JPH0731507Y2 - Grounding structure of electronic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a grounding structure of an electronic device, and more specifically, it is applied to an input unit, an output unit, a CPU unit, etc. which constitute a programmable controller, for example. The present invention relates to a particularly effective ground structure of an electronic device.

[Prior Art] FIG. 7 is a perspective view of an example of a conventional programmable controller (hereinafter referred to as a PC). In the figure, 1 is a box-shaped case made of a synthetic resin material and having a front opening, 2 is a power supply unit which is inserted into the case 1 and whose front panel is screwed to the case 1, and 3 is adjacent to the power supply unit 2. The front panel is a CPU unit screwed to the case 1, and the control program setting unit 5 (hereinafter referred to as "setting program") having the connector 6 connected to the connecting portion 4 of the CPU unit 3 is provided on the power supply unit 2 and the CPU unit 3. Is called a vessel,
It is fixed by screws. Reference numeral 7 is an input unit, 8 is an output unit, and the front panel is screwed to the case 1 in parallel with the CPU unit 3.
Terminal board 9 connected to the controlled object on the front panel of 7,8
And a signal display portion 10 are provided, and a printed wiring board 11 having a connector connected to a signal line of a motherboard (not shown) provided at the bottom of the case 1 is attached to the back surface of the front panel. There is. In order to suppress noise from the outside, these printed wiring boards are usually connected to the ground wiring provided on the motherboard.

In the PC having the above-mentioned respective parts, the necessary control program is set in advance by the setter 5, and this is stored in the CPU unit 3. The input signal from the control target is added to the input unit 7 and is calculated by the CPU unit 3. The control signal based on the calculation result is output from the output unit 8 and the control target is controlled based on the set value of the setter 5. To do.

[Problems to be solved by the invention] As described above, since the PC has an excellent control function,
Widely used in industry. However, the work of connecting the ground terminals of the input unit and output unit, etc. is troublesome, and especially when these units are mounted in high density, not only will the number of ground terminals increase and the cost will increase, but also the work of connecting them. There was a problem that it took a lot of time.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain a grounding structure for an electronic device, which has a simple structure and can be connected to the grounding terminal with one touch.

[Means for Solving the Problems] An earth structure of an electronic device according to the present invention includes a case main body having slot holes provided at predetermined intervals on a back surface and through holes provided between the slot holes, and the case body. A main body having an engaging hole at a position corresponding to a through hole of the main body, and an outer surface provided with contacts for contacting a mother board and the like, and legs provided at both ends of the main body and inserted into the slot holes of the case main body And a grounding member that is connected to a grounding wiring pattern provided on a printed wiring board that is inserted into the case body and that is located near a through hole of the case body. Fit the leg of the ground terminal fitting into the groove of the case body, and screw the screw inserted into the engaging hole of the ground terminal fitting into the screw hole provided in the ground member through the through hole provided in the case body. I put it in It

[Operation] Insert the leg of the ground terminal fitting into the groove provided on the back surface of the case body, fit the engagement hole into the through hole of the case body, and then insert a screw into the engagement hole to connect the ground member. It is screwed into the screw hole and the ground terminal fitting, screw and ground member are integrally connected.

[Embodiment of the Invention] FIG. 5 is a perspective view of an embodiment of the present invention, in which 21 is a case body and 41
Is a panel attached to the opening of the case body 21, 61 is a display unit provided on the panel 41, 65 is a display plate, and 71 is a cover.

Next, details of the input unit 1a according to the present invention will be described with reference to the exploded perspective view of FIG. In FIG. 6, reference numeral 21 denotes a box-shaped case body having an open front surface, and a large number of ventilation holes 22 are provided on both wall surfaces in the longitudinal direction. Reference numeral 23 is an engaging projection provided on the inner wall of the opening, and 24 is an engaging hole formed below the engaging projection 23. Reference numeral 25 is a guide groove of the printed wiring board provided inside the rear vertical wall. The guide groove may be provided on the front vertical wall or the bottom of the case body 21. In addition,
Reference numerals 27 and 28 denote window holes provided at the bottom of the case main body 21, into which a connector to be attached to a printed wiring board described later and to be connected to a mother board provided on a base board is inserted.

Reference numeral 41 denotes a panel, and guide plates 42 (only one of which is shown in the figure) fitted in the opening of the case body 21 are vertically provided on both sides of the lower surface, and the engaging projections 23 of the case body 21 are provided on the outer surface thereof. A cutting portion 43 that engages and a protrusion 44 that engages with the engagement hole 24 are provided. Although not shown, a printed wiring board is fixed inside the guide plate 42. Reference numeral 45 is a display portion, and a locking piece 46 having a locking claw 47 at its tip is vertically provided at one end. Reference numeral 48 is a display chamber for accommodating a light emitting diode, a numerical display, etc. provided on the upper surface of the display unit 45, a display window 49 is formed on the upper surface, and fitting holes 50 are provided on both side walls. ing. 51 is a display part 45 and a terminal board mounting part described later.
A vertical wall that borders 53 and is lower than the display chamber 48, and the central portion on the display chamber 48 side is cut away to form a recess 52, and a gap g is formed between the display chamber 48 and the display chamber 48. Has been done.
53 is the terminal board mounting part, 54 is the wiring from the terminal board in the case body
It is an elongated hole for taking in 21. 55 is the terminal board mounting part 53
The vertical wall provided at the rear of the
Is provided.

Reference numeral 61 is a display cover made of a translucent material, to which numbers and signals indicating the state of the signal indicated by the display are attached. A locking portion 62 that fits into the fitting hole 50 of the display chamber 48 is provided on the inner side of both side walls, and a cutout hole 63 is formed on the rear vertical wall.
Are formed. Reference numeral 65 is a T-shaped display plate for distinguishing the input unit, the output unit, the CPU unit, and the like, and a projection 66 that fits into the notch hole 63 of the display cover 61 is provided on one surface. A through hole 67 is formed in the upper central portion. The display plate 65 is colored, for example, red, blue, white or the like, and displays the type of each unit.

Reference numeral 71 denotes a cross-section cover, one end of which is provided with a projecting piece 72 which is fitted into the through hole 67 of the display plate 65, and the other end of which is formed as shown in FIG. 6 (b). An engaging claw 74 having elasticity and engaging with a locking hole 56 provided on the vertical wall 55 of the panel 41
Is provided with a locking piece 73.

FIG. 3A is a rear view of the case body 21, and FIG.
-A is an enlarged sectional view. Reference numeral 30 denotes a recess provided on one side of the back surface of the case body 21 (in this embodiment, the display portion 45 side), and a groove is formed between the projections 31 and 31a on the inner surface side of both side walls of the case body 21.
32, 32a are formed, a through hole 33 is provided on one side from the center of the recess 30, and a circular recess 34 is provided on the other side.
Are formed.

4 (a) is an enlarged sectional view of the ground terminal fitting 35, (b).
Is a plan view thereof, and (c) is a side view. This ground terminal fitting 35 is formed by bending the main body 36 and both ends thereof at a substantially right angle,
Legs 3 that are fitted into the slots 32, 32a of the recess 30 of the case body 21
7,37a, and the main body 36 has an inner peripheral edge (legs 37,37a
Side) and the through hole 33 provided in the recess 30 of the case body 21.
And engaging holes 38, 38a are provided at positions aligned with the recess 34. 38b is an inclined surface formed on the inner edge of the engaging holes 38, 38a, 39,
Reference numeral 39a is a contact which is provided so as to project from the outer surface of the main body 36 and which comes into contact with the ground wiring of the motherboard. Reference numerals 40, 40a are locking claws provided on both sides of the leg portions 37, 37a.

In FIG. 1, reference numeral 81 denotes a printed wiring board mounted on the lower surface of the panel 41, and at the position corresponding to the through hole 33 provided in the recess 30 of the case 21 when the printed wiring board is inserted into the case 21, A grounding member 82 connected to a grounding wiring pattern provided on the printed wiring board 81 is attached. 83
Is a screw hole provided in the ground member 82.

Next, an example of the assembly of the present invention configured as described above will be described with reference to FIG.

(1) Insert a numeral display or the like from below into the display portion 45 of the panel 41, position it on the display window 49 and fix it. Next, the display cover 61 is fitted into the display chamber 48. In this case, when the rear vertical wall of the display cover 61 is fitted into the gap g formed by the display 48 and the vertical wall 51 and pressed down, the locking portion 62 engages with the fitting hole 50 and is fixed. .

(2) The leg portion of the display plate 65 is inserted into the recess 52 of the vertical wall 51, and the protrusion 61 is engaged with the cutout hole 63 of the display portion cover 61. At this time, the top of the display plate 65 is located substantially flush with the upper surface of the display cover.

(3) Place a terminal board (not shown) on the terminal board mounting portion 53,
Secure with screws. Further, the printed wiring board 81 (see FIG. 1) is mounted on the lower surface of the panel 41.

(4) The panel 41 to which various parts are attached as described above is attached to the opening of the case body 21. At this time, if the printed wiring board attached to the panel 41 is lowered along the guide groove 25 provided in the case body 21, the protrusion 44 becomes the engaging hole 24 and the cutout 43 becomes the engaging protrusion 23. Engage each,
Further, the locking claw 47 of the locking piece 46 engages with the heat dissipation hole 22, and the two can be integrally combined with one touch.

At this time, the connector provided on the printed wiring board and connected to the connector provided on the motherboard of the base board is exposed to the outside through the window holes 27 and 28 provided at the bottom of the case body 21.

(5) Then, as shown in FIG. 1, the leg portions 37, 37a of the ground terminal fitting 35 are inserted into the groove holes 32, 32a of the recess 30 provided on the back surface of the case body 21, and the engaging holes 38, 38a are inserted. The protruding part of is fitted into the through hole 33 and the recess 34 and positioned. At this time, legs 37, 37a
The locking claws 40, 40a provided on the base plate bite into the side walls of the slots 32, 32a, and the ground terminal fitting 35 is firmly fixed.

In this state, insert a screw 84 into the engagement hole 38 of the ground terminal fitting 35, and screw this screw 84 into the screw hole 83 of the ground member 82 located inside the through hole 33 of the case main body 21 It is fixed integrally.

The state at this time is shown in FIG. As is clear from the figure, the head of the screw 84 is pressed against the inclined surface 38b of the engagement hole 38,
The ground member 82 is electrically and surely connected to the ground terminal fitting 35 via the screw 84.

(6) Finally, by inserting the protruding piece 72 of the cover 71 into the through hole 67 of the display plate 65 and pressing down the other end, the locking piece 74 has a convex locking hole 56.
The cover 71 is joined to the panel 41.

To mount the input unit configured as described above on the base board, the engaging portion 29 provided on the bottom of the case body 21 is engaged with and abuts the hole provided on the base boat, and the heat dissipation hole 22
The screw may be inserted into the hole 26 provided in the lower part of the base and screwed into the screw hole of the base boss.

At this time, the contacts 39, 39a provided on the ground terminal fitting 35 are
As shown in FIG. 2, the printed wiring board 81, the ground member 83, the screw 84, the inclined surface 38b of the engaging hole 38, the ground terminal fitting 35, and the contact are made by contacting the ground pattern (not shown) provided on the motherboard M. An earth circuit including the children 39, 39a and an earth pattern is formed.

In the above description, the case where the present invention is applied to the input unit of the PC has been described. However, the present invention can be applied to the output unit and the like, and can also be applied to other electronic devices.

Further, in the above embodiment, the case where the ground terminal fitting is provided in the end portion on the rear surface of the case body and in the width direction is shown, but it can be provided in an appropriate position depending on the position and shape of the printed board to be installed. .

Furthermore, although a case is shown in which a recess is provided on the back surface of the case body and the ground terminal fitting is fitted into this recess, the recess may be omitted. Further, although the case where the grounding terminal fitting is provided with two engaging holes with the edges protruding inward has been shown, the edge may be only the engaging holes that fit into the through holes of the case body. The number is not limited.

[Advantages of the Invention] As described in detail above, the grounding structure of an electronic device according to the present invention includes a case body having slot holes provided at predetermined intervals on the back surface and through holes provided between the slot holes. , A main body having engaging holes at positions corresponding to the through holes of the case main body and provided with contacts on the outer surface for contacting the mother board and the like, and inserted into the slot holes of the main body of the case provided at both ends of the main body The case consists of a grounding terminal metal fitting consisting of legs, a pudding inserted into the case body, and a grounding member connected to the grounding wiring pattern provided on the wiring board and located near the through hole of the case body. Insert the leg of the ground terminal fitting into the groove of the main body, and screw the screw inserted into the engaging hole of the ground terminal fitting into the screw hole provided in the ground member through the through hole provided in the case body. Since it was an electronic device When the is attached to a motherboard or the like, the ground terminal provided on the motherboard or the like and the ground terminal of the electronic device can be connected with one touch. Therefore, the number of steps for connecting the ground terminal and the cost can be significantly reduced.

Further, since the electrical connection of each part is made by surface contact, the electrical resistance can be stabilized.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention, FIG. 2 is a sectional view showing its assembled state, FIG. 3 (a) is a rear view of an embodiment of a case body which is an essential part of the present invention, and (b). ) Is a sectional view taken along the line A-A, FIG. 4 (a) is a sectional view of the ground terminal fitting which is also an essential part of the present invention, (b) is its plan view, (c) is a side view, and FIG. 5 is A perspective view of an example of an input unit embodying the present invention, FIGS. 6 (a) and 6 (b) are exploded perspective views thereof, and FIG.
The figure is a perspective view showing an example of a conventional programmable controller. 21: Case body, 30: Recess, 32, 32a: Groove hole, 33: Through hole, 3
4: Recess, 35: Ground terminal fitting, 36: Main body, 37, 37a: Leg part, 3
8,38a: Engagement hole, 39, 39a: Probe, 81: Printed wiring board,
82: grounding member, 84: screw.

Claims (1)

[Scope of utility model registration request] 1. A case main body having slot holes provided at predetermined intervals on the back surface and through holes provided between the slot holes, and engaging holes at positions corresponding to the through holes of the case main body. ,
A main body having a contactor for contacting a mother board or the like on the outer surface, and ground terminal fittings made of legs provided at both ends of the main body and inserted into the slot holes of the case main body, and inserted into the case main body Connected to a wiring pattern for grounding provided on a printed wiring board, consisting of a grounding member located in the vicinity of the through hole of the case body, and fitting the leg portion of the ground terminal fitting into the slot hole of the case body, A ground structure for an electronic device, wherein a screw inserted into an engaging hole of the ground terminal fitting is screwed into a screw hole provided in the ground member through a through hole provided in the case body.