JP4323826B2 - Electromagnetic vibratory feeder and combination weighing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combination weighing device for weighing an article having a variation in individual weight such as confectionery, fruit, and vegetable, and an electromagnetic vibration feeder thereof.
[0002]
[Prior art]
The combination weighing device is a device for weighing various articles such as confectionery, fruits, vegetables, and the like that vary in individual weights by a predetermined amount. In such a combination weighing device, an electromagnetic vibration feeder that vibrates using on / off of excitation of an electromagnet is provided in order to sequentially supply articles supplied from upstream to a weighing unit while dispersing them. . By controlling the amplitude and the number of times of vibration (vibration time) of the electromagnetic vibration type feeder, the input of articles into the weighing unit is adjusted. Such a combination weighing device and an electromagnetic vibration feeder are already known (for example, refer to Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-131129
[Problems to be solved by the invention]
In the conventional combination weighing device and the electromagnetic vibration feeder, for example, as disclosed in Patent Document 1, the intermittently excited electromagnet intermittently displaces the magnetic body provided in the movable part of the electromagnetic vibration feeder. By attracting, the movable part of the electromagnetic vibration type feeder including the magnetic body is vibrated.
[0005]
However, in this aspect, there is a problem that a sufficient amplitude cannot be given to the movable part, or the response of the vibration of the movable part to the excitation timing is poor.
[0006]
The present invention has been made in view of such a problem, and an object thereof is to provide an electromagnetic vibration type feeder having a movable part having a large amplitude and good response characteristics, and a combination weighing device including the same.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention of claim 1 is an electromagnetic vibration type feeder that generates a magnetic force from an electromagnet by an exciting means, and vibrates a movable part arranged facing the electromagnet by the magnetic force, A feeder base; a plurality of leaf springs attached to the feeder base; a connecting member that connects upper end portions of the plurality of leaf springs to form a part of the movable portion; and a permanent attached to the connecting member A magnet, the magnetic pole of the permanent magnet and the electromagnet face each other vertically, the electromagnet includes a plurality of magnetic cores, a plurality of the permanent magnets corresponding to the plurality of magnetic cores, and the plurality of magnets By disposing the core and the plurality of permanent magnets on a single loop, the magnetic force lines of the magnetic force generated when the magnetic core and the permanent magnet are attracted are made into a closed loop.
[0009]
The invention of claim 2 is the electromagnetic vibratory feeder according to claim 1, wherein said excitation means is capable reversing the direction of the magnetic force generating.
[0010]
The invention of claim 3 is the electromagnetic vibratory feeder according to claim 2, wherein the excitation means by using an AC power source, and performs the direction of reversal of the magnetic force.
[0013]
According to a fourth aspect of the present invention, the electromagnetic vibration type feeder according to any one of the first to third aspects and the electromagnetic vibration type feeder are disposed below and supplied from the electromagnetic vibration type feeder. A plurality of weighing units including weighing means for weighing the articles, and performs combination weighing based on the measured values in each of the weighing units.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
<Outline of combination weighing device>
FIG. 1 is a diagram schematically showing a combination weighing device 1 according to an embodiment of the present invention. The combination weighing device 1 mainly includes a dispersion feeder 2, a radiation feeder 3, a pool hopper 4, a weighing hopper 6, a weight detector 7, and a collective discharge chute 9. Among them, except for the dispersion feeder 2 and the collective discharge chute 9, the same number of each is isotropically disposed below the dispersion feeder 2 so that each component is substantially continuous one by one.
[0015]
As shown in FIG. 1, when an article to be weighed is conveyed as indicated by an arrow AR1 from the conveying conveyor 100 of the supply device provided upstream, it sequentially falls as indicated by an arrow AR2 to the central portion of the dispersion feeder 2. . A plurality of radiation feeders 3 are provided on the periphery of the dispersion feeder 2. Both the dispersion feeder 2 and the radiation feeder 3 are electromagnetic vibration type feeders. The feeder 2 and the dispersion feeder 2 are vibrated by driving a vibration device (not shown), and the articles on the dispersion feeder 2 are distributed and supplied to each radiation feeder 3 as indicated by an arrow AR3.
[0016]
Since the trough 37 of the radiating feeder 3 is vibrated as will be described later, the article supplied to the radiating feeder 3 is supplied to the pool hopper 4 provided downstream by this vibration.
[0017]
A gate 5 is provided below the pool hopper 4. By keeping the gate 5 closed, the articles supplied from the radiation feeder 3 can be temporarily stored in the pool hopper 4.
[0018]
A weighing hopper 6 is provided downstream of the pool hopper 4. The weighing hopper 6 is accompanied by a weight detector 7 for detecting the weight of the article supplied into the weighing hopper 6, and a gate 8 is provided at the lower part.
[0019]
In each weighing hopper 6, the weight value detected by the weight detector 7 for the articles in the weighing hopper 6 becomes the target of combination weighing. That is, an article corresponding to a combination closest to a desired weight value is selected and discharged from the sum obtained by combining several weight values. When an article in a certain weighing hopper 6 is selected as a combination selection target, the corresponding gate 8 is opened, and the article is discharged to a collective discharge chute 9 for receiving the discharged article provided below the gate 8. The empty weighing hopper 6 is supplied with the next article from the upper pool hopper 4 via the gate 5 and is weighed.
[0020]
<Structure of radiation feeder>
Next, the structure of the radiation feeder 3 according to the present embodiment will be described. FIG. 2 is a diagram schematically showing the structure of the radiation feeder 3. All of the radiation feeders 3 provided in the combination weighing device 1 according to the present embodiment have the same structure.
[0021]
As shown in FIG. 2, the radiation feeder 3 includes a feeder base 33 installed on the support portion 31 via a plurality of coil springs 32, a plurality of leaf springs 34 attached to the feeder base 33, and these A connecting member 35 for connecting the upper end of the leaf spring 34, a trough 37 supported on the connecting member 35 and configured to be swingable (vibrable), and a magnetic material such as iron on the feeder base 33. A plurality (two in the illustrated example) of electromagnets 38 (38L, 38R) installed via the holding member 40 and the connecting member 35 are attached via a holding member 41 made of a magnetic material such as iron (see FIG. 2) permanent magnets 39 (39L, 39R) are mainly provided. Note that the magnetic core 38a and the holding member 40 may be provided as an integral unit. Here, the connecting member 35, the trough 37, and the permanent magnet 39 are hereinafter referred to as a movable part M.
[0022]
FIG. 3 is a partially enlarged view of the radiation feeder 3 in FIG. As shown in FIG. 3, each electromagnet 38 is formed by winding a conducting wire 38b around a magnetic core 38a. For the magnetic core 38a, a magnetic material such as iron is used, for example. The conducting wire 38b is connected to the excitation control unit 36 (FIG. 2). An AC power supply AC is also connected to the excitation control unit 36. The AC power source AC is preferably a commercial power source having a commercial frequency. The excitation control unit 36 is provided to control the electromagnetic force generated in the electromagnet 38 by controlling the voltage applied to the conducting wire 38b or the energization current of the electromagnet 38.
[0023]
Further, the electromagnet 38 and the permanent magnet 39 are arranged so that the end of the magnetic core 38a that becomes a magnetic pole when the electromagnet 38 is excited and the magnetic pole of the permanent magnet 39 are close to each other. Here, the two permanent magnets 39 are arranged such that different magnetic poles face the electromagnet 38. Further, the two electromagnets 38 are arranged so that different magnetic poles always face the permanent magnet 39 when excited. In FIG. 3, two permanent magnets 39 are fixed so that the lower part of the permanent magnet 39L is the S pole, the upper part is the N pole, the lower part of the permanent magnet 39R is the N pole, and the upper part is the S pole. Correspondingly, in each of the electromagnets 38L and 38R, the conductive wire 38b is wired so that when one of the upper parts is an N pole during energization, the other upper part is an S pole. Each time the direction of application of the AC voltage is reversed, the direction of the current is reversed and the magnetic pole of the electromagnet 38 is reversed, so that a magnetic flux in the direction opposite to that before the reversal is generated between the electromagnet 38 and the permanent magnet 39. Will do. The natural frequency of the leaf spring 34 is adjusted to a value close to the frequency of the AC power supply AC.
[0024]
The electromagnet 38 is excited when an AC voltage generated by the AC power supply AC is controlled and applied by the excitation controller 36. The magnetic poles (N pole, S pole) are inverted according to the AC voltage applied as a sine wave. FIG. 3 shows a state in which the upper part of the electromagnet 38L facing the N pole of the permanent magnet 39L is energized to the S pole and the upper part of the electromagnet 38R facing the S pole of the permanent magnet 39R is turned to the N pole. . In this state, an attractive force acts between both magnetic poles. Further, as described above, since the end portions of the electromagnet 38 and the permanent magnet 39 are fixed by the holding members 40 and 41 which are magnetic bodies, the magnetic flux generated when a voltage is applied to the electromagnet is a single closed loop. Become LP. Thereby, since magnetic flux is effectively utilized in the case of attraction | suction, a bigger attraction | suction force can be obtained.
[0025]
Such an attractive force and a repulsive force act in the vertical direction between the permanent magnet 39 and the electromagnet 38, but the movable portion M is also restrained by the leaf spring 34 via the connecting member 35, and the plate Since the elastic force from the spring 34 is also received, the entire movable portion M vibrates in the ab direction as indicated by an arrow AR7. Due to this vibration, the articles supplied from the dispersion feeder 2 to the radiation feeder 3 as indicated by an arrow AR8 are supplied to the pool hopper 4 as indicated by an arrow AR9 while being conveyed.
[0026]
<Vibration control in radiation feeder>
Next, vibration control in the radiation feeder 3 according to the present embodiment will be described. 4A and 4B are diagrams for explaining this, in which FIG. 4A shows the AC voltage V generated in the AC power supply AC, FIG. 4B shows the current I flowing through the conductor 38b of the electromagnet 38, and FIG. 4C shows the current I. Shows the attractive force F generated in the electromagnet 38. In (c), the case where the attractive force F acts in the direction in which the electromagnet 38 attracts the permanent magnet 39 is positive. The horizontal axis is time. FIG. 5 is a diagram for explaining half-wave control in a conventional radiation feeder for comparison with FIG. (A)-(c) has shown the element corresponding to FIG. 4, respectively.
[0027]
Assume that the AC power supply AC generates an AC voltage V as a sine wave with a period T, as indicated by a dotted line in FIGS. 4A and 5A. In the conventional radiation feeder, as indicated by a solid line in FIG. 5A, the voltage V is applied (energized) for a certain time ΔT until the voltage V reaches the zero value from the value V1 every period T. The excitation control unit 36 according to the present embodiment applies the voltage V for a certain time ΔT until the voltage V reaches the zero value from the absolute value V1 (voltage value V1 or −V1) every T / 2 period. It is different.
[0028]
When the voltage V is applied to the electromagnet 38, the current I flows through the conducting wire 38b as shown in FIG. When the current I is not flowing, a constant force F = F0 is applied between the permanent magnet 39 and the electromagnet 38 between the permanent magnet 39 and the magnetic core 39 as shown in FIG. Acts as a suction force. The movable portion M is stopped in a state where the balance between the suction force and the elastic force of the leaf spring 34 is maintained. When the current I flows, the attraction force F is alternately increased or decreased by the electromagnetic force generated accordingly. In FIG. 4C, the suction forces F when increased and decreased are F1 and F2, respectively. The movable part M vibrates by the increase / decrease of the suction force and the change of the elastic force of the leaf spring 34. FIG. 6A shows a change in the displacement Z of the movable part M in a steady state. In the Z axis, the direction in which the movable part M is separated from the electromagnet 38 is positive. In a steady state, when the maximum displacement in the direction in which the movable part M moves away from the electromagnet 38 is Z1, and the maximum displacement in the direction in which the movable part M approaches the electromagnet 38 is Z2, the movable part M moves away from the electromagnet 38 and reaches Z = Z1. Thus, the elastic force of the leaf spring 34 is maximized downward. At this time, the suction force F is minimized, but when the direction of the movable part M is reversed, the suction force F starts to increase. When the movable part M reaches Z = Z2, the elastic force of the leaf spring 34 becomes maximum upward. At this time, the suction force F is maximized, but when the direction of the movable portion M is reversed, the suction force F starts to decrease. In the steady state, this operation is repeated as the current I is turned on / off. That is, in the steady state, the suction force F changes so as to further promote the vibration of the movable part M.
[0029]
In the conventional radiating feeder, no attracting force is generated when it is not energized, and even when it is energized, the polarity of the applied voltage V and current I is constant. As shown in (c), the suction force F3 was only generated at regular intervals. FIG. 6B is a diagram showing a change in the displacement Z of the movable part in the steady state. When the movable part M moves away from the electromagnet 38, the electromagnetic force does not act, so the maximum displacement Z3 is ) Was smaller than the maximum displacement Z1.
[0030]
In the radiation feeder 3 according to the present embodiment, since the electromagnetic force acts to change the attractive force F even when the movable part M tries to approach the electromagnet 38, the response to the applied voltage V has been improved compared to the conventional case. It can be said that it has also improved. Further, the maximum displacement difference in the radiation feeder 3 according to the present embodiment is Z1 + Z2, whereas the maximum displacement difference Z3 + Z2 of the conventional radiation feeder, and Z1> Z3, so that the applied voltage V is the same. Even if it exists, the direction of the radiation feeder 3 which concerns on this Embodiment will obtain a big vibration. This means that the radiation feeder 3 according to the present embodiment can obtain the same level of vibration as the conventional one even with a small voltage V.
[0031]
As described above, since the radiation feeder 3 according to the present embodiment can use the change in the attractive force due to the change in the electromagnetic force that is alternately inverted to the vibration of the movable part M, the conventional radiation feeder. in comparison, improved response to the applied voltage V, it can be said that the larger the vibration amplitude is obtained. Moreover, energy consumption can be reduced. In addition, it can be said that the combination weighing device 1 according to the present embodiment is provided with the radiation feeder 3 to improve the processing capacity of the combination weighing.
[0032]
<Modification>
The arrangement relationship of the magnetic poles of the electromagnet 38 and the permanent magnet 39 is not limited to the above example. For example, as shown in FIG. 7, the two permanent magnets 39 may be arranged so that the same magnetic pole faces the electromagnet 38. In this case, in the two electromagnets 38, the magnetic poles generated according to the AC voltage are always the same type of magnetic poles. In FIG. 7, the case where all the magnetic poles of the electromagnet 38 are N poles is shown. When the magnetic poles are arranged in this way, the magnetic flux does not form one closed loop between the magnetic poles at the time of attraction or repulsion, but as in the case described above, the attraction force and the repulsion force are By utilizing this, the vibration characteristics of the radiation feeder 3 can be improved.
[0033]
Further, in the radiation feeder 3 of FIG. 2, a plurality of electromagnets 38 and a plurality of permanent magnets 39 are provided, but the number of each may be singular. FIG. 8 is a diagram showing a configuration example when only one permanent magnet 39 is provided. In this case, since the closed loop LP of the magnetic flux passes through the permanent magnet 39, the holding member 41 is not necessarily required.
[0034]
It is also possible to use a direct current power supply instead of the alternating current power supply. In this case, for example, the excitation control unit 36 is provided with a polarity inverting circuit that can constantly reverse the polarity when the conducting wire 38b of the electromagnet 38 is energized.
[0035]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the magnetic force generated by the permanent magnet can be used, the attractive force generated by the magnetic force of the electromagnet alone can be used efficiently. Therefore, the amplitude of the feeder can be made larger than before, and the actual vibration response of the feeder corresponding to the control by energizing the conducting wire can be improved.
[0036]
Further, according to the first aspect of the present invention, the magnetic flux generated by the permanent magnet can be efficiently used by aligning the directions of the magnetic fluxes with each other. Vibration response is further improved.
In particular, according to the first aspect of the present invention, the feeder can be vibrated even if the current value of the current to be energized is smaller than that of the conventional one, so that energy consumption can be reduced or even the smaller electromagnet is vibrated. The volumetric efficiency is improved.
According to the invention of claim 1, since the generated magnetic flux can be used effectively, the energy utilization rate can be improved and vibration can be performed with less supply energy. Or even if it is a case where the energy of the same magnitude | size is supplied, a suction | attraction force and a repulsive force become large.
[0037]
In particular, according to the second aspect of the present invention, the increase and decrease of the attractive force caused by the change of the electromagnetic force generated between the electromagnet and the permanent magnet can be used for the vibration of the feeder, and the amplitude of the feeder can be made larger than before. Can do. Thereby, the response of the feeder can be further improved.
[0038]
In particular, according to the invention of claim 3 , since the polarity of the electromagnet can be easily reversed without providing any special means, the change of the electromagnetic force generated between the electromagnet and the permanent magnet can be used for the vibration of the feeder. Cost can be reduced.
[0041]
Further, according to the invention of claim 4 , since the article can be used for weighing earlier, the processing capacity of the combination weighing device can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a combination weighing device 1. FIG.
FIG. 2 is a diagram schematically showing the structure of the radiation feeder 3;
FIG. 3 is a partially enlarged view of the radiation feeder 3;
FIG. 4 is a diagram illustrating vibration control in the radiation feeder 3;
FIG. 5 is a diagram for explaining vibrations in a conventional radiation feeder.
FIG. 6 is a diagram showing the displacement of the movable part of the radiation feeder in a steady state.
7 is a diagram showing a modification of the arrangement of magnetic poles of an electromagnet 38 and a permanent magnet 39. FIG.
FIG. 8 is a view showing a modified example in the case where there is one permanent magnet 39;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Combination measuring device 2 Dispersing feeder 3 Radiation feeder 4 Pool hopper 6 Weighing hopper 7 Weight detector 9 Collecting discharge chute 34 Leaf spring 35 Connecting member 36 Excitation control part 37 Main part 38 (38L, 38R) Electromagnet 38a Magnetic core 38b Conductor 39 (39L, 39R) Permanent magnet 40, 41 Holding member AC AC power supply

Claims (4)

An electromagnetic vibration feeder that generates magnetic force from an electromagnet with excitation means, and vibrates a movable part arranged facing the electromagnet by the magnetic force,
Feeder base,
A plurality of leaf springs attached to the feeder base;
A connecting member that connects upper end portions of the plurality of leaf springs to form a part of the movable portion;
A permanent magnet attached to the connecting member;
With
The magnetic pole of the permanent magnet and the electromagnet are vertically opposed to each other,
The electromagnet includes a plurality of magnetic cores, and includes a plurality of the permanent magnets corresponding to the plurality of magnetic cores,
By arranging the plurality of magnetic cores and the plurality of permanent magnets on a single loop, the magnetic force lines of the magnetic force generated when the magnetic core and the permanent magnets are attracted are closed loops. Electromagnetic vibratory feeder. The electromagnetic vibration feeder according to claim 1,
An electromagnetic vibration feeder characterized in that the direction of the magnetic force generated by the exciting means can be reversed. The electromagnetic vibration feeder according to claim 2,
An electromagnetic vibration feeder, wherein the excitation means uses an AC power source to reverse the direction of the magnetic force. An electromagnetic vibration feeder according to any one of claims 1 to 3,
A weighing unit disposed below each of the electromagnetic vibration feeders and weighing an article supplied from the electromagnetic vibration feeder;
With multiple weighing units including
A combination weighing device that performs combination weighing based on a measurement value in each of the weighing units.

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