JP2009054489A - Discharge lamp lighting device, and lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device and a lighting fixture easy to install and capable of acquiring a high heat dissipation property. <P>SOLUTION: The discharge lamp lighting device 10 includes a printed circuit board 11 having a lighting circuit formed for supplying lighting power to a circular fluorescent lamp, and a rectangular-parallelepiped case 12 housing the printed circuit board 11 and mounted on a fixture main body 1. A total length of the case 12 is formed to be a dimension or less kept into contact with an inscribed circle inscribed with a globe mounting tool arranged on an under surface of the fixture main body 1, and a width dimension in the lateral direction of the printed circuit board 11 is formed to be 100 mm or more. The printed circuit board 11 maintains its end on the case 12 wherein an upper side is a soldering surface in a use state and a lower side is a component mounting surface, a surface mounting component 21 necessary for heat dissipation is arranged on the soldering surface of the printed circuit board 11, a medium 18 for heat dissipation which thermally combines both the surface mounting component 21 and the case 12 is interposed between the surface mounting component 21 and the inside of the case 12, and the surface mounting component 21 is mounted on a peripheral edge of the printed circuit board 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a discharge lamp lighting device and a lighting fixture.

  Conventionally, as a heat dissipating means for a surface-mounted component mounted on a solder surface of a printed wiring board, a foaming heat dissipating resin is filled between an electronic component and a metal case, and the electronic component is inserted through the filling resin. There has been a method of dissipating heat to the case (see, for example, Patent Document 1).

In the wiring board housing device disclosed in Patent Document 1, the solder surface of the printed wiring board is separated from the insulating sheet disposed on the inner surface of the case within a specific range where the surface mount components that require heat dissipation are disposed. A foamable heat-dissipating resin was filled in between, and heat was radiated to the metal case through this heat-dissipating resin.
JP 2004-274018 A (paragraphs [0029]-[0036] and FIGS. 1 to 3)

  However, when the above-mentioned heat dissipating means disclosed in Patent Document 1 is applied to a discharge lamp lighting device attached to a fixture body to which an annular fluorescent lamp is mounted, this type of discharge lamp lighting device is close to the fluorescent lamp. The temperature inside the discharge lamp lighting device tends to rise due to the influence of the heat generated by the fluorescent lamp. Therefore, in order to suppress the temperature rise inside the lighting device, the volume of the lighting device tends to increase.With the increase in the size of the lighting device, the external dimension of the printed wiring board housed inside becomes 100 mm or more, Since the printed wiring board is warped or bent, there is a possibility that a gap is formed between the insulating sheet and the inner surface of the case, the degree of adhesion between the two is lowered, and the expected heat dissipation effect may not be obtained. In addition, in order to secure a desired heat dissipation effect, it is necessary to improve the adhesion between the insulating sheet and the inner surface of the case. By mechanically fixing the printed wiring board and the case with screws or the like, the printed wiring board Although it is conceivable to suppress warping and bending, there is a problem in that the cost increases due to an increase in the number of assembling steps and parts of the discharge lamp lighting device.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a discharge lamp lighting device and a lighting fixture that are easy to construct and can provide high heat dissipation.

  In order to achieve the above-mentioned object, the invention according to claim 1 is attached to the lower surface side of the instrument main body so as to cover the annular fluorescent lamp and the instrument main body to be attached to the ceiling surface while holding the annular fluorescent lamp. A glove that is attached to the lower surface of the fixture body, and is used for a lighting fixture in which the center of the inscribed circle inscribed in the glove fixture arranged on the circumference is aligned with the center of the fixture body. An electric lamp lighting device, comprising a printed wiring board on which a lighting circuit for supplying lighting power to an annular fluorescent lamp is formed, and a rectangular parallelepiped case for storing the printed wiring board, the entire length of the case being an inscribed circle The printed wiring board is formed to have a width dimension in the short direction of 100 mm or more, and the printed wiring board has a soldering surface on the upper side and a component mounting surface on the lower side in the use state, and the end portion is a case. Let me hold In addition, a surface mount component that needs to dissipate heat is placed on the solder surface of the printed wiring board, and a heat dissipating medium is interposed between the surface mount component and the inner surface of the case, and the surface The mounting component is mounted on the peripheral portion of the printed wiring board.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the winding component is mounted on the peripheral portion of the printed wiring board on the component mounting surface of the printed wiring board.

  Invention of Claim 3 is a lighting fixture, Comprising: The discharge lamp lighting device of Claim 1 or 2 was comprised, It was characterized by the above-mentioned.

  According to the invention of claim 1, since the case for storing the printed wiring board is disposed inside the inscribed circle inscribed in the glove fixture, the inside of the case becomes hot due to the heat generated by the annular fluorescent lamp, Moreover, since the width dimension in the short direction of the printed wiring board is formed to be 100 mm or more, the printed wiring board is likely to warp or bend, but the printed wiring board is held at the edge of the printed wiring board. Since surface mount components that require heat dissipation are mounted, even if the printed wiring board is warped or bent, it is difficult to create a gap between the heat dissipation medium and the surface mount components. A discharge lamp lighting device can be realized. Also, because the printed circuit board on which surface-mounted components are mounted is less likely to warp or bend, it is less likely to crack the solder, improving the reliability of electrical connections, It is also possible to prevent cracks from occurring on the surface mount component. Furthermore, there is no need to mechanically fix the printed wiring board with screws or the like so that there is no gap between the heat dissipation medium and the surface mount component, so there is no increase in cost due to an increase in assembly steps and parts. Also, there is an effect that construction is easy and cost reduction can be realized.

  According to the invention of claim 2, since a relatively heavy winding component is mounted on the peripheral portion of the printed wiring board, the printed wiring board is less likely to warp or bend due to the weight of the winding component, It is possible to suppress a decrease in the heat dissipation effect due to a decrease in the degree of adhesion between the heat dissipation medium and the surface mount component. In addition, by suppressing the occurrence of warping and bending on the printed wiring board, it is possible to prevent solder cracks and improve the reliability of electrical connections, and also prevent cracks in small surface mount components. There is an effect that can be done.

  According to the invention of claim 3, by using the discharge lamp lighting device of claim 1 or 2, the heat generated by the surface-mounted component that requires heat radiation mounted on the solder surface of the printed circuit board is generated through the case. Since the heat is radiated to the main body, the area of the heat radiating plate can be increased to improve the heat radiation effect, and a more reliable lighting fixture can be realized.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
One Embodiment of the lighting fixture using the discharge lamp lighting device concerning this invention is described based on FIGS.

  FIG. 2 is a bottom view of a lighting fixture A that uses the discharge lamp lighting device 10 of the present embodiment, and shows a metal disc-shaped fixture main body 1 that is attached to the ceiling surface while holding the annular fluorescent lamp La. The discharge lamp lighting device 10 is disposed on the lower surface of the appliance body 1. A socket 2 to which the annular fluorescent lamp La is detachably attached is connected to the discharge lamp lighting device 10 via a cable 16, and lighting power is supplied to the annular fluorescent lamp La via the socket 2. In addition, an adapter 3 connected to a hooking ceiling closet disposed on the ceiling surface is provided at the center of the tool body 1, and by connecting the adapter 3 to the hooking ceiling rosette, the tool body 1 is fixed to the ceiling surface. In addition, commercial power is supplied to the discharge lamp lighting device 10 from the hooking ceiling closet. A dome-shaped glove (not shown) is attached to the lower surface side of the instrument main body 1 so as to cover the annular fluorescent lamp La, and a glove attachment 4 for attaching the glove is provided on the outer periphery of the instrument main body 1. They are arranged on the same circumference. Here, the center of the inscribed circle C1 in contact with the inner side of the globe fixture 4 coincides with the center of the instrument body 1, and the discharge lamp lighting device 10 is disposed inside the inscribed circle C1. The case of the discharge lamp lighting device 10 may be arranged at any position as long as it is inside the inscribed circle C1. For convenience of mounting, the case of the discharge lamp lighting device 10 is rotated from the state shown in FIG. It may be arranged in any direction.

  FIG. 3 is a schematic exploded perspective view of the discharge lamp lighting device 10. The discharge lamp lighting device 10 includes a rectangular printed wiring board 11 on which a lighting circuit for supplying lighting power to the annular fluorescent lamp La is formed; A rectangular parallelepiped case 12 for storing the printed wiring board 11 is provided.

  The case 12 is made of a metal bottom case 14 having side walls 14b erected from the four circumferences of the rectangular bottom wall 14a (see FIGS. 5 and 6), and has a substantially box shape with an open top surface. And a metal lid case 13 that is attached to the bottom case 14 so as to cover the bottom (see FIGS. 1 and 3), and the inside of the case 12 is a cross-section that covers the inner surface of the bottom case 14 A U-shaped insulating sheet 15 is mounted. Further, substantially E-shaped cutouts 14c (shaded portions in FIG. 6B) are formed at the left and right end portions of both side walls 14b along the longitudinal direction of the bottom case 14, so that end portions of the printed wiring board 11 are formed. Each pair of holding claws 14d, 14d is formed with a gap therebetween. In the present embodiment, the pair of holding claws 14d are provided at the four corners of the bottom case 14, but the number of the holding claws 14d may be increased or decreased depending on the size and weight of the printed wiring board 11.

  In this discharge lamp lighting device 10, the insulating sheet 15 is attached to the bottom case 14, the solder surface of the printed wiring board 11 is faced upward, and the heat dissipation medium 18 is disposed on the upper side of the surface mount component 21 that requires heat dissipation. The printed wiring board 11 is inserted into the bottom case 14, the pair of holding claws 14d and 14d provided on the side wall 14b of the bottom case 14 are bent inward, and the printed wiring board 11 is placed between the pair of holding claws 14d and 14d. The printed wiring board 11 is held by the bottom case 14 by pinching. Thereafter, the lid case 13 is covered from the lower side of the bottom case 14, and the cable 16 to which the socket 2 is connected is led out of the case 12 from the notch 13 a provided on the side wall of the lid case 13 to complete the assembly. In this assembled state, the heat dissipation medium 18 is interposed between the inner surface of the bottom case 14 and the surface mounting component 21 via the insulating sheet 15, and the metal case 12 (consisting of the lid case 13 and the bottom case 14). The surface mount component 21 is thermally coupled to the surface mount component 21 via the heat dissipation medium 18. As the heat radiation medium 18, for example, a conventionally known heat radiation resin or heat transfer sheet filled between the bottom case 14 and the surface mount component 21 may be used.

  As shown in FIG. 2, the entire length of the case 12 is formed to be equal to or smaller than the dimension in contact with the inscribed circle C1. On the other hand, as shown in FIG. 4, the printed wiring board 11 housed in the case 12 has a width dimension W1 in the short direction of 100 mm or more, and its outer dimension is, for example, 237 mm × 106 mm. Yes. In addition, the width dimension W1 in the short direction of the printed wiring board 11 is smaller than the dimension W2 in the longitudinal direction, that is, the dimension obtained by subtracting the plate thickness of the case 12 from the total length of the case 12 (below the dimension in contact with the inscribed circle C1). Set to dimensions.

  The printed wiring board 11 has a soldering surface 11a on the upper side (the upper side in FIGS. 1 and 3 in FIG. 1 and FIG. 3) in use, a component mounting surface 11b on the lower side, and an end between the holding claws 14b and 14b. It is stored in the case 12 while being held. Further, a surface mount component 21 that needs to dissipate heat is mounted on the solder surface 11a of the printed wiring board 11. As the surface mount component 21 that requires heat dissipation, a diode for rectifying a commercial power source, a countermeasure for harmonic distortion, and the like. Switching devices (such as MOSFETs) and diodes. Between the surface mount component 21 and the inner surface of the bottom case 14, a heat dissipation medium 18 formed in a rectangular plate shape with a material having thermal conductivity is interposed via an insulating sheet 15. Heat generated by the mounting component 21 is radiated to the case 12 through the heat dissipation medium 18 and the insulating sheet 15. In the present embodiment, the surface-mounted component 21 that needs to be dissipated is mounted on the solder surface 11a of the printed wiring board 11 so as to approach the peripheral edge held by the bottom case 14.

  By the way, there is a possibility that the printed wiring board 11 is warped or bent due to the influence of heat. In particular, when the printed wiring board 11 is made of a paper phenolic material, the longitudinal direction of the printed wiring board 11 is the fiber direction ( In the direction D1) in FIG. 4, in the direction perpendicular to the fiber direction D1 (short direction), the warp is caused by the temperature change during solder dipping, the temperature change during use, or the weight of the electronic component mounted on the component surface. It is easy to generate and bend.

  Generally, when the planar shape of the printed wiring board 11 is rectangular, it is known that one side has a length of 100 mm or more, and warping and bending can be prevented by setting the longitudinal direction to the fiber direction. However, if the length in the short direction is 100 mm or more, warping and bending are likely to occur, and not only the rectangular printed wiring board 11 but also the polygonal printed wiring board 11 has the same tendency.

  Table 1 shows data confirming the occurrence of warping and bending when the short dimension of the printed wiring board 11 is 100 mm or more. Actually, four types of printed wiring boards 11 made of paper phenol are actually used. Flow soldering was performed through a solder dip bath.

  In these printed wiring boards 11, the warp of the substrate was prevented by setting the longitudinal direction to be perpendicular to the fiber direction, and it was confirmed from what size the warp direction is the same as the fiber direction. From the results of Table 1, it was found that in the case of the printed wiring board 11 having a short dimension of 122 mm or more, there is a high possibility of warping, and it is necessary to take measures to prevent warping. The present inventors have determined that warping occurs in the case of the printed wiring board 11 having a short dimension of 100 mm or more with a margin from this result. In the example of Table 1, the warp prevention bar is arranged in the center of the printed wiring board 11 in the direction parallel to the longitudinal direction to prevent the warp. In the case of the printed wiring board 11 that has been warped, there is a case where there is not enough space for mounting components in order to put a warpage prevention bar, and there are cases where measures for preventing warpage cannot be taken.

  In the present embodiment, a heat dissipation medium 18 and an insulating sheet 15 are interposed between the surface mounting component 21 mounted on the solder surface side of the printed wiring board 11 and the bottom case 14, and the surface mounting component 21. The generated heat is radiated to the metal bottom case 14 via the heat radiating medium 18 and the insulating sheet 15, and further radiated to the metal instrument body 1 to which the case 12 is attached. When the length in the short direction is 100 mm or more, there is a high possibility that the printed wiring board 11 is warped or bent, and the bottom case is formed on the solder surface 11a of the printed wiring board 11 as shown in FIG. 14, when the surface mounting component 21 is mounted in the center of the printed wiring board 11 far from the end held by the area 14 (the area surrounded by the dotted line in FIG. 7B), the surface of the printed wiring board 11 is warped or bent. Mounting parts 1 and a gap is formed between the radiating medium 18, that both the degree of adhesion decreases, not desired heat dissipation effect. Further, the warping or bending of the printed wiring board 11 may cause a decrease in reliability of electrical connection due to a crack in the solder portion, a crack in a small surface mount component, or the like.

  Therefore, in the present embodiment, as shown in FIG. 7A, the peripheral portion of the printed wiring board 11 (the region surrounded by the dotted line in FIG. 7A), which is held by the bottom case 14 Even if the printed wiring board 11 is warped or bent, the surface mounted component 21 is placed in a place where it is difficult to form a gap with the heat radiating medium 18 due to warping or bending. Since it is mounted, it is possible to suppress a decrease in heat dissipation performance. Therefore, there is no need to fix the printed wiring board 11 to the case 12 with screws or the like in order to suppress warping or bending of the printed wiring board 11, and the printed wiring board 11 is held by the holding claws 14d provided on the bottom case 14. To provide a discharge lamp lighting device that does not incur high costs due to an increase in assembly man-hours and parts, is easy to construct, can be reduced in cost, and has high heat dissipation. it can. Further, since the surface mount component 21 is mounted on the peripheral portion of the printed wiring board 11, cracks and the like are hardly generated in the solder, the reliability of electrical connection can be improved, and a small surface mount component 21 is provided. It is also possible to prevent cracks from occurring.

  As shown in FIG. 8, on the solder surface 11 a of the printed wiring board 11, the surface-mounted component 21 that needs to dissipate has a radius a from the holding claw 14 d of the bottom case 14 that holds the end of the printed wiring board 11. It is more desirable to implement within the range. As a result of experiments conducted by the inventors changing the radius a, the temperature of the surface-mounted component 21 gradually increased when the radius a exceeded 30 mm, and increased by 5 ° C. on average at the radius a = 50 mm. On the other hand, when the radius a is within 30 mm, it was confirmed that a desired heat dissipation effect was obtained.

  In the lighting fixture A of the present embodiment, the heat generated by the surface mount component 21 that needs to be radiated is radiated to the metal case 12 via the heat radiating medium 18 and the insulating sheet 15, and further from the case 12. Since the heat is radiated to the metal fixture body 1, the area of the heat radiating plate can be increased to improve the heat dissipation effect, and the lighting fixture A with higher reliability can be realized.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a cross-sectional view of a main part of a lighting fixture A using the discharge lamp lighting device 10 according to the present invention. In the discharge lamp lighting device 10 used in the lighting fixture A described in the first embodiment, the components of the printed wiring board 11. The winding component 22 mounted on the mounting surface 11 b is mounted close to the peripheral edge of the printed wiring board 11 whose end is held by the bottom case 14. In addition, since it is the same as that of the discharge lamp lighting device 10 and the lighting fixture A described in the first embodiment except for the arrangement of the winding component 22, common constituent elements are denoted by the same reference numerals and description thereof is omitted. .

  As described in the first embodiment, the printed wiring board 11 is held by the bottom case 14 at the end, and when a heavy winding component 22 is mounted at the center of the printed wiring board 11, the winding The central portion of the printed wiring board 11 bends due to the weight of the component 22, and a gap between the surface-mounted component 21 disposed on the solder surface side and the heat dissipation medium 18 becomes large, so that a sufficient heat dissipation effect may not be obtained. There is sex. In addition, the flexure of the printed wiring board 11 may cause cracks in the solder and reduce the reliability of electrical connection, or may cause cracks in the small surface mount component 21.

  Therefore, in the present embodiment, a heavy weight winding component 22 is mounted on the peripheral portion of the printed wiring board 11 on the component mounting surface 11b of the printed wiring board 11, and is wound around a portion held by the bottom case 14. By arranging the wire component 22, the bending of the printed wiring board 11 is suppressed. FIG. 10 shows a specific example of the printed wiring board 11. In this embodiment, as the winding component 22 having a relatively heavy weight, a common mode filter 22a using a ferrite core, high frequency choke coils 22b and 22c, and a high frequency transformer 22d are used. , 22e. The weights of these components are, for example, about 20 g for the common mode filter 22a, about 50 g for the high frequency choke coils 22b and 22c, about 25 g for the high frequency transformer 22d, and about 15 g for the high frequency transformer 22e, and these winding components 22a to 22e. Is mounted on the peripheral portion of the printed wiring board 11, so that the bending of the printed wiring board 11 can be reduced and the degree of adhesion between the surface mount component 21 and the heat dissipation medium 18 can be suppressed from decreasing. Further, the winding components 22a to 22e are held by the holding claw 14d of the bottom case 14 in the vicinity of the peripheral portion of the printed wiring board 11 and held by the holding claw 14d of the bottom case 14. It is preferable to arrange within the range of the radius a from the part, and the printed wiring board 11 can be further prevented from being bent by the weight of the winding components 22a to 22e. Specifically, the radius a is within 40 mm. Is more desirable.

  As described above, in the present embodiment, the winding component 22 is disposed on the peripheral portion of the printed wiring board 11 held by the bottom case 14, so that the printed wiring board 11 is not mechanically fixed with screws or the like. Further, since the bending of the printed wiring board 11 can be suppressed and the gap formed between the heat dissipation medium 18 and the surface mount component 21 can be reduced, the reduction of the heat dissipation effect can be suppressed, and solder cracks can be prevented. It is possible to improve the reliability of the general connection and to prevent the small surface mount component 21 from cracking. Moreover, since it is not necessary to mechanically fix the printed wiring board 11 with a screw etc., construction is easy and cost reduction is realizable.

  Further, the heat generated by the surface mount component 21 that needs to be dissipated is radiated to the metal case 12 through the heat radiating medium 18 and the insulating sheet 15 and further radiated from the case 12 to the metal instrument body 1. Therefore, the area of the heat radiating plate can be increased to improve the heat radiating effect, and a more reliable lighting fixture A can be realized.

  It should be noted that a wide variety of different embodiments can be configured without departing from the spirit and scope of the present invention, and the present invention is not limited to a specific embodiment.

It is sectional drawing of the principal part of the lighting fixture of Embodiment 1. FIG. It is a bottom view of the state which showed the lighting fixture same as the above and removed the glove. It is a disassembled perspective view of the discharge lamp lighting device used for the same as the above. It is a top view of the discharge lamp lighting device used for the same as the above. The bottom case of the discharge lamp lighting device used for the above is shown, (a) is a plan view, (b) is a top view, (c) is a bottom view, and (d) is a right side view. The bottom case of the discharge lamp lighting device used for the same as above is shown, (a) is a principal part enlarged perspective view showing a holding part of a printed wiring board, and (b) is a principal part enlarged side view. (A) (b) is explanatory drawing explaining the component arrangement | positioning of the printed wiring board used for the same as the above. It is explanatory drawing explaining the component arrangement | positioning of the printed wiring board used for the same as the above. It is sectional drawing of the principal part of the lighting fixture of Embodiment 2. FIG. It is a top view of the printed wiring board of the discharge lamp lighting device used for the same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Instrument body 4 Globe attachment 11 Printed wiring board 12 Case 13 Cover case 14 Bottom case 15 Insulation sheet 18 Heat radiation medium 21 Surface mount component A Lighting fixture La Annular fluorescent lamp

Claims (3)

An instrument main body that is attached to the ceiling surface while holding the annular fluorescent lamp, and a glove that is attached to the lower surface side of the instrument main body so as to cover the annular fluorescent lamp, and the glove is attached to the lower surface of the instrument main body A discharge lamp lighting device used for a lighting fixture in which the center of an inscribed circle inscribed in a glove fixture arranged on the circumference is aligned with the center of the fixture body,
A printed wiring board on which a lighting circuit for supplying lighting power to the annular fluorescent lamp is formed, and a rectangular parallelepiped case that houses the printed wiring board,
The overall length of the case is formed to be equal to or smaller than the dimension in contact with the inscribed circle, and the width dimension in the short direction of the printed wiring board is formed to be 100 mm or more. The lower side is the component mounting surface, the end is held in the case, and a surface-mounted component that requires heat dissipation is placed on the solder surface of the printed wiring board, and both are heated between the surface-mounted component and the case inner surface. A discharge lamp lighting device, characterized in that a heat-dissipating medium to be coupled is interposed, and the surface-mounted component is mounted on a peripheral portion of the printed wiring board.   The discharge lamp lighting device according to claim 1, wherein a winding component is mounted on a peripheral portion of the printed wiring board on a component mounting surface of the printed wiring board.   A lighting fixture comprising the discharge lamp lighting device according to claim 1.

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