JP5410855B2 - Hopper gate opening / closing device and weighing device having the same - Google Patents

Description

  The present invention relates to a hopper gate opening / closing device that opens and closes a hopper gate provided in a hopper that accommodates articles therein, and a weighing device including the hopper gate, and particularly, a stepping motor that is used as a drive source that opens and closes the hopper gate is out of step. TECHNICAL FIELD The present invention relates to a hopper gate opening / closing device that can effectively suppress the above and a weighing device including the same.

  For example, various types of weighing devices such as combination weighers and quantitative feeding devices are known, and various configurations are adopted as weighing mechanisms, but a weighing hopper is a typical weighing mechanism. Can be mentioned. In addition, in a combination weigher or the like, a configuration including a supply hopper for supplying an object to be weighed to the weighing hopper is also widely known. These weighing hoppers, supply hoppers, etc. (collectively simply referred to as hoppers) are generally spaces in which the inside temporarily stores objects to be weighed, and the objects to be weighed are supplied to the upper side. An opening is formed, and a hopper gate is provided on the lower side so as to discharge an object to be weighed.

  Usually, a stepping motor is used to open and close the hopper gate, but this stepping motor is always accompanied by a problem of step-out. The step-out is a state in which the synchronization between the command pulse input to the stepping motor and the rotation of the stepping motor is lost, and is particularly likely to occur when the stepping motor is suddenly operated. Examples of the abrupt operation include a time when rotation starts or stops, or a time point when forward and reverse rotation is repeated within a short time.

  In particular, when the hopper gate is driven to open and close at a high speed, a high torque is required to start or stop the rotation, and therefore step-out is likely to occur. Specifically, for example, in a combination weigher having many hoppers, a plurality of hoppers are used for one combination weighing. Therefore, in order to increase the processing capacity, the hopper gate needs to be opened and closed at a high speed. There is. In order to perform the opening / closing operation of the hopper gate at high speed, the pulse interval of the command pulse is shortened as much as possible. However, when the pulse interval is shortened, the torque of the stepping motor decreases. In this case, for example, if the self-starting speed of the stepping motor becomes high, a torque corresponding to the speed cannot be obtained, so that the rotation of the stepping motor cannot follow the command pulse and a step-out occurs. When the step-out occurs, the hopper gate is not completely closed, so that an object to be weighed may leak from the weighing hopper or the supply hopper, which affects the combination weighing. Therefore, it is important to take measures against the step-out in the opening / closing mechanism of the hopper gate.

  As a technique for dealing with the problem of step-out occurring in the stepping motor that drives the hopper gate in the field of the weighing device (for convenience of explanation, simply abbreviated as “step-out problem”), for example, the applicant of the present application has disclosed Patent Document 1 and The technique disclosed in 2 is proposed. These techniques appropriately adjust the driving pattern of the stepping motor, and therefore can effectively reduce the frequency of occurrence of step-out when the hopper gate is opened and closed.

  First, in Patent Document 1, in order to effectively suppress step-out of a stepping motor that is likely to occur when a gate is opened and closed, in a control device for a combination weigher, a plurality of gate drive times for a hopper gate include at least one acceleration section and one constant speed section. The pulse interval is set to the minimum pulse interval during the constant velocity interval, and the pulse interval is larger than the minimum pulse interval and gradually decreased during the acceleration interval. A necessary series of pulse generation patterns) is calculated, and the operation of the stepping motor is controlled according to this pulse pattern. According to this configuration, it is no longer necessary to manually perform complicated and complicated work that has been performed manually by skilled workers, and even a low-skilled operator can easily perform step-out, and A pulse pattern with a short gate drive time can be set.

  In addition, the weighing device and the weighing system disclosed in Patent Document 2 are not techniques for reducing the occurrence of step-out, but a weighing in which a large number of operation patterns specified by a plurality of setting items are set. An object of the present invention is to easily prevent or correct errors and leaks in these setting items in the apparatus and the weighing system. In the weighing device and the weighing system, the control device is configured to appropriately sort the setting items corresponding to the plurality of operation patterns based on the setting items stored in the storage device and output them in a table. In particular, the storage device is preferably configured to store the setting item and the analysis item for analyzing the operation result in association with each other. Key error is included.

  The motor step-out error is determined to occur when the actual motor position has returned to the origin when it is controlled to return the motor position (angle) of the stepping motor to the origin. Error (analysis item). By associating this error with the setting item, it is possible to easily identify an operation pattern that is highly likely to have an error in the setting value of the operation parameter.

JP 2006-201099 A JP 2008-216028 A

  In any of the above-described techniques, the out-of-step problem can be appropriately dealt with, and as a result, a suitable operation of the weighing device is possible. It has been revealed by the present inventors that this is necessary.

  First, the technique disclosed in Patent Document 1 deals with step-out by idealizing the pulse pattern and the pulse interval, so that even an unskilled person can easily set an optimal pulse pattern. it can. However, the frequency of adjustment may increase or stable reproducibility may not be obtained depending on the operating conditions of the weighing device.

  That is, in order to avoid the occurrence of step-out, it is only necessary to increase the torque of the stepping motor by increasing the pulse interval of the command pulse. However, this technique is only the reverse of the conditions for speeding up the opening / closing operation of the hopper gate, so when applied to a combination weigher or the like, the opening / closing operation of the hopper gate is slowed, the measuring speed is reduced, and the tipping over occurs. Therefore, in actual operation, the command pulse generation pattern (pulse pattern) should be set as the optimal pattern in order to set the optimum value for the time (gate open / close time) from when the gate starts to close until the hopper gate opens. become. When setting the optimum pulse pattern, the pulse interval must be adjusted to be short enough to prevent step-out and to shorten the gate opening and closing time.

  However, since the time to be discharged from the hopper differs depending on the type of the object to be weighed, various conditions such as the fluidity, viscosity, temperature, etc. of the object to be weighed must be considered in setting the optimum pulse pattern. As a result, the hopper gate is opened and closed while actually changing the pulse interval, and an optimum pulse pattern is searched for while confirming the occurrence of step-out.

  As mentioned in Patent Document 1, when searching for an optimal pulse pattern according to the type of object to be weighed, a very complicated and troublesome work is required. It was necessary to optimize the pulse pattern manually. Therefore, in the technique disclosed in Patent Document 1, the above-described control is performed so that even an operator with a low skill level can easily set an optimal pulse pattern. However, since it is necessary to make adjustments by the operator according to the measurement status, if the conditions are easily changed, the frequency of adjustment increases, which is a burden on the operator. Furthermore, when the adjustment frequency increases, it is sufficient that the adjustment is performed by the same operator. However, in the situation where the operator is changed, the pulse pattern and the pulse interval may be idealized. Further, there may be a slight deviation in the reproducibility of adjustment.

  In the technique disclosed in Patent Document 2, a motor step-out error is included in a large number of operation patterns specified by a plurality of setting items. Therefore, although this technique can deal with the out-of-step problem, basically, as with the technique disclosed in Patent Document 1, since it depends on adjustment by the operator, It is not possible to sufficiently cope with an increase in adjustment frequency or a deviation in adjustment reproducibility.

  As long as stable operation is possible without changing the above-mentioned various conditions regarding the operation of the weighing device, an increase in adjustment frequency, a deviation in reproducibility of adjustment, and the like hardly affect the operation. Therefore, the technique disclosed in Patent Document 1 or 2 can be appropriately handled. However, considering the recent sophistication and diversification of demands on weighing devices, the above-mentioned problem of step-out is considered after taking into consideration the situation where the increase in the adjustment frequency and the deviation in the reproducibility of the adjustment affect the operation. It is necessary to deal with it.

  The present invention has been made to solve such a problem, and in the field of the weighing device, the hopper gate is driven by a stepping motor, and various conditions accompanying the operation of the weighing device are easily changed. Even so, an object of the present invention is to provide a technique capable of easily and effectively suppressing the influence of the step-out generated in the stepping motor.

  As a result of earnestly examining the above problems, the present inventor did not construct a closed loop system control as a stepping motor, but caused a stepping motor by constructing a closed loop system control as a whole hopper gate opening / closing device including the stepping motor. The present inventors have found that the influence of the step-out can be easily and effectively suppressed, and that the hopper gate can be smoothly opened and closed, thereby completing the present invention.

That is, a hopper gate opening and closing device according to the present invention includes a stepping motor, a hopper gate that can be freely opened and closed, a gate opening and closing mechanism that opens and closes the hopper gate under the rotational force of the stepping motor, and A position sensor that is provided on a rotating shaft of a stepping motor or a mechanism member constituting the gate opening / closing mechanism, detects a position in rotation of the rotating shaft or a position in operation of the mechanism member, and outputs a command pulse to the stepping motor. Comparing the measured value of the position change detected by the position sensor with the preset value of the position change when the motor driving circuit for driving the stepping motor and the opening / closing operation of the hopper gate, If there is a difference between these values, the stepping motor A step-out determination unit that determines that step-out has occurred, a storage unit, and a controller are provided, and the storage unit patterns the operation of the stepping motor in response to the opening / closing operation of the hopper gate. A motor drive pattern which is information for continuously changing the command pulse is stored in the controller, and the controller controls the motor drive circuit based on the motor drive pattern to drive the stepping motor, and If the step-out determination unit determines that the step-out has occurred, the motor drive pattern is reset, and the step-out determination unit performs a plurality of single opening / closing operations of the hopper gate. In each of the opening / closing steps, the occurrence of the step-out is determined by comparing the measured value of the position change with the specified value. A step determined to be performed is identified as a step-out step, and the motor drive pattern stored in the storage unit is organized as a set of step-specific command pulses set in each of the opening and closing steps, and the control The device determines which of the plurality of opening / closing steps corresponds to the step-out step, and based on the determination result, at least one of the plurality of step-by-step command pulses organized as the motor drive pattern Is configured to change .

  Conventionally, when a step-out occurs in a stepping motor, it has been dealt with by manual adjustment. In other words, the engineer determines whether or not there is a step-out by visual confirmation. When the step-out occurs, the engineer resets the conditions and then drives the stepping motor to rotate. Trial and error was repeated until it disappeared. This kind of manual adjustment takes time to adjust if the technician in charge is low, and even if the technician in charge is high, the details of the adjustment are sensitive to the personal preference and tendency of the technician. Differences occur.

  In this case, it is conceivable to check the occurrence of step-out using a position sensor and feed back this. In other words, if the rotational position of the stepping motor is detected by the position sensor and fed back to adjust the rotational position, it is possible to suppress the occurrence of step-out regardless of the manual operation. However, the stepping motor is an inexpensive system (open loop system) that does not require feedback, and can achieve high positioning accuracy and speed control. It became clear that it was not suitable for practical use only by losing the advantages of stepping motors.

  Therefore, in the present invention, the stepping motor is driven based on the motor drive pattern, and if the occurrence of the step-out is determined by the step-out determination unit, the motor drive pattern is reset. Thereby, the occurrence of the step-out detected using the position sensor can be fed back to the control of the entire operation of the hopper gate opening / closing device including the stepping motor, instead of being fed back to the rotation control of the stepping motor.

  In other words, according to the above configuration, the pulse pattern for driving the stepping motor to rotate is not grasped as a problem of the opening / closing operation of the hopper gate but not as a problem of the rotating operation of the stepping motor. Instead of resetting appropriately, the motor drive pattern that is the reference for the entire opening / closing operation is reset. The motor drive pattern is information including a pulse pattern because it is information for continuously changing the command pulse so as to pattern the operation of the stepping motor corresponding to the opening / closing operation of the hopper gate. Therefore, instead of re-setting the pulse pattern, the specific command pulse related to the step-out is found out of a plurality of command pulses included in the motor drive pattern as seen from the entire opening / closing operation of the hopper gate. Can be reset.

  Therefore, with the above-described configuration, the control for coping with the occurrence of step-out can be made more efficient, so that a quick adjustment process can be performed compared with either manual adjustment work or feedback control of the stepping motor. It becomes possible. Moreover, with the above-described configuration, various problems that occur in opening and closing of the hopper gate due to out-of-step, for example, failure to discharge the object to be weighed or delay in discharging due to the hopper gate not being fully opened, or the hopper gate is not completely closed. It can be used to control the hopper gate opening and closing device by judging leakage of the object to be weighed from the hopper body or weighing error of the object to be weighed, and stepping out due to biting of the object to be weighed into the hopper gate Can also be determined.

As a result, according to the present invention, it is possible to suppress the occurrence of step-out as compared with the case where only the stepping motor is feedback-controlled, and the adjustment time is not limited to manual adjustment because of the automatic control. Can be greatly shortened. Further, compared to manual adjustment, it is possible to prevent adjustment differences and erroneous settings by engineers. In addition, according to the above configuration, the opening / closing operation of the hopper gate is divided into a plurality of opening / closing steps, and the command pulse is changed for each opening / closing step. As a result, the motor drive pattern can be reset more efficiently and with good reproducibility.

  The hopper gate opening / closing apparatus according to the present invention further includes a timer for measuring at least an opening / closing operation time, which is a time required for one opening / closing operation of the hopper gate, in addition to the above configuration, and the storage device further includes the opening / closing device. An allowable range of operation time may be stored, and the controller may be configured to reset the motor drive pattern so that the opening / closing operation time measured by the timer is within the allowable range.

  According to the above configuration, the timer is provided, and the measurement result of the timer is used for control. Therefore, the time for opening and closing the hopper gate (gate opening and closing time) is unlimited with the resetting of the motor drive pattern. Can be avoided. As a result, the gate opening / closing time can be shortened as much as possible, and the motor drive pattern can be reset more appropriately.

  In the hopper gate opening / closing apparatus according to the present invention, in the configuration, the controller determines a type of rotation operation of the stepping motor in the step-out step, and determines the type of step-out generated based on the determination result. Preferably, the controller is configured to determine which of the step-by-step command pulses is to be changed based on the type of step-out, and the controller may determine which step-out operation of the hopper gate is the step-out step. It is preferable to determine whether the timing corresponds to the timing, identify the type of the step-out that has occurred, and determine which of the step-specific command pulses to change based on the determination result. With these configurations, it is possible to deal with the step-out more precisely.

  In the hopper gate opening and closing device according to the present invention, in addition to the above configuration, the step-out determination unit is configured to output a difference between the actual measurement value and the specified value of the position change to the controller, and the controller includes: It is preferable that the degree of changing the step-by-step command pulse is determined from the difference obtained from the step-out determination unit. As a result, the reproducibility to the extent that the command pulse for each step is changed is improved, so that it is possible to take a more detailed countermeasure against the generated step-out.

  In the hopper gate opening / closing apparatus according to the present invention, in the configuration, the controller is configured to change the step-specific command pulse by changing at least one of the number of pulses and the pulse interval in each opening / closing step. It is preferable that the controller is configured to change the pulse interval by changing a pulse speed, which is the number of pulses per unit time. It is further preferable that at least one of the initial value and the final value of the pulse speed in the step is changed. As a result, the motor drive pattern can be reset so as to appropriately cope with the step-out caused by the inertial force of the stepping motor.

Further, in the hopper gate opening / closing apparatus according to the present invention, in addition to the above configuration, the opening / closing step includes a period during which the stepping motor is rotating at an accelerated speed, a period during which the stepping motor is rotating at a constant speed, a period during which the stepping motor is rotating at a reduced speed, and It is preferable that the opening / closing operation is divided for each period in which the rotation of the stepping motor is stopped. Further, in this configuration, if the step-out step identified by the step-out determination unit corresponds to a period during which the stepping motor is rotating at an accelerated speed or a reduced speed, the controller performs a plurality of opening / closing steps. More preferably, the step-by-step command pulse is changed so that the time required for the step corresponding to the step-out step is extended. In this case, the step-by-step command by the controller The pulse change is exemplified by a configuration that maintains the number of pulses in each of the opening / closing steps set in the step corresponding to the step-out step and lowers the initial value of the pulse speed that is the number of pulses per unit time. can do. Thereby, it is possible to more appropriately cope with the step-out caused by the inertial force of the stepping motor.

  In the hopper gate opening / closing apparatus according to the present invention, in the above-described configuration, the opening / closing step includes a period until the hopper gate is fully opened from a closed state, a period during which the hopper gate is fully opened, and the hopper gate is fully opened. The opening / closing operation may be divided for each period from the current state to the closing. Such classification based on the opening and closing of the hopper gate may be applied separately from the classification based on the rotation speed of the stepping motor, or may be applied in combination. In this case, the step-out step identified by the step-out determination unit corresponds to a period during which the stepping motor is rotating at a reduced speed, and also corresponds to a period from when the hopper gate is fully opened to when it is closed. If it is a step to perform, it is preferable that the controller is configured to change a motor stop time that is a time during which the hopper gate is maintained in a fully opened state, instead of changing the step-specific command pulse. . As a result, the motor drive pattern can be reset so that an appropriate countermeasure can be taken against a step-out that is not directly related to the stepping motor, for example, due to biting of the object to be weighed into the hopper gate.

  In the present invention, the specific configuration of the position sensor is not particularly limited, but an encoder may be mentioned as a particularly preferable configuration example. If it is an encoder, since the change in the position of the rotation shaft can be detected by the rotation angle, it can be provided not only on the rotation shaft of the stepping motor but also on the rotation shaft of the mechanism member constituting the gate opening / closing mechanism.

  The present invention also includes a weighing device including the hopper gate opening / closing device having the above-described configuration. The specific configuration of the weighing device according to the present invention is not particularly limited, but a typical example is a configuration in which the weighing device is a combination weigher. As a more preferable configuration example of this combination weigher, it includes a weighing hopper that accommodates and weighs an object to be weighed therein, and an operating device that operates the weighing device, and the hopper gate opening / closing device is provided in the weighing hopper. The storage device of the hopper gate opening / closing device is provided in accordance with at least one of the type of the object to be weighed and the amount of the object to be weighed in the weighing hopper. A plurality of the motor drive patterns to be set are stored, and the operating device is configured to be able to set at least one of the type of the object to be weighed and the accommodation amount, and the controller of the hopper gate opening / closing device Is one of the plurality of motor drive patterns based on at least one of the type of the object to be weighed and the accommodation amount set by the operation device. Mention may be made of the configuration you choose a.

  As described above, according to the present invention, the hopper gate provided in the weighing device is driven by the stepping motor, and even if the conditions associated with the operation of the weighing device are easily changed, the stepping motor is generated. There is an effect that it is possible to easily and effectively suppress the influence of the step-out.

It is a block diagram which shows an example of a structure of the hopper gate opening / closing apparatus which concerns on Embodiment 1 of this invention. It is a perspective view which shows an example of a specific structure at the time of applying the hopper gate opening / closing apparatus shown in FIG. 1 to the weighing hopper of a combination weigher. 2 is a graph showing temporal changes in rotational speed and direction of a stepping motor corresponding to an opening / closing operation of a hopper gate in the hopper gate opening / closing apparatus shown in FIG. 1. It is a flowchart which shows an example of the control which changes a motor drive pattern corresponding to the detection of a step-out performed by the control part of the hopper gate opening / closing apparatus shown in FIG. 5 is a flowchart showing an example of control for extending the time of an opening / closing step in the control shown in FIG. It is a block diagram which shows an example of a structure of the hopper gate opening / closing apparatus which concerns on Embodiment 2 of this invention. It is a perspective view which shows an example of a specific structure at the time of applying the hopper gate opening / closing apparatus shown in FIG. 6 to the weighing hopper of a combination weigher. 7 is a graph showing temporal changes in rotational speed and direction of a stepping motor corresponding to the opening / closing operation of the hopper gate in the hopper gate opening / closing apparatus shown in FIG. 6. It is a flowchart which shows an example of the control which changes a motor drive pattern corresponding to the detection of a step-out performed by the control part with which the hopper gate opening / closing apparatus shown in FIG. 6 is provided. 10 is a flowchart illustrating an example of control for determining whether a step-out step is one of opening / closing steps 1, 3 or 5 in the control illustrated in FIG. 9. 10 is a flowchart illustrating an example of control for extending the motor stop time in the opening / closing step 4 in the control illustrated in FIG. 9. It is a schematic diagram which shows an example of a structure of the combination scale which concerns on Embodiment 3 of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted.

(Embodiment 1)
[Configuration and basic operation of hopper gate opening and closing device]
FIG. 1 is a block diagram showing an example of the configuration of a hopper gate opening / closing device according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing an example of a specific configuration when the hopper gate opening / closing device shown in FIG. 1 is applied to a weighing hopper of a combination weigher.

  As shown in FIG. 1, the hopper gate opening / closing device 10A according to the present embodiment includes a stepping motor 11, a position detection sensor 12A, a motor drive circuit 13, a control unit 20, a link mechanism not shown in FIG. . The control unit 20 includes a calculation unit 21, a step-out determination unit 22, and a storage unit 23. The calculation unit 21 is connected to the step-out determination unit 22 and the storage unit 23, and is also connected to the motor drive circuit 13. It is connected. The motor drive circuit 13 is connected to the stepping motor 11. The step-out determination unit 22 is also connected to the position detection sensor 12A.

  The hopper gate opening / closing device 10A shown in FIG. 1 can be applied to a known weighing device, or a packaging device, a filling device, a dispensing device, and the like provided with the weighing device. In this embodiment, as shown in FIG. Furthermore, it is applied to a weighing hopper of a combination weigher. Specifically, in the gate opening / closing device 10A applied to the weighing hopper, a hopper gate 32 is provided on the lower side of the hopper main body 31, and the swing constituting the link mechanism so as to connect the hopper gate 32 and the stepping motor 11 is provided. A portion 14 and an arm portion 15 are provided. The arm portion 15 is attached to the hopper gate 32, the arm portion 15 is connected to the swing portion 14, and the swing portion 14 is in contact with a rotating shaft (not shown in FIG. 2) of the stepping motor 11.

  In the present embodiment, the stepping motor 11 and the swing portion 14 are fixedly supported by a case-like motor support portion 16 and the weight sensor 33 is fixed so as to be placed on the upper side of the motor support portion 16. Has been. The hopper body 31 is supported by the weight sensor 33 (not shown). Furthermore, a position detection sensor 12A for detecting a position (rotational position) associated with the rotation of the rotation shaft is located at a position opposite to the rotation shaft of the stepping motor 11 (side not fixed to the motor support portion 16). It is attached.

  The stepping motor 11 is a motor having a known configuration used for opening and closing a hopper gate. The position detection sensor 12A detects a change in the position of the rotating shaft of the stepping motor 11 and outputs the change to the control unit 20. In this embodiment, an encoder that detects the rotation angle of the rotating shaft is used as shown in FIG. It is done. In FIG. 1, this position detection is indicated by a dotted line. Here, the position detection sensor 12A detects the position itself (that is, directly detects the position), but may detect a parameter (physical quantity) having a correlation with the position (that is, the position is indirectly detected). May be detected). For example, the rotational speed and rotational acceleration may be detected. In these cases, the step-out determination unit 22 can obtain the position by first-order integrating the rotational speed or second-order integrating the rotational acceleration.

  The motor drive circuit 13 is composed of a plurality of switching elements and the like, and is also connected to a power supply via a power supply circuit and the like (not shown). The electric power supplied to the motor drive circuit 13 is converted into a command pulse by the motor drive circuit 13 under the control of the calculation unit 21 and supplied to the stepping motor 11. In this way, the motor drive circuit 13 drives the stepping motor 11 to rotate under the control of the calculation unit 21.

  The swing unit 14 and the arm unit 15 constitute a link mechanism, and transmit the rotational motion of the rotation shaft of the stepping motor 11 to the hopper gate 32. As the swing part 14 and the arm part 15, a known structure in the field of the hopper gate opening / closing device is adopted, but the link mechanism may include a structure other than the swing part 14 and the arm part 15, A configuration different from the arm portion 15 may be used.

  The swing unit 14 constituting the link mechanism is connected to the rotating shaft of the stepping motor 11 and converts the rotational motion of the rotating shaft into a swing motion. The arm portion 15 is in contact with the swing portion 14 and transmits the swinging motion of the swing portion 14 to the hopper gate 32 to open and close the hopper gate 32. In the present embodiment, the stepping motor 11 is attached to the inside of the case-like motor support portion 16 so that the swing portion 14 is supported in a swingable state and protrudes to the outside of the motor support portion 16. Has been supported. As a result, the rotation shaft of the stepping motor 11 is directed to the inside of the motor support portion 16, and the rotation shaft is connected to the swing portion 14 disposed on the inside.

  The motor support portion 16 has a case shape in the present embodiment, but is not limited to this. Of course, depending on the specific configuration of the hopper gate opening / closing device 10A, the stepping motor 11, the link mechanism, and the like. Any shape that can support or fix the configuration (weight sensor 33 or the like) may be used.

  The calculation unit 21 performs calculations related to the opening / closing operation of the hopper gate opening / closing device 10A, reads information from the storage unit 23 as necessary for the calculation process, and stores the results generated in the calculation process in the storage unit 23 as necessary. To do. The step-out determination unit 22 determines whether or not the stepping motor 11 has stepped out of the position change detected by the position detection sensor 12 </ b> A, and outputs it to the calculation unit 21. The calculation unit 21 receives the determination result from the step-out determination unit 22, performs a predetermined calculation process based on a predetermined program stored in the storage unit 23, and drives the driving pattern (motor) of the stepping motor 11 as described later. The drive pattern is changed.

  In the present embodiment, the calculation unit 21 and the storage unit 23 are constituted by a CPU of a microcomputer and an internal memory, respectively. Further, the step-out determination unit 22 may be a functional configuration of the control unit 20 and may be realized by the CPU as the calculation unit 21 operating according to a program stored in the storage unit 23. Alternatively, it may be configured as a logic circuit using a known switching element, arithmetic unit, comparator, or the like. In the present embodiment, as a preferred example, an embedded microcomputer configured to execute a pre-installed program can be employed as the control unit 20.

  A weighing hopper to which the hopper gate opening / closing device 10A is applied includes a hopper body 31, a hopper gate 32, and a weight sensor 33 in addition to the hopper gate opening / closing device 10A. The hopper main body 31 has a container-like shape in which an object to be weighed can be accommodated. In the present embodiment, the hopper main body 31 has a square shape with an opening on the upper side. A hopper gate 32 is provided in the lower part of the hopper main body 31, and the opening / closing operation is performed by transmitting the rotational driving force of the stepping motor 11 by the link mechanism (swing part 14 and arm part 15). In the present embodiment, the hopper gate 32 is a door-shaped gate that opens downward. The weight sensor 33 measures the weight of the object to be weighed accommodated in the hopper body 31, and a load cell is used in the present embodiment.

  Next, a basic operation of the hopper gate opening / closing device 10A having the above-described configuration will be described. First, the control unit 20 controls the motor drive circuit 13 by a predetermined calculation process in the calculation unit 21, and rotationally drives the stepping motor 11 with a predetermined drive pattern. The rotational driving force of the stepping motor 11 is converted into a swing motion by the swing portion 14, which is transmitted to the arm portion 15, whereby the hopper gate 32 is driven to open and close.

  On the other hand, a predetermined amount of an object to be weighed is supplied to the hopper body 31 from a supply hopper or an object weighing device supply device (not shown) with the hopper gate 32 closed. In this state, the weight sensor 33 measures the weight of the object to be weighed accommodated in the hopper body 31. After that, when the stepping motor 11 is rotationally driven by the control of the control unit 20, the rotational driving force of the rotational shaft is transmitted to the hopper gate 32 via the link mechanism (swing unit 14 and arm unit 15), whereby the hopper gate 32 is predetermined. Open / close operation. As a result, the objects to be weighed are discharged downward from the hopper body 31 when the hopper gate 32 is opened. Thereafter, when the hopper gate 32 is closed, the hopper body 31 enters a state of waiting for the supply of the object to be weighed.

  Here, along with the opening / closing operation of the hopper gate 32, the rotation angle of the rotation shaft of the stepping motor 11 is detected by the position detection sensor 12A and is output to the step-out determination unit 22 as shown in FIG. As will be described later, the step-out determination unit 22 determines whether or not a step-out has occurred in the stepping motor 11, and if it is determined that a step-out has occurred, the calculation unit 21 does not cause a step-out. Reset the motor drive pattern.

[Motor drive pattern]
Next, a motor drive pattern to be reset in the hopper gate opening / closing device 10A having the above-described configuration will be specifically described with reference to FIG. FIG. 3 is a graph showing temporal changes in the rotational speed and direction of the stepping motor 11 corresponding to the opening / closing operation of the hopper gate 32.

  The motor drive pattern is configured as a list of control data for executing a series of operations (opening / closing operations) from when the hopper gate 32 starts to open until it closes, and is stored in the storage unit 23. In the present embodiment, the motor drive pattern is organized as a set of a plurality of command pulses by dividing the opening / closing operation of the hopper gate 32 into a plurality of opening / closing steps and setting a command pulse for each opening / closing step.

  In the present embodiment, the opening / closing operation of the hopper gate 32 is divided into three opening / closing steps as shown in FIG. In the graph shown in FIG. 3, the vertical axis represents the rotation speed V of the stepping motor 11, and the horizontal axis represents the operation time t of the hopper gate 32. The center of the vertical axis is the rotation speed V = 0, that is, the state in which the stepping motor 11 is stopped. With this V = 0 as the boundary, the upper half of the graph shows the speed change when the stepping motor 11 is rotating forward. On the other hand, the lower half region of the graph is a region where the speed change when the stepping motor 11 rotates in the reverse direction is shown. In the present embodiment, the hopper gate 32 is opened when the stepping motor 11 is rotating forward, and the hopper gate 32 is closed when rotating reversely.

  Of the three opening / closing steps, the first opening / closing step (opening / closing step 1) is a step corresponding to a period during which the hopper gate 32 is being opened. At this time, the rotation axis of the stepping motor 11 is shown in FIG. As shown, it is rotating forward (V> 0). Next, the second opening / closing step (opening / closing step 2) is a step corresponding to a period in which the opening operation of the hopper gate 32 is completed and maintained in a fully opened state. At this time, the stepping motor 11 does not rotate. It has stopped. Next, the third opening / closing step (opening / closing step 3) is a step corresponding to a period in which the closing operation of the hopper gate 32 is performed, and at this time, the rotating shaft of the stepping motor 11 is reversely rotated (V < 0). Thus, the motor drive pattern is set by patterning the rotation operation of the stepping motor 11 so that the rotation direction of the stepping motor 11 changes at each opening / closing step.

  Here, as shown by the change in the solid line in FIG. 3, the actual rotation of the stepping motor 11 goes through acceleration, constant speed, and deceleration processes in any of the opening and closing operations. However, in the present embodiment, the motor drive pattern is patterned on the basis of the average value of rotation speed (average rotation speed Va) at each opening and closing step, as shown by the change of the alternate long and short dash line in FIG. Yes. Specifically, as shown in FIG. 3, the average rotational speed Va = + V1 in the opening / closing step 1, the average rotational speed Va = 0 in the opening / closing step 2, and the average rotational speed Va = −V1 in the opening / closing step 3. A motor drive pattern is set.

  Further, since the stepping motor 11 rotates in accordance with the command pulse output from the motor drive circuit 13, the motor drive pattern is stored in the storage unit 23 as command pulse information. In the present embodiment, since command pulses are set for the respective opening / closing steps, the motor drive pattern is organized as a set of step-specific command pulses set for the respective opening / closing steps. Specifically, in the opening / closing step 1, a step-by-step command pulse for the normal rotation of the stepping motor 11 is set, and in opening / closing step 3, a step-by-step command pulse for the reverse rotation of the stepping motor 11 is set. . Further, although the stepping motor 11 is stopped in the opening / closing step 2, in the present embodiment, the opening / closing step 2 is also regarded as a command pulse in which a low state in which a pulse is not output for a certain period of time continues, Assume that a pulse is set.

  As described above, the motor drive pattern in the present embodiment is organized from three command pulses, that is, a command pulse for each step of opening / closing step 1, a command pulse for each step of opening / closing step 2, and a command pulse for each step of opening / closing step 3. Information is stored in the storage unit 23. Therefore, at the time of rotation of the stepping motor 11, the calculation unit 21 reads out the motor drive pattern knitted by these three command pulses from the storage unit 23, and can input the command pulse according to this to the stepping motor 11. The motor drive circuit 13 is controlled.

  The command pulse is set by the number of pulses and the pulse interval, or various set values that can be converted into these. The number of pulses determines the rotation angle of the stepping motor 11, and the pulse interval determines the rotation speed (motor rotation speed) of the stepping motor 11. For example, in the present embodiment, a pulse motor configured to rotate at 0.9 ° / pulse is used as the stepping motor 11. Therefore, if the number of pulses Np = 100, the rotation angle φ of the stepping motor 11 = 90 °. Therefore, if Np = 200, φ = 180 °, if Np = 300, φ = 270 °, and if Np = 400, φ = 360 °.

  The pulse speed, which is the number of pulses per unit time, corresponds to the reciprocal of the pulse interval, and therefore determines the motor rotation speed. Therefore, the pulse speed is included in the set value that can be converted into the number of pulses and the pulse interval. Since the pulse speed and the motor rotation speed have a proportional relationship, it is an effective setting value for adjusting the speed of the opening / closing operation of the hopper gate 32. Generally, pps (Pulse Per Second) which is the number of pulses generated per second (number of pulses / second) is used as a unit of pulse speed. If the pulse speed is 1000 pps, for example, the reciprocal pulse interval is 1/1000 s, that is, 1 ms.

  In the motor drive pattern shown in FIG. 3, the forward and reverse rotations of the stepping motor 11 are important elements. This forward / reverse rotation is realized by changing the command pulse pattern. For example, when a command pulse is input in a simple one-phase excitation pattern for a unipolar stepping motor (model with stator poles consisting of X and X ~ and Y and Y ~) If the command pulse input at the time is a pattern in which the pulse goes high in the order of X, Y, X ~, Y ~, the command pulse input at the time of reverse rotation will be Y ~, X ~, Y, X What is necessary is just to change so that it may become the pattern replaced in order. Therefore, the step-by-step command pulses for knitting the motor drive pattern only need to be composed of at least the number of pulses, the pulse interval, and the pulse pattern. However, in this embodiment, since it is not necessary to change the forward / reverse direction of rotation in order to cope with the step-out of the stepping motor 11, the conditions for changing the command pulse are the number of pulses and the pulse interval. (Or a set value that can be converted into these).

[Detection of out-of-step and coping with step-out]
Next, detection of whether or not a step-out has occurred in the stepping motor 11 that rotates with the motor drive pattern and a countermeasure when the step-out occurs will be described with reference to FIGS. 3, 4, and 5. explain. 4 and 5 are flowcharts illustrating an example of control performed by the control unit 20 to reset the motor drive pattern in response to step-out detection.

  First, although the motor drive pattern described above is shown as a simplified pattern in the graph shown in FIG. 3, in the present embodiment, the storage unit 23 of the control unit 20 stores the types of objects to be weighed and A basic pattern adapted to the quantity is stored. This basic pattern is read out by the calculation unit 21 and used for controlling the stepping motor 11.

  Specifically, as in the present embodiment, when the hopper gate opening / closing device 10A is applied to a weighing hopper of a combination weigher, depending on the type or amount of objects to be weighed accommodated in the hopper body 31, The opening / closing speed and timing of the hopper gate 32, the length of the fully opened time, and the like are changed.

  As for the types of objects to be weighed, even if they are in the form of powder, they are fluid (depending on shape, size, etc.) ) Will be different, so these shapes and sizes will be taken into consideration. Or, when the object to be weighed is “lumped”, the shape is not uniform like meat pieces and the surface is viscous, the shape is relatively similar like root vegetables and fruits, and the surface is dry Comparing things etc., even if the weight is the same, there is a difference in the time of discharging (falling) downward when the hopper gate 32 is opened, and the object to be weighed is nearly spherical with a long object to be weighed (eg carrot) Similar differences can occur when comparing objects (eg potatoes). In addition, the amount of the object to be weighed needs to be increased as the weight increases, but in the case of different materials, the weight may be the same, but the volume may be different. Become.

  Here, even when the stepping motor 11 is rotated based on the motor drive pattern corresponding to the type and amount of the object to be weighed, the stepping motor 11 may be stepped out due to the influence of other conditions. For example, if the combination weigher has a configuration in which different types of weighing hoppers can be exchanged, the configuration of the weighing hopper (capacity of the hopper body 31, the weight of the hopper body 31 itself, the shape of the hopper body 31, the configuration of the hopper gate 32, etc. ), It is necessary to adjust the speed and the like.

  In addition, even if the same type of objects to be weighed are weighed with the weighing hopper of the same configuration, if the environment (temperature, humidity, etc.) on which the combination weigher is placed is different, adjust the speed etc. Need to be done.

  Thus, the combination of conditions to be considered is enormous. Therefore, in the present embodiment, a plurality of types of basic motor drive patterns (basic patterns) based on combinations of typical conditions are set in advance. When the combination weigher is operated, an appropriate one is selected from a plurality of basic patterns by, for example, the operation unit or the input unit of the combination weigher, and then automatically adjusted by control of step-out detection accompanying the operation of the combination weigher. Thus, the motor drive pattern is reset. Of course, only one basic pattern may be set according to the application of the combination weigher, the configuration of the weighing hopper, or the like.

  Next, a specific method for resetting the motor drive pattern when a step-out occurs will be described. As shown in FIG. 3, the stepping motor 11 is rotationally driven when the hopper gate 32 is opened or closed, and is stopped while the hopper gate 32 is fully opened. Therefore, since step-out cannot occur in the opening / closing step 2 among the opening / closing steps 1 to 3, the steps to be reset are the opening / closing steps 1 and 3.

  Here, in any of the opening / closing steps 1 and 3, step-out hardly occurs when the stepping motor 11 rotates at a constant speed (period of V = ± V1). That is, the stepping motor 11 is likely to step out when accelerating or decelerating, and the cause is often due to an inertial force due to insufficient torque of the stepping motor 11. In this case, in order to cope with the occurrence of the step-out, the pulse interval may be increased to such an extent that a sufficient torque can be obtained. Therefore, in the present embodiment, in the opening / closing step 1 or 3, the step corresponding to the opening / closing step (step-out step) in which the step-out has occurred is controlled by increasing the pulse interval.

  Note that the extent to which the pulse interval is lengthened may be based on the degree of position change detected by the position detection sensor 12A. In this case, the calculation unit 21 may be configured to acquire position change data via the step-out determination unit 22 and calculate the length of the pulse interval from the position change data based on a predetermined program. If the length of the pulse interval with respect to the degree of position change is preset in stages and stored in the storage unit 23 as a look-up table (LUT), and the calculation unit 21 obtains the position change data, the LUT of the storage unit 23 It may be configured to reference a suitable length of the pulse interval. If the LUT is used, it is possible to efficiently change the pulse interval by omitting each calculation.

  Further, if the pulse interval is simply increased, the time required for each opening / closing step is also increased. As a result, the opening / closing time (gate opening / closing time) of the hopper gate 32 is increased as a whole. If the gate opening / closing time becomes long, the opening / closing operation of the hopper gate 32 becomes slow, and it becomes impossible to cope with the high speed of the combination weigher. On the other hand, in the method using the LUT, a pulse interval that prevents the gate opening / closing time from becoming excessively long can be set in advance. Therefore, it is possible to avoid a situation where the opening / closing operation of the hopper gate is delayed, and it is possible to simplify the control for resetting the motor drive pattern. Of course, even in the configuration in which the calculation unit 21 calculates the length of the pulse interval, a program adapted to prevent the gate opening / closing time from becoming too long can be used.

  Next, control for resetting the motor drive pattern by the control unit 20 will be described. As shown in FIG. 4, the calculation unit 21 of the control unit 20 selects an optimal one of a plurality of basic patterns, reads it from the storage unit 23 (step S <b> 101), and controls the motor driving circuit 13 to control the stepping motor. 11 is driven to rotate in a basic pattern (step S102). Along with this rotational drive, the step-out determination unit 22 of the control unit 20 monitors the detection result (change in the rotation angle) by the position detection sensor 12A and determines whether or not step-out has occurred (step S103). . If no step-out has occurred, the monitoring of the change in the rotation angle is repeated (NO in step S103).

  On the other hand, if the occurrence of step-out is determined (YES in step S103), the calculation unit 21 determines whether the step-out has occurred or not (step-out step) based on the comparison between the step-out occurrence timing and the basic pattern configuration. ) Is the opening / closing step 1 among the opening / closing steps 1 to 3 (step S104). If the step-out step is the opening / closing step 1 (YES in step S104), a processing for changing the pulse interval is performed in the opening / closing step 1 (step S105). If the step-out step is the opening / closing step 3 (NO in step S104), a process of changing the pulse interval is performed in the opening / closing step 3 (step S106). After the process of changing the pulse interval in the opening / closing step 1 or 3, the stepping motor 11 is rotationally driven with the changed motor drive pattern (change pattern) (return to step S102). Thereafter, this control is repeated until the weighing operation by the combination weigher is completed.

  In the present embodiment, the process of changing the pulse interval (step S105 or S106) is a method using an LUT as shown in FIG. First, the calculation unit 21 acquires position change data from the step-out determination unit 22 (step S501), and refers to the pulse interval corresponding to the position change data from the LUT in the storage unit 23 (step S502). Then, the calculation unit 21 determines which of the opening / closing steps 1 to 3 corresponds to the step-out step, selects a command pulse of the opening / closing step corresponding to the step-out step (step S503), and based on the referenced pulse interval. Then, the pulse interval is changed in the command pulse of the selected opening / closing step (step S504), and the process ends.

  Thus, according to the present embodiment, the motor drive pattern is set for the opening / closing operation of the hopper gate 32, the occurrence of step-out at each opening / closing step is determined, and each command pulse organized as the motor drive pattern is determined. Is configured to change. Therefore, it is possible not to detect the step-out generated in the stepping motor 11 and simply feed it back, but to perform control so as to cope with the occurrence of the step-out in view of the entire opening / closing operation of the hopper gate 32. Therefore, even in the situation where various conditions accompanying the operation of the combination weigher are easily changed, the influence of the step-out generated in the stepping motor 11 can be easily and effectively suppressed.

  In the present embodiment, the hopper gate opening / closing device 10A is exemplified as a configuration applied to a weighing hopper of a combination weigher. Of course, the hopper gate opening / closing device 10A may be applied to a supply hopper of a combination weigher, or applied to a hopper of another weighing device. May be.

  Further, in the present embodiment, as a method of resetting the motor drive pattern, only the method of increasing the pulse interval is exemplified, but of course not limited to this, for example, depending on the step-out situation, A method of changing the number of pulses in the opening / closing step 1 or 3 may be used, or a method of changing the pulse speed may be used. In the case of the method of changing the pulse speed, the acceleration or deceleration may be changed, or the pulse speed may be changed so as to change the average rotation speed of the stepping motor 11 in each opening / closing step.

(Embodiment 2)
In the first embodiment, the configuration in which the position detection sensor is attached to the stepping motor has been described. However, in this embodiment, the position detection sensor is attached to the link mechanism unit and not only the motor drive pattern is reset, but also the gate. A configuration for automatically controlling the shortening of the opening / closing time will be described.

[Configuration of hopper gate opening and closing device]
FIG. 6 is a block diagram showing an example of the configuration of the hopper gate opening / closing device according to Embodiment 2 of the present invention. FIG. 7 is a perspective view showing an example of a specific configuration when the hopper gate opening / closing device shown in FIG. 6 is applied to a weighing hopper of a combination weigher.

  As shown in FIGS. 6 and 7, the basic configuration of the hopper gate opening / closing device 10B according to the present embodiment is the same as that of the hopper gate opening / closing device 10A according to the first embodiment. Since the sensor 12B, the motor drive circuit 13, the control unit 20, the swing unit 14 and the arm unit 15 as a link mechanism, and the motor support unit 16 are provided and applied to the weighing hopper of the combination weigher, the hopper body 31 A hopper gate 32 and a weight sensor 33 are also provided.

  Here, in the hopper gate opening / closing device 10B, the position detection sensor 12B is not attached to the stepping motor 11, but is attached to the rotating shaft of the swing portion 14 as shown in FIG. In FIG. 6, the stepping motor 11 and the swing unit 14 are mechanically connected by connecting with a double line, and the swing unit 14 by the position detection sensor 12 </ b> B is similar to FIG. 1. The change in the position of the rotation axis is indicated by a dotted line.

  Since the position detection sensor 12B is attached to the rotation shaft of the swing portion 14, the position detection sensor 12B detects a position change in the operation of the link mechanism accompanying the opening / closing operation of the hopper gate 32. In this case, for example, when an object to be weighed in the hopper gate 32 during the opening / closing operation of the hopper gate 32, it is possible to detect a change in position due to this biting. If the position detection sensor 12A is directly attached to the stepping motor 11 as in the first embodiment, most of the position change is canceled by backlash or the like in the link mechanism. However, in the configuration of the present embodiment, since the change in the position of the link mechanism is directly detected, it is possible to detect the occurrence of step-out due to the object to be weighed in the hopper gate 32. Become.

  The hopper gate opening / closing device 10B is also provided with a timer 17 as shown in FIG. The timer 17 is bidirectionally connected to the calculation unit 21 of the control unit 20, and the calculation unit 21 controls the timer 17 and acquires time information measured by the timer 17. The timer 17 may be configured as a known timer circuit, or a configuration realized by the CPU as the calculation unit 21 operating according to a program stored in the storage unit 23, that is, a functional configuration of the control unit 20. May be.

[Motor drive pattern]
Next, the motor drive pattern to be reset in the hopper gate opening / closing device 10B having the above-described configuration will be specifically described with reference to FIG. FIG. 8 is a graph showing temporal changes in the rotational speed and direction of the stepping motor 11 corresponding to the opening / closing operation of the hopper gate 32. Note that the vertical axis, horizontal axis, and illustrated area of the graph are basically the same as those of the graph shown in FIG.

  In the first embodiment, the opening / closing operation of the hopper gate is performed by three opening / closing steps: a period during which the hopper gate 32 is opened, a period during which the hopper gate 32 is maintained in the fully opened state, and a period during which the closing operation is performed. However, in the present embodiment, each of the opening operation period and the closing operation period is further divided into three according to the difference in the motor rotation speed, and is divided into a total of seven opening / closing steps. Yes.

  Specifically, the first opening / closing step (opening / closing step 1) corresponds to a period in which the opening operation of the hopper gate 32 is performed and the stepping motor 11 is accelerated and rotated forward. It is a step. In this step, the rotation speed of the stepping motor 11 is accelerated at a constant acceleration from V = 0 to V = + V2. Next, the second opening / closing step (opening / closing step 2) is a period in which the opening operation of the hopper gate 32 is performed, and the period in which the stepping motor 11 is rotating forward at a constant speed (V = + V2). Is a step corresponding to. Next, the third opening / closing step (opening / closing step 3) is a step corresponding to a period during which the opening operation of the hopper gate 32 is performed and the stepping motor 11 is decelerating and rotating forward. is there. In this step, the rotation speed of the stepping motor 11 is decelerated at a constant acceleration from V = + V2 to V = 0.

  Next, the fourth opening / closing step (opening / closing step 4) is a step corresponding to a period in which the opening operation of the hopper gate 32 is completed and maintained in a fully opened state. This step corresponds to the opening / closing step 2 in the first embodiment, and the stepping motor 11 stops without rotating.

  Next, the fifth opening / closing step (opening / closing step 5) is a step corresponding to a period during which the hopper gate 32 is closed and the stepping motor 11 is accelerated and reversely rotated. is there. In this step, the rotation speed of the stepping motor 11 is accelerated at a constant acceleration from V = 0 to V = −V2. Next, the sixth opening / closing step (opening / closing step 6) is a period in which the closing operation of the hopper gate 32 is performed, and the stepping motor 11 is reversely rotated at a constant speed (V = −V2). It is a step corresponding to a period. Next, the seventh opening / closing step (opening / closing step 7) is a step corresponding to a period in which the closing operation of the hopper gate is performed and the stepping motor 11 is decelerating and reversely rotating. . In this step, the rotation speed of the stepping motor 11 is decelerated at a constant acceleration from V = −V2 to V = 0.

  As described above, the motor drive pattern in the present embodiment is stored in the storage unit 23 as information knitted from the seven command pulses called the step-specific command pulses of the opening / closing steps 1 to 7. Therefore, at the time of rotation of the stepping motor 11, the calculation unit 21 reads a motor drive pattern knitted from these seven command pulses from the storage unit 23, and can input a command pulse according to the motor drive pattern to the stepping motor 11. The motor drive circuit 13 is controlled.

[Detection of out-of-step and coping with step-out]
Next, in the stepping motor 11 that rotates with the motor drive pattern, detection of whether or not step-out has occurred and countermeasures to be taken when step-out occurs are shown in FIG. 8, FIG. 9, FIG. Based on 9, 10, and 11 are flowcharts illustrating an example of the control performed by the control unit 20 to reset the motor drive pattern in response to the detection of step-out.

  First, also in the present embodiment, as in the first embodiment, a plurality of types of basic motor drive patterns (basic patterns) based on combinations of typical conditions are set in advance. When the combination weigher is operated, an appropriate one is selected from a plurality of basic patterns by, for example, the operation unit or the input unit of the combination weigher, and then automatically adjusted by control of step-out detection accompanying the operation of the combination weigher. Thus, the motor drive pattern is reset. Of course, only one basic pattern may be set according to the application of the combination weigher, the configuration of the weighing hopper, or the like.

  Next, a specific method for resetting the motor drive pattern when a step-out occurs will be described. As shown in FIG. 8, the stepping motor 11 rotates when the hopper gate 32 is opened or closed, and is stopped while the hopper gate 32 is fully opened. Therefore, step-out cannot occur in the opening / closing step 4 among the opening / closing steps 1 to 7. Further, as described above, the step-out motor 11 is unlikely to step out when rotating at a constant speed. Therefore, in the present embodiment, it is determined whether the step-out step is one of the opening / closing steps 1, 3, 5, and 7, and the step-by-step command pulse that is knitted as a motor drive pattern according to the determination result. Control to change.

  Here, in the present embodiment, since the position detection sensor 12B is attached to the rotating shaft of the swing portion 14, as described above, the step detection sensor 12B detects the step-out caused by the bite of the object to be weighed into the hopper gate 32. be able to. Such biting occurs before the completion of the closing operation of the hopper gate 32, and therefore occurs in the opening / closing step 7 of the opening / closing steps 1-7. The step-out caused by such biting is caused by the opening / closing operation of the hopper gate opening / closing device 10B, and therefore cannot be dealt with even if the step-specific command pulse set in the opening / closing step 7 is changed. The reason why the biting occurs is that the object to be weighed is not completely discharged during the period when the hopper gate 32 is fully opened. Therefore, in order to cope with the occurrence of the step-out, the opening / closing step 4 may be extended. Therefore, in this embodiment, if it is determined that the step-out step corresponds to the opening / closing step 7, this is dealt with by extending the motor stop time. In the present embodiment, as in the first embodiment, the LUT is used to change the pulse interval and the motor stop time.

  In the first embodiment, the length of the pulse interval stored as the LUT is set as a value so that the gate opening / closing time does not become excessively long. However, in the present embodiment, the timer 17 is provided. Therefore, the gate opening / closing time can be actually measured and used for control by the control unit 20. Therefore, the length of the pulse interval and the length of the motor stop time stored as the LUT are not limited to values considering the gate opening / closing time, and should be set as values that can reliably cope with step-out. Can do. Therefore, it is possible to improve the degree of freedom and versatility in the control.

  Next, control for resetting the motor drive pattern by the control unit 20 will be described. As shown in FIG. 9, the calculation unit 21 of the control unit 20 selects an optimal one of a plurality of basic patterns, reads it from the storage unit 23 (step S201), and controls the motor drive circuit 13 to control the stepping motor. 11 is driven to rotate in a basic pattern (step S202). Along with this rotation drive, the step-out determination unit 22 of the control unit 20 monitors the detection result (change in the rotation angle) by the position detection sensor 12A and determines whether or not step-out has occurred (step S203). . If no step-out has occurred, the monitoring of the change in the rotation angle is repeated (NO in step S203).

  On the other hand, if the occurrence of step-out is determined (YES in step S203), the calculation unit 21 determines whether the step-out has occurred or not (step-out step) based on the comparison between the step-out occurrence timing and the basic pattern configuration. ) Is the opening / closing step 7 among the opening / closing steps 1 to 7 (step S204). If the step-out step is the opening / closing step 7 (YES in step S204), processing for extending the opening / closing step 4 (that is, processing for extending the motor stop time) is performed (step S205).

  If the step-out step is not the opening / closing step 7 (NO in step S204), it is determined whether the step-out step corresponds to the opening / closing step 1, 3 or 5, and processing for changing the pulse interval is performed (step S206). ). After performing the extension process of the opening / closing step 4 or the pulse interval changing process in the opening / closing step 1, 3 or 5, the stepping motor 11 is rotationally driven by the motor drive pattern (processed pattern) after the process. The gate opening / closing time is measured (S207), and it is determined whether or not the gate opening / closing time is within a preset allowable range (S208).

  If within the allowable range (YES in step S208), the changed motor drive pattern (change pattern) is confirmed, and the stepping motor 11 is rotationally driven (return to step S202). If it is not within the allowable range (NO in step S208), the gate opening / closing time is shortened by a predetermined ratio (step S209), the change pattern is confirmed, and the stepping motor 11 is driven to rotate (return to step S202). Thereafter, this control is repeated until the weighing operation by the combination weigher is completed. As for step-out detection, it is also possible to employ a method in which only the opening / closing step 4 is extended by setting a fastest motor drive pattern that does not cause step-out by performing a trial run several times.

  The process of determining whether the step out step corresponds to one of the opening / closing steps 1, 3 or 5 (step S206) will be described. As shown in FIG. It is determined whether or not (step S601). If it is opening / closing step 1 (YES in step S601), processing for changing the pulse interval in opening / closing step 1 is performed (step S602). On the other hand, if the step-out step is not the opening / closing step 1 (NO in step S601), it is determined whether or not the step-out step is the opening / closing step 3 (step S603). If it is opening / closing step 3 (YES in step S603), a process of changing the pulse interval is performed in opening / closing step 3 (step S604). If it is opening / closing step 5 (NO in step S603), the pulse interval is changed in opening / closing step 5. A change process is performed (step S605). The process for changing the pulse interval is the same as the process shown in FIG. 5 described in the first embodiment. If the pulse interval changing process is executed in any of the opening / closing steps, this determination process is terminated.

  Further, the extension process of the opening / closing step 4 will be described. As shown in FIG. 11, the calculation unit 21 acquires the position change data from the step-out determination unit 22 (step S511), and the position change from the LUT of the storage unit 23. The motor stop time corresponding to the data is referred to (step S512). And the calculating part 21 changes the motor stop time of the opening / closing step 4 based on the referred motor stop time (step S513), and complete | finishes this process.

  In shortening the gate opening / closing time (step S209), for example, apart from the pulse interval changing process and the motor stop time extending process, a shortening process LUT is stored in the storage unit 23 in advance, and this LUT is referred to. Thus, the pulse interval and motor stop time of the opening / closing step that has been changed or extended may be reduced at a ratio that does not affect the response to the step-out, or the opening / closing operation of the hopper gate 32 may be performed. Processing that shortens the time of other opening / closing steps from the whole may be used.

  The control for the step-out described above will be described in more detail with a specific example. First, a countermeasure against the step-out caused by the inertial force of the stepping motor 11 will be described with reference to the following Table 1. As shown in Table 1, in each open / close step 1-7, the number of pulses and the pulse speed or the motor stop time are set as the motor drive pattern, and the position change of the rotation axis of the stepping motor 11 at this time It is assumed that the increase / decrease of the rotation angle is detected by the detection sensor 12B.

  In the opening / closing step 1 of Table 1, the initial speed is 800 pps, and the pulse speed changes until the final speed reaches 1000 pps during 40 pulses. That is, in this example, the pulse speed increases every (1000−800) ÷ 40 = 5 pps / pulse. Further, since the stepping motor 11 rotates at 0.9 ° / pulse as described in the first embodiment, the rotation angle in the opening / closing step 1 is 0.9 ° × 40 = 36 °. Note that the number of pulses, the pulse speed, and the rotation angle are the same in the other steps, and thus description thereof is omitted.

  When the stepping motor 11 is rotationally driven by the motor driving circuit 13 and the hopper gate 32 is opened / closed (steps S201 to S202), the opening / closing step 1 has a default value of + 36 ° for the increase / decrease of the rotation angle. On the other hand, if the measured value detected by the position detection sensor 12B is + 34 °, the measured value is different by 2 ° from the predetermined value, so the step-out determination unit 22 determines that step-out has occurred (step S203). ). In this case, since the step-out step corresponds to the opening / closing step 1, the calculation unit 21 performs control to change the motor drive pattern so as to increase the pulse interval in the opening / closing step 1 (steps S204 and S206).

  Here, in Table 1, since the pulse speed is set instead of the pulse interval in the motor drive pattern, and the pulse speed is the reciprocal of the pulse interval, the pulse speed is changed. Furthermore, in Table 1, not the average speed but the initial speed and the final speed are set as the pulse speed, and the final speed corresponds to the pulse speed during the constant speed rotation of the opening / closing step 2. Therefore, the calculation unit 21 refers to the LUT stored in the storage unit 23 and reduces the initial speed of the opening / closing step 1 from, for example, 800 pps to, for example, 600 pps. As a result, the pulse interval of the initial speed of the opening / closing step 1 is extended from 1.25 ms (1/800 pps) to 1.67 ms (1/600 pps) to cope with the step-out caused by the inertial force of the stepping motor 11. it can. Thereafter, if the control shown in FIG. 9 is performed, the opening / closing operation of the hopper gate 32 is executed. If the gate opening / closing time is within the allowable range, the calculation unit 21 determines the changed motor drive pattern and exceeds the allowable range. If so, the gate opening / closing time may be shortened (steps S207 to S209).

  Next, a countermeasure against the step-out caused by the object to be weighed in when the hopper gate 32 is closed will be described with reference to Table 2 below. The motor drive pattern shown in Table 2 is basically the same as the motor drive pattern shown in Table 1, but the initial pulse speed is lowered from 800 pps to 600 pps in the opening / closing step 1 and the pulse interval is increased. Has been done. Further, the maximum speed during the closing operation (V = −V2 in FIG. 8) is −1,300 pps.

  When the stepping motor 11 is rotationally driven by the motor driving circuit 13 and the hopper gate 32 is opened / closed (steps S201 to S202), the specified value for the increase / decrease of the rotation angle in the opening / closing step 7 is −36 °. On the other hand, if the measured value detected by the position detection sensor 12B is −33 °, the measured value is different by 3 ° from the predetermined value, so the step-out determination unit 22 determines that step-out has occurred ( Step S203). In this case, since the step-out step corresponds to the opening / closing step 7, the calculation unit 21 performs control to increase the motor stop time in the opening / closing step 4 (steps S204 and S205). That is, the calculation unit 21 refers to the LUT stored in the storage unit 23 and extends the motor stop time set in the opening / closing step 4 from 100 ms to, for example, 120 ms. As a result, the time during which the hopper gate 32 is open is extended, so that the step-out caused by the bite of the object to be weighed can be dealt with. Thereafter, if the control shown in FIG. 9 is performed, the opening / closing operation of the hopper gate 32 is executed. If the gate opening / closing time is within the allowable range, the calculation unit 21 determines the changed motor drive pattern and exceeds the allowable range. If so, the gate opening / closing time may be shortened (steps S207 to S209).

  As described above, according to the present embodiment, not the change in the position of the rotation shaft of the stepping motor 11 but the change in the motor drive pattern is detected by detecting the change in the position of the link mechanism. It is possible to effectively cope with a step-out caused by the biting of an object to be weighed or the like which is not directly caused. Since the timer 17 is separately provided, the gate opening / closing time can be shortened as much as possible by repeating the opening / closing operation of the hopper gate 32 so that the pulse interval and the motor stop time are increased to such an extent that no step-out occurs. It can be adjusted automatically.

  In the present embodiment, as in the first embodiment, the timer 17 may not be provided, and the processing in steps S207 to S209 shown in FIG. 9 may not be performed. Further, in the present embodiment, the case where the occurrence of the step-out due to the biting is detected is exemplified, but the stepping motor 11 that is not directly caused by the stepping motor 11 depending on the configuration of the hopper gate opening / closing device 10B or the hopper to which the hopper gate is applied. It may be configured to detect the occurrence of a key. Further, in the present embodiment, the opening / closing operation of the hopper gate 32 is divided into seven opening / closing steps 1 to 7 on the basis of the rotation speed of the stepping motor 11, but is divided into a number other than 7 steps on the basis of other conditions. The motor drive pattern may be reset.

(Embodiment 3)
In the first or second embodiment, the case where the hopper gate opening / closing device 10A or 10B is applied to the weighing hopper of the combination weigher has been described by illustrating only the weighing hopper. For example, as a combination weigher including the weighing hopper, A configuration as shown in FIG.

  As shown in FIG. 12, the combination weigher according to the present embodiment includes a supply device that supplies an object to be weighed (not shown), a top cone 41 that distributes the object to be weighed supplied from the supply device, and supplies it downstream. A plurality of linear feeder pans 42 that receive the objects to be weighed from the cone 41 and supply downstream, a plurality of supply hoppers 43 that collectively supply the objects to be weighed supplied from the linear feeder pans 42 at a predetermined timing, and a supply hopper 43 A plurality of weighing hoppers 30 for receiving and weighing the objects to be weighed from the weighing hoppers 30, receiving and collecting the objects to be weighed from the weighing hoppers 30, and feeding them downstream; Stepping motor 45 that opens and closes the hopper gate provided, and stepping motor that opens and closes the hopper gate provided below the weighing hopper 30 1, a weight sensor 33 for measuring the weight of the objects to be weighed inside the weighing hopper 30, the operation setting display section 47 and setting the conditions to manipulate the combination weigher, and the combination weigher control unit 48 or the like. In addition, about the concrete structure of the said combination scale, since a well-known structure is employable, the description is abbreviate | omitted.

  In the present embodiment, at least the hopper gate opening / closing device 10A or 10B may be applied to the weighing hopper 30, and further, the hopper gate opening / closing device 10A or 10B may be applied to the supply hopper 43. In this case, the control unit 20 of the hopper gate opening / closing device 10A or 10B only needs to be integrated with the combination weigh control unit 48, and a storage unit (not shown) connected to the combination weigh control unit 48 includes a plurality of units. A basic pattern of the motor drive pattern is stored.

  When the operator of the combination weigher sets various conditions such as the type of the object to be weighed and the weight of the object to be weighed by the weighing hopper 30 on the operation setting display unit 47, the combination weigher control unit 48 Depending on the contents, an appropriate one is selected from a plurality of basic patterns, and the weighing operation is started. If a step-out occurs in the stepping motor 11 (or stepping motor 45) during the weighing operation, the motor drive pattern is re-started from the basic pattern to deal with the step-out as described in the first or second embodiment. Set. As a result, measurement errors due to step-out can be significantly suppressed, and an efficient and highly accurate weighing operation can be performed.

  In the above description, the combination weigher is exemplified as the weighing device, but it goes without saying that a weighing device other than the combination weigher may be used. The present invention can be suitably used as long as the weighing device has a configuration including at least a hopper gate. Needless to say, the present invention can also be applied to a packaging device, a packaging system, a filling device, a dispensing device, a manufacturing plant, and the like, which are further provided with a weighing device including a hopper gate.

  Further, the present invention is not limited to the description of each of the above-described embodiments, and various modifications can be made within the scope shown in the claims, and different embodiments and a plurality of modified examples are respectively provided. Embodiments obtained by appropriately combining the disclosed technical means are also included in the technical scope of the present invention.

  The present invention is not only suitable for use in the field of hopper gate opening and closing devices for opening and closing hopper gates, but also suitable for various weighing devices to which the hopper gate opening and closing device can be applied, such as a combination weigher equipped with weighing hoppers. Can be used.

10A Hopper gate opening and closing device 10B Hopper gate opening and closing device 11 Stepping motor 12A Position detection sensor (position sensor)
12B Position detection sensor (position sensor)
13 Motor drive circuit 14 Swing part (link mechanism, gate opening / closing mechanism, mechanism member)
15 Arm (link mechanism, gate opening / closing mechanism, mechanism member)
17 Timer (timer)
20 Control unit (controller)
21 arithmetic unit 22 step-out determination unit (step-out determination unit)
23 Memory unit (memory device)
30 Weighing hopper 32 Hopper gate 43 Supply hopper 45 Stepping motor 47 Operation setting display section (operator)
48 Combination Weighing Control Unit (Controller)

Claims (16)

A stepping motor,
An openable hopper gate,
A gate opening and closing mechanism for opening and closing the hopper gate in response to the rotational force of the stepping motor;
A position sensor provided on a rotation shaft of the stepping motor or a mechanism member constituting the gate opening / closing mechanism, and detecting a position in rotation of the rotation shaft or a position in operation of the mechanism member;
A motor driving circuit for driving the stepping motor by outputting a command pulse to the stepping motor;
When the measured value of the position change detected by the position sensor is compared with a preset specified value of the position change when the hopper gate is opened and closed, and there is a difference between these values A step-out determination unit that determines that step-out has occurred in the stepping motor;
A memory,
A controller, and
The memory stores a motor drive pattern which is information for continuously changing the command pulse so as to pattern the operation of the stepping motor in response to the opening / closing operation of the hopper gate,
The controller controls the motor drive circuit to drive the stepping motor based on the motor drive pattern and drives the motor if the step-out determiner determines that the step-out has occurred. Configured to reset the pattern ,
Further, the step-out determination unit divides one opening / closing operation of the hopper gate into a plurality of opening / closing steps, and compares the measured value of the position change with the specified value for each opening / closing step. Configured to determine the occurrence of a tone and identify the step determined to have occurred as a step-out step,
The motor drive pattern stored in the memory is organized as a set of step-specific command pulses set for each of the opening / closing steps,
The controller determines which of the plurality of opening / closing steps corresponds to the step-out step, and based on the determination result, at least one of the plurality of step-by-step command pulses organized as the motor drive pattern. A hopper gate opening and closing device configured to change either . The controller determines the type of rotational operation of the stepping motor in the step-out step, identifies the type of step-out that has occurred based on the determination result, and determines the step-by-step type from the type of step-out. The hopper gate opening and closing device according to claim 1 , wherein the hopper gate opening and closing device is configured to determine which of the command pulses is changed. The controller determines at which timing the step-out step corresponds to the opening / closing operation of the hopper gate, identifies the type of step-out that has occurred based on the determination result, and the step-by-step command pulse The hopper gate opening and closing device according to claim 1 , wherein the hopper gate opening and closing device is configured to determine which one of the two is to be changed. The step-out determination device is configured to output a difference between the measured value and the specified value of the position change to the controller,
4. The hopper gate according to claim 1, wherein the controller is configured to determine a degree of changing the step-by-step command pulse from the difference obtained from the step-out determination unit. 5. Switchgear. Wherein the controller, by changing at least one of the number of pulses and pulse interval in the respective opening and closing step, is configured for changing the step-by-step command pulse, according to any one of claims 1 4 Hopper gate opening and closing device. The hopper gate opening and closing device according to claim 5 , wherein the controller is configured to change the pulse interval by changing a pulse speed, which is the number of pulses per unit time. The hopper gate opening / closing device according to claim 6 , wherein the controller is configured to change at least one of an initial value and a final value of the pulse speed in each opening / closing step. The opening / closing step includes the opening / closing step every period during which the stepping motor is rotating at an accelerated speed, a period during which the stepping motor is rotating at a constant speed, a period during which the stepping motor is rotating at a reduced speed, and a period during which the rotation of the stepping motor is stopped. The hopper gate opening and closing device according to any one of claims 1 to 7 , wherein the hopper gate opening and closing device is configured by dividing an operation. If the step-out step identified by the step-out determination unit corresponds to a period during which the stepping motor is rotating at an acceleration or deceleration, the controller performs the step-out step among the plurality of opening / closing steps. The hopper gate opening and closing device according to claim 8 , wherein the step-by-step command pulse is changed so that a time required for a corresponding step is extended. The change in the step-by-step command pulse by the controller maintains the number of pulses in each opening / closing step set in the step corresponding to the step-out step, and the pulse speed is the number of pulses per unit time . 10. The hopper gate opening / closing device according to claim 9 , wherein the initial value is lowered. The opening / closing step includes the opening / closing step every period from the closed state of the hopper gate to the fully opened state, a period of maintaining the hopper gate in the fully opened state, and a period of time from the fully opened state to the closing of the hopper gate. The hopper gate opening and closing device according to any one of claims 1 to 10 , wherein the hopper gate opening and closing device is configured by dividing an operation. The step-out step identified by the step-out determination unit may be a step corresponding to a period during which the stepping motor is rotating at a reduced speed and a period from when the hopper gate is fully opened to when it is closed. If
12. The hopper gate opening / closing according to claim 11 , wherein the controller is configured to change a motor stop time, which is a time that the hopper gate is maintained in a fully opened state, instead of changing the step-specific command pulse. apparatus. A timer for measuring at least an opening / closing operation time which is a time required for one opening / closing operation of the hopper gate;
The storage device further stores an allowable range of the opening / closing operation time,
The said controller is comprised so that the said motor drive pattern may be reset so that the said opening / closing operation | movement time measured by the said timer may be in the said tolerance | permissible_range. The hopper gate opening and closing device described in 1. A weighing device comprising the hopper gate opening and closing device according to any one of claims 1 to 13 . 15. The weighing device according to claim 14 , wherein the weighing device is a combination weigher. A weighing hopper for accommodating and weighing an object to be weighed therein, and an operating device for operating the weighing device,
The hopper gate opening and closing device is provided for opening and closing a gate provided in the weighing hopper,
The storage device of the hopper gate opening / closing device stores a plurality of motor drive patterns set according to at least one of the type of the object to be weighed and the amount of the object to be weighed in the weighing hopper. And
The operation device is configured to be able to set at least one of the type of the object to be weighed and the accommodation amount,
The controller of the hopper gate opening / closing device is configured to select any one of the plurality of motor drive patterns based on at least one of the type of the object to be weighed and the accommodation amount set by the operation device. The metering device according to claim 14 or 15 .

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