CN2133599Y - Adding speed-controlling device of sewing machine - Google Patents

Abstract

The utility model relates to an additional speed-controlling device of a sewing machine. The structure of the additional speed-controlling device is that a pulse wave generating circuit, a voltage control circuit and a comparison circuit are arranged among a sewing machine motor, a power supply and a foot switch, wherein, the pulse wave generating circuit is used to generate oscillating pulse to adjust and change voltage output by the voltage control circuit and obtain feedback voltage signals which are compared with a reference potential via a comparator, so when the output voltage is beyond a set reference voltage level, the motor stops running to be kept away from damage. The reference potential of the comparator is adjusted synchronously with the output voltage and the power of the voltage control circuit, and namely, the reference potential of the comparator follows the change of the set rotary speed of the motor to be simultaneously adjusted to change.

Description

Adding speed-controlling device of sewing machine

The utility model system is meant especially that relevant for the speed control of Sewing machines a kind of Sewing machines adds the innovative design of formula speed-controlling device.

Known to the skill of just going ahead of the rest, the tradition Sewing machines all adopts fixed carbon resister pedal speed regulator to control as the motor pressure decay rate substantially, yet be easy to generate spark between the contact in this its pedal of fixed carbon resister pedal speed regulator at present, the power consumption height, easily produce high temperature and fault, and speed control is unstable, and the operator must have more skilled skill.

Moreover, the circuit system of the control motor speed of existing Sewing machines speed regulator adopts and exchanges (AC) voltage system control, can't when the slow-speed of revolution, keep stabilized speed, and the transistor internal resistance value that it used is big, not only consumed power produces high temperature, and be not suitable for keeping for a long time conducting, so inefficiency.

In addition, the speed control of existing Sewing machines relies on the foot-operated control of operator sewing speed speed fully, therefore the user must be quite high for the qualification of foot-operated control rate, and all day, sole must change in the differing heights position, and easy tired output is also influenced.When Sewing machines is stung line,, then can cause motor to burn if in time do not pull out power supply again.

In view of this, the main purpose of the utility model is providing a kind of Sewing machines to add the formula speed-controlling device, system is connected to motor of sewing machine with the formula of adding, can control simply and set motor of sewing machine in predetermined rotating speed, make speed control easily, and motor speed is stable, and operating efficiency is improved, and increases the product surcharge.

A time purpose of the utility model is providing a kind of Sewing machines to add the formula speed-controlling device, and its control circuit is oversimplified, and consumed power is low, and uses applicable to existing any Sewing machines.

The another purpose of the utility model is providing a kind of Sewing machines to add the formula speed-controlling device, and motor burns when having holding circuit and stinging line to avoid sewing.

Edge is that the utility model Sewing machines adds the formula speed-controlling device and lies between Sewing machines AC power supplies and the motor power line, is provided with a pulse wave and produces circuit, a voltage control circuit and comparison circuit composition; This pulse wave produces circuit system in order to produce the vibration pulse wave, be used for adjusting and change the size of voltage control circuit institute's output voltage and power and obtain the feedback voltage signal through a comparator and reference potential comparison, be used to when output voltage exceeds the reference voltage level of setting, stopped motor running, in case motor is impaired, and the reference potential of this comparator system adjusts synchronously with the output voltage and the power of this voltage control circuit, promptly sets rotating speed with motor and changes and same time modulation.

About detailed circuit structure, function and the characteristics of the utility model, can be able to abundant understanding by the detailed description of following examples conjunction with figs..

Fig. 1 is the circuit system calcspar that the utility model Sewing machines adds the formula speed-controlling device.

Fig. 2 is the system circuit diagram that the utility model Sewing machines adds the formula speed-controlling device.

At first see also Fig. 1, the utility model is fully examined in design and is cooperated existing sewing to use, therefore with the floor push FC of AC power AC and control motor rotary speed through a circuit board a1, b1, the circuit of c1 contact connection speed control device, contact a1 wherein, b1 is through transformer TR1, connect a pulse wave behind the rectifier BR1 step-down rectifier and produce circuit (10) one voltage control circuits (20) and a comparison circuit (30), the detailed construction of these circuit is in hereinafter explanation.This a1, the c1 contact connects a motor M for about 100V DC voltage through a diode D01 after rectifier BR2 rectification, this motor M other end connects this voltage control circuit (20), and the rotating speed system of this motor M is set and controlled by floor push FC and voltage control circuit (20).

See also Fig. 2 again, the speed-controlling device of the utility model mainly is to produce circuit (10) by a pulse wave, and a voltage control circuit (20) and a comparison circuit (30) are formed.

It is by an oscillating element IC2(MC1455 that this pulse wave produces circuit (10)) cooperation resistance R 11, capacitor C 11, diode D11, D12, D13, elements such as variable resistor VR1-1 and variable resistor VR2.

This voltage control circuit (20) is by a high speed motion transistor T 1(MOSFET) and resistance R 21, R22 forms.

This comparison circuit (30) is by a comparator IC1(M51206) cooperate resistance R 31, R32, R33, capacitor C 31 and variable resistor VR1-2 form.

The circuit operation of the utility model speed-controlling device is described as follows:

It is to export pulse wave signal by the 3rd pin of IC2 that this pulse wave produces circuit (10), this variable resistor VR2 system can control T1(MOSFET in order to the work period (Duty cycle) of adjusting this IC2 the 3rd pin output pulse wave) conducting (ON) or carry the ratio of (OFF) time of ending, its ratio can adjust by 3% to 97%, that is sets institute's output dc voltage and power.This variable resistor VR1-1 and VR1-2 are the doubly-linked variable resistor, in order to change the frequency (about 20KHZ) of IC2 the 3rd pin output pulse wave, can control T1(MOSFFT) conducting and deadline, also can change output pulse wave frequency, and then control motor rotating speed.

What other was illustrated is, for making the sewing operation more smooth and easy, can be in the inner transmission mechanism of Sewing machines a precalculated position be provided with a photoelectricity and detect element or magnetic reed switch, its circuit be connected in this speed-controlling device wait control motor stop operating the time, make sewing locomotive pin when the sewing operation stops, must remaining in top dead-centre or bottom dead centre, in order to the facility of procedure operation.

Therefore, be with commonly using Sewing machines control speed mode main difference part, commonly use motor of sewing machine system and directly utilize fixed carbon resister pedal speed regulator to trample the rotating speed of extent control motor with sole according to above-mentioned speed-controlling device.And the utility model lies in and is provided with a speed-controlling device between motor and AC power supplies and the floor push FC, utilize a variable resistor VR2 in order to set the size of output voltage and power in this speed-controlling device, make motor be maintained at preferable output voltage and power, in addition, utilize a doubly-linked variable resistor to be installed on operation easy operating position, adjustable settings output pulse wave frequency, in order to the rotating speed of setting motor, so the operator can set motor in suitable rotating speed according to the material and the style of want sewing article at any time; The operator still can be by floor push FC control rotating speed, only motor is maintained at the rotating speed that this VR1-1/VR1-2 sets as long as floor floor push then, so the operator is easy to be maintained at the sewing that required setting rotating speed is made stabilized speed, and do not need just to be maintained at certain rotating speed with sole, so can lower the tired of sewing personnel, promote sewing quality and efficient.

In addition, this comparison circuit (30) is the reference data voltage V2 that is set comparator IC1 by variable resistor VR1-2, and obtain the feedback voltage signal by the resistance R 22 of voltage control circuit (20), through resistance R 31, capacitor C 31 input comparator IC1 are voltage V1 as a comparison, when motor M transships, the electric current that flows through the MOSFET T1 of voltage control circuit (20) becomes big, causing the last voltage of R22 rises, comparative voltage V1 also rises, as V1〉during V2, the expression motor overload, the output of this comparator IC1 enters IC2 by the 2nd pin, make its 3rd pin be output as electronegative potential, therefore T1 MOSFET stop conducting shuts down motor, causes motor and burns because of stinging line to avoid Sewing machines.

By the foregoing description explanation as can be known, the utility model Sewing machines adds the formula control device and has the following advantages:

1. need to set the Sewing machines rotating speed with the user, make the sewing velocity-stabilization, control easily.

2. velocity-stabilization during the slow-speed of revolution is controlled easily, and avoids commonly using the situation that the speed-controlling device of Sewing machines generates heat greatly because of the transistor internal resistance.

3. beginner's easy operating, is increased work efficiency at the sewing stay in grade.

4. the composed component of integrated circuit is simple, and making easily, cost is low, fault rate is few.

5. the utility model speed controllable circuit is adopted the circumscribed design, is fit to be installed on existing Sewing machines and uses, and applicability is extensive.

In sum, the utility model Sewing machines adds the formula speed-controlling device and compares with the speed-controlling device of commonly using Sewing machines and have multinomial breakthrough improvement, and meets progressive practicality effect.

Claims (2)

1, a kind of Sewing machines adds the formula speed-controlling device, lies in to be provided with pulse wave generation circuit between a motor of sewing machine and power supply and the floor push, and a voltage control circuit and a comparison circuit is characterized in that:

This pulse wave produces circuit and comprises that an oscillating element is in order to the pulse wave that vibrated by output pin output; One variable resistor connects one of this oscillating element pin, in order to the work period of the output pulse wave of adjusting this oscillating element, and then controls the conducting of one of this voltage control circuit transistor or the ratio of deadline; One of one doubly-linked variable resistor also is connected in one of this oscillating element pin, in order to changing the frequency of this oscillating element output pulse wave, with the conducting and the deadline of the transistor of controlling this voltage control circuit, that is changes the frequency of output pulse wave;

This voltage control circuit comprises a transistor, the one end is connected in series a resistance, the other end is serially connected with motor of sewing machine, utilize this pulse wave to produce the variable resistor adjustment of circuit and must set size by this transistor controls output voltage and power, change its operating frequency by this doubly-linked variable resistor adjustment in addition, to change the rotating speed of setting motor;

Search comparative voltage on this comparison circuit system resistance by voltage control circuit, import a comparator one input, its another input is connected to this doubly-linked variable resistor, change its reference voltage with the adjustment of motor of sewing machine speed, this comparator, is made this oscillating element failure of oscillations and must be stopped revolution by its output output signal during greater than reference voltage in comparative voltage;

This pulse wave of mat produces the variable resistor of circuit and doubly-linked variable resistor and is located at the operator and easily controls the position and can adjust the setting motor according to need and at any time in different rotating speeds.

2, Sewing machines according to claim 1 adds the formula speed-controlling device, it is characterized in that, wherein be can be in the inner transmission mechanism of Sewing machines a precalculated position be provided with one and detect element, the circuit that system is connected in this speed-controlling device control motor of waiting stops operating the time, makes the car pin must remain in top dead-centre or bottom dead centre when stopping.

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