Combination weigher

Abstract

To provide a combination weigher that is configured so that objects to be weighed supplied to the dispersion feeder are dispersed and transported to a straight feeder group arranged radially around the dispersion feeder, and the objects to be weighed conveyed by each straight feeder are sent to the weighing hopper via the supply hoppers, the combination weigher being capable of sending objects that tend to clump together evenly to the supply hoppers.SOLUTION: The combination weigher includes: multiple shutter mechanisms 34 capable of opening and closing and arranged in parallel in the circumferential direction near the outer periphery of a dispersion feeder 5; and a volume detection sensor 51 that detects the volume of objects to be weighed in a straight feeder 6. When the volume detection sensor 51 detects that the volume of the objects to be weighed in the straight feeder 6 is greater than the set value, the shutter mechanism 34 corresponding to the straight feeder 6 is controlled to close.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a combination weigher that weighs and discharges predetermined weights of items to be weighed, such as food or confectionery. [Background technology]

[0002] As shown in Patent Document 1, for example, a commonly used combination weigher is configured in such a way that items to be weighed are dropped into the center of the device, are dispersed and transported radially by dispersion feeders, and are supplied to a number of straight feeders arranged around the dispersion feeders, the items to be weighed transported by each straight feeder are sent in small amounts to weighing hoppers via supply hoppers, a combination of the weighing values ​​of the weighing hoppers that results in a predetermined weight is calculated and selected, and the selected multiple weighing hoppers are controlled to open, thereby discharging the items to be weighed of the predetermined weight.

[0003] In such a combination weigher, if the amount of objects to be weighed transported by the linear feeders becomes excessive, the accuracy of the combination weighing decreases. Therefore, in order to prevent such problems, the combination weigher shown in Patent Document 1 is equipped with a layer thickness adjustment device that limits the layer thickness of the objects to be weighed transported by each linear feeder, in an attempt to uniform the amount of objects transported by each linear feeder. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-326023 Summary of the Invention [Problem to be solved by the invention]

[0005] The layer thickness adjustment device regulates the transport layer thickness of the objects to be weighed by restricting the height of the objects that pass under the lower end of the layer thickness regulating plate, so it works effectively when the objects to be weighed are easily broken down. However, when the objects to be weighed are easily tangled or stuck together, such as boiled noodles or pasta, and tend to form clumps, the objects cannot pass smoothly under the layer thickness regulating plate and are easily blocked and form clumps.

[0006] The present invention has been made with attention to these points in mind, and aims to provide a combination weigher that can uniformly transport objects to be weighed, which tend to become tangled or stick together and form clumps, using a group of straight feeders, and can perform highly accurate combination weighing. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention is configured as follows.

[0008] (1) The combination weigher according to the present invention is configured so that objects to be weighed, which are supplied to a dispersion feeder, are dispersed and conveyed to a group of linear feeders arranged radially around the dispersion feeder, and the objects to be weighed conveyed by each linear feeder are sent to a weighing hopper via a supply hopper, A plurality of shutter mechanisms that can be opened and closed are arranged in parallel in the circumferential direction near the outer periphery of the dispersion feeder, a volume detection sensor for detecting the volume of the objects to be weighed in the linear feeder; When the volume detection sensor detects that the volume of the objects to be weighed in the linear feeder is greater than a set value, the shutter mechanism corresponding to the linear feeder is controlled to close.

[0009] With this configuration, normally, all shutter mechanisms are in an open state, and the objects to be weighed on the dispersion feeders can move freely outward, but when the volume detection sensor detects that the volume of the objects to be weighed in a certain straight feeder is greater than a set value, the shutter mechanism corresponding to that straight feeder is closed, restricting the supply of objects to the straight feeder.

[0010] In this way, by temporarily restricting the supply of subsequent objects to be weighed in a straight feeder where the objects to be weighed are bulky, it is possible to prevent a large amount of objects to be weighed from being continuously supplied to the straight feeder and forming large lumps, and it is possible to prevent an excessive amount of objects to be weighed that is unsuitable for combination weighing from being sent to the supply hopper.

[0011] (2) In a preferred embodiment of the present invention, One shutter mechanism is provided for each pair of adjacent linear feeders.

[0012] According to this configuration, the number of shutter mechanisms can be reduced to half the number of linear feeder groups, which is effective in reducing costs.

[0013] (3) In another embodiment of the present invention, The volume detection sensor is provided corresponding to one of two adjacent linear feeders.

[0014] According to this configuration, the number of volume detection sensors can be reduced to half the number of linear feeders, which is effective in reducing costs.

[0015] (4) In yet another embodiment of the present invention, The shutter mechanism and the volume detection sensor are provided for each of all the linear feeders.

[0016] This configuration makes it possible to more precisely address uneven distribution of conveyance volumes for each linear feeder, which is more effective in improving weighing accuracy.

[0017] (5) In yet another embodiment of the present invention, The shutter mechanism is made up of a shutter opening / closing drive mechanism and a shutter body that is detachably attached to the shutter mechanism.

[0018] With this configuration, cleaning, inspection, and maintenance of the shutter body can be easily performed.

[0019] (6) In yet another embodiment of the present invention, The shutter body is made up of a shutter base body that is detachably connected to the shutter opening / closing drive mechanism, and a shutter operating portion that is supported on the shutter base body in a height-adjustable and detachable manner.

[0020] With this configuration, the shutter action part that comes into contact with the object to be weighed can be made of a suitable material depending on the properties of the object to be weighed, and by adjusting the height of the shutter action part relative to the shutter base, it can be closed at an appropriate height relative to the conveying surface of the dispersion feeder.

[0021] Furthermore, worn shutter operating parts can be easily replaced.

[0022] (7) In yet another embodiment of the present invention, When the shutter mechanism is closed at a predetermined number of locations, the supply of the objects to be weighed to the dispersion feeder is temporarily stopped.

[0023] With this configuration, if there are an increasing number of linear feeders carrying bulky objects and the shutter mechanisms are closed in many places, it is determined that there are more objects than necessary in the dispersion feeder, and the supply of objects is temporarily stopped. This prevents an increase in the number of linear feeders carrying bulky objects. [Effects of the Invention]

[0024] In this way, according to the present invention, it is possible to provide a combination weigher that can uniformly transport objects to be weighed, which tend to become tangled or stick together and form clumps, using a group of straight feeders, thereby enabling highly accurate combination weighing. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a vertical cross-sectional view showing a schematic configuration of a combination weigher according to an embodiment of the present invention. [Figure 2] FIG. 2 is a vertical cross-sectional view of a main part of the combination weigher of FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 10 is a vertical cross-sectional side view showing the shutter mechanism in the process of being disassembled. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. 10 is a schematic longitudinal sectional front view showing a main part of a combination weigher according to another embodiment of the present invention in an exploded view. [Figure 10] FIG. 10 is a vertical cross-sectional side view showing another embodiment of the shutter mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0026] FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a combination weigher according to one embodiment of the present invention.

[0027] The combination weigher of this embodiment is configured to weigh and discharge predetermined weights of items to be weighed that tend to tangle or stick together and form clumps, such as boiled noodles or pasta, and is installed on the upper floor F of a frame assembled like a tower that workers can climb up and down.The weighed items of a predetermined weight are discharged below the center of the device and then fed into a packaging device (not shown) installed on the floor below for bagging, and is used in packaging lines, etc.

[0028] A hollow base 1 with a large opening in the center from top to bottom is installed on the frame floor F, and a hollow center base 2 is supported above the center of the base 1 via multiple legs 3.

[0029] A supply funnel 4 is provided above the center of the center base 2 to collect the objects to be weighed dropped and discharged from a supply conveyor (not shown), and a dispersion feeder 5 is provided to distribute the objects to be weighed collected by the supply funnel 4 circumferentially and send them outward.

[0030] The dispersion feeder 5 is configured with a rotation dispersion specification in which the objects to be weighed from the supply funnel 4 are placed on a top cone 5a that is driven to rotate around a vertical axis p, and the objects are dispersed and transported radially by the weight of the objects to be weighed and centrifugal force.

[0031] Around the dispersion feeder 5, a number of linear feeders 6 (16 in this example) are arranged radially, which place the dispersed and transported objects to be weighed on vibration-driven troughs 6a and transport them in a straight line outward.

[0032] The outer wall of the center base 2 is equipped with a number of supply hoppers 7 (16 in this example) that temporarily store and discharge the objects to be weighed transported by each straight feeder 6, and a number of weighing hoppers 8 that receive the objects to be weighed discharged from each supply hopper 7, measure their weight, and discharge a fixed amount.

[0033] Below the group of weighing hoppers 8, there is provided a collecting chute 9 which guides the objects to be weighed of a predetermined weight discharged from a selected number of weighing hoppers 8 downward toward the center of the device, and at the center below the group of collecting chutes 9, there is provided a collecting funnel 10 which collects the objects to be weighed which flow down along the collecting chute 9 toward the center of the device.

[0034] As shown in Fig. 2, a motor 11 for driving the dispersion feeder is provided inside the center base body 2. The motor 11 is installed in the form of a vertical shaft, and a revolving drive shaft 12 that is rotationally driven by the motor 11 extends upward and protrudes from the central upper surface of the center base body 2. The top cone 5a of the dispersion feeder 5 is detachably connected to the upper end of this revolving drive shaft 12, so that the top cone 5a is revolved around the vertical axis p.

[0035] Inside the center base 2, a number of electromagnetically driven linear vibration mechanisms 13 are arranged to surround the motor 11. The vibration heads 13a of these linear vibration mechanisms 13 protrude from the upper surface of the center base 2, and the troughs 6a of the linear feeder 6 are detachably linked to these vibration heads 13a, so that each trough 6a is vibrated inward and outward at a predetermined amplitude and frequency.

[0036] A number of hopper drive units 14 are attached to the outer peripheral wall of the center base 2, and a supply hopper 7 and a weighing hopper 8 are detachably attached to the top and bottom of the outer part of each hopper drive unit 14, respectively.

[0037] Although the detailed structure is not shown, each of the hoppers 7 and 8 is detachably linked to a gate drive mechanism of a hopper drive unit 14, so that the opening and closing of the gates is controlled.

[0038] The weight of the entire weighing hopper 8 is applied to a load sensor incorporated in the hopper drive unit 14, and the weight value of the objects to be weighed stored in the weighing hopper 8 is measured. The basic configuration of the combination weigher is as described above, and the well-known combination weighing and discharge are carried out as follows.

[0039] That is, first, the linear feeder 6 is driven and controlled in response to the operation of the corresponding supply hopper 7, and a small amount of the objects to be weighed, approximately a fraction of the target predetermined weight, is fed into the empty supply hopper 7 and temporarily stored therein.

[0040] A supply hopper 7 is controlled to open when the corresponding weighing hopper 8 becomes empty, and the reserved objects to be weighed are discharged to the weighing hopper 8. Each weighing hopper 8 measures the weight of the objects to be weighed supplied, and a combination that results in a predetermined weight value is calculated from the group of weight values ​​of each weighing hopper 8, and multiple weighing hoppers 8 to be discharged are selected. When a discharge request is made from a downstream device such as a packaging device, the selected multiple weighing hoppers 8 are controlled to open, and the objects to be weighed of the predetermined weight are discharged toward the collecting chute 9.

[0041] The above configuration is basically the same as that of conventional combination weighers, but in the present invention, the following configuration is provided to enable objects to be weighed that tend to become tangled or stick together and form clumps to be weighed with high accuracy and then discharged.

[0042] The top cone 5a of the dispersion feeder 5 is formed in a two-stage tapered cone shape, and multiple (3 to 4) stirring rods 21 are attached in a cantilevered radial pattern close to the upper surface of the lower tapered section. The objects to be weighed are dropped from above the center and placed on the rotating top cone 5a, and while being stirred by the stirring rods 21, they are dispersed circumferentially by their own weight and centrifugal force and transported outward.

[0043] Above the straight feeders 6 arranged in parallel in the circumferential direction, a flow-down guide plate 22 having a mountain-shaped vertical cross section as seen from the front is fixedly arranged across the boundary between adjacent troughs 6a, and a loosening member 23 is arranged along the top of this flow-down guide plate 22 so as to be rotatable around an axis q extending inward and outward.

[0044] The loosening member 23 is configured as a thin blade shaft elongated inwards and outwards with four blades arranged radially, and the objects to be weighed sent from the dispersion feeder 5 to the boundary between the adjacent troughs 6a are loosened by the rotating loosening member 23 and sent to the straight feeder 6.

[0045] 2, 7 and 8 show the drive structure of the dispersion feeder 5 and the loosening member 23.

[0046] That is, gear cases 24 are attached to the inside of the peripheral wall of the center base body 2 in correspondence with the respective loosening members 23 .

[0047] Each gear case 24 is provided with a vertically oriented input shaft 25, an outwardly oriented output shaft 26, and a pair of bevel gears 27, 28 that mesh and interlock with each other.

[0048] An input pulley 29 attached to the input shaft 25 of each gear case 24 and a drive pulley 30 provided at the middle portion of the revolving drive shaft 12 are connected together by a belt.

[0049] That is, the input pulleys 29 are divided into two groups, and the eight input pulleys 29 in one group are wound around and linked to the drive pulley 30 via an upper transmission belt 31, while the eight input pulleys 29 in the other group are wound around and linked to the drive pulley 30 via a lower transmission belt 32.

[0050] In addition, the inner ends of the loosening members 23 are concentrically connected to the output shaft 25 of each gear case 24, and as the swivel drive shaft 12 rotates, the top cone 5a of the dispersion feeder 5 is driven to rotate, and all of the loosening members 23 are driven to rotate in the same direction.

[0051] A ring frame 33 is fixedly disposed above the dispersion feeder 5, and this ring frame 33 is equipped with a shutter mechanism 34 for controlling the delivery of the objects to be weighed from the dispersion feeder 5 to the linear feeder 6.

[0052] One shutter mechanism 34 is provided for each two adjacent linear feeders 6, and in this embodiment equipped with 16 linear feeders 6, eight shutter mechanisms 34 are installed facing each other near the outer periphery of the top cone 5a.

[0053] As shown in Figures 3 to 6, the shutter mechanism 34 is composed of an air cylinder 35 as a shutter drive mechanism that is connected and fixed vertically to the ring frame 33, a movable bracket 36 connected to the lower end of a piston rod 35a that extends and retracts from the underside of the air cylinder 35, and a shutter main body 37 that is detachably supported on the movable bracket 36.

[0054] A pair of guide shafts 38 extend upward from the lower edge of the movable bracket 36 and are slidably inserted and supported in the casing of the air cylinder 35, so that the lifting bracket 36 moves up and down while maintaining a constant posture as the piston rod 35a extends and retracts.

[0055] The side plates at the left and right ends of the movable bracket 36 are formed with engagement recesses 40 and step portions 41 at the top and bottom for attaching the shutter body, while the shutter body 37 has a pair of upper and lower connecting rods 42, 43 supported horizontally via support fittings 44. By inserting the upper connecting rod 42 into the engagement recess 40 and engaging the lower connecting rod 43 with the step portion 41, the shutter body 37 is supported on the movable bracket 36 in a predetermined vertical position.

[0056] In addition, the lower end of the movable bracket 36 is provided with a catcher 46 that elastically engages with a hook 45 provided at the lower end of the support bracket 44, preventing the shutter body 37, which is engaged and supported at two points above and below the movable bracket 36, from floating up and falling off.

[0057] The shutter body 37 is composed of a shutter base 37a made of a metal plate that is integrally connected to the support bracket 44, and a shutter action part 37b made of a rubber sheet or rubber plate that is detachably connected to the shutter base 37a and can be adjusted in position up and down using a long hole adjustment structure.

[0058] In this way, by constructing the shutter action part 37b as a separate part from the shutter base 37a, the position of the lower end of the shutter when the shutter main body 37 is lowered to the closed position can be changed and adjusted as desired depending on the properties of the object to be weighed, and worn shutter action part 37b can be easily replaced.

[0059] When cleaning the shutter mechanism 34 or replacing a worn shutter action part 37b, the catcher 46 is levered to release it from the hook 45, and then the shutter body can be swung up and removed from the lifting bracket 36 as shown in Figure 6.

[0060] In addition, a ring frame 48 is installed near the outer end of the loosening member 23 and is connected and fixed to the center base 2 via a support frame 47, and the outer end of the loosening member 23 is rotatably supported by a bearing bracket 49 attached to this ring frame 48.

[0061] Support columns 50 are erected at appropriate positions on the ring frame 48, and these support columns 50 are equipped with volume detection sensors 51 that detect the volume of the objects to be weighed near the end of the trough 6a in the linear feeder 6. The volume detection sensor 51 is configured to irradiate a laser beam toward the end of the conveying surface in the trough 6a and measure the volume of the conveyed objects from the reflected light.

[0062] The combination weigher according to the embodiment of the present invention is configured as described above, and like known combination weighers of this type, it selects multiple weighing hoppers 8 that will have a predetermined weight through combination calculations, and controls the opening of the selected weighing hoppers 8 to send the objects to be weighed of the predetermined weight to the collecting funnel 10. However, if an excessive amount of objects to be weighed is sent from the dispersion feeder 5 to the straight feeder 6, there is a risk of a decrease in weighing accuracy. To prevent this, the supply of objects to be weighed from the dispersion feeder 5 to the straight feeder 6 is controlled as follows.

[0063] In other words, normally, the shutter bodies 37 of all shutter mechanisms 34 are in an open position where they have been raised and retracted, and the objects to be weighed on the top cone 5a can be freely moved outward, but when the volume detection sensor 51 detects that the volume of the objects to be weighed near the end of a certain straight feeder 6 is greater than the set value, the shutter body 37 of the shutter mechanism 34 corresponding to this straight feeder 6 is controlled to descend to a closed position close to the top surface of the top cone 5a, restricting the objects to be weighed from the dispersion feeder 5.

[0064] This temporarily restricts the supply of subsequent objects to be weighed in the linear feeder 6 when the objects to be weighed have become bulky, thereby preventing a large number of objects from being continuously supplied to the linear feeder 6 and forming a large mass on the trough, and preventing an excessive amount of objects unsuitable for combination weighing from being sent to the supply hopper 7.

[0065] In the straight feeder 6 in which the supply of subsequent weighed objects is restricted, the volume on the trough gradually decreases due to continued vibration transport, and when the volume detection sensor 51 detects that the volume has reached a return setting value that is lower than the setting value for shutter closure control, the shutter body 37 of the shutter mechanism 34 is controlled to rise and return to its original open position, restoring the normal supply state in which transport from the dispersion feeder 5 is possible.

[0066] Furthermore, if the shutter mechanism 34 is closed in multiple locations (for example, three locations), it is determined that the amount of objects to be weighed in the dispersion feeder 5 is excessive, the supply conveyor, which is the upper device of the dispersion feeder 5, is controlled to stop, the supply of objects to be weighed to the dispersion feeder 5 is temporarily suspended, and when the number of locations where the shutter mechanism 34 is closed decreases, the supply of objects to be weighed to the dispersion feeder 5 is resumed.

[0067] Other Embodiments of the Invention The present invention can also be implemented in the following forms.

[0068] (1) As shown in FIG. 9, a bulk detection sensor 51 may be installed corresponding to each linear feeder 6, and a shutter mechanism 34 may be provided individually for each linear feeder 6, thereby enabling more precise supply control.

[0069] (2) As for the shutter opening and closing mode of the shutter mechanism 34, as shown in FIG. 10, the movable bracket 34 can also be swung inward and outward using a rotary shutter opening and closing drive mechanism 52 such as an electric motor.

[0070] (3) The rotating type dispersion feeder 5 can be configured to rotate the top cone 5a in a constant direction at all times, or to reverse the direction of rotation at set intervals, depending on the properties of the objects to be weighed.

[0071] (4) The dispersion feeder 5 may be designed so that the top cone 5a is vibrated. [Explanation of symbols]

[0072] 5. Dispersion feeder 5a Top Cone 6 Straight feeder 7 Supply hopper 8 Weighing hopper 34 Shutter mechanism 35 Air cylinder (shutter opening / closing drive mechanism) 37 Shutter body 37a shutter base 37b Shutter action part 51 Volume detection sensor

Claims

1. A combination weigher is configured so that objects to be weighed, which are supplied to a dispersion feeder, are dispersed and conveyed to a group of linear feeders arranged radially around the dispersion feeder, and the objects to be weighed conveyed by each linear feeder are sent to a weighing hopper via a supply hopper, A plurality of shutter mechanisms that can be opened and closed are arranged in parallel in the circumferential direction near the outer periphery of the dispersion feeder, a volume detection sensor for detecting the volume of the objects to be weighed in the linear feeder; When the volume detection sensor detects that the volume of the objects to be weighed in the linear feeder is greater than a set value, the shutter mechanism corresponding to the linear feeder is controlled to close. A combination weigher characterized by:

2. One shutter mechanism is provided for two adjacent linear feeders. The combination weigher according to claim 1 .

3. The volume detection sensor is provided corresponding to one of two adjacent linear feeders. The combination weigher according to claim 2.

4. The shutter mechanism and the volume detection sensor are provided for each of all the linear feeders. The combination weigher according to claim 1 .

5. The shutter mechanism is composed of a shutter opening / closing drive mechanism and a shutter body attached to the shutter mechanism so as to be engageable with and detachable from the shutter body. The combination weigher according to claim 1 .

6. The shutter body is composed of a shutter base body detachably connected to the shutter opening / closing drive mechanism, and a shutter operating part detachably supported on the shutter base body in a height adjustable manner. The combination weigher according to claim 5.

7. When the shutter mechanism is closed at a predetermined number of locations, the supply of the objects to be weighed to the dispersion feeder is temporarily stopped. The combination weigher according to any one of claims 1 to 5.

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