JP2004074601A - Motor-driven potter's wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably maintain a rotary table in a locked state or rotation-free state of a rotary table even without installing a timer and prevent a porcelain from being broken. <P>SOLUTION: This motor-driven potter's wheel is equipped with a rotary table 2, a motor 30 for driving the rotary table 2, a pedal 3 fitted to a device body in a freely rotating manner, a speed setting part 70 which outputs a command speed value complying with the treading level of the pedal 3, a command speed judgement part 80 for comparing the command speed value with a first threshold value and a second threshold value which is lower than the first threshold value, an inverter 110 and a drive circuit 120 which control the drive of the motor 30 so as to make the rotary speed of the rotary table 2 reach the command speed value. The inverter 110 and the drive circuit 120 stop the excitation of the motor 30 when the command speed level is below the first threshold value and set the rotary table 2 free when the command speed level is below the second threshold value, according to the instructions of the command speed judgement part 80. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric potter's wheel device used for making pottery.
[0002]
[Prior art]
In the pottery industry, an electric powered potter's wheel that rotates a rotary table by electricity is widely used. The electric potter's wheel device has a rotary table on which clay is placed, a motor for driving the rotary table, a pedal for adjusting the rotational speed of the rotary table, and the rotational speed of the motor at the level of the speed command signal. A drive control unit for controlling the drive of the motor so as to achieve a corresponding rotation speed. The potter can rotate the rotary table at a desired speed by rotating the pedal in the vertical direction using, for example, feet and adjusting the rotation position of the pedal.
[0003]
FIG. 12 is a graph showing the relationship between the rotational speed of the rotary table and the speed command signal of the conventional electric wheel apparatus, wherein the vertical axis shows the rotational speed of the rotary table and the horizontal axis shows the command speed. . When the potter puts his / her foot on the pedal located at the home position and depresses the pedal, the speed command signal rises and the rotary table starts to rotate immediately. When the pedal is further depressed, the rotary table rotates at a rotation speed corresponding to the depression amount. On the other hand, when the pedal is returned to the home position, the rotation speed of the rotary table decreases.
[0004]
When the pivot position of the pedal returns to the home position, the rotary table stops and the rotary table cannot be moved (locked state). In the locked state, the timer is activated, and when a predetermined time elapses, the excitation to the motor is stopped, and the rotary table can be manually moved (rotation free state).
[0005]
[Problems to be solved by the invention]
By the way, the potter may perform the pottery work while holding the foot on the pedal while maintaining the locked state or the rotation-free state. The placed foot must be weakened and held so that the pedal stays at the home position. If you weaken your feet, the potter may unintentionally step on the pedal due to tremors and other effects. Also, potters are so obsessed with pottery that they unconsciously put their feet on their feet and step on the pedal.
[0006]
As described above, in the conventional electric powered wheel apparatus, the rotary table cannot be locked unless the pedal is returned to the home position. Therefore, the pedal is brought to the home position with the foot placed on the pedal. If kept, the foot may be unstable, chattering is likely to occur, and a timer must be provided. On the other hand, when the pedal is depressed to some extent, an appropriate force is applied to the foot, so that the foot does not wobble and the pedal can be stably maintained at that position.
[0007]
The present invention has been made in order to solve such problems, and can stably maintain the rotary table in a locked state or a rotation-free state without providing a timer. On the other hand, an object of the present invention is to provide an electric powered wheel apparatus that prevents the rotating table from rotating and prevents the ceramic from being damaged.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, an electric wheel apparatus according to the present invention includes a rotary table that rotates on a horizontal plane that is exposed and rotated at an upper portion of the apparatus body, and a motor that rotationally drives the rotary table. A pedal connected to the outside of the apparatus main body and capable of being depressed by an operator's foot, and a drive control means for driving the motor at a speed corresponding to the depression level. When the threshold value is 1 or less, the rotary table is locked, and when the stepping level is further lowered to become a second threshold value that is smaller than the first threshold value, the rotary table is rotated. It is characterized by being in a free state.
[0009]
According to this configuration, since the locked state and the rotation free state can be adjusted stepwise while the pedal is depressed to some extent, when the locked state is reached, the timer is operated and counted for a predetermined time, and then the rotation free state is reached. As in the case of a conventional electric powered wheeling machine, it is prevented that the potter automatically enters the rotation-free state without being aware of it. As a result, the potter accurately grasps the rotation-free state. While making ceramics, you can do it.
[0010]
The electric wheel apparatus according to the present invention is connected to the outside of the apparatus main body, a rotary table that rotates on a horizontal plane that is exposed and rotated at the upper part of the apparatus main body, a motor that rotates the rotary table, and A pedal capable of being depressed by an operator's foot, and drive control means for driving the motor at a speed corresponding to the depression level, and when the pedal depression level of the pedal increases, the drive control means When the level is equal to or higher than the first threshold value, the rotary table is rotated, and when the pedal depression level is lowered, when the level is equal to or lower than the first threshold value, the rotary table is set in a locked state, and the level is The rotary table is set in a rotation-free state when it becomes equal to or smaller than a second threshold value smaller than the first threshold value.
[0011]
In this case, since the hysteresis is provided, when performing the ceramic work with the foot placed on the pedal, the interval between the pedal position where the lock table is turned to the rotation free state and the pedal position where the rotary table starts to rotate is set. By taking enough, unstable operation due to chattering can be prevented.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, FIG. 1 is an external view showing an embodiment of an electric powered wheel apparatus according to the present invention. In FIG. 1, the electric powered wheel apparatus includes a housing 1 and a rotary table 2 provided at an upper portion thereof so as to be rotatable around a vertical axis, and the housing 1 is pivotally supported on a lower side of the side surface thereof. The speed adjusting pedal 3, the power switch 5 provided at an appropriate side surface, the fixing stopper 6 provided at a predetermined position on the bottom surface, and the rotation direction of the turntable 2 provided above the power switch 5 And a switch 8 for switching between. An outlet for the power cable 7 is formed below the power switch 5.
[0013]
The pedal 3 has a shape on which an operator's foot can be placed, and is supported so as to be able to rotate with a horizontal shaft (not shown) that is pivotally supported at the lower end portion thereof. A horizontal axis (not shown) is connected to a potentiometer inside the housing 1 so as to generate a voltage corresponding to the depression amount of the pedal 3. The lever 4 has the same function as the pedal 3.
[0014]
FIG. 2 is a side cross-sectional view of the electric wheel apparatus shown in FIG. As shown in FIG. 2, in the electric powered wheel apparatus, a motor 11 is attached in a vertical position in a housing 1. The motor 11 includes a stator 12 and a rotor 13 that is coaxial with the stator 12 and disposed on the inner side. The stator 12 includes a cup-shaped stator hub 121 having a lower opening, and a coil 122 composed of three phases U, V, and W arranged on the inner peripheral surface of the stator hub 121. The rotor 13 is composed of a cup-shaped rotor hub 131 having an upper opening, and a rotor magnet 132 in which S and N poles are alternately arranged on the outer peripheral surface of the rotor hub 131 so as to face the coil 122. . A through hole 1a is preceded on the upper surface of the housing 1, and a bearing 141 having a flange portion is provided here. A motor shaft 14 that is vertically exposed from the upper surface of the housing 1 is supported in the bearing. The rotary table 2 is attached to the upper part of the motor shaft 14 so that rotation is possible.
[0015]
A holder 15 through which the motor shaft 14 is penetrated is fastened to the upper surface of the housing 1 by, for example, two bolts 16. A lever 19 for adjusting the height of the rotary table 2 is attached on the motor shaft 14 and above the holder 18. Further, a rotary encoder 21 for detecting the position of the rotor 13 is attached to the lower end of the motor shaft 14.
[0016]
The rotary encoder 21 generates a pulse signal for the position detection unit 60 to detect the position of the rotor 13 with a resolution finer than the arrangement pitch of the rotor magnets 132. It is possible to detect with a pulse.
[0017]
The motor 11 is an inner type motor in which the rotor 13 is disposed inside the stator 12, and is a DD (direct drive motor) that directly rotates the rotary table by the motor shaft 14.
[0018]
In the electric powered wheel apparatus configured as described above, when an exciting current is applied to the coil 122, a magnetic field is generated between the rotor 13 and the stator 12, and the rotor 13 and the motor shaft 14 are rotated by this magnetic field. As a result, the turntable 2 connected to the motor shaft 14 rotates.
[0019]
A predetermined number of, for example, three Hall sensors 40 (see FIG. 3) are attached at appropriate positions of the stator. The Hall sensor 40 detects the relative position of the rotor magnet 132 with respect to the stator 12 by detecting a change in the magnetic field between the rotor 13 and the stator 12.
[0020]
FIG. 3 shows a block diagram of the rotary drive system of the potter's wheel apparatus. The rotational drive system includes a CPU, a ROM, and a RAM, and the CPU executes processing of each functional unit.
[0021]
The speed detection unit 50 sequentially detects the edges of the pulse signal output from the rotary encoder 21 and calculates the rotational speed of the motor 30 from the detection cycle.
[0022]
The position detection unit 60 includes a counter and obtains the position of the rotor 13 based on the pulse signal output from the rotary encoder 21 and the pulse signal output from the hall sensor 40. Specifically, when detecting the edge of the pulse signal output from the hall sensor 40, the position detection unit 60 resets the counter, starts counting the pulse signal output from the rotary encoder 21, and sets the count value. Output. This count value is the number of pulses of the pulse signal output from the rotary encoder 21 based on the position of the rotor magnet 132 detected by the hall sensor 40. Therefore, if the number of pulses of the pulse signal output from the rotary encoder 21 is counted, the position of the rotor 13 can be specified. The position detector 60 may detect the position of the rotor 13 with higher accuracy (resolution) by counting the frequency of the pulse signal output from the rotary encoder 21 by, for example, multiplying it by four.
[0023]
The speed setting unit 70 stores a voltage signal output from the pedal 3 in association with a command speed value determined according to the level of the voltage signal in the ROM. When receiving the voltage signal output from the pedal 3, the speed setting unit 70 reads out a command speed value corresponding to the level of the voltage signal from the ROM. In the present embodiment, as shown in FIG. 4, the command speed value is set based on a function in which the value linearly increases as the level of the voltage signal increases.
[0024]
The command speed determination unit 80 receives the command speed value from the speed setting unit 70, and compares the level of the command speed value with a predetermined first threshold value and a second threshold value that is smaller than the first threshold value. As a result, an excitation signal that makes the rotation speed of the motor 30 zero is output, or excitation to the motor 30 is stopped. The inverter 110 instructs the inverter 110 to output an excitation signal so that the rotation speed of the turntable 2 becomes 0 when the level of the command speed value corresponding to the comparison amount becomes lower than the first threshold value. When the level of the command speed value becomes lower than the second threshold value, the inverter 110 is instructed to stop the excitation of the coil 122.
[0025]
The subtraction unit 90 calculates a difference between the command speed output from the potentiometer of the pedal 3 and the detection speed output from the speed detection unit 50, and outputs this difference to the PI control unit 100.
[0026]
The PI control unit 100 is output from the proportional unit 101 that multiplies the difference between the detection speed and the command speed by a predetermined amount, the integration unit 102 that integrates the signal output from the proportional unit 101, and the proportional unit 101 and the integration unit 102. An adder 103 for adding signals is generated, and a speed control signal in which the gain of the difference is increased or the like is generated in order to more accurately match the command speed value and the detected speed.
[0027]
The inverter 110 stores a memory 1101 that stores an amplitude value of a sine waveform with respect to the position (count value) of the rotor 13 detected by the position detection unit 60, an output value of the three-phase UVW from the memory 1101, and a control from the PI control unit 100. Three multiplying units 1102 for multiplying the speed value, and three PWM control units 1103 for converting each output value from the multiplying unit 1102 into an analog signal, thereby controlling the voltage of each phase, The current is controlled in a sine wave shape.
[0028]
Instead of the above sine waveform, a waveform including a high-order harmonic in a sine wave may be used. Further, when the command speed determination unit 80 instructs the inverter 110 to stop the excitation of the coil 122, the inverter 110 stops the output of the excitation signal to the drive circuit 120.
[0029]
The drive circuit 120 includes a total of six switching elements for both positive and negative poles for switching energization of each phase of the three-phase UVW, and energizes the three-phase coils 122U, 122V, and 122W of the motor 30 in the forward and reverse directions. By cutting off, the sine ideal for a motor realizes smooth rotation in a form close to driving.
[0030]
As shown in FIG. 5, the drive circuit 120 drives switching elements UH and UL for driving a U-phase coil, switching elements VH and VL for driving a V-phase coil, and a W-phase coil. Switching elements WH and WL. As the switching elements UH, VH and WH, for example, pnp type bipolar transistors are adopted, and as the switching elements UL, VL and WL, for example, npn type bipolar transistors are adopted. Excitation signals UHG and ULG output from the inverter 110 are respectively input to the base terminals of the switching elements UH and UL, the excitation signals VHG and VLG are respectively input to the base terminals of the switching elements VH and VL, and the excitation signals WHG and WLG are The signals are input to the base terminals of the switching elements WH and WL, respectively. Each switching element UH to WL is turned on when a corresponding excitation signal is input to the base terminal, and outputs a drive signal to the coil 122. In the above description, a bipolar transistor is used as the switching element. However, other transistors such as a field effect transistor or other switching element may be employed.
[0031]
The comparison unit 130 prevents excessive power supply to the coil 122, and compares the drive signal output from the drive circuit 120 with the upper limit current value stored in the upper limit current storage unit 140 in advance. The upper limit value of the drive current is limited so that the level of the drive signal is equal to or lower than the upper limit current value.
[0032]
FIG. 6 is a timing chart showing the operation of the electric powered wheel apparatus, where (a) shows U, V and W phase pulse signals HU, HV and HW output from the Hall sensor 40, and (b) Excitation signals UHG, ULG, VHG, VLG, WHG and WLG output from the inverter 110 are shown.
[0033]
When driving of the motor 30 is started and the position of one of the rotor magnets 132 is detected by the hall sensor 40, one of the pulse signals HU, HV, and HW corresponding to the detected rotor magnet 132 is output. When the position detection unit 60 receives the pulse signal output from the hall sensor 40, the position detection unit 60 resets the counter, starts counting the pulse signal output from the rotary encoder 21, and outputs the counter value (position information) to the inverter. To 110. The inverter 110 that has received the counter value refers to the memory 1101 and reads an output value (sine wave amplitude) corresponding to the received counter value. Then, the read output value (amplitude of the sine wave) is multiplied by the speed control signal output from the PI control unit 100, and the multiplied value is compared with the triangular wave to generate a pulse signal, and this pulse signal is excited. The signal is output to the drive circuit 120 as a signal. When receiving the excitation signal, the drive circuit 120 turns on the switching element and outputs the drive signal to the coil 122. Then, the coil 122 is excited by this drive signal, a magnetic field is generated between the rotor 13 and the stator 12, and the rotor 13 is rotated by this magnetic field.
[0034]
FIG. 7 is a graph showing the relationship between the rotational speed of the rotary table 2 and the command speed of the electric wheel apparatus, where the vertical axis shows the rotational speed of the rotary table 2 and the horizontal axis shows the command speed. . The origin of the graph corresponds to the case where the depression position of the pedal 3 is at the home position. As the amount of rotation of the pedal 3 by the potter increases, the level of the command speed increases and the turntable 2 accordingly. It can be seen that the rotation speed increases. When the potter returns the depressed position of the pedal 3 to the home position and the level of the command speed becomes equal to or lower than the first threshold value A1, the command speed determination unit 80 rotates the turntable 2 with respect to the inverter 110. The speed is 0, and the rotation table 2 cannot be manually rotated (in a free state) is instructed. Thereby, the rotary table 2 will be in a locked state.
[0035]
Next, when the potter returns the depressed position of the pedal 3 to the home position further, and the level of the command speed becomes equal to or less than the second threshold value A2, the command speed judgment unit 80 The inverter 110 is instructed to stop the excitation to the motor 30. Thereby, the excitation to the motor 30 is stopped, the rotary table 2 is in a rotation free state, and the rotary table 2 can be manually rotated.
[0036]
Thus, according to this electric powered wheel apparatus, the rotary table 2 cannot be rotated unless the pedal is depressed to some extent and the command speed level is set to be equal to or higher than the first threshold value A1, so that the locked state is stabilized. Can be sustained. As a result, rotation of the rotary table is prevented by the potter's intention, and damage to the pottery can be prevented.
[0037]
Further, from the locked state, the position where the pedal 3 is further depressed is returned to the home position, and unless the command speed level is set to the second threshold A2 or less, the rotary table 2 does not enter the rotation free state. The depression range of the pedal 3 for sustaining is widened, and therefore the locked state can be stably maintained.
[0038]
Further, when the command speed level becomes equal to or lower than the first threshold value A1, the lock state is entered. When the command speed level becomes equal to or less than the second threshold value A2, the rotation becomes free. The free state can be adjusted in stages.
[0039]
In addition, the electric potter's wheel apparatus which concerns on this invention may make the rotary table 2 into a locked state or a rotation free state as shown below.
[0040]
In the said embodiment, although 1st and 2nd threshold value A1 and A2 were provided, it is not limited to this, Only 1st threshold value A1 is employ | adopted and the level of instruction | command speed became below 1st threshold value A1 Sometimes, the excitation to the motor 30 may be stopped to make the rotation free state. In this case, the rotary table 2 is brought into the rotation free state without going through the locked state.
[0041]
Furthermore, drive control to the motor 30 may be performed so that the command speed and the rotation speed of the rotary table have the relationship shown in the graph of FIG. In the graph of FIG. 8, the vertical axis indicates the rotation speed of the rotary table, and the horizontal axis indicates the command speed. When the command speed level increases, when the level becomes equal to or higher than the first threshold value A1, excitation to the motor is started and the turntable 2 is rotated. On the other hand, when the level of the command speed decreases, when the level becomes equal to or lower than the first threshold value A1, the command speed determination unit 80 causes the rotation speed of the turntable 2 to become zero with respect to the inverter 110. Instructs to output a simple excitation signal and sets the lock state. Further, when the command speed level becomes equal to or lower than the second threshold value A2, the command speed determination unit 80 instructs the inverter 110 to stop the excitation to the motor 30, and the rotation table 2 is in a rotation free state. To. In this way, by providing hysteresis in the relationship between the command speed and the rotation speed of the rotary table, chattering caused by the foot placed on the pedal 3 fluctuating can be suppressed, and the locked state can be stabilized. Can be maintained.
[0042]
Next, the setting of the output voltage at the upper and lower limit positions of the pedal will be described. The lower limit value of the voltage output from the pedal 3 (the voltage value when the pedal is positioned at the home position) is a case where an appropriate rotation speed cannot be obtained according to the pedal position due to a problem of mechanical mounting accuracy. There is. FIG. 9 is a graph showing the relationship between the voltage signal output from the pedal 3 and the rotation speed of the rotary table 2 with respect to the pedal position, and L3 represents the voltage signal output from the pedal 3 before correction. L4 indicates a preferable voltage signal output from the pedal 3. L1 and L2 are graphs showing the relationship between the rotational speed of the turntable 2 and the depression position of the pedal 3, and L1 corresponds to L3 and L2 corresponds to L4.
[0043]
As indicated by L3, the voltage signal output from the pedal 3 deviates from the preferred voltage signal L4, so that the rotation speed of the turntable 2 changes as indicated by L1, and at the desired pedal position. The rotary table 2 cannot be locked.
[0044]
Therefore, in the electric powered wheel apparatus, by connecting an output voltage correction unit to the speed setting unit 70, the relationship between the voltage signal output from the pedal 3 and the depression position of the pedal 3 is a straight line indicated by L4. By correcting, the rotary table 2 can be locked at a desired pedal position.
[0045]
The output voltage correction unit includes a memory that stores a voltage value when the pedal measured in advance is in the home position when the apparatus is shipped. When a voltage signal is output from the pedal 3, the voltage value stored in the memory is subtracted or added from the voltage signal and output to the speed setting unit 70. Thereby, the voltage signal output from the pedal 3 is corrected as L4. As a result, the rotary table 2 can be locked at a desired pedal depression position.
[0046]
The electric powered wheel apparatus according to the present invention may take the following aspects.
[0047]
(1) Although the DD motor is employed as the motor 30 in the above embodiment, the present invention is not limited to this, and a motor other than the DD motor may be used.
[0048]
(2) Although the inner type motor is used in the above embodiment, the present invention is not limited to this, and an outer type motor may be employed.
[0049]
(3) In the above embodiment, the speed control signal is generated using the subtractor 90 and the PI controller 100. However, the present invention is not limited to this, and a PLL circuit is connected instead of the subtractor 90 and the PI controller 100. May be. By connecting a PLL (phase lock loop) circuit, speed stability is further improved, so that speed unevenness can be reduced, and it becomes easy to make a ceramic dish such as a platter that requires low-speed rotation.
[0050]
(4) In the above embodiment, the speed detection unit 50 generates the speed signal from the pulse signal output from the rotary encoder 21, but is not limited thereto, and the speed signal is generated from the pulse signal output from the Hall sensor 40. It may be generated.
[0051]
(5) In the above embodiment, the inverter 110 outputs a sine wave signal, but is not limited thereto, and may output a pulse signal.
[0052]
(6) In the above embodiment, the PI control unit 100 is configured by the proportional unit 101 and the integrating unit 102, but is not limited thereto, and is configured by only one of the proportional unit 101 and the integrating unit 102. May be. Further, a differential unit may be further connected to the proportional unit 101 and the integrating unit 102, and a speed control signal may be generated by PID control.
[0053]
(7) In the above embodiment, the command speed determination unit 80 sets the value of the command speed based on a function that increases linearly as the level of the voltage signal output from the pedal 3 increases. However, the present invention is not limited to this. For example, as shown in FIG. 10, the command is based on a function whose value increases exponentially as the level of the voltage signal output from the pedal 3 increases. A speed value may be set. Furthermore, as shown in FIG. 11, in the region where the level of the voltage signal output from the pedal 3 is low, the value rises in a slow curve, and in the region where the level of the voltage signal is intermediate, the value increases. The command speed value may be set on the basis of a function in which the value changes substantially flat and the value of the voltage signal is high in a region where the value rises substantially linearly. Thereby, the depression position of the pedal and the rotation speed of the turntable 2 with respect to the depression position coincide with the feel of the potter, and the operability can be improved. Moreover, you may comprise so that any one graph can be selected from the graph shown in FIG.4, FIG.10 and FIG.11 according to a potter's liking.
[0054]
【The invention's effect】
As described above, according to the electric powered wheel apparatus according to the present invention, the rotation-free state can be stably maintained. Therefore, the rotation table can be stably placed in the locked state or the rotation-free state without a timer. Can be maintained.
[Brief description of the drawings]
FIG. 1 shows an external view of an electric wheel apparatus according to the present embodiment.
FIG. 2 shows a sectional view of the electric powered wheel apparatus.
FIG. 3 shows a block diagram of the main part of the electric powered wheel apparatus.
FIG. 4 is a graph showing a relationship between a voltage signal output from a pedal and a command speed.
FIG. 5 is a circuit configuration diagram of a drive circuit.
FIG. 6 is a timing chart showing the operation of the electric powered wheel apparatus.
FIG. 7 is a graph showing the relationship between the rotation speed of the rotary table and the command speed.
FIG. 8 is a graph showing a relationship between a rotation speed and a command speed of a rotary table according to a modification.
FIG. 9 is a diagram for explaining how the offset voltage is corrected to 0;
FIG. 10 is a graph showing a relationship between a voltage signal output from the pedal 3 and a command speed.
FIG. 11 is a graph showing a relationship between a voltage signal output from the pedal 3 and a command speed.
FIG. 12 is a graph showing the relationship between the rotation position of the pedal and the rotation speed of the rotary table of the conventional electric wheel apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing 2 Rotary table 3 Pedal 4 Lever 6 Stopper 7 Power cable 21 Rotary encoder 12 Stator 13 Rotor 14 Motor shaft 30 Motor 40 Hall sensor 50 Speed detection part 60 Position detection part 90 Subtraction part 100 PI control part 101 Proportional part 102 Integration part 103 Adder 110 Inverter 120 Drive circuit 130 Comparison unit

Claims (2)

A rotary table that rotates on a horizontal surface that is exposed and rotatable at the upper part of the apparatus main body, a motor that rotates the rotary table, and a motor that is connected to the outside of the apparatus main body and can be stepped on by an operator's feet. A pedal and drive control means for driving the motor at a speed corresponding to the depression level;
When the stepping level becomes equal to or lower than a first threshold, the drive control means sets the rotary table in a locked state and further reduces the stepping level to a second threshold that is smaller than the first threshold. An electric wheel apparatus characterized in that the rotary table is brought into a rotation-free state when the following occurs. A rotary table that rotates on a horizontal surface that is exposed and rotatable at the upper part of the apparatus main body, a motor that rotates the rotary table, and a motor that is connected to the outside of the apparatus main body and can be stepped on by an operator's feet. A pedal and drive control means for driving the motor at a speed corresponding to the depression level;
The drive control means rotates the rotary table when the pedal depression level rises above a first threshold, and when the pedal depression level falls, the drive level is reduced to the first level. The rotating table is set in a locked state when the threshold value is less than or equal to the threshold value, and the rotating table is set in a rotation-free state when the level becomes equal to or lower than a second threshold value that is smaller than the first threshold value. Ironing device.

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