JP4648162B2 - Weight sorter - Google Patents

Description

  The present invention relates to a weight sorting apparatus that measures a weight while transporting an object to be weighed, and blows off in a sorting direction by air injection from an air jet means while transporting at a later stage when the object to be weighed is an NG product. In particular, the present invention provides a weight sorting apparatus configured so that a change in atmospheric pressure due to air injection from an air jet means does not adversely affect weight measurement.

  The following Patent Document 1 excludes one of two articles sent on a conveyer at an interval smaller than the interval in the conveyance direction necessary for weight measurement, using an air jet nozzle, Discloses an apparatus that prevents the article from appearing together.

Patent Document 2 listed below is a weight inspection device that measures the weight while being transported by a weighing conveyor and distributes the NG product that is transported in the next-stage sorting conveyor by the air jetted from the air nozzle. In order to eliminate the measurement error, an auxiliary member is provided above the weighing conveyor, and the influence of the air flow caused by the air nozzle is eliminated by using a force component due to the pressure difference generated in the vertical direction.
Utility Model Registration No. 2536179 JP 2004-361156 A

  According to Patent Document 1 described above, when an air jet is ejected from an air jet nozzle to remove an article, the air pressure changes in the vicinity of the weighing device. There was a problem that an error in the weight value was inevitable.

  In the invention disclosed in Patent Document 2, in order to prevent such a measurement error in the weighing conveyor due to air injection, an auxiliary member is provided above the weighing conveyor to generate an upward force and a downward force to cancel each other. However, according to this method, there is a problem in that the balance of each force changes depending on the size of the article passing through the line, and the influence cannot be reduced with high accuracy. In addition, there is a problem that the accuracy of effect reduction is not good for the time-consuming work, for example, it is necessary to finely adjust the auxiliary member every time the article changes.

  The present invention has been made to solve the problems as described above, and measures the weight while transporting the object to be weighed. If the weighed object to be weighed is an NG product, it is transported at the subsequent stage. However, an object of the present invention is to reduce the influence of air jets for eliminating NG products on weight measurement with high accuracy with a simple configuration in a weight sorting apparatus that blows off in the sorting direction by air jetting of air jet means.

The weight sorting apparatus according to claim 1 is:
A first conveying means 4 for conveying an item to be weighed; a detecting means 7 provided in the vicinity of the first conveying means 4 for detecting the entry of the item to be weighed and outputting a detection signal; and the first conveying means 4 A weight measuring unit 2 having weight measuring means 8 for measuring the weight of the item to be weighed conveyed at a predetermined timing based on the detection signal;
According to the result of measurement by the weight measuring unit 2, the second transport unit 5 provided adjacent to the first transport unit 4 and the weighed product transported by the second transport unit 5. A sorting section 3 having air jet means 6 for sending out in a direction different from the transport direction of the second transport means 5 by air injection to be performed;
In a weight sorter equipped with
Measurement timing calculation means 12 for calculating a measurement timing based on a preset conveyance speed and conveyance length of the first conveyance means 4;
An influence time range in which the air jet unit 6 affects the weight measurement by the weight measuring unit 8 is calculated based on an arbitrary initial position of the air jet unit set in advance and a propagation velocity of the air injection determined in advance. Influence time range calculating means 13 for
Setting position calculation means 14 for calculating and outputting an installation position range of the air jet means 6 from the measurement timing and the influence time range so that the measurement timing and the influence time range do not overlap each other;
It is characterized by having.

The weight sorting apparatus according to claim 2 is:
A first conveying means 4 for conveying an item to be weighed; a detecting means 7 provided in the vicinity of the first conveying means 4 for detecting the entry of the item to be weighed and outputting a detection signal; and the first conveying means 4 A weight measuring unit 2 having weight measuring means 8 for measuring the weight of the item to be weighed conveyed at a predetermined timing based on the detection signal;
According to the result of measurement by the weight measuring unit 2, the second transport unit 5 provided adjacent to the first transport unit 4 and the weighed product transported by the second transport unit 5. A sorting section 3 having air jet means 6 for sending out in a direction different from the transport direction of the second transport means 5 by air injection to be performed;
In a weight sorter equipped with
An influence time range in which the air jet unit 6 affects the weight measurement by the weight measuring unit 2 based on an arbitrary initial position of the air jet unit 6 set in advance and a propagation velocity of air injection determined in advance. An influence time range calculating means 22 for calculating;
Measurement timing calculation means 24 for calculating and outputting a measurement timing that does not overlap with the influence time range at the installation position of the air jet means 6 set arbitrarily;
It is characterized by having.

The weight sorting apparatus according to claim 3 is:
A first conveying means 4 for conveying an item to be weighed; a detecting means 7 provided in the vicinity of the first conveying means 4 for detecting the entry of the item to be weighed and outputting a detection signal; and the first conveying means 4 A weight measuring unit 2 having weight measuring means 8 for measuring the weight of the item to be weighed conveyed at a predetermined timing based on the detection signal;
According to the result of measurement by the weight measuring unit 2, the second transport unit 5 provided adjacent to the first transport unit 4 and the weighed product transported by the second transport unit 5. A sorting section 3 having air jet means 6 for sending out in a direction different from the transport direction of the second transport means 5 by air injection to be performed;
In a weight sorter equipped with
Measurement timing calculation means 33 for calculating a measurement timing based on a preset conveyance speed and conveyance length of the first conveyance means 4;
At the measurement timing, the air jet start timing and the air injection end of the air jet means 6 are prevented so that the weight measurement by the weight measuring unit 2 is not affected by the air jet means 6 set at an arbitrary installation position. Injection timing calculating means 34 for calculating and outputting at least one of the timings;
It is characterized by having.

The weight sorting apparatus according to claim 4 is the weight sorting apparatus according to claim 1,
A display means for displaying the output installation position range of the air jet means 6 is provided.

The weight sorting apparatus according to claim 5 is the weight sorting apparatus according to claim 1,
A position setting means 15 for setting the position of the air jet means 6 based on the output installation position range of the air jet means 6 is provided.

  According to the weight selection apparatus described in claim 1, the start or stop of air injection by the air jet means influences the measurement timing of the weight by the weight measurement unit and the measurement of the weight of the object to be weighed by the weight measurement unit. The position of the air jet means with respect to the weight measuring unit is determined so that it does not overlap with the influence time range that affects the pressure, and the position of the air jet means can be set appropriately based on this information. The disadvantage that the accuracy of the weight measurement is reduced is avoided.

  According to the weight sorting apparatus described in claim 2, the influence time range in which the air jet means influences the measurement of the weight by the weight measuring means, and an arbitrarily set installation position of the air jet means. Since the measurement timing which does not overlap with the influence time range can be calculated, and the weight measurement can be performed by this weight measurement unit, the inconvenience that the accuracy of the weight measurement is lowered due to the atmospheric pressure change due to the injection of the air jet is avoided. .

  According to the weight selection apparatus of the third aspect, the air jet means set at an arbitrary installation position does not affect the weight measurement by the weight measurement means at the weight measurement timing by the weight measurement unit. In addition, since the start timing or the end timing of the air jet of the air jet means can be set appropriately, the inconvenience that the accuracy of the weight measurement is reduced due to the change in the atmospheric pressure due to the jet of the air jet is avoided.

  According to the weight sorting apparatus described in claim 4, since the installation position range of the air jet means output by the weight sorting apparatus according to claim 1 can be displayed on the display means, the user of this apparatus can display this display. The position of the air jet means can be set appropriately by visual recognition.

  According to a fifth aspect of the present invention, the weight selecting apparatus controls the position setting means for moving the air jet based on the information indicating the installation position range of the air jet means output from the weight selecting apparatus according to the first aspect. The air jet means can be automatically set to an appropriate position.

Next, the best mode for carrying out the present invention will be described.
FIG. 1 is a schematic diagram showing an example of a mechanical configuration of an embodiment (hereinafter referred to as this example) of a weight sorting apparatus according to the present invention, FIG. 2 is a flowchart showing a weight measurement procedure in the embodiment, and FIG. FIG. 4 is a timing diagram of measurement and air jet injection showing the problem of weight measurement in the sorting device, and FIG. 4 shows the influence of the injection of the air jet means on the weighing accuracy at each interval between the air jet means and the weight measurement unit in the embodiment. FIG. 5 is a graph showing the relationship between the interval between the air jet unit and the weight measuring unit and the elapsed time from the start of injection of the air jet unit in the embodiment. FIG. 6 is a diagram showing an influence time range in which the injection of the air jet means affects the weighing accuracy. FIG. 6 shows the interval between the air jet means and the weight measuring unit, and the air jet means in the embodiment. FIG. 7 is a graph showing the relationship with the elapsed time from the start of shooting, showing the measurement timing of the weight measurement by the weight measuring unit, and FIG. 7 is a graph showing FIG. 5 and FIG. It is a figure for determining the optimal installation position of the air jet injection means that the time range in which the injection of the jet means affects the weighing accuracy does not overlap with the measurement timing of the weight measurement by the weight measurement unit.
FIG. 8 is a block diagram showing a control configuration of the weight sorting apparatus according to the first example configured on the assumption of the contents of the present example shown in the above-described drawings, and FIG. 9 is a weight sorting according to the second example. FIG. 10 is a block diagram showing the control configuration of the weight sorting device according to the third example.

1. 1. Configuration of Weight Sorting Device of This Example In the plan view of the weight sorting device of this example shown in FIG. 1, an xyz orthogonal coordinate system is also shown to show the arrangement and transport direction of this device. According to the system, the conveyance direction of the article to be weighed in this apparatus coincides with the x axis, and the z axis coincides with a vertical line perpendicular to the paper surface.

  As shown in FIG. 1, the weight sorting apparatus 1 of this example includes a weight measuring unit 2 and a sorting unit 3 arranged in parallel in the conveyance direction (x direction) of the object to be weighed. The first weight measuring unit 2 is provided in the vicinity of the first conveying means 4 (belt conveyor or the like) for conveying the item to be weighed and the first conveying means 4 and detects the entry of the item to be weighed to generate a detection signal. A detecting means 7 such as a photosensor for outputting; a weight measuring means 8 provided so as to support the first conveying means 4; and measuring the weight of an item to be weighed conveyed by the first conveying means 4. have. The transport length of the first transport means is L, and the transport speed is V. The rear sorting unit 3 includes a second transport unit 5 (such as a belt conveyor) provided adjacent to the front weight measurement unit 2 and a side of the second transport unit 5 (Y of the second transport unit 5). And air jet means 6 arranged in the direction adjacent portion.

  The air jet means 6 is disposed at a position separated from the boundary between the weight measuring section 2 and the sorting section 3 by a distance x along the transport direction (X direction) of the second transport means 5 of the sorting section 3. The air injection direction may be parallel to the Y axis and directed to the second conveying means 5 (FIG. 1A, when the inclination angle is 0 degree), or a predetermined direction with respect to the Y axis. The direction rotated by the obtuse angle (35 degrees in this example) to the downstream side in the transport direction of the second transport means 5 and can also be the direction facing the second transport means 5 (FIG. 1 (b), inclined For an angle of 35 degrees).

  Although it is possible to select whether or not the air jet means 6 is inclined with respect to the transport direction, in this example, the air injection is applied to the weight measurement with the air injection direction opposite to the weight measuring unit 2 as much as possible. An inclination angle (for example, 35 degrees as shown in FIG. 1B) was set so as to reduce the influence as much as possible.

  The air jet means 6 can eject air at a predetermined pressure guided from an air supply source (not shown) through an electromagnetic valve (not shown) for an arbitrary time. A control unit (personal computer PC or the like) (not shown) of this apparatus measures a measurement start signal sent by pressing an operation switch on the operation panel, and a sensor provided at the entrance of the first transport means 4 of the weight measuring unit 2 Air jet means by opening and closing the solenoid valve at an appropriate timing as needed in response to various signals such as a measurement signal from the weight measurement unit 2 and a detection signal of the weighing object to be detected and output 6 can be injected with air for a predetermined time. For example, when the result of measurement by the weight measuring unit 2 is NG (for example, when the weight is outside the specified range), a sensor is used to measure the object to be weighed that is being transported by the second transport means 5. By injecting air at an appropriate timing after the elapse of a predetermined time from the detection by, the item to be weighed can be excluded in a sorting direction different from the conveying direction (x direction) of the second conveying means 5.

FIG. 2 is a flow chart showing a simplified procedure for measuring the weight of the item to be weighed and for eliminating the air jet when the item to be weighed is an NG item.
As shown in step 1 (S1), the present apparatus is started by pressing an operation switch on the operation panel. As shown in step 2 (S2), when the detection means 7 (for example, photosensor) at the entrance of the first transport means 4 of the weight measuring unit 2 detects the item to be weighed, as shown in step 3 (S3), In response to the input of the signal from the detection means 7, the control means causes the weight measurement means 8 to start measuring the weight, and the weighing signal indicating the weight measurement result by the weight measurement means 8 is read into the control means (PC or the like).

  If this weight measurement result is out of the allowable weight range given to the control means in advance, the control means judges that the product to be measured is an NG product and excludes it from the line conveying direction as follows. . That is, as shown in step 4 (S4), after a predetermined time has elapsed from the output of the sensor (after 100 ms in the figure), the control means opens the electromagnetic valve and causes the air jet means 6 to start injecting air. As shown in (S5), after a predetermined time has elapsed (in the figure, after 100 ms, it can be changed by a program)), the solenoid valve is closed to stop air injection. In this way, by blowing air onto the item to be weighed for a predetermined time (100 ms in this example) at an appropriate timing according to the conveyance speed of the item to be weighed, the item to be weighed is conveyed by the second conveying means 5. Is removed from the second conveying means 5.

  In this example, the air injection force of the air jet means 6 can be set in proportion to the weight of the item to be weighed. That is, in the case of a relatively heavy object to be weighed, the control means can be set so that a relatively strong injection force is obtained, and in the case of a relatively light object to be weighed, a relatively weak injection force is obtained. it can.

2. About the influence of air injection in the weight selection apparatus 1 In the weight selection of the item to be weighed by the air jet means 6 described above, the weight measurement value varies due to the influence of the air jet injection. This is because the injected air causes adiabatic expansion and negatively affects the measurement at the start of injection (measured lighter than the actual weight), and then positively when the injection is stopped (actually Because it is heavier than the weight of.

  That is, as shown in FIG. 3, when the weight measurement timing of the weight measurement means 8 and the influence of the injection by the air jet means 6 are represented in the same figure with the time axis as the horizontal axis of a common scale, there is a certain weight measurement timing. When the NG determination is made for the above result, the air jet means 6 is driven at a certain timing after a predetermined time when the article to be weighed enters the range of the air jet means 6. Here, when the solenoid valve is opened (air jet injection start), the weighing accuracy is negatively affected, and when the solenoid valve is closed (air jet injection stopped), the weighing accuracy is positively affected. Therefore, if the weight measuring means 8 performs weight measurement on the subsequent objects to be weighed in a time zone where the weighing accuracy is affected, the measurement result is affected by the above-described effects and is an accurate result. Can't get.

  In the example shown in FIG. 3, the negative and positive effects on the weighing accuracy due to the start of air jet injection and the stop of air jet injection are shown as mountain-shaped waveforms, respectively. Yes, and within an allowable error range of weight measurement (for example, a range of ± 0.4 g in this example). That is, an error occurs in the weight measurement due to the air injection only during each fixed time when the injection is started and when the injection is stopped.

  Further, in this example, as described above, the air injection force of the air jet means 6 is set in proportion to the weight of the article to be weighed, but there is an error in the weight measurement due to the air injection force and the air injection. Since the influence force to be generated is considered to be proportional, the influence force that causes an error in the weight measurement due to the weight of the object to be weighed and the air injection is also proportional. Therefore, the accuracy that the air injection gives to the weight measurement is relatively constant regardless of the weight of the object to be weighed.

3. In the weight selection apparatus as described above, in the case where the air injection by the air jet means affects the weight measurement in the weight measuring unit, In order to reduce this effect as much as possible, the weight measurement is not performed at the timing when the air injection by the air jet means reaches the weight measurement section and affects the weight measurement, and the weight measurement is performed at other timings. Can be done. Here, considering the items to be controlled in order to achieve the above-mentioned object in relation to the phenomenon in which the air injection affects the weight measurement, the following three parameters related to each other can be cited. That is,
a. Installation position of air jet means (distance x from air jet means to weight measuring section)
b. Timing of weight measurement in the weight measuring unit c. Air injection timing in the air jet means (range of influence by air jet)
It is three.

If two of these three parameters are set as certain values, the remaining one can be determined so that the air injection by the air jet means does not affect the weight measurement in the weight measuring unit.
Hereinafter, a method for determining the condition that does not affect the weight measurement in the weight measuring unit by determining the remaining one from two of these three parameters, and a control for realizing such a method or control. The configuration of the means will be described in three parts in the following (1) to (3) according to the type of the last parameter to be finally calculated.

(1) When calculating the installation position of the air jet means or the distance x (parameter a) from the air jet means to the weight measuring unit 1) Control method FIG. 3 shows time (ms) on the horizontal axis and vertical axis on the vertical axis. An experiment conducted on three examples in which the influence (g) of the air injection by the air jet unit 6 on the weight measurement is different and the distance x between the weight measuring unit 2 and the air jet unit 6 in the X direction (conveyance direction) is different. (A) is x = 100 mm, (b) is x = 200 mm, and (c) is x = 400 mm. In this example, the length of the 2nd conveyance means 5 of the classification | selection part 3 in a back | latter stage is about 300-500 mm, The position of the air jet means 6 can be arbitrarily set thru | or changed within this range.

  In FIGS. 3A to 3C, the allowable error range in this example of the influence (g) of the influence of air injection by the air jet means 6 on the weight measurement is + It is shown as a hatched area on the minus side, and as described above, in this example, it is in the range of ± 0.4 g.

  Then, the time at which the curve of the graph goes out of the allowable error range and crosses the side boundary in the positive direction of time, that is, the influence start time on the weight measurement due to the start of air injection of the air jet means 6 is shown. A is assumed to be B, and the time at which the curve of the graph enters the range by crossing the -side boundary from outside the allowable error range in the positive direction of time, that is, -effect end time is assumed to be B. Similarly, the time at which the curve of the graph crosses the + side boundary from the allowable error range and goes out of the range in the positive direction of time, that is, the positive influence start time on the weight measurement due to the stop of air injection of the air jet means 6 And C is the time of the point where the curve of the graph crosses the positive side boundary from outside the allowable error range in the positive direction of time, that is, + the influence end time is D.

  From the experimental results shown in these graphs, the influence on the measurement accuracy due to the start and stop of air injection can be seen from the height of the waveform in each partial view, so that the X direction (conveyance) of the weight measuring unit 2 and the air jet means 6 (Direction) is smaller as the distance x is smaller, and smaller as the distance x is larger. Further, the interval between the −effect end time B and the + effect start time C can be understood from the interval between the − waveform and the + waveform in each minute figure, and the X direction (conveying direction) of the weight measuring unit 2 and the air jet means 6. ) Is shorter as the distance x is smaller, and longer as the distance x is larger.

  FIG. 4 shows the contents of FIG. 3 described above, with the distance x (mm) between the weight measuring unit 2 and the air jet means 6 on the horizontal axis and the elapsed time (ms) on the vertical axis. In FIG. 3, the straight lines indicated by symbols A, B, C, and D correspond to −effect start time A, −effect end time B, + effect start time C, and + effect end time D in FIG. Accordingly, a region α with a mesh line surrounded by straight lines A and B in FIG. 4 is an influence time range in which a negative influence can occur on the measurement, and a region with a mesh line surrounded by straight lines C and D is attached. β is an influence time range in which a positive influence can occur on the measurement.

  FIG. 5 shows the distance x (mm) between the weight measuring unit 2 and the air jet means 6 on the horizontal axis and the elapsed time (ms) on the vertical axis, as in FIG. The timing including the variation in the weight measurement by the measuring means 8 is indicated by the hatched range. In the figure, elapsed time 0 is the measurement timing of the first first item to be weighed, and thereafter the measurement timing of the second item to be weighed sequentially with the increase in elapsed time (moving upward on the vertical axis). Continuous with the measurement timing of the first item to be weighed.

  FIG. 6 is a graph in which FIGS. 4 and 5 described above are overlapped. According to this figure, in the weight sorting apparatus 1 of the present example, an influence time range α that is a range in which a negative influence can occur in weight measurement, and an influence time range β that is a range in which a positive influence can occur in the weight measurement, If the air jet means 6 is disposed at the distance x such that the region indicating the measurement timing including the variation in weight measurement by the weight measurement means 8 does not overlap with each other, the weight measurement is not adversely affected by the air jet means 6. It is understood that this can be done accurately.

  In this example, the influence time range α, which is a range where a negative influence can occur on the weight measurement, and the influence time range β, a range where a positive influence can occur on the weight measurement, and the variation in the weight measurement by the weight measuring means 8. A feature is that the air jet means 6 is arranged at the distance x so as not to overlap with the region indicating the timing range including.

  Specifically, as shown in FIG. 6, if the air jet means 6 is arranged in the range where the distance x is 200 to 300 mm, the influence time ranges α and + that can cause a negative influence on the weight measurement are produced. The possible influence time range β does not overlap the area indicating the timing of the weight measurement, and therefore the weight measurement is performed accurately without being adversely affected by the air jet means 6. Therefore, in this example, the air jet means 6 is set in the range where the distance x is 200 to 300 mm.

  However, as described above, in the weight sorting apparatus 1 of this example, the length of the second transport unit 5 of the sorting unit 3 is about 300 to 500 mm, for example. When the position of the air jet means 6 is too close to the rear end portion of the second transport means 5 due to the relationship with the position of the air jet means 6 indicated by the distance x, it is inclined 35 degrees as described above. The object to be weighed discharged obliquely forward in the conveying direction by the air jet from the set air jet means 6 may be excluded from a position further away from the conveying means installed at the subsequent stage in order to convey the OK product. It may not be possible, and it may be transported in the direction of an OK product on the transporting means at the subsequent stage.

  Therefore, the position of the air jet means 6 in the weight sorting apparatus 1 of this example is the influence time that can affect the weight measurement in the graph as shown in FIG. 6 showing the relationship between the distance x and the elapsed time from the start of measurement. The range and the area indicating the timing of weight measurement by the weight measuring means 8 are set to a distance x so as not to overlap each other, and the relationship between the total length of the second transport means 5 of the sorting unit 3 of the weight sorting apparatus 1 In consideration of the above, an appropriate upper limit is set so that the distance x does not come too close to the rear end portion of the second transport means 5 so that the air-jet means 6 can reliably remove the product to be weighed from the OK product transport line. It is preferable.

  As a specific example, when the total length of the second transport unit 5 is 345 mm and the angle of the air jet unit 6 is 35 degrees as described above, the air injection is performed from the experimental results when the distance x is 200 mm or more. There is a possibility that it will be difficult to reliably sort the extruded weighing object in the removal direction different from the conveyance direction of the OK product. Accordingly, when the distance x where the weight measurement timing does not overlap with the area where the weight measurement is affected is 100 to 300 mm, the distance x to be set is set to 100 to 200 mm in consideration of the above conditions. It is preferable.

2) Configuration of Control Unit FIG. 8 is a block diagram showing the configuration of the control unit and the like in the weight sorting apparatus of the present embodiment shown in FIG.
The control means 10 includes a preset transport speed V and transport length x of the first transport means 4, a predetermined initial position x _{0 of the} air jet means 6 and a predetermined propagation of air injection. It has parameter setting means 11 which is a storage means for setting and inputting the speed v and storing it. These parameters are determined in advance by actual measurement or experiment and set in the parameter setting means 11. Therefore, when used under different conditions, the propagation speed v of air injection needs to be experimentally determined anew and stored in the parameter setting means 11.

Further, the control means 10 includes a measurement timing calculation means 12 for calculating a weight measurement timing based on a preset transport speed V and a transport length L of the first transport means 4, and a preset air jet means. The influence time range in which the air jet means 6 affects the weight measurement by the weight measurement means 8 based on the arbitrary initial position x ₀ of 6 and the propagation velocity v of air injection determined in advance. And calculating means 13.

  Then, the control means 10 controls the air jet means 6 so that the measurement timing and the influence time range do not overlap each other from the measurement timing calculated by the measurement timing calculation means 12 and the influence time range calculated by the influence time range calculation means 13. A setting position calculation means 14 is provided for calculating and outputting the installation position x (or its range).

  By the way, in this example, the air jet means 6 is movable along the X direction which is the transport direction of the second transport means 5, and is moved along the same direction by the position setting means 15 provided with drive means such as a motor. Can be moved arbitrarily. Then, when information indicating an arbitrary installation position x calculated by the set position calculating means 14 is input to the position setting means 15, the position setting means 15 automatically drives the air jet means 6 to reach the set position x. Air jet means 6 is set.

  According to the weight sorting apparatus of this example, the start or stop of air injection by the air jet means 6 affects the measurement timing of the weight by the weight measurement unit 2 and the measurement of the weight of the object to be weighed by the weight measurement unit 2. Information for determining the position of the air jet unit 6 with respect to the weight measuring unit 2 is calculated so that the influence time range to be applied does not overlap. Based on this information, the position setting unit 15 moves the air jet unit 6 to an appropriate position. Since it can be set, the inconvenience that the accuracy of the weight measurement is lowered due to the change in the atmospheric pressure due to the injection of the air jet is avoided.

  In this example, the position setting means 15 is operated by the position information of the air jet means 6 calculated by the position setting means 15 to automatically move the air jet means, but the air jet calculated by the position setting means 15 is used. The position information of the means 6 may be displayed on a display means (not shown) so that the operator sees this and manually moves the air jet means to the position.

(2) When calculating the weight measurement timing (parameter b) in the weight measurement unit 1) Control method First, in order to prevent the air injection from affecting the weight measurement, the influence of local pressure fluctuations caused by the air injection is gravity. Considering that the time required to propagate to the measuring means and the distance x between the air jet means 6 and the weight measuring means 8 are proportional, this distance x and the jet timing of the air jet (the influence time range due to the air jet) If is constant, the timing of weight measurement may be changed. For example, in FIG. 6, when the position (x) of the air jet means on the horizontal axis is set to a predetermined value and the influence time range α or β by the air jet is constant, the influence time at the value of x What is necessary is just to change the timing of a weight measurement suitably so that it may not overlap with the range (alpha) or (beta). For example, at x = 200, the weight measurement timing does not overlap with the influence time range α or β in the example shown in FIG. 6, so there is no adverse effect on the weight measurement, but if x = 100, the second time Since the measurement timing and the influence time range α are overlapped, the weight measuring unit 2 is controlled so that the second weight measurement timing is advanced. By performing such control, the influence time range in which the influence of the air injection start and stop appears and the timing of the weight measurement do not coincide with each other, so that the weight measurement can be accurately performed.

  Specifically, the weight measurement of the weight measurement unit 2 is performed by the control unit 20 shown in FIG. 9 so that the influence time range in which the influence of the air injection start and stop appears and the timing of the weight measurement by the weight measurement unit 8 do not coincide. The weight measurement timing by means 8 may be adjusted.

2) Configuration of Control Unit FIG. 9 is a block diagram showing the configuration of the control unit 20 and the like in the weight sorting apparatus of the present embodiment shown in FIG.
The control means 20 is configured so that the air jet means 6 influences the weight measurement by the weight measuring section 2 based on an arbitrary initial position x ₀ of the air jet means 6 set in advance and the air injection propagation velocity v determined in advance. The influence time range calculating means 22 for calculating the influence time range that affects

Further, the control means 20, a first conveying speed V and the conveying length L of the conveying means 4 which is set in advance, receiving any input of installation position x ₁ of the air jet means 6 is set, further influence time range calculating means Based on the influence time range calculated by 22, there is a measurement timing calculation means 24 that calculates and outputs a weight measurement measurement timing that does not overlap the influence time range at the installation position x ₁ .

The control unit 20 includes a first conveying speed V and the conveying length L of the conveying means 4 which is set in advance, the propagation velocity of an arbitrary initial position x ₀ and previously obtained air injection of air jet means 6 which is set in advance It has parameter setting means 11 which is a storage means for setting and inputting v and storing it. These parameters are determined in advance by actual measurement or experiment and set in the parameter setting means 11.

The control means 20 has a setting position input means 23 of the air jet means 6 for inputting an arbitrary setting position x ₁ where the air jet means 6 is set. The setting position x ₁ is stored in the parameter setting means 21.

According to the weight sorting apparatus of the present example, the air jet means 6 has an influence depending on the influence time range in which the weight measurement by the weight measurement means 8 is affected and the installation position x ₁ of the air jet means 6 that is arbitrarily set. Since the measurement timing that does not overlap with the time range can be calculated and the weight measurement unit 2 can perform the weight measurement based on this information, the inconvenience that the accuracy of the weight measurement is reduced due to the atmospheric pressure change due to the air injection of the air jet means 6 is avoided. The

(3) When calculating the air injection timing (parameter c) of the air jet means 1) Control method First, in order to prevent the air injection from affecting the weight measurement, the influence of the local pressure fluctuation due to the air injection is a gravity measurement. Considering that the time required to propagate to the means 8 and the distance x between the air jet means 6 and the weight measuring means 8 are proportional, the distance x is constant (or the distance x is constant). If it cannot be changed), the injection start time is advanced, the injection end time is extended, or both are performed.

  For example, as shown in FIG. 7, the air injection start time is changed from a timing indicated by a solid line (in this case, it coincides with the weight measurement timing) to a slightly faster timing indicated by a broken line, and the air injection is stopped. The timing is changed from a timing represented by a solid line (in this case, it coincides with the weight measurement timing) to a slightly later timing represented by a broken line. By doing so, the influence time range in which the influence of the air injection start and stop appears and the timing of the weight measurement do not coincide with each other, so that the weight measurement is performed accurately.

  Specifically, the drive timing (opening) of the solenoid valve of the air jet means 6 by the control means is set so that the influence time range in which the influence of the air injection start and stop appears and the timing of the weight measurement by the weight measurement means 8 do not coincide. And closing) may be adjusted.

2) Control Unit FIG. 10 is a block diagram showing the configuration of the control unit 30 and the like in the weight sorting apparatus of the present embodiment shown in FIG.
The control unit 30 includes a measurement timing calculation unit 33 that calculates a measurement timing based on the conveyance speed V and the conveyance length L of the first conveyance unit 4 set in advance, and an arbitrary initial stage of the air jet unit 6 that is set in advance. Arbitrary installation at the measurement timing calculated by the measurement timing calculation means 33 in response to the input of the position x ₀ and the propagation velocity v of air injection determined in advance and the arbitrary installation position x ₁ of the air jet means 6 to be set. as the air jet means 6 is set at a position x ₁ is measured in weight gravimetric unit 2 is not affected, by calculating at least one of the air injection start timing and the air jet end timing of the air jet means 6 Injection timing calculation means 34 for outputting.

The control means 30, a conveying speed V and the conveying length L of the first conveying unit 4 that is set in advance, the propagation velocity of an arbitrary initial position x ₀ and previously obtained air injection of air jet means 6 which is set in advance It has parameter setting means 31 which is a storage means for setting and inputting v and storing it. These parameters are determined in advance by actual measurement or experiment and set in the parameter setting means 11.

The control means 30 has a setting position input means 32 of the air jet means 6 for inputting an arbitrary setting position x ₁ where the air jet means 6 is set. The setting position x ₁ is stored in the parameter setting means 31.

According to the weight sorting apparatus of this example, the air jet means 6 set at an arbitrary installation position x ₁ does not affect the weight measurement by the weight measurement means 8 at the weight measurement timing by the weight measurement unit 2. Since the air injection start or end timing of the air jet means 6 can be set appropriately, the inconvenience that the accuracy of the weight measurement is reduced due to the change in atmospheric pressure due to the air jet injection is avoided.

FIG. 1 is a schematic diagram showing a configuration example of a first embodiment of a weight sorting apparatus 1 according to the present invention. FIG. 2 is a flowchart showing a weight measurement procedure in the first embodiment. FIG. 3 is a graph showing the influence of the injection of the air jet unit 6 on the weighing accuracy for each interval between the air jet unit 6 and the weight measuring unit 2 in relation to the elapsed time from the start of injection in the first embodiment. is there. FIG. 4 is a graph showing the relationship between the distance between the air jet unit 6 and the weight measuring unit 2 and the elapsed time from the start of injection of the air jet unit 6 in the first embodiment. It is the figure which showed the influence time range which affects weighing accuracy. FIG. 5 is a graph showing the relationship between the distance between the air jet unit 6 and the weight measuring unit 2 and the elapsed time from the start of injection of the air jet unit 6 in the first embodiment. It is the figure which showed the measurement timing. FIG. 6 is a graph in which FIG. 4 and FIG. 5 are overlapped, and the time range in which the injection of the air jet means 6 affects the weighing accuracy does not overlap with the measurement timing of the weight measurement by the weight measurement unit 2. It is a figure which shows the optimal installation position of such an air jet injection means. FIG. 3 is a timing diagram of measurement and air jet injection showing a problem of weight measurement in the weight sorting apparatus 1. FIG. 8 is a block diagram illustrating a control configuration in the first example of the embodiment. FIG. 9 is a block diagram illustrating a control configuration in the second example of the embodiment. FIG. 10 is a block diagram illustrating a control configuration in the third example of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Weight sorting apparatus 2 ... Weight measuring part 3 ... Sorting part 4 ... 1st conveying means 5 ... 2nd conveying means 6 ... Air jet means 7 ... Detection means 8 ... Weight measuring means 10, 20, 30 ... Control means 11, 21, 31 ... parameter setting means 12, 33 ... measurement timing setting means 13, 22 ... influence time range calculation means 14 ... set position calculation means 15 ... position setting means 23, 32 ... set position input means 24 ... measurement timing calculation means 34 ... Injection timing calculation means

Claims (5)

A first conveying means (4) for conveying an item to be weighed; a detecting means (7) provided in the vicinity of the first conveying means for detecting the entry of the item to be weighed and outputting a detection signal; A weight measuring section (2) having weight measuring means (8) for measuring the weight of the item to be weighed being conveyed by the conveying means at a predetermined timing based on the detection signal;
The second conveying means (5) provided adjacent to the first conveying means, and the weighed goods being conveyed by the second conveying means are performed according to the result of measurement by the weight measuring unit. A sorting section (3) having air jet means (6) for sending in a direction different from the transport direction of the second transport means by air injection;
In a weight sorter equipped with
Measurement timing calculation means (12) for calculating a measurement timing based on a preset conveyance speed and conveyance length of the first conveyance means;
Influence of calculating an influence time range in which the air jet means influences the weight measurement by the weight measuring means based on an arbitrary initial position of the air jet means set in advance and a propagation velocity of air injection obtained in advance. Time range calculation means (13);
From the measurement timing and the influence time range, setting position calculation means (14) for calculating and outputting an installation position range of the air jet means so that the measurement timing and the influence time range do not overlap each other;
A weight sorting apparatus comprising: A first conveying means (4) for conveying an item to be weighed; a detecting means (7) provided in the vicinity of the first conveying means for detecting the entry of the item to be weighed and outputting a detection signal; A weight measuring section (2) having weight measuring means (8) for measuring the weight of the item to be weighed being conveyed by the conveying means at a predetermined timing based on the detection signal;
The second conveying means (5) provided adjacent to the first conveying means, and the weighed goods being conveyed by the second conveying means are performed according to the result of measurement by the weight measuring unit. A sorting section (3) having air jet means (6) for sending in a direction different from the transport direction of the second transport means by air injection;
In a weight sorter equipped with
Influence of calculating an influence time range in which the air jet means influences the weight measurement by the weight measuring unit based on a predetermined initial position of the air jet means set in advance and a propagation velocity of air injection obtained in advance. Time range calculation means (22);
A measurement timing calculating means (24) for calculating and outputting a measurement timing that does not overlap with the influence time range at an installation position of the air jet means set arbitrarily;
A weight sorting apparatus comprising: A first conveying means (4) for conveying an item to be weighed; a detecting means (7) provided in the vicinity of the first conveying means for detecting the entry of the item to be weighed and outputting a detection signal; A weight measuring section (2) having weight measuring means (8) for measuring the weight of the item to be weighed being conveyed by the conveying means at a predetermined timing based on the detection signal;
The second conveying means (5) provided adjacent to the first conveying means, and the weighed goods being conveyed by the second conveying means are performed according to the result of measurement by the weight measuring unit. A sorting section (3) having air jet means (6) for sending in a direction different from the transport direction of the second transport means by air injection;
In a weight sorter equipped with
Measurement timing calculation means (33) for calculating a measurement timing based on a preset conveyance speed and conveyance length of the first conveyance means;
Of the air injection start timing and the air injection end timing of the air jet means, the measurement of weight by the weight measuring unit is not affected by the air jet means set at an arbitrary installation position at the measurement timing. An injection timing calculating means (34) for calculating and outputting at least one of them;
A weight sorting apparatus comprising: The weight selecting apparatus according to claim 1, further comprising display means for displaying the output installation range of the air jet means (6). The weight selecting device according to claim 1, further comprising position setting means (15) for setting the position of the air jet means based on the output installation position range of the air jet means (6).

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