DK178566B1

DK178566B1 - Combination weighing apparatus

Info

Publication number: DK178566B1
Application number: DKPA201370676A
Authority: DK
Inventors: Akinari Takeguchi
Original assignee: Ishida Seisakusho
Priority date: 2012-11-15
Filing date: 2013-11-13
Publication date: 2016-06-27
Also published as: JP6029945B2; JP2014098670A; DK201370676A1

Abstract

A combination weighing apparatus 1 includes a distribution table 2 and a control unit 8 that controIs the rotation of lhe distribution table 2. The distribution table 2 is provided wlth a gentle slope surface 2f, and has dircetivity in which an article supply amount in a direction toward the gentle slope surface 2f is .larger than those of the other directions. The control unit 8 repeatedly determines whether a pool hopper 4 of each of heads H1 to Hn is emply at every predetermined time T, integrates scores by giving a score to the head Hm corresponding to the pool hopper 4 determined as an empty state, and rotates the distribution table 2 so that the gentle slope surface 2f faces a high-integration-value head llj.

Description

TITLE OF THE INVENTION COMBINATION WEIGHING APPARATUS BACKGROUND OF THE INVENTION Field of the Invention

[0001] The present invention relates to a combination weighing apparatus.

Related Background Art

[0002] In recent years, a combination weighing apparatus that employs a rotary distribution unit has been widely distributed. For example, a combination weighing apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2010-175408 includes a distribution unit that is formed in an eccentrically conical shape and includes a steep slope surface and a gentle slope surface so as to distribute articles input from the upside thereof, plural heads that are disposed in a circular shape around the distribution unit, a detection unit that detects a shortage head in which the articles are not sufficiently supplied to a hopper thereof among the plural heads, and a control unit that drives the distribution unit in both right and left circumferential directions based on the detection result of the detection unit so as to position and stop the distribution unit so that the gentle slope surface faces the shortage head. In the combination weighing apparatus, when there are plural shortage heads, the control unit sequentially positions the distribution unit with respect to the plural shortage heads in order in which the driving amount of the distribution unit becomes minimal.

SUMMARY OF THE INVENTION

[0003] However, when a “strongly sticky article” such as a chicken is weighed by the combination weighing apparatus, it is not easy to equally supply the “strongly sticky article” to the hoppers arranged around the distribution unit, and it is difficult to realize a highly precise combination weighing operation.

[0004] An object of the present invention is to provide a combination weighing apparatus with high weighing precision by suppressing an unequal supply of an object to be weighed.

[0005] A combination weighing apparatus according to a first aspect of the present invention is a combination weighing apparatus in which plural heads each including a hopper weighing an object to be weighed are arranged in parallel in the circumferential direction, and includes a distribution table and a control unit that controls the rotation of the distribution table. The distribution table has a distribution function of sending an article to each of the heads and causes the distribution function to have directivity in which an article supply amount in a first direction is larger than those of the other directions. The control unit repeatedly determines whether the hopper of each head is empty at every predetermined time, integrates scores by giving a score to the head corresponding to the hopper determined as an empty state, and rotates the distribution table so that the first direction faces a high-integration-value head for the scores.

[0006] In the combination weighing apparatus, since the control unit recognizes the direction of supplying the object to be weighed to the hopper based on the score and orients the object to be weighed toward the direction, the unequal supply of the object to be weighed is suppressed. As a result, the weighing precision is improved.

[0007] A weighing apparatus according to a second aspect of the present invention is the weighing apparatus according to the first aspect, wherein the predetermined time is set to be shorter than a minimum time of a discharge interval of the object to be weighed.

[0008] For example, when there is an increase in the predetermined time for determining whether the hopper of each head is empty, an erroneous determination state is maintained for a long time such that the pool hopper that becomes empty after the object to be weighed is discharged therefrom is not determined as an empty state, and hence there is a possibility that the supply target of the object to be weighed may not be equally disposed. However, in the combination weighing apparatus, since the predetermined time is shorter than the minimum time of the discharge interval of the object to be weighed, the erroneous determination state is shortened by that much. As a result, the unequal supply of the object to be weighed is suppressed, and hence the weighing precision and the productivity are improved.

[0009] A combination weighing apparatus according to a third aspect of the present invention is the combination weighing apparatus according to the first aspect or the second aspect, wherein the control unit gives the score to the first head that has the empty hopper and gets the score among the plurality of heads even when the hopper of the second head adjacent to the first head is empty.

[0010] It needs to be considered that the rotary distribution table does not transport the object to be weighed in a pinpoint manner and that a certain variation occurs in the transportation direction. Accordingly, in the combination weighing apparatus, the control unit makes a state in which many hoppers standing by for input of an object to be weighed exist in a direction in which the integration value is high by taking information representing the empty state of the adjacent hopper and increasing the integration value of the score. Thus, even when the transportation direction varies to thereby deviate from the hopper having a high integration value, the object to be weighed is input to at least one of the hoppers standing by for input.

[0011] A combination weighing apparatus according to a fourth aspect of the present invention is the combination weighing apparatus according to the third aspect, wherein the control unit resets an integration value of the score of the first head when the object to be weighed is input to the hopper of at least one of the first head and the second head.

[0012] For example, when the integration value remains until the object to be weighed is input to the hopper of the high-integration-value head, the integration value of the specific head particularly increases, and hence there is a possibility that the supply target of the object to be weighed may be unequally disposed. However, in the combination weighing apparatus, since the integration value of the first head is reset even when the object to be weighed is input to the hopper of at least one of the first head and the second head adjacent thereto, it is possible to prevent the integration value of the specific hopper from being particularly increased.

[0013] A combination weighing apparatus according to a fifth aspect of the present invention is the combination weighing apparatus according to the first aspect, wherein the control unit stops the distribution table after rotating the distribution table so that the first direction faces a high-integration-value head and resets the integration value of the head after a predetermined stop time elapses.

[0014] For example, when the integration value remains until the object to be weighed is input to the hopper of the “high-integration-value head”, the integration value of the specific head particularly increases, and hence there is a possibility that the supply target of the object to be weighed may be unequally disposed. However, in the combination weighing apparatus, since the integration value of the head facing the first direction is reset after a predetermined stop time elapses, it is possible to prevent the integration value of the specific head from being particularly increased.

[0015] A combination weighing apparatus according to a sixth aspect of the present invention is the combination weighing apparatus according to the fifth aspect, wherein the stop time of the distribution table is changeable.

[0016] Since the supply speed needs to be changed in accordance with the type of the object to be weighed, the distribution table stop time needs to be also changed in accordance with the change in the supply speed. In the combination weighing apparatus, since the distribution table stop time is changeable, a user may conveniently use the combination weighing apparatus.

[0017] A combination weighing apparatus according to a seventh aspect of the present invention is the combination weighing apparatus according to the first aspect, wherein the control unit resets the integration value of the score of the first head when the object to be weighed is input to the hopper of at least one of the first head and the second head adjacent to the first head among the plurality of heads.

[0018] For example, when the integration value remains until the object to be weighed is input to the hopper of the high-integration-value head, the integration value of the specific head particularly increases, and hence there is a possibility that the supply target of the object to be weighed may be unequally disposed. However, in the combination weighing apparatus, since the integration value of the first head is reset even when the object to be weighed is input to the hopper of at least one of the first head and the second head adjacent thereto, it is possible to prevent the integration value of the specific hopper from being particularly increased.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Fig. 1 is a side view illustrating a combination weighing apparatus according to an embodiment of the present invention.

[0020] Fig. 2 is a top view illustrating the combination weighing apparatus.

[0021] Fig. 3 is a control block diagram illustrating the combination weighing apparatus.

[0022] Fig. 4A is a control flowchart illustrating an operation until an article supply target is determined.

[0023] Fig. 4B is a control flowchart illustrating an operation after the article supply target is determined.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. Furthermore, the embodiments below are specific examples of the present invention, and do not limit the technical scope of the present invention.

[0025] (1) Configuration of combination weighing apparatus 1

Fig. 1 is a side view illustrating a combination weighing apparatus 1 according to an embodiment of the present invention. Further, Fig. 2 is a top view illustrating the combination weighing apparatus 1. In Figs. 1 and 2, the combination weighing apparatus 1 includes a distribution table 2, plural heads H that are arranged around the distribution table 2, a collection discharge chute 70, and a control unit 8 (see Fig. 3). Each head H includes a supply unit 3, a pool hopper 4, and a weighing hopper 5. Furthermore, in this embodiment, an example of the combination weighing apparatus 1 equipped with twelve arranged heads H will be described.

[0026] An object to be weighed (hereinafter, referred to as an “article M”) is transported to the upper side of the distribution table 2 by a transportation conveyor 150 and is dropped onto the distribution table 2. The article M is, for example, an article M such as a chicken that is smooth and highly sticky.

[0027] The supply unit 3 supplies the article M to the pool hopper 4 disposed at the downstream side of the supply unit 3. The pool hopper 4 is equipped with a gate 41. The pool hopper 4 temporarily stores the article M supplied from the supply unit 3.

[0028] The weighing hopper 5 is provided below the pool hopper 4. The weight of the article M that is input from the pool hopper 4 to the weighing hopper 5 is detected by a load cell 11. The weighing hopper 5 is equipped with a gate 51. The collection discharge chute 70 is disposed below the gate 51. The collection discharge chute 70 integrates the weighing values of the articles M respectively detected by the load cells 11 so that the integration value of the whole articles M becomes a target value or a value close to the target value, and drops the articles M to a downstream packaging device 90.

[0029] (2) Specific configuration (2-1) Distribution table 2

The distribution table 2 distributes the article M supplied from the transportation conveyor 150 to the supply unit 3. The distribution table 2 includes a table portion 2a that is formed in a conical shape of which the apex V is eccentrically disposed and a rotational driving portion 2b that rotationally drives the table portion 2a. The drive source of the rotational driving portion 2b is a stepping motor. Since the table portion 2a is formed so that the apex is eccentrically disposed, the table portion 2a includes a gentle slope surface 2f having a long generator and a steep slope surface 2e having a short generator, and the rotation center is set on the gentle slope surface 2f.

[0030] The control unit 8 controls the rotational driving portion 2b so that the rotational driving portion 2b is turned on and off or is rotated at a predetermined constant speed. The control unit 8 rotates the table portion 2a at a speed that is set in advance in accordance with the type of the article M by the rotational driving portion 2b. Furthermore, the rotation speed of the table portion 2a may be controlled so that the rotation speed increases or decreases in accordance with the supply amount of the article M.

[0031] The article M slides on the slope surface so as to be supplied to the supply unit 3 by the inclination and the centrifugal force of the rotating table portion 2a.

[0032] (2-2) Supply unit 3

The supply unit 3 includes a trough 31 and two spiral members 32 and 33. The trough 31 has a shape in which an upper half portion of a cylinder is substantially cut out. Accordingly, the trough 31 includes a bottom surface that is defined as the inner surface of the cylinder and an opened upper surface. Further, the outer circumferential edge of the distribution table 2 is located directly above the supply unit 3, and the article M that is discharged from the outer circumferential edge of the distribution table 2 is delivered to the supply unit 3.

[0033] Further, the trough 31 is disposed in a forward inclined posture so that the outer end is located at the lower side in relation to the inner end. Thus, the bottom surface of the trough 31 becomes a down slope in a direction from the inner end of the bottom surface to the outer end thereof.

[0034] The spiral members 32 and 33 are rotatably disposed on the bottom surface of the trough 31. The respective inner ends of the spiral members 32 and 33 are fixed to the rotation shaft 34. When the rotation shaft 34 is rotationally driven by a spiral member rotational driving portion 30, the spiral members 32 and 33 are rotationally driven in a direction in which the article M inside the trough 31 is extmded from the inner end of the trough 31 to the outer end thereof.

[0035] (2-3) Pool hopper 4

The pool hopper 4 temporarily stores the article M supplied from the supply unit 3. The pool hoppers 4 are disposed in a circular shape below the supply units 3. The respective pool hoppers 4 are disposed at the same interval.

[0036] The pool hopper 4 is formed in a cylindrical shape that includes an input port and a discharge port. The input port is provided at the upper portion of the pool hopper 4 and the discharge port is provided at the lower portion of the pool hopper 4. The discharge port of each pool hopper 4 is equipped with the gate 41, and the discharge port of the pool hopper 4 is opened and closed by the gate 41. Specifically, the discharge port is opened and closed by the gate 41 using a stepping motor 42, and is controlled by the control unit 8 so that the discharge port is opened and closed. The pool hopper 4 opens the gate 41 and supplies the article M to the weighing hopper 5 belonging to the same head H.

[0037] (2-4) Weighing hopper 5

The weighing hopper 5 weighs the article M supplied from the pool hopper 4 using the load cell 11. The weighing hopper 5 is disposed below the gate 41 of the pool hopper 4.

[0038] The weighing hopper 5 includes an input port and a discharge port. The input port is provided at the upper portion of the weighing hopper 5, and the discharge port is provided at the lower portion of the weighing hopper 5. The discharge port of the weighing hopper 5 is equipped with the gate 51, and the discharge port of the weighing hopper 5 is opened and closed by the gate 51. Specifically, the discharge port is opened and closed by the gate 51 using a stepping motor 52, and is controlled by the control unit 8 so that the discharge port is opened and closed. The weighing hopper 5 holds the article M when the gate 51 is closed, and drops the article M to the collection discharge chute 70 when the gate 51 is opened.

[0039] (2-5) Collection discharge chute 70

The collection discharge chute 70 is disposed below the weighing hopper 5. The collection discharge chute 70 includes an input port 71 and a discharge port 72. The input port 71 is provided at the upper portion of the collection discharge chute 70. The discharge port 72 is provided at the lower portion of the collection discharge chute 70. The center position of the discharge port 72 matches the center position of the input port 71. The collection discharge chute 70 collects the articles M dropped from the weighing hopper 5, and then discharges the collected articles M toward the packaging device 90 that is disposed at the downstream side.

[0040] (2-6) Control unit 8

Fig. 3 is a control block diagram illustrating the combination weighing apparatus 1. In Fig. 3, the control unit 8 includes a CPU 81 and a memory 82. The control unit 8 is connected to the transportation conveyor 150, the rotational driving portion 2b, the stepping motor 42 for opening and closing the gate 41, the stepping motor 52 for opening and closing the gate 51, the load cell 10 mounted on each pool hopper 4, the load cell 11 mounted on each weighing hopper 5, and the spiral member rotational driving portion 30.

[0041] A weighing signal P10 output from the load cell 10 is input to the control unit 8. Further, a weighing signal Pll output from the load cell 11 is input to the control unit 8.

[0042] The control unit 8 outputs a driving signal PI5 for driving the transportation conveyor 150. Further, the control unit 8 outputs a driving signal P30 for driving the spiral members 32 and 33. Further, the control unit 8 outputs a driving signal P4 for opening and closing the gate 41 of the pool hopper 4 of each head H. Further, the control unit 8 outputs a driving signal P5 for opening and closing the gate 51 of the weighing hopper 5 of each head H.

[0043] (3) Operation of discharging article M from distribution table 2 to each head H

The distribution table 2 rotates about the rotation center C. When the article M is input from the transportation conveyor 150 onto the gentle slope surface 2f, the article M slides on the gentle slope surface 2f in a direction moving away from the apex, and is discharged from the distribution table 2.

[0044] In this way, the direction in which the article M is discharged from the distribution table 2 is substantially defined by the direction in which the gentle slope surface 2f of the distribution table 2 faces. Accordingly, when the direction of the gentle slope surface 2f is defined so that the article M is discharged toward the desired head H by the driving in the circumferential direction and the article M is dropped onto the gentle slope surface 2f, the article M may be supplied from the distribution table 2 to the supply unit 3 of the head H.

[0045] In the combination weighing apparatus 1, the distribution table 2 may be driven in both directions of CW (clockwise rotation) and CCW (counter-clockwise rotation), and the position of the distribution table 2 may be defined so that the gentle slope surface 2f faces the arbitrary head H. For example, the article M is supplied to the head H10 at the position of the gentle slope surface 2f of Fig. 2.

[0046] (4) Operation of combination weighing apparatus 1 (4-1) Basic operation

The control unit 8 specifies the pool hopper 4 that does not store the article M based on the weighing signal P10 input from the load cell 10 of each pool hopper 4.

[0047] Furthermore, in the example below, for convenience of the description, it is assumed that the pool hopper 4 of the head HI is specified as the pool hopper 4 that does not store the article M.

[0048] The control unit 8 positions the distribution table 2 so that the gentle slope surface 2f faces the head HI by driving the distribution table 2 based on the driving signal P2.

[0049] The control unit 8 discharges the article M by driving the transportation conveyor 150 based on the driving signal PI5. The article M is dropped on the gentle slope surface 2f, slides on the gentle slope surface 2f, and is discharged from the distribution table 2, so that the article M is supplied to the supply unit 3 of the head HI.

[0050] In the supply unit 3, the article M may be efficiently transported by the mutual interaction of the pressing operation from the rear performed by the spiral members 32 and 33 and the sliding operation performed by the down slope. Further, in a state where the spiral members 32 and 33 are stopped without being rotationally driven, the spiral members 32 and 33 serve as stoppers that prevent the unintended sliding action of the article M on the slope. Accordingly, when the spiral members 32 and 33 are rotationally driven in the supply unit 3 of the head H that does not store the article M in the pool hopper 4 and the spiral members 32 and 33 are not rotationally driven in the supply unit 3 of the head H that stores the article M in the pool hopper 4, the article M may be supplied only to the pool hopper 4 to which the article needs to be supplied.

[0051] The control unit 8 specifies the weighing hopper 5 that does not store the article M based on the weighing signal Pll input from the load cell 11 of each head H. Then, the control unit 8 supplies the article M stored in the pool hopper 4 to the weighing hopper 5 by opening the gate 41 of the head H that does not store the article M in the weighing hopper 5 based on the driving signal P4.

[0052] Each load cell 11 of the heads HI to HI2 weighs the articles M stored in the weighing hopper 5, and outputs the weighing signal Pll as the weighing result. The weighing signal Pll is input to the control unit 8, and the control unit 8 stores the weighing value of the articles M corresponding to each of the heads HI to HI2.

[0053] The control unit 8 obtains the combination of the weighing hoppers 5 which realize a weight value that matches or is closest to a target weight among all weighing hoppers 5 storing the articles M in terms of a calculation. Then, in the weighing hoppers 5 involved with the combination, the gates 51 are opened by the driving signal P5 so as to discharge the articles M stored in the weighing hoppers 5. The articles that are discharged from the weighing hoppers 5 are collected by the collection discharge chute 70, and are discharged toward the packaging device 90.

[0054] (4-2) Determination of supply order and supply operation based on the supply order

In the description above, for convenience of the description, an example has been described in which only one pool hopper 4 is specified as the pool hopper 4 that does not store the article M. However, since the articles M may not be actually stored in plural pool hoppers 4, the supply order is obtained for the plural pool hoppers 4 that do not store the articles M, and the articles M are supplied according to the supply order.

[0055] The control unit 8 repeatedly determines whether the pool hopper 4 of each of the heads HI to HI2 is empty at every predetermined time T when obtaining the supply order, integrates scores by giving a score to the head Hm corresponding to the pool hopper 4 determined as an empty state, and rotates the distribution table 2 so that the article M is delivered to a high-integration-value head Hj. By this operation, the article M may be first supplied to a region having many heads H to which the article M needs to be supplied. Hereinafter, this supply operation will be described with reference to the control flowchart. Furthermore, the predetermined time T may be set as a combination weighing cycle start signal interval. Further, the present invention is not limited thereto, and the predetermined time T may be set as a hopper discharge signal interval.

[0056] Fig. 4A is a control flowchart illustrating an operation until the supply target of the article M is determined, and Fig. 4B is a control flowchart illustrating an operation after the supply target is determined.

[0057] (4-2-1) Description of steps SI to S10

First, in step SI, the control unit 8 returns the position of the distribution table 2 to the original position as illustrated in Fig. 4A. This operation is performed even when the precedent stop position is the original position.

[0058] Next, in step S2, the control unit 8 sets the integration value of each of the twelve heads HI to HI2 to 0, and stores the integration values in the memory. Subsequently, in step S3, the control unit 8 starts a time keeping operation by turning on a first timer.

[0059] In step S4, the control unit 8 determines whether the elapsed time from the activation of the first timer of step S3 reaches the predetermined time T. When the elapsed time reaches the predetermined time T, the control unit 8 moves the routine to step S5. Meanwhile, when the elapsed time does not reach the predetermined time T yet, the control unit 8 keeps monitoring the elapsed time in step S4.

[0060] Furthermore, the predetermined time T is set to be shorter than the minimum time of the discharge interval of the article M. This is because of the following reason. When there is an increase in the predetermined time for determining whether the pool hopper 4 of each of the heads HI to HI2 is empty, an erroneous determination state is maintained for a long time such that the pool hopper 4 that becomes empty after the article M is discharged therefrom is not determined as an empty state, and hence there is a possibility that the supply target of the article M may not be equally disposed.

[0061] However, in the combination weighing apparatus 1 of this embodiment, since the predetermined time T is set to be shorter than the minimum time of the discharge interval of the article M, the erroneous determination state may be shortened by that much.

[0062] In step S5, the control unit 8 gives a score 1 to the head H including the empty pool hopper 4. For example, when the pool hopper 4 of the m-th head Hm is empty, the integration value of the head Hm becomes 1.

[0063] In step S6, the control unit 8 determines whether the pool hopper 4 of the head Hm-1 adjacent to the head Hm is empty, and moves the routine to step S7 when the pool hopper 4 of the head Hm-1 is empty or moves the routine to step S71 when the pool hopper 4 of the head Hm-1 is not empty.

[0064] In step S7, the control unit 8 gives a score 1 to the head Hm. Since the last integration value of the head Hm is 1, the integration value of the head Hm becomes 2.

[0065] In step S8, the control unit 8 determines whether the pool hopper 4 of the head Hm+1 adjacent to the head Hm is empty, and moves the routine to step S9 when the pool hopper 4 of the head Hm+1 is empty or moves the routine to step S91 when the pool hopper 4 of the head Hm+1 is not empty.

[0066] In step S9, the control unit 8 gives a score 1 to the head Hm. Since the last integration value of the head Hm is 2, the integration value of the head Hm becomes 3.

[0067] In step S10, the control unit 8 specifies the head Hj having a maximum integration value among the twelve heads HI to H12.

[0068] (4-2-2) Description of step S6 —»· step S71 —»· steps S8 to S10 On the other hand, when the control unit 8 determines that the pool hopper 4 of the head Hm-1 adjacent to the head Hm is not empty in step S6, the control unit 8 moves the routine to step S71 so as to reset the integration value of the heads Hm-2, Hm-1, and Hm and moves the routine to step S8.

[0069] When the control unit 8 determines that the pool hopper 4 of the head Hm+1 adjacent to the head Hm is empty in step S8, the control unit 8 moves the routine to step S9 so as to give a score 1 to the head Hm. Since the last integration value of the head Hm is reset to 0, the integration value of the head Hm becomes 1.

[0070] Then, in step S10, the control unit 8 specifies the head Hj having a maximum integration value in the twelve heads HI to HI2.

[0071] (4-2-3) Description of steps S6 to S8 —»· step S91 —»· step S10 When the control unit 8 determines that the pool hopper 4 of the head Hm-1 adjacent to the head Hm is empty in step S6, the control unit 8 moves the routine to step S7 so as to give a score 1 to the head Hm. Since the last integration value of the head Hm is 1, the integration value of the head Hm becomes 2.

[0072] When the control unit 8 determines that the pool hopper 4 of the head Hm+1 adjacent to the head Hm is not empty in step S8, the control unit 8 moves the routine to step S91 so as to reset the integration value of the heads Hm, Hm+1, and Hm+2.

[0073] Then, in step S10, the control unit 8 specifies the head Hj having a maximum integration value in the twelve heads HI to HI2.

[0074] (4-2-4) Description of step S6 —» step S71 —» step S8 —» step S91 —»· step S10

When the control unit 8 determines that the pool hopper 4 of the head Hm-1 adjacent to the head Hm is not empty in step S6, the control unit 8 moves the routine to step S71 so as to reset the integration value of the heads Hm-2, Hm-1, and Hm, and moves the routine to step S8.

[0075] When the control unit 8 determines that the pool hopper 4 of the head Hm+1 adjacent to the head Hm is not empty in step S8, the control unit 8 moves the routine to step S91 so as to reset the integration value of the heads Hm, Hm+1, and Hm+2.

[0076] Then, in step S10, the control unit 8 specifies the head Hj having a maximum integration value in the twelve heads HI to HI2.

[0077] (4-2-5) step Sll to step S19

In step Sll, the control unit 8 rotates the distribution table 2 so that the gentle slope surface 2f of the distribution table 2 faces the head Hj. The power of the rotational driving portion 2b of the distribution table 2 is generated by a stepping motor. The position of each head corresponding to which number of pulses of the driving pulses of the stepping motor from the original position is stored in the memory in advance. Thus, the control unit 8 may calculate the number of pulses necessary for the position of the head Hj from the head position until just before the gentle slope surface 2f of the distribution table 2 faces.

[0078] In step SI2, the control unit 8 determines whether the gentle slope surface 2f of the distribution table 2 faces the head Hj. The control unit 8 may perform this determination depending on whether the number of necessary pulses is all output to the stepping motor of the rotational driving portion 2b after calculating the number of pulses necessary to the position of the head Hj from the head position until just before the gentle slope surface 2f of the distribution table 2 faces.

[0079] The control unit 8 moves the routine to step S13 when it is determined that the gentle slope surface 2f of the distribution table 2 faces the head Hj or stays in step S12 so as to keep monitoring whether the gentle slope surface 2f of the distribution table 2 faces the head Hj when it is determined that the gentle slope surface 2f of the distribution table 2 does not face the head Hj.

[0080] In step SI3, the control unit 8 stops the rotation of the distribution table 2 and moves the routine to step S14. Subsequently, the control unit 8 starts a time keeping operation by turning on a second timer in step S14.

[0081] In step SI5, the control unit 8 determines whether the elapsed time from the activation of the second timer in step S14 reaches the stop time S, and moves the routine to step S16 when the elapsed time reaches the stop time S or stays in step S15 so as to keep monitoring the elapse time when the elapsed time does not reach the stop time S yet.

[0082] Furthermore, in this embodiment, the stop time of the distribution table 2 is changeable so as to correspond to a change in the stop time S of the distribution table 2 in accordance with a change in the supply speed of the article M.

[0083] In step SI6, the control unit 8 resets the integration value of the head Hj and moves the routine to step S17.

[0084] In step S17, the control unit 8 resets the first timer and the second timer and moves the routine to step SI8. In step SI8, the control unit 8 determines whether an operation stop instruction is issued and returns the routine to step S3 when it is determined that the operation stop instruction is not issued or moves the routine to step S19 so as to stop the operation when it is determined that the operation stop instruction is issued.

[0085] (5) Characteristic (5-1)

The combination weighing apparatus 1 includes the distribution table 2 and the control unit 8 that controls the rotation of the distribution table 2. The distribution table 2 is provided with the gentle slope surface 2f and has directivity in which the article supply amount in the direction toward the gentle slope surface 2f is larger than those in the other directions. The control unit 8 repeatedly determines whether the pool hopper 4 of each of the heads HI to HI2 is empty at every predetermined time T, integrates scores by giving a score to the head Hm of the pool hopper 4 determined as an empty state, and rotates the distribution table 2 so that the gentle slope surface 2f faces the high-integration-value head Hj. Since the control unit 8 may recognize a region where the number of the pool hoppers 4 to which the articles M need to be supplied is large based on the score and orients the articles M toward the region, it is possible to suppress the unequal supply of the articles M. As a result, the weighing precision is improved.

[0086] (5-2)

Since the predetermined time T is set to be shorter than the minimum time of the discharge interval of the article M, it is possible to shorten the time of the “erroneous determination in which the empty pool hopper 4 is determined as a non-empty state”. As a result, the unequal supply of the article M is suppressed, and hence the weighing precision and the productivity are improved.

[0087] (5-3)

The control unit 8 makes a state in which many pool hoppers 4 waiting for the input of the articles M exist in a direction in which the integration value is high by taking information representing the empty state of the adjacent pool hopper 4 and increasing the integration value of the score. Thus, even when the distribution direction varies to thereby deviate from the pool hopper 4 of the head H having a high integration value, the article M is input to at least one of the pool hoppers 4 standing by for input.

[0088] (5-4)

In order to prevent the integration value of the score of the specific head from being particularly increased, the control unit 8 resets the integration value of the head Hm even when the article M is input to the pool hopper 4 of the head Hm+1 adjacent to the head Hm having the empty pool hopper 4.

[0089] (5-5)

Further, in order to prevent the integration value of the score of the specific head from being particularly increased, the control unit 8 stops the distribution table 2 after rotating the distribution table 2 so that the gentle slope surface 2f faces the head Hj having a high integration value, and resets the integration value of the head Hj after a predetermined stop time S elapses.

[0090] (5-6)

The supply speed needs to be changed in accordance with the type of the article M, and the stop time S of the distribution table 2 needs to be also changed in accordance with a change in the supply speed. In the combination weighing apparatus, since the stop time S of the distribution table 2 is changeable, a user may conveniently use the combination weighing apparatus.

[0091] (6) Others

In the above-described embodiments, a combination weighing cycle start signal interval may be employed as the predetermined time T. This is because of the following reason. In the combination weighing cycle start signal, the origin at which the article is discharged from the hopper so that the hopper becomes empty is an interlocking signal or a spontaneous signal, and hence the basis of the time becomes the origin of the interlocking signal or the like.

[0092] Further, the predetermined time T is not limited to the combination weighing cycle start signal interval, and may be a hopper discharge signal interval. This is because the origin at which the article is discharged from the hopper so that the hopper becomes empty is also a discharge signal.

[0093] Further, the predetermined time T may be changeable. For example, it is possible to determine “whether the pool hopper 4 of each head H is empty” after the time after the next combination weighing cycle start signal is generated instead of determining “whether the pool hopper 4 of each head H is empty” after the next combination weighing cycle start signal is generated at a time point elapsing by a predetermined time from the generation of the combination weighing cycle start signal, instead of every combination weighing cycle. Further, the predetermined time T may be an indefinite interval.

[0094] In the combination weighing apparatus according to the present invention, since the control unit recognizes the direction of supplying the object to be weighed to the hopper based on the score and orients the object to be weighed toward the direction, the unequal supply of the object to be weighed is suppressed. As a result, the weighing precision is improved.

[0095] As described above, according to the present invention, the combination weighing apparatus is useful to determine a supply order in an apparatus that supplies articles to plural supply targets.

Claims

A combination weighing apparatus (1) wherein a plurality of heads (H), each comprising a container (4) weighing an object to be weighed, is arranged parallel in the circumferential direction, the combination weighing apparatus (1) comprising: a distribution table (2) which has a distribution function that sends an article (M) to each of the heads (H) and causes the distribution function to have a directional effect where an article supply quantity in a first direction is greater than those in the other directions; and a control unit (8) controlling the rotation of the distribution scheme (2), characterized in that the control unit (8) repeatedly determines whether the container (4) in each of the heads (H) is empty at each predetermined time, and for each head (H ) either gives a result to the head (H) corresponding to the container (4) determined as empty, and obtains an integration value for the head (H) corresponding to the container (4) determined as empty by integrating the results given to the head (H) corresponding to the container (4) determined as empty, or resets the integration value for the head (H) corresponding to the container (4) not determined as empty and the integration values for the heads (H) raised by the head (H) corresponding to the container (4) not determined as empty, and wherein the control unit (8) rotates the distribution table (2) so that the first direction faces the head (H) with the highest integration value among the plurality of heads (H).

Combination strainer (1) according to claim 1, wherein the predetermined time is set to be shorter than a minimum time for an emptying interval for the object to be weighed.

Combination weighing apparatus (1) according to claim 1 or 2, wherein the control unit (8) gives the result to the first head (H) having an empty container (4) even when the container (4) in the second head (H) is mounted of the first head (H) is determined as blank.

Combination weighing apparatus (1) according to any one of claims 1 to 3, wherein the control unit (8) stops the distribution table (2) after rotating the distribution scheme (2) so that the first direction faces the head (H) with the highest integration value and resets the integration value for the head (H) after a predetermined stop time has elapsed.

The combination weighing apparatus (1) according to claim 4, wherein the stopping time of the distribution table (2) is variable.