CN105403484B - The measuring device and measuring method of a kind of powder fluidity and compressibility - Google Patents

Abstract

The invention discloses a powder fluidity and compressibility measurement device and a measurement method. The powder fluidity and compressibility measurement device of the invention includes a transparent box, a support plate, a motor, a rectangular box, a measuring cylinder, Motor II, rotating arm and thin-walled ring; the support plate and the motor are installed in the transparent box, the right end of the rectangular box is hinged to the right end of the support plate, and the left end of the rectangular box is connected to the motor through the rope I. A stirring device is provided, and a pressure sensor Ⅰ is provided on the right side wall of the rectangular box; the motor Ⅱ is connected to the thin-walled ring through a rotating arm; A pressure sensor II is provided, a microvibrator is provided on the outer wall of the measuring cylinder, and the motor, the motor II, the pressure sensor I, the microvibrator and the pressure sensor II are respectively connected with the center console. The invention has a simple structure and can measure the fluidity parameters and compressibility parameters characterizing the powder at different temperatures.

Description

A measuring device and measuring method for powder fluidity and compressibility

technical field

The invention belongs to the field of powder measurement, in particular to a measurement device and method for powder fluidity and compressibility.

Background technique

Additive manufacturing is commonly known as 3D printing manufacturing technology. This technology is rapidly changing people's traditional production methods and lifestyles. 3D printing manufacturing technology characterized by digitization, networking, personalization, and customization is believed to promote the first Three industrial revolutions. Among the 3D printing technology methods, 3D printing with selective laser sintering (SLS) is the most widely used. This technology completes the conveying and flattening of the powder through the powder spreading mechanism, the powder feeding mechanism and the roller, and then sinters layer by layer through the laser, and finally obtains the required printed items, and maintains a certain level throughout the process. temperature. In this process, whether the powder can be flattened is directly related to the fluidity of the powder. The better the fluidity, the higher the quality of the powder, and the higher the accuracy of the printed product quality.

Fluidity is an important indicator to measure the quality of powder spreading. At present, the parameters to measure the fluidity of powder mainly include angle of repose, outflow, particle size distribution and so on. In addition to the fluidity characterization, the compressibility of the powder is also an important measure. The compressibility is usually characterized by the ratio of the bulk density of the powder to the loose bulk density, that is, the Hausner ratio HR of the powder, that is

Existing devices for measuring powder flow measure a single parameter of powder at room temperature. In the process of 3D printing powder spreading, comprehensive consideration of the fluidity and compressibility of powder is of great significance to the improvement of powder spreading quality. It has a great influence; at the same time, the temperature is also an essential influencing factor in the powder spreading process.

However, most of the existing published technical materials or documents do not comprehensively consider the relevant characterization characteristics of the powder, and there is no corresponding device to measure the fluidity and compressibility of the powder, nor does it consider the influence of temperature on the fluidity and compressibility of the powder. There is no corresponding device to measure the fluidity and compressibility of powder at different temperatures.

Contents of the invention

In order to solve the above technical problems, the present invention provides a measuring device and measuring method for powder fluidity and compressibility with simple structure, convenient operation and low cost.

The technical solution adopted by the patent of the present invention is: a measuring device for powder fluidity and compressibility, including a transparent box, a support plate, a motor, a rectangular box, a measuring cylinder, a motor II, a rotating arm and a thin-walled ring; The support plate and the motor are installed in the transparent box, the right end of the rectangular box is hinged to the right end of the support plate, the left end of the rectangular box is connected to the motor through a rope I, a stirring device is provided in the rectangular box, and the right side wall of the rectangular box is There is a pressure sensor Ⅰ; the motor Ⅱ is installed on the transparent box, and the motor Ⅱ is connected with the thin-walled ring through the rotating arm; the measuring cylinder is set on the supporting platform corresponding to the right end of the rectangular box, between the measuring cylinder and the supporting platform There is a pressure sensor Ⅱ, the upper end of the measuring cylinder is flush with the bottom of the thin-walled ring, the outer wall of the measuring cylinder is provided with a microvibrator, the support table is set at the bottom of the transparent box, the motor, the motor Ⅱ, the pressure sensor Ⅰ, the microvibrator and the pressure sensor Ⅱ Connect with the center console respectively.

In the above-mentioned measuring device for powder fluidity and compressibility, a support frame with scale is installed vertically in the transparent box, and a scale is arranged on the support frame with scale. The runner I on the motor is connected, and the upper end of the rope I is connected on the runner I on the motor.

In the above-mentioned measuring device for powder fluidity and compressibility, a heating device, a temperature sensor I and an inert gas device are arranged in the transparent box, a temperature sensor II is arranged in the rectangular box, and the support plate An electric heater is arranged under the rectangular box, and the heating device, temperature sensor I, temperature sensor II, inert gas device and electric heater are respectively connected with the center console.

In the above-mentioned measuring device for powder fluidity and compressibility, the measuring cylinder and the supporting table are placed in the recovery cylinder.

A method for measuring powder fluidity and compressibility, the specific steps are as follows:

(1) Add powder into the rectangular box, cover the pressure sensor I on the right side wall of the rectangular box, start the heating device, make the temperature in the box reach the specified temperature, stop heating; start the inert gas device, and at the same time Start the electric heater and stirring device, when the temperature of the powder reaches the specified temperature, start the motor, the rope I and the rope II move synchronously, the left end of the rectangular box rises, the pressure sensor I receives the pressure of the continuously falling powder, and feeds back to the center console, The motor stops moving, and the rising height H of the left end of the rectangular box is measured through the ruler;

(2) Open the right end of the rectangular box through the center console, the powder flows into the measuring cylinder, when the powder exceeds the thin-walled ring, the center console controls the motor to reverse, the powder stops flowing in, start the motor II, and the rotating arm drives the thin-walled ring to rotate At the same time, the powder at the end of the measuring cylinder is also scraped. After the thin-walled ring is separated from the measuring cylinder, the motor II stops running, and the data fed back to the center console by the pressure sensor II is read; then, the _reverse rotation of the motor II is controlled by the center console. , when the thin-walled ring returns to the port position of the measuring cylinder, the motor II stops; the control motor rotates forward, and the powder flows into the measuring cylinder from the rectangular box again; when the powder exceeds the thin-walled ring, the control motor reverses; The powder starts to drop, the vibration of the micro vibrator stops after ten minutes, the starting motor II rotates forward, the rotating arm drives the thin-walled ring to rotate, and the powder at the end of the measuring cylinder is scraped again, after the thin-walled ring is separated from the measuring cylinder, the motor II stops running, read Take the data fed _back from the pressure sensor II to the center console.

(3) After measuring the data, use the formula and Calculate the angle of repose α and HR value.

Compared with prior art, the beneficial effect of the present invention is:

The invention has the advantages of simple structure, low cost and easy operation; the invention can measure the characteristic parameters of powder fluidity and compressibility at different temperatures, and lays an experimental foundation for studying the effect of temperature on powder spreading in the selective laser sintering process.

Description of drawings

Fig. 1 is a structural schematic diagram of a measuring device for powder fluidity and compressibility of the present invention.

In the figure, 1‐shaft, 2‐motor, 3‐rotor Ⅰ, 4‐rectangular box, 5‐stirring device, 6‐temperature sensor Ⅰ, 7‐pressure sensor Ⅰ, 8‐thin-walled ring, 9‐heating device, 10 ‐Inert gas device, 11‐rotating arm, 12‐motor Ⅱ, 13‐motor fixing frame, 14‐recovery cylinder, 15‐support table, 16‐microvibrator, 17‐pressure sensor Ⅱ, 18‐gauge cylinder, 19‐support frame , 20‐hinge, 21‐electric heater, 22‐auxiliary block, 23‐support frame with scale, 24‐support plate, 25‐temperature sensor Ⅱ, 26‐ruler, 27‐rope Ⅰ, 28‐rope Ⅱ, 29 ‐Runner Ⅱ, 30‐transparent box.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, the present invention comprises a measuring cylinder 18, a transparent box 30, a heating device 9, an inert gas device 10, a support plate 24, a rectangular box 4, a slider 11, a vibrator 16, a thin-walled ring 8, a rope I27, Motor 2, rope II 28, motor II 12, runner I 3, runner II 29 and scale 26. The heating device 9, the inert gas device 10, the support plate 24, the motor 2, and the motor II12 are installed in the transparent box body 30; in order to measure the temperature in the transparent box body 30, a temperature sensor I6 is also arranged in the transparent box body 30 .

The supporting plate 24 is arranged horizontally, and the rectangular box 4 is arranged on the supporting plate 24 , and the right end of the rectangular box 4 is hinged with the right end of the supporting plate 24 through a hinge 20 . The inner wall of the rectangular box 4 is provided with a temperature sensor II25, and the right side wall is provided with a pressure sensor I7. An electric heater 21 and an auxiliary block 22 are arranged below the rectangular box 4 on the support plate 24 . The rope I27 is wound on the runner I3, and the runner I3 is driven by the motor 2. One end of the rope I27 is fixed on the left end of the rectangular box 4 . The rope II28 is wound on the runner I3 and the runner II29, and the motor 2 drives the runner I3, and the runner II29 moves, thereby driving the rope II28 to move. One end of the rope II 28 is connected with the scale 26, the scale 26 is located on the support frame 23 with scale, and can slide on the support frame 23 with scale, and the support frame 23 with scale is vertically arranged in the transparent box 30. The ropes I27 and II28 are driven and pulled by the motor 2 to realize synchronous movement, so that the scale 26 can accurately measure the rising tilt height of the rectangular glass box. The right end of the measuring cylinder 18 corresponding to the rectangular box 4 is arranged on the supporting platform 15, a pressure sensor II 17 is arranged between the measuring cylinder 18 and the supporting platform 15, and a microvibrator 16 is installed on the outer wall of the measuring cylinder 18; In cylinder 14.

The motor II12 is supported by the motor holder 13, and the motor II12 is connected with the thin-walled ring 8 through the rotating arm 11; the rotating arm 11 can rotate in the horizontal plane; The motor 2, motor II12, pressure sensor I7, pressure sensor II17, temperature sensor I6, temperature sensor II25, microvibrator 16, heating device 9, inert gas device 10 and electric heater 21 are respectively connected to the center console.

The measuring method of powder fluidity and compressibility of the present invention, comprises the steps:

(1) After preparing the experimental measurement device, open the glass box 31, add powder into the rectangular box 4, cover the pressure sensor I7 on the right side wall of the rectangular box 4, close the box door, and start the heating device 9. After the temperature in the box reaches the specified temperature, stop the heating device 9, start the inert gas device 10, and start the heater 21 and the stirring device 5 at the same time, so that the powder in the rectangular box 4 is heated evenly. When the rectangular box 4 After the powder temperature reaches the specified temperature, start the motor 2, the rope I27, the rope II28 pass through the runner I3 and the runner II29 to realize synchronous movement, the left end of the rectangular box 4 rises, the pressure sensor I7 receives the pressure of the continuously falling powder, and feedbacks the central control platform, the motor 2 stops moving, and now the ruler measures the rising height H of the left end of the rectangular box 4.

(2) After measuring the rising height of the left end of the rectangular box 4, open the right end of the rectangular box 4 through the center console, and the powder flows into the measuring cylinder 18. When the powder exceeds the thin-walled ring 8, the center console controls the motor 2 to reverse, The powder stops flowing in, start the motor II12, the rotating arm 11 drives the thin-walled ring 8 to rotate, and at the same time scrapes the powder at the end of the measuring cylinder 18, after the thin-walled ring 8 is separated from the measuring cylinder 18, the motor II12 stops running, and the pressure sensor II17 reads the feedback to The data M on the center console _{is loose} ; then, the motor II 12 is controlled to reverse through the center console, and when the thin-walled ring 8 returns to the position of the measuring cylinder 18 port, the motor II 12 stops, and the motor 2 is controlled to rotate forward at this time, and the powder is released from the rectangular box 4 again. Flow into the measuring cylinder 18, when the powder in the measuring cylinder 18 exceeds the thin-walled ring 8, the control motor 2 reverses, the powder stops flowing in, the micro vibrator 16 is started, the powder in the measuring cylinder 18 drops, and the micro vibrator 16 vibrates for ten minutes Stop, start the motor II12 to rotate forward, the rotating arm 11 drives the thin-walled ring 8 to rotate, scrape off the powder at the end of the measuring cylinder 18, and after the thin-walled ring 8 is separated from the measuring cylinder 18, the motor II12 stops running, and the reading pressure sensor II17 is fed back to The data in the center console is M _tight .

(3) After measuring the data, use the formula and Calculate the angle of repose α and HR value.

According to the above steps, different temperatures can be set to measure the characteristic parameters of the fluidity and compressibility of the powder at different temperatures.

Claims (2)

1. the measuring device of a kind of powder fluidity and compressibility, it is characterized in that：Including transparent cabinet, support plate, motor, square Shape box, graduated cylinder, motor II, cursor and thin wall circular；The support plate and motor are installed in transparent cabinet, the square The right end of shape box and the right end of support plate are hinged, and the left end of rectangular box is connected by rope I with motor, and stirring is equipped with rectangular box Device, right side wall is equipped with pressure sensor I in rectangular box；The motor II is installed on transparent cabinet, and motor II passes through Cursor is connected with thin wall circular；The right end that the graduated cylinder corresponds to rectangular box is located in supporting table, graduated cylinder and supporting table it Between be equipped with pressure sensor II, graduated cylinder upper end is concordant with the bottom of thin wall circular, and the lateral wall of graduated cylinder is equipped with microseism device, support Platform is located at transparent cabinet bottom, and motor, motor II, pressure sensor I, microseism device and pressure sensor II connect with console respectively Connect；Supporting rack with a scale is equipped with the transparent cabinet vertically, supporting rack with a scale is equipped with scale, and scale connects with rope II Connect, rope II is connected around runner II with the runner I on motor, and the upper end of rope I is connected on the runner I on motor；It is described Transparent cabinet in be equipped with heating unit, temperature sensor I and inert gas installation, the rectangular box is interior to be equipped with temperature sensing Device II, the lower section of rectangular box is equipped with electric heater, heating unit, temperature sensor I, temperature sensor II, inertia in support plate Gas device and electric heater are connected with console respectively；The graduated cylinder and supporting table is placed in recovery tank.

2. the measuring method of a kind of powder fluidity and compressibility, comprises the following steps that：

（1）Powder is added in rectangular box, the pressure sensor I on right side wall in rectangular box is covered, starts heating unit, After the temperature in babinet is reached assigned temperature, stop heating；Start inert gas installation, while start electric heater and stirring Device, when powder temperature reaches assigned temperature, starts motor, rope I and rope II are synchronized with the movement, on the left end of rectangular box Rise, pressure sensor I is subject to keep falling the pressure of powder, feeds back console, motor stop motion, goes out square by tape measure The lifting height H of shape box left end；

（2）The right end of rectangular box is opened by console, powder is flowed into graduated cylinder, after powder exceeds thin wall circular, console Motor reversal is controlled, powder stops flow into, and starts motor II, cursor drives thin wall circular rotation, while has also struck off graduated cylinder The powder of port, after thin wall circular is separated with graduated cylinder, motor II is out of service, reads pressure sensor II and feeds back to console Data；Then, motor II is controlled to invert by console, when thin wall circular returns to graduated cylinder port position, motor II stops； Motor is controlled to rotate forward, powder is flowed into graduated cylinder from rectangular box again, after powder exceeds thin wall circular, controls motor reversal；Open Micro- device that shakes is moved, the powder in graduated cylinder is begun to decline, and micro- device that shakes stops after vibrating ten minutes, starts motor II and rotates forward, cursor band Dynamic thin wall circular rotation, has struck off the powder of graduated cylinder port again, and after thin wall circular is separated with graduated cylinder, motor II is out of service, Read the data that pressure sensor II feeds back to console；

（3）Survey after data, passed through formulaWithCalculate angle of repose α and HR value.