Bulb type lamp

The present invention relates to a light bulb type lamp using a light emitting element such as an LED (light emitting diode) as a light source.

It is known that as the temperature of an LED rises, the life of the LED decreases as the light output decreases. Therefore, in a lamp using an LED as a light source, it is required to suppress an increase in the temperature of the LED.

Conventionally, in consideration of such a request, an LED bulb which is provided with a heat radiating portion for releasing heat transmitted from the LED to the outside and the heat radiating portion is exposed to the outside is known (see, for example, Patent Document 1). ..

In the LED light bulb of Patent Document 1, the LED is mounted on the outer surface of a metal substrate provided inside a substantially sphere. The substantially sphere is formed by a metal heat radiating portion having a base provided at one end and forming a trumpet shape toward the opening at the other end, and a translucent cover attached to the opening. The metal substrate is fixed to the opening via an insulating high thermal conductive member.

As a result, the heat generated by the LED while the LED bulb is lit is transferred from the metal substrate to the trumpet-shaped metal heat-dissipating portion via the high heat conductive member, and is discharged to the outside from the outer peripheral surface of the heat-dissipating portion. The temperature rise of the LED can be suppressed.<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2001-243809 (paragraphs 0005, 0011-0013, FIG. 1)</text></patcit>

<p> In the technology of Patent Document 1, the heat radiating portion exposed to the outside of the LED bulb and the metal substrate on which the LED is directly mounted are separate members. Therefore, even though both are fixed via the high heat conductive member, in the heat conductive path from the metal substrate to the heat radiating portion, between the high heat conductive member and the metal substrate, and between the high heat conductive member and the heat radiating portion. Thermal resistance occurs between them. Therefore, there is room for improvement in suppressing the temperature rise of the LED.</p><p> Further, Patent Document 1 does not mention a lighting circuit for lighting an LED. Further, when the lighting circuit is provided in the LED bulb, it is required that the LED bulb does not become large in the axial direction. Further, it is generally known that if the temperature of the lighting circuit rises abnormally, the operation reliability and life of the circuit may be impaired. Therefore, when the lighting circuit is provided in the LED bulb, it is also required that the temperature of the lighting circuit does not rise abnormally. However, these requests cannot be satisfied by Patent Document 1.</p><p> An object of the present invention is to provide a light bulb type lamp capable of effectively suppressing an increase in temperature of a light source and suppressing a decrease in operation reliability and life of a lighting circuit while reducing the size.</p>

<p>In order to solve the above problems, the invention of claim 1 is to mount a light source having a peripheral portion exposed to the outside, a flat outer surface integrally formed with the peripheral portion, and a screw hole opened on the outer surface. A metal outer member having a recess formed inside the peripheral portion and the peripheral portion; a mouthpiece arranged on the opening edge side of the recess; and a plurality of light emitting elements forming a point light source were mounted. The light source substrate, which is a flat plate-shaped light source substrate and is closely fixed to the outer surface of the light source mounting portion so as to conduct heat to the light source mounting portion by a screw screwed into the screw hole: A translucent cover that covers the light source and is attached to the outer member; and a lighting circuit that is formed by attaching circuit components to the circuit board and housed in the recess;<u style="single">It has an opening on the base side and a closed wall portion on the light source mounting portion side with an electric wire through hole.</u>Provided between the inner surface of the recess and the lighting circuit<u style="single">, Accommodating the lighting circuit</u>It is equipped with an insulating member and;</p><p> In the present invention, iron and its alloys, metals having better thermal conductivity such as copper and its alloys, and lighter metals such as iron and its alloys such as aluminum and its alloys are used as the metal forming the outer member. it can. In the present invention, as a configuration for increasing the heat dissipation area of the outer shell member, it is possible to knurl the peripheral portion of the outer shell member to make the outer peripheral surface rough, and instead, a heat dissipation fin is formed. It is also possible to do. Further, the outer peripheral surface of the peripheral portion of the outer member may be coated with a protective film for rust prevention. In this case, if the black protective film is coated, the heat radiation from the outer member to the outside can be further improved. Is preferable. In the present invention, the light source mounting portion integrally formed with the outer shell member may also serve as the back wall of the recess, or is formed by a convex portion extending further in the axial direction from the back wall toward the inner surface of the cover. You can also do it.</p><p> In the present invention, a light emitting element that converts electric energy into light, for example, a light emitting diode (LED), which is also called a semiconductor light emitting element, can be preferably used as the point light source, but an electric luminescence element (EL element) is used. It is also possible to use, and the number of point light sources used is<u style="single">Multiple</u>It should be. With this invention<u style="single">The point light source is on the light source substrate.</u>Mounted and mounted so as to conduct heat to the outer surface of the light source mounting part via this board<u style="single">Be done</u>。 </p><p> In the present invention, the translucent cover is mainly provided to prevent other objects from coming into contact with the point light source forming the charging portion, and is flat even if it has a glove shape. It may be in the shape. When this cover is a glove, it does not prevent a reflective film from being provided on a part of the inner surface thereof, and the shape of the cover can be arbitrary in order to diffuse or collect the light emitted by the point light source, for example. it can. Further, as the translucent cover, it is also possible to use a lens for condensing or diffusing the light emitted by the point light source.</p><p> In the present invention, the lighting circuit is housed in the recess, but a part of the lighting circuit may be housed inside the mouthpiece. In the present invention, a synthetic resin such as PP (polypropylene) or PBT (polybutylene terephthalate) can be preferably used as the insulating member. In the present invention, the insulating member can also be formed of an insulating layer coated on the inner surface of the recess.</p><p> In the invention of claim 1, the heat of the point-shaped light source conducted to the light source mounting portion of the metal outer member can be conducted to the peripheral portion of the outer member and discharged to the outside from this peripheral portion. In this case, since the light source mounting portion and the peripheral portion of the outer member are integrally molded and have no joint portion, heat conduction from the light source mounting portion to the peripheral portion is good. Therefore, the cooling performance for the point light source by the heat from the outer member is excellent. Further, since the outer member is provided with a recess and the lighting circuit is housed therein, it is not necessary to secure a space for arranging the lighting circuit so as to be arranged in the axial direction with respect to the outer member. As a result, the axial length of the bulb-type lamp can be shortened. Further, a metal outer member and a lighting circuit housed in the recess thereof are provided between the two.<u style="single">It is housed in an insulating member having an opening on the base side and a closed wall part on the light source mounting part side with an electric wire through hole.</u>In addition to being electrically insulated, this insulating member can suppress heat transfer from the outer member forming the heat dissipation path of the point light source to the lighting circuit.</p><p> Further, in the invention of claim 2, the light source mounting portion is formed by the back wall of the recess, and the insulating member is separated from the back wall to provide a gap between the back wall and the insulating member.</p><p> In the invention of claim 2, the insulating member is not in contact with the light source mounting portion to which the point-shaped light source is mounted, and the heat transferred from the point-shaped light source to the light source mounting portion is conducted to the insulating member. Can be prevented by. Therefore, the thermal protection performance of the lighting circuit arranged in the outer member forming the heat dissipation path of the point light source can be improved.</p><p>Also,<u style="single">In the invention according to claim 1 or 2,</u>The insulating member opens into the mouthpiece and has a closing wall portion facing the opening to form a cup shape, and both sides of the circuit board face each other on the inner peripheral surface of the insulating member to form the lighting circuit. Placement<u style="single">Can be configured to.</u></p><p><u style="single">in this case,</u>Since the circuit board of the lighting circuit does not form a space between this and the closed wall portion of the cup-shaped insulating member in which heat is likely to be trapped, the heat of the light source mounting portion is likely to decrease, and the temperature of the point-shaped light source can be lowered. preferable. Further, in assembly, when the lighting circuit is inserted into the cup-shaped insulating member, the peripheral surface of the cup-shaped insulating member is less likely to get in the way and can be easily inserted, and the tip of the circuit board in the insertion direction closes the insulating member. Since the insertion depth is restricted by hitting the wall portion, the workability of assembling the lighting circuit in the cup-shaped insulating member can be improved.</p>

<p> According to the invention of claim 1, since the heat conduction from the light source mounting portion to the peripheral portion of the metal outer member is good and the cooling performance for the point light source is excellent, the temperature rise of the point light source is effective. Can be suppressed. Furthermore, it is possible to realize miniaturization by shortening the axial length of the light bulb type lamp, and it is possible to electrically insulate the lighting circuit inside the outer member forming the heat dissipation path of the point light source, and also thermally. Since it can be protected, it is possible to provide a bulb-type lamp capable of suppressing a decrease in the operation reliability and life of the lighting circuit.</p><p> According to the second aspect of the present invention, it is possible to provide a light bulb type lamp capable of improving the thermal protection performance of a lighting circuit arranged in an outer member forming a heat dissipation path of a point light source.</p>

The first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

Reference numeral 1 in FIGS. 1 and 2 indicates a bulb-type lamp (hereinafter abbreviated as a lamp). The lamp 1 includes a metal outer member 2, a point light source 11, a translucent cover 18, a lighting circuit 21, an insulating member 26, and a base 31.

The outer member 2 is made of, for example, an integrally molded product of aluminum. As shown in FIGS. 2 and 3, the outer member 2 is composed of a peripheral portion 3 and a light source mounting portion 4 integrated with the peripheral portion 3, and a recess 5 is formed inside the peripheral portion 3. The light source mounting portion 4 is formed by a back wall in which one end in the axial direction of the peripheral portion 3 is closed, and the recess 5 is opened at the other end in the axial direction of the peripheral portion 3.

The outer peripheral surface 3a (see FIG. 2) of the peripheral portion 3 functions as a heat radiating surface, and is a conical tapered surface whose diameter gradually decreases from the light source mounting portion 4 toward the opening edge portion 2a of the recess 5. It is formed. An annular locking groove 2b is provided on the inner peripheral surface of the opening edge 2a. A groove 2c is formed in a portion where the peripheral portion 3 and the light source mounting portion 4 are integrally continuous.

The groove 2c is provided in an annular shape around the light source mounting portion 4, for example, and is open to the outer surface of the peripheral portion of the light source mounting portion 4. By providing the groove 2c, the surface area (heat dissipation area) of the outer member 2 is increased as compared with the configuration without the groove 2c. In the outer member 2 whose heat radiation volume is limited due to the external shape required for the lamp 1, the heat radiation amount from the outer member 2 is increased by increasing the heat radiation area by the groove 2c. Therefore, it is preferable in suppressing the temperature rise of the light source mounting portion 4 and, by extension, the temperature rise of the point-shaped light source 11. This annular groove 2c also serves as a cover mounting groove as a preferable example.

As shown in FIGS. 2 and 4, a screw hole 4a is formed in the central portion of the light source mounting portion 4. As shown in FIG. 4, a pair of through holes 4b are formed in the light source mounting portion 4 with screw holes 4a in between. One end of the screw hole 4a and the through hole 4b is opened to the flat outer surface 4c of the light source mounting portion 4, and the other end of the screw hole 4a and the through hole 4b is opened to the inner surface of the light source mounting portion 4 parallel to the outer surface 4c. Has been done.

An LED is used for the chip-shaped light emitting element forming the point light source 11. A plurality of, for example, four (only two are shown) are mounted on the flat plate-shaped light source substrate 12, and the light source is mounted by fixing the light source substrate 12 to the outer surface 4c of the light source mounting portion 4. It is attached to part 4 so as to conduct heat.

Specifically, as shown in FIG. 4, the light source substrate 12 is provided with a pattern layer 12b made of a metal foil such as copper and an insulating resist layer 12c covering the pattern layer 12b on one surface of the insulating plate 12a. On the other surface of 12a, a heat diffusion layer 12d made of a metal foil such as copper and an insulating resist layer 12e covering the heat diffusion layer 12d are provided. The heat diffusion layer 12d is thicker than the pattern layer 12b and is formed corresponding to each point light source. A point light source 11 is connected to the pattern layer 12b of the light source substrate 12 and mounted on a surface. As the light source substrate 12, a metal substrate having excellent thermal conductivity having the above-mentioned layers provided on both sides thereof can be used, but from the viewpoint of cost, both sides of a resin substrate such as an epoxy resin mixed with glass powder can be used. It is preferable to use the one provided with each of the above-mentioned layers.

The light source substrate 12 is superposed on the outer surface 4c so that the heat diffusion layer 12d is on the back side, in other words, the heat diffusion layer 12d faces the outer surface 4c of the light source mounting portion 4. In this state, the light source substrate 12 is closely fixed to the outer surface 4c of the light source mounting portion 4 by screwing the screw 13 into the light source mounting portion 4 through the central portion of the light source substrate 12 and screwing the screw 13 into the screw hole 4a. As a result, the heat generated by the point light source 11 is transferred to the heat diffusion layer 12d having good thermal conductivity through the insulating plate 12a, diffused by the heat diffusion layer 12d, and then attached to the light source through the insulating resist layer 12e. It can be conducted directly to part 4.

In order to reduce the thermal resistance in the heat conduction path from the light source substrate 12 to the light source mounting portion 4, a heat transfer element such as silicon or grease is filled between the light source substrate 12 and the light source mounting portion 4. A heat transfer layer having good thermal conductivity may be provided.

The translucent cover 18 is made of, for example, a hemispherical glove made of synthetic resin or the like. The cover 18 is attached to the outer shell member 2 by fitting the opening edge portion 18a into the groove 2c of the outer shell member 2. Therefore, the cover 18 covers the light source mounting portion 4, and the point light source 11 faces the inner surface of the cover 18.

As shown in FIG. 2, the lighting circuit 21 for lighting the point light source 11 is unitized by attaching various circuit components 23 to the circuit board 22. The circuit board 22 has a circular shape, and the circuit component 23 includes a capacitor (not shown). Most of the circuit components 23 are mounted on one side of the circuit board 22 with their lead terminals penetrating the circuit board 22, and the lead terminals have a circuit pattern (not shown) provided on the other side of the circuit board 22. It is soldered.

The lighting circuit 21 is housed in the recess 5. The lighting circuit 21 has two insulated coated electric wires 24 (see FIG. 4) for electrically connecting to the point light source 11 and an insulated coated electric wire (not shown) for connecting to the base 31 described later. are doing. The insulating coated electric wire 24 is connected to the pattern layer 12b of the light source substrate 12 by soldering through the through hole 4b. Therefore, these insulating coated electric wires 24 support the lighting circuit 21 in the recess 5 in a suspended state in the direction of the lamp 1 shown in FIG.

The insulating member 26 is a molded product of a synthetic resin such as polybutylene terephthalate. The insulating member 26 has a cylindrical portion 26b that opens toward a base 31 to be described later and has a larger diameter toward the opening side, and a closed wall portion 26a that is continuous with one end of the cylindrical portion 26b and faces the opening. It has a cup shape. As shown in FIG. 2, the axial length A of the insulating member 26 is the length B along the axial direction of the outer member 2 from the inner surface of the light source mounting portion 4 (the inner wall surface of the recess 5) to the locking groove 2b. Shorter.

The insulating member 26 is provided so that its outer peripheral surface is in contact with the inner peripheral surface of the recess 5 and the outer surface of the closed wall portion 26a is in contact with the inner surface of the light source mounting portion 4. The lighting circuit 21 is housed inside the insulating member 26. In this case, the lighting circuit 21 faces the closed wall portion 26a with the surface of the circuit board 22 on which the lead terminal protrudes, and the surface on which the circuit component 23 is mounted faces the opening of the insulating member 26 in a horizontal position. It is housed in the insulating member 26. Therefore, the insulating member 26 is provided between the inner surface of the recess 5 and the lighting circuit 21 by partitioning the inner surface. As shown in FIG. 4, a pair of electric wire passage holes 26c for passing the insulating coated electric wire 24 are formed in the closed wall portion 26a of the insulating member 26.

The base 31 arranged on the opening edge 2a side of the outer member 2 for supplying power to the lighting circuit 21 has a base element 32 and a connecting member 33 fixed to the base element 32. The base element 32, which is detachably attached to a lamp socket (not shown), has, for example, a spiral groove at its peripheral portion, and forms a portion that is detachably screwed into a lamp socket (not shown). The connecting member 33 is made of an insulating material such as a synthetic resin such as polybutylene terephthalate, and is connected to the opening edge portion 2a of the recess 5.

For this connection, an annular locking convex portion 33a (see FIG. 3) is formed on the outer periphery of the tip portion of the connecting member 33. By fitting and locking the locking convex portion 33a into the locking groove 2b of the opening edge portion 2a, the base 31 and the outer member 2 are connected as shown in FIGS. 1 and 2. The connecting member 33, which is responsible for this connection, is interposed between the metal portion of the base element 32 and the metal outer member 2, and is electrically and thermally insulated between the two. ..

In this connected state, the outer peripheral surface 3a of the peripheral portion 3 and the outer peripheral surface of the connecting member 33 are flush with each other. Further, the insertion depth of the tip end portion of the connecting member 33 into the recess 5 is regulated by the stepped portion 33b of the connecting member 33 hitting the end surface of the peripheral portion 3. In order to prevent the locking protrusion 33a from engaging with the locking groove 2b due to dimensional variation, the regulation prevents the locking protrusion 33a from hitting the opening edge of the insulating member 26. (See Figure 2).

Since the lamp 1 having the above configuration accommodates the lighting circuit 21 in the recess 5 provided in the outer member 2, it is not necessary to secure a space for arranging the lighting circuit 21 so as to be arranged in the axial direction with respect to the outer member 2. .. As a result, the axial length of the lamp 1 is shortened, and the lamp 1 can be made compact.

In the compactification of the lamp 1, the insulating member 26 is interposed between the outer member 2 and the lighting circuit 21, so that the outer member 2 responsible for heat dissipation is made of metal as described later, but the concave portion thereof. The lighting circuit 21 built in 5 can be electrically insulated from the outer member 2.

When the lamp 1 is lit, the point light source 11 generates heat. This heat is cooled as follows, in addition to cooling by convection in the cover 18.

That is, the heat of the point-shaped light source 11 is directly conducted to the light source mounting portion 4 of the metal outer member 2, and then conducted to the peripheral portion 3 of the outer member 2, and the outer peripheral surface of the peripheral portion 3 is conducted. It is emitted from 3a to the outside of lamp 1.

Since the peripheral portion 3 of the outer shell member 2 provided by the lamp 1 and the light source mounting portion 4 are integrally molded and have no joint portion, the thermal resistance of the outer shell member 2 forming the heat dissipation path is small. Therefore, the heat conduction from the light source mounting portion 4 that receives the heat of the point light source 11 to the peripheral portion 3 is good, and the cooling performance for the point light source 11 due to the above heat dissipation is excellent. Therefore, it is possible to suppress an abnormal rise in the temperature of the point light source 11, and to suppress a decrease in luminous efficiency and a decrease in life of the point light source 11.

Moreover, the heat of the point-shaped light source 11 is directly transferred to the light source mounting portion 4 over a wide area by passing through the heat diffusion layer 12d of the light source substrate 12 on which the point-shaped light source 11 is mounted. Good heat conduction to member 2. In this respect as well, the cooling performance for the point light source 11 can be improved.

Further, since the cup-shaped insulating member 26 that electrically insulates the lighting circuit 21 from the outer member 2 forming the heat dissipation path is made of an insulating material having a lower thermal conductivity than the outer member 2, this insulation is provided. The member 26 can suppress the heat transfer of the outer member 2 to the lighting circuit 21 built in the outer member 2. Since the lighting circuit 21 in the recess 5 can be thermally protected in this way, it is possible to suppress a decrease in the operation reliability and the life of the lighting circuit 21.

Further, the lighting circuit 21 is formed in a space partitioned by an outer shell member 2 whose one end is closed by the light source mounting portion 4 and a base 31 connected to the opening edge portion 2a so as to close the other end of the outer shell member 2. It is housed and the outside air of Lamp 1 does not circulate in this space. Therefore, dust in the air, which causes a tracking phenomenon, does not adhere to the lighting circuit 21.

A second embodiment of the present invention will be described with reference to FIGS. 5 and 6. Since the second embodiment is basically the same as that of the first embodiment, the same parts are designated by the same reference numerals as those of the first embodiment, and the description thereof will be omitted.

In the second embodiment, a stopper portion 5a formed of an annular step portion or the like is provided at the inner portion of the concave portion 5, and the inner diameter of the inner portion of the inner portion of the concave portion 5 is narrowed. This narrowed inner diameter is smaller than the diameter of the closed wall portion 26a, which forms the minimum outer diameter of the cup-shaped insulating member 26. The stopper portion 5a is not annular, and may be formed by a plurality of convex portions.

By providing the stopper portion 5a, even when the insulating member 26 is accommodated to the innermost part of the recess 5, the light source mounting portion 4 and the insulating member 26 that also serve as the inner wall of the recess 5 are closed as shown in FIG. The wall portion 26a is separated from each other, and a gap G is provided between them.

Since the insulating member 26 is not in contact with the light source mounting portion 4 to which the point-shaped light source 11 is mounted due to this gap G, the insulating member 26 is directly transmitted from the point-shaped light source 11 to the light source mounting portion 4 while the lamp 1 is lit. The gap G can prevent heat from being directly conducted from the light source mounting portion 4 to the insulating member 26. Therefore, the thermal protection performance for the lighting circuit 21 arranged in the outer member 2 forming the heat dissipation path of the point light source 11 can be further improved. Along with this, the operation reliability of the lighting circuit 21 can be ensured, and the life reduction of the lighting circuit 21 can be suppressed.

Further, in the lamp 1 of the second embodiment, the outer diameter of the peripheral portion 3 of the outer shell member 2 has a straight shape in which the outer diameter does not change except for the end portion on the base 31 side, and the outer shell member 2 has a cylindrical shape. It gives a visual form. Further, the glove forming the translucent cover 18 of the lamp 1 has a tapered reflector portion 18b whose diameter gradually increases from the opening edge portion 18a and a hemispherical light projecting integrally with the reflector portion 18b. It is formed from a portion 18c, and the reflector portion 18b has a reflective film 18d on its inner surface. By using such a cover 18, it is possible to project light while condensing the light diffused by the reflective film 18d through the light projecting unit 18c.

Except for the matters described above, it is the same as the first embodiment. Therefore, also in this second embodiment, the same operation as in the first embodiment can be obtained, the temperature rise of the point light source 11 can be effectively suppressed, and the operation of the lighting circuit 21 can be achieved while reducing the size in the axial direction. It is possible to provide a lamp 1 capable of suppressing a decrease in reliability and life.

A third embodiment of the present invention will be described with reference to FIGS. 7 to 12. Since the third embodiment is basically the same as that of the first embodiment, the same parts are designated by the same reference numerals as those of the first embodiment, and the description thereof will be omitted. The third embodiment is different from the first embodiment in that the arrangement of the lighting circuit 21 and its support structure are different from those of the first embodiment, and further, a short-circuit prevention structure between the outer member 2 and the insulating coated electric wire 24 is provided. ..

Reference numeral 23a in FIGS. 7 and 8 indicates a capacitor mounted on the circuit board 22. This capacitor 23a is attached to a portion 22b on one end side of the circuit board 22. Here, the one-end side portion 22b of the circuit board 22 refers to an edge portion located on the side opposite to the insertion direction when the circuit board 22 is inserted into the cup-shaped insulating member 26 as described later. Reference numeral 23c in FIG. 8 indicates another circuit component such as a chip component surface-mounted on the surface of the circuit board 22 from which the lead terminal of the circuit component 23 protrudes.

As shown in FIG. 8, the circuit board 22 has a quadrangular shape and has a length protruding from the opening of the insulating member 26. Further, the circuit board 22 is provided with a pair of left and right stopper receivers 22a. The stopper portion receiver 22a is formed, for example, by notches provided on both the left and right sides of the one end side portion 22b of the circuit board 22, but is not limited to this and may be provided so as to project from both side edges of the circuit board 22. Alternatively, the one end side portion 22b of the circuit board 22 itself can be used as the stopper portion receiver 22a.

As shown in FIG. 8, a pair of stopper portions 33c are integrally formed on the inner surface of the connecting member 33. These stopper portions 33c are arranged so as to come into contact with or be close to the stopper portion receiver 22a with a slight gap.

As shown in FIGS. 11A to 11C, the cylindrical portion 26b included in the cup-shaped insulating member 26 has a pair of overlay portions 27 that are thickened on the inner peripheral surface side thereof, and these overlay portions are formed. An engaging groove 28 is provided in the raised portion 27. The pair of engaging grooves 28 are provided substantially parallel to the central axis of the insulating member 26, one end thereof is opened to the opening of the insulating member 26, and the other end is closed by the closing wall portion 26a.

The lighting circuit 21 has the circuit board 22 in a vertical position with respect to the insulating member 26 housed in the recess 5, with the edge on the side opposite to the one end side portion 22b to which the capacitor 23a is attached at the head. Will be inserted. In this case, the circuit board 22 is inserted while its both side edges are fitted into the engaging grooves 28, respectively. In this insertion work, the cylindrical portion 26b of the cup-shaped insulating member 26 does not easily get in the way, so that the insertion is easy and the tip edge of the circuit board 22 in the insertion direction hits the closed wall portion 26a of the insulating member 26. Therefore, the insertion depth is regulated without requiring special consideration. Therefore, the workability of incorporating the lighting circuit 21 into the insulating member 26 is good.

As shown in FIG. 7, the circuit board 22 of the lighting circuit 21 inserted in this way stands up at a right angle to the closed wall portion 26a of the insulating member 26, and divides the inside of the cup-shaped insulating member 26 into two. There is. Therefore, the lighting circuit 21 is arranged so that both sides of the circuit board 22 face each other with the inner peripheral surface of the insulating member 26 (the inner surface of the cylindrical portion 26b).

As a result, most of the solder that fixes the lead terminals of each circuit component 23 to the circuit board 22 is kept away from the light source mounting portion 4 to which the point light source 11 is mounted and the closed wall portion 26a that is in contact with or is close to the point light source 11. The temperature rise of the solder can be suppressed. Moreover, in this arrangement state, the one end side portion 22b of the circuit board 22 to which the capacitor 23a is attached protrudes from the opening of the insulating member 26. That is, the capacitor 23a, which may shorten its life when overheated, is far away from the light source mounting portion 4 to which the point light source 11 is mounted. Therefore, the durability of the capacitor 23a can be improved.

Then, in the subsequent assembly, when the connecting member 33 of the base 31 is connected to the outer member 2, the stopper portion 33c of the connecting member 33 comes into contact with the stopper portion receiving 22a of the circuit board 22. The circuit board 22 is supported so as to be sandwiched between the portion 33c and the closed wall portion 26a. Further, as described above, the two spaces partitioned by the circuit board 22 are communicated with each other through the internal space of the base 31, and are connected to the internal space of the base 31 through the opening of the insulating member 26 of the lighting circuit 21. The protruding part is arranged. This state is shown in FIG.

As a result, the lighting circuit 21 is supported so as not to move in the direction in which the optical axis of the lamp 1 extends. Moreover, both side edges of the circuit board 22 are fitted into a pair of engaging grooves 28, and the lighting circuit 21 is supported so as not to move around the optical axis of the lamp 1. Therefore, the lighting circuit 21 can be incorporated in a stable state by the above assembly. When the side edge of the circuit board 22 and the engagement groove 28 are deeply fitted, the lighting circuit 21 is rotated around the optical axis even if only the side edge of the circuit board 22 is fitted in the engagement groove 28. Can be supported so that it does not move.

In this assembled state, the circuit board 22 is offset with respect to the central axis (optical axis) of the lamp 1 (see FIGS. 7 and 10) based on the positions of the pair of engaging grooves 28 (see FIGS. 7 and 10). The circuit component 23 mounted on one surface of the circuit board 22 has a higher mounting height than the surface-mounted circuit component 23c such as a chip component. Nevertheless, the circuit components 23 having a high mounting height are moved away from the inner peripheral surface of the peripheral portion 3 of the outer member 2 by the offset, and these circuit components 23 are radiated to the inside of the peripheral portion 3 by heat. Can be less affected. At the same time, a larger space is secured between the other surface of the circuit board 22 on which the lead terminal of the circuit component 23 is projected and the inner peripheral surface of the peripheral portion 3. As a result, the temperature of the soldered surface of the circuit board 22 can be prevented from rising abnormally.

In the third embodiment, the lighting circuit 21 is housed in the insulating member 26 so that the circuit board 22 has a vertical posture substantially parallel to the central axis (optical axis) of the lamp 1, and the lighting circuit 21 Both sides of the circuit board 22 are opposed to the inner peripheral surfaces of the cup-shaped insulating member 26, respectively. As a result, a space in which heat is likely to be trapped is not formed between the circuit board 22 housed in the insulating member 26 and the closed wall portion 26a of the insulating member 26. Therefore, the heat of the light source mounting portion 4 tends to decrease, which is preferable in lowering the temperature of the point light source 11. Further, since the circuit board 22 is arranged upright in the direction in which the optical axis extends as described above, the length of the circuit board 22 is not restricted by the diameter of the cup-shaped insulating member 26, and therefore the circuit board 22 is not restricted. Can be increased. Thereby, it is possible to mount more circuit components 23 required in the design of the electric circuit required for the lamp 1.

Next, a short-circuit prevention structure between the outer member 2 and the insulating coated electric wire 24 will be described.

As shown in FIG. 9, the pair of through holes 4b provided in the light source mounting portion 4 with the screw holes 4a in between are not straight holes, but are stepped so that the outer surface 4c side of the light source mounting portion 4 has a large diameter. It is formed of holes. Insulating cylinders 29 formed of an electrically insulating resin such as PBT (polybutylene terephthalate) are fitted into these through-holes 4b, respectively, and the entire inner surface of the through-holes 4b is covered by the insulating cylinders 29.

As shown in FIG. 12 and the like, the outer shape of the insulating cylinder 29 is the same as that of the through hole 4b, and has a through hole 29a in the central portion thereof. The inner surface side end of the light source mounting portion 4 of the through hole 29a is enlarged in diameter by a tapered chamfer (see FIG. 9) and communicated with the electric wire passage hole 26c of the insulating member 26. As a result, when the insulating coated electric wire 24 is passed through the through hole 29a, the insulating coated electric wire 24 is prevented from being caught in the insulating cylinder 29.

The insulated coated electric wire 24 connected to the circuit board 22 is soldered to the light source substrate 12 through the wire through hole 26c at the tip where the core wire (copper wire) 24a is exposed. In this case, even if the exposed core wire 24a is located inside the through hole 4b as illustrated in FIG. 9 due to the variation in the removal dimension of the insulating coating, the core wire 24a and the metal light source are attached. The insulation cylinder 29 can prevent the possibility of short-circuiting with the part 4.

The stepped insulating cylinder 29 is sandwiched between the light source substrate 12 and the step on the inner surface of the through hole 4b by screwing the light source substrate 12 to the light source mounting portion 4 after fitting the insulating cylinder 29 into the through hole 4b. Therefore, it is not necessary to bond the insulating cylinder 29 to the through hole 4b, and it is easy to assemble.

Further, the insulating coated electric wire 24 drawn from the circuit board 22 is soldered to a soldering land (not shown) of the light source substrate 12 through the electric wire through hole 12f (see FIG. 10) opened in the light source substrate 12. .. In this case, since the circuit board 22 is offset as described above, the electric wire through hole 12f can be opened just in the middle portion between the adjacent point light sources 11. As a result, the area of the heat diffusion layer 12d of the light source substrate 12 is less likely to be reduced by the electric wire through hole 12f, so that the heat transfer (heat dissipation) performance from the point light source 11 to the light source mounting portion 4 via the heat diffusion layer 12d. Is preferable in order to suppress the temperature rise of the point light source 11.

Except for the matters described above, it is the same as the first embodiment. Therefore, also in this third embodiment, the same operation as in the first embodiment can be obtained, the temperature rise of the point light source 11 can be effectively suppressed, and the operation of the lighting circuit 21 can be achieved while reducing the size in the axial direction. It is possible to provide a lamp 1 capable of suppressing a decrease in reliability and life. Further, the arrangement of the lighting circuit 21 and the short-circuit prevention structure described in the third embodiment can be applied to the second embodiment.

The present invention is not limited to each of the above embodiments. For example, if there are no restrictions on the size of the outer diameter of the lamp 1, the lighting circuit 21 can be arranged so that it fits over the inside of the recess 5 and the inside of the insulating connecting member 33 of the base 31. As a result, the axial length of the peripheral member 2 of the outer member 2 can be shortened in accordance with the fact that the axial length of the cup-shaped insulating member 26 can be shortened, so that the axial length of the lamp 1 can be further shortened. However, in this case, as the axial length of the peripheral portion 3 becomes shorter, the surface area of the outer peripheral surface (heat dissipation surface) 3a decreases, so that the outer diameter of the peripheral portion 3 is increased to compensate for this. do it.

<figref num="1">The perspective view which shows the light bulb type lamp which concerns on 1st Embodiment of this invention.</figref><figref num="2">FIG. 5 is a cross-sectional view showing the light bulb type lamp of FIG.</figref><figref num="3">FIG. 5 is a cross-sectional view showing the light bulb type lamp of FIG. 1 in an exploded manner.</figref><figref num="4">Sectional view shown along line F4-F4 in FIG.</figref><figref num="5">The perspective view which shows the light bulb type lamp which concerns on 2nd Embodiment of this invention.</figref><figref num="6">FIG. 5 is a cross-sectional view showing a light bulb type lamp of FIG.</figref><figref num="7">The cross-sectional view which shows the light bulb type lamp which concerns on 3rd Embodiment of this invention.</figref><figref num="8">Sectional view along the F8-F8 line in Fig. 7.</figref><figref num="9">FIG. 8 is an enlarged cross-sectional view showing the F9 part in FIG.</figref><figref num="10">Front view showing the bulb-shaped lamp of FIG. 7 with the cover removed.</figref><figref num="11">(A) is a top view showing an insulating member included in the light bulb type lamp according to the third embodiment. (B) is a cross-sectional view taken along the line F11B-F11B in FIG. 11 (A). (C) is a cross-sectional view taken along the line F11C-F11C in Fig. 11 (A).</figref><figref num="12">The perspective view which shows the insulation cylinder provided with the light bulb type lamp which concerns on 3rd Embodiment.</figref>

Code description

1 ... light bulb type lamp, 2 ... outer member, 2a ... opening edge of outer member, 2b ... locking groove, 3 ... peripheral part of outer member, 3a ... peripheral part Outer surface (heat dissipation surface), 4 ... light source mounting part of outer member, 4a ... screw hole, 4c ... outer surface of light source mounting part, 5 ... recess of outer member, 5a ... stopper Part, 11 ... Point light source,<u style="single">12 ... Light source board,</u>13 ... screws, 18 ... translucent covers, 21 ... lighting circuits, 22 ... circuit boards, 23 ... circuit parts, 26 ... insulation members, 26a ... closed walls , 26b ... Cylindrical part, 28 ... Engagement groove, 31 ... Mouthpiece, 32 ... Mouthpiece element, 33 ... Connecting member, 33a ... Locking convex part, G ... Void