JPS6132771B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a protective tube configured as a coil frame with an armature disposed therein, and a protective tube fixed and fixed within the coil frame.
The present invention relates to an electromagnetic switch having buried contact terminals, coil terminals, and magnetic pole pieces.

This type of electromagnetic switch is described in German Patent Publication No.
It is known from No. 1909940. Although it is small, it is highly efficient, and because the contact and winding are separated, the contact is highly reliable. Furthermore, this switch with switching contacts can be manufactured at low cost. Despite these favorable features, this relay is not suitable for use with a make contact separated from a back contact or for double opening or closing of a circuit.

Electromagnetic switches with contacts satisfying the above characteristics are known, for example, from DE 1614943 and US Pat. No. 3,768,051. The technology uses two bearingless contacts with sealed contact capsules.
A configuration is disclosed that is disposed between a pair of fixed contacts. Permanent magnets are supported in the case on both sides of the contact capsule, so different magnetic poles face each other,
A magnetic path is formed via the armature. An excitation winding is mounted on the contact capsule between the magnets, which in some cases are configured in the form of a bridge and in some cases are provided with pole pieces. The known switch has bistable operation and is driven by an impulse current. However, constructions that require, for example, a case to house the contact capsule and the magnet have drawbacks, such as being expensive and the contact capsule creating a functionally unnecessary magnetic gap, which results in relatively low efficiency. The use of bridge-shaped permanent magnets is expensive to manufacture, and when such permanent magnets are used, the winding chamber in which the excitation winding is installed is limited by the permanent magnets, making it difficult to increase the number of turns. I couldn't do it. Therefore, it is almost impossible to increase the response sensitivity by increasing the number of turns.

The invention thus provides an electromagnetic switch of the type mentioned above which has a simple and compact construction, is easy to manufacture, has a high efficiency and, in addition, provides a switching action, for example monostable or in which the armature can also assume intermediate positions. It is about providing the equipment.

According to the present invention, the armature has two free ends provided with contacts, and a contact chamber is formed on both sides of the protective tube in the coil frame, and in the contact chamber, the free ends of the armature are respectively connected to the free ends. The magnetic pole piece is arranged symmetrically with respect to the coil axis and an axis perpendicular to the coil axis, facing a magnetic pole piece end portion having a contact protruding from the wall of the contact chamber corresponding to It is arranged.

By using the coil housing as a protective tube and as a support for the permanent magnets, pole pieces and contacts, all magnetic circuit components are arranged within a very small area, which limits losses to a minimum. An electromagnetic switch with high efficiency can be obtained. According to the configuration of the present invention, when designing the sizes of the coil and the magnet with respect to the available space, each can be designed completely independently, and the magnetic pole piece is designed to prevent leakage magnetic flux from the coil frame flange near the end face of the coil winding. It is inevitably located in an area with few.

According to a preferred embodiment of the invention, one permanent magnet is formed on each coil frame flange between each pole piece and the ferromagnetic case. It is placed in a recess that matches the shape of the permanent magnet.

Since the permanent magnet is formed into a substantially rectangular parallelepiped shape, it can be easily manufactured. The chamber provided to accommodate the permanent magnet of the plastic coil frame is configured to be electrically insulated from the conductive pole piece or case cap.

According to another embodiment of the invention, the armature disposed within the protective tube is unsupported (not directly supported but movable within the protective tube). In this case, the polarity of the permanent magnet is determined such that the magnetic pole pieces on one side of the coil axis have different polarities and the armature contacts the magnetic pole pieces. When the coil is energized, the armature is magnetized, so that it is repelled from this magnetic pole piece and attracted to the opposing magnetic pole piece. In this case the armature operates approximately parallel to the coil axis. In order to reliably avoid that the armature, which is constructed as a long thin plate with a rectangular cross section, tilts when subjected to strong vibrations when de-energized and bridges the opposing pole piece, i.e., a bad electrical connection. An armature disposed within the protective tube can be supported by a spring. The spring ensures that the armature is always parallel to the pole piece. In this case, the spring force of the spring may be weak so that the bistable opening/closing operation continues.

The spring support structure is as follows. That is, in the center of one or both sides of the armature, a leaf spring is fixed, which extends in the longitudinal direction of the protection tube, is given a preload, and comes into contact with the wall surface of the protection tube. In this way, not only the armature is secured, but also the opening/closing operation can be easily adjusted. When using a suitably strong single spring, the spring force is greater than the magnetic force of the permanent magnet and a monostable opening/closing action is obtained.

In the present invention, when a long and thin plate made of soft iron is used as an armature, for example, the armature can be constructed so that its ends are larger than its center. This configuration provides particularly high contact pressures.
If necessary, the enlarged end can also be split in order to form a double contact.

According to the present invention, the side surfaces of the opposing magnetic pole pieces protrude from the wall surface of the contact chamber, are bent in the coil axis direction between the contact chamber and the protective tube, and the winding is parallel to the armature. Extending to correspond to both ends of the chamber,
Further, a contact material is attached to each contactable area between the free end of the armature and the bent end of the pole piece.

The magnetic pole face consists of the bent end of the magnetic pole piece,
Since the attraction force and the contact pressure are increased, the contacts can be provided with a plating, and it is also possible to use a diaphragm that functions as an integral contact and a magnetic gap. Therefore, a high current load capacity of the contact can be obtained, and in addition, the contact resistance is also lower than that of a plated contact. In this case, greater tolerance to wear can be achieved and the life of the contacts can be extended.

Further, the conductive magnetic pole plate is adhered to the corresponding contact terminal before the embedding process. This configuration makes it possible, for example, to unify the plate pieces holding the contact terminals and the coil terminals. For example, in this case the plate material for contact terminals and coil terminals can be soldered without further processing and corrosion-resistant German silver can be used.

In order to maintain high contact pressure, the bent end of the magnetic pole piece is led out parallel to the armature with a relatively large magnetic pole surface to the end of the winding chamber where there is little leakage magnetic flux. There is. In this case, despite having a large magnetic pole surface, the magnetic pole piece is firmly embedded in the coil frame and is accurately fixed, so that no adjustment is necessary. For this purpose, according to a preferred embodiment of the invention, the ends of the pole pieces facing the permanent magnet are embedded in the partition wall of the magnet chamber, each pole piece having exposed parts on both sides, the exposed parts being separated by a distance a. The exposed portions of the pole pieces are arranged adjacent to the end face of the coil frame within the magnet chamber.

The contact spacing is determined by inserting a tool of a predetermined width in the process of injection molding, transfer molding, or compression molding the coil frame. For this purpose, the bent end of the pole piece is pressed against the above-mentioned insert by a lateral insert acting on the exposed portion on the opposite side, so that the desired contact spacing can be formed precisely. .

A further embodiment of the invention provides that the coil housing consists of two halves made of plastic that can be firmly welded together, the welding being such that the material deformation during welding of the two halves of the coil housing is effected by laser or ultrasonic waves. At least one of the two coil frame halves is provided with a flat edge-shaped protrusion extending along the plane to be joined, or the first coil frame half is provided with a flat edge-like projection extending along the joining plane. The second half has an extending flat-edge protrusion, the second half has a groove corresponding to the flat-edge protrusion, and the assembly gauge that determines the contact spacing or armature travel width is used to detect the contact material of the pole piece during the welding process. The coil body is inserted into both halves of the coil body between the attached and opposing ends.

In this case, deformation of parallel protrusions occurs along the contact surface, but by using an assembly gauge, the desired armature travel width or contact gap can be easily adjusted.
and accurately held. Compared to switches bonded by known methods, assembly gauges allow the various armature travel widths or contact gaps to be determined and to obtain various voltage stability.

In order to increase efficiency, the switch is surrounded by a ferromagnetic case that conducts the magnetic flux of the permanent magnet, or a yoke is provided between the pole piece of the permanent magnet and the opposite side of the coil flange.

Further, in order to seal the contact chamber, a rectangular parallelepiped permanent magnet is provided between the contact chamber and the magnet chamber so as to be able to be adhered, so that the contact chamber can be easily sealed.

Furthermore, a permanent magnet housed in a magnet chamber adjacent to the contact chamber is made of barium ferrite or a so-called rare earth and is activated to function as a getter. As a result, even if gas is generated at the contact during operation and impairs the characteristics of the contact, the gas can be reliably adsorbed. In addition, it is also advantageous to coat the relatively large-walled chamber provided for the armature with a getter material that adsorbs special gases. For example, in splitting the coil into two, it is conceivable to use the wall surface of the chamber provided for the armature. Activation of the permanent magnet, which acts as a getter, is carried out in a vacuum of 10 ^-5 Torr, with the simultaneous application of heat if necessary, and the coil frame can be degassed at the same time as this process. In this case, it is particularly effective if the getter, which adsorbs harmful gases, is located close to the contact.

Preferably, a film coated with adhesive is fixed to the permanent magnet on its contact surface to the contact chamber. In this case, the adhesive film is provided in such a way that it primarily extends only in the edge region of the permanent magnet.

By using such an adhesive film, it is possible to avoid applying adhesive by the mesh printing method, which is complicated in terms of manufacturing technology and has the risk that adhesive droplets containing a solvent may be applied to areas other than the adhesive surface. Ru.

According to a further development of the invention, a chamber is provided between the contact chamber and the magnet chamber, which is suitable for accommodating the molecular sheave or the auxiliary getter, and the molecular sheave or the auxiliary getter or the permanent magnet is placed in a plastic coil frame. Fixation is performed by thermally deforming the end of the . In this case, the permanent magnet or auxiliary getter is securely fixed in a single step and there is no need to use adhesives.

Another aspect of the present invention is to form a recess around the contact terminal or coil terminal on the lower side of the coil frame, and to fill at least a portion of this recess with a poured resin. This arrangement makes it possible to provide a particularly heat-resistant fixing part for the contact terminals and the coil terminals, so that even if an excessive temperature rise occurs in the terminal group, for example during soldering, the position of the terminals is well maintained. Furthermore, a case can be provided to seal the electromagnetic switch, and a sealant is filled in the gap between the case and the coil frame. In this case, the case can be made of a ferromagnetic material and can have magnetic shielding and conduction functions at the same time. Finally, when using an electromagnetic switch with a printed circuit, it is preferable to arrange the contact terminals and coil terminals led out from the electromagnetic switch so as to match a so-called 5 mm raster.

Next, the present invention will be described in detail based on embodiments shown in the figures. FIGS. 1 and 2 show an electromagnetic switch of the present invention in which permanent magnets disposed on the flanges of the coil frame are respectively placed between the terminals of two opposing magnetic pole pieces,
Figures 3 and 4 show an electromagnetic switch in which the armature is supported by a spring.

The switch shown in FIGS. 1 to 4 has a coil frame 1 configured as a protection tube 2, and has a coil frame 1 that is unsupported (not directly supported but movable within the protection tube 2). A ferromagnetic armature 3 is provided. The coil frame 1 has contact terminals, coil terminals 4, 4', 5, 5', and magnetic pole pieces 6,
6', 7, 7' are fixed and planted. Armature 3
The ends 9, 9' are each provided with a contact 20, which faces the pole pieces 6, 6', 7, 7' provided with the contacts 20 in the contact chambers 8, 8'. In this case, the contact chambers 8, 8' can be provided as chambers adjacent to the protection tube, or alternatively they can be provided as part of the protection tube 2. Each pole piece 6, 6',
7, 7' and the ferromagnetic resistant case, permanent magnets 13, 13' are installed in concave chambers formed in the flanges 33, 33' of the coil frame symmetrically with respect to an axis perpendicular to the coil axis. It is arranged. The permanent magnet is separated from the case, for example by a gap or an insulator, so that no electrical shunts occur. If ceramic magnets are used, the above configuration is not necessary. The unsupported armatures 3, 3' move approximately parallel to the coil axis when the electromagnetic switch is energized. Therefore, the polarities of the permanent magnets 13, 13' disposed on the coil frame flanges 33, 33' are arranged in different directions with respect to an axis perpendicular to the coil axis.

Since this switch has a simple structure, it is easy to manufacture. For example, the coil frame 1 is made up of two identical halves 1', 1'', and the halves are glued together before the coil winding 43 is wound and the permanent magnets 13, 13' are arranged, or Alternatively, they may be bonded together by laser welding.The protection tube 2 and the contact chambers 8, 8' are thus hermetically sealed.The magnetically active components are thus arranged in a very small chamber, and the magnetic pole pieces 6, 6 ', 7, 7' reach the area near the end of the coil winding 43 where there is little leakage magnetic flux, so overall loss is small and high efficiency can be obtained. ′
The size of each can be freely selected, and therefore, it is particularly suitable for obtaining high response sensitivity and large contact pressure.

In order to obtain a large contact pressure, the width of the end of the armature 3 can also be increased, as shown in this embodiment. The armature 3 is provided in a substantially plate-like shape, and has a rectangular cross section.

Furthermore, in the electromagnetic switch equipped with the unsupported armature 3 shown in FIGS. 1 and 2, two opposing magnetic pole pieces 6, One permanent magnet 13, 13' is disposed between the ends 10, 11, 10', 11' of the magnets 6', 7, 7', respectively. Permanent magnet 1
3, 13', the chambers consisting of the protective tube 2, the contact chambers 8, 8', and the magnet chambers 12, 12' are formed in line with the coil frame 1.
The whole empty copper can be easily cleaned, for example, by using an ultrasonic bath. The magnetic pole pieces 6, 7 protruding from the side chambers of the contact chambers in the coil frame flanges 33, 33' are bent toward the center of the switch, and contacts are formed at ends 18, 19 mutually parallel to the coil axis. 20 is firmly press-fitted or crimped. After cleaning, the contact chambers 8, 8' having contact surfaces are connected to the coil frame flanges 33,
Permanent magnets 13, 13' in 33' further preferably cover films 28, 2 with adhesive on both sides.
8'. The above film is mainly attached to one edge 29, 2 of the permanent magnet 13, 13'.
Extends only 9'. Coil frame flange 33, 3
The pole pieces 6, 6', 7, 7' embedded in 3' have exposed portions 21, 22, 23, 24 on both sides. The exposed portions on each side are offset from each other by a distance a.
In order to precisely form the gap between the ends 18, 19 of the bent pole pieces 6, 7 with the contacts 20 during the embedding process, for example injection molding, compression molding or transfer molding, the above-mentioned distance a will occur. A side slide of a manufacturing tool is applied to the exposed portions 21, 23 of the magnetic pole pieces 6, 7 during the embedding process, and the magnetic pole pieces 6,
A punch introduced into the ends 18, 19 from the preparation portions 22, 24 of 7 is pressed, and the two folds of the pole pieces 6, 7 which determine the outer shape of the contact chamber 8 and the magnet 13 or the contact spacing are pressed by the punch. bent end 18,1
9 intervals are formed with high precision.

The coil frame 1 is equipped with an excitation coil 43, and after connecting the excitation coil 43 and the coil terminals 5, 5', and 5'', the electromagnetic switch is connected to approximately 10 ^-5 to eliminate moisture.
It is placed in a vacuum of 100°C and subjected to a temperature of 100°C to 150°C. At this time, permanent magnets 13, 13' made of barium ferrite or rare earth
can be activated as a getter. In addition, the vacuum of approximately 10 ^-5 Torr is replaced by a protective gas at standard pressure (approximately 760 Torr) and the protective tube 2 and contact chambers 8, 8' are closed with permanent magnets as described above.

To improve magnetic shielding and magnet efficiency, the electromagnetic switch is surrounded by a case 57 of ferromagnetic material,
The case is held in place with a sealant, such as a pouring resin known under the trade name "Araljit." This significantly improves the sealing properties and the mechanical and functional stability of the switch at the same time. When the coil frame 1 is made of thermoplastic plastic, it is desirable to provide a recess around the contact terminals and the coil terminals 5, 5', 5'' and to fill at least a portion of this recess with a sealant. This is because sealants have better shape stability than thermoplastics, and therefore the positions of contact terminals and coil terminals are reliably maintained even when excessively heated during soldering.

The getter action of the activated permanent magnets 13, 13' may not always be sufficient in some cases, and some distance is required in any case between the permanent magnets 13, 13' and the pole pieces. An auxiliary chamber 30 is provided in which a special getter or molecular sieve is stored. Instead of a getter, a getter material can also be encapsulated in the cavity of the coil frame, which serves as a protective tube, for example, by vapor-depositing an electron tube. This arrangement prevents outgassing from the plastic and ensures good contact between the contacts.

3 and 4 have an integrated coil frame like the switches in FIGS. 1 and 2, but the armature
shows an electromagnetic switch supported by a spring in the protective tube 2. In detail, in this embodiment, the armature is provided on one side (see Fig. 3) or on both sides (see Fig. 4) of the armature, extends substantially in the longitudinal direction of the protection tube, and is applied to the wall surface of the protection tube with a preload. a leaf spring 66 abutted against,
66' is fixed. In addition to preventing the armature 3 from tilting when a strong impact is received, the spring can also adjust the opening/closing operation. In the embodiment shown in FIG. 3, if the spring force is greater than the magnetic force of the permanent magnet, a monostable opening and closing operation is obtained. In the embodiment according to FIG. 4, the springs 66, 66' can be weakened so that the bistable opening and closing operation continues.

[Brief explanation of the drawing]

Figure 1 shows an embodiment of the electromagnetic switch of the present invention.
FIG. 2 is a sectional view taken along line 1--' in FIG. 1, and FIGS. 3 and 4 show other embodiments of the present invention. 1... Coil frame, 1', 1"... Half body, 2... Protection tube, 3... Armature, 5, 5', 5"... Coil terminal, 6, 6', 7, 7'... ...Pole piece, 8, 8'...
Contact chamber, 10, 10', 11, 11'... end, 1
2, 12'... Magnet chamber, 13, 13'... Permanent magnet, 18, 19... End, 20... Contact, 21,
22, 23, 24...Exposed portion, 28, 28'...
... Film, 29, 29' ... Edge, 30 ... Auxiliary chamber, 33, 33' ... Flange, 43 ... Excitation coil, 57 ... Case, 58 ... Sealant, 6
6,66'...plate spring.

Claims (1)

[Claims] 1. Fixing the contact terminal, coil terminal, and magnetic pole piece.
In an electromagnetic switch in which an armature is disposed within a protective tube of a buried coil frame, a protective tube is formed inside the coil frame, and the armature that is not supported by the inner wall of the protective tube, the coil frame, etc. is housed. At the same time, the armature has a free end with contacts attached at substantially both ends thereof, and a contact chamber is formed on both sides of the protective tube of the coil frame, and the free end of the armature is located in the contact chamber at each of the free ends. A magnetic pole piece is disposed symmetrically with respect to the coil axis and an axis perpendicular to the coil axis, facing a magnetic pole piece end portion provided with a contact correspondingly protruding from the wall of the contact chamber, and on a flange of the coil frame. and a permanent magnet is provided between each pair of magnetic pole pieces disposed symmetrically with respect to the coil axis, and a permanent magnet disposed at one end of the armature. The magnetic direction of the permanent magnet is set to be different from the magnetic direction of the permanent magnet disposed at the other end.
An electromagnetic switch characterized in that the armature described above is movable substantially parallel to the coil axis. 2. The electromagnetic device according to claim 1, wherein a leaf spring is fixed to one side of the armature, which extends substantially in the longitudinal direction of the protection tube, is given a preload, and is in contact with the wall surface of the protection tube. switch. 3. The electromagnetic device according to claim 1, wherein leaf springs are fixed on both sides of the armature, extending substantially in the longitudinal direction of the protection tube, being preloaded, and in contact with the wall surface of the protection tube. switch.