JPS60148587A - Electromagnetical yarn tension imparting apparatus in sewingmachine - 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) The present invention relates to a thread tensioning device for a sewing machine.

(Prior art) There are two types of thread tension devices for sewing machines: a regular type that presses the thread between thread tension discs and applies tension through frictional resistance between the thread and the thread tension disc, and a radial spoke of a rotating spinning wheel. There is a method in which a thread is bent and wound between the parts, and when the thread is pulled, a spinning wheel is rotated, and the control is controlled by pressing felt or the like against the side of the spinning wheel. As for automation, in the former case, the clamping force of the thread tension plate is reduced to 1! There are methods of adjusting the thread tension using a solenoid or turning the thread tension knob using a motor, but these methods are difficult to make delicate adjustments, and there is also the problem of damage to the thread due to friction with the thread tension disc. In addition, in the latter case, there is a problem that the spinning wheel rotates inertia more than necessary, so it is not practical except for special sewing machines.
However, there are not many proposals for its automation.

(Object and Solution) The present invention provides easy fine adjustment through electrical control.
The object of the present invention is to provide a thread tension device suitable for automation, which uses a rotary spinning wheel and is connected to an electric control device to electrically control its braking force to adjust the thread tension.
This solves the problem of inertial rotation of the spinning wheel, and also enables automatic and highly accurate adjustment of electrical control using a microcomputer or the like as required.

(!ii! Examples) Examples of the present invention will be described below based on the drawings. In FIG. 1, the spinning wheel +11 has arc-shaped spoke portions (3) disposed radially on each spinning wheel body (2) (2).
3> are engaged with each other, and the upper thread (not shown) is received in the engaged portion (4), and the upper thread (5) is let out from the bobbin winder (6) as shown in FIG. Thread take-up spring (7
), the needle (8) pierces the fabric (not shown) K, and the thread take-up (9) moves the upper thread (5) to the spinning wheel (1). When it passes, it rotates according to the amount of movement.

As shown in Fig. 3, the stator α of the braking device a0 has one field core α consisting of, for example, eight poles, six poles each having five teeth α, and an electric coil α◆ wound around the six poles. I am wearing it. rotor 0
υ has iron core OQ of 50 $<1(!) and teeth θj
and teeth aη have the same pitch angle. Therefore, the pole teeth as, a that are mutually symmetrical about the axis Qll
'I) are in a mutually coincident rotational position relationship, the teeth of the other poles are arranged so that their rotational positions are shifted from each other. The spinning wheel (1) is fixed to the shaft Cl11 and rotates at the same time as the rotation preliminary test. Electric coil (1 unit is control power supply circuit (DV)
) is excited by direct current. The tooth of the pole of the stone
3 and tooth 0η are at the same rotational position, the magnetic flux through the air M (11) reaches its maximum, and the rotating spinning wheel T
ll is pulled into this rotational position and becomes stable, and acts as a braking force when exiting from this position.

8g4 is obtained by plotting the maximum value of the control torque T, that is, the braking torque in the stable state, against the excitation current (2) of the electric coil (1, 1), and the braking torque increases as the excitation current increases. Note that this braking torque is generated every time tooth 03 and tooth <17 match, but when the balance (9)
The number of teeth (2), 0η, is set so that this braking torque is always present when the thread line is raised and the thread is fed out.

In the above configuration, when the current I of the electric coil α is adjusted by the control current supply circuit (DV), the braking torque T of the spinning wheel (1) is adjusted, so that the upper thread ( The force for preventing or restricting the unwinding of 5) is adjusted, and during the period of preventing or restricting the unwinding, the yarn is drawn in cooperation with the yarn take-up spring (7).

Figure 5 is a replacement for the brake system shown in Figure 1, and the brake system has the same structure as the PM type pulse motor, with a stator? The mutually meshing tooth poles of the rim are alternately turned into N and S poles by direct current excitation of the electric coil.
A multi-pole structure is formed on the circumference facing the rotor ψ9 with a gap (c) interposed therebetween. The tooth pole (c) and the electric coil wire have the same structure, and the tooth pole (c) is fLIII.
Intermediate position between N pole and 8 pole by t pole (2) The rotor 0 has a spinning wheel (1) fixed to its axis tri, and the N pole and 8 pole are alternately arranged on the circumference of the magnet (c). It consists of

The excitation current is similarly controlled by the control current supply circuit (DV) in Fig. 2. Fig. 6 shows yet another embodiment of the braking device, in which the braking device) is connected to its rotor (T). The stator (31) is composed of a magnet, and the stator (31) includes an excitation coil (32) that is excited by a DC power supply (CE), and a secondary coil (33) that generates an electromotive force by the rotation of the rotor α. The rusting pressure of the secondary coil (33) is adjusted by a variable resistor (R). The excitation coil (32) produced a braking torque similar to that shown in Figure 1 or Figure 5, and the secondary coil (33) was designed to perform electrical braking to absorb the inertial force of the spinning wheel (1). It is something. The DC power supply (IE) and the variable resistor (R) are electrically controlled externally by a control circuit similar to the control current supply circuit (DV) shown in FIG.

Figure 7 is a control block diagram, and the read-only memory device (ROM) is used to store sewing machine motor (8M) speed control signals, braking device output signals, excitation current signals (e), and program control signals. I remember things like that. The central processing unit (CPU) is a read-only storage device (ROM),
In cooperation with temporary memory (RAM), input/output capo)
(Ilo), the speed of the sewing machine motor (SM) is controlled via the speed control device (CONT), the speed detector (8D) detects the speed, and the central processing unit (CPU) adjusts the speed to that speed. Accordingly, the excitation current by the control current supply circuit (DV) is controlled. External adjustment device! (VR) is a spinning wheel (1)
The central processing unit (CPU) similarly controls the excitation current according to the adjustment.

(Effects) As described above, according to the present invention, since the thread adjustment is electrically controlled, fine adjustment is possible, and since the rotation of the spinning wheel is braked from time to time, the problem of inertia is also solved. It is also possible to automatically adjust n1 using a microcomputer or the like as shown in FIG. 7, if necessary.

[Brief explanation of drawings]

Fig. 1 is an overall structural diagram of a spinning wheel and a braking device showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of a thread tension system, Fig. 3 is a sectional view in the direction of Fig. FIG. 5 is a characteristic diagram of braking torque with respect to excitation current, FIGS. 5 and 6 are diagrams of other embodiments of the braking device, and FIG. 7 is a control block diagram. In the diagram, (1) is the spinning wheel, 011 (c) 0 is the stator, and 05
Light 9 (to) is a rotor, and (Dv) is a control current supply circuit. Special Applicant: Janome Sewing Machine Industry Co., Ltd. Inventor: Riki 11 Ken Fuji, Hara - Authorized Patent Attorney: Sho Yoshihara, Sho Sando, Takashi Takashi, Benyu Hiroshi Yoshi Zen, Disciple 1 Diagram ■ Figure 3

Claims (1)

[Claims] A stator in which one or more electric coils are wound around a field core, a rotor that generates braking force by receiving magnetic flux from the stator through an air gap, and a thread supply path for the sewing machine. a spinning wheel that rotates integrally with the rotor against the braking force as the yarn moves, and a control current supply that supplies a control current for braking force adjustment to at least one of the electric coils; An electromagnetic thread tensioning device for a sewing machine comprising a circuit.