pulse control unit 50 for controlling the opening and closing unit 30;

the opening and closing unit 30 is alternately in an open state or a closed state in response to a pulse control signal from the pulse control unit 50.

In one embodiment of the present invention, in the step of sending a pulse control signal by the pulse control unit 50 for controlling the opening and closing unit 30, the method may further include the steps of:

sending a pulse control signal through the controller 51 to control the three-way electric control air valve 54 to be alternately communicated and closed;

the three-way electric control air valve 54 responds to the pulse control signal to control the positive-negative pressure converter 53 to be alternately in an inflation state or an air extraction state, and when the positive-negative pressure converter 53 is in the inflation state, the opening-closing unit 30 can be controlled to be in a closing state; when the positive-negative converter 53 is in the pumping state, the opening and closing unit 30 can be controlled to be in the open state.

In an embodiment of the present invention, before sending the pulse control signal through the controller 51 to control the three-way electronic control air valve 54 to alternately communicate and close, the method may further include the steps of:

the solenoid valve 64 controls the valve unit 60 to be in the working state by sending a control signal to the solenoid valve 64 through the controller 51, and the flapper 61 of the valve unit 60 is opened by the driving cylinder 63 when the control valve unit 60 is in the working state.

The specific embodiment of the pulse type powder quantitative supply method provided by the invention has been described in detail when the pulse type powder quantitative supply is described, and is not described herein again.

It should be understood by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as a limitation of the present invention, and that suitable changes and modifications of the above embodiments are within the scope of the claimed invention as long as they are within the spirit and scope of the present invention.

Claims

1. The utility model provides an pulsed powder ration feeding device, includes rigidity cavity (10), is located shop powder platform (70) of rigidity cavity (10) bottom and set up in shop powder platform (70) top just is fixed in store up powder container (20) that the top of rigidity cavity (10) is used for depositing material powder (80), its characterized in that, pulsed powder ration feeding device still including open and shut unit (30), ejection of compact unit (40) and pulse control unit (50), store up powder container (20) and have store up powder chamber (21), open and shut unit (30) set up in store up inside powder container (20) and be located store up the below in powder chamber (21), ejection of compact unit (40) are located store up powder chamber (21) with between open and shut unit (30), ejection of compact unit (40) have discharge gate (41), discharge gate (41) communicate in store up powder chamber (21), 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 in an opening state or a closing state alternatively; when the opening and closing unit (30) is in an opening state, the material powder (80) can fall onto the powder spreading platform (70) through the discharge hole (41) to form a target powder spreading surface, and when the opening and closing unit (30) is in a closing state, the material powder (80) is blocked above the opening and closing unit (30).

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

3. The pulse type powder quantitative supply device according to claim 2, wherein the pulse control unit (50) comprises a controller (51), an air compressor (52), a positive-negative pressure converter (53) and a three-way electric control air valve (54), the three-way electric control air valve (54) is respectively communicated with the air compressor (52), the positive-negative pressure converter (53) and the air cavity shell (31), the positive-negative pressure converter (53) is communicated with the air cavity shell (31), and the controller (51) is electrically connected with the three-way electric control air valve (54).

4. A pulse powder quantitative supply device according to claim 3, further comprising a valve unit (60) disposed at the bottom of the powder storage container (20), wherein the valve unit (60) comprises a baffle (61) having one end hinged to the sidewall of the powder storage container (20), an elastic element (62) having two ends disposed on the baffle (61) and the inner wall of the powder storage container (20), respectively, and a driving cylinder (63) having two ends disposed on the baffle (61) and the inner wall of the powder storage container (20), respectively, and the driving cylinder (63) is communicated with the air compressor (52).

5. The pulse type powder quantitative supply device according to claim 4, wherein the pulse control unit (50) further comprises an electromagnetic gas valve (64), the electromagnetic gas valve (64) is arranged between the driving cylinder (63) and the air compressor (52), and the electromagnetic gas valve (64) is electrically connected to the controller (51).

6. A pulse type powder quantitative supply device according to any one of claims 1 to 5, characterized in that the material unit (40) comprises a supporting protrusion (42) arranged inside the powder storage container (20), and a discharging supporting plate (43) arranged on the supporting protrusion (42), and the discharging port (41) is arranged on the discharging supporting plate (43).

7. The pulse type powder quantitative supply device according to claim 6, wherein the discharging unit (40) further comprises a limit sealing member (44), and the discharging support plate (43) is arranged between the support protrusion (42) and the limit sealing member (44).

8. A pulse type powder quantitative supply device according to claim 7, characterized in that the limit sealing member (44) comprises a limit hole formed on the side wall of the powder storage container (20) and a sealing member detachably and hermetically connected to the limit hole and partially protruding the inner wall of the powder storage container (20).

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

10. A pulse powder quantitative supply method using the pulse powder quantitative supply device according to any one of claims 1 to 9, the method comprising:

a pulse control signal is sent out through a pulse control unit (50) to control the opening and closing unit (30);

the opening and closing unit (30) is alternately in an opening state or a closing state in response to a pulse control signal sent by the pulse control unit (50).

11. The pulse powder quantitative supply method according to claim 10, wherein in the step of sending a pulse control signal for controlling the opening and closing unit (30) by the pulse control unit (50), further comprising the step of:

sending a pulse control signal through a controller (51) to control a three-way electric control air valve (54) to be alternately communicated and closed;

the three-way electric control air valve (54) responds to the pulse control signal and controls the positive-negative pressure converter (53) to be alternately in an inflation state or an air extraction state, and when the positive-negative pressure converter (53) is in the inflation state, the opening-closing unit (30) can be controlled to be in a closing state; when the positive-negative converter (53) is in the air-extracting state, the opening-closing unit (30) can be controlled to be in the opening state.

12. The pulse powder dosing method according to claim 11, further comprising, before the step of sending a pulse control signal through the controller (51) to control the three-way electronic control valve (54) to alternately communicate and close, the steps of:

and sending a control signal to an electromagnetic air valve (64) through a controller (51), wherein the electromagnetic air valve (64) controls the valve unit (60) to be in a working state, and when the valve unit (60) is controlled to be in the working state, a baffle (61) of the valve unit (60) is opened under the action of a driving cylinder (63).