JP2009193437A - Programmable controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform electrical connection reliably in a plate for ground connection in a configuration in which a plurality of circuit boards are accommodated in a housing. <P>SOLUTION: In the housing (a lower case 4) of a programmable controller, a plurality of circuit boards 23 are arranged horizontally side by side in a manner that they stand with their longitudinal direction facing the front-back direction. A metallic common plate 10 for ground connection is disposed on the inner bottom of the lower case 4, and a plurality of individual plates 11 are also disposed for electrically connecting the common plate 10 with the ground pattern of each circuit board 23. A connection part 16 that is electrically connected to the ground pattern of the circuit board 23, and an elastic contact strip 19 that elastically contacts the circuit board 23 are provided to each of the individual plates 11 in an integrated manner. A line contact part at the root portion of the elastic contact strip 19, two point contact parts on its right and left sides, and a plane contact part that contact the common plate 10 are also provided to each of the individual plates 11 in an integrated manner. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a programmable controller configured by housing a plurality of circuit boards in a housing.

  For example, a programmable controller (I / O module) that is used in factory equipment and performs input / output control for external devices, for example, a control circuit and an input / output circuit section are mounted in a rectangular box-shaped plastic casing. Electrical connection to external equipment (for example, motors, belt conveyors, electromagnetic valves, display devices, loads such as lamps, input equipment such as switches and sensors) on the front surface of the housing, for example It is configured with a connector and a terminal block for performing the above.

  The programmable controller is configured such that the back side of the casing is attached to the back side in the control panel by screwing or supported by a DIN rail provided on the wall of the facility. At this time, a metal plate called an FG plate that is electrically connected to the ground pattern of the circuit board is provided on the inner wall surface of the housing, and the FG plate is externally connected via, for example, a screw. It is electrically connected to (the frame of the control panel or the DIN rail) and is set to the ground potential (grounded).

  By the way, in this kind of programmable controller, in recent years, it is conceivable to enlarge the housing and provide a plurality of circuit boards therein, that is, to consolidate a plurality of modules (units) into one. ing. In such a large programmable controller, the FG plate extends over the entire inside of the casing in order to connect all the ground patterns of a plurality of circuit boards to the ground. In addition, a plate (connection fitting) may be provided for each circuit board.

In this case, a connection portion that is electrically connected (contacted) to the ground pattern of the circuit board and a contact piece that is contacted to the FG plate are integrally provided on the individual plate (connecting metal fitting). It will be. In this type of connection fitting, the contact piece is curved so as to have a spring property, and a protrusion is integrally provided at the center (contact portion) of the contact piece, and the protrusion is attached to the FG plate by a spring force. By making the surface elastically contact with the surface of the plate, it is possible to achieve reliable contact of the contact piece with the FG plate (see, for example, Patent Document 1).
Japanese Utility Model Publication No. 61-161970

  However, as described above, in the structure in which the protrusion is provided on the contact piece of the connection metal fitting and the protrusion is brought into contact with the FG plate, the connection metal fitting and the FG plate are in point contact at only one point. If the spring property of the contact piece deteriorates, or if dirt (impurities) is generated on the surface of the portion where the projection of the FG plate contacts, there is a possibility that the electrical connection becomes insufficient. Therefore, when a common FG plate for ground connection and individual plates for each circuit board are provided in a large casing, reliable electrical connection between each individual plate and the common plate is ensured. It becomes a problem to do.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to accommodate a plurality of circuit boards in a housing and reliably perform electrical connection in a ground connection plate. There is a need to provide a programmable controller.

  In order to achieve the above object, a programmable controller of the present invention is configured by housing a plurality of circuit boards in a housing, and a common plate for ground connection is provided in the housing. In addition, a plurality of individual plates for electrically connecting the common plate and the ground pattern of each circuit board are provided, and each individual plate is electrically connected to the ground pattern of the circuit board. A connecting portion, a surface contact portion that is in contact with a part of the surface of the common plate, an elastic contact piece that elastically contacts an edge of the circuit board, and a base portion of the elastic contact piece. It is characterized in that it is configured by integrally forming a line contact portion that makes line contact with the surface of the common plate by forming a bent portion.

  According to this, the ground pattern of each circuit board is grounded via each individual plate and the common plate with which the individual plate contacts in common. At this time, each individual plate is brought into line contact with the surface of the common plate so that the line contact portion at the base portion of the elastic contact piece is pressed by the circuit board, and at the same time, is brought into surface contact with the surface contact portion. In this way, contact (electrical connection) is achieved at a plurality of locations by the line contact portion and the surface contact portion, so that bending deformation of the individual plates, deterioration of the spring property of the elastic contact pieces, a part of the surface of the common plate Even if contact is obstructed in part due to dirt or the like, contact between the individual plate and the common plate can be ensured in other parts.

  In the programmable controller of the present invention, each individual plate can be further provided with a plurality of point contact portions that make point contact with the surface of the common plate at a predetermined position (invention of claim 2). The predetermined position means a portion where the common plate and the individual plate overlap. Further, at this time, at least one of the elastic contact pieces in the width direction may be provided with a point contact portion having a pointed shape and a tip of which is in point contact with the surface of the common plate (invention of claim 3). According to these, in addition to the contact by the line contact portion and the surface contact portion, the individual plate is point-contacted at a plurality of points by a plurality of point contact portions with respect to the common plate. Even if it is done, it will become more excellent by the function which ensures a contact in another part, and it will become more effective by ensuring the contact with respect to the common plate of an individual plate.

  According to the programmable controller of the present invention, a plurality of circuit boards are accommodated in a housing, and a common plate for ground connection is provided in the housing, and the common plate and each circuit board are provided. A plurality of individual plates for electrically connecting the ground pattern are provided, and each of the individual plates has a plurality of contact portions (surface contact portions, line contact portions, and point contact portions) that contact the surface of the common plate. Since it was provided, the excellent effect that electrical connection in the plate for ground connection can be reliably performed can be obtained.

  Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. First, FIG. 7 shows an appearance of the programmable controller 1 (I / O module) according to the present embodiment. The programmable controller 1 is used in, for example, factory facilities and performs input / output control for external devices (for example, motors, belt conveyors, electromagnetic valves, display devices, loads such as lamps, input devices such as switches and sensors). It is. The programmable controller 1 is used in combination with other modules (a CPU module, a power supply module, another I / O module, etc.) as necessary.

  The programmable controller 1 includes a plurality of (for example, six) circuit boards 23 (for example, six boards) in which a control circuit, an input / output circuit unit, and the like are mounted in a synthetic resin casing 2 having a horizontally long rectangular box shape as a whole. 1 only one is shown). At this time, the housing 2 is configured by combining an upper case 3 and a lower case 4 (see FIGS. 1, 3 and 4), and the circuit board 23 is placed in the lower case 4 as will be described later. It can be assembled. In addition, a terminal block 5 (or connector) to which a cable (wiring) of an external device is connected is provided on the front side in the figure of the housing 2. A display unit 6 is provided on the front surface (upper surface in FIG. 1) of the housing 2 (upper case 3) for displaying the operation status of the external device by turning on / off the LED.

  For example, the programmable controller 1 is attached to a wall surface in a control panel (or rack) by being screwed or supported by a DIN rail. At this time, on the lower surface side (lower case 4) of the housing 2 as shown in FIGS. 3 and 4, the screw is positioned at the left and right ends of the rear side of the lower case 4 and at the three central portions. As shown in FIG. 4, the screwing portion 7 having the insertion hole 7 a is integrally provided, and as shown in FIG. 4, the engaging groove portion 8 extends to the entire bottom surface of the lower case 4 and can be engaged with the DIN rail. Is formed.

  The programmable controller 1 (each circuit board 23) is connected to a ground potential (earth) via the frame of the control panel or the DIN rail. Note that the programmable controller 1 may be assembled to the control panel with the surface having the engagement groove 8 as the back surface, that is, it may be disposed with the upper surface side as the front surface in FIG. The direction in FIG.

  1, 3 and 4 show the structure of the lower case 4. FIG. Here, the lower case 4 as a whole has a rectangular box shape with the upper surface (and the upper portion of the front surface) opened, and the dimension in the front-rear direction inside thereof substantially matches the length dimension of the circuit board 23. The plurality of circuit boards 23 are arranged such that both front and rear edge portions are supported on the inner surfaces of the front and rear wall portions of the lower case 4 in a state where the longitudinal direction is directed forward and backward, and are arranged side by side in the left-right direction. .

  At this time, as shown in part in FIGS. 1 and 3, the circuit boards 23 are inserted into the inner surface portions of the front and rear walls of the lower case 4 from above so that the circuit boards 23 are held. A recessed groove 9 is provided. These insertion grooves 9 extend in the vertical direction and are provided in a form in which the upper end is opened, but the insertion part of the upper end part is configured to expand slightly upward. These insertion grooves 9 are formed with a height (length) as required.

  As shown in FIGS. 1 to 3, a metal common plate 10 for ground connection is provided on the inner bottom of the housing 2 (lower case 4), and the common plate 10 and each circuit board 23 are provided. A plurality of (in this case, six) individual plates 11 are provided for electrically connecting the ground pattern (not shown). The common plate 10 and the individual plate 11 are formed, for example, by punching a metal thin plate with a press and performing predetermined bending (cutting up).

  Among them, the common plate 10 has a narrow plate shape extending in the left-right direction as a whole along the rear side of the inner bottom surface of the lower case 4 as shown in FIGS. 1, 3, and 6. . And as shown in FIG. 6, the screwing piece part 12 which has the screw insertion hole 12a and protrudes toward back is integrally provided in the right-and-left both ends and center part of the common plate 10. As shown in FIG. At the same time, on the front side of the common plate 10, a plurality of convex piece portions 13 that are convex forward are integrally provided.

  As shown in FIGS. 1 and 3, the common plate 10 is configured such that each screwing piece 12 is inserted into a first slit 4 a formed in the lower case 4 corresponding to the three screwing parts 7. Mounted. Thereby, each screwing piece part 12 (screw insertion hole 12a) comes to wrap in each screwing part 7 (screw insertion hole 7a) of the lower case 4, and screwing is made in the screwing part 7. Thus, an electrical connection (earth connection) between the common plate 10 and the outside is achieved via a screw so as to be a ground potential. Each convex piece 13 is provided corresponding to each individual plate 11 (circuit board 23). As will be described later, each individual plate 11 (rear side 11b described below) is overlaid on the upper surface thereof. In this state, electrical connection (contact) is made.

  As shown in FIGS. 1, 3, and 5, each individual plate 11 includes a front side part 11 a, a rear side part 11 b, a left side part 11 c, and a right side part 11 d so as to surround the opening as a whole. It has a substantially rectangular frame shape in which the right half portion of the front side portion 11a protrudes forward, and further includes the following portions as a single piece.

  That is, as shown in FIG. 5, the left side portion 11c has a shape in which the left side edge portion is bent downward, and the left insertion piece 14 is integrally provided. In addition, the rail contact piece 15 which is located on the left side portion, extends forward, and is bent upward so as to bend downward is integrally formed on the front side of the front side 11a. Is provided.

  Further, as shown in FIG. 2A, two front and rear connection portions 16 that are electrically connected to the ground pattern of the circuit board 23 are integrally provided along the edge portion on the opening side (left side). It has been. These connecting portions 16 are bent so as to rise (raise) upward, and the upper side is bent into a front-like shape so that springiness is imparted, and the bent portion of the character-like shape is provided. The circuit board 23 is elastically contacted (pressure contact) with the ground pattern. Further, as shown in FIG. 5, the right side portion 11d has a right insertion portion 17 whose right side edge portion is bent downward, and two curved shapes located on the front and rear sides thereof. The spring portion 18 is integrally provided.

  At this time, as shown in FIG. 3 and the like, the bottom wall portion of the lower case 4 has a second slit 4b into which the left insertion piece 14 of each individual plate 11 is inserted, and the right insertion portion 17 and A third slit 4c into which the spring portion 18 is inserted is formed extending in the front-rear direction, and a through hole 4d into which the rail contact piece portion 15 is inserted is formed. Each individual plate 11 has a left insertion piece 14 inserted into the second slit 4b from the upper surface side of the bottom wall portion of the lower case 4, and a right insertion portion 17 and a spring portion 18 inserted into the third slit 4c. The contact piece 15 is attached to the lower case 4 by being inserted into the through hole 4d.

  As a result, the left insertion piece 14 is inserted into the second slit 4b, and the right insertion portion 17 and the two spring portions 18 are inserted into the third slit 4c and elastically fitted. Thus, the individual plate 11 is attached without rattling, and as a result, the connection portion 16 comes into contact with the ground pattern of the circuit board 23 with certainty. Further, as shown in FIG. 4, the rail contact piece 15 is positioned in an exposed state so as to face the engagement groove 8 through the through hole 4d. Thus, at the time of mounting using the DIN rail, the rail contact piece 15 comes into contact with the DIN rail and is electrically connected (set to the ground potential).

  The rear side portions 11 b of the individual plates 11 are positioned so as to be overlaid (placed) on the convex piece portions 13 of the common plate 10. At this time, as shown in FIG. 2, FIG. 5, etc., the end of the circuit board 23 is inserted into the insertion groove 9 and attached to the rear side 11b near the right end. An elastic contact piece 19 that elastically contacts the edge (lower edge) is integrally provided, and three types of contact parts that contact the surface (upper surface) of the common plate 10 (convex piece 13) are provided integrally. It is done.

  That is, as shown in FIG. 2B and the like, the elastic contact piece 19 is formed in a form in which a square part is obliquely raised along the opening side (front side) edge of the rear side part 11b. Yes. The base portion of the elastic contact piece 19 is a bent portion that extends linearly in the left-right direction, and the lower surface side of the bent portion is in contact with the line contact portion 20 that makes line contact with the surface of the common plate 10. Has been. And the edge part of the opening side (front side) of the rear side part 11b is located in two places on the left and right sides of the elastic contact piece 19, has a sharp shape resembling a bird's beak, and the tip is slightly downward. A point contact portion 21 that makes point contact with the surface of the common plate 10 is formed. Further, the other portions of the rear side portion 11 b are surface contact portions 22 that are in contact with each other so as to overlap a part of the surface of the common plate 10 (the convex piece portion 13).

  In the above-described configuration, a plurality of circuit boards 23 are accommodated in the housing 2 (lower case 4). A common plate 10 for ground connection is provided on the inner bottom of the lower case 4, and A plurality of individual plates 11 for electrically connecting the ground pattern of the circuit board 23 and the common plate 10 are provided. At this time, each individual plate 11 includes a connection portion 16 that is electrically connected to the ground pattern of the circuit board 23, an elastic contact piece 19 that elastically contacts the circuit board 23, and the common plate 10 (convex). The line contact portion 20 at the base portion of the elastic contact piece 19, the two point contact portions 21, and the surface contact portion 22 that are in contact with the piece portion 13) are integrally provided.

  Thus, each individual plate 11 is in line contact with the surface of the common plate 10 such that the line contact portion 20 at the base portion of the elastic contact piece 19 is pressed by the circuit board 23, and at the same time, two points A plurality of types of contact portions such as the contact portion 21 and the surface contact portion 22 make contact (and thus electrical connection) with the common plate 10 at a plurality of locations. Therefore, even if the individual plate 11 is bent and deformed, the spring property of the elastic contact piece 19 is deteriorated, or a part of the surface of the common plate 10 is soiled, the contact cannot be ensured in part. The contact with the common plate 10 can be ensured in the other parts of the eleven.

  As described above, according to the programmable controller 1 of the present embodiment, the housing 2 is configured to accommodate a plurality of circuit boards 23, and the ground connection common plate 10 and the individual plates 11 There is an excellent effect that electrical connection between the two can be reliably performed. In particular, in the present embodiment, since the two point contact portions 21 are provided on both sides of the line contact portion 20 (elastic contact piece 19), it is more effective to ensure the contact of the individual plate 11 with the common plate 10. It becomes.

  FIG. 8 shows another embodiment of the present invention, and shows the configuration of the main part of the individual plate 31. Also in this embodiment, the rear side portion 31 b of the individual plate 31 is positioned so as to be overlaid (placed) on each convex piece portion 13 of the common plate 10. The individual plate 31 (rear side portion 31b) is integrally provided with the elastic contact piece 19, and the line contact portion 20 and the surface contact portion 22 that are in contact with the surface of the common plate 10 (convex piece portion 13). It has been. Then, on the opening side (front side) portion of the rear side portion 31b, point contact portions 32 are formed which are located at two positions on the left and right sides of the elastic contact piece 19 and project downward.

  Even in such a configuration, as in the above-described embodiment, each individual plate 31 has the surface of the common plate 10 such that the line contact portion 20 at the base portion of the elastic contact piece 19 is pressed by the circuit board 23. Along with this, contact with the common plate 10 (and thus electrical connection) is achieved at a plurality of locations by a plurality of types of contact portions such as the two point contact portions 32 and the surface contact portion 22. Therefore, this embodiment also has an excellent effect that the electrical connection between the common plate 10 for ground connection and each individual plate 31 can be reliably performed.

  The present invention is not limited to the embodiments described above and shown in the drawings. For example, in each of the embodiments described above, one individual plate 11, 31 is provided for one circuit board 23. Although provided, it may be provided so that one individual plate is shared with two adjacent circuit boards. In this case, two sets of connection portions and elastic contact pieces (line contact portions) are provided on one individual plate. In addition, various changes can be made to the shape and structure of the housing, the number of circuit boards accommodated, and the number of point contact portions 21 and 32 may be one, or three or more. The present invention may be implemented with appropriate modifications within a range that does not depart from the gist of the invention.

The perspective view of the lower case which shows one Example of this invention and fractures | ruptures and shows the right half part The perspective view (a) of the principal part of one individual plate, and the perspective view (b) which expands and shows the elastic contact piece part Lower case plan view Perspective view of the lower case upside down Perspective view of individual plate Top view of common plate A perspective view showing the appearance of a programmable controller FIG. 2 (b) equivalent view showing another embodiment of the present invention.

Explanation of symbols

  In the drawings, 1 is a programmable controller, 2 is a housing, 4 is a lower case, 7 is a screwing portion, 8 is an engaging groove, 9 is a insertion groove, 10 is a common plate, 11 and 31 are individual plates, and 13 is convex. One part, 16 is a connection part, 19 is an elastic contact piece, 20 is a line contact part, 21 and 32 are point contact parts, 22 is a surface contact part, and 23 is a circuit board.

Claims (3)

A programmable controller configured by housing a plurality of circuit boards in a housing,
In the case, a common plate for ground connection is provided, and a plurality of individual plates for electrically connecting the common plate and the ground pattern of each circuit board are provided,
Each of the individual plates includes a connection portion that is electrically connected to a ground pattern of the circuit board, a surface contact portion that is in contact with a part of the surface of the common plate, and an edge portion of the circuit board. An elastic contact piece that elastically contacts the surface of the common plate, and a line contact portion that makes line contact with the surface of the common plate by forming a bent portion obtained by bending the base portion of the elastic contact piece. A programmable controller characterized by   2. The programmable controller according to claim 1, wherein each of the individual plates is further provided with a plurality of point contact portions that make point contact with the surface of the common plate at predetermined positions.   3. The programmable controller according to claim 2, wherein at least one of the elastic contact pieces in the width direction is provided with a point contact portion that has a pointed shape and a tip of which makes point contact with the surface of the common plate.

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