EP0391994B1 - Control device for textile machines - Google Patents

Abstract

A control device (57) for textile machines, in particular dobbies, has two magnet yokes (1, 2) with associated permanent mgnets (3) and electromagnet (4), as well as an appropriately built magnet armature (5, 55) held in the first or second end position by the permanent magnetic flow. When a current control pulse is applied to the electromagnet (4), however, the armature suddenly moves to the opposite end position, where it is again held until the next current control pulse moves it to the other end position. Only a very short current pulse is necessary to make the magnet armature (5, 55) change position. The resulting energy impulse is very intense and allows the holding and switching mechanic elements of dobbies to be directly controlled.

Description

The invention relates to a control device according to the preamble of claim 1.

In modern dobby machines, the weaving pattern is converted into mechanical control commands in the form of electrical signals. The interface between electronics and mechanics should contain as few elements as possible and achieve a long service life at a high switching frequency.
Known control devices (for example French patent FR 81 21 106) use a cam-driven mechanism which guide the solenoid armature to the magnet yoke for the selection YES / NO of the control command, the solenoid having to exert the holding force for the magnet armature which is under spring force. Such control systems contain, in addition to the cam-driven mechanism for the magnet armature movement and the electromagnet tension and / or compression springs, further mechanical elements such as pawls, levers with corresponding sliding surfaces, which are necessary for the mechanical strengthening.
If the electromagnet is to attract the magnet armature for its control function without mechanical help, this magnet must have an appropriate power, it becomes large in terms of construction as well as in electrical dimensions, whereby the switching time is longer due to the large bass of the armature, which impairs the performance of the dobby. The listed mechanical parts are subject to wear, are the cause of noise and vibrations and reduce the trouble-free function over a long period of operation of the dobby.

The invention has for its object to reduce the number of parts necessary for the control of a dobby, to increase the ease of servicing and to achieve smooth running even at high speeds.

This object is achieved according to the invention in that a targeted combination of high-performance permanent magnets and electromagnets and a correspondingly selected magnet armature shape for achieving the necessary work capacity for controlling mechanical switching operations with a minimum of mechanics is used, as described in claim 1. The parts of the word achieved with the invention consist in particular in that with very short electrical control pulses in the magnet coil a change in position of the magnet armature is achieved, a force pulse of high intensity being generated during the change of position of the magnet armature and this force pulse being used for direct control of the dobby and the magnet armature is held in every end position without supplying electrical energy, by utilizing the permanent magnetic flux of the permanent magnets.

• Fig. 1 Steuervorrichtung für Schaftmaschine,
• Fig. 2 Steuervorrichtung mit eingezeichneten dauermagnetischen Fluss,
• Fig. 3 Steuervorrichtung mit eingezeichneten dauermagnetischen Fluss und elektromagnetischen Erregerfluss,
• Fig. 4 Steuervorrichtung mit verschobenen Anker (gegenüber Fig. 2) und eingezeichneten dauermagnetischen Fluss,
• Fig. 5 Steuervorrichtung mit asymmetrisch angeordneten Dauermagnete,
• Fig. 6 Steuervorrichtung mit verstellbaren Anschlägen,
• Fig. 7 Steuervorrichtung mit Kippanker,
• Fig. 8 Steuervorrichtung mit stillstehendem Anker und beweglichen Magnetjoch,
• Fig. 9 Steuervorrichtung mit Spule auf Kippanker.

Exemplary embodiments of the invention are shown in the drawings and are described in more detail below.

• 1 control device for dobby,
• 2 control device with drawn permanent magnetic flux,
• 3 control device with drawn permanent magnetic flux and electromagnetic excitation flux,
• 4 control device with displaced armature (compared to FIG. 2) and drawn permanent magnetic flux,
• 5 control device with asymmetrically arranged permanent magnets,
• 6 control device with adjustable stops,
• 7 control device with tilt anchor,
• 8 control device with stationary armature and movable magnetic yoke,
• Fig. 9 control device with coil on tilt anchor.

One possible application of the control device in a dobby is shown in FIG. 1. In a dobby which is not the opposite of the invention, the stem 20 is pulled into an end position, for example a low compartment, by means of the spring 21. The shaft 20 is connected by pulling cable 22 to the pivotable lever 23, which is pivotable Balance 24 carries, at the opposite ends of which a pivotable hook 25, 26 is arranged. A rocker 27 pivoting synchronously with the weaving machine cycle moves the balance 24 with the hooks 25, 26 into the area of the holding hooks 55, 56 of the control device 57. If the shaft 20 has to be brought from the low position to the high position according to the pattern, the holding hook 56 will be triggered by a control pulse led from the electronic pattern control by means of the control device 57 to the hook 26, whereby a positive connection to the fixed control device 57 is created. The rocker 27 now pivots into the other basic position, the holding hook 56 holding the hook 25 in place, while the hook 26 is pushed against the holding hook 55 by the rocker 27. The lever 23 undergoes a pivoting movement and pulls the shaft 20 into the upright position by means of the pull cable 22. If the shaft 20 has to go back into the deep compartment according to the pattern, the holding hook 55 does not change its position, the hook 26 is not held. If the shaft 20 must remain in the high compartment according to the pattern, the holding hook 5 is guided to the hook 26, as a result of which a form-fitting advertising connection to the fixed control device 57 is created.

The basic mode of operation of the control device can be seen from FIGS. 2 to 4. In a bistable magnet system consisting of the magnet yokes 1 and 2, the coil 4 and the polarized permanent magnets 3, a movable armature 5 is formed such that it is simultaneously applied to the pole shoe surfaces P₁ and P₂₂, so that the permanent magnetic flux Φ _M the armature 5 in this Holds position.
If a change in position of the armature 5 is demanded in terms of control, a current-directed control pulse is conducted into the coil 4 which generates an electromagnetic excitation flux Φ _E in the armature 5 which is opposite to the permanent magnetic flux Φ _M (FIG. 3). At the pole shoe surfaces P₁ and P₂₂ the flow difference Φ _M -Φ _E arises while at the pole shoe surfaces P₁₁ and P₂ the flow Φ _M remains (Fig. 3). This larger flow Φ _M compared to flow Φ _M -Φ _E brings the armature 5 from the stable contact position with P₁, P₂₂ in the stable contact position P₁₁, P₂ (Fig. 4). The anchor 5 remains on the pole shoes P₁₁, P₂ stick through the permanent magnetic flux Φ _M , without a current having to flow in the coil 4.
If a change in position of the armature 5 is again required for control purposes in the subsequent machine cycle, a current-directed control pulse is conducted into the coil 4, which generates an electromagnetic flux Φ _E in the coil 4 which is directed in the opposite direction to the permanent magnetic flux Φ _M , whereupon the state shown in FIG. 2 reappears.

It is possible to influence the switching behavior of the control device by means of adjustable stops 6, 7 as shown in Figure 6, the anchor end position to the pole shoe surfaces P₁, P₂₂ and P₁₁, P₂ is changed. A larger distance D₁ and D₂ of the armature 5 from the pole shoe surfaces P₁, P₂₂ and P₂, P₁₁ causes a shorter movement time of the armature 5 from one end position to the other at the same current in the coil 4.

It can be advantageous to design the anchor in form and function as a tilt anchor 50. In the embodiment shown in FIG. 7, the tilt armature 50 is supported in the coil former 56 with the pivot point 51.

Another pivot position for the tilt armature 52 is shown in FIG. 9 where the pivot point 54 is arranged in a magnetic yoke 57. The toggle anchor can be designed to simplify functional processes outside the control device, for example as a holding hook 55, FIGS. 1 and 7.

For certain applications of the control device, it can be advantageous if the tilt armature 52 is fixed in the coil former 53 and the coil former 53 pivots with the anchor 52 FIG. 9.

FIG. 8 shows an embodiment where the armature 45 and the coil 44 are fixed and the magnet yokes 42, 43 carry out the control movement, which can be transmitted to other elements by the toothed segment 41, for example.

By arranging the permanent magnets 33, 34 with one-sided air gap L₁ and L₂ relative to the coupling surfaces K₁₁, and K₂ one achieves a monostable switching behavior of the control device, as shown in Figure 5. The armature 5 is pulled in the de-energized state of the coil 4 to the pole shoe surfaces P₁, P₂₂. If an electromagnetic excitation flow is generated in the armature 5 which is opposite to the permanent magnetic flux, the armature 5 moves to the pole shoe surfaces P 1, P 2 and remains in this position until the current is switched off from the coil, whereupon the armature 5 returns to its starting position with Contact at the pole shoe surfaces P₁, P₂₂. This automatic resetting of the armature 5 without spring force and holding it in the starting position by the permanent magnetic forces can lead to great advantages in the functional sequence as well as simple solutions in the electronic control.

Claims (7)

1. A control device for a textile machine, specifically a dobby, consisting of a first magnet yoke (1) and a second magnet yoke (2) with pole face surfaces P₁P₂P₁₁P₂₂ and permanent magnets (3) polarized in a predetermined direction located therebetween, characterized in that the permanent magnets (3) are oriented with their respective magnet poles so that the same pole polarity of each magnet is facing the coupling surfaces K₁K₁₁ of the magnet yoke (1) and K₂K₂₂ of the magnet yoke (2) and in that one or several electromagnet coils (4) with reversable polarity enclose between the magnet yokes an armature (5,50) moveable between two end positions, and in that the armature (5,50) is designed such that it is kept at the pole face surfaces P₁ and P₂₂ by the permanent magnet flux Φ_M in an end position until a current directed control impulse in the coil (4) produces an electromagnetic excitation flux Φ_E in the armature (5,50) which is oriented oppositely to the permanent magnet flux Φ_M and accordingly produces the flux difference Φ_M- Φ_E at the pole face surfaces P₁ and P₂₂, while the flux Φ_M remains at the pole face surfaces P₁₁P₂, such that due to the larger flux Φ_M in comparison with Φ_M- Φ_E the armature (5,50) is brought from the stable contact position with P₁ and P₂₂ into the stable contact position with P₁₁ and P₂, thus possessing a bistable switching behaviour, and in that the movement of the armature (5,50) and the holding forces between P₁P₂₂P₁₁ can be utilized, by a corresponding design of the armature (5,50) inside or outside of the control device, for a controlling of mechanical operations.
2. Control device according to claim 1, characterized in that the permanent magnet (33) lies on the coupling surface K₁ at the magnet yoke (1) and has an air gap L₁ to the magnet yoke (2), the permanent magnet (34) lying on the coupling surface K₂₂ at the magnet yoke (2) and having an air gap L₂ to the coupling surface K₁₁ at the magnet yoke (1), the permanent magnet flux at the position of the armature (5) with contact at the pole face surfaces P₁P₂₂ producing a high adherance force armature-yoke and producing at the position of the armature (5) with contact at the pole face surfaces P₁₁P₂ a low adherance force armature-yoke, and in that the armature (5) remains permanently at the position with the high adherance force and upon a switching on of a coil current in the coil (4) an electromagnetic excitation flux is produced which is oriented oppositely to the permanent magnet flux, such that the armature (5) occupies the opposite position until the coil current is switched off and thus the excitation flux is obviated, whereafter the armature (5) moves back into the position with the high adherance force, thus possessing a monostable switching behaviour.
3. Control device according to claim 1, in which the armature (5) is linearly displaceably supported in the coil body (4) or guided outside of the coil body (4).
4. Control device according to claim 1, in which the armature (50) is pivotable around a pivot axis (51).
5. Control device according to claim 1 with adjustable abutments (6,7) for the influencing of the magnetic flux by the selectable distance D₁ and D₂ between armature (5) and pole face surfaces P₁P₂₂ and P₂P₁₁ in order to change the switching behaviour of the magnet system.
6. Control device according to claim 1, in which the armature (52) is fixed in the coil body (53) and the coil body (53) with the armature (52) is pivotable around the pivot axis (54).
7. Control device according to claim 1, including armature (50) designed as retaining hook (55).

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