JP6213521B2 - Method for calculating effective mass of luggage during earthquake in automatic warehouse and rack design method for automatic warehouse - Google Patents

Description

  The present invention relates to a method for calculating an effective mass of a load during an earthquake in an automatic warehouse, and a rack design method for an automatic warehouse.

The rack warehouse includes a unit-type rack warehouse (hereinafter referred to as “unit-type”) in which independent racks are installed in a general building, and a building-type rack warehouse (hereinafter referred to as “building-type”) in which the roof and walls are directly attached to the rack. There is.
As a seismic response analysis method for a building rack, a technique for obtaining stress acting on each part of the rack by simulation is known (see Patent Document 1).

JP 2000-310581 A

  Building racks are still being used for design that is far from the actual load of rack warehouses, using the specifications (load capacity) of general buildings under the Building Standards Act.

  An object of the present invention is to make it possible to appropriately design a rack of an automatic warehouse by accurately grasping the actual situation of the load load of the rack warehouse.

  Hereinafter, a plurality of modes will be described as means for solving the problems. These aspects can be arbitrarily combined as necessary.

The method for calculating the effective mass of a load at the time of an earthquake in an automatic warehouse according to an aspect of the present invention includes the following steps.
◎ Placement step for placing the load on the shaking table ◎ Excitation step for inputting horizontal vibration to the shaker on which the load is placed ◎ Relationship acquisition step for obtaining the relationship between acceleration and horizontal force in the excitation step ◎ Effective mass calculation step that calculates the effective mass of the load during an earthquake based on the relationship between acceleration and horizontal force

  In this method, the effective mass related to the slipping and dancing of the load at the time of the earthquake occurring in the automatic warehouse is obtained without conducting a large-scale experiment (effective mass calculating step). As a result, it is possible to properly design the rack of an automatic warehouse by accurately grasping the actual situation of the load capacity of the rack warehouse.

In the vibration step, an actuator is used to apply vibration to the shaking table in the horizontal direction.
In the relationship calculating step, the relationship between the acceleration and the force may be calculated using a force necessary for the actuator to apply vibration to the vibration table.

In the relationship calculation step, for the same input acceleration, the horizontal force reduction rate, which is the ratio of the horizontal force when the load is not fixed to the shake table with respect to the horizontal force when the load is fixed to the shake table, is calculated.
The effective mass calculation step may calculate the effective mass of the load at the time of the earthquake using the horizontal force reduction rate.

An automatic warehouse rack design method according to another aspect of the present invention includes the following steps.
◎ Method of calculating the effective mass above ◎ Step of designing the rack of the automatic warehouse using the calculated effective mass By designing the rack of the automatic warehouse using the calculated effective mass, for example, an appropriate strength can be obtained. The rack that has it can be realized, thereby reducing the cost.

  According to the present invention, it is possible to appropriately design a rack of an automatic warehouse by accurately grasping the actual situation of the loaded load of the rack warehouse.

The schematic block diagram of the measuring instrument in one Embodiment of this invention. The schematic block diagram of the measuring instrument at the time of luggage non-fixation. The control block diagram of a measuring device. The flowchart of the horizontal force measurement control by a measuring device. The table | surface which shows the measurement result of the horizontal force and energy at the time of fixation and non-fixation. The graph which shows the relationship between input acceleration and horizontal force. The graph which shows the relationship between input acceleration and energy. The flowchart which shows the design method of the rack of an automatic warehouse.

1. First Embodiment (1) Outline of the Present Embodiment In the present embodiment, for example, the influence (damping effect) on the rack structure at the time of an earthquake is determined by vibration experiments and the response to the actual situation. A static structure calculation method based on load conditions will be described.

(2) Device Configuration of Measuring Instrument A measuring instrument 1 used in an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a measuring instrument according to an embodiment of the present invention.
The measuring device 1 is a uniaxial shaking table controlled by an actuator (ACT).
The measuring device 1 has a vibration table 3. The vibration table 3 is a member that can vibrate in the horizontal direction. The vibration table 3 is supported by the support table 5 so as to be capable of vibrating in the left-right direction in FIG. The vibration table 3 has a main body 7. The main body 7 is placed on the support base 5. The vibration table 3 has a mounting table 9. The mounting table 9 is a member on which the luggage W is mounted. The mounting table 9 is fixed on the main body 7.

The measuring device 1 has an actuator 11. The actuator 11 is a vibration device that generates a vibration force in the horizontal direction. The actuator 11 is disposed on the side of the vibration table 3. The actuator 11 has a power transmission unit 13 connected to the vibration table 3. As an example, the actuator 11 is a servo actuator.
The measuring device 1 has a load cell 15. The load cell 15 is a sensor that measures a load. Specifically, the load cell 15 measures the horizontal force during excitation. The load cell 15 is provided in the power transmission unit 13 of the actuator 11.

The measuring device 1 has a first accelerometer 17 (FIG. 3). The first accelerometer 17 is a sensor for measuring the acceleration of the vibration table 3. As an example, the first accelerometer 17 is a piezoelectric pickup accelerometer.
The measuring device 1 has a second accelerometer 19 (FIG. 3). The second accelerometer 19 is a sensor for measuring the acceleration of the load W placed on the vibration table 3. As an example, the first accelerometer 17 is a piezoelectric pickup accelerometer.

The measuring device 1 has a first displacement meter 21 and a second displacement meter 22. The first displacement meter 21 is a sensor for measuring the horizontal displacement of the load W with respect to the vibration table 3. The second displacement meter 22 is a sensor for measuring the horizontal displacement of the main body 7 of the vibration table 3 with respect to the support table 5. As shown in FIG. 1, the first displacement meter 21 is provided on the main body 7 of the vibration table 3. The 2nd displacement meter 22 is provided on the support stand 5, as shown in FIG. As an example, the first displacement meter 21 and the second displacement meter 22 are laser displacement determination sensors.
In FIG. 1, a luggage W is mounted on the measuring device 1. Specifically, the luggage W is placed on the pallet P. The pallet P is placed on the mounting table 9.

(3) Control configuration of measuring device The control configuration of the measuring device will be described with reference to FIG. FIG. 3 is a control configuration diagram of the measuring device.
The measuring device 1 has a controller 23. The controller 23 is connected to the actuator 11. The controller 23 can transmit a control signal to the actuator 11. The controller is connected to the first accelerometer 17, the second accelerometer 19, the first displacement meter 21, and the second displacement meter 22, and can receive detection signals from these sensors.
More specifically, the controller 23 is a computer having a CPU, a RAM, and a ROM, and performs various controls by executing a program. The controller 23 has a memory 25 that can store data.

(4) Outline of Experimental Method An experimental method using the measuring device 1 will be described. The purpose of this experimental method is to reproduce the acceleration generated in the upper layer at the time of an earthquake on the ground surface, and to grasp the change in load by horizontal force. In a normal rack structure experiment, since a property of each layer is measured at the same time, an actual structure test specimen is generally used. However, in this experiment, in order to grasp the property of the luggage itself more accurately, the vibration model composed of the carriage on which the luggage is placed is not adopted, without using the upper vibration table and the structural model in which the luggage swings in the lower center. By adopting a structural model in which vibration is transmitted from the drive source to the table through the elastic link and the cart and the baggage slide in the horizontal direction, the excitation force on the sliding baggage is measured. The building vibrates when subjected to earthquake motion, because the inertial force opposite to the acceleration of the earthquake motion acts on the building. Generally, this inertial force is treated as an external force acting on the building, and this is called an earthquake load.
Then, when a phenomenon such as a load slipping or dancing in the rack warehouse occurs, the inertial force of the load is reduced. Such a phenomenon is considered as an effective mass with respect to the inertial force of the load itself. In order to perform static calculation in consideration of the sliding of the load, it is necessary to grasp the layer in which the load slides and the effective mass ratio. Therefore, in the method of the vibration experiment using the measuring device 1, the layer on which the load slides and the effective mass ratio are grasped based on data obtained by actually vibrating the load.

(5) Excitation force measurement method In this experiment, the force (inertial force) acting on the building is regarded as the horizontal force of the shaking table when the load slides during an earthquake, and the force that the load itself gives to the building is measured. .
Hereinafter, two types of loading states will be described with reference to FIGS. FIG. 2 is a schematic configuration diagram of the measuring device when the load is not fixed.

In FIG. 1, the luggage W is placed on the mounting table 9 together with the pallet P, and the pallet P is immovable in the horizontal direction with respect to the mounting table 9 by the fixing jig 31 (fixed state).
In FIG. 2, the luggage W is placed on the mounting table 9 together with the pallet P, and the pallet P is movable in the horizontal direction with respect to the mounting table 9 (non-fixed state).
For the two types of loading states described above, the input acceleration is vibrated from 100 gal to 350 gal in increments of 50 gal to obtain data. As an example, the waveform of the input value is a sine wave, and the frequency is 1.11 Hz.

  The horizontal force measurement control by the measuring device will be described with reference to FIG. FIG. 4 is a flowchart of horizontal force measurement control by the measuring device. Note that the flowchart of FIG. 4 is an example, and the presence and order of each step is not particularly limited. Further, a plurality of steps may be executed simultaneously or partially overlapping.

In step S1, the luggage W is placed on the placing table 9 together with the pallet P (a placing step for placing the luggage on the vibrating table).
In step S <b> 2, the luggage W is fixed to the mounting table 9 together with the pallet P.
In step S3, the controller 23 sets acceleration.

In step S <b> 4, the controller 23 transmits a control signal to the actuator 11 to drive the actuator 11. As a result, the actuator 11 applies horizontal vibration to the vibration table 3 (excitation step of inputting horizontal vibration to the vibration table on which the load is placed).
In step S5, the controller 23 receives the detection signal from the load cell 15 to measure the horizontal force. The horizontal force is a force necessary for the actuator 11 to apply vibration to the vibration table 3.
Further, the controller 23 receives the detection signal from the second displacement meter 22 to measure the displacement amount of the vibration table 3. The controller 23 calculates energy from the displacement amount and the horizontal force.

In step S <b> 6, the cargo W and the pallet P are released from the mounting table 9.
In step S <b> 7, the controller 23 transmits a control signal to the actuator 11 to drive the actuator 11.
In step S8, the controller 23 receives the detection signal from the load cell 15 to measure the horizontal force. Further, the controller 23 receives the detection signal from the second displacement meter 22 to measure the displacement amount of the luggage W. The controller 23 calculates energy from the displacement amount and the horizontal force.

In step S9, the controller 23 calculates a horizontal force reduction rate from the horizontal force at the time of fixation and the horizontal force at the time of non-fixation (relation acquisition step of acquiring the relationship between acceleration and horizontal force by the excitation step). That is, for the same input acceleration, the horizontal force reduction rate is obtained by calculating the ratio of the horizontal force when the load W is not fixed to the vibration table with respect to the horizontal force when the load W is fixed to the vibration table. The controller 23 further stores both horizontal forces and the horizontal force reduction rate in the memory 25. Further, the controller 23 calculates an energy reduction rate from the energy at the time of fixation and the energy at the time of non-fixation. The controller 23 further stores both energy and the energy reduction rate in the memory 25. In this method, necessary data is obtained based on the operation in the experiment.
In step S10, it is determined whether measurement has been completed for all accelerations. If completed (Yes in step S10), the measurement is completed. If not completed (No in step S10), the process returns to step S2. In this manner, the horizontal force when fixed and the horizontal force when not fixed and the horizontal force reduction rate are obtained for each acceleration. Moreover, the energy at the time of fixation, the energy at the time of non-fixation, and an energy reduction rate are obtained for each acceleration.

In the above embodiment, the horizontal force at the time of fixation and the horizontal force at the time of non-fixation are measured for each acceleration, but as another example, the horizontal force is measured with different accelerations in the fixed state, and then the acceleration is measured in the non-fixed state. Different horizontal forces may be measured. A calculated value may be used as the horizontal force at the time of fixing.
In the above embodiment, the horizontal force at the time of non-fixing is measured after the measurement of the horizontal force at the time of fixing. As another example, the horizontal force at the time of fixing may be measured after measuring the horizontal force at the time of non-fixing.

In the above embodiment, the horizontal force reduction rate is calculated for each acceleration. As another example, after calculating the fixed horizontal force and the non-fixed horizontal force for all accelerations, the horizontal force reduction for all accelerations is collectively performed. The force reduction rate may be calculated.
In the above embodiment, the energy measurement and the energy reduction rate are calculated, but these may be omitted as another example.

A measurement result is demonstrated using FIGS. FIG. 5 is a table showing measurement results of horizontal force and energy when fixed and when not fixed. FIG. 6 is a graph showing the relationship between input acceleration and horizontal force. FIG. 7 is a graph showing the relationship between input acceleration and energy.
The determination of whether or not there is a load slip in FIG. 5 is based on the change in waveform that occurs at 300 gal. Further, the reduction rate of the horizontal force and energy represents the ratio of the non-fixed value to the fixed value.

In the range of input acceleration of 100 to 250 gal, the load W and the vibration table 3 vibrate as a whole (that is, no load slip occurs). Therefore, the non-fixed horizontal force is almost the same as the fixed horizontal force. However, in the range of the input acceleration of 300 to 350 gal, load slip occurs (that is, the load W slides on the vibration table 3). Therefore, the non-fixed horizontal force is smaller than the fixed horizontal force. That is, the horizontal force reduction rate is increased. Specifically, it can be seen that the horizontal force has a reduction effect of 26% to 53%. Therefore, the reduction effect due to the sliding of the load W can be quantitatively confirmed by measuring the change in the horizontal force.
In the range of input acceleration of 100 to 250 gal, no load slip occurs. Therefore, the non-fixed energy is almost the same as the fixed energy. However, load slip occurs in the range of input acceleration of 300 to 350 gal. Therefore, the non-fixed energy is smaller than the fixed energy. That is, the energy reduction rate is increased.

(6) Method for designing rack for automatic warehouse (6-1) Outline of design method A method for designing a rack for automatic warehouse will be described. In the primary design, first, the load / external force is calculated. Specifically, a fixed load, a loaded load, wind pressure, and seismic force are calculated. In the primary design, stress analysis is subsequently performed. Specifically, long-term stress and short-term stress are calculated. In the primary design, the allowable stress level is further confirmed. Specifically, long-term stress and short-term stress are confirmed.
In secondary design, confirmation of interlayer deformation angle, confirmation of rigidity, confirmation of eccentricity, reinforcement of brace stress, prevention of fracture of brace ends and joints, prevention of local buckling, fracture of column base Preventing and securing the yield ratio of cold-formed square steel pipe columns.
In addition, said design method is an example and is not specifically limited.

(6-2) Details of Design Method A method (first design described above) for designing a rack of an automatic warehouse using the calculated effective mass will be described with reference to FIG. FIG. 8 is a flowchart showing a method for designing a rack of an automatic warehouse. Part or all of this control may be executed by the controller 23 or may be executed by another controller.
In step S21, as a result of the above vibration experiment, the effective mass of the load at the time of the earthquake, that is, the effective mass ratio corresponding to the acceleration and acceleration of the actual load slide is grasped using the horizontal force reduction rate. Specifically, from the vibration experiment or actual data, grasp the acceleration of the load and the effective mass at the time of sliding according to the acceleration (calculate the effective mass of the load at the time of the earthquake based on the relationship between the acceleration and the horizontal force) Effective mass calculation step). It should be noted that the package characteristics can be grasped by repeating the experiment, and an approximate value can be selected based on the past experimental results at the time of designing.
As an example, the effective mass ratio of the sliding acceleration 300 gal is 80%, the effective mass ratio of the sliding acceleration 400 gal is 70%, and the effective mass ratio of the sliding acceleration 500 gal is 60%.

In step S22, the response acceleration of each layer of the automatic warehouse rack at the time of the earthquake is calculated using static calculation. Specifically, based on Article 88 of the Building Standard Law Enforcement Order, each layer seismic force _Pi is calculated by the following formula.
_{P i = Q i -Q i +} 1 (Q i: earthquake layer shear force of each layer)
Q _i = C _i × ΣW _i (C _i : layer shear force coefficient in each layer, ΣW _i : cumulative mass up to each layer).
C _i = Z × R _t × A _i × C ₀ (Z: regional coefficient, R _t : vibration characteristic coefficient, A _i : seismic layer shear force coefficient building height according to building vibration characteristics It is a value indicating the distribution of directions, C ₀ : standard shear force coefficient).

Each layer acceleration a _i is calculated by the following equation.
F = m × a (F: force, m: mass, a: acceleration), that is, a = F / m,
a _i = P _i / (DL _i + LL ′ _i ) (DL _i : each layer fixed load, LL ′ _i : each layer load)

  In step S23, the response acceleration value of each layer is compared with the response acceleration value at which load slip occurs in the vibration experiment, and it is determined whether or not there is a layer exceeding the acceleration at which the load slides. Thereby, the layer which should be multiplied by the effective mass ratio of the loaded load is specified. If there is a layer that exceeds the acceleration with which the load slides (Yes in step S23), the process proceeds to step S24. If there is no layer that exceeds the acceleration at which the load slides (No in step S23), the process proceeds to step S25.

  In step S24, an automatic warehouse rack is designed in consideration of the effective mass due to load sliding. In step S25, an automatic warehouse rack is designed as usual.

As described above, by calculating the effective mass at the time of the earthquake and designing the rack of the automatic warehouse, for example, a rack having an appropriate strength can be realized, thereby reducing the cost.
More specifically, in the above-described method, a static external force is calculated based on a dynamic experiment (placement step and vibration step) (relation acquisition step). Therefore, the effective mass of the load at the time of the earthquake occurring in the automatic warehouse is obtained without conducting a large-scale experiment (effective mass calculation step). As a result, it is possible to properly design the rack of an automatic warehouse by accurately grasping the actual situation of the load capacity of the rack warehouse. More specifically, the rigidity of the rack can be reduced as compared with the conventional design method. As a result, the weight of the material can be reduced, and the construction cost can be further reduced.

2. Other Embodiments Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. In particular, a plurality of embodiments and modifications described in this specification can be arbitrarily combined as necessary.

  The present invention can be widely applied to a method for calculating an effective mass of a load at the time of an earthquake in an automatic warehouse and a rack design method for an automatic warehouse.

1: Measuring device 3: Shaking table 5: Supporting table 7: Body 9: Mounting table 11: Actuator 13: Power transmission unit 15: Load cell 17: First accelerometer 19: Second accelerometer 21: First displacement meter 22: Second displacement meter 23: Controller 25: Memory 31: Fixing jig

Claims (4)

A method for calculating the effective mass of a load at the time of an earthquake in an automatic warehouse,
A placing step of placing the load on a shaking table;
An excitation step of inputting horizontal vibration to the shaking table on which the load is placed;
A relationship calculating step of calculating a relationship between acceleration and horizontal force in the vibration step;
An effective mass calculating step of calculating an effective mass of the load at the time of an earthquake based on a relationship between the acceleration and a horizontal force;
An effective mass calculation method comprising: The exciting step applies vibration in the horizontal direction to the shaking table using an actuator,
2. The effective mass calculation method according to claim 1, wherein the relationship calculation step calculates a relationship between the acceleration and a horizontal force using a force necessary for the actuator to apply the vibration to the vibration table. The relationship calculation step calculates a horizontal force reduction rate that is a ratio of a horizontal force when the load is not fixed to the shaking table with respect to a horizontal force when the load is fixed to the shaking table for the same input acceleration,
The effective mass calculation method according to claim 2, wherein the effective mass calculation step calculates the effective mass of the load at the time of an earthquake using the horizontal force reduction rate. The effective mass calculation method according to any one of claims 1 to 3,
Designing an automated warehouse rack using the calculated effective mass;
Rack design method for automatic warehouse with

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