JPH0516126B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic switch that can be used to control an electric motor drive device capable of changing the direction of rotation, and the present invention relates to an electromagnetic switch that can be used to control an electric motor drive device capable of changing the direction of rotation. A fixed contact carrier for fixed contacts of the present invention and a slider with a spring-loaded contact bridge arranged on the fixed contact carrier. This type of electromagnetic switch is for example DE-
AS2143488 is known. In each case, two mutually opposite stationary contacts and their associated contact bridges form a double-blocking working contact. For example, for the control of a three-phase alternating current motor with variable direction of rotation, two such electromagnetic switches are required, each with a slider operatively connected to its respective armature, each with at least two, but not all, designated poles. In case of disconnection, operate three working contacts. Since the change in direction of rotation is effected by phase exchange, the two working contacts of one electromagnetic switch must be wired with the two working contacts of the other electromagnetic switch so that two pairs of contacts act as a transfer switch. Furthermore, the two electromagnetic switches must be closed to each other either by a mechanical connection of their armatures or electrically through auxiliary contacts to prevent a simultaneous reaction of the two electromagnetic switches and thus a short circuit between the two phases. That is, in the past, two electromagnetic switches were required to change the direction of rotation of the electric motor, resulting in a complicated configuration and increased size.

It is an object of the present invention to provide an electromagnetic switch which can be simplified in structure and miniaturized, and in which polarity can be changed.

The present invention comprises: (a) provided so as to be reciprocally movable and having two end positions;
(b) springs 32a, 32b that maintain the slider 10 in the intermediate position with the spring force; (c) the slider 10 with the spring force of the springs 32a, 32b; (d) along one movement direction on one side of the slider 10, a first support 400a and a second support; 600
and a third support 400b are arranged in this order, and (e) along the one movement direction on the other side of the slider 10, a fourth support 300 and a third support 400 are arranged corresponding to the first support 400a. (f) The first support 400a is placed in the fifth support 500 facing the second support 600 at a position far from the second support 600. (g) The second support 600 has a second contact 6b facing the first support 400a side closer to the first support 400a.
and the third support body 40 near the third support body 400b.
(h) The third support 400b has a fourth contact 4b facing the second support 600 at a position far from the second support 600. (i) The fourth support 300 has a fifth contact 3a facing the fifth support 500 at a position far from the fifth support 500, and a fifth contact 3a near the fifth support 500. (j) The fifth support 500 has a seventh contact 5a facing toward the fourth support 300 and opposite to the fourth support 300, and a fourth support 500. (k) protrudes to both sides of the slider 10 and faces the first and fifth contacts 4a, 3a; (l) a second contact bridge 34b that protrudes on both sides of the slider 10 and faces the second and sixth contacts 6b, 3b; (m) a third contact bridge that protrudes on both sides of the slider 10 and faces the second and sixth contacts 6b, 3b; and a third contact bridge 56a facing the seventh contacts 6a and 5a; (n) a fourth contact bridge 56b protruding from both sides of the slider 10 and facing the fourth and eighth contacts 4b and 5b; (o) First and second contact bridges 34a, 34b
a first compression spring interposed therebetween; (p) third and fourth contact bridges 56a, 56b;
(q) a conductor 15 connecting the first and third supports 400a, 400b, and (r) when the slider 10 is in the intermediate position, 4 bridges 34a, 34b, 56a, 5
6b is the first to eighth contacts 4a, 6b, 6a, 4
b, 3a, 3b, 5a, 5b, (s) When the slider 10 is at one end position, the first
The contact bridge 34a connects the first and fifth contacts 4
a, 3a, and the third contact bridge 56
a is in contact with the third and seventh contacts 6a and 5a, and (t) when the slider 10 is at the other end position, the second
The contact bridge 34b connects the second and sixth contacts 6
b, 3b, and the fourth contact bridge 56
b is an electromagnetic switch characterized in that it comes into contact with the fourth and eighth contacts 4b and 5b.

The slider of the electromagnetic switch according to the invention can in principle be operated through any magnetic drive which provides three stable points or connection states. However, it is preferred to use a non-polarized dual magnetic system or a polarized magnetic drive with two excitation coils.

The drawing shows an embodiment of an electromagnetic switch according to the invention with two types of magnetic drive devices. Figure 1 shows a three-phase AC power supply R, S, T, which can change the rotation direction using the electromagnetic switch of the type proposed here.
A circuit for controlling a three-phase AC motor M supplied with power from Mp is shown. The phases R, S, T are coupled to the corresponding connections of the motor through a contact arrangement with contact connections 1 to 6. The contact arrangement is configured as a three-pole changeover switch with three positions: ``on'', ``off'', and ``on''. On the common slider 10 there are for this purpose three contact bridges 12, 34, 56.
each with four fixed contacts for a contact bridge, e.g. 1a, 1b and 2
a, 2b, and works in conjunction with a normal double cut-off changeover switch. The three contact bridges 12, 34, 56 thus form three parallel contact surfaces with the associated stationary contacts. To change the direction of rotation of the motor M, it is necessary to replace two of the three phases at the corresponding connections of the motor. The contact mechanism of an electromagnetic switch constructed along this circuit would, however, require 12 fixed contacts (including the dormant all-pole disconnect shown here), resulting in a total of 6 conductors according to the circuit shown. They would have to be connected to each other by bridges.

A slider 10 with contact bridges 12, 34, 56 is connected to an armature of a magnetic drive,
It is configured in this case as a polarized magnetic drive with two coils MC1 and MC2. The end of the winding of one coil MC1 and the beginning of the winding of the other coil MC2 are combined at point A3,
It is connected via a working contact key T4 to one connection of a controlled DC voltage source. The winding start A1 of the coil MC1 is connected to both connections of this DC voltage source through a switching contact T5, and the winding end A2 is likewise connected through a switching contact T6. As will be further explained later using examples, this magnetic drive device is constructed in cooperation with the slider 10, and has three stable locations, so that the right and left end positions and all contacts are open. Each requires only a single short current pulse to reach the intermediate position. Starting from the central rest position shown, actuation of key T5, which causes counterclockwise rotation of motor M, for example, causes the control current to flow in coil MC1.
When the key T6, which causes the motor M to rotate clockwise, is operated, the flow goes in the other direction. However, when key T4 is actuated, the control current flows through both coils MC1 and MC2 in the opposite direction, thus bringing slider 10 to an intermediate position corresponding to the stoppage of motor M.

The electromagnetic switch proposed here has a single contact mechanism, and instead of 12 fixed contacts, only 7 fixed contacts are required according to the contact connections 1 to 6 of Fig. 1 to realize the circuit according to Fig. 1. 1, and instead of six conductor bridges, only a conductor bridge, designated 15 in FIG. 1, is required to connect the two connections 4.
This contact pair is illustrated in Figures 2a, 2b and 3, with Figure 2a being a sectional view taken along line A--A in Figure 3;
FIG. 2b shows a cross-section in the same cutting direction as FIG. 2a, but with coil connections placed on both sides of the connecting contacts, and FIG. 3 shows a cross-section along line D-D in FIG. 2a. shows. Figures 2a and 2b have the same reference numbers. However, for ease of viewing, not all reference numbers are necessarily listed on both drawings. As is clear from Figures 2a and 2b,
The common slider 10 has three contact bridges 12,3
two individual bridges 12a, 12b or 34, each springing together;
a, 34b or 56a, 56b. Each of these contact bridges defines a contact area, of which, for example, the first one is located along the line D--D. In the first contact area corresponding to the connections 1 and 2, the respective fixed contacts in FIG.
a, 1b or 2a, 2b are each constructed as a one-piece stationary contact molding 100 or 200, which is approximately U-shaped and has connecting screws 101 or 201 on its lateral legs. One in each case of the legs of the fixed contact molding, here contact point 1a
Or that for 2a is angled and bent at right angles simply for reasons of maintaining the necessary linear and creepage distances.

In the second contact region, which includes the contact bridges 34a, 34b, a fixed contact molding 300 of the same type for the connection 3 is provided with contact points 3a and 3b. The lateral legs are provided with connecting screws 301. On the other hand, the fixed contact molded body 40 belonging to the contact connection part 4 opposite to this
0a is formed into an angular shape as shown in the sketch of FIG. 7, and has only one contact point 4a on one of its legs. The contact points 3a and 4a are connected to each other at the left end position of the slider 10 by a single bridge 34a. Angled fixed contact molded body 4
The other leg of 00a is provided with a connecting screw 401a.

A so-called space follows the second contact area. It includes a contact connection 6 but not a contact bridge.
On the contact surface containing the subsequent third contact bridges 56a, 56b, a fixed contact molding 500 with a connecting screw 501 is provided in the connecting part 5, corresponding to the fixed contact molding of the connecting part 1, and thus U They are arranged with contact points 5a, 5b facing each other in the form of a letter. There is a second contact connecting part 4 oppositely, and the contact molded body 400b is the contact molded body 40 on the second surface.
Although it has an angular shape like 0a, it is mirror symmetrical to this, and has a contact point 4b and a connecting screw 401b. The contact connections 4 of the second and third contact areas are connected to conductor bridges 15
are connected to each other by This double contact connection part 4
In the space between there is a contact connection 6 with a connection screw 601. This contact connection 6 consists of a U-shaped stationary contact profile 600, which corresponds to the diagram in FIG. . Therefore, in the rightmost position of the slider 10, the single bridge 34b of the second plane connects the contact point 3b with the contact point 6b, whereas in the leftmost position of the slider 10, the single bridge 56a of the third contact surface connects the contact point 3b with the contact point 6b. 5a is connected to the contact point 6a.

A location in the case 20 of the contact mechanism opposite the connecting portion 6 is used to house the coil connecting portion A3 in FIG. The end of coil MC1 and the beginning of coil MC2 are grouped together in connection part A3.
In the example of FIG. 2a, the coil connections A1 and A2 are grouped together in a so-called coil connection surface to the left of the switching contact. In Figure 2b, one coil connection surface is added on each side of the switching contact, although it requires a little extra space;
The coil MC1 has connection parts A1 and A2, and the other coil connection surface has connection parts A3 and A4 of the coil MC2. This somewhat extra space-consuming structure, however, has the advantage that both coils MC1 and MC2, together with their connections, are of the same type and can therefore be manufactured more cost-effectively in some cases.

The configuration and mounting of the coil connections within the case 20 of the contact mechanism is not critical to the invention. The initial contact area may also be dispensed with if all-pole switching is abandoned or if electromagnetic switches are used to change the direction of rotation of a DC machine by changing poles. slider 1
0 can in principle be operated by any magnetic drive which guarantees the tristable position of the slider 10 described above. Two embodiments are shown in FIGS. 4 to 6. Figures 4a and 5 are respectively 2a
FIG. 3 is a cross-sectional view along line B-B in the figure.

The electromagnetic switch shown in FIGS. 4a and 4b includes a polarized magnetic drive which can be controlled in the manner described in connection with FIG. The magnetic drive device includes a coil former 40, which is divided into two chambers, one of which contains the coil MC1.
, and the other one includes a coil MC2. Winding form 40
An armature 41 is movably arranged in the borehole and protrudes from the end face of the former 40 on both sides and is provided with an electrode plate 42 or 43 in each case. On two opposite sides, the former 40 is surrounded by two inner yokes 44a and 44b and, spaced apart therefrom, by outer yokes 45a and 45b.

The pole plates 42 and 43 of the armature 41 are connected to the yoke 44
It works together with the end faces of a, 44b and 45a, 45b facing towards it. The armature 41 is connected at its left end to one end of a lever 29 which extends beyond the corresponding plate 42 and can be pivoted around the point of rotation 28, and at its other end to a three contact bridge. 12a, 12b and 34a, 34b and 5
It is operatively connected to a slider 10 comprising 6a, 56b. A stable central position of the slider 10 is ensured by a center position spring, which consists of prestressed helical compression springs 32a, 32b located in a cutout in the case 20.
The mutually opposite ends of the coil springs 32a, 32b in their central rest position, which is shown more clearly in FIG. I feel supported. Both coils MC1 or MC2
If the slider 10 is moved from its rest position by excitation of one of the coil springs, therefore only the coil spring in the direction of movement of the slider is compressed, while the other coil spring is compressed only in the case projection while retaining its initial stress. Supported.

FIG. 5 shows a non-polarized magnetic drive. This is the two winding forms 5 for coils MC1 and MC2.
1 and 52, surrounded on two opposite sides by a soft magnetic yoke 53, the central leg 53a of which is located between the formers 51 and 52. At its end faces, the yoke 53 passes into cores 54 and 55 which enter into the boreholes of the formers 51 and 52. A guide rod 57 for a soft magnetic armature 58 is movably arranged in this core. A lever 29 is linked to this guide rod, which can be pivoted around a pivot point 28 for actuating the slider 10. In other respects this switch corresponds to that according to FIGS. 4a and 4b. The illustrated center position of the armature 58 is again ensured by two-component center position springs 32a, 32b of the type seen in FIG.

The above-mentioned fixed contact molded bodies 100, 200, 30
0,400a, 400b, 500, 600 serve as supports for supporting fixed contacts.

To further describe the configuration, the slider 10 is provided so as to be able to freely reciprocate, and can have two end positions and an intermediate position between the end positions. Springs 32a and 32b maintain the slider 10 in an intermediate position with spring force. Coils MC1 and MC2 are
The slider 10 is brought to each of its two end positions by electromagnetic force against the spring force of springs 32a, 32b. A support 400a, a support 600, and a support 40 are arranged along one movement direction (direction from left to right in FIG. 2A) on one side of the slider 10 (downward in FIG. 2A).
0b are arranged in this order. slider 10
On the other side (upper part of FIG. 2a), along the one movement direction, a support 300 is placed corresponding to the support 400a.
and a support body 500 are arranged corresponding to the support body 400b. The aforementioned references 1a, 2a, 3a, 4
A contact point indicated by a, etc. is sometimes referred to as a contact point.

The support 400a has a contact point 4a facing the support 600 at a position far away from the support 600 (on the left in FIG. 2b). The support body 600 has a contact point 6b that is close to the support body 400a and faces the support body 400a side (the left side in FIG. 2a), and a contact point 6a that is close to the support body 400b and faces the support body 400b side (the right side in FIG. 2a). has. The support body 400b is the support body 6
At a position far away from 00 (to the right in Figure 2b),
Contact point 4 facing the support body 600 side (left side in Fig. 2a)
It has b.

The support 300 has a contact point 3a facing the support 500 side (right in FIG. 2a) at a position far away from the support 500 (left in FIG. 2b), and a contact point 3a facing the support 500 (right in FIG. 2a).
It has a contact point 3b which is opposite to the contact point 3a.
The support body 500 has a contact point 5a that is close to the support body 300 (left side in FIG. 2a) and facing the opposite side from the support body 300 (right side in FIG. 2a), and a contact point 5a that is far away from the support body 300 ( (on the right in FIG. 2b), the support 300
It has a contact point 5b facing the side (left side in FIG. 2a). First to fourth contact bridges 34a, 34b, 5
6a and 56b are on both sides of the slider 10 (second a
It protrudes to both sides in the vertical direction (in the figure and in FIG. 2b). Contact bridge 34a faces contacts 4a, 3a. The contact bridge 34b has contacts 6b, 3b
to face. The contact bridge 56a has contacts 6a,
5a. The contact bridge 56b is connected to the contact 4
b, facing 5b.

A compression spring is interposed between contact bridges 34a, 34b. Another compression spring is interposed between the contact bridges 56a, 56b.

When the slider 10 is at an intermediate position in the reciprocating direction as shown in FIGS. 2a and 2b, the contact bridges 34a, 34b, 56a, 56b are connected to the contacts 4a, 6b, 6a, 4b, 3a, 3b, 5a,
It is separated from 5b. When the slider 10 is in one end position (to the left in FIGS. 2a and 2b), the contact bridge 34a abuts the contacts 4a, 3a, and the contact bridge 56a abuts the contacts 6a, 5.
a. Slider 10 is at the other end position (second
2b), the contact bridge 34b abuts the contacts 6b, 3b, and the contact bridge 56b abuts the contacts 4b, 5b.

The present invention can be used not only for changing the direction of rotation of an electric motor, but can also be widely implemented for reversing the polarity of a power supply to a load of such a motor.

As described above, according to the present invention, an electromagnetic switch is realized which has a relatively simple structure, is miniaturized, and can change the polarity of a power source and apply it to a load or the like.

[Brief explanation of the drawing]

1 is a complete wiring diagram for controlling a three-phase alternating current motor with reversible direction of rotation using an electromagnetic switch according to the invention; FIG. 2a is a cross-sectional view of the contact mechanism of the electromagnetic switch along line A-A in FIG. 3; , Figure 2b is Figure 2a
Figure 3 is a sectional view of the contact mechanism of the electromagnetic switch along the line D--D in Figure 2a; Figure 2a is a cross-sectional view of the electromagnetic switch along line B-B in Figure 2a, Figure 4b is a cross-sectional view of the electromagnetic switch along line E-E in Figure 4a, and Figure 5 clearly shows another magnetic drive device. 2a is a cross-sectional view of the electromagnetic switch taken along line B-B in FIG. 2a, FIG. 6 is a partial cross-sectional view taken along line C-C in FIGS. 4 and 5, and FIG. Figure 8 shows a fixed contact configured in a U-shape. MC1, MC2...Coil, 4,6...Contact connection part, 5...Connection part, T4...Work contact key, T
5, T6...Switching contact key, 10...Slider,
12, 34, 56...Contact bridge, 15...Conductor bridge, 20...Case, 28...Rotation point,
29... Lever, 41, 58... Armature, 42,
43... Pole plate, M... Three-phase AC motor, R, S,
T, Mp...Three-phase AC power supply.

Claims (1)

[Claims] 1. (a) A slider 10 that is provided to be able to freely reciprocate and has two end positions and an intermediate position between the end positions; (b) A spring force is applied to the slider 10 to move the slider 10 to the intermediate position. (c) coils MC1, MC2 which bring the slider 10 to two respective end positions by electromagnetic force against the spring force of the springs 32a, 32b; (d) the slider 10 A first support body 400a and a second support body 600 are arranged along one movement direction on one side.
and a third support 400b are arranged in this order, and (e) along the one movement direction on the other side of the slider 10, a fourth support 300 and a third support 400 are arranged corresponding to the first support 400a. (f) The first support 400a is placed in the fifth support 500 facing the second support 600 at a position far from the second support 600. (g) The second support 600 has a second contact 6b facing the first support 400a side closer to the first support 400a.
and the third support body 40 near the third support body 400b.
(h) The third support 400b has a fourth contact 4b facing the second support 600 at a position far from the second support 600. (i) The fourth support 300 has a fifth contact 3a facing the fifth support 500 at a position far from the fifth support 500, and a fifth contact 3a near the fifth support 500. (j) The fifth support 500 has a seventh contact 5a facing toward the fourth support 300 and opposite to the fourth support 300, and a fourth support 500. (k) protrudes to both sides of the slider 10 and faces the first and fifth contacts 4a, 3a; (l) a second contact bridge 34b that protrudes on both sides of the slider 10 and faces the second and sixth contacts 6b, 3b; (m) a third contact bridge that protrudes on both sides of the slider 10 and faces the second and sixth contacts 6b, 3b; and a third contact bridge 56a facing the seventh contacts 6a and 5a; (n) a fourth contact bridge 56b protruding from both sides of the slider 10 and facing the fourth and eighth contacts 4b and 5b; (o) First and second contact bridges 34a, 34b
a first compression spring interposed therebetween; (p) third and fourth contact bridges 56a, 56b;
(q) a conductor 15 connecting the first and third supports 400a, 400b, and (r) when the slider 10 is in the intermediate position, 4 bridges 34a, 34b, 56a, 5
6b is the first to eighth contacts 4a, 6b, 6a, 4
b, 3a, 3b, 5a, 5b, (s) When the slider 10 is at one end position, the first
The contact bridge 34a connects the first and fifth contacts 4
a, 3a, and the third contact bridge 56
a is in contact with the third and seventh contacts 6a and 5a, and (t) when the slider 10 is at the other end position, the second
The contact bridge 34b connects the second and sixth contacts 6
b, 3b, and the fourth contact bridge 56
b is an electromagnetic switch characterized in that it comes into contact with the fourth and eighth contacts 4b and 5b.