JP5578438B2 - Shield case, equipment using the same, and image forming apparatus - Google Patents

Description

  The present invention relates to a box-shaped shield case in which a printed circuit board is disposed and has electromagnetic non-interference and resistance, and an apparatus such as an image forming apparatus using the box-shaped shield case.

  In image forming apparatuses such as copying machines, printers, facsimiles, and multi-function machines, when a shield case for mounting a printed circuit board and a shield cover for sealing the printed circuit board are designed, it can be opened and closed by a service operation or the like. It is known that electromagnetic non-interference and tolerance for clearing the EMC test are required.

  However, with this type of conventional image forming apparatus, it is difficult to design a shield case and shield cover that can be opened and closed, and does not leak electromagnetic waves to the outside, and is not affected by electromagnetic waves, so it is difficult to design a screw. The use of a large number eliminates the gap and improves the electrical conductivity, but the use of a large number of screws increases the man-hours during the production.

  FIG. 7 is an external view of the shield case main body 1 and the shield cover 2 of the shield case conventionally employed, and FIG. 8 is a perspective view showing a conventional fixing method. As shown in the drawing, conventionally, the shield cover 2 is fixed to the edge of the shield case body 1 with a large number of screws 11 to reduce the gap.

  For example, Patent Document 1 discloses that the periphery of a shield case is aimed at reducing the cost of parts while ensuring electrical continuity, reducing the number of screw fastenings, and reducing the number of assembly steps. And a shield structure with a spring contact member interposed therebetween, the shield cover having a plurality of protrusions and hook structure hooks on the periphery of the shield cover, and the shield cover protruding on the periphery of the shield case. A relief contact hole is provided, and an engagement hole is formed to slide the hook hook to engage. The spring contact member is sandwiched between the shield case and the shield cover, and the spring part is pushed by the convex part of the shield cover. The structure which bends in the clearance hole of this and obtains electrical continuity is disclosed.

  However, the problem that a gap is formed between the engagement surfaces of the shield case main body and the shield cover has not been solved.

  Therefore, an object of the present invention is to eliminate the gap between the shield case main body and the shield cover and attach the shield cover to the shield case main body easily.

  The shield case according to claim 1 of the present invention is a box-shaped shield case having an opening surface on one surface of the shield case body and having a printed circuit board disposed inside, inside the opening surface of the shield case body. A shield cover that is inserted into the shield case, and a parallel motion mechanism that is disposed on each of two opposing side surfaces other than the opening surface of the shield case main body, and the shield cover is bent at least 90 degrees downward. A lower link of the parallel motion mechanism is an L-shaped member for receiving the bent portion of the shield cover, and the parallel motion mechanism includes upper and lower links and the shield case main body. A bracket that is positioned opposite the opening surface, and a spring that pushes up and biases the link below the link on the lower side of the parallel motion mechanism, The lower link of the parallel motion mechanism is pushed up by the spring force so that the shield cover is sandwiched between the bracket of the parallel motion mechanism and the inner surface of the edge of the opening surface of the shield case body. It is characterized by that.

  According to the second aspect of the present invention, in the shield case of the first aspect, the shield case main body has an elongated hole for inserting the shield cover therein.

  According to a third aspect of the present invention, in the shield case of the first or second aspect, the bracket is made of metal.

  According to a fourth aspect of the present invention, in the shield case of the first or second aspect, the bracket is made of a non-metal.

  According to the fifth aspect of the present invention, in the shield case of the third or fourth aspect, a metal leaf spring is attached to a contact surface of the bracket with the shield cover.

  According to the sixth aspect of the present invention, in the shield case of the third or fourth aspect, a shield gasket is attached to a contact surface of the bracket with the shield cover.

  According to a seventh aspect of the present invention, there is provided a device comprising the shield case according to any one of the first to sixth aspects as an apparatus housing.

  According to an eighth aspect of the present invention, there is provided an image forming apparatus characterized in that the shield case according to any one of the first to sixth aspects is used in an apparatus housing.

  According to the present invention, there is no gap between the shield case body and the shield cover, and the shield cover can be easily attached to and removed from the shield case body.

A view of the shield case from the side, showing the link open A view of the shield case from the side, showing the link closed Perspective view inside shield case 1 is an external view of a shield case and a shield cover according to an embodiment of the present invention. The figure which showed the attachment position of the leaf | plate spring to the cover presser in one Example of this invention. Figure showing the position of the shield gasket attached to the cover holder External view of conventional shield case and shield cover Diagram showing how to fix a conventional shield case and shield cover

  In a box-shaped shield case that has a printed circuit board inside, and can be easily attached as an alternative to screws in a box-shaped shield case for electromagnetic incoherence and resistance, the cover is placed under its own weight. When the inside of the case is slid, a bent bracket having an L-shaped cross section receives the cover, and the cover is pressed against the inside of the case by the link mechanism. That is, use the weight of the shield cover to activate a parallel movement mechanism such as a parallel crank mechanism arranged in the shield case, and press the shield cover against the inner edge of the shield case body with the bracket attached to the link. Thus, the shield cover can be easily attached to and removed from the shield case body without a gap between the shield case body and the shield cover.

<Example 1>
Embodiments of the present invention will be described below with reference to the drawings.
The shield case shown in FIG. 1 shows the arrangement of components before the shield cover 2 is inserted from the long hole 1 a on the upper surface of the shield case main body 1 and the lower end of the shield cover 2 gets on the first link 3. In the shield case main body 1, it arrange | positions in the both sides | surfaces (FIG. 1 shows only one side surface) which the link mechanism mentioned later opposes.

  Since the link mechanism is the same on both sides, only the mechanism on one side shown in the figure will be described. The first link 3 is a member having a cross-sectional shape bent at 90 degrees, and is received by the coil spring 6 from below and urged upward. The first shaft 4 and the third shaft 8 are attached to the side surface of the shield case body 1 by caulking, and these shafts 4 and 8 serve as the rotation centers of the first link 3 and the second link 7, respectively. The spring 6 can be replaced with another elastic member.

  At the other end of the first link 3 and the second link 7, the upper and lower bent portions 10a of the cover presser 10 (which is a metal bracket) that holds the shield cover 2 between the second shaft 5 and the fourth shaft 9 are held. doing. Since two bending portions 10a are provided for each link mechanism arranged on both side surfaces of the shield case body 1, although not shown, there are a total of four bending portions 10a. The cover retainer 10 is a plate material having a size larger than the opening surface of the shield case main body 1, and a square hole 10x is formed at the center for work. The shield cover 2 is sandwiched between the cover retainer 10 and the periphery of the opening 1x of the shield case body 1, and the cover retainer 10 and the shield cover 2 are overlapped to ensure a contact area. However, before the shield cover 2 is placed on the first link 3, the first link 3 is lifted by the coil spring 6, and there is a gap between the cover presser 10 and the shield cover 2, and the shield cover 2 is inserted. At times, it plays the role of a guide plate.

  The shield cover 2 has bent portions 2a and 2b in the upper and lower sides. The lower bent shape portion 2b is a portion for riding on the first link 3, and has a size that can be inserted through the long hole 1a on the upper surface of the shield case main body 1. The upper bent shape portion 2a is for preventing the shield cover 2 from falling into the shield case body 1, and is larger (or longer) than the long hole 1a on the upper surface of the shield case body 1 at least. 1 is formed so as to overlap with the upper surface of 1. A screw hole 2as is formed in the upper bent shape portion 2a, and a screw hole 1as is also formed in the shield case main body 1 so as to correspond thereto.

  In FIG. 2, the shield cover 2 rides on the first link 3 in the shield case main body 1, the first link 3 rotates clockwise, and the shield cover 2 is sandwiched between the cover presser 10 and the inner edge of the shield case main body 1. 2 shows the arrangement of each component when it moves to the lowest side. When the first link 3 receives the lower end of the shield cover 2, the first link 3 rotates clockwise around the first shaft 4, and the cover presser 10, which is a follower, is displaced toward the shield case body 1, and from a certain point in time. Press the shield cover 2 against the shield case body 1.

  The link mechanism for performing the above-described operation is the parallel crank mechanism of the illustrated example (however, the present invention is not limited to this mechanism, and a known parallel motion mechanism can be used instead), and the link mechanism of the facing link The length is equal. That is, the deformation is performed while maintaining the shape of the parallelogram. In the illustrated mechanism, the shield cover 2 is pressed against the shield case body 1 side by the cover presser 10 as the shield cover 2 is pushed in from above. Moreover, since the position of the 1st axis | shaft 4 and the 3rd axis | shaft 8 is parallel with respect to the edge surface inside the opening part of the shield case main body 1, the cover holding | suppressing 10 also becomes parallel similarly. For this reason, the shield cover 2 can be pressed by the cover presser 10 with an equal force. The upper bent shape portion 2a of the shield cover 2 is attached to the upper surface of the shield case body 1 with screws 11 and fixed so that the shield cover 2 does not lift.

  FIG. 3 is a perspective view of the link mechanism described above. The first shaft 4 and the third shaft 8 are attached to the side surface of the shield case body 1 by caulking. Since the cover presser 10 is attached to the first link 3 and the second link 7, the cover presser 10 has four corners at right angles to the cover presser 10 and parallel to the first link 3 and the second link 7.

  FIG. 4 is an external view of the shield case main body 1 and the shield cover 2 of the present embodiment. Since the shield cover 2 and the shield case body 1 can be pressed against the shield case body 1 by the above-described parallel crank mechanism, the shield cover 2 can be pressed from above as described above. It is only necessary to stop with the screw 11 so that it does not come off.

<Example 2>
FIG. 5 shows a second embodiment of the present invention, specifically, an example in which the leaf spring 12 is attached to the cover presser 10. In the present embodiment, the plurality of leaf springs 12 are attached to the surface of the cover presser 10 on the shield cover 2 side by pasting or the like to improve conductivity. Since the range in which the leaf spring 12 is provided is to apply a uniform force to the shield cover 2, it is preferable to arrange the cover spring 10 evenly over the entire edge around the square hole 10 x of the cover presser 10. The leaf spring 12 can be replaced with another elastic member.

<Example 3>
FIG. 6 shows a third embodiment of the present invention, specifically, an example in which a shield gasket is attached to the cover presser 10. In this embodiment, the shield gasket 13 is attached to the surface of the cover presser 10 on the shield cover 2 side to improve the conductivity. Since the range in which the shield gasket 13 is provided is to apply a uniform force to the shield cover 2, a form in which the shield gasket 13 is disposed evenly over the entire edge around the square hole 10 x of the cover presser 10 is preferable.

<Example 4>
Although illustration is omitted, the above-described shield case has a printed circuit board disposed inside such as an image forming apparatus, and can be employed as a structure of a device that requires electromagnetic non-interference and resistance. is there.

1: Shield case 1a: Long hole 1as on the top surface of the shield case: Screw hole 1x: Opening of the shield case 2: Shield cover 2a, 2b: Bending shape portion 2as of the shield cover: Screw hole 3: First link 4: First Axis 5: Second axis 6: Coil spring 7: Second link 8: Third axis 9: Fourth axis 10: Cover press 10a: Cover press bending portion 10x: Cover press square hole 11: Screw 12: Leaf spring 13 : Shield gasket

JP 2005-19862 A JP-A-11-163575

Claims (8)

In a box-shaped shield case that has an opening on one side of the shield case body and the printed circuit board is placed inside,
A shield cover to be inserted inside the opening surface of the shield case body;
A parallel motion mechanism disposed on each of two opposing side surfaces other than the opening surface of the shield case body, and
The shield cover has a bent portion bent at least 90 degrees downward;
The lower link of the parallel motion mechanism is an L-shaped member for receiving the bent portion of the shield cover,
The parallel motion mechanism has upper and lower links and a bracket positioned to face the opening surface of the shield case body,
A spring that pushes up and biases the link is disposed below the link below the parallel motion mechanism,
The lower link of the parallel motion mechanism is pushed up by the bias of the spring, and the shield cover is sandwiched between the bracket of the parallel motion mechanism and the inner surface of the edge of the opening surface of the shield case body. ,
Shield case characterized by that. The shield case of claim 1,
The shield case main body has an elongated hole on the top surface for inserting the shield cover into the inside.
Shield case characterized by that. The shield case according to claim 1 or 2,
The bracket is made of metal,
Shield case characterized by that. The shield case according to claim 1 or 2,
The bracket is non-metallic,
Shield case characterized by that. The shield case according to claim 3 or 4,
A metal leaf spring is attached to the contact surface of the bracket with the shield cover.
Shield case characterized by that. The shield case according to claim 3 or 4,
A shield gasket is attached to the contact surface of the bracket with the shield cover.
Shield case characterized by that.   An apparatus comprising the shield case according to any one of claims 1 to 6 as an apparatus housing. An image forming apparatus using the shield case according to claim 1 for an apparatus housing.