Weighing workstation and metering method

Abstract

The invention discloses a weighing workstation and a metering method, and belongs to the field of automatic control. Comprising three main parts, namely a core weighing part, a plurality of shielding covers, a weighing bottle and a conveying part. The core weighing component can reduce system errors through mutual correction of double sensors, can perform signal amplification on sample weight difference through a lever principle, and can perform long-term rapid correction on sensor fluctuation and lever deformation through an electromagnetic force balance principle. The precise weight of the sample can be obtained through a residual error minimization high-precision metering method. The high-precision weighing device is suitable for high-precision weighing of samples of food, medicines, health care products, traditional Chinese medicinal materials, agricultural products, environmental pollution and the like, and the samples can be sealed and transferred through the specially-made weighing bottle and the conveying belt; the problems that manual sample weighing is low in efficiency, original data has a fake space, the automation degree is low, and samples cannot be timely and properly stored in multiple inspection work in the prior art can be solved, and inspection automation can be achieved easily.

Description

Technical Field

[0001] The present invention relates to a weighing workstation and a high-precision measuring method, which belong to the fields of automatic control and sample pretreatment. The weighing workstation is suitable for all inspection and testing industries for high-precision weighing of samples such as food, medicine, health products, Chinese medicinal materials, agricultural products, and environmental pollution samples, and can seal and transfer samples in a timely manner. Background Art

[0002] 1. Industry needs and pain points

[0003] In traditional inspection work, samples need to be weighed manually. This operation has many pain points, such as low efficiency, inability to upload original data in a timely manner, room for fraud, low degree of automation, and inability to properly preserve samples in a timely manner, which is not conducive to the realization of inspection automation.

[0004] 2. Current status of existing equipment

[0005] At present, there is no automatic weighing workstation on the market at home and abroad that can be applied to a variety of samples such as food, medicine, health products, cosmetics, Chinese herbal medicines, agricultural products, etc. After checking the relevant patents and market research, it is found that the current electronic balance has a low degree of automation. Although there are devices that rely on the principle of electromagnetic force balance for weighing, there is no device that can use the mutual correction between dual sensors to obtain higher-precision weighing results. In addition, there is no high-precision weighing device specifically suitable for samples such as food, medicine, health products, Chinese herbal medicines, agricultural products, and environmental pollution samples. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a weighing workstation and a high-precision measuring method for sample weight.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A weighing workstation, comprising:

[0009] A weighing device for a weighing bottle comprises a weighing lever, a weighing lever bracket and a weighing lever horizontal adjustment mechanism; the weighing lever is arranged on the weighing lever bracket; the weighing lever horizontal adjustment mechanism is arranged at the proximal end of the weighing lever and is used to adjust the horizontal state of the weighing lever; a first pressure sensor is arranged at the contact position between the weighing lever horizontal adjustment mechanism and the proximal end of the weighing lever; a second pressure sensor is arranged at the lower end of the weighing lever bracket; a weighing support hinged to the weighing lever is arranged at the distal end of the weighing lever, and a weighing support center eye for embedding a weighing bottle is arranged at the upper end of the weighing support; a soft iron core is arranged at the lower end of the weighing support; a coil mounting column is arranged below the weighing support, and an electromagnetic coil is arranged in the coil mounting column; when the weighing support moves up and down, the soft iron core is inserted into the electromagnetic coil.

[0010] The weighing rod horizontal adjustment mechanism includes a core rotating shaft, a core rotating shaft motor and a first pressure sensor mounting arm; the core rotating shaft motor drives the core rotating shaft to rotate, the first pressure sensor mounting arm is arranged on the core rotating shaft, the first pressure sensor is arranged on the first pressure sensor mounting arm, and a first pressure sensor ball head is arranged on the first pressure sensor; the first pressure sensor ball head contacts the proximal end of the weighing lever.

[0011] The weighing rod horizontal adjustment mechanism also includes a core rotating shaft gear, a core rotating shaft pinion, a star nut and a dumbbell nut; the core rotating shaft gear is meshed with the core rotating shaft pinion; the core rotating shaft pinion is connected to the core rotating shaft motor; the dumbbell nut is arranged on the core rotating shaft gear; the star nut is meshed with the dumbbell nut; the star nut is arranged on the core rotating shaft.

[0012] The outer side of the star nut is four arc grooves; the dumbbell nut has two centrally symmetrical arc convex heads; the arc convex heads of the dumbbell nut are adapted to the arc grooves of the star nut, that is, because of their shapes, they are effectively constrained from rotating each other. The dumbbell nut is active and the star nut is driven.

[0013] It also includes: a weighing bottle conveying device, which is used for conveying the weighing bottle.

[0014] The weighing bottle conveying device comprises a conveying track and a conveying link sliding in the conveying track; the conveying link is formed by hingedly connecting the weighing bottle conveying joints.

[0015] The weighing bottle conveying device also includes a conveying section motor and a conveying section dial wheel. A conveying section limit ring higher than the plane of the weighing bottle conveying section is arranged on each weighing bottle conveying section; the conveying section motor drives the conveying section dial wheel to dial the conveying section limit ring, so that the weighing bottle conveying section 120 moves forward or backward in the horizontal direction.

[0016] It also includes multiple shielding covers, namely a core cover, an electromagnetic shielding cover, a buffer cover and a transmission cover.

[0017] The measurement method based on the weighing workstation includes:

[0018] Calibrate the weighing workstation, including periodic calibration and power-on calibration. Periodic calibration uses two standard weights to calculate the inherent electromagnetic force conversion coefficient α, which is stored in the instrument and fixed before the next periodic calibration. Power-on calibration calculates the latest slopes k1 and k2 of the signal F1 of the first pressure sensor, the signal F2 of the second pressure sensor and the change of the unit mass m.

[0019] Weigh the sample. Assume that the mass of the sample calculated by ΔF1 is W5a, and the mass of the sample calculated by ΔF2 is W5b. Then:

[0020]

[0021] Among them, the W5 correction value is the corrected sample mass.

[0022] ΔF1 and ΔF2 are:

[0023] ΔF1=W4×L4 / L3

[0024] ΔF2=2×W4×L4

[0025] Among them, W4 is the weight of the standard weight; L3 is the distance from the middle hinge point of the weighing lever to the near end; L4 is the distance from the middle hinge point of the weighing lever to the far end.

[0026] The weighing workstation of the present invention can be calibrated quickly and periodically by using standard weights and the electromagnetic force balance principle. This calibration can correct the slight fluctuation of the sensor signal conversion intensity and the slight deformation of the weighing lever caused by thermal expansion and contraction, so that the weighing workstation of the present invention can obtain high-precision results for a long time. The weighing workstation of the present invention can simulate the function of standard weights by generating magnetic force on ferromagnetic bodies through electromagnetic coils, and can be used for daily startup calibration. The weighing workstation of the present invention is fast in weighing and convenient in use; it adopts a high-precision weighing and metering method, and the result is highly accurate; it adopts the lever principle, and the pressure sensor signal is amplified by different arm lengths, which can improve the sensitivity of weighing; it adopts a laser transceiver to accurately confirm that the weighing lever reaches the horizontal weighing position to ensure that the movable parts are in the correct position; it adopts multiple weighing levers for weighing at the same time and multiple transmission nodes are connected to each other, which can realize the rapid weighing of large batches of samples and significantly improve the inspection efficiency; it adopts a specially designed weighing bottle, which can quickly seal the sample and conveniently transfer it to other inspection equipment; it adopts two high-precision measurement correction methods, namely "minimum residual method" and "minimum slope difference method", which can make the signals of two sensors correct each other and obtain more precise weighing data. The weighing workstation of the present invention is suitable for high-precision weighing of samples such as food, medicine, health products, Chinese medicinal materials, agricultural products, environmental pollution samples, etc. in all inspection and testing industries. The present invention provides a fast, universal, modular weighing tool and high-precision measurement method for realizing inspection automation.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention is an important, universal, modular functional device in the field of inspection automation.

[0029] 2. The present invention has a compact design and high weighing efficiency. It adopts the electromagnetic force balance principle to simulate standard weights and can achieve rapid correction. The high-precision measurement method provided takes advantage of dual sensors. It adopts an optimized length of force arm and uses lever balance to amplify the signal of the sample weight. A laser transceiver is used to accurately confirm the position of the weighing lever, and the result is more accurate.

[0030] 3. The device of the present invention has good applicability and can be applied to a variety of samples such as food, medicine, health products, cosmetics, Chinese medicinal materials, agricultural products, etc.; all accessories are easy to disassemble and assemble, and its modular design allows for flexible combination of inspection automation systems. Samples can be sealed in time and are easy to store and transfer.

[0031] Fourth, the present invention adopts the "minimum residual method" and "minimum slope difference method" to perform high-precision calibration on the weighing workstation; it adopts a dual pressure sensor and a sample measurement method in which the two sensors correct each other, which can achieve high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the overall structural diagram of the present invention;

[0033] Figure 2 It is a structural diagram of the weighing core part of the present invention;

[0034] Figure 3 It is a schematic diagram of the installation of the base and the protective cover of the present invention;

[0035] Figure 4 to Figure 7 It is a schematic diagram of the operation of the weighing core part of the present invention;

[0036] Figure 8 It is a side view of the weighing core part of the present invention;

[0037] Fig. 9 It is a schematic diagram of the weighing lever principle of the present invention;

[0038] Fig.10 It is a schematic diagram of the weighing support and center correction of the present invention;

[0039] Fig.11 It is a schematic diagram of an attachment of the present invention;

[0040] Fig.12 It is a schematic diagram of the electromagnetic force calculation principle of the present invention;

[0041] Fig.13 It is a schematic diagram of the electromagnetic force calculation principle near the internal axis of the current-carrying straight solenoid of the present invention;

[0042] Wherein: 1. base, 2. core cover fixing platform, 3. core shaft, 4. core shaft gear, 5. core shaft motor, 6. core shaft motor shaft, 7. core shaft pinion, 8. first baffle of base, 9. second baffle of base, 10. electromagnetic shielding cover fixing platform, 11. coil mounting column, 12. electromagnetic coil, 13. first pressure sensor mounting arm, 14. first pressure sensor, 15. first pressure sensor ball head, 16. first pressure sensor wire, 17. second pressure sensor mounting column, 18. weighing lever bracket, 19. second pressure sensor, 20. weighing lever support shaft, 21. weighing lever, 22. weighing lever tilting hole, 23. weighing lever lifting ring, 24. weighing support, 25. weighing support support shaft, 26. core shaft mounting column, 27. star nut, 28. dumbbell nut, 29. weighing support mounting hole, 30. weighing support center eye, 31. weighing Support weight rod, 32. soft iron core, 33. laser reflection platform, 34. weighing support vent, 35. laser transceiver, 36. transmitting optical path, 37. receiving optical path, 100. core cover, 101. core cover shaft groove, 102. core cover lever door, 103. buffer cover, 104. buffer cover lever door, 105. conveying cover, 106. conveying cover sample hole, 107. conveying cover lever door, 108. electromagnetic shielding cover, 109. electromagnetic screen Shielding coil hole, 110. weighing bottle, 111. weighing bottle foot, 112. weighing bottle cap pad, 113. weighing bottle cap, 114. weighing bottle body, 120. weighing bottle conveying section, 121. conveying section ear, 122. conveying section ear hole, 123. conveying section connecting shaft, 124. conveying section limiting ring, 125. conveying section center window, 130. conveying track, 131. standard weight, 132. conveying section motor, 133. conveying section dial wheel. DETAILED DESCRIPTION

[0043] The present invention will be described in detail below in conjunction with the accompanying drawings:

[0044] The invention provides a weighing workstation and a high-precision measuring method.

[0045] like Figure 1 As shown, a weighing workstation comprises:

[0046] The weighing device for a weighing bottle comprises a weighing lever 21, a weighing lever bracket 18 and a weighing lever horizontal adjustment mechanism; the weighing lever 21 is arranged on the weighing lever bracket 18; the weighing lever horizontal adjustment mechanism is arranged at the proximal end of the weighing lever 21, and is used to adjust the horizontal state of the weighing lever; a first pressure sensor 14 is arranged at the proximal contact position between the weighing lever horizontal adjustment mechanism and the weighing lever 21; a second pressure sensor 19 is arranged at the lower end of the weighing lever bracket 18; a weighing support 24 hinged to the weighing lever 21 is arranged at the distal end of the weighing lever 21, and a weighing support center eye 30 for embedding a weighing bottle is arranged at the upper end of the weighing support 24; a soft iron core 32 is arranged at the lower end of the weighing support 24; a coil mounting column 11 is arranged below the weighing support 24, and an electromagnetic coil 12 is arranged in the coil mounting column 11; when the weighing support 24 moves up and down, the soft iron core 32 is inserted into the electromagnetic coil 12.

[0047] The weighing rod horizontal adjustment mechanism includes a core rotating shaft 3, a core rotating shaft motor 5 and a first pressure sensor mounting arm 13; the core rotating shaft motor 5 drives the core rotating shaft 3 to rotate, the first pressure sensor mounting arm 13 is arranged on the core rotating shaft 3, the first pressure sensor 14 is arranged on the first pressure sensor mounting arm 13, and a first pressure sensor ball head 15 is arranged on the first pressure sensor 14; the first pressure sensor ball head 15 contacts the proximal end of the weighing lever 21.

[0048] The weighing rod horizontal adjustment mechanism also includes a core shaft gear 4, a core shaft pinion 7, a star nut 27 and a dumbbell nut 28; the core shaft gear 4 is meshed with the core shaft pinion 7; the core shaft pinion 7 is connected to the core shaft motor 5, and the dumbbell nut 28 is arranged on the core shaft gear 4; the star nut 27 is meshed with the dumbbell nut 28; the star nut 27 is arranged on the core shaft 3. Figure 4-5 As shown. The core shaft motor 5 is combined with a core shaft pinion 7 and a core shaft gear 4 to precisely control the rotation of the dumbbell nut 28 installed in the center of the core shaft gear 4. The dumbbell nut 28 is combined with the star nut 27 to control the rotation of the core shaft 3. The core shaft gear 4 rotates counterclockwise, which will drive the core shaft 3 to rotate clockwise, causing the first pressure sensor mounting arm 13 fixed thereon to rotate clockwise, buckling the first pressure sensor ball head 15 into the weighing lever tilting hole 22, so that the other end of the weighing lever 21 is tilted, and the weighing support center eye 30 on the top of the weighing support 24 will cover the weighing bottle foot 111 at the bottom of the weighing bottle 110, lift the weighing bottle 110, and separate from the conveying section limit ring 124. The conveying section center window 125 provides space for the weighing support 24 and the weighing bottle foot 111.

[0049] The outer side surface of the star nut 27 is formed with four arc grooves; the dumbbell nut 28 has two centrally symmetrical arc convex heads; the arc convex heads of the dumbbell nut 28 are adapted to the arc grooves of the star nut 27;

[0050] like Figure 5 As shown, when the two arc convex heads of the dumbbell nut 28 are arranged vertically at 0°, the arc groove of the star nut 27 can be limited at this time, thereby limiting the rotation of the core shaft 3, so that the first pressure sensor 14 presses the weighing lever 21 downward, so that the weighing lever 21 maintains a horizontal position, i.e., a measuring position, and then the weighing support 24 at the other end of the weighing lever 21 passes upward through the center window 125 of the conveying section, lifts up the weighing bottle 110, and separates the weighing bottle 110 from the weighing bottle conveying section 120, ensuring that the weight of the weighing bottle and the internal sample are all loaded onto the weighing lever 21.

[0051] When the two arc convex heads of the dumbbell nut 28 are gradually rotated counterclockwise by 0 to 30 degrees or clockwise by 0 to 60 degrees ( Figure 4 As shown in the figure, the arc groove of the star nut 27 is gradually not restricted by the two arc protrusions of the dumbbell nut 28, and the first pressure sensor 14 no longer generates a compressive force on the weighing lever 21. The weighing lever 21 is acted upon by natural gravity so that the end of the first pressure sensor 14 is tilted upward, while the weighing support 24 at the other end passes downward through the central window 125 of the conveying section, and the contact surface with a larger diameter at the bottom contacts the annular platform at the top of the coil mounting column 11, so that the weight of the weighing bottle and the internal sample is loaded onto the annular platform at the top of the coil mounting column 11.

[0052] When the two arc convex heads of the dumbbell nut 28 gradually rotate counterclockwise by 30°, the four convex teeth of the star nut 27 will be driven by the core shaft 3 under the action of gravity to rotate at a certain angle. At this time, when the two arc convex heads of the dumbbell nut 28 gradually rotate clockwise by 0-30°, the star nut 27 can be gradually rotated counterclockwise, and the core shaft 3 is also driven to gradually rotate counterclockwise. At this time, the first pressure sensor mounting arm 13 will be further tilted upward to facilitate the disassembly and assembly of the first pressure sensor 14 ( Figure 7 shown).

[0053] When the two arc convex heads of the dumbbell nut 28 gradually rotate clockwise by 60°, the arc groove of the star nut 27 is no longer restricted by the two arc convex heads of the dumbbell nut 28, and the weighing lever 21 returns to its initial position under the action of gravity ( Figure 4 At this time, when the two arc convex heads of the dumbbell nut 28 gradually rotate counterclockwise by 0 to 60 degrees, the arc groove of the star nut 27 will gradually be compressed, so that the weighing lever 21 gradually returns to the horizontal position, that is, the measuring position.

[0054] The combination of the dumbbell nut 28 and the star nut 27 ensures that the weighing lever 21 can remain horizontal even if there is a certain rotation angle deviation of the core shaft gear 4, and can make the rotation of the first pressure sensor mounting arm 13 installed on the core shaft 3 smoother, thereby improving the controllability and horizontal stability of the device.

[0055] The weighing workstation further comprises: a weighing bottle conveying device for conveying the weighing bottle. The weighing bottle conveying device comprises a conveying track 130 and a conveying joint sliding in the conveying track 130; the conveying joint is formed by hingedly connecting the weighing bottle conveying joint 120.

[0056] The weighing bottle conveying device also includes a conveying section motor 132 and a conveying section dial wheel 133. A conveying section limit ring 124 higher than the plane of the weighing bottle conveying section 120 is arranged on each weighing bottle conveying section 120; the conveying section motor 132 drives the conveying section dial wheel 133 to move the conveying section limit ring 124, so that the weighing bottle conveying section 120 moves forward or backward in the horizontal direction.

[0057] The weighing workstation further includes a plurality of shielding covers, namely a core cover 100 , an electromagnetic shielding cover 108 , a buffer cover 103 and a conveying cover 105 .

[0058] like Figure 2 As shown, the weighing workstation includes a base 1, a core cover fixing platform 2, a base first baffle 8, a base second baffle 9, and an electromagnetic shielding cover fixing platform 10 fixed to the base 1 as a whole.

[0059] The plurality of shielding covers are respectively a core cover 100 , an electromagnetic shielding cover 108 , a buffer cover 103 and a transmission cover 105 .

[0060] like Figure 3 As shown, the core cover 100 can be made of a transparent polymer inert material and embedded in an area defined by the base 1, the core cover fixing platform 2, the first baffle plate 8 of the base, and the core rotating shaft 3, so as to facilitate observers and isolate air disturbances.

[0061] The electromagnetic shielding cover 108 can be produced by a graphene copper sheet composite material. The graphene surface plays an inertial protection and partial electromagnetic shielding role. The copper sheet is an excellent conductive material and can play a major electromagnetic shielding role. It is embedded and installed in the area defined by the base 1 and the electromagnetic shielding cover fixing platform 10. Six electromagnetic shielding cover coil holes 109 are opened on the top of the electromagnetic shielding cover 108 for contactless insertion of the weighing support counterweight rod 31 containing a soft iron core 32 at the bottom of the weighing support 24.

[0062] The buffer cover 103 can be made of transparent polymer inert material and embedded in the area defined by the base 1 and the second baffle plate 9 of the base, which serves to facilitate observers and further isolate air disturbances and prevent samples from accidentally dumping and contaminating the core weighing part together with the second baffle plate 9 of the base.

[0063] The conveying cover 105 can be made of transparent polymer inert material and installed on the front of the buffer cover 103 and above the electromagnetic shielding cover 108. It is used for the passage of the conveying track 130, the weighing bottle 110, and the weighing bottle conveying section 120, and can further reduce air disturbance and facilitate observation by observers.

[0064] like Figure 6-7 As shown, the core shaft gear 4 rotates clockwise, which will drive the core shaft 3 to rotate counterclockwise, causing the first pressure sensor mounting arm 13 fixed thereon to rotate counterclockwise, lifting the first pressure sensor ball head 15 and disengaging it from the weighing lever lifting hole 22, so that the other end of the weighing lever 21 falls naturally, and the bottom of the weighing bottle 110 falls back into the conveying section limit ring 124.

[0065] like Figure 8 As shown, the weighing lever support shaft 20 is the fulcrum of the weighing lever 21, the signal F1 of the first pressure sensor 14 and the effective magnetic force F generated by the electromagnetic coil 12 eff It complies with the principle of leverage.

[0066] like Fig.10 As shown, the weighing support 24 is composed of an upper part with a thicker diameter and a lower part with a thinner diameter, which can be made of a polymer inert material. The thinner diameter lower part is a weighing support counterweight rod 31, and a soft iron core 32 is wrapped in the inner center to isolate the air and increase the counterweight, so as to keep the weighing support 24 vertical. When the weighing lever 21 is in a horizontal position, the soft iron core 32 is just in Fig.12 The center position of the electromagnetic coil 12 is shown. The weighing support vent 34 serves to reduce the air damping when the weighing support 24 moves up and down.

[0067] The laser reflection platform 33 is a small raised dot on the bottom surface of the weighing tray 24, and its surface reflectivity is much higher than the rest of the weighing tray 24. Therefore, only when the weighing lever 21 is in a horizontal position and the weighing tray 24 is in a vertical position, the laser transceiver 35 can obtain a high reflection signal, ensuring that the weighing lever 21 is horizontal and the weighing tray 24 is vertical during measurement, and then ensuring that F1 and F2 are subjected to vertical forces.

[0068] like Fig. 9As shown, the upper diameter of the weighing support 24 is smaller than the weighing lever lifting ring 23, and its outer side does not contact the weighing lever lifting ring 23. It is embedded in the weighing support mounting hole 29 through the weighing support support shaft 25. Therefore, the gravity borne by the weighing support 24 is directly transmitted to the weighing support mounting hole 29, so that the force arm length of the weighing lever 24 remains accurate and stable, thereby achieving accurate measurement.

[0069] The weighing lever 24 is made of metal or alloy material with high rigidity and small expansion coefficient.

[0070] like Fig.11 As shown, the weighing bottle conveying section 120 has two conveying section ears 121, each of which has a conveying section ear hole 122. The multiple weighing bottle conveying sections 120 are connected and freely rotated in a certain range in the horizontal direction through a conveying section connecting shaft 123 embedded in the conveying section ear hole 122. The multiple weighing bottle conveying sections 120 are connected to each other and are limited to horizontal sliding in the conveying track 130.

[0071] The conveyor section limit ring 124 is higher than the plane of the weighing bottle conveyor section 120. The conveyor section motor 132 drives the conveyor section dial wheel 133 to dial the conveyor section limit ring 124, so that the weighing bottle conveyor section 120 can move forward or backward in the horizontal direction. The conveyor section dial wheel 133 is designed to move the weighing bottle conveyor section 120 by one measurement position every time it rotates 360°, so as to facilitate counting and control.

[0072] The weighing bottle 110 is composed of a weighing bottle body 114, a weighing bottle cap pad 112, and a weighing bottle cap 113. The bottom of the weighing bottle body 114 has a protruding cylindrical shape for inserting the center eye 30 of the weighing support to stabilize the weighing bottle body 114. The top outer wall thereof has a thread for screwing together with the weighing bottle cap 113. The weighing bottle cap pad 112 is embedded in the weighing bottle cap 113 to seal. The weighing bottle 110 and the weighing bottle transfer section 120 and other components can achieve proper sealing of the sample and facilitate transfer to other testing instruments, which is helpful to realize the automation of testing.

[0073] The high-precision measurement method based on the weighing workstation of the present invention comprises:

[0074] (1) Periodic correction

[0075] During measurement, the present embodiment should be placed on a horizontal and fixed table, with the weighing lever 21 in a horizontal position.

[0076] like Figure 4 and Figure 5As shown, the core shaft motor 5 drives the star nut 27 to rotate by driving the dumbbell nut 28 to make the weighing lever 21 in a horizontal position, the first pressure sensor ball head 15 of the first pressure sensor 14 is buckled into the weighing lever tilting hole 22 to obtain a signal F1, the second pressure sensor 19 obtains a vertical downward pressure signal F2, and the laser transceiver 35 obtains a center position signal ( Fig.10 ).

[0077] At this time, the weighing bottle transmission section 120 is not used, and the electromagnetic coil 12 is not energized to make the electromagnetic force zero. At this time, the first pressure sensor 14 obtains the signal F1, and the second pressure sensor 19 obtains the signal F2; then tweezers pick up 6 standard weights 131 ( Fig.11 ) are loaded on the center above the six weighing trays 24, respectively, the first pressure sensor 14 obtains a new signal F1', and the second pressure sensor 19 obtains a new signal F2'.

[0078] According to the high-precision measurement method of the present embodiment described below, one or more standard weights 131 are used to obtain the slopes k1 and k2 of the change in the signal F1 of the first pressure sensor 14, the change in the signal F2 of the second pressure sensor 19 and the change in the unit mass m.

[0079] Then remove the standard weight 131, and use the method of gradually increasing the current I in the electromagnetic coil 12 to simulate the signal F1 of the first pressure sensor 14 and the signal F2 of the second pressure sensor 19 generated by loading the standard weight, and use the "minimum residual method" or "minimum slope difference method" described below to make F1 and F2 infinitely close to the values ​​when the standard weight 131 is placed.

[0080] The current value I in the electromagnetic coil 12 at this time is recorded, and the inherent electromagnetic force conversion coefficient α of this embodiment is calculated.

[0081] (2) Power-on calibration

[0082] After the machine is turned on, the core shaft motor 5 drives the star nut 27 to rotate by driving the dumbbell nut 28 to make the weighing lever 21 in a horizontal position. The first pressure sensor ball head 15 of the first pressure sensor 14 is buckled into the weighing lever hole 22 to obtain a signal F1. The second pressure sensor 19 obtains a vertical downward pressure signal F2. The laser transceiver 35 obtains a center position signal ( Fig.10 ).

[0083] The electromagnetic coil 12 is loaded with current according to the current value I obtained by the above periodic correction to simulate the loading of the standard weight 131 .

[0084] The signal F1 of the first pressure sensor 14 and the signal F2 of the second pressure sensor 19 before and after the current loading are obtained, ΔF1 and ΔF2 are calculated, and the latest slopes k1 and k2 of the change of F1, F2 and the unit mass m are calculated according to the mass difference. The latest k1 and k2 are used to weigh the sample.

[0085] (3) Sample weighing

[0086] After the power-on calibration is completed, the instrument obtains the latest slopes k1 and k2 of the changes of F1, F2 and unit mass m.

[0087] At this time, the weighing bottle conveying section 120 is used, and the weighing support 24 lifts the weighing bottle 110 (without the cover) to make it separate from the surface of the conveying section limiting ring 124, so that all its mass is transferred to the weighing support 24, and then all the mass is transferred to the weighing support support shaft 25 of the weighing support 24.

[0088] According to the method of "3. High-precision sample weighing and peeling" below, the corrected sample mass m sample is obtained.

[0089] (4) Peeling

[0090] This function is used to eliminate the F1 and F2 signals generated on the weighing lever 21, so that the object newly loaded on the weighing support shaft 25 generates new F1 and F2 signals, and the mass of the newly added object is calculated according to the latest slopes k1 and k2.

[0091] When the weighing lever 21 is in a horizontal position, the signal F1 of the first pressure sensor 14 and the signal F2 of the second pressure sensor 19 are reset to zero, that is, the "peeling" function is realized.

[0092] (5) Automatic and continuous weighing

[0093] In this example, there are a total of 6 weighing levers 21, but the present invention may not be limited to 6 after being promoted. Taking the present invention as an example, after weighing a batch of samples in 6 weighing bottles 110, the weighing bottle conveying section 120 can slide in the conveying track 130 under the drive of the conveying section motor 132 and the conveying section dial wheel 133, remove the 6 weighing bottles 110 that have been weighed, and then bring in 6 new empty weighing bottles 110.

[0094] In this embodiment, the soft iron core 32 is a cylinder embedded in the weighing support weight rod 31. When in the measuring position, the soft iron core 32 is located at the center of the electromagnetic coil 12 ( Fig.12 shown).

[0095] To calculate the magnitude of the magnetic force on an iron core at the center of a coil of current, we need to consider the current in the coil, the number of turns in the coil, the material and size of the core, and the relative position of the core to the coil.

[0096] Assume that the number of coil turns is N, the current in the electromagnetic coil 12 is I, the coil is a standard circle, the height of the coil is L1, and the inner radius of the coil is R1; the height of the soft iron core 32 is L2, and the radius is R2; ( Fig.12 shown).

[0097] The magnetic permeability of the soft iron core is close to that of pure iron, which is about 0.016~0.024H / m, while the magnetic permeability of a vacuum is approximately 4π×10^-7H / m. Therefore, the relative magnetic permeability of the soft iron core is at least greater than 12000 and can reach up to about 19000.

[0098] When the embodiment is in the measuring position, the soft iron core 32 is located at the inner center of the electromagnetic coil 12 ( Fig.12 As shown in Figure 1, according to Ampère's circuital law, the magnetic induction intensity B at a point P at a vertical distance x from the center of the loop is:

[0099]

[0100] Where μ0 is the magnetic permeability in vacuum (4π*10 -7 H / m), R is the radius of the coil, and x is the vertical distance from point P to either end of the coil.

[0101] When the toroidal coil forms more than one closed circuit and has a certain length l, according to the Biot-Savart law, the direction of the magnetic field generated by the unit length spiral dx at a point inside the coil is as follows: Fig.13 As shown, its size is:

[0102]

[0103] Where n is the number of coil turns;

[0104] therefore:

[0105]

[0106] When the point is at the center of the coil, the magnetic induction intensity can also be expressed as (where l is the length of the coil):

[0107]

[0108] In this embodiment, the magnetic flux density distribution of the soft iron core 32 is different from that of the surrounding air. Since the magnetic permeability of the iron core is much higher than that of the air, it can be considered that 100% of the magnetic flux passes through the soft iron core 32. According to the right-hand screw rule, Fig.12 Indicated by the dashed line with arrow.

[0109] According to Lorentz's law, the effective magnetic flux density B eff It can be calculated by the following formula:

[0110] B eff =nμ0μ r B

[0111] In the formula, μ r is the relative magnetic permeability of the magnetic material; n is the number of coil turns.

[0112] The magnetic force F is proportional to the magnetic flux of the magnetic field passing through a closed surface and the current I in the energized coil generating the magnetic field. Therefore, in this embodiment, the soft iron core 32 is located at the center of the electromagnetic coil 12 and its position is fixed during measurement. Therefore, the effective magnetic force F exerted on the soft iron core 32 in the electromagnetic coil 12 is eff The calculation formula is simplified to:

[0113]

[0114] Among them, α is the inherent electromagnetic force conversion coefficient, which needs to be calibrated by the standard weight 131 and does not need to be calibrated again for a period of time.

[0115] like Figure 8 As shown, during each measurement, the weighing lever 21 is placed in a horizontal position by rotating the star nut 27 and the dumbbell nut 28, the first pressure sensor 14 obtains a signal F1, and the second pressure sensor 19 obtains a signal F2.

[0116] like Fig. 9 As shown, the weighing lever support shaft 20 is the fulcrum, L3 is the arm length of F1, and L4 is the length of F eff The length of the force arm; in this example, L4=5*L3. According to the principle of lever, the signal generated by F1 on the mass of the weight or the weighed sample can be amplified 5 times. Therefore, the slight difference in the mass of the weight or the weighed sample will also be amplified, which will improve the weighing accuracy.

[0117] Assume that the weight of the weighing lever 21 is W1; the weight of the weighing support is W2; the weight of the weighing bottle 110 (without the cover) is W3; the weight of the standard weight is W4; and the weight of the weighed sample is W5.

[0118] In order to achieve high-precision weighing, the present invention adopts two methods: periodic calibration and power-on calibration:

[0119] 1. Periodic calibration:

[0120] At this time, the weighing bottle transmission section 120 is not used, and the electromagnetic coil 12 is not energized first, so that F eff = 0, the core shaft motor 5 drives the weighing lever 21 to be in Figure 5 The horizontal position shown in FIG. 1 makes the laser transceiver 35 obtain the center position signal ( Fig.10 ); At this time, the first pressure sensor 14 obtains a signal F1, and the second pressure sensor 19 obtains a signal F2; then tweezers take 6 standard weights 131 ( Fig.11 ) are loaded on the center above the six weighing trays 24, respectively, the first pressure sensor 14 obtains a new signal F1', and the second pressure sensor 19 obtains a new signal F2'.

[0121] According to the lever principle, the following formula can be obtained:

[0122] F1×L3=W2×L4

[0123] F2=2×F1×L3+W1=2×W2×L4+W1

[0124] F1'×L3=(W2+W4)×L4

[0125] F2′=2×F1′×L3+W1=2×(W2+W4)×L4+W1

[0126] ΔF1=F1′-F1=W4×L4 / L3

[0127] ΔF2=F2′-F2=2×W4×L4

[0128] Δm=m2-m1or m-0

[0129] According to the mass of the standard weight and the gravitational acceleration g at the measurement location of this embodiment, W4 can be obtained. L3 and L4 are fixed lengths. Therefore, the slopes k1 and k2 of the change of the signal F1 of the first pressure sensor 14, the change of the signal F2 of the second pressure sensor 19 and the change of the unit mass m can be obtained by the standard weight:

[0130]

[0131] If one standard weight 131 is used, the mass is m, that is, ΔF1 and ΔF2 at two points of mass = 0 and m are obtained, and the single slope k1 and k2 values ​​can be calculated; if two standard weights 131 are used, the masses are m1 and m2 respectively, then the segmented slope k1 and k2 values ​​with slight differences in the two mass ranges of 0 to m1 and m1 to m2 can be obtained, which can further improve the accuracy of calibration. By analogy, more than two standard weights can be used.

[0132] Record the values ​​of F1' and F2' as well as k1 and k2. At this time, remove the standard weight and gradually increase the current in the electromagnetic coil 12 to generate F effSimulate the standard weights to make the first pressure sensor 14 obtain the same value as F1', and the second pressure sensor 19 obtain the same value as F2'. If there is a slight difference, two methods can be used for precise adjustment: (1) "minimum residual method", that is, to minimize ΔF = 2*ΔF1' + ΔF2', (2) "minimum slope difference method", that is, to minimize Δk = 2*Δk 1' + Δk2'. At this time, record the value I of the current in the electromagnetic coil 12, and the following formula is obtained:

[0133]

[0134] ΔW4=(m2-m1)g

[0135] ΔI = Current I2 when the mass m2 weight is placed and balanced - Current I1 when the mass m1 weight is placed and balanced

[0136] Using two standard weights m1 and m2, ΔW4 and ΔI are obtained, and α can be calculated. After the instrument is stored, it is fixed before the next periodic calibration. α is the inherent electromagnetic force conversion coefficient. It is generally fixed for the same instrument and is used to evaluate whether the instrument is stable. When the α value fluctuates greatly, it prompts to fully check the performance and status of the instrument.

[0137] 2. Power-on calibration:

[0138] The weighing lever 21 is a movable part, and the length of the lever arm is closely related to the weighing accuracy. Under different room temperature and humidity conditions, there may be very slight deformations that affect the accuracy. Therefore, each time the instrument is turned on and used for measurement functions, a power-on calibration can be performed. At this time, the weighing bottle conveying section 120 is not used.

[0139] After the machine is turned on, the weighing lever 21 is in a horizontal position by rotating the star nut 27 and the dumbbell nut 28, and the laser transceiver 35 obtains a center position signal ( Fig.10 ). The first pressure sensor 14 obtains the signal F1, and the second pressure sensor 19 obtains the signal F2. According to the current value I obtained by the above periodic correction, the electromagnetic coil 12 is loaded with current to simulate the loading of the standard weight 131 (mass m). Then according to the following formula:

[0140] F1×L3=W2×L4

[0141] F2=2×F1×L3+W1=2×W2×L4+W1

[0142] F1'×L3=(W2+W4)×L4

[0143] F2′=2×F1′×L3+W1=2×(W2+W4)×L4+W1

[0144] ΔF1=F1′-F1=W4×L4 / L3

[0145] ΔF2=F2′-F2=2×W4×L4

[0146] Obtain the signal F1 of the first pressure sensor 14 before current loading and the signal F1' of the first pressure sensor 14 after current loading, and calculate ΔF1. Obtain the signal F2 of the second pressure sensor 19 before current loading and the signal F2' of the second pressure sensor 19 after current loading, and calculate ΔF2. Assume that m=0 before current loading, and simulate the equilibrium state of loading a standard weight (mass m) after current I loading. W4=m.

[0147] According to: k1 = ΔF1 / Δm k2 = ΔF2 / Δm

[0148] Calculate the latest slopes k1 and k2 of the change of F1, F2 with unit mass m. Use the latest k1 and k2 to weigh the sample in the next step.

[0149] 3. High-precision sample weighing and peeling

[0150] After the power-on calibration is completed, the instrument obtains the signal F1 of the first pressure sensor 14, the signal F2 of the second pressure sensor 19 and the latest slopes k1 and k2 of the change of the unit mass m.

[0151] At this time, the weighing bottle conveying section 120 is used, and the weighing support 24 lifts the weighing bottle 110 (without the cover) to make it separate from the surface of the conveying section limiting ring 124, so that all its mass is transferred to the weighing support 24, and then all the mass is transferred to the weighing support support shaft 25 of the weighing support 24.

[0152] At this time, the signal F1 of the first pressure sensor 14 and the signal F2 of the second pressure sensor 19 are reset to zero, that is, the "peeling" function is realized.

[0153] The following formulas are used before and after the weighing bottle 110 contains a sample:

[0154] F1×L3=(W2+W3)×L4

[0155] F2=2×F1×L3+W1=2×(W2+W3)×L4+W1

[0156] F1'×L3=(W2+W3+W5a)×L4

[0157] F2′=2×F1′×L3+W1=2×(W2+W3+W5b)×L4+W1

[0158] ΔF1=F1′-F1=W5a×L4 / L3

[0159] ΔF2=F2′-F2=2×W5b×L4

[0160] Among them, the mass of the sample calculated by ΔF1 is assumed to be W5a, and the mass of the sample calculated by ΔF2 is assumed to be W5b. At this time, the latest slopes k1 and k2 are obtained according to the power-on calibration;

[0161] According to: k1 = ΔF1 / Δm k2 = ΔF2 / Δm

[0162] The Δm calculated from ΔF1 and ΔF2 can be obtained respectively. Theoretically, the two results should be consistent, but in reality there will be a slight difference. At this time, the "residual uniformity method" is used for correction, and the formula is as follows:

[0163]

[0164] Among them, the W5 correction value is the corrected sample mass.

[0165] In this way, the systematic error and the accidental error are reduced by two pressure sensors, and a high-precision correction of the mass of the sample is achieved.

Claims

1. A weighing workstation, characterized in that: include: A weighing bottle weighing device comprises a weighing lever (21), a weighing lever bracket (18) and a weighing lever horizontal adjustment mechanism; the weighing lever (21) is arranged on the weighing lever bracket (18); the weighing lever horizontal adjustment mechanism is arranged at the proximal end of the weighing lever (21) and is used to adjust the horizontal state of the weighing lever; a first pressure sensor (14) is arranged at the contact position between the weighing lever horizontal adjustment mechanism and the proximal end of the weighing lever (21); a second pressure sensor ( 19); a weighing support (24) hinged to the weighing lever (21) is provided at the far end of the weighing lever (21); a weighing support center eye (30) for embedding a weighing bottle is provided at the upper end of the weighing support (24); a soft iron core (32) is provided at the lower end of the weighing support (24); a coil mounting column (11) is provided below the weighing support (24), and an electromagnetic coil (12) is provided in the coil mounting column (11); when the weighing support (24) moves up and down, the soft iron core (32) is inserted into the electromagnetic coil (12).

2. The weighing workstation according to claim 1, characterized in that: The weighing rod horizontal adjustment mechanism comprises a core rotating shaft (3), a core rotating shaft motor (5) and a first pressure sensor mounting arm (13); the core rotating shaft motor (5) drives the core rotating shaft (3) to rotate, the first pressure sensor mounting arm (13) is arranged on the core rotating shaft (3), the first pressure sensor (14) is arranged on the first pressure sensor mounting arm (13), and a first pressure sensor ball head (15) is arranged on the first pressure sensor (14); the first pressure sensor ball head (15) contacts the proximal end of the weighing lever (21).

3. The weighing workstation according to claim 2, characterized in that: The weighing rod horizontal adjustment mechanism also includes a core rotating shaft gear (4), a core rotating shaft pinion gear (7), a star nut (27) and a dumbbell nut (28); the core rotating shaft gear (4) is meshed with the core rotating shaft pinion gear (7); the core rotating shaft pinion gear (7) is connected to the core rotating shaft motor (5); the dumbbell nut (28) is arranged on the core rotating shaft gear (4); the star nut (27) is meshed with the dumbbell nut (2) 8; and the star nut (27) is arranged on the core rotating shaft (3).

4. The weighing workstation according to claim 3, characterized in that: The outer side surface of the star nut (27) is formed with four arc grooves; the dumbbell nut (28) has two centrally symmetrical arc convex heads; the arc convex heads of the dumbbell nut (28) are adapted to the arc grooves of the star nut (27), that is, because of their shapes, they are effectively restrained from rotating each other, the dumbbell nut (28) is active, and the star nut (27) is driven; When the two arc convex heads of the dumbbell nut (28) are arranged vertically, the angle is 0°, and the weighing lever (21) is in a horizontal position, i.e., a measuring position; When the two arc convex heads of the dumbbell nut (28) gradually rotate counterclockwise by 0 to 30° or clockwise by 0 to 60°, the arc groove of the star nut (27) is gradually no longer restricted by the two arc convex heads of the dumbbell nut (28), and the weighing lever (21) gradually returns to its initial position under the action of gravity; When the two arc convex heads of the dumbbell nut (28) rotate counterclockwise by 30° and then gradually rotate clockwise by 0 to 30°, the first pressure sensor mounting arm (13) will gradually tilt upwards to facilitate the disassembly and assembly of the first pressure sensor (14); When the two arc convex heads of the dumbbell nut (28) rotate 60° clockwise and then gradually rotate 0-60° counterclockwise, the weighing lever (21) will gradually return to the horizontal position, i.e., the measuring position; The dumbbell nut (28) and the star nut (27) are combined so that even if there is a certain rotation angle deviation of the core rotating shaft gear (4), the weighing lever (21) can still be kept horizontal, and the first pressure sensor mounting arm (13) mounted on the core rotating shaft (3) can be rotated more smoothly, thereby improving the controllability and horizontal stability of the device.

5. The weighing workstation according to any one of claims 1 to 4, characterized in that: Also includes: The weighing bottle conveying device is used for conveying the weighing bottles.

6. The weighing workstation according to claim 5, characterized in that: The weighing bottle conveying device comprises a conveying track (130) and a conveying joint sliding in the conveying track (130); the conveying joint is formed by hingedly connecting the weighing bottle conveying joint (120).

7. The weighing workstation according to claim 6, characterized in that: The weighing bottle conveying device further comprises a conveying section motor (132) and a conveying section dial wheel (133); a conveying section limiting ring (124) higher than the plane of the weighing bottle conveying section (120) is arranged on each weighing bottle conveying section (120); the conveying section motor (132) drives the conveying section dial wheel (133) to dial the conveying section limiting ring (124), so that the weighing bottle conveying section (120) moves forward or backward in a horizontal direction.

8. The weighing workstation according to claim 7, characterized in that: Also includes: The plurality of shielding covers are respectively a core cover (100), an electromagnetic shielding cover (108), a buffer cover (103) and a transmission cover (105).

9. The measuring method based on the weighing workstation according to any one of claims 1 to 8, characterized in that: include: Calibrate the weighing workstation, including periodic calibration and power-on calibration; the periodic calibration is to use two standard weights of different masses to calculate the inherent electromagnetic force conversion coefficient α, which is stored in the instrument and fixed before the next periodic calibration; the power-on calibration is to calculate the latest slopes k1 and k2 of the signal F1 of the first pressure sensor (14), the signal F2 of the second pressure sensor (19) and the change of the unit mass m; Weigh the sample. Assume that the mass of the sample calculated by ΔF1 is W5a, and the mass of the sample calculated by ΔF2 is W5b. Then: Among them, the W5 correction value is the corrected sample mass.

10. The measuring method according to claim 9, characterized in that: ΔF1 and ΔF2 are: ΔF1=W4×L4 / L3 ΔF2=2×W4×L4 Wherein, W4 is the weight of the standard weight; L3 is the distance from the middle hinge point of the weighing lever (21) to the near end; and L4 is the distance from the middle hinge point of the weighing lever to the far end.

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