Double-metering belt scale
Technical Field
The invention relates to the technical field of material weighing and metering, in particular to a double-metering belt scale.
Background
The belt weigher is widely used in railway stations, ports, airports and other production enterprises, such as coal mines, thermal power generation, steel, cement building materials and the like. The traditional belt weigher is limited by a metering principle and a structure, is suitable for weighing loose materials with uniform weight, and when fuel such as coal is weighed, large, medium and small coal blocks are mixed with crushed coal, so that the metering precision is influenced; after the belt weighers run for a period of time, due to the action of various factors, metering errors are increased, and the belt weighers need to be calibrated.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a double-metering belt scale.
In order to achieve the purpose, the invention adopts the technical scheme that:
a double-metering belt scale is placed on a bearing platform and comprises a driving roller, a cross beam, a belt, a driven roller, a rolling support, a hinged support, a driving device, a driving roller front support, a driven roller support and a belt scale display instrument, wherein the cross beam is fixedly connected with the driving roller front support and the driven roller support and supports the driving roller and the driven roller, the belt is arranged between the driving roller and the driven roller, a conveyed object is moved through the belt, the rolling support is arranged at the bottom of the driven roller support, the driving device is arranged on the driving roller front support opposite to the driven roller support, the hinged support is arranged at the bottom of the driving roller front support, the driving roller is driven by the driving device to move, the driven roller follows, the belt scale is arranged in a front-back symmetrical mode along the central axis of the belt scale except the driving device, the front-back symmetry is required to ensure that the gravity center is in a geometric center, the middle part of the beam is provided with a measuring section and supported by an auxiliary roller wheel, a driven roller bracket is provided with a fixed side roller and a rolling wheel, a force sensor is arranged between the rolling support and a bearing platform foundation and below the rolling wheel, a first processing module in a belt scale display instrument is connected with the force sensor and a photoelectric tachometer and carries out conveyed material metering through data transmitted by the force sensor and the photoelectric tachometer, and the belt scale display instrument displays the conveying quality in unit time, the accumulated conveying quality and the accumulated time, which is a first metering mode.
Further, the calculation steps of the unit time conveying quality, the accumulated conveying quality and the accumulated time are as follows:
the belt weigher is G kilograms in self weight, X kilograms in conveyed object weight, W kilograms in driving device weight, R kilograms in average reading of a force sensor, the known belt weigher is used for conveying L meters in distance, a moment equation is established by taking a rotating shaft of a hinged support as a base point, the belt weigher is 0.5L meters in self-gravity arm, the conveyed object is considered to be uniformly distributed, then the moment arm is 0.5L meters, the driving device moment arm is C meters, and the conversion equation can be obtained:
x ═ 2R-G-2WC/l (kg) formula one
The diameter of a driving roller of the belt scale is D meters, the reading of the photoelectric tachometer is n revolutions per second, and the linear speed of the belt scale is as follows:
v ═ pi Dn (m/s) formula two
The time taken for the transported object to pass through the distance L is as follows:
l/(pi Dn)(s) formula three
The conveying quality of the belt weigher in unit time is as follows:
G1=X/τ=3.6πDn(2RL-GL-2WC)/L2(t/h) formula IV
The accumulated conveying mass is as follows:
the accumulated time is:
Δ τ 2 τ 1 equation six
Further, still include the auxiliary stand, the crossbeam middle part is equipped with the measurement section, two supplementary running rollers and four supplementary side rollers are add to the belt below and its pivot is all fixed on the auxiliary stand, the auxiliary stand is connected with the crossbeam through short column, arrange the foil gage that is used for monitoring its deformation and the temperature sensor who is used for monitoring the temperature on the short column, second processing module in the belt weigher display instrument links to each other with foil gage and temperature sensor and carries out the transported substance measurement through the data of foil gage and temperature sensor conveying, show unit interval transport quality, accumulative transport quality and accumulative total time through the belt weigher display instrument.
The belt weigher is characterized by further comprising a driving roller, a cross beam, a belt, a driven roller, a driving device, an auxiliary support, a driving roller front support, a driven roller support and a belt weigher display instrument, wherein the cross beam is fixedly connected with the driving roller front support and the driven roller support and supports the driving roller and the driven roller, the belt is arranged between the driving roller and the driven roller, a conveyed object is moved through the belt, the driving device is arranged on the driving roller front support opposite to the driven roller support, the driving roller is driven by the driving device to move, the driven roller follows the driving device, the belt weigher is arranged in a front-back symmetrical mode along the central axis of the belt weigher except the driving device, the gravity center of the belt weigher is ensured to be at the geometric center, two auxiliary rollers and four auxiliary side rollers are additionally arranged below the belt, rotating shafts of the belt weigher are all fixed on the auxiliary support, the second processing module in the belt weigher display instrument is connected with the strain gauge and the temperature sensor and carries out conveyed object metering through data transmitted by the strain gauge and the temperature sensor, and the belt weigher display instrument displays the conveying quality, the accumulated conveying quality and the accumulated time in unit time, which is a second metering mode.
Furthermore, the auxiliary support is provided with four short columns which are connected with the cross beam, two strain gauges and a temperature sensor are uniformly arranged on each short column, and the acting force on the short columns is monitored through the strain gauges.
Further, the calculating step of the second processing module is:
the load on the belt is transmitted to four short columns of the auxiliary support through the auxiliary roller wheel and the auxiliary side roller, the four short columns are stressed and deformed, the deformation is caused by pulling at the inner side and pressing at the outer side, the deformation is respectively monitored by the strain gauges on the short columns, the short columns expand with heat and contract with cold due to the temperature change, the temperature of the short columns is detected by the temperature sensors on the short columns, the signals of the strain gauges and the temperature sensors are received by the second processing module in the display instrument of the belt scale, the temperature automatic compensation is carried out, and the gravity on the four short columns of the measurement section is1、X2、X3、X4Measuring the mass X of the conveyed material in the section0Comprises the following steps:
x0 ═ X1+ X2+ X3+ X4 formula hepta
Because the length of the measuring section is 0.1L, the total mass X of the conveyed materials of the belt weigher is as follows:
X10X 0 formula eight
Furthermore, the belt scale display instrument is provided with two processing modules, namely a first processing module and a second processing module, which both have an integral calculation function, wherein the first processing module is specially used for processing signals transmitted by the force sensor and the photoelectric tachometer, and displaying accumulated time (hour), accumulated conveying mass (ton) and conveying mass (ton/hour) in unit time, which is a first metering mode; the second processing module is specially used for processing signals transmitted by the strain gauge and the temperature sensor, and display information is consistent with that of the first module and is in a second metering mode; under the condition of uniform speed, the measuring section is from right to left and is consistent with the time from the rear end to the front end of the whole belt, and the mass of the conveyed object of the whole belt is 10 times of that of the measuring section, so that the calculation results of the two metering modes are completely the same when the errors are not considered for the conveying mass per unit time, the accumulated conveying mass and the accumulated time, and the two methods can be used simultaneously or independently; the first one measures the force directly, only the rolling support, the second one calculates the force by measuring the deformation, the process is complex, the second one is more accurate in a longer time, especially the mass is delivered in a unit time, but the time is too long, the accumulated delivery mass error will be increased, because the first one measures 10 times corresponding to the measurement section.
Furthermore, the belt weigher is provided with two force sensors in a front-back symmetrical mode, the rolling supports mounted on the driven roller supports are provided with two rolling wheels in a front-back symmetrical mode, the rolling wheels mounted on the driven roller supports are provided with two rolling wheels in a front-back symmetrical mode, one force sensor is mounted between each rolling support and the bearing platform foundation and below each rolling wheel, and errors can be effectively reduced under the condition that the belt loading capacity is unbalanced left and right.
Further, two supplementary running rollers are supported by four short columns, and the short column utilizes the first spout that sets up on it to pass through hexagonal fastening nut to be fixed on the crossbeam, and the spout that sets up on the crossbeam passes through hexagonal fastening nut fixedly connected with anchorage bar one end, and the anchorage bar other end passes through round pin post connecting short column, and is rotatable each other, and the anchorage bar can follow the spout and slide.
Furthermore, the measurement of the conveyed objects is carried out by adopting a force sensor and a photoelectric tachometer, which is a first measurement mode, and the measurement result is accurate; the belt weigher is characterized in that the length range of 0.1L in the middle of the belt weigher is a measuring section, two auxiliary rollers and four auxiliary side rollers are additionally arranged below the belt, an auxiliary support is provided with four short columns which are connected with a cross beam, two strain gauges and a temperature sensor are uniformly arranged on each short column, the quality of conveyed objects is measured by using signals of the strain gauges and the temperature sensor, the second measuring mode is adopted, the strain gauges have high precision, the temperature sensor is used for temperature compensation, longitudinal and transverse quality changes of the measuring section have no influence, and the measuring precision is high; the first metering mode can be calibrated frequently by reading in the second metering mode, and the second metering mode can be calibrated accurately by using no-load and on-load without frequent calibration.
Furthermore, the double-metering belt scale can be used for a horizontal belt scale and an inclined belt scale, and the short column is only required to be vertical.
Compared with the prior art, the invention has the beneficial effects that:
1. the belt weigher has two metering modes, and has the advantages of simple structure, high reliability and high overall precision.
2. The double-metering mode is suitable for both horizontal belt weighers and inclined belt weighers, and does not influence the precision.
3. The second metering mode does not need to be calibrated frequently, and the first metering mode can be calibrated quickly.
4. The belt weigher can weigh uneven materials such as raw coal and the like, and can ensure certain accuracy.
Drawings
FIG. 1 is a schematic diagram of the overall structure of a dual-metering belt scale of the present invention;
FIG. 2 is a side schematic view of a driven roller bracket according to the present invention;
FIG. 3 is a schematic diagram of a strain gage placement test of the present invention;
FIG. 4 is an enlarged schematic view of a strain gage measurement section of the present invention;
wherein, 1-driving roll; 2-a cross beam; 3, a belt; 4-auxiliary roller wheels; 5-a driven roller; 6-rolling support; 7-a force sensor; 8-hinged support; 9-a cushion cap foundation; 10-a drive device; 11-a conveyance; 12-fixed side rolls; 13-a rolling wheel; 14-auxiliary side rolls; 15-a rotating shaft; 16-a strain gauge; 17-a temperature sensor; 18-an auxiliary support; 19-short column; 20-hexagonal fastening nuts; 21-a pin; 22-a chute; 23-fastening the rod.
Detailed Description
The present invention will be further described with reference to the following examples.
As shown in fig. 1-4, a double-metering belt scale is arranged on a bearing platform foundation 9, and comprises a driving roller 1, a cross beam 2, a belt 3, an auxiliary roller wheel 4, a driven roller 5, a rolling support 6, a force sensor 7, a hinged support 8, a driving device 10, a conveyed object 11, a fixed side roller 12, a rolling wheel 13, an auxiliary side roller 14, a rotating shaft 15, a strain gauge 16, a temperature sensor 17, an auxiliary support 18, a short column 19, a hexagonal fastening nut 20, a pin column 21, a sliding groove 22, a fastening rod 23, a driving roller front support, a driven roller support and a belt scale display instrument, wherein the cross beam 2 is fixedly connected with the driving roller front support and the driven roller support, the driving roller 1 and the driven roller 5 are supported by the cross beam 2, the driving roller front support and the driven roller support, the belt 3 is arranged between the driving roller 1 and the driven roller 5, the conveyed object 11 is moved by the belt 3, the belt scale is arranged symmetrically front and back, the gravity center of the belt weigher is ensured to be at a geometric center, rolling supports 6 are installed at the bottom of a driven roller support, two rolling supports 6 are symmetrically arranged in the front and back direction, a driving device 10 is installed on a front drive roller support opposite to the driven roller support, a hinged support 8 is installed at the bottom of the front drive roller support, two hinged supports 8 are symmetrically arranged in the front and back direction, a driving roller 1 is driven by the driving device 10 to move, a driven roller 5 follows, a belt 3 follows and moves to move a conveyed object 11, a belt weigher display instrument is installed on a control console, a photoelectric tachometer is arranged on the driving roller 1, a measuring section is arranged in the middle of a cross beam 2 and is provided with an auxiliary roller 4 and the like, a fixed side roller 12 and a rolling wheel 13 are installed on the driven roller support, two rolling wheels 13 are symmetrically arranged in the front and back direction, a force sensor 7 is installed between, the number of the force sensors 7 is two, a first processing module in a belt scale display instrument is connected with the force sensors 7 and the photoelectric tachometer, conveyed objects 11 are measured through data transmitted by the force sensors 7 and the photoelectric tachometer, and the belt scale display instrument displays the conveying quality per unit time, the accumulated conveying quality and the accumulated time.
The self weight G kilogram of the double-metering belt weigher, 11 weight X kilogram of conveyed object, 10 self weight W kilogram of the drive device, average reading R kilogram of two force sensors 7, known belt weigher conveying distance L meter, use 8 axes of rotation of hinged support as the base point to set up the moment equation, the belt weigher is from 0.5L meter of the gravity arm, consider that the conveyed object 11 is evenly distributed, then 0.5L meter of its arm of force, 10C meters of the arm of force of the drive device, the transformation equation can be obtained:
x ═ 2R-G-2WC/l (kg) formula one
Belt weigher driving roll 1 diameter D meter is equipped with the photoelectricity tachometer, and its reading n is changeed/second, then the belt linear velocity is:
v ═ pi Dn (m/s) formula two
The time taken for the transported object 11 to pass through the distance L is:
r L/v L/(pi Dn)(s) formula III
The conveying quality of the belt weigher in unit time is as follows:
G1=X/τ=3.6πDn(2RL-GL-2WC)/L2(t/h) formula IV
The accumulated conveying mass is as follows:
the accumulated time is:
Δ τ 2 τ 1 equation six
The belt weigher adopts a groove-shaped belt, can load more conveyed objects 11, a force sensor 7 is arranged below each rolling wheel 13, and the readings of the two force sensors 7 are respectively counted as R1、R2The average reading of the two force sensors 7 is R, R ═ 0.5 (R)1+R2) And under the condition that the loading capacity of the belt 3 is unbalanced left and right, the error can be effectively reduced.
The belt scale display instrument is provided with two processing modules, namely a first processing module and a second processing module, which are both provided with an integral calculation function, wherein the first processing module is specially used for processing signals transmitted by the force sensor 7 and the photoelectric tachometer and displaying accumulated time (hour), accumulated conveying mass (ton) and conveying mass (ton/hour) in unit time; the second processing module is specially used for processing signals transmitted by the strain gauge 16 and the temperature sensor 17, and display information is consistent with that of the first processing module.
The method adopts the force sensor 7 and the photoelectric tachometer to measure the conveyed objects 11, is a first measuring mode, and has the advantages that the precision of the force sensor 7 and the photoelectric tachometer is high, so that the conveyed objects 11 in the length direction of the belt scale are possibly not uniform, the overall measuring result is accurate and reliable, and the accuracy is further improved if the conveyed objects are calibrated and reused in advance.
The second measuring method of the belt weigher measures the mass of the conveyed material 11 by using signals of the strain gauge 16 and the temperature sensor 17. The length range of 0.1L in the middle of the belt scale is a measuring section, two auxiliary rollers 4 and four auxiliary side rollers 14 are additionally arranged below the belt, and rotating shafts 15 of the auxiliary rollers are fixed on an auxiliary support 18; the auxiliary support 18 is provided with four short columns 19 connected with the beam 2, and two strain gauges 16 and a temperature sensor 17 are arranged on each short column 19.
The measurement principle is as follows: the load on the belt 3 is transmitted to four short columns 19 of the belt auxiliary support 18 through the auxiliary roller 4 and the auxiliary side roller 14, the four short columns 19 are stressed and deformed, the deformation is realized by pulling at the inner side and pressing at the outer side, the deformation is respectively monitored by corresponding strain gauges 16 on the four short columns 19, the short columns expand with heat and contract with cold due to the temperature change, so that a temperature sensor 17 is arranged to detect the temperature of the short columns, the signals of the strain gauges 16 are transmitted to a belt scale display instrument for processing, the temperature is automatically compensated, and the gravity X borne by the four short columns of the measuring section is respectively obtained1、X2、X3、X4Then the mass of the measurement section transported material 11 is:
X0=X1+X2+X3+X4formula seven
Because the length of the measuring section is 0.1L, the total mass of the conveyed materials 11 of the belt weigher is as follows:
X=10X0equation eight
The time taken for the transported object 11 to pass the distance L is constant, and is still τ, and other calculations are the same as in the first metering method. The strain gauge 16 has high precision, the temperature sensor 17 is used for temperature compensation, and the longitudinal and transverse mass changes of the measuring section are not influenced, so the second measuring mode has high measuring precision.
And a second metering mode is calibrated: inputting corresponding temperature and calibrating a load zero point when the belt weigher is unloaded in winter and summer; inputting corresponding temperature and calibrating load reading when the belt weigher is in actual load in winter and summer; the calibration period is greatly prolonged. Calibration in a first metering mode: the calibration is carried out by reading in the second metering mode, which can be carried out quickly and in short period and is convenient.
The support structure of the measuring section is as follows: the two auxiliary rollers 4 are supported by four short columns 19, the short columns 19 are fixed on the cross beam 2 through adaptive hexagonal fastening nuts 20 by utilizing first sliding grooves formed in the short columns 19, one end of a fastening rod 23 is fixedly connected with sliding grooves 22 formed in the cross beam 2 through matched hexagonal fastening nuts 20, the other end of the fastening rod 23 is connected with the short columns 19 through pins 21 and can rotate mutually, and the fastening rod 23 can slide along the sliding grooves 22.
The invention can be used for a horizontal belt scale and an inclined belt scale; as mentioned above, for a horizontal belt scale, if the belt scale is inclined, the first measurement mode does not need to be changed, but the second measurement mode is a little different, i.e. in order to ensure the correct signal output of the strain gauge 16, the short column 19 needs to be adjusted to keep vertical, and the adjustment before use is as follows: by utilizing the sliding groove 22, the short column 19 is kept vertical, the auxiliary roller 4 is tangent to the belt 3, the fastening rod 23 moves along with the short column 19 through the pin column 21, and finally the hexagonal fastening nut 20 is screwed, so that the cross beam 2, the short column 19 and the fastening rod 23 form a stable triangular stress component.
The above embodiments do not limit the present invention in any way, and all technical solutions obtained by means of equivalent substitution or equivalent transformation fall within the scope of the present invention.