JP2600269B2 - Temperature control section protection case - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a temperature control section protection case such as an electric blanket.

2. Description of the Related Art As shown in FIG. 8, a conventional temperature control unit protection case of an electric warming device, for example, a temperature control controller of an electric blanket, has a flat plate in an internal space formed by combining a case A2 and a case B3. The printed circuit board 4 is placed on the case B3 side so that the front surface 5 on which the electronic components are mounted comes, and on the case A2 side, the back surface 6 on which the copper foil pattern is drawn comes. In addition, 7 is a knob.

The printed circuit board 4 has a case as shown in FIG.
With several ribs 14 protruding inside A2, case A2
And the case B3. Therefore, a gap 4a exists between the ribs 14.

Problems to be Solved by the Invention Normally, an electric blanket controller is used near a futon where dust such as cotton dust is likely to be generated, and is used in a place where dust easily accumulates such as on a tatami mat. As shown in FIG. 10, dust enters inside through a gap 7a between the case B3 and the knob 7, and easily accumulates on the inner bottom surface of the case A2 through the gap 4a.

Also, since the controller 1 itself is not fixed,
The placement is not uniform. For example, when the case B3 is placed on the tatami 8 side as shown in FIG. 11, all the dust accumulated on the bottom surface of the case A2 shown in FIG. Since it adheres to the back surface 6 of the printed circuit board 4, the distance between the copper foils on the back surface 6 is restricted by 2.5 mm or more based on the Electrical Appliance and Material Control Law, and the size of the printed circuit board 4 becomes large, and therefore the controller 1 itself becomes large. There is a problem that the usability is deteriorated.

In order to prevent dust from entering the controller,
For example, if a method such as embedding packing made of rubber or the like between the case A2 and the printed board 4 shown in FIG. Back side 6 according to law
However, the distance between the copper foils may be 1.5 mm or more, and the size of the printed circuit board 4 can be reduced, and the size of the controller can be reduced. However, there is a problem that the cost increases instead.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a compact and inexpensive temperature control unit protection case that prevents dust from entering.

Means for Solving the Problems In order to solve the above problems, the temperature control section protection case of the present invention has a flat printed board, and a flat section at the bottom receiving the outermost perimeter of a specific area on the back surface of the printed board. And a case B having, at predetermined intervals, projections for pressing the entire outermost periphery of a specific area on the back surface of the printed circuit board from the surface of the printed circuit board to the flat portion of the case A, and the projections of the case B are printed. A plurality of projections are provided at a predetermined interval on the case B so that a small gap is formed in the peripheral fitting surface between the case A and the case B at the time of contact with the surface of the substrate due to the thickness of the printed circuit board. The printed circuit board is pressed and brought into close contact with the flat portion of the case A by the protrusion of the case B when the peripheral fitting surface of the B contacts.

Operation According to the above configuration, when the printed circuit board is installed inside and the case A and the case B are combined, the printed circuit board is pushed toward the case A by the projection of the case B. The entire outer periphery is in close contact with the plane portion of the case A provided corresponding thereto. Moreover, the force by which the protrusion of the case B pushes the printed circuit board is due to the compressive stress generated when the case A and the case B are combined. Is always in close contact with the plane portion of the case A provided so as to correspond thereto.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In particular, the upper and lower embodiments will be described with reference to an electric blanket controller. The same components as those of the conventional example are denoted by the same reference numerals.

FIG. 1 is a cutaway perspective view of an electric blanket controller according to an embodiment of the present invention. A flat portion 9 is provided in a case A2 so as to receive a back surface 6 of a printed circuit board 4. As shown in FIG. 2 and FIG. 3, the outer periphery 10 of the specific area on the back surface 6 of the printed circuit board 4 is received. Note that the specific area is an area in which dust is not desired to enter, and is a part of the printed board in the present embodiment, but may be the entire printed board in some cases.

In FIG. 1, reference numeral 3 denotes a case B, and a projection 11 is provided so as to press the printed board 4 in the direction of the case A2.
As shown in FIG. 4, they are provided at predetermined intervals so as to correspond to the entire outermost periphery 10 of the specific region on the back surface 6 of the rear panel 6. FIG. 5 shows the projection
FIG. 11 is an enlarged view of FIG. 11, and a conical dowel 12 is provided at a tip of a protrusion 11. In this embodiment, the conical dowel is used, but a pyramid dowel such as a triangle or a square may be used. In addition, as shown in FIG. 6, the length of the protrusion 11 is determined before the fitting surfaces 13 around the case A2 and the case B3 come into contact with each other in consideration of variations due to shrinkage during molding and variations during assembly. The conical dowel 12 is set so as to hit the surface 5 of the printed circuit board 4.

In this way, when the fitting surfaces 13 around the case A2 and the case B3 come into contact with each other as shown in FIG. 7, the protrusion 11 is brought into contact with the front end of the conical dowel 12 against the surface 5 of the printed circuit board 4. A compressive stress of the degree of crushing is generated, and the printed board 4 is pushed toward the case A2 by the repulsive force,
The entire outer periphery 10 of the specific area on the back surface 6 of the printed circuit board 4 is in close contact with the flat portion 9 of the case A2. Therefore, the specific area of the back surface 6 of the printed circuit board 4 is shut off from the outside air, so that no dust enters, and accordingly, the back surface 6 according to the Electrical Appliance and Material Control Law.
The distance between the copper foils can be designed to be 1.5 mm or more, and the size of the printed circuit board 4 can be reduced. Therefore, the size of the controller 1 itself can be reduced at the same cost as the conventional one, and the usability is improved. .

Effect of the Invention As described above, the present invention provides a flat printed board, a case A having a flat portion that receives the entire outer periphery of a specific area on the back surface of the printed board, A case B having projections for pressing the entire circumference on the plane portion of the case A from the surface of the printed circuit board at predetermined intervals, and the periphery of the case A and the case B when the projections of the case B abut on the surface of the printed circuit board; A plurality of projections are provided at a predetermined interval on the case B so that a gap smaller than the thickness of the printed circuit board is formed on the fitting surface. With a simple configuration of pressing and adhering on the flat portion of the case A, it is possible to prevent intrusion of dust, reduce the size of the printed circuit board and the temperature control unit protection case, and improve the usability. .

[Brief description of the drawings]

FIG. 1 is a cutaway perspective view of a temperature control unit protection case showing one embodiment of the present invention, FIG. 2 is a plan view of a case A of the protection case, FIG. FIG. 4 is a plan view of the case B of the protective case, FIG. 5 is an enlarged perspective view of a protrusion of the case B of the protective case, and FIGS.
FIG. 8 is a cross-sectional view showing the fitted state of the protective case, FIG. 8 is a cutaway perspective view of the conventional temperature control unit protective case, FIG. 9 is a plan view of case A of the protective case, and FIG. FIG. 11 is a sectional view of the case, and FIG. 11 is a side view showing a state of use of the protective case. 2 Case A, 3 Case B, 4 Printed circuit board, 6 Back surface, 9 Plane portion, 11 Projection.

Claims (4)

(57) [Claims] 1. A case A having a flat printed circuit board, a flat portion at the bottom for receiving the outermost entire periphery of a specific region on the back surface of the printed circuit board, and an outermost entire periphery of a specific region on the back surface of the printed circuit board. And a case B having projections for pressing the surface of the printed circuit board from the surface of the printed circuit board at predetermined intervals on the flat surface of the case A, and the case B and the case B are fitted around the case B when the projection and the surface of the printed circuit board come into contact with each other. A plurality of projections having a predetermined interval are provided on the case B so as to generate a gap smaller than the thickness of the printed board on the mating surface, and the printed board is brought into contact with the case B when the surrounding fitting surfaces of the case A and the case B contact each other. A temperature control section protection case that is pressed and brought into close contact with the flat portion of the case A with a projection. 2. A structure according to claim 1, wherein the specific region on the back surface of the printed circuit board is shielded from the outside air by a flat portion that receives the outermost periphery of the bottom surface of the case A and the specific region on the back surface of the printed circuit board. Temperature control section protection case. 3. The temperature control section protection case according to claim 1, wherein the projection of the case B has a conical dowel at a tip end thereof. 4. The temperature control section protection case according to claim 1, wherein the projection of the case B has a pyramid-shaped dowel at a tip end thereof.