JPH07262808A - Method for connecting lens to housing of lighting fixture for vehicle - Google Patents

Abstract

PURPOSE:To easily provide a lighting fixture for vehicle connected airtightly at a high dimensional accuracy, by fitting and pressing the peripheral edge of a resin lens to the circular opening end of a resin lamp housing, and heating them by a high-frequency wave, so as to fuse and fix them. CONSTITUTION:The circular opening end 26a of a lens 23 made of a resin is fitted to the circular opening end 22a of a lamp housing 22 made of a resin, and pressed through work holding molds 41 and 42. At the same time, the fitting parts are heated by a high-frequency heating means 50. It is preferable to form a space 27 to the fitting parts by an inner circular thin wall 22b and a circular connecting projection 26b respectively through a taper form inner surface 26d. The heating means 50 is preferable to be made by fixing a circular permeable heating member 52 and a high-frequency coil 53 to the work holding mold 41 through a bracket 51. Consequently, the lens 23 and the housing 22 can be connected airtightly without generating any burr, unevenness of form, and the like, by fusing and fixing the fitting parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention hermetically joins a lens and a lamp housing by melting and fixing a mating portion of a resin lamp housing and a resin lens which are open to one side by heating means. The present invention relates to a method for joining a lens and a housing of a vehicle lamp as described above.

[0002]

2. Description of the Related Art As a vehicular lamp, for example, as shown in FIG. 6, an open end of a lamp housing 1 which is open to one side is closed by a lens 2 to connect the lamp housing 1 and the lens 2. There is a configuration in which a lamp chamber 3 is formed therebetween, a lamp housing 1 holds a bulb socket 4, and a bulb 5 held by the bulb socket 4 is disposed in the lamp chamber 3.

In this type of vehicular lamp, the lamp housing 1 and the lens 2 are hermetically bonded so that rainwater or the like does not enter the lamp chamber 3 from the joint between the lamp housing 1 and the lens 2. On the other hand, in most cases, the lamp housing 1 and the lens 2 are made of synthetic resin in order to reduce the weight of the vehicular lamp and improve the workability.

Further, conventionally, the above-mentioned lamp housing 1 has been used.
As a method for hermetically bonding the lens 2 and the lens 2 to each other, a fusion bonding method by contact heating using a heating plate 6 (hot plate) and a work pressurizing device 7 as shown in FIG. 7 is considered.

The work pressing device 7 includes work holding dies 8 and 9 which can approach and separate from each other, and work holding dies 8 and 9 for restricting the minimum distance between the work holding dies 8 and 9.
In addition to having stoppers (not shown) provided at positions not shown in the figure, solenoids (not shown) for driving the first work holding dies 8 and 9 relatively toward and away from each other are provided.

In the fusion bonding method using the heating plate 6 and the work pressurizing device 7 as described above, first, as shown in FIG. 7A, the lamp housing 1 is held in the work holding recess 8a of the work holding die 8. Then, the lens 2 is held in the work holding recess 9a of the work holding die 9, and the work holding dies 8 and 9 are widely opened to separate the lamp housing 1 from the lens 2.

Next, after moving the heating plate 6 heated to 230 ° C. to 380 ° C. between the work holding molds 8 and 9 and between the lamp housing 1 and the lens 2 as shown in FIG. 7B, By operating a solenoid (not shown), the work holding molds 8 and 9 are moved to the heating plate 6 side, and the open end 1a (joint part) of the lamp housing 1 and the open end 2a (joint part) of the lens 2 are illustrated. As shown in 7 (c), the open end portions 1a and 2a are slightly melted by being brought into pressure contact with the heating plate 6.

Thereafter, the work holding dies 8 and 9 are largely separated from each other by a solenoid (not shown) as shown in FIG. 7 (d) so that the lamp housing 1 and the lens 2 are heated.
Then, the heating plate 6 is pulled out from between the work holding molds 8 and 9 and between the lamp housing 1 and the lens 2 as shown in FIG. 7 (e).

Then, as shown in FIG. 7 (f), the work holding dies 8 and 9 are brought close to each other by a solenoid (not shown), and the open end 1a of the lamp housing 1 and the open end 2a of the lens 2 are pressed against each other. Then, the lamp housing 1 and the lens 2 are joined by fixing the melted portions of the open ends 1a and 2a to each other.

Thereafter, when the work holding molds 8 and 9 are opened by a solenoid (not shown) as shown in FIG. 7 (g), the lens 2 is joined to the lamp housing 1 and remains on the lamp housing 1 side, and the work holding molds 8 and 9 are left. Is further opened to take out the lamp housing 1 and the lens 2 joined to each other from the work holding mold 8.

[0011]

By the way, in such a fusion bonding method, the open ends 1a and 2a of the lamp housing 1 and the lens 2 are brought into direct contact with the heating plate 6 to be heated and fused. 6) to (f) are required, which is troublesome.

Further, since the open ends 1a and 2a of the lamp housing 1 and the lens 2 are brought into direct contact with the heating plate 6 to be heated and melted, the molten resin at the open ends 1a and 2a can be easily released. Teflon coating or the like is required on the surface of the heating plate 6, and the heating plate 6 is provided in addition to the solenoid for driving the work holding molds 8 and 9.
There is also a problem that the equipment cost is high because a drive device for moving and driving is required.

Further, since the open ends 1a and 2a of the lamp housing 1 and the lens 2 are brought into direct contact with the heating plate 6 to be heated and melted, the molten resin may remain on the surface of the heating plate 6 due to carbonization. Moreover, when the carbonized resin (carbonized resin) is held between the open ends 1a and 2a at the time of joining the lamp housing 1 and the lens 2 which are the next products, the carbonized resin is passed through the carbonized resin. There has been a problem that rainwater may enter the lamp chamber 3 and cause water leakage.

Furthermore, in the above-described fusion bonding method, the melting margin of the open ends 1a, 2a by the heating plate 6 is different for each heat fusion bonding of the product (the lamp housing 1 and the lens 2). The appearance of the joint portion 2a was different for each product, which was not preferable.

As shown in an enlarged view in FIG. 7 (h), burrs 10 and 10 'are also generated on the inner and outer surfaces of the open ends 1a and 2a, and the burrs 10 are lens prisms such as fisheye lenses. This is not preferable in terms of the appearance of the product because it produces the effect and the internal valve and the like are partially enlarged at the burr 10 and visually recognized from the outside.

Therefore, the first object of the present invention is to reduce the number of steps for melting and joining the lamp housing and the lens by allowing the portion to be joined to be heated and fused without directly contacting the heating means. Thus, it is an object of the present invention to provide a method of joining a lens and a housing of a vehicular lamp that does not require any trouble.

Further, a second object of the present invention is to make it possible to heat and melt the joined portion without directly contacting the portion to be joined with the heating means, so that a conventional method for fusion joining the lamp housing and the lens is achieved. It is an object of the present invention to provide a method of joining a lens and a housing of a vehicular lamp that can simplify the equipment and reduce the equipment cost by omitting the heating plate.

Further, a third object of the present invention is to omit the conventional heating plate for melting and joining the lamp housing and the lens, and to heat and melt the joined portion without directly contacting it with the heating means. Accordingly, it is an object of the present invention to provide a method for joining a lens and a housing of a vehicular lamp that does not cause water leakage due to a carbonized resin as in the related art.

Further, a fourth object of the present invention is to prevent the melting margin of the jointed portion from being different (varied) each time the product is heated and melted by the heating means, thereby impairing the appearance of the jointed portion. It is an object of the present invention to provide a method of joining a lens of a vehicle lighting device and a housing that can prevent the occurrence of the above.

A fifth object of the present invention is to provide a method of joining a lens and a housing of a vehicle lamp, in which burrs due to melting of the joined parts do not occur on the inner surfaces of the joined parts.

Further, a sixth object of the present invention is to provide a method for joining a lens of a vehicle lamp and a housing in which a large burr is hardly generated on the outer surface side when the joined parts are melt-joined.

[0022]

In order to achieve the first to fourth objects, the invention according to claim 1 provides a lamp housing made of resin and a lens made of resin which are open to one side. While pressing the peripheral portion of the lamp housing in conformity with the annular open end of the lamp housing, by melting and fixing the mating portion of the lamp housing and the lens,
In a method for joining a lens and a housing of a vehicle lamp in which the lens and the lamp housing are hermetically joined, the joining portion is heated by a high-frequency heating means arranged along the joining portion, and the joining portion is heated. A method of joining a lens and a housing of a vehicular lamp in which the lens and the lamp housing are airtightly joined by melting and fixing the portion.

Further, in order to achieve the fifth object, the invention of claim 2 is such that the lens integrally includes an annular mounting leg extending along a peripheral edge, and the annular open end of the mounting leg and the lamp. By providing an inner annular thin portion on one inner peripheral side of the annular open end of the housing, an outer annular step joint surface is formed on the outer peripheral side of the one annular open end, and the inner annular thin wall is formed. A thin-walled annular joint projection that fits on the outer peripheral side of the portion and whose tip engages with the outer annular step joint surface is integrally formed on the other of the annular open end portions, and the annular joint protrusion is A method of joining a lens of a vehicle lamp and a housing, which is melted and fixed by the high-frequency heating means while being pressed against the outer annular step joint surface, is characterized.

Further, in order to achieve the sixth object, in the invention of claim 3, the annular joint protrusion has a tapered inner surface whose diameter increases toward the tip, and the annular joint protrusion is The method for joining a lens and a housing is such that the molten resin is moved to the inner annular thin portion side when being melted by the high-frequency heating means while being pressed by the outer annular step joint surface. To do.

[0025]

According to the invention of claim 1, the resin lamp housing and the resin lens which are open to one side are provided, and the peripheral edge of the lens is aligned with the annular open end of the lamp housing. The lens and the lamp housing are airtightly joined by melting and fixing the mating portion with high frequency heating means along the mating portion of the lamp housing and the lens while pressing.

According to the second aspect of the present invention, the annular joint protrusion provided on one side of the lamp housing and the lens is fitted to the outer peripheral side of the inner annular thin portion provided on the other side to form the outer annular step. While being pressed against the bonding surface, the high-frequency heating means melts and fixes it. At this time, the molten resin in the annular joint projection is prevented from moving to the inner surface side of the mating portion of the lamp housing and the lens by the action of the inner annular thin portion, and the burr is prevented from being generated on the inner surface side. .

Furthermore, in the invention of claim 3, a space is formed between the tapered inner surface of the annular joint projection provided on one side of the lamp housing and the lens and the inner thin annular portion provided on the other side. . As a result, when the annular joining protrusion is melted by the high-frequency heating means while being pressed against the outer annular step joining surface, the molten resin is moved toward the inner annular thin portion side, that is, the space side by the action of the tapered inner surface. After being moved, it is hardly moved to the outer surface side of the fitting portion of the lamp housing and the lens.

[0028]

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

In FIG. 2, 20 is a vehicular lamp (product), 21 is a bulb case of the vehicular lamp 20, and 21a is a lamp chamber in the bulb case 21.

This lamp case 21 has a resin lamp housing 22 which is open at one side, and a lamp housing 2.
It has a lens 23 made of resin fixed to 2. The vehicular lamp 20 also has a bulb socket 24 attached to the lamp housing 22, and a bulb 25 attached to the bulb socket 24 and arranged in the lamp chamber 21a.

The lamp housing 22 is made of, for example, butadiene rubber (abbreviated as BR) and a molecular weight of about 130,000.
Butagen acrylonitrile consisting of 150,000 acrylonitrile-styrene copolymer (abbreviated as AS)
A styrene resin (abbreviated as ABS resin, that is, B.AS resin) is used. The blending ratio of BR and AS can be appropriately set according to the type of lamp, welding conditions, etc., and if desired, other known resins and rubbers and known additions as other components of the B / AS resin. Agent,
For example, a plasticizer or the like can be included. Further, for the lens 23, for example, an acrylic resin made of a polymer having a molecular weight of 130,000 to 150,000 is used.

As shown in FIG. 2, the lamp housing 22 and the lens 23 are shown in FIG. 1 (b) and FIG. 3 (a) in a state before the lamp housing 22 and the lens 23 are welded (melted / fixed). The following step structure is provided for such welding.

<Step structure> That is, the lamp housing 22
As shown in FIGS. 1 (b) and 3 (a), the annular open end portion 22a (joined portion) has an inner annular thin portion 22b located on the inner peripheral side and an inner annular thin portion 22b. By providing 22b, an outer annular step bonding surface 22c formed on the outer peripheral side is provided.

Further, the lens 23 is integrally provided with an annular or tubular mounting leg 26 extending along the peripheral edge. At the annular open end 26a of the mounting leg 26, the inner annular thin portion 22
It is fitted to the outer peripheral side of b and the tip is an outer annular step joint surface 22c.
And a stepped surface 26c that faces the tip of the inner annular thin portion 22b at a distance from each other.

Further, the annular joining projection 26b has a tapered inner surface 26d whose diameter increases toward the tip, and a space 27 is formed between the tapered inner surface 26d and the inner annular thin portion 22b. There is. As a result, when the annular joint protrusion 26b is melted while being pressed by the outer annular step joint surface 22c, the molten resin is moved to the inner annular thin portion 22b side, that is, the space 27 by the action of the tapered inner surface 26d. Has become.

In addition, the distance L1 between the tip of the inner annular thin portion 22b and the step surface 26c is about 2 mm to 2.mm when the tip of the annular joining projection 26b is in contact with the outer annular step joining surface 22c.
Set to a value of 5 mm or in the vicinity thereof, and the annular joint protrusion 26b
The width L2 of the tip of is set to about 1 mm to 1.5 mm.

<Pressure Welding Means 30> The lamp housing 22 and the lens 23 of such a bulb case 21 are welded and fixed via the pressure welding means 30 shown in FIG. The pressure welding means 30 has a work holding pressure means 40 and a high frequency heating means 50.

The work holding / pressurizing means 40 includes first and second mold holding bases (not shown) provided so as to be relatively movable toward and away from each other, and a moving direction to the first and second mold holding bases. The first and second work holding dies 41 and 42 respectively mounted so as to be slightly movable within a predetermined range, and the work holding dies 41 interposed between the first die holding base and the work holding dies 41. Is provided between the second die holding base and the work holding die 42, and a biasing means, that is, a spring (not shown) for urging the spring toward the second work holding die 42 side. A spring (not shown) for urging 42 toward the first work holding die 41 side and a solenoid as a die driving means for driving the work holding dies 41, 42 toward and away from each other (see FIG. (Not shown) and the minimum of the work holding dies 41, 42 It is provided with a stopper (not shown) to regulate the interval.

In FIG. 1 (b), 41a and 42a are opposed surfaces of the work holding dies 41 and 42 facing each other, 41b is a housing holding recess provided in the work holding dies 41 and opened to the facing surface 41a, and 42b is a work. It is a lens holding recess provided in the holding mold 42 and opening to the facing surface 42a.

Further, the high-frequency heating means 50 is provided with brackets 51 made of an insulating material and fixed in a number of positions on the facing surface 41a along the housing holding recess 41b, and in a ring shape (annular shape) along the housing holding recess 41b. The magnetic conductive heating member 52 is provided and is held by the bracket 51, and the high frequency coil 53 is wound around the magnetic conductive heating member 52 at a pitch P and is held by the bracket 51.

A high frequency voltage is applied to the high frequency coil 53 through a control circuit (not shown) so that a high frequency current flows. Further, a metal material such as iron is used for the magnetically conductive heating member 52, and the distance A between the magnetically conductive heating member 52 and the high frequency coil 53 is 5 mm in order to increase the heating efficiency due to eddy current loss in the magnetically conductive heating member 52. Within the range, and the housing holding recess 42b of the work holding die 42
Lamp housing 22 and magnetically conductive heating member 5 held by
The distance B from 2 is also arranged so as to be close enough so that burrs due to the molten resin in the fusion-bonded portion do not adhere.

By constructing such a high-frequency heating means 50 in the work holding die 41 to heat the portions to be joined, the conventional pressure welding means using a hot plate (heating plate) can be used. Can be more compact than That is, there is an advantage that the work space is advantageous.

<Housing-Lens Joining Step and Other Configurations and Functions> In order to weld and fix the lamp housing 22 and the lens 23 of the bulb case 21 by using the pressure welding means 30 as described above, the first step is first. The work holding type 4 is a solenoid controlled by a control circuit (not shown).
1 and 42 are opened widely to hold the lamp housing 22 in the housing holding recess 41b and hold the lens 23 in the lens holding recess 42b.

Next, in the second step, the solenoid (not shown) is operated by the control circuit to bring the first and second die holding bases (not shown) closer to each other, thereby bringing the workpiece holding dies 41 and 42 closer to each other. , The annular joint projection 26b of the lens 23 is connected to the inner annular thin portion 2 of the lamp housing 22.
It is fitted to the outer peripheral side of 2b, and the annular joint projection 26b
The front end of the lamp housing 22 to the outer annular step joint surface 22
It is elastically contacted (pressurized) with the spring force of a spring (not shown).

At the time of this fitting, even if there are some dimensional variations in the width of the inner surface of the annular joint projection 26b and the width of the outer surface of the inner annular thin portion 22b, the tip of the annular joint projection 26b is tapered. Since the inner surface 26d is opened further outward than the inner annular thin portion 22b, the annular joining projection 26b can be easily fitted to the inner annular thin portion 22b by the action of the tapered inner surface 26d.

The elastic contact (pressurizing) force is the unit length (cm).
It is set to about 2 to 3 kg. At this time, the mating portion of the annular joining protrusion 26b and the outer annular step joining surface 22c faces the widthwise center of the magnetically conductive heating member 52 of the high-frequency heating means 50.

The positions of the work holding molds 41 and 42 in this state are detected by a detection means such as a micro switch (not shown), and this detection signal is input to the control circuit, and a high frequency AC voltage is applied to the high frequency coil 53 by the control circuit. Then, let the high-frequency alternating current flow. Note that this energization can be performed manually. Further, this energization should be started at the start of the relative approach operation state of the work holding dies 41, 42, or immediately before or immediately after the end of the operation, while the control circuit judges the control state of the work holding dies 41, 42. You can also

As a result, the change in the magnetic field generated around the high frequency coil 53 generates an eddy current in the magnetically conductive heating member 52, and the magnetically conductive heating member 52 is heated by the eddy current loss. At this time, a control circuit (not shown) controls the voltage and current applied to the high-frequency coil 53 so that the magnetically conductive heating member 52 is subjected to high-frequency induction heating at about 400 w per unit length (cm).

Radiant heat is radiated from the magnetically conductive heating member 52 that has been subjected to high-frequency induction heating in this manner, and this radiant heat is applied to the annular joint projection 26b of the lens 23 and the lamp housing 22.
The periphery of the outer annular step bonding surface 22c is heated.

At this time, the annular joint projection 26b of the lens 23 is formed.
Since the mating portion of the outer annular step bonding surface 22c of the lamp housing 22 faces the widthwise center of the magnetically conductive heating member 52, the mating portion and its vicinity are heated most strongly, and the thinnest annular bonding protrusion is formed. The tip of 26b begins to melt.
The radiant heating temperature by the magnetically conductive heating member 52 may be a temperature at which the most strongly heated tip of the annular joining projection 26b can be melted.

When the tip portion of the annular joining protrusion 26b begins to melt due to this radiant heating, the portion of the outer annular step surface 22c that contacts the tip portion of the annular joining protrusion 26b also begins to melt,
The annular joint projection 26b of the lens 23 and the lamp housing 2
The work holding die 4 is attached to the mating portion of the outer annular step bonding surface 22c of FIG.
Spring acting via 1, 42 (not shown)
The molten resin is moved to the space 27 side and the outer surface side of the mating portion by the spring force (pressing force). At this time, most of the molten resin is generated in the space 2 by the action of the pressing force and the tapered inner surface 26d.
It has been moved to the 7 side to prevent large burrs from forming on the outer surface of the mating part.

In this way, the tip of the annular joint projection 26b is melted by a predetermined length (for example, a set length in the range of 2 mm to 2.5 mm), and the lamp housing 22 and the lens 2 are melted.
When 3 is moved closer to each other, the work holding die 4
First and second stoppers (not shown) respectively provided on the first and second abutments stop the relative approach movement of the work holding dies 41, 42 by a spring (not shown), and the annular joint projection of the lamp housing 22 is stopped. 26b and the outer annular step bonding surface 22c of the lens 23 are fusion-bonded over the entire circumference. At this position, the inner annular thin portion 2 of FIG.
The distance L1 between the tip of 2b and the step surface 26c has a value in the range of 2 mm to 2.5 mm described above as shown in FIG. 3 (b).

When the contact between the stoppers is detected by a detection means such as a micro switch or an optical sensor (not shown),
A detection signal from this detection means is input to a control circuit (not shown), and this control circuit stops energization of the high frequency coil 53. The energization time to the high frequency coil 53 may be set in advance by a timer, and the energization may be stopped after a fixed time.

As a result, the distal end portion 26a of the mounting leg 26 of the lens 23 is integrally and airtightly welded and fixed to the annular open end portion 22a of the lamp housing 22 over the entire circumference by the fusion / fusion adhesion portion (joint portion) 60. . Then, at this time, as shown in FIG. 3B, at the fusion / fusion adhesion portion 60,
A burr 61 slightly protruding to the outer surface side is generated, but the burr 61 has a much smaller protruding amount than in the conventional case.

After this energization is stopped, the control circuit keeps the first and second stoppers (not shown) provided on the work holding dies 41 and 42 in contact with each other for a certain period of time to cure the molten portion. After that, a solenoid (not shown) is operated to open the work holding dies 41 and 42 widely, and the bulb case 21 (product) in which the lamp housing 22 and the lens 23 are joined is taken out.

In the embodiment described above, the annular joint projection 2
An example in which the tip of 6b has a certain width is shown in FIG.
As shown in (a), the tip of the annular joining projection 26b is formed at an acute angle so that the tip of the annular joining projection 26b begins to melt faster than other portions due to radiant heat, and the molten resin causes the space in FIG. The space 27 may be made easier to move and the space 27 may be filled with the molten resin to be in the state of FIG. 4B, so that the sealing property may be further improved.

In the embodiment described above, the annular joint projection 26b is provided on the lens 23 side and the inner annular thin portion 22b is provided on the lamp housing 22 side. However, the annular joint projection 26b is provided on the lamp housing side. Alternatively, the inner annular thin wall portion 22b may be provided on the lens 23 side.

Further, in the above-mentioned example, an example in which the straight (linear) high frequency coil 53 is wound along the ring-shaped magnetically conductive heating member 52 so as to be arranged in a coil shape is shown, but this is not always the case. It is not limited to. For example, as shown in FIG. 5, by winding the spiral (spiral) high-frequency coil 53 several times along the annular magnetically conductive heating member 52 (three times in FIG. 5A), You may arrange | position in a coil shape.

[0059]

As described above, according to the first aspect of the invention, the resin lamp housing that opens to one side and the resin lens are provided, and the peripheral edge portion of the lens is the annular open end portion of the lamp housing. While pressing the lens housing and the lens, the high-frequency heating means along the fitting portion of the lamp housing and the lens melts and fixes the fitting portion so that the lens and the lamp housing are hermetically joined. Therefore, it is possible to heat and melt the portion to be joined without directly contacting the heating means, and the number of steps for fusion joining the lamp housing and the lens can be reduced, which saves labor.

Further, by allowing the parts to be joined to be heated and melted without directly contacting the heating means, the conventional heating plate for melt-bonding the lamp housing and the lens can be omitted, and the equipment can be installed. Easy to do.

Further, by omitting the conventional heating plate for fusion-bonding the lamp housing and the lens, and heating and melting the joined parts without directly contacting the heating means, the conventional heating plate can be used. It is possible to prevent the occurrence of water leakage due to the carbonized resin.

Moreover, the melting margin of the jointed portion does not differ (disperse) with each heating and melting of the product by the heating means, so that the appearance of the jointed portion can be prevented from being impaired.

According to a second aspect of the present invention, the annular joint projection provided on one of the lamp housing and the lens is fitted to the outer peripheral side of the inner annular thin portion provided on the other side to form the outer annular step joint. Since the high-frequency heating means is used for melting and fixing while pressing against the surface, in addition to the above-mentioned effects, the molten resin of the annular joint projection is affected by the action of the inner annular thin-walled portion of the fitting portion of the lamp housing and the lens. The movement to the inner surface side is prevented, and the formation of burrs on the inner surface side is prevented.

Further, according to the invention of claim 3, a space is formed between the tapered housing inner surface of the annular joint projection provided on one side of the lamp housing and the lens and the inner annular thin portion provided on the other side. As a result, when the annular joining protrusion is melted by the high-frequency heating means while being pressed against the outer annular step joining surface, the molten resin is moved toward the inner annular thin portion side, that is, the space side by the action of the tapered inner surface. Since it is moved so that it hardly moves to the outer surface side of the fitting portion of the lamp housing and the lens, a large burr is hardly generated on the outer surface side when the joined portions are melt-bonded.

[Brief description of drawings]

FIG. 1 (a) is a partial cross-sectional plan view showing a cross-section of the device (b) used in the method for joining a lens and a housing of a vehicle lamp of the present invention along the line C-C, and FIG. (a) is a sectional view taken along the line D-D, (c) is a partially enlarged sectional view taken along the line EE of (a), and (d) is a right side view of (c).

FIG. 2 is a cross-sectional view of a vehicular lamp having a lens and a housing that are joined using the device shown in FIG.

3A is an enlarged sectional view of an essential part of FIG. 1B, and FIG. 3B is an enlarged sectional view of an essential part of FIG.

4 (a) and 4 (b) are enlarged cross-sectional views of a main part showing another example of FIGS. 3 (a) and 3 (b).

FIG. 5 is a cross-sectional view of a vehicular lamp including a lens and a housing that are joined together by a conventional joining method.

6A is an explanatory view showing another example of the high frequency coil shown in FIG. 1, and FIG. 6B is a side view of the high frequency coil shown in FIG.

7A to 7G are explanatory views of a joining process of a joining method of a lens and a housing of a conventional vehicle lamp, and FIG. 7H is an enlarged sectional view of a main part of FIG.

[Explanation of symbols]

 Reference numeral 20 ... Vehicle lamp 21 ... Bulb case 22 ... Lamp housing 22a ... Annular open end 22b ... Inner annular thin portion 22c ... Annular step joint surface 23 ... Lens 26 ... Mounting leg 26a ... Annular open end 26b ... Annular joint projection 26d ... tapered inner surface 30 ... pressurizing welding means 40 ... work holding pressurizing means 50 ... high frequency heating means

Claims (3)

[Claims] 1. A lamp housing and a lens made of resin which are open to one side are provided, and the lamp housing and the lens are pressed while the peripheral edge of the lens is pressed against the annular open end of the lamp housing. In a method of joining a lens and a housing of a vehicle lamp, wherein the lens and the lamp housing are airtightly joined by melting and fixing the joining portion with the high frequency heating provided along the joining portion. The lens and the housing of the vehicular lamp are joined air-tightly by heating the mating part by means to melt and fix the mating part. Method. 2. The lens integrally includes an annular mounting leg extending along a peripheral edge of the lens, and an inner annular ring is formed on one inner peripheral side of the annular open end of the mounting leg and the annular open end of the lamp housing. By providing the thin portion, the outer annular step joint surface is formed on the outer peripheral side of the one annular open end, and the outer annular step joint is fitted on the outer peripheral side of the inner annular thin portion and the outer annular step joint is formed. A thin annular joint protrusion engaging with the surface is integrally formed on the other of the annular open ends, and the annular joint protrusion is melted by the high-frequency heating means while being pressed against the outer annular step joint surface. The method for joining a lens and a housing of a vehicular lamp according to claim 1, wherein the lens and the housing are fixed. 3. The annular joint projection has a tapered inner surface whose diameter increases toward the tip, and the annular joint projection is melted by the high-frequency heating means while being pressed by the outer annular step joint surface. The method for joining a lens and a housing of a vehicular lamp according to claim 2, wherein the molten resin is moved to the inner annular thin-walled portion side at the time of heating.