JPS5938324B2 - How to operate a spinning machine using a DC motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spinning machine such as a spinning machine, a yarn twisting machine, a drawing and twisting machine, etc.
In particular, it relates to a method of operating these spinning machines using a DC motor.

Conventionally, spinning machines and the like that require variable speed operation have used a DC motor as a drive source because the rotation speed can be easily changed, and the rotation of this DC motor has been controlled by changing the field voltage.

This DC motor requires a small installation space, and in order to achieve good transmission efficiency, the DC motor directly drives the driving shaft through a coupling, and transmits rotation to the spindle through a driving pulley and spindle warp. was.

Therefore, the ratio between the rotational speed of the DC motor and the spindle rotational speed is always set to a constant value, and the spindle rotational speed is changed in accordance with the speed change of the DC motor.

Note that the rotational speed N of the DC motor is determined by the equation of proportionality constant V: armature voltage ra: armature resistance a: armature current φ: field magnetic flux, so increase or decrease the field magnetic flux φ The rotational speed N is changed by increasing or decreasing the armature voltage (2).

Specifically, in a conventional spinning machine, in order to increase or decrease the field magnetic flux φ while keeping the armature voltage constant, the field current If is increased or decreased as shown by I in Fig. 2, and it is directly converted into a direct current. The rotational speed of the electric motor, indirectly the spindle rotational speed, was changed in accordance with the partial pressure as shown by the solid line in FIG.

However, in such a conventional device, as can be seen from the curve I in Fig. 2, even if the field current If is increased, when the field core reaches the saturation region, the copper loss increases due to the current.
It became impossible to substantially reduce the spindle rotation speed.

Therefore, the field current of the DC motor used is I in Figure 2.
Of these, use range A is used to perform variable speed operation as shown by the solid line in FIG.

In addition, the speed change curve for spinning spinning machines differs depending on the yarn count and type used, so in the case of thick yarn, etc., the speed change curve needs to be performed in a lower rotation range than in the case of normal yarn. This has been extremely difficult with spinning machines for the reasons mentioned above.

In short, conventional devices can only be applied to yarns of a certain type and yarn count, and lack versatility.

In order to make it more versatile, it was necessary to replace the DC motor with a low-speed DC motor.

The present invention has been made with a focus on the runner-up points of such conventional devices, and is intended to expand the usable rotational speed range of electric motors such as spinning machines, and to enable the use of different types and thread counts of different yarns. Specifically, in a spinning machine where the ratio between the rotational speed of the DC motor and the rotational speed of the spindle is always set to a constant value, the DC motor should be The armature voltage is changed stepwise and set to a constant value, and after startup, the field current of the DC motor is controlled during operation, and the spindle rotation speed is changed according to the molecule. .

Hereinafter, one embodiment of the present invention applied to a spinning machine will be explained with reference to the drawings. Fig. 1 shows a control circuit diagram of a DC motor used in a spinning machine, and in the figure, B, S, and T are connected to a three-phase power supply. Wiring, Fl, F2. F3 is a fuse inserted in the wiring, Di, D2°D3. D4. D5. D6 is a diode and constitutes a rectifier circuit for converting three-phase alternating current into direct current.

And Fl 1, Fl 2. Fl3, Fl4°Fl5. Fl6 is a fuse inserted into this rectifier circuit.

In addition, (1) is the armature winding connected to the rectifier circuit, (2
) is a field winding connected in series to a separate DC power supply (3), and 4 is a variable resistor connected in series to this field winding 2; By changing the resistance value, the field current is increased or decreased, and the rotational speed of the DC motor is controlled to be changed.

Then, normally, using the range of use (a) in Figure 2, the third
As shown by the solid line in the figure, the spindle rotation speed is controlled depending on the molecule.

This is similar to the conventional device.

The main part of the present invention is that the armature voltage (■) of the above-mentioned relational expression is changed in advance to correspond to the type and yarn count of the yarn used, before starting the DC motor, thereby giving versatility to the spinning machine. That's true.

That is, as shown in n, i, and ■ in FIG. 2, the armature voltage V is each 10% compared to the case of I.

By decreasing it by 20% or 30%, the spindle rotation speed can be decreased without increasing the value of the field current If.

Note that various known means can be used to change the armature voltage.
For example, this can be done by using a thyristor, but there is a problem that the device is complicated and expensive, so a simple and inexpensive method will be described.

That is, this is a method of changing the armature voltage by appropriately removing the fuses described above.

For example, as shown in Figure 4, by removing fuse F11, 83%
can be reduced to

Also, by removing fuse F1, the power can be reduced by 67%.

In Figure 2, X indicates the case where fuse F11 is removed;
As shown by the broken line in the figure, the speed of the spindle can be changed in the low rotation range depending on the molecule.

Although the method of removing the fuse has been described, the armature voltage can be changed easily and at a relatively low cost by using a disconnector or a switch instead of the fuse.

As described above, in a spinning machine in which the ratio between the rotational speed of the DC motor and the rotational speed of the spindle is always set to a constant value, the present invention is capable of adjusting the armature electric motor of the DC motor in accordance with the type of yarn used before starting the spinning machine. is changed stepwise and set to a constant value, and after startup, during operation, the field current of the DC motor is controlled, and the spindle rotation speed is changed according to the molecule, which is a simple and inexpensive method. This method allows the rotational speed of the DC motor to be varied over a wide range, and even when using large yarn counts, the spindle rotational speed can be varied in a low rotational range, making it possible to add versatility to the spinning machine.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Fig. 1 is a control circuit for a DC motor, Fig. 2 is a characteristic diagram showing the relationship between spindle rotation speed and field current, and Fig. 3 is a characteristic diagram showing the relationship between spindle rotation speed and molecule. A speed change curve diagram showing the relationship, and FIG. 4 is a table showing how the armature voltage can be changed by removing the fuse. 1... Armature winding, 2... Field winding,
3...DC power supply, 4...Variable resistor,
D1-D6...Diode, F1-F16...
...Hyuse.

Claims (1)

[Claims] 1. In a spinning machine in which the ratio of the rotational speed of the DC motor to the rotational speed of the spindle is always set to a constant value, the armature voltage of the DC motor is changed in stages according to the type of yarn used before starting. Operation of a spinning machine using a DC motor, characterized in that the field current of the DC motor is set to a constant value after startup and during operation, and the spindle rotational speed is changed according to the partial pressure. Method.