JP2006225152A - Carrying device and combined weighing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispense with a mechanism such as a sensor for detecting a vibration state, by determining an excitation pulse train on the basis of these values, a supplement impulse for compensating for a damping quantity of a momentum of a vibrating part by respective excitation pulses, and a growth impulse by the respective excitation pulses. <P>SOLUTION: A control part of a combinational weighing device is provided with an excitation pulse setting part 141 and a control pulse generating part 143. The excitation pulse setting part 141 is provided with a growth quantity arithmetic operation part 145, a damping quantity arithmetic operation part 146 and an excitation pulse arithmetic operation part 147. The growth impulse for growing vibration (increasing amplitude) up to target amplitude, is determined with respective excitation pulses by the growth quantity arithmetic operation part 145. The supplement impulse for compensating for the damping quantity is determined with respective excitation pulses by the damping quantity arithmetic operation part 146. The excitation pulse arithmetic operation part 147 determines the excitation pulse train by determining an impulse imparted by the respective excitation pulses by adding the growth impulse and the supplement impulse. The control pulse generating part 143 also controls an impression of voltage on an electromagnet in response to the determined excitation pulse train. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for conveying an article by vibration. More specifically, the present invention relates to a technique for controlling conveyance vibration.

  In a weighing device or the like, for example, an electromagnetic feeder (conveying device) is provided to transfer the supplied article to a weighing hopper or the like. Each electromagnetic feeder includes, for example, a trough attached to the base member via a pair of front and rear spring bodies, an electromagnet installed on the base member, and an energization control unit that energizes the electromagnet intermittently during a normal conveyance period. Have. In addition, the electromagnetic feeder generates an electromagnetic force intermittently with an electromagnet, displaces the trough in one direction while bending the spring body at the time of the occurrence, and by the elastic restoring force of the spring body at the time of non-occurrence. By displacing the trough to the other side, the trough is vibrated to transfer the article on the trough in a predetermined direction.

  For example, in combination weighing devices equipped with multiple electromagnetic feeders of this type, supply of articles from the electromagnetic feeder to the weighing hopper can be improved by increasing weighing accuracy, device efficiency, and combination calculation efficiency. There is a need to improve the accuracy of the quantity. That is, it is necessary to control the conveyance vibration of the electromagnetic feeder with high accuracy.

JP 09-2335016 A

  However, when the electromagnetic feeder is driven as intended, how to suppress the transient vibration generated before and after the trough is in steady vibration (steady state), that is, how short the transient period is, and There was a problem of how the behavior during that time was within an allowable range. In particular, at the start of vibration, there is a problem that the vibration state must be quickly brought to a steady state.

  As a method for solving this problem, for example, it is conceivable to overexcit the electromagnet of the electromagnetic feeder. Overexcitation is a technique that generates a strong electromagnetic force and vibrates by applying a voltage (overvoltage) greater than the voltage (steady voltage) applied to the electromagnet in a steady state when trough vibration is started. is there. Accordingly, the period during which the trough reaches the target amplitude is shortened, and the voltage applied when the trough reaches the steady state is set to the steady voltage, so that the trough vibration can be quickly stabilized in the steady state.

  However, even when overexcitation is performed, there is a problem of how much overvoltage should be applied for which period, or at what frequency is appropriate. That is, there is a problem of how to determine each parameter. For example, when an overshoot (a phenomenon in which the amplitude becomes larger than the target amplitude) occurs due to excessive overexcitation, it not only delays the arrival of the steady state, but also may destroy the electromagnetic feeder. On the other hand, if the overexcitation is too small, the period until the steady state is reached is lengthened, and the effect of overexcitation is reduced. Further, if the frequency at the time of applying the voltage is inappropriate, the electromagnetic force attenuates the vibration (undershoot), which causes a delay in reaching the steady state.

  Conventionally, a method has been proposed in which a vibration sensor is provided to determine the voltage to be applied by feedback control while detecting the amplitude of the transition period, but problems such as erroneous control due to time lag and complicated device configuration There is.

  The present invention has been made in view of the above problems, and an object of the present invention is to appropriately control the vibration of the transport device.

  In order to solve the above-described problems, the invention of claim 1 is a transport device that transports an article by vibrating a vibrating portion by intermittent energization of an electromagnet based on application of an excitation pulse train, and based on a target amplitude. An excitation pulse setting means for presetting the excitation pulse train; and an energization control means for controlling the energization of the electromagnet based on the excitation pulse train set by the excitation pulse setting means, The excitation pulse setting means includes a growth amount calculation means for obtaining a growth impulse for growing the amplitude of the vibration part by each excitation pulse constituting the excitation pulse train, and a vibration amount setting means for the vibration part by each excitation pulse. Attenuation amount calculating means for obtaining a complementary impulse for supplementing the amount of attenuation of the momentum, the growth impulse obtained by the growth amount calculating means, and the amount obtained by the attenuation amount calculating means Based on the complete impulse, characterized by comprising a vibration pulse calculating means obtains the excitation pulse train.

  The invention according to claim 2 is the transfer apparatus according to the invention according to claim 1, wherein the growth impulse calculating means calculates a maximum momentum when the vibrating portion vibrates with a target amplitude, and the maximum momentum. Is distributed to each excitation pulse according to a predetermined pattern to calculate the growth impulse.

  Further, the invention of claim 3 is the transport apparatus according to the invention of claim 1 or 2, wherein the attenuation amount calculating means calculates the amount of attenuation of the momentum of the vibrating section for each period of the excitation pulse train. The complementary impulse is obtained by calculation.

  The invention according to claim 4 is the transport apparatus according to any one of claims 1 to 2, wherein the excitation pulse calculating means has a value obtained by adding the growth impulse and the complementary impulse. The excitation pulse train is calculated so that the excitation impulse product given to the vibration part by each excitation pulse is obtained.

  The invention according to claim 5 is the transport apparatus according to any one of claims 1 to 4, wherein the excitation pulse calculating means sets the frequency of the excitation pulse train to a resonance frequency unique to the vibrating section. It is characterized by that.

  A sixth aspect of the present invention is the transport apparatus according to any one of the first to fifth aspects of the present invention, wherein a vibration suppression pulse for setting a vibration suppression pulse train for stopping the vibration of the vibration section after the end of the conveyance period is provided. The vibration suppression pulse setting means further sets a timing for applying the vibration suppression pulse based on the vibration waveform of the vibration unit, and the energization control means is configured to set the timing at the end of the conveyance period. The energization of the electromagnet is controlled by the vibration suppression pulse set by the vibration suppression pulse setting means.

  The invention of claim 7 is a combination weighing device that weighs and combines articles, and a plurality of conveying apparatuses that convey the article by vibrating the vibrating portion by intermittent energization of an electromagnet based on application of an excitation pulse train. And a plurality of weighing means for weighing the articles conveyed by the plurality of conveying devices, respectively, and the conveying device sets the excitation pulse train in advance based on a target amplitude, and An energization control unit that controls energization of the electromagnet based on the excitation pulse sequence set by the excitation pulse setting unit, and the excitation pulse setting unit includes each excitation pulse sequence that constitutes the excitation pulse sequence. A growth amount calculating means for obtaining a growth impulse for growing the amplitude of the vibration part by the vibration pulse, and an amount of attenuation of the momentum of the vibration part are compensated by each excitation pulse. The excitation pulse train is calculated based on the attenuation amount calculating means for obtaining the complementary impulse, the growth impulse obtained by the growth amount calculating means, and the complementary impulse obtained by the attenuation amount calculating means. And an excitation pulse calculating means for obtaining the above.

  According to the first to seventh aspects of the present invention, a growth impulse for growing the amplitude of the vibration part is obtained by each excitation pulse constituting the excitation pulse train, and the amount of momentum attenuation of the vibration part is determined by each excitation pulse. A mechanism such as a sensor for detecting a vibration state is not required by obtaining a complementary impulse product for compensating for and obtaining an excitation pulse train based on these values.

  According to the fifth aspect of the present invention, by setting the frequency of the excitation pulse train to a resonance frequency unique to the vibration unit, an appropriate frequency can be easily determined for the excitation pulse train.

  According to the sixth aspect of the present invention, by setting a damping pulse train for stopping the vibration of the vibration unit at the end of the conveyance period based on the vibration waveform of the vibration unit, The vibration of the vibration part can be stopped.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

<1. First Embodiment>
FIG. 1 is a side view showing a schematic configuration of a combination weighing device 2 provided with an electromagnetic feeder 1 according to a first embodiment of the present invention. FIG. 2 is a side view specifically showing the configuration of the electromagnetic feeder 1. Referring to FIG. 1, a combination weighing device 2 is installed in the center of a machine base 3 via a vibration exciter 4 and disperses objects to be weighed dropped from an upper cylindrical charging chute 5 to the surroundings. A plurality of troughs 8 are arranged radially around the table 6 and a plurality of vibration exciters 7 around the table 6 so as to convey an object to be weighed, and are positioned below the front ends of the plurality of troughs 8, respectively. A plurality of pool hoppers 9 arranged radially and a plurality of weighing hoppers 10 arranged below each of the plurality of pool hoppers 9 are provided. Here, the electromagnetic feeder 1 includes a vibration exciter 7 and a trough 8.

  A plurality of gate opening / closing devices 11 for controlling the opening / closing of the gates 9 a of the pool hoppers 9 and the gates 10 a of the weighing hoppers 10 are disposed inside the machine base 3. The gate opening / closing device 11 is driven by a motor (not shown), and when receiving an object discharge command, the gate opening / closing device 11 discharges the object to be weighed in the weighing hopper 10 into the collecting chute 12 by a driving means (not shown) and becomes empty. The weighing hopper 10 is operated so that the objects to be weighed in the pool hopper 9 are put into the weighing hopper 10. In addition, a weight detector (not shown) is connected to the weighing hopper 10 in the machine base 3 to measure the weight of the object to be weighed in the weighing hopper 10.

  Referring to FIG. 2, the vibration exciter 7 included in the electromagnetic feeder 1 includes a base member 22 installed on the machine base 3 via a plurality of coil springs 21, and an electromagnet installed on the upper surface of the base member 22. 23 and a pair of leaf springs 25 attached in parallel in a backward inclined posture by bolts 24 on the front side (right side of the drawing) and the rear side (left side of the drawing) of the base member 22. However, the pair of leaf springs 25 are not necessarily attached in parallel. A bracket 8 a of the trough 8 is fixed to each upper part of both the leaf springs 25 by bolts 26. A magnetic body 27 is attached to the surface of the bracket 8a that faces the magnetic force generation surface 23a of the electromagnet 23. The electromagnet 23 is intermittently energized by a feeder control device 30 described later.

  When the electromagnet 23 is energized, an electromagnetic force (attraction force) acts between the magnetic force generation surface 23a and the magnetic body 27. As a result, the front and rear leaf springs 25 are bent, and at the same time, the trough 8 is It will be displaced backward (left side of the drawing) while sinking slightly. That is, the trough 8 to which the leaf spring 25 is fixed and functions as an elastic member is displaced rearward. On the other hand, when the energization to the electromagnet 23 is stopped, the electromagnetic force (attraction force) between the magnetic force generation surface 23 a and the magnetic body 27 disappears, and the trough 8 is slightly moved upward by the elastic restoring force of the leaf spring 25. It will be displaced forward (right side of the drawing) while floating.

  Therefore, when the electromagnet 23 is energized intermittently, an electromagnetic force is intermittently generated, thereby causing the trough 8 to vibrate in the front-rear direction. At this time, the electromagnetic force generated in the electromagnet 23 is determined by the voltage value when the feeder controller 30 is energized. That is, the relational expression between the voltage E and the electromagnetic force F is determined in advance.

  When the trough 8 vibrates, the articles (the objects to be weighed and the objects to be transported) on the trough 8 are transferred to the pool hopper 9 shown in FIG. Further, when the predetermined article conveyance period ends, the transfer of the article from the electromagnetic feeder 1 to the pool hopper 9 is stopped by stopping the vibration of the trough 8.

  As described above, in the combination weighing device 2, in order to improve the accuracy of the amount of articles supplied from the electromagnetic feeder 1 to the pool hopper 9, the period during which articles are conveyed (that is, the period during which the trough 8 is vibrating, It is important to accurately control the length of the "article conveyance period" and the intensity of vibration (mainly the amplitude of the trough 8) between them.

  FIG. 3 is a bus wiring diagram showing a connection between the control unit 13 and another configuration. Although not shown in FIG. 1, the combination weighing device 2 further includes an operation unit 16 and a display 17 that displays data to the operator.

  The control unit 13 is mainly composed of a CPU 14 and a storage device 15, and has a function as a general computer. The CPU 14 processes various data according to a program stored in the storage device 15 to generate a control signal and the like for controlling other configurations of the combination weighing device 2. The CPU 14 controls each component by transmitting such a control signal via the bus wiring. The storage device 15 includes a RAM used as a temporary working area of the CPU 14, a read-only ROM, a hard disk device, and the like, and stores programs, data input from the operation unit 16, and the like.

  The operation unit 16 includes a keyboard 16a and a mouse 16b, and is used to input instructions from the operator. When the operator operates the operation unit 16, various parameters, programs, instructions, and the like are input to the combination weighing device 2. As the operation unit 16, various buttons, a touch panel, and the like may be employed.

  FIG. 4 is a block diagram showing a functional configuration realized mainly by the CPU 14 operating according to a program. In FIG. 4, the excitation pulse setting unit 141, the vibration suppression pulse setting unit 142, and the control pulse generation unit 143 are functional configurations mainly realized by the CPU 14. The CPU 14 implements these functional configurations by operating according to a program, but all or part of them may be implemented by hardware using a dedicated circuit.

  The parameter data 100 illustrated in FIG. 4 is data such as setting data and initial values given to the combination weighing device 2 in advance, and is mainly input from the operation unit 16 and stored in the storage device 15. The parameter data 100 includes the mass m of the vibration part, the resonance frequency f0 of the vibration part, the damping ratio ζ of the vibration part, the target amplitude r0, and the like. These values can be obtained in advance by experiments, for example.

  The excitation pulse setting unit 141 sets an excitation pulse train Pf for vibrating the trough 8 of the electromagnetic feeder 1 while referring to the parameter data 100 and transmits the set to the control pulse generation unit 143.

  FIG. 5 is a block diagram showing details of the excitation pulse setting unit 141. The excitation pulse setting unit 141 includes a growth amount calculation unit 145, an attenuation amount calculation unit 146, and an excitation pulse calculation unit 147.

  The growth amount calculation unit 145 calculates the maximum momentum Mmax in the steady vibration state. The maximum momentum Mmax is the momentum at time nT (T: vibration period) when the trough 8 is oscillating at the target amplitude r0 and the speed is maximum.

  In the vibrating object, the displacement when the speed is maximum is “0”. That is, the contribution of the applied electromagnetic force to the potential energy is “0”. Therefore, it is not necessary to consider the leaf spring 25 at this time.

Further, the growth amount calculation unit 145 determines an impulse (hereinafter referred to as “growth impulse product GW _n ”) to be used for growing vibration by each excitation pulse, and the attenuation amount calculation unit 146 and the excitation pulse calculation unit. 147.

The attenuation amount calculation unit 146 calculates an attenuation amount (hereinafter referred to as “attenuation amount D _n ”) for one period of the excitation pulse train, and a value of impulse corresponding thereto (hereinafter referred to as “complementary impulse product DW _n ”). Is transmitted to the excitation pulse calculation unit 147.

The excitation pulse calculation unit 147 obtains an impulse W _n to be given by the excitation pulse based on the growth impulse GW _n and the complementary impulse DW _n . Further, each excitation pulse is obtained based on the obtained impulse W _n , thereby obtaining the excitation pulse train Pf.

  The excitation pulse setting unit 141 outputs the excitation pulse train Pf obtained by the excitation pulse calculation unit 147 to the control pulse generation unit 143.

  Returning to FIG. 4, the vibration suppression pulse setting unit 142 calculates a vibration suppression pulse train Ps for stopping the conveyance of the article by the electromagnetic feeder 1 and outputs it to the control pulse generation unit 143.

  The control pulse generator 143 generates and outputs a control pulse train Pc corresponding to the excitation pulse train Pf and the vibration suppression pulse train Ps. The control pulse train Pc output from the control pulse generator 143 is input to the switching element 32. During the period when the control pulse is input, the switching element 32 becomes conductive and the DC power supply 31 is energized to the electromagnet 23. Thereby, the vibration of the trough 8 is controlled.

  That is, the control pulse generator 143 and the switching element 32 function as energization control means for controlling energization from the DC power supply 31 to the electromagnet 23 by the excitation pulse train Pf or the vibration suppression pulse train Ps.

  The above is the description of the function and configuration of the combination weighing device 2 in the present embodiment. In the above description, it is described that one control unit 13 is provided in the combination weighing device 2, but more specifically, the function of the control unit 13 is realized for each electromagnetic feeder 1. Each electromagnetic feeder 1 may be provided with a functional configuration equivalent to that of the control unit 13.

  Next, the theory for controlling the vibration of the trough 8 will be described with respect to the combination weighing device 2 including the electromagnetic feeder 1 according to the present embodiment.

  FIG. 6 is a diagram illustrating an example of an excitation pulse train. In such an excitation pulse train, the voltage values of the pulse voltages applied to the electromagnet are equal. That is, overexcitation is not performed in the excitation pulse train shown in FIG. FIG. 7 is a diagram showing the displacement of the trough 8 by the excitation pulse train shown in FIG. In the displacement, the initial position of the trough 8 when the electromagnet 23 is not energized and the leaf spring 25 is not deformed is “0”. Also, the time when the first excitation pulse is applied is set to “0”.

  Hereinafter, the period from the start of vibration by applying an excitation voltage to the steady vibration state is the start-up period, and the period from the steady vibration state to the stop of application of the excitation voltage is the steady conveyance period A period from when the application of the excitation voltage is stopped to when the vibration stops is defined as a convergence period.

  In the electromagnetic feeder 1, the article is conveyed while the trough 8 is vibrating. That is, the article is conveyed during a period (article conveyance period) in which the activation period, the steady conveyance period, and the convergence period are totaled.

  As described above, during the steady conveyance period, the trough 8 is in a steady vibration state in which the amplitude of the trough 8 is constant. Since the conveyance amount of the electromagnetic feeder 1 depends on the amplitude of the trough 8, the conveyance amount of articles in the regular conveyance period (the supply amount to the pool hopper 9) is almost proportional to time and can be controlled with relatively high accuracy. it can.

  However, since the amplitude of the trough 8 is not stable during the start-up period and the convergence period, the supply amount of articles is relatively difficult to control. In the example shown in FIG. 6, in the start-up period, the amplitude of the trough 8 increases only gradually even though the steady voltage is applied, so that the actual supply amount is smaller than the intended supply amount. Become. Further, even if the application of the steady voltage is stopped, the vibration does not stop immediately, and the article is transported by continuing the vibration of the trough 8 during the convergence period, increasing the supply amount.

  For this reason, in the electromagnetic feeder 1, it is important to shorten the startup period and the convergence period as much as possible.

  First, a method for shortening the activation period will be described.

  Since the vibration amplitude in the steady vibration state (steady conveyance period) is the target amplitude r0, the displacement X (t) in the steady vibration state can be expressed by Equation 1 using the resonance frequency f0.

  Therefore, the speed v (t) in the steady vibration state can be expressed by Equation 2.

  Since the maximum speed Vmax in the steady state is the speed at time nT, the maximum speed Vmax can be obtained from Equation 3.

  When the maximum speed Vmax is obtained, the maximum momentum Mmax is obtained by Equation 4.

  The electromagnetic feeder 1 gives an impulse GW corresponding to the maximum momentum Mmax by the electromagnet 23 in order to cause the stationary trough 8 to vibrate at a target amplitude r0. Various methods can be considered for giving the impulse GW. For example, it may be given by one excitation pulse.

In the electromagnetic feeder 1 in the present embodiment, an impulse GW corresponding to the maximum momentum Mmax is given by a plurality of excitation pulses. That is, when the growth impulse GW _n given by the n-th excitation pulse is used, it is expressed by Equation 5.

Further, in the electromagnetic feeder 1 in the present embodiment, a technique is adopted in which the electromagnetic force Fmax is first applied to vibrate strongly, and then the amplitude is gradually increased. That is, when the electromagnetic force that gives the growth impulse GW _n is the electromagnetic force GF _n , and the pulse width of the excitation pulse is the pulse width tp, the growth impulse GW _n is given as shown in Equation 6.

  Note that “A” in Equation 6 is a dimensionless parameter for adjusting the rise of the amplitude, and can be arbitrarily given. Therefore, if the impulse GW is given by n number of excitation pulses, Fmax can be obtained from Equation 4 to Equation 6 from Equation 7.

That is, when the target amplitude r0 is given, the growth amount calculation unit 145 calculates Formula 7 to obtain Fmax, and supplies the growth product GW _n shown in Formula 6 to the attenuation amount calculation unit 146 and the excitation pulse calculation unit 147. introduce.

The trough 8 once started to vibrate by the first vibration pulse is attenuated until the next vibration pulse is applied (for one period). In the electromagnetic feeder 1, the amount of vibration attenuation is compensated by an excitation pulse. That is, since it is necessary to supplement the attenuation amount for each cycle of the excitation pulse train, the attenuation amount calculation unit 146 needs to obtain the attenuation amount D _n for each cycle.

Here, consider a case where vibration is naturally damped. When the vibration with the amplitude r _n−1 is attenuated, the amplitude r _n after one cycle can be approximated by the equation 8 using the attenuation ratio ζ.

Further, since the frequency by the damping can be approximated as unchanged, the maximum speed V _n in the vibration amplitude r _n is determined by the number 3 in the same manner as in Equation 9.

Accordingly, the momentum attenuation amount D _n during one period from a certain vibration state (from the time when the (n−1) th excitation pulse is applied to the time when the nth excitation pulse is applied) is expressed by the following equation (10). .

  Further, by substituting Equation 8 into Equation 10, Equation 11 is obtained.

Here, using the momentum M _n at the time when the n-th excitation pulse is applied, the vibration amplitude r _n is expressed as follows.

  Substituting Equation 12 into Equation 11 yields Equation 13.

Note that the trough 8 is stationary until the first excitation pulse is applied, and the amount of attenuation does not need to be considered when the first excitation pulse is applied, so “D ₁ = 0”.

Therefore, in order to compensate for the attenuation amount D _n , the complementary impulse product DW _n that must be given from the electromagnet 23 by the n-th excitation pulse is obtained by Equation 14.

Here, we put the electromagnetic force F _n given by the n-th excitation pulse, the impulse given by the n-th excitation pulse (F _n · tp), and n-1 th excitation pulse is given The momentum M _n can be expressed as Equation 15 using the attenuation amount D _n until the n-th excitation pulse is applied.

As will be described in detail later, the electromagnetic force F _n given by the excitation pulse is obtained by adding the growing electromagnetic force GF _n for growing the vibration and the complementary electromagnetic force DF _n for compensating for the attenuation.

  Therefore, Equation 15 is transformed into Equation 16.

Further, since the attenuation amount D _n corresponds to the complementary impulse product DW _n as shown in the equation 14, it can be expressed by the equation 17 using the complementary electromagnetic force DF _n .

  Therefore, substituting equation 17 into equation 16 yields equation 18.

However, the electromagnetic force F ₁ given by the first excitation pulse is “GF ₁ = F ₁ = Fmax” because the attenuation electromagnetic force for compensating for the attenuation is “0”.

When Expression 18 is substituted into Expression 14, the complementary impulse DW _n is expressed by Expression 19.

  Further, when Expression 6 is substituted into Expression 19, Expression 20 is obtained.

However, “DW ₁ = 0”.

In this manner, the attenuation amount calculation unit 146 obtains the growth impulse GW _n as an input from the growth amount calculation unit 145 and stores it. Further, based on the growth impulse GW _n−1 stored up to the previous time and the damping ratio ζ included in the parameter data 100, the complementary impulse DW _n is obtained by calculating Equation 20; This is transmitted to the excitation pulse calculation unit 147.

Based on the growth impulse GW _n obtained from the growth amount calculation unit 145 and the complementary impulse DW _n obtained from the attenuation amount calculation unit 146, the excitation pulse calculation unit 147 applies the excitation pulse given by the nth excitation pulse. Obtain the vibration product W _n . That is, the excitation impulse product W _n is obtained by Equation 21.

Further, the electromagnetic force F _n to be generated in the electromagnet 23 by each excitation pulse is obtained from the excitation force product W _{n by} Equation 22.

  Since the electromagnetic force F is an electromagnetic force generated in the electromagnet 23 by applying the voltage E, the relational expression F (E) between the voltage E and the electromagnetic force F is obtained in advance as a characteristic of the electromagnet 23. be able to.

  FIG. 8 is a diagram illustrating an example of the excitation pulse train Pf in the present embodiment. That is, in the electromagnetic feeder 1 in the present embodiment, the excitation pulse calculation unit 147 obtains the excitation pulse train Pf as shown in FIG. The voltage E given by the excitation pulse train Pf shown in FIG.

  Note that “B” in Equation 23 is a dimensionless parameter for adjusting the rise of the amplitude, and can be arbitrarily given according to the value of “A” in Equation 6.

  Since the voltage Emax applied by the first excitation pulse generates an electromagnetic force generated by the first excitation pulse, the voltage Emax can be obtained by Expression 24.

In addition, in the steady vibration state (target amplitude r0), the growth electromagnetic force GF _n is already “0”, and therefore the voltage Emin can be obtained by Expression 25.

  The excitation pulse calculation unit 147 can also obtain in advance the excitation pulse to be given according to the voltage E (the relational expression between the excitation pulse and the voltage E is known). That is, if the necessary electromagnetic force F is obtained from Equation 22, an excitation pulse for causing the electromagnet 23 to generate the electromagnetic force F can be obtained.

  In this way, the excitation pulse setting unit 141 calculates the excitation pulse train Pf by obtaining each excitation pulse by the excitation pulse calculation unit 147 and transmits the excitation pulse train Pf to the control pulse generation unit 143.

  FIG. 9 is a diagram showing the displacement of the trough 8 excited by the excitation pulse train shown in FIG. In the example shown in FIG. 7, the activation period is about 9 seconds (not shown). As is clear from FIG. 9, the electromagnetic feeder 1 has reached a steady vibration state in about 0.1 seconds. The startup period has been shortened.

As described above, the electromagnetic feeder 1 according to the present embodiment includes the growth amount calculation unit 145 for obtaining the growth impulse GW _n for growing the amplitude of the trough 8 for each excitation pulse constituting the excitation pulse train Pf. , The amount of momentum attenuation D _n of the trough 8 is obtained, and for each excitation pulse, an attenuation amount calculating unit 146 for obtaining a complementary impulse DW _n for supplementing the amount of attenuation D _n , the growth impulse GW _n and the complementary force By providing the excitation pulse calculation unit 147 for determining the excitation pulse train Pf based on the product DW _n , an appropriate excitation pulse train Pf can be obtained by calculation, and therefore the vibration state (especially amplitude) is detected. No sensor is required for this purpose.

  In addition, it is possible to easily predict and control the vibration as compared with the conventional case where the input from the sensor is obtained and the next excitation pulse is determined, so that the occurrence of overshoot in overexcitation is suppressed. be able to.

  Next, a method for shortening the convergence period will be described.

  In the electromagnetic feeder 1 in this Embodiment, the theory in a starting period is employ | adopted also in a convergence period. That is, the trough 8 oscillating with the momentum M is given a stop impulse SW in the opposite direction and stopped.

  Here, various methods can be considered for giving the stop impulse product SW as in the case of the excitation pulse train Pf. In the present embodiment, a method of applying the stop impulse product SW by the vibration suppression pulse train Ps composed of one vibration suppression pulse is adopted, but it may of course be provided by a plurality of vibration suppression pulses.

  First, the damping pulse setting unit 142 determines the time to give the damping pulse train Ps according to the vibration waveform of the trough 8. In the present embodiment, immediately after the end of the regular conveyance period, the vibration suppression pulse train Ps is given at the timing when the vibration displacement of the trough 8 becomes “0”. In other words, the vibration velocity v (t) of the trough 8 may be given at the maximum timing in the direction away from the electromagnet 23. Specifically, since it may be given after a half cycle has elapsed since the last excitation pulse was given, assuming that the nth excitation pulse is the last excitation pulse, the time when the damping pulse train Ps is given t is obtained by Equation 26.

  Since the vibration is also attenuated during the half cycle, if this attenuation is set to “D”, the attenuation D can be approximated by Equation 27 from Equation 11. However, the attenuation amount D may be obtained by calculation instead of an approximate expression.

  Therefore, the momentum M at the time of giving the vibration suppression pulse train Ps is obtained by the following equation (28).

  When the electromagnetic force that generates the stop impulse product SW is set as the stop electromagnetic force SF, the stop impulse product SW is expressed by Equation 29 using the pulse width ts of the damping pulse.

  Since the absolute value of the momentum M and the value of the stop impulse product SW are equal, Equation 30 is obtained from Equation 28 and Equation 29.

  If the stop electromagnetic force SF to be generated by the vibration suppression pulse train Ps is obtained, the vibration suppression pulse train Ps is obtained in the same manner as the vibration pulse train Pf.

  As described above, in the electromagnetic feeder 1 according to the present embodiment, the vibration suppression pulse train Ps for stopping the vibration of the trough 8 is given by the vibration suppression pulse setting unit 142. The convergence period is shortened.

As described above, the electromagnetic feeder 1 according to the present embodiment obtains the growth impulse GW _n for growing the trough 8 amplitude by each excitation pulse constituting the excitation pulse train Pf, and the trough 8 A vibration sensor is obtained by obtaining a complementary impulse DW _n for supplementing the damping amount D _n of the momentum with each excitation pulse, and obtaining an excitation pulse train based on the growth impulse GW _n and the complementary impulse DW _n. Such a configuration becomes unnecessary. Therefore, the apparatus configuration is simplified and the cost is reduced.

  Further, by controlling vibration (open loop control) using the excitation pulse train Pf obtained by calculation, it is possible to suppress the occurrence of overshoot or the like in overexcitation compared to trial and error control. Further, erroneous control due to time lag can be suppressed.

  In addition, after the last excitation pulse is applied, the vibration suppression pulse train Ps is set at the most appropriate timing such as the timing when the vibration displacement X becomes “0” or the timing when the vibration velocity v (t) becomes maximum. Can be given. Therefore, the vibration of the trough 8 can be quickly and effectively stopped, and the cycle time of intermittent movement can be improved.

  Moreover, according to the electromagnetic feeder 1 which concerns on this Embodiment, the damping pulse train Ps which consists of only one damping pulse with respect to one conveyance period is set. Therefore, a negative effect when a plurality of vibration suppression pulses are set for one transport period (for example, the application timing of the second and subsequent vibration suppression pulses is shifted and vibration is applied instead of vibration suppression). The occurrence of adverse effects) can be avoided.

  Further, according to the combination weighing device 2 including the electromagnetic feeder 1 according to the present embodiment, a weighing device in which the conveyance amount of articles from the electromagnetic feeder 1 to the pool hopper 9 is accurately controlled can be obtained.

  Moreover, since the vibration of the trough 8 can be started and stopped quickly, the supply time of the articles can be shortened and the weighing cycle time can be improved.

  Furthermore, since the vibration of the trough 8 can be quickly stopped at the end of the transport period, articles are not continuously supplied to the pool hopper 9 after the end of the transport period. Therefore, when the pool hopper 9 is closed after the end of the conveyance period, it is possible to prevent the articles supplied from the electromagnetic feeder 1 from being clogged in the pool hopper 9 (so-called biting of articles into the pool hopper).

<2. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made.

  For example, the timing at which the vibration displacement X of the trough 8 becomes “0” is obtained by calculation using mathematical formulas. However, when there is a margin in the data storage capacity of the electromagnetic feeder 1, it may be obtained by table value control. That is, a table describing in advance the timing at which the vibration displacement X of the trough 8 becomes “0” by changing the amplitude of the vibration of the trough 8, the frequency and pulse width of the excitation pulse train Pf, and the like in advance for each condition. Create it. Then, the feeder control device 30 holds the data of the table, and according to the currently given conditions, the timing at which the displacement X becomes “0” immediately after the conveyance period ends is determined from the table, and the control is performed at that timing. An oscillation pulse train Ps is applied. Even with this method, the same effect as described above can be obtained.

Also, when conveying actually article may attenuation D _n of electromagnetic feeder 1 by friction forces between the article and the trough 8 increases, not obtained as target amplitude r0 is intended There is a thing. Greater complement impulse DW _n in order to obtain the target amplitude r0 is required. Further, when the complementary impulse DW _n becomes large, the growth impulse GW _n becomes insufficient, and the rise of the amplitude may be deteriorated. This phenomenon remarkably occurs when driving at the resonance frequency.

Therefore, the combination of the article and the trough 8 in the preliminary experiment or the like, and the previously obtained amount of increase in attenuation D _n, by recalculating the excitation pulse train Pf using this value, complementary impulse DWn that insufficient It becomes possible to replenish. Further, it is possible also ensuring growth impulse GW _n. As a result, even if the article is on the trough 8, the target amplitude can be maintained, and the rising speed of the amplitude can be recovered.

Further, as described in the above embodiment, various methods can be considered for applying the excitation pulse train Pf. For example, the initial excitation pulse may use the maximum voltage. FIG. 10 is a diagram illustrating an example of such an excitation pulse train Pf. FIG. 11 is a diagram showing an example of the amplitude of the trough 8 when controlled by the excitation pulse train Pf shown in FIG. By providing such an excitation pulse train Pf, a steady state can be achieved earlier than in the case of applying the excitation pulse train Pf as shown in FIG. At this time, the number of necessary excitation pulses (excitation pulses for setting a large value) can be calculated from the target amplitude r0, the growth impulse GW _n , and the complementary impulse DW _n .

Further, the initial excitation pulse may be set to a large value for the pulse width tp. FIG. 12 is a diagram showing an example of such an excitation pulse train Pf. FIG. 13 is a diagram showing an example of the amplitude of the trough 8 when controlled by the excitation pulse train Pf shown in FIG. Even when such an excitation pulse train Pf is applied, the steady state can be achieved earlier than in the case of applying the excitation pulse train Pf as shown in FIG. 6 (FIG. 7). In this case, the number of The required excitation pulse (excitation pulse to set a large tp), the target amplitude r0, growth impulse GW _n, can be calculated from the complementary impulse DW _n.

It is a side view which shows schematic structure of the combination weighing | measuring apparatus provided with the electromagnetic feeder which concerns on embodiment of this invention. It is a side view which shows the structure of an electromagnetic feeder concretely. It is a bus wiring diagram which shows the connection of a control part and another structure. It is a block diagram which shows the function structure mainly implement | achieved when CPU operate | moves according to a program. It is a block diagram which shows the detail of an excitation pulse setting part. It is a figure which shows the example of an excitation pulse train. It is a figure which illustrates the displacement of the trough by the voltage shown in FIG. 6 being applied. It is a figure which shows the example of the excitation pulse train in this Embodiment. It is a figure which illustrates the displacement of the trough vibrated by the vibration pulse train shown in FIG. It is a figure which shows the example of the excitation pulse train in a modification. It is a figure which illustrates the displacement of the trough vibrated by the vibration pulse train shown in FIG. It is a figure which shows the example of the excitation pulse train in a modification. It is a figure which illustrates the displacement of the trough vibrated by the vibration pulse train shown in FIG.

Explanation of symbols

1 Electromagnetic feeder (conveyor)
10 Weighing hopper 100 Parameter data 13 Control unit 14 CPU
141 Excitation Pulse Setting Unit 142 Damping Pulse Setting Unit 143 Control Pulse Generation Unit 145 Growth Amount Calculation Unit 146 Attenuation Amount Calculation Unit 147 Excitation Pulse Calculation Unit 15 Storage Device 2 Combination Weighing Device 23 Electromagnet 25 Plate Spring 30 Feeder Control Device 31 DC power source 32 switching element 8 trough ζ damping ratio DW _n complementary impulse D, D _n attenuation GW _n growth impulse Mmax maximum momentum Pc control pulse train Pf excitation pulse train Ps damping pulse train SW stop impulse product W _n excitation impulse product f0 resonance frequency m mass r0 target amplitude tp, ts pulse width

Claims (7)

A conveying device that conveys an article by vibrating a vibrating portion by intermittent energization of an electromagnet based on application of an excitation pulse train,
An excitation pulse setting means for presetting the excitation pulse train based on a target amplitude;
Energization control means for controlling energization to the electromagnet based on the excitation pulse train set by the excitation pulse setting means;
With
The excitation pulse setting means includes
A growth amount calculating means for obtaining a growth impulse for growing the amplitude of the vibration part by each excitation pulse constituting the excitation pulse train;
Attenuation amount calculating means for obtaining a complementary impulse for supplementing the amount of attenuation of the momentum of the vibrating part by each excitation pulse;
Based on the growth impulse obtained by the growth amount calculating means and the complementary impulse obtained by the attenuation amount calculating means, an excitation pulse calculating means for obtaining the excitation pulse train;
A conveying device comprising: It is a conveying apparatus of Claim 1, Comprising:
The growth impulse calculating means includes:
The transport is characterized in that the growth moment is calculated by calculating a maximum momentum when the vibrating portion vibrates at a target amplitude and distributing the maximum momentum to each excitation pulse according to a predetermined pattern. apparatus. It is a conveying apparatus of Claim 1 or 2, Comprising:
The said attenuation amount calculating means calculates | requires the said complementary impulse by calculating the amount of attenuation of the momentum of the said vibration part for every period of the said excitation pulse train, The conveying apparatus characterized by the above-mentioned. It is a conveyance apparatus in any one of Claim 1 thru | or 3, Comprising:
The excitation pulse calculating means includes
The conveyance device that calculates the excitation pulse train so that a value obtained by adding the growth impulse and the complementary impulse is an excitation impulse product that is given to the vibration unit by each excitation pulse. . It is a conveying apparatus in any one of Claims 1 thru | or 4, Comprising:
The conveying apparatus characterized in that the excitation pulse calculating means sets the frequency of the excitation pulse train to a resonance frequency unique to the vibrating section. It is a conveying apparatus in any one of Claim 1 thru | or 5, Comprising:
Further comprising a vibration suppression pulse setting means for setting a vibration suppression pulse train for stopping the vibration of the vibration part after the conveyance period ends,
The vibration suppression pulse setting means sets the timing for applying the vibration suppression pulse based on the vibration waveform of the vibration unit,
The conveyance device, wherein the energization control unit controls energization to the electromagnet at the end of the conveyance period by the vibration suppression pulse set by the vibration suppression pulse setting unit. A combination weighing device for weighing and combining articles,
A plurality of conveying devices for conveying an article by vibrating the vibrating portion by intermittent energization of an electromagnet based on application of an excitation pulse train;
A plurality of weighing means for weighing each of the articles conveyed by the plurality of conveying devices;
With
The transfer device is
An excitation pulse setting means for presetting the excitation pulse train based on a target amplitude;
Energization control means for controlling energization to the electromagnet based on the excitation pulse train set by the excitation pulse setting means;
With
The excitation pulse setting means includes
A growth amount calculating means for obtaining a growth impulse for growing the amplitude of the vibration part by each excitation pulse constituting the excitation pulse train;
Attenuation amount calculating means for obtaining a complementary impulse for supplementing the amount of attenuation of the momentum of the vibrating part by each excitation pulse;
Based on the growth impulse obtained by the growth amount calculating means and the complementary impulse obtained by the attenuation amount calculating means, an excitation pulse calculating means for obtaining the excitation pulse train;
A combination weighing device comprising:

Images