JPS62161507A - Electric lathe for ceramic art - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field 1 The present invention relates to an electric potter's wheel for pottery.

[Background technique HjJ The conventional electric potter's wheel for pottery of this type is
There was something like that seen in Publication No. 14992. However, as shown in FIG. 12, in this conventional example, the outside diameter of the main body (1) was larger than the diameter of the rotary table 2, and the shape was box-shaped, so the worker's knees hit the main body housing 1 during work. Therefore, spread the left and right feet A and B at a large angle α1 as shown in the diagram to make the knee width about 400~
(b) Therefore, it was impossible to freely select the knee width suitable for the work content and the individual, resulting in poor work efficiency. Furthermore, since the body housing 1 has a rectangular parallelepiped shape, the writing position is inevitably determined, and the operating position of the switch, speed adjustment pedal 23, lever 18, etc. is also in a state where the working posture is disturbed.

Furthermore, due to the shape of the main body housing 1, clay during processing tends to accumulate on the main body housing 1, making cleaning, cleaning, etc. very time-consuming.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and its purpose is to provide an electric potter's wheel for pottery that can be used more easily during main work and auxiliary work in potter's wheel work. It is on offer.

1 Disclosure of the Invention 1 The present invention comprises a rotary table; 1 a main body housing housing a DC motor for driving the rotary table; It is characterized by having a substantially conical shape, and is an improvement on the usability problems of electric pottery wheels.

This will be explained below using examples.

L! uL Main body housing 1 is molded using the blow molding process to reduce weight and make it easier to carry.It forms the necessary unevenness during molding, making it easy to create a free design. Remove and save time when cleaning.
Furthermore, by coloring the resin, there is no need to worry about painting, and as shown in FIGS. As shown in the figure, a recess 6 is formed on the side of the hem to serve as a space for attaching a power switch 4, etc., and as a handhold during carrying.

Further, inside the main body housing 1, drive mechanisms such as a DC motor 14 for driving the rotary table 2 and a control are housed. The rotary table 2 is attached to the upper end of the rotary table pongee 7 which penetrates inwardly and outwardly from the central base surface of the main body housing 1, and is rotatably supported above the base surface of the main body housing 1, and its diameter is equal to that of the main body housing 1. The outside diameter is larger than the outer diameter of the part above the hem part of 1, and forms a space C below the rotary table 2 in which the worker's knees can fit, and the left and right legs A and B can be expanded as shown in Fig. 5. It is also possible to narrow the knee width dimension by making the angle a2 smaller than the conventional α, and therefore it is possible to select a knee width suitable for the work content and the worker. The rotary table Tsumugi 7 is supported by an upper substrate 9 via a bearing 8, and its lower end is connected to a gear box 1 via a clutch 10 shown in FIG.
It is connected to the output shaft 12 of 1. The gear box 11 is attached to a central board 24 disposed inside the center of the main body housing 1 together with a DC motor 14 and a controller 13. Power transmission between the DC motor 14 and the gear box 11 is via a belt 15 and a pulley. It is done at 16, 16'.

The lower board 17, which resembles a bottom cover that opens the bottom opening of the main body housing 1, is a pedal shaft 1 that has two stirring functions: turning on/off the clutch 10 and controlling the rotation speed of the DC motor 14.
9, a speed adjustment beg 23 and a lever 18 are coaxially fixed to one end of this pedal shaft 19 protruding outside the main body housing 1, and the other end of the pedal shaft 19 inside the main body housing 1 is fixed. A clutch operation pin 20 and a motor speed control lever 21 are provided. The clutch stirring pin 20 is connected to a wire (not shown) for fabricating the clutch 10, and the motor speed control lever 21 is connected to a variable resistor 22 for adjusting the DC motor speed.
In the latter, the clutch 10 is turned on and off in conjunction with the rotation of the pedal shaft 19, and in the latter, the resistance value of the variable resistor 22 is changed according to the rotation angle of the pedal shaft 15). The speed adjustment pebble 23 has a conventional shape @Figure 6 (a)
As shown in Fig. 6(b), it is narrow in width, while it is formed in an approximately inverted I shape as shown in Fig. 6(b), with the toe of the foot facing outward as a natural foot posture. Key i/X rTT
It is placed on top of the peg 23, and eliminates the need to move the toe of the foot inward every time the gear is changed.

The upper substrate 9 and the center substrate 24 are supported and fixed on the lower substrate 17 by three support columns 25.

The controller 13 is for controlling the DC motor 14, which is used to generate high torque, and employs a circuit using a Leonard type circuit using a thyristor or a pulse width modulation type circuit using a DC chip circuit, for example, to control a low speed motor 14. Sufficient high torque is obtained at various times, and the rotational speed is stabilized against fluctuations in torque, making each work element easier.

FIG. 7 shows the circuit configuration in the case of the Leonard system, in which the thyristor 26 is connected to the thyristor 1. commercial power supply 27
A DC motor 14 is connected to the variable resistor 2 for speed adjustment.
The trigger generated by the ignition control circuit 28 according to the resistance value set by 2 changes the generation phase of the pulse, varies the conduction angle of the thyristor 26, and adjusts the rotational speed of the DC motor 14. . The resistance value of the variable resistor 22 can be adjusted by adjusting the speed 14-node beta 23 or the lever 18 to control the beta shaft 19 and the motor speed control lever 2.
It can be changed via 1. Figure 8(a)-(e)
2 shows the waveforms of each part of the same as above, in which (a) shows the input waveform at point a of the thyristor 26, (b) shows the input waveform at point b of the thyristor 26, and (c) shows the input waveform at point b of the thyristor 26. Output waveform at point C of thyristor 2G, the same figure (d) shows variable resistor 22
The trigger pulse waveform at point b when the speed is adjusted by , and (e) in the same figure shows the output waveform at point C at that time. Nao 29
is a rectifier, and 30 is a constant voltage circuit.

According to the present Leonard system, the speed-torque characteristic shown in FIG. 9 shows that the torque in the high speed range is low and the torque in the low speed range is high, as shown by curve A. The curved line in the figure shows a conventional case in which a mechanical mechanism such as a ring cone continuously variable transmission is used for the ink-gushing motor.In the case of this conventional example, there is some torque in the high speed range, but in the low speed range. It can be seen that the torque is low and the torque at low speeds is insufficient compared to the present method, making it unsuitable for molding large objects such as platters.

Next, a pulse width modulation method using a DC chopper circuit will be explained with reference to the circuit configuration diagram in FIG. 10 and the time chart in FIG. 11. When the power is turned on now, the capacitor CR is charged with a time constant determined by the resistor R1 and the capacitor cpts. A comparator 35 of the starting circuit 34 compares the charging voltage with the voltage determined by the resistors R2, R3, and R.
A sample pulse is generated by the output of the start-up circuit 34 when the terminal voltage at terminal R3 is lower than the terminal voltage at terminal SB. Therefore, the output voltage of the sample hold circuit 36 becomes the same voltage as the sawtooth wave voltage of the sawtooth wave generation circuit 37,
When the capacitor CT is charged, the output of the sample and hold circuit 36 becomes high, and the output of the comparator 13 becomes H.
level, and the power MO8FE is output via the output circuit 41.
T38 data) frt is output and DC motor 14
starts. If there is chattering of the switch when the power is turned on, the power supply voltage may be lower than that of the DC motor 1 even if a starting pulse is generated.
4, the DC motor 14 does not start.

Therefore, the comparator 40 of the startup time reset circuit 39
The reference voltage in the circuit and ? I! Compare the source voltage voltage Vce with the voltage divided by R6 and R7, and if the power source voltage has fallen below the set voltage due to chattering or other causes,
6. The capacitor CR5 for setting the start-up time is discharged through the transistor Q, and a sample pulse for the required start-up time is generated when the power supply voltage is stabilized at the set voltage. Therefore, when the power switch is turned on, the DC motor 14 starts smoothly without overshooting the set rotation speed. Moreover, even if the switch chattering or the switch is repeatedly turned on and off, the DC motor 14 will start smoothly from the set rotation speed.

When the DC motor 14 is activated and starts rotating, the speed signal shown in FIG. 11(a) proportional to the number of rotations is input to the hysteresis comparator OP2, and as shown in FIG. 11(IJ), the speed signal proportional to the number of rotations is generated. Obtain a square wave pulse of .

This square wave causes the sample/reset pulse generation circuit 3 to
A trapezoidal wave circuit 33 generates a trapezoidal wave as shown in FIG. 11(e). The rise of this trapezoidal wave is converted into a reference voltage V + -V 2- V from a reference voltage generation circuit (not shown).
11 (6)), sample pulse (first
1(e)) and the timing at which the reset pulse (FIG. 11(d)) is generated are determined. On the other hand, in the sawtooth wave generating circuit 37, the capacitor C, is charged by the constant current source 2, and the charge stored in the capacitor C, is discharged when the reset pulse is generated, as shown in FIG. , generates a sawtooth wave as shown in the same figure.Sample and hold circuit 3
6, when a sample pulse is generated, the sawtooth wave voltage at that time is sampled and held by charging or discharging the hold capacitor C11. Therefore, a DC signal (No. 8) proportional to the rotational speed is outputted to the sample and hold circuit 36 as shown in FIG. 11(g).

And speed 1! ! Voltage set with variable resistor 22
The difference between × and the output voltage of the sample and hold circuit 36 is inverted and amplified by an error amplifier, and the output is compared with a reference triangular wave by a comparator 35 as shown in FIG.
A square wave is obtained as shown in Figure 511 (i). This square wave is output through the output circuit 41 to obtain a date voltage as shown in FIG. 11(j), and the power MO8FET3B is
The power supply to the DC motor 14 is controlled by PWM.

The lock insurance circuit 42 has the following functions. That is, when an overload is applied to the DC motor 14, the rotation speed of the DC motor 14 decreases. Therefore, the speed detection circuit 31
The output frequency of the sample and hold circuit 36 becomes smaller.
output voltage increases.

The voltage is detected, and when the rotation speed falls below a set value, the output pulse is cut off and the DC motor 14 is stopped.

By the way, when the output of the hysteresis converter OP2, which manually inputs the detection signal from the speed detection circuit 31 which outputs No. 43 shown in FIG. At 32, the transistor Q2 is turned off, so the transistor Q is turned on.

The transistors Q, , Q, are driven with constant current.

Therefore, the charge in the capacitor CR of the trapezoidal wave circuit 33 is discharged by the transistor Q at a constant current. As described above, since the discharge current of the capacitor CR is a constant current and the current flowing to the ground is not an instantaneous large current, no spike pulse is generated as shown in FIG. 11(g).

But such a P W M till I! According to the speed-torque characteristic shown in FIG. 9, as shown by curve C, there is a slight torque in the high speed range, and high torque in the medium to low speed range.

[Effect of the Invention J] The present invention comprises a rotary table and a main body housing housing a motor for driving the rotary table, and the outer diameter of the main body housing is made smaller than the diameter of the rotary table, and the outer shape of the main body housing is omitted. Since it is shaped like a cone, it can be placed below the rotary table! This creates a space for the worker's knee to be inserted, allowing the user to freely select the knee width that suits the work content and the individual.As a result, there are no restrictions on working posture, making work easier. This has the advantage that it can be used from any direction.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention seen from the side, fjS
Figure Z is a cross-sectional view of the same as seen from the front, Figure 3 is an explanatory view of the same main parts with some parts omitted and broken away, and Figure 4 is an enlarged cross-sectional view of the clutch of [a Tohi with some parts omitted and broken away. Figure 5 is an explanatory diagram of the use seen from the top of the same as above, Figure 6 (b) is a comparative explanatory diagram of the speed adjustment pedal of the same as above, Figure tpJ7 is a circuit configuration diagram of the Leonard control system used in the same as above, Figure m8 is PtS7.
Figure 5 is a waveform diagram for explaining the operation of the circuit.
Torque characteristic comparison explanatory diagram, 1st () and I are P used as above
WM control system circuit configuration diagram, fpJ11 diagram @ 10
Figure 1 is a waveform diagram for explaining the operation of the circuit, 12th page 1 is an explanatory diagram as seen from the top of the conventional example, 1 is the main body, 2
The rotary table 171 is a jQ flow motor. Representative J11j Patent Attorney Ishi 111 Ai Figure 3
(Figure 4, Figure 1, Figure 5, Figure 6, CG) (b) Figure 11, Figure 12

Claims (1)

[Claims] (1) A rotary table and a main body housing housing a motor for driving the rotary table are provided, the diameter of the outer periphery of the main body housing is made smaller than the diameter of the rotary table, and the outer shape of the main body housing is formed into a substantially conical shape. An electric potter's wheel for pottery.