JPH04220921A - Electromagnetic contactor - Google Patents

Abstract

PURPOSE:To provide an electromagnetic contactor for connection of a two-side power printed circuit board with which reliance upon the connection with a main circuit wiring plate can be maintained, even when there is a level difference of terminals due to irregularity in processing the components or a level difference due to wiring conductor of the printed circuit board, by adopting the constitution according to the invention as described hereunder. CONSTITUTION:Terminal screw fit parts of a stationary terminal board and a coil terminal board are arranged horizontally at the oversurface of a case, and leaf springs 120, 121 are installed on the oversurfaces of these two terminal boards. Otherwise, at least either of the stationary terminal board and coil terminal board is embodied in floating structures 71, 72 so that the terminal level is adjustable vertically relative to the terminal level of the other. Accordingly the level difference, etc., of terminals due to irregularity in component processing will be absorbed by the leaf springs or the floating structures.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic contactor that can be connected to a printed circuit board, thereby simplifying wiring.

0002

2. Description of the Related Art FIG. 10 is a sectional view showing the structure of a conventional electromagnetic contactor. In the figure, 1 is the mounting base, 2 is the case,
3 is an excitation coil. Reference numeral 4 denotes a fixed iron core, which is disposed at a position facing the movable iron core 5 with a predetermined gap therebetween. 6
is a crossbar made of an insulating material connected to the movable iron core 5, and slidably holds the movable contactor 8 in the window 6a at the top thereof. Further, in FIG. 10, the cross bar 6 is slidably guided by the case 2 so that it can move up and down (not shown).

A contact spring 7 is provided to apply contact pressure to the movable contact 8, and is composed of a compression coil spring. 8a and 8b are movable contacts attached to both ends of the movable contactor 8, and are arranged opposite to the fixed contacts 9a and 10a with a predetermined contact gap.

[0004] Reference numerals 9 and 10 are fixed contacts, each having fixed contacts 9a and 10a connected to one end and terminal screws 11 and 12 screwed to the other end. Reference numeral 13 denotes an arc cover, in which metal arc runners 14 and 15 are fixed, and extinguishes the arc generated between the contacts.

Coil terminals 16 and 17 are arranged at both ends of the excitation coil 3, to which the lead wires at the beginning and end of the winding of the excitation coil 3 are connected. Terminal screws 18 and 19 are screwed into the terminals. Further, 20 is a tripping spring, which connects the crossbar 6 and the movable iron core 5.
is arranged so as to urge the combined body upward in FIG.

Next, the operation will be explained. Excitation coil 3
When a voltage is applied to the fixed iron core 4, the generated magnetic flux causes the fixed iron core 4 to
An attractive force is generated between the movable iron core 5 and the movable iron core 5. Due to this attractive force, the combined body of the movable iron core 5 and the cross bar 6 is pulled out by the tripping spring 20.
It moves downward in FIG. 10 against the urging force of. This movement brings the movable contacts 8a, 8b into contact with the fixed contacts 9a, 10a. Here, since the core gap in the open state shown in FIG. 10 is configured to be larger than the contact gap, the cross bar 6 moves further downward from the contact contact position to obtain a contact wipe, and the contact spring 7 The compressed force is applied to the movable contact 8 and becomes contact pressure. In this way, the contact closing operation is completed.

Next, when the voltage of the excitation coil 3 is removed,
The attractive force between the movable core 5 and the fixed core 4 disappears, and the biasing force of the tripping spring 20 causes the movable core 5 and the crossbar 6 to
The bonded body with is moved upward and the contacts are opened. At this time, the arc generated between the contacts is caused by the arc runner 14.
, 15, the arc is extinguished by being cooled, and the opening operation of the contacts is completed.

FIG. 11 is a circuit diagram showing an example in which the above-mentioned electromagnetic contactor is applied to a semiconductor circuit device, such as an inverter, which is wired using a printed circuit board. In the figure, 51 is a diode module (converter part) that converts 3-phase AC at a commercial frequency into DC, and 52 is a 3-phase AC at a desired frequency.
53 is a smoothing capacitor, 54 is a power supply side terminal, 55 is a load side terminal, and 56 is a control device that controls the operation of the transistor module 52.

Further, reference numeral 57 denotes a rush current limiting resistor, which is required only when starting the inverter, and the voltage drop caused by this resistor during operation poses a problem, so that it is short-circuited by a short-circuit contact 58 during operation. In the case of an inverter, the above-described electromagnetic contactor shown in FIG. 10 is used as the shorting contact 58.

An example of such an inverter circuit configured with wiring on a printed circuit board is a ``semiconductor circuit device'' disclosed in Japanese Utility Model Application Laid-Open No. 60-83292.

FIG. 12 is a sectional view showing the structure of the semiconductor circuit device disclosed in this publication. In the figure, Figure 1
The same numbers as 1 indicate the same parts. 59 is an inverter base that supports the main circuit components 51, 52, 53, etc. on the inner surface; 60 is a heat dissipation fin that reduces the temperature rise of each component 51 to 53 due to the current of the main circuit; 66 is the main circuit component 5;
1, 52, 53, etc. This is a main circuit wiring board (printed circuit board) with wiring connecting between main circuit components 51, 52, 53, etc.
It is fixed to each terminal 67 such as 53 with a screw 68. 70 is a control circuit wiring board (printed circuit board), and the control device 56
It is electrically and mechanically connected to the main circuit wiring board 66 by a connector 69. 65 is an inverter front cover that closes the opening of the inverter base 59.

Although this publication does not disclose the details of the application form of the electromagnetic contactor, the electromagnetic contactor has a main circuit wiring board 66 shown in FIG.
It is attached to each terminal 67 with a screw 68 in a similar structure.

FIG. 13 is a block diagram showing details of an application form of a conventional electromagnetic contactor. In the figure, 30 is the electromagnetic contactor shown in FIG. 10, and its fixed contacts 9 and 10 include a main circuit terminal board 31 for connecting to a main circuit wiring board 66 located on the upper surface of the electromagnetic contactor. 32 is extended by screwing. Further, coil terminal plates 33 and 34 are similarly extended to the coil terminals 16 and 17. Each terminal board 31-34 is provided with female screws 31a-34a, and a screw 68 is inserted through the main circuit wiring board 66 into the female screws 31a-34a.
4a, the main circuit and excitation coil of the electromagnetic contactor 30 are connected.

[0014]

[Problems to be Solved by the Invention] The conventional electromagnetic contactor 30 connectable to a printed circuit board is constructed as described above, and the main circuit wiring board 66 in FIG. The structure is generally called a power printed circuit board.

FIG. 14 is a perspective view showing the structure of the power printed circuit board, and FIG. 15 is a cross-sectional view taken along line XX. In these figures, 66a is a wiring pattern formed by a normal manufacturing process for printed circuit boards (a pattern manufacturing process by etching a copper-clad laminate). 66b is a wiring conductor made by punching out a good conductor such as a copper plate in substantially the same shape as this wiring pattern 66a, and is electrically and mechanically coupled to the wiring pattern 66a by means such as soldering.
This allows the main circuit current to flow, which is impossible with only the wiring pattern 66a.

Further, 66c is the laminate part of the copper-clad laminate, but since this part is generally a thermosetting resin laminate, heat generated by the main circuit current causes it to wither and shrink in size. It has a nature. That is, the plate thickness t shown in FIG. 15 also becomes smaller. As the plate thickness t becomes smaller, the screw 68 (Fig. 1
3) becomes loose, and the main circuit wiring board 66 and main circuit terminal board 3
The contact resistance with No. 1 and 32 becomes high, and furthermore, there is a risk that this portion will be heated and burn out in the worst case.

Furthermore, although the top surfaces of the main circuit terminal boards 31, 32, etc. must lie within one plane, differences in the height of the terminals may occur due to variations in component manufacturing, or the top surfaces of the main circuit wiring board 66 When it is not parallel to
Similar to the above case, there is a problem in that the contact resistance with the main circuit wiring board 66 becomes high and there is a risk of heating and burning.

[0018] The purpose of the present invention was to solve the above-mentioned problems, which are caused by differences in terminal height due to variations in component processing, inclination of the top surface of the terminal, drying of the printed circuit board, etc. An object of the present invention is to obtain an electromagnetic contactor for connecting a printed circuit board, which can solve the problem of heating due to an increase in contact resistance and maintain reliability of connection to a main circuit wiring board.

In addition to the above-mentioned objects, another object of the present invention is to eliminate steps in terminal height due to variations in component processing, steps in terminal height due to the presence of surge absorber terminals, and steps due to wiring conductors on double-sided power printed circuit boards. To provide an electromagnetic contactor for connecting a printed circuit board, which can be tightened and connected without applying bending force to the printed circuit board, even in such cases.

[0020]

[Means for Solving the Problems] An electromagnetic contactor according to the present invention has terminal screw threading portion sides of a fixed terminal plate and a coil terminal plate arranged horizontally on the upper surface of the case, and the fixed terminal plate and the coil terminal plate are arranged horizontally on the upper surface of the case. A leaf spring is placed on the top of the terminal board.

In the electromagnetic contactor according to the present invention, the terminal screw threaded portion sides of the fixed terminal plate and the coil terminal plate are arranged horizontally on the upper surface of the case, and at least one of the fixed terminal plate and the coil terminal plate is arranged at a terminal height. The terminal has a floating structure so that it can move up and down relative to the height of the other terminal.

[0022]

[Function] In this invention, since a leaf spring is attached to the upper surface of the fixed terminal board and the coil terminal board, the screw-tightened printed board may wither due to temperature rise, and each terminal may have a high terminal height due to variations in parts processing. Even if there is a difference in level or an inclination of the top surface of the terminal, contact reliability can be maintained due to the pressure of the leaf spring.

Furthermore, in the present invention, since at least one of the fixed terminal plate and the coil terminal plate has a floating structure, differences in terminal height caused by variations in component processing and differences in terminal height due to the presence of the surge absorber terminal are avoided. This floating structure absorbs steps caused by wiring conductors on a double-sided power printed circuit board.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. 1 to 3 are configuration diagrams of an electromagnetic contactor according to an embodiment of the present invention, in which FIG. 2 is a top view, FIG. 1 is a sectional view taken along line A-A in FIG. 2, and FIG. 3 is a cross-sectional view taken along line B-B in FIG. A cross-sectional view is shown in each case. In these figures, 1 is a mounting base, 2 is a case, and 3 is an excitation coil. Reference numeral 4 denotes a fixed iron core, which is disposed at a position facing the movable iron core 5 with a predetermined gap therebetween. Reference numeral 6 denotes a crossbar made of an insulating material connected to the movable iron core 5, and slidably holds the movable contactor 8 in the window 6a at the top thereof. Further, in FIG. 1, the cross bar 6 is slidably guided by the case 2 so as to be able to move up and down (not shown).

A contact spring 7 is provided to apply contact pressure to the movable contact 8, and is composed of a compression coil spring. 8a and 8b are movable contacts attached to both ends of the movable contactor 8, and are arranged opposite to the fixed contacts 9a and 10a with a predetermined contact gap.

Fixed terminal plates 109 and 110 have fixed contacts 9a and 10a connected to their U-shaped lower ends, and female screws 109a and 110b formed at their upper ends. The U-shaped upper end surface is arranged horizontally on the upper surface of the case 2,
A leaf spring 120 is attached to its upper surface. Further, the fixed terminal plates 109, 110, the movable contact 8, etc. are arranged in parallel in several pole sets in the main circuit (three poles in this embodiment). 13
is an arc cover, inside which metal arc runners 14 and 15 are fixed, extinguishing the arc generated between the contacts.

Reference numerals 116 and 117 are coil terminal plates, which are approximately U-shaped.
Leads 3a and 3b at the beginning and end of the winding of the exciting coil 3 are connected to 117a. Furthermore, female screws 116b and 117b are formed at the upper end of the U-shape. The U-shaped upper ends of the coil terminal plates 116 and 117 are arranged horizontally on the upper surface of the case, and a leaf spring 121 is attached to the upper surface in the same manner as in the case of the fixed terminal plates 109 and 110. . Further, 20 is a tripping spring, and the combined body of the cross bar 6 and the movable iron core 5 is shown in FIG.
It is arranged so that it is biased to the left at. In FIG. 1, 66 is a main circuit wiring board.

Next, the operation of the embodiment will be explained. Basic operation as an electromagnetic contactor, i.e. ON/O of the excitation coil
The opening/closing operation of the main circuit contacts by the FF is the same as in the conventional example, and the explanation will be omitted here and the connection operation with the main circuit wiring board will be explained with reference to FIG.

The wiring assembly to the main circuit wiring board 66 is completed by tightening the screws 68 to the fixed terminal plates 109, 110 of the main circuit of the electromagnetic contactor through the main circuit wiring board 66. When the leaf springs 120 and 121 are
Assuming that the original height is β and the plate thickness of the leaf spring is T as shown in the figure, the assembly is completed when β is compressed until it becomes equal to T. In other words, the leaf springs 120 and 121 are (β-
With the force required to deform the dimensions of T), the main circuit wiring board 66
It will be assembled in a pressed state.

Therefore, even if the main circuit wiring board dies due to heat generation due to the main circuit current and its thickness t becomes smaller, the amount of reduction in the board thickness Δt will fall within the range Δt<(β−T). For a while, the pressure of the leaf spring acts as contact pressure, and the main circuit's fixed terminal plates 109, 110 and coil terminal plates 116, 1
The connection (contact) between 17 and main circuit wiring board 66 is maintained normally.

Furthermore, due to manufacturing variations in parts, the fixed terminal plates 109 and 110 of the main circuit and the coil terminal plates 116 and 11
Even when there is a step difference in the height of the terminals such as No. For example, even if there are steps or inclinations, these are absorbed by the spring deformation, so that the connection (contact) with the main circuit wiring board 66 is maintained normally.

FIG. 4 is a perspective view showing an example of the configuration of a leaf spring. In the figure, the leaf spring 120 has two protrusions 120a, 1
20b, and is configured to contact and energize the main circuit wiring board 66 at this portion. It goes without saying that the configuration of the leaf spring in this figure is similarly applied to the leaf spring 121.

By increasing the contact points between the leaf springs 120, 121 having such a configuration and the main circuit wiring board 66,
The effect of the leaf spring on the inclination of each terminal described above becomes even more pronounced.

5 to 8 are configuration diagrams of an electromagnetic contactor according to another embodiment of the present invention, FIG. 6 is a top view, and FIG. 5 is a top view.
FIG. 7 is a sectional view taken along line BB in FIG. 6, and FIG. 8 is a sectional view showing how it is connected to a power printed circuit board. Descriptions of parts that are the same as those of the above-described embodiments will be omitted, and differences will be mainly explained.

The U-shaped upper end surfaces of the fixed terminal boards 109 and 110 are arranged horizontally on the upper surface of the case, and their height (terminal height of the fixed terminal board) is the H1 dimension shown in the figure. . In addition, the coil terminal plates 116, 117 are slidably guided by the arc cover 13 so as to be vertically movable in FIG. Floating springs 71 and 72 made of compression coil springs are disposed between 117c and the receiving portions 13a and 13b of the arc cover 13. Due to these, the height H of the upper end surface of the coil terminal plates 116, 117
2 is the terminal height H of the fixed terminal boards 109 and 110 of the main circuit.
1, it has a floating structure that can be moved within the range of H2=[H1-α] to [H1+α]. Note that α is a floating dimension. The terminal height of [H1-α] is the terminal position indicated by the dashed line in FIG. 5, and the terminal height can be moved up and down between these positions.

Next, the operation of this embodiment will be explained with reference to an example of how it is coupled to the power printed circuit board shown in FIG. In FIG. 8, the main circuit wiring board 66 is a double-sided board because the patterns intersect, and the main circuit fixed terminal boards 109, 11
This example shows an example in which a step in terminal height is required between 0 and the coil terminal plates 116 and 117.

FIG. 9 is a sectional view showing an example of the structure of a patterned printed circuit board in such a case. Main circuit wiring board 66
Wiring patterns 66a, 66c and wiring conductor 66 on both sides of
b, 66d are arranged. That is, since the patterns intersect, a double-sided substrate is used. In the example shown in this figure, a wiring conductor 66b for the main circuit is provided on the upper surface, and a wiring conductor 66d for the excitation coil is provided on the lower surface.

As described above, the power printed circuit board requires a step in terminal height between the fixed terminal board of the main circuit and the coil terminal board, and the terminal height H1 of the fixed terminal boards 109 and 110 of the main circuit is required. A step corresponding to the plate thickness t of the wiring conductor 66d is required between the terminal height H2 of the coil terminal plates 116 and 117. Since the above floating dimension α is set to be sufficiently larger than this plate thickness t, even in such a case, the coil terminal plates 116 and 117 will lower to accommodate the above step and tighten with the screw 68. Normal assembly is possible without applying bending force to the printed circuit board.

In the examples shown in FIGS. 8 and 9, the main circuit wiring board 66 is a double-sided board with a main circuit wiring conductor 66b arranged on the upper surface and a wiring conductor 66d for the excitation coil arranged on the lower surface. However, the same effect can be achieved in the opposite way, that is, with a double-sided board in which the main circuit wiring conductor is placed on the bottom surface and the excitation coil wiring conductor is placed on the top surface.

There is also a surge absorber terminal board (not shown) between the coil terminal boards 116, 117 and the main circuit wiring board 66, and a main circuit board between the fixed terminal board of the main circuit and the main circuit wiring board. The above-mentioned floating structure absorbs the difference in level when a terminal board (not shown) of a circuit surge absorber is interposed, or the difference in dimensions of components such as the coil terminal board and the fixed terminal board, and the same can be achieved. Needless to say, it is effective.

In the embodiments shown in FIGS. 5 to 8, the coil terminal plates 116 and 117 have a floating structure, but the effect is the same if the fixed terminal plates 109 and 110 of the main circuit are made to be floating structures. Furthermore, the terminals of both the coil terminal plates 116, 117 and the fixed terminal plates 109, 110 of the main circuit may be made into a floating structure, in which case the effect of absorbing the level difference will be even greater, and the degree of freedom will be greater.

Furthermore, the leaf springs of the embodiments shown in FIGS. 1 to 4 may be applied to the embodiments shown in FIGS.

[0043] In the above embodiment, the terminal of an electromagnetic contactor is described, but it can also be applied to the terminal part of other devices such as solid state contactors, power relays, diode modules, transistor modules, capacitors, etc. This is possible, and by performing these steps, the reliability of the entire device using a power printed circuit board can be improved.

[0044]

[Effects of the Invention] As described above, according to the present invention, a leaf spring is disposed on the upper surface of the fixed terminal board and the coil terminal board, and thereby conducts electricity through contact with the main circuit wiring board (printed board). Therefore, it is possible to prevent unevenness and inclination of the terminal height due to variations in component processing, unstable contact due to withering of the main circuit wiring board (printed board) due to energization, and burnout of the main circuit wiring board due to this. Further, as described above, a highly reliable electromagnetic contactor that can be connected to the main circuit wiring board by screw tightening can be provided, and wiring labor can be saved, so that the entire device can be made inexpensive.

Furthermore, according to the present invention, at least one of the fixed terminal plate and the coil terminal plate is configured to have a floating structure so that it can be moved up and down. This floating structure can absorb differences in terminal height due to intervening terminals and differences in wiring conductors on double-sided power printed circuit boards, reducing contact resistance with the main circuit wiring and suppressing temperature rise at the contact area. In addition, wiring can be assembled by tightening screws without applying bending force to the main circuit wiring board (printed circuit board). Therefore, the device can be manufactured at low cost and reliability is improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along the line AA in FIG. 2 showing the top surface of an electromagnetic contactor according to an embodiment of the present invention.

FIG. 2 is a top view of an electromagnetic contactor according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along line BB in FIG. 2;

FIG. 4 is a diagonal diagram showing a configuration example of a leaf spring according to an embodiment of the invention.

FIG. 5 is a sectional view taken along the line AA in FIG. 6 showing the top surface of an electromagnetic contactor according to another embodiment of the present invention.

FIG. 6 is a top view of an electromagnetic contactor according to another embodiment of the invention.

FIG. 7 is a sectional view taken along line BB in FIG. 2;

8 is a front view showing an example of how the electromagnetic contactor of the embodiment shown in FIGS. 5 to 7 is coupled to a power printed circuit board; FIG.

FIG. 9 is a sectional view showing a configuration example of a power print.

FIG. 10 is a sectional view showing the configuration of a conventional electromagnetic contactor.

FIG. 11 is a circuit diagram of an inverter showing an example of a location where an electromagnetic contactor is used together with a power printed circuit board.

FIG. 12 is a sectional view of a semiconductor circuit device disclosed in Japanese Utility Model Application Publication No. 60-83292.

FIG. 13 is a side sectional view showing a state in which the electromagnetic contactor of FIG. 10 is attached to a power printed circuit board.

FIG. 14 is a perspective view showing the structure of a power printed circuit board to which an electromagnetic contactor is combined.

FIG. 15 is a sectional view taken along line XX in FIG. 14;

[Explanation of symbols]

2; Case 3; Exciting coil 3a; Exciting coil lead portion 3b; Exciting coil lead portion 4; Fixed iron core 5; Movable iron core (electromagnet device) 9a, 10a; Fixed contacts 109, 110; Fixed terminal plates 109b, 110b; Terminal screw screw attachment parts 116, 117; Coil terminal plates 116b, 117b; Terminal screw screw attachment parts 1 of coil terminal plates
20,121; leaf spring

Claims (2)

[Claims] 1. An electromagnet device having an excitation coil, a contact device that is driven to open and close by the electromagnetic device, a fixed terminal plate having a fixed contact of the contact device at one end and a terminal screw threaded portion at the other end, and In an electromagnetic contactor in which a lead portion of the excitation coil is connected to one end and a coil terminal plate having a terminal screw threaded portion at the other end is housed in a case and attached,
An electromagnetic device characterized in that the terminal screw threaded portion sides of the fixed terminal plate and the coil terminal plate are arranged horizontally on the upper surface of the case, and a leaf spring is arranged on the upper surface of the fixed terminal plate and the coil terminal plate. contactor. 2. An electromagnetic device having an excitation coil, a contact device driven by the electromagnetic device to open and close, a fixed terminal plate having a fixed contact of the contact device at one end and a terminal screw threaded portion at the other end, and In an electromagnetic contactor in which a lead portion of the excitation coil is connected to one end and a coil terminal plate having a terminal screw threaded portion at the other end is housed in a case and attached,
The terminal screw threaded portion sides of the fixed terminal plate and the coil terminal plate are arranged horizontally on the upper surface of the case, and the terminal height of at least one of the fixed terminal plate and the coil terminal plate is relative to the terminal height of the other terminal. An electromagnetic contactor characterized by having a floating structure so that it can be moved up and down.