JP2005162407A - Weight sensing device for paper sheets - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weight sensing device for paper sheets etc. capable of sensing the weight of each sheet being transported. <P>SOLUTION: The weight sensing device is composed of a transport path 8 on which sheets 1 of paper are transported, a drive roller 4a and a pinch roller 4b installed on the transport path 8 for pinching and transporting the sheets 1, in which the pinch roller 4b is arranged in the confronting position with the transport path 8 interposed, a servo motor 10 to drive the drive roller 4a, and a control circuit 12 to change the sheet transporting speed in steps by adjusting the rotating speed of the drive roller 4a by the servo motor 10. When the sheet transporting speed is adjusted by the control circuit 12, the torque applied to the drive roller 4a owing to the weight of the sheet 1 transported changes, and therefore it is possible to sense the weight of the sheet by discriminating the torque with the control circuit 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a paper sheet weight detection device that detects the weight of a paper sheet such as a delivery item.

  For example, postal items such as “receipt receipts / account transfer notices” related to payment of usage charges from telephone companies include fixed-format account transfer notices, telephone (communication) statement breakdowns, and distributions such as Hello Information. It is enclosed and is composed of almost the same contents even if the delivery destination is different. With regard to postal items with the same contents, the contents are confirmed and the city / outside area is classified using a delivery sorter at the mail source. However, the delivery sorting machine has a problem that if the contents are loaded incorrectly or if the contents are missing in the middle, only the envelope is sorted and delivered.

In order to solve this problem, it is also practiced to measure the weight of each postal item processed by the delivery item sorting machine on a scale (see, for example, Patent Document 1). However, there is a problem that the processing speed does not increase when the weight of the mail piece is measured for each mail using the apparatus capable of measuring the weight described in Patent Document 1.
JP-A-10-339659 (first page, FIG. 1)

  The present invention has been made in order to solve the above-described problem, and the weight of the paper sheet being conveyed can be detected because the delivery sorting machine sorts the paper sheet with the content misloading or the content missing. An object of the present invention is to provide a paper sheet weight detection device.

  In order to achieve the above object, a paper sheet weight detection apparatus according to the present invention includes a transport unit that transports a paper sheet, a driving roller that is disposed on the transport unit and sandwiches and transports the paper sheet, and the driving unit. A pinch roller disposed at an opposing position via the conveying means of the roller, a conveying speed adjusting means for adjusting the conveying speed of the paper sheet by adjusting the rotational speed of the driving roller, and the conveying speed adjusting means When the conveyance speed of the paper sheet is adjusted by a torque discriminating means for discriminating torque applied to the drive roller by the paper sheet being conveyed, and based on the discrimination result of the torque discrimination means, And a weight detecting means for detecting the weight.

  According to the present invention, since the weight of a paper sheet being conveyed can be detected, it is possible to detect a misloading of the contents of a paper sheet such as a postal matter or a paper sheet lacking the contents.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a paper sheet weight detection apparatus according to an embodiment of the present invention. The paper sheet weight detection apparatus includes a take-out section 2 composed of take-out rollers and the like for separating and taking out paper sheets 1 one by one, a conveyance path 8 for conveying the taken-out paper sheets 1, and this conveyance path. 8, a weight detection unit 3 that detects the weight of the paper sheet 1 that is disposed and conveyed, and a first stacking unit 6 and a second stacking unit that stack the paper sheet 1 detected by the weight detection unit 3 7

  The weight detection unit 3 includes a pinch roller 3b disposed at a position opposed to the transport roller 3a via the drive roller 3a and the transport path 8 on the upstream side in the transport direction. The drive roller 3a and the pinch roller 3b take in the paper sheet 1 and decelerate the transport speed of the captured paper sheet 1 (acceleration / deceleration means of the transport speed adjusting means). Further, a sensor SC1 for detecting the transport position of the paper sheet 1 is disposed downstream of the drive roller 3a in the transport direction.

  The weight detection unit 3 includes a driving roller 4a that detects the conveying torque of the decelerated paper sheet 1, and a pinch roller 4b that is disposed at a position facing the conveying roller 4a via a conveying path 8 of the driving roller 4a. The rotational speed of the driving roller 4a is set, the servo motor 10 (driving speed adjusting means setting means) that drives the driving roller 4a, and the rotary encoder 11 (conveying speed) that measures the rotational speed of the servo motor 10 is set. A control circuit 12 for detecting the weight from the torque output from the servo motor 10 and the measuring means of the adjusting means) is arranged. Further, the sensor SC2 is arranged downstream in the transport direction of the driving roller 4a.

  Further, the weight detection unit 3 includes a driving roller 5a for returning the conveying speed of the paper sheet 1 decelerated by the driving roller 4a and the pinch roller 4b to the conveying speed before being decelerated, and conveying of the driving roller 5a. It has a pinch roller 5b disposed at a position facing the conveying roller 5a via the path 8 (acceleration / deceleration means of the conveying speed adjusting means).

  Next, the operation of the weight detection unit 3 will be described with reference to FIGS. 2A to 2D are diagrams for explaining the operation of the paper sheet weight detection unit 3. FIG. 3 is a diagram illustrating the conveyance speed / torque characteristics of the paper sheet weight detection unit.

In FIG. 2A, the sheet 1 is nipped and taken in by the drive roller 3a and the pinch roller 3b and is conveyed in the direction indicated by the arrow A at the conveyance speed V ₁ (first conveyance speed). The moment when the leading edge of the paper sheet reaches the sensor SC1 is shown (timing t0 in FIG. 3A).

  FIG. 2B shows the moment when the paper sheet 1 reaches the sensor SC1 and is conveyed at a constant speed, and the leading edge of the paper sheet 1 reaches the nip between the drive roller 4a and the pinch roller 4b (FIG. 3A). ) Timing t1).

FIG. 2C shows the moment when the leading edge of the paper sheet 1 reaches the sensor SC2 after being decelerated by the driving roller 4a and the pinch roller 4b after reaching the nip between the driving roller 4a and the pinch roller 4b (FIG. 3C). A) Timing t2). During the timing t1 of the timing t2, the conveying speed is controlled by the control circuit 12 until the conveyance speed V _{1 (first} conveying speed) from stepwise decelerated by the conveying speed V _{2 (second} conveying speed) (Acceleration / deceleration means of the conveyance speed adjusting means). That is, the control circuit 12 sets the rotation speed of the servo motor 11 a plurality of times every predetermined time so that the conveyance speed is substantially linearly reduced from the V1 to the conveyance speed V2 from the timing t1 to the time t2. Therefore actually reach 3 conveying speed V ₂ transport speed, as shown in (B) is decelerated stepwise from the conveying speed V _1.

Next, the operation of the torque T during the period from the timing t1 to t2 will be described. The torque T is such that the kinetic energy E1 received by the paper sheet 1 when the paper sheet 1 is nipped between the driving roller 3a and the pinch roller 3b and conveyed in the direction of the arrow A in the figure is the mass of the paper sheet 1 as m. Then, when the conveyance speed is V ₁ , the equation (1) is obtained.

E1 = (1/2) mV ₁ ² (J) (1)
Since the conveyance speed is decelerated from V ₁ (initial speed) to V ₂ , the fluctuation amount dE of the kinetic energy E1 in this case is as shown in Expression (2).

dE = (1/2) m (V ₁ −V ₂ ) ² (J) (2)
A torque T proportional to the kinetic energy dE is given to the drive roller 4a and the pinch roller 4b with the fluctuation amount dE of the kinetic energy shown by the mathematical formula (2). Accordingly, the torque T at this time can be expressed by Equation (3).

T = K ₁ · dE (N · m) (3)
T = K ₁ · (1/2) m (V ₁ −V ₂ ) ² (N · m) · (4)
K ₁ : Conversion coefficient when converting kinetic energy into torque.

  Next, the relationship between the mass of the paper sheet and the torque T will be described. When Expression (4) is a graph with time t on the horizontal axis and torque T on the vertical axis, it is as shown in FIG. 3C (a) (where V1> V2). Further, the mass m of the paper sheet 1 can be expressed by using the formula (5) from the formula (4).

m = K ₂ · 2T / (V ₁ −V ₂ ) ² (Kg) (5)
K ₂ : Conversion coefficient for converting torque T into mass.

  Formula (5) indicates that when the mass m of the paper sheet 1 is, for example, (1/2) m, which is half the normal mass, the torque T is (1/2) m. Therefore, for example, if (a) in FIG. 3 (C) is a torque characteristic curve when the mass is m, (b) in FIG. 3 (C) is a torque characteristic curve when the mass is (1/2) m. It shows that it becomes.

FIG. 2 (D) shows a moment when the leading end of the paper sheet 1 is after reaching the sensor SC2, has reached a predetermined time conveying speed to a nip and hold the V ₂ driving roller 5a and a pinch roller 5b ( 3A, since there is almost no change in the conveyance speed between the timings t2 and t3, the torque T is also substantially 0 (zero) from Equation (4) (timing t2, t3 in FIG. 3C). ).

Next, the driving roller 5a and the sheet 1 sandwiched pinch roller 5b is accelerated from the conveying speed V ₁ with the conveyance speed V ₂ in order to reverse the conveying speed (timing t3 in FIG. 3 (A), t4). At this time, since the speed fluctuation occurs again, the torque T based on Expression (4) is obtained. However, this time is generated in the rotational direction opposite to the direction of the torque T which the rotation direction is generated between the timing t1~t2 torque T with respect to the transport rollers 4a to accelerate the conveyance speed V ₁ from the conveying velocity V ₂ (Fig. 3 (C) timing t3, t4).

Thus, after reaching the transport speed of the drive roller 5a and the sheet 1 sandwiched pinch roller 5b is a conveying speed V ₁ was or first stacker 6, based on the weight detection result of the paper sheet 1 second 2 is accumulated in the accumulation unit.

  Next, the paper sheet weight detection means will be described. FIG. 4 is a diagram for explaining paper sheet weight detection. FIG. 4A is a diagram illustrating a change in the transport speed V of the paper sheet when the paper sheet is transported inside the weight detection unit 3, and is the same diagram as FIG. As described above, the characteristic curve of the torque T between the timing t1 and the timing t2 at which the conveyance speed V of the paper sheet is decelerated varies depending on the mass of the paper sheet. Therefore, the mass, that is, the weight of the paper sheet is detected by detecting the change in the torque T.

  4B is a torque characteristic curve of a paper sheet having a standard mass m, and FIG. 4B is a torque characteristic curve of a paper sheet having a mass (1/2) m. It is a curve. FIG. 4B (a) and FIG. 4B (b) determine the low level LLV (first set value), the high level HLV (second set value), and torque continuity. It is discriminated by the third set value shown below (torque discrimination means). FIG. 4C shows a weight detection signal which is a discrimination result in the case of FIG. 4B (a). Since (b) in FIG. 4B does not exceed the LLV, no weight detection signal is output. The discrimination means is expressed using mathematical formulas as follows.

  When the torque T is not less than the low level LLV (first set value) and not more than the high level HLV (second set value) (that is, the magnitude of the torque is within a predetermined range), the torque is further added. If the width time TW in the range is longer than the set width time TWS (that is, the time during which the torque is within the predetermined range is longer than the predetermined length), the weight detection result is good and the first stacking unit 6 If it is not included in the above range, the weight detection result is added to the second stacking unit 7 as an addition. The above results are shown in Equation (6) and Equation (7).

LLV ≦ T ≦ HLV (N · m) (6)
TWS ≦ TW (s) (7)
TWS: set width time TW: width time for which the torque T continuously satisfies the formula (6).

  It is possible to detect the weight of the paper sheet by setting the low level LLV, the high level HLV, and the set width time from the standard weight of the paper sheet to be processed. In the above embodiment, the first paper sheet is a normal paper sheet having no missing contents, and the second paper sheet is identified as a paper sheet having a small content and lacking weight (weight detection). means). In this way, the weight of the paper sheet can be detected.

  As described above, according to the present invention, when the transport speed of the transported paper sheet is adjusted, it is transported by detecting that the torque of the driving roller 4a obtained by the weight of the paper sheet changes. It is possible to detect the weight of the paper sheet, and to distinguish between the normal paper sheet and the paper sheet in which the contents are misloaded or the contents are missing.

The schematic block diagram of the weight detection apparatus of the paper sheets by the Example of this invention. The figure explaining operation | movement of the weight detection part of paper sheets. The figure explaining the conveyance speed and torque characteristic of the weight detection part of paper sheets. The figure explaining the weight detection means of paper sheets.

Explanation of symbols

SC1, SC2 Sensor 1 Paper sheet 2 Extraction unit 3 Weight detection unit 3a, 4a, 5a Drive roller 3b, 4b, 5b Pinch roller 6 First stacking unit 7 Second stacking unit 8 Transport path 10 Servo motor 11 Rotary encoder 12 Control circuit

Claims (5)

Conveying means for conveying paper sheets;
A driving roller disposed in the transporting unit and sandwiching and transporting the paper sheet, and a pinch roller disposed in an opposing position via the transporting unit of the driving roller;
A conveyance speed adjusting means for adjusting a conveyance speed of the paper sheets by adjusting a rotation speed of the driving roller;
Torque discriminating means for discriminating torque applied to the drive roller by the conveyed paper sheet when the conveying speed of the paper sheet is adjusted by the conveying speed adjusting means;
A weight detection device for paper sheets, comprising weight detection means for detecting the weight of the paper sheets based on a determination result of the torque determination means. The transport speed adjusting means is
Measuring means for measuring the rotational speed of the drive roller;
Setting means for setting the rotational speed of the drive roller;
A detecting means disposed in the vicinity of the drive roller for detecting the paper sheet that has been conveyed;
2. An acceleration / deceleration unit for decelerating or accelerating the rotation speed of the driving roller to a rotation speed set by the measurement unit and the setting unit based on a detection result of the detection unit. Paper sheet weight detection device. The acceleration / deceleration means includes
The paper sheet transported at the first transport speed by the transport means is sandwiched between the drive roller and the pinch roller, and the transport speed of the paper sheet is gradually reduced from the first transport speed. 3. The paper sheet weight detection device according to claim 2, wherein the second conveyance speed is set by acceleration. The torque determining means includes
When the transport speed of the paper sheet is adjusted by the transport speed adjusting means, the magnitude of torque applied to the drive roller by the transported paper sheet is within a predetermined range, and the torque is 2. The paper sheet weight detection apparatus according to claim 1, wherein the torque is determined by determining whether a time within the predetermined range is longer than a predetermined length. Conveying means for conveying paper sheets;
A driving roller disposed in the transporting unit and sandwiching and transporting the paper sheet, and a pinch roller disposed in an opposing position via the transporting unit of the driving roller;
A conveyance speed adjusting means for adjusting a conveyance speed of the paper sheets by adjusting a rotation speed of the driving roller;
Torque discriminating means for discriminating torque applied to the drive roller by the conveyed paper sheet when the conveying speed of the paper sheet is adjusted by the conveying speed adjusting means;
Sorting means for sorting the paper sheets based on the discrimination result of the torque discrimination means;
A paper sheet weight detection device comprising a first stacking unit and a second stacking unit for stacking the paper sheets sorted by the sorting unit.

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