GB2298036A

GB2298036A - A vehicular lamp provided with cooling means

Info

Publication number: GB2298036A
Application number: GB9602456A
Authority: GB
Inventors: Shinji Watanabe; Naomasa Ogura
Original assignee: Koito Manufacturing Co Ltd
Current assignee: Koito Manufacturing Co Ltd
Priority date: 1995-02-15
Filing date: 1996-02-07
Publication date: 1996-08-21
Anticipated expiration: 2016-02-07
Also published as: JP3247569B2; GB2298036B; GB9602456D0; JPH08222008A

Abstract

A vehicular lamp which includes a lamp body, a reflector and an inner lens both disposed in the lamp body, a light source located within a lamp chamber defined by the lamp body and the reflector, and a couple of air communication holes formed in the reflector at both upper and lower portions thereof sandwiching the light source.

Description

VEHICULAR LAMPS The present invention relates generally to a vehicular lamp having a reflector, an inner lens, a lamp chamber defined by the reflector and the inner lens, and a light source mounted within the lamp chamber. More particularly, the invention relates to a vehicular lamp in which an air communication hole is formed in the reflector so that heat generated by the light source discharges out of the lamp chamber.

There has been known a conventional vehicular lamp which includes a lamp body, a lens for covering an opening of the lamp body, a lamp chamber defined by the lamp body and the lens, a reflector disposed within the lamp chamber, and an inner lens disposed to cover an opening of the reflector.

Fig. 7 shows one example of the conventional lamp a.

The lamp a is constituted by a lamp body b formed of synthetic resin having an opening c directing frontward, i.e., the direction of illumination of the lamp. A lens d is mounted to the opening c, and a reflector f formed of synthetic resin is disposed within a lamp chamber e defined by the lamp body k and the lens d. The reflector f has an opening g directing frontward. An inner lens h for covering the opening g of the reflector f is provided with lens steps (not shown).

A light bulb i having a glass tube i is mounted within a lamp chamber m defined by the inner lens h and the reflector f through bulb insertion holes k and 1 formed in the lamp body b and the reflector f, respectively. The bulb insertion hole 1 formed in a rear end portion of the reflector f is closed by a flange n of the light bulb i, so that the lamp chamber m is a closed chamber.

With the conventional lamp a described above, air heated by the light bulb i moves up within the lamp chamber m as indicated by arrows shown in Fig. 7. The heated air may cause problems that the inner lens h collects moisture which deteriorates the light distribution pattern, and the reflector f is deformed by the heat gathering at the upper part of the lamp chamber m.

The present invention was made in view of the foregoing problems accompanying the conventional vehicular lamp. Accordingly, an object of the present invention is to provide a vehicular lamp capable of discharging heat generated by a light source out of a lamp chamber.

The above and other objects can be accomplished by a provision of a vehicular lamp which, according to the present invention, includes a lamp body, a reflector and an inner lens both disposed in the lamp body, a light source located within a lamp chamber defined by the lamp body and the reflector, and a pair of air communication holes formed in the reflector, preferably at both upper and lower portions thereof sandwiching the light source.

According to the present invention, since an air communication hole is formed in the reflector at both upper and lower portions thereof sandwiching the light source, an air flow passage is created between the lamp chamber defined by the reflector and the inner lens and the outside of the lamp chamber, so that the heat can be discharged out of the lamp chamber.

In the accompanying drawings: Fig. 1 is a front view of an automotive headlamp to which the present invention is applied; Fig. 2 is a sectional view of the automotive headlamp cut along a line II-II in Fig. 1; Fig. 3 is a sectional view of the automotive headlamp cut along a line III-III in Fig. 1; Fig. 4 is a sectional view of the automotive headlamp cut along a line IV-IV in Fig. 1; Fig. 5 is a partially enlarged rear view of a reflection section of a reflector for sub-beam according to the present invention; Fig. 6 is a sectional view of the automotive headlamp to which an arrangement of the present invention is applied; and, Fig. 7 is a sectional view showing a conventional vehicular lamp.

In the embodiment described below, the invention is applied to an automotive headlamp as one example.

As shown in the figures, a headlamp 1 is provided with a lamp body 2 having a front opening, a front lens 3 covering the front opening of the lamp body 2 and a lamp chamber 4 which is defined by the lamp body 2 and the front lens 3. The lamp body 2 formed of synthetic resin has a concave portion 2a which opens frontward as shown in Fig.

2. As best shown in Figs. 3 and 4, a lens mounting section 5 is formed on an opening periphery of the lamp body 2 for attaching the front lens 3. The lens mounting section 5 is formed with a lens mounting groove 5a which opens frontward.

The lamp body 2 comprises two sections 2A and 2B located adjacent to each other, and a reflection member for a main beam is disposed within a room 4a defined by the section 2A and the corresponding part of the front lens 3 whereas a different reflection member for a sub-beam is disposed within a room 4b defined by the section 2B and the corresponding part of the front lens 3 as shown in Fig. 2.

A cylindrical projection 7 is formed integrally with a rear wall 6 of the section 2A of the lamp body 2, which projects rearward, and a flange 8 protruding from an inner surface of the cylindrical projection 7 toward the center thereof defines an essentially circular large opening 9. On the other hand, a cylindrical projection 11 which projects rearward is formed integrally with a rear wall 10 of the section 2B of the lamp body 2, and a flange 12 protruding from an inner surface of the cylindrical projection 11 toward the center thereof defines an essentially circular large opening 13.

The front lens 3 is constituted by a front section 14 for covering the front opening of the concave portion 2a of the lamp body 2 and a peripheral wall section 15 projecting rearward from a peripheral edge of the front section 14.

The front section 14 and the peripheral wall section 15 are integrally formed of synthetic resin. A rear end 18 of the peripheral wall section 15 engages with the lens mounting groove 5a of the lamp body 2 through a seal agent 16 and, under this condition, the rear end 18 of the peripheral wall section 15 is fastened to the lens mounting section 5 by clips of a plate-spring type as shown in Fig. 1, so that the front lens 3 is secured to the lamp body 2.

A reflector 19 formed of synthetic resin is provided integrally with a reflection section 20 for main beam and a reflection section 21 for sub-beam. Though not shown in the figures, the reflector 19 is supported on the lamp body 2 in such a manner that the reflector 19 is tiltable in vertical and horizontal directions within the lamp chamber 4 by means of an aiming mechanism (not shown).

The reflection section 20 includes an effective reflection part 20a on which a predetermined reflective surface is formed and a side surface part 20b extending frontward from a peripheral edge of the effective reflection part 20a. As shown in Fig. 2, a bulb mounting hole 22 is formed in the effective reflection part 20a at substantially the center thereof.

The reflection section 21 includes, on the other hand, an effective reflection part 21a on which a predetermined reflective surface is formed and a side surface part 21b extending frontward from a peripheral edge of the effective reflection part 22a. Steps 24, 24 are formed on a front end part 23a of an upper surface 23 of the side surface part 21b as partly shown in Fig. 4. Further, as shown in Fig. 3, an engagement hole 25a is formed in a bottom part 25 of the side surface part 21b. A bulb mounting hole 26 is formed in the effective reflection part 21a at substantially the center thereof. As shown in Fig. 5, the bulb mounting hole 26 extends in the vertical direction like a character I, and a notch 26a extending sideward continuously from the I-shaped hole, which performs to define a right position of the light bulb which is mounted in the bulb mounting hole 26.

An inner lens 27 for covering the opening of the reflection section 21 is formed of a glass material or synthetic resin. As shown in Fig. 3, the inner lens 27 is formed with a protrusion 27a projecting downward which engages with the engagement hole 25a of the side surface part 21b of the reflection section 21. As shown in Fig. 4, clips 28, 28... of a plate spring type (merely one clip is shown in the figure) fastens an upper part of the inner lens 27 and the steps 24 ? 24... of the upper surface 23 of the reflection section 21 to thereby sandwich the inner lens 27 and a front part of the reflection section 21, so that the inner lens 27 is coupled to the reflection section 21 and, hence, a lamp chamber 29 is defined.

As shown in Fig. 5, a pair of arcuate slot-like air communication holes 30, 31 are formed in the effective reflection part 2la. The upper air communication hole 30 and the lower air communication hole 31, which sandwich the bulb mounting hole 26, are provided to form an air flow passage for discharging air heated by the light bulb out of the lamp chamber 29. Therefore, the upper air communication hole 30 performs as a heat discharging hole whereas the lower air communication hole 31 functions as an intake.

After air flowing into the lamp chamber through the lower air communication hole 31 is heated by the light bulb, the heated air discharges out of the lamp chamber 29 through the upper air communication hole 30. In a case where the effective reflection part 21a is shaped to be completely or essentially circularly symmetrical with respect to an optical axis, the air communication holes 30 and 31 should be positioned on a circle a center point of which is the optical axis so that distortion in the vicinity of the air communication holes 30, 31 can be minimized during the molding process of the reflector 19 A light bulb 32 for the main beam shown in Fig. 2 comprises a glass tube 32a which is inserted through the opening 9 of the lamp body 2 and the bulb mounting hole 22 and mounted on the reflection section 20. A metal piece 33 of the light bulb 32 is provided with a flange 34.When the light bulb 32 is mounted on the reflection section 20, the glass tube 32a and a front half of the metal piece 33 pass through the bulb mounting hole 22 while positioning the light bulb 32 with respect to the bulb mounting hole 22, and then the flange 34 comes into abutment against a rear end surface of the reflection section 20. Thereafter, a set spring 35 resiliently engages with the rear end part of the metal piece 33 to thereby urge the flange 34 against the rear end surface of the reflection section 20, so that, under this condition, the light bulb 32 is mounted to the reflection section 20. The set spring 35 has one end secured by a screw to the rear end surface of the reflection section 20 and the other end engaging with an engagement claw 36 projecting from the rear end surface of the reflection section 20.Under a condition where the light bulb 32 is mounted to the reflection section 20, the metal piece 33 protrudes rearward from the bulb mounting hole 22. The metal piece 33 is formed at a rear end portion with contact pieces 37, 37.

On the other hand, a light bulb 38 for the sub-beam comprises a glass tube 38a which is passed through the opening 13 of the lamp body 2 and the bulb mounting hole 26 of the reflection section 21 and disposed within the lamp chamber 29. A metal piece 39 of the light bulb 38 is formed with a flange 40. When the light bulb 38 is mounted to the reflection section 21, the glass tube 38a and a front half part of the metal piece 39 are passed through the bulb mounting hole 26 while positioning the bulb by engaging a protrusion (not shown) formed on the flange 40 with a notch 26a of the bulb mounting hole 26, and then the flange 40 comes into abutment against a rear end surface of the reflection section 21.Thereafter, a set spring 41 resiliently engages with the rear end part of the metal piece 39 to thereby urge the flange 40 against the rear end surface of the reflection section 21, so that, under this condition, the light bulb 38 is mounted to the reflection section 21. The set spring 41 has one end secured by a screw to the rear end surface of the reflection section 21 and the other end engaging with an engagement claw 42 projecting from the rear end surface of the reflection section 21. Under a condition where the light bulb 38 is mounted to the reflection section 21, the metal piece 39 protrudes rearward from the bulb mounting hole 26. The metal piece 39 is formed at a rear end portion with contact piece 43.

Adaptor members 44 and 44' are coupled to the rear end part of the reflection sections 21 and 20, respectively.

Because the adaptor members 44 and 44' have the same configuration as each other, the following description refers merely to the adaptor member 44 at the light bulb 38 side for the sub-beam whereas the description of the adaptor member 44' will be omitted here, while designating the same reference numerals as those of the adaptor member 44.

As best shown in Fig. 3, the adaptor member 44 is provided with connector sections 45, 45 which engage separately with the contact piece 43 of the light bulb 38 and the rear end part of the metal piece 39a, respectively.

Contact pieces 45a, 45a partly constituting the respective connector sections 45, 45 project rearward from the rear end surface of the adaptor member 44. The adaptor member 44 is coupled to the rear end part of the reflection section 21 by a not shown structure so that it covers the rear portion of the metal piece 39.

Cap members 46 and 46' holding the adaptor members 44 and 44' are coupled to the rear end parts of a section 2A, 2B, respectively, of the lamp body 2. Because the cap members 46 and 46' have the same configuration as each other, the following description refers merely to the cap member 46 at the light bulb 38 side for the sub-beam whereas the description of the cap member 46' will be omitted here, while designating the same reference numerals as those of the cap member 46.

As shown in Fig. 3, the cap member 46 is constituted by a socket cover 47 formed of rubber material and a ring-like shaped lock ring 48 formed of synthetic resin.

The socket cover 47 is composed of a holding part 47a for holding the adapter member 44, a body part 47b coupled to the lock ring 48 and a thin bellows part provided between the holding part 47a and the body part 47b. When the cap member 46 is coupled to the lamp body 2, first, the body part 47b is coupled to the lock ring 48, next, a front end part of the lock ring 48 engages with the opening 13 of the lamp body 2 while passing engagement parts 48a, 48a...

formed on the front end part of the lock ring 48 through notches (not shown) formed continuously on the opening 13 of the lamp body 2 and, thereafter, the lock ring 48 rotates. Thus, the front end part of the lock ring 48 fits in the opening 13 of the lamp body 13 and the cap member 46 is coupled to the rear end part of the section 2B of the lamp body 2.

As described above, since the headlamp 1 is provided with the air communication holes 30 and 31 formed in the reflection section 21, which holes allow the lamp chamber 29 to communicate with the outside thereof, air convection is created within the lamp chamber 29 when the light bulb 38 is turned on and, therefore, the air flows in and out of the room 4b of the headlamp 1 through the upper and lower air communication holes 30 and 31. That is, the upper air communication hole 30 performs as a heat discharging hole whereas the lower air communication hole 31 functions as an intake. After air flowing into the lamp chamber through the lower air communication hole 31 is heated by the light bulb, the heated air discharges out of the lamp chamber 29 through the upper air communication hole 30.

Though the air communication holes 30 and 31 are formed in the effective reflection part 21a in the embodiment described above, the present invention is not limited thereto or thereby. For example, in case of a headlamp 1A as shown in Fig. 6, a pair of air communication slot-like holes 30A and 31A may be formed in a top surface 23 and a bottom surface 25, respectively, of the side surface part 21b of the reflection section 21. The primary purpose is to provide a pair of air communication holes in the reflection section 21 in order to discharge heat generated by a light source out of the lamp chamber 29.

According to the present invention, since the air communication hole is formed in the reflector at both upper and lower portions thereof, sandwiching the light source, an air flow passage is created between the lamp chamber defined by the reflector and the inner lens and the outside of the lamp chamber, so that the heat can be discharged out of the lamp chamber.

Claims

1. A vehicular lamp comprising a lamp body having a front opening; a front lens coupled to the front opening of the lamp body; a lamp chamber defined by the lamp body and the front lens; a reflector disposed within the lamp chamber; a light source mounted to the reflector and disposed within the lamp chamber; and a pair of air communication holes formed in the reflector.

2. A lamp according to claim 1, wherein the air communication holes are formed opposite to each other with respect to the light source.

3. A lamp according to Claim 2, wherein the air communication holes are formed respectively at upper and lower portions of the reflector sandwiching the light source between them.

4. A lamp according to any one of the preceding claims, wherein the air communication holes are formed in an effective reflection part of the reflector.

5. A lamp according to any one of the preceding claims, wherein the air communication holes are formed in a top surface and a bottom surface of a side surface part of the reflector.

6. A lamp according to any one of the preceding claims, wherein the air communication holes are arcuately shaped.

7. A lamp according to claim 6, wherein the air communication holes are positioned on a circle a center point of which is an optical axis of the lamp.

8. An automotive headlamp comprising a lamp body having a first section for a main beam and a second section for a sub-beam, the lamp body having a front opening; a front lens coupled to the front opening of the lamp body; a first lamp chamber defined by the lamp body and the front lens; a first reflector disposed within the first section of the lamp body; a second reflector disposed within the second section of the lamp body; a first light source mounted to the first reflector and disposed within the first lamp chamber; a second light source mounted to the second reflector and disposed within the first lamp chamber; and a pair of air communication holes formed in at least one of the first and second reflectors.

9. A headlamp according to Claim 8, wherein the air communication holes are formed opposite to each other with respect to the light source.

10. A headlamp according to Claim 9, wherein the air communication holes are formed respectively at upper and lower portions of the reflector sandwiching the light source between them.

11. A headlamp according to any one of claims 8 to 10, wherein the air communication holes are formed in an effective reflection part of the reflector.

12. A headlamp according to any one of claims 8 to 11, wherein the air communication holes are formed in a top surface and a bottom surface of a side surface part of the reflector.

13. A headlamp according to any one of claims 8 to 12, wherein the air communication holes are arcuately shaped.

14. A headlamp according to claim 13, wherein the air communication holes are positioned on a circle a center point of which is an optical axis of the lamp.

15. A headlamp according to any one of claims 8 to 14, further comprising an inner lens coupled to an opening of the reflector in which the air communication holes are formed.

16. A headlamp according to claim 15, wherein the inner lens is formed of a glass material.

17. A headlamp according to claim 15, wherein the inner lens is formed of synthetic resin.

18. A headlamp, substantially as described with reference to Figures 1 to 6 of the accompanying drawings.