JP2965920B2 - Single terminal type discharge lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp, and more particularly, to a light source for a vehicle headlamp.
Alternatively, the present invention relates to a single-terminal discharge lamp provided with a base at one end for use as a light source for a liquid crystal projector.

[0002]

2. Description of the Related Art As a configuration of a conventional one-terminal type discharge lamp of this type, for example, as shown in Japanese Patent Application Laid-Open No. 8-64114, a so-called self-centering And mounting the holder member to a cylindrical socket, adjusting the depth and direction, and then welding the holder member and the socket portion.

[0003]

However, in the above-mentioned conventional construction, first, two members, ie, a holder member and a socket part, are required as a base, which complicates the construction and increases the cost. Attachment between the burner and the holder member and attachment between the holder member and the socket portion require two attachment steps, which increases the number of steps and also raises the problem of cost increase. .

[0004] Secondly, two joints between the burner and the holder and between the holder and the socket are formed in the socket as described above, which requires dimensions for the joint. The interval between the lead wires connected to the two electrodes in the socket portion becomes narrow, and there is also a problem that the dielectric strength against a high voltage required for lighting the discharge lamp is insufficient.

Third, since the outer shape of the holder member is spherical, contact with the socket portion is made at a linear portion, that is, the welding area is small. For example, there is a problem that mechanical strength is insufficient, such as separation of the holder member from the socket portion due to vibration or impact during running of the automobile, and solving these points has been an issue.

[0006]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, a thermoplastic socket is attached to one end of a burner comprising a discharge tube and a jacket tube. In the single-terminal discharge lamp, the socket is provided with a cylindrical holder that fits in the burner in the radial direction along the installation direction of the burner, and the holder has the diameter of the holder. By mounting a holder spring made of metal in a substantially circular shape having a biasing force in the direction of pressing against the burner, inserting one end of the burner into the holder portion and setting it to a predetermined position, and then performing high-frequency heating. The problem is solved by providing a single-terminal discharge lamp characterized in that the holder is melted by the heat generated by the holder spring and the burner and the socket are engaged with each other. It is intended.

[0007]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. 1 and FIG.
What is indicated by is a single-terminal discharge lamp according to the present invention,
This single-terminal discharge lamp 1 is constructed by welding a socket 3 made of a thermoplastic resin to one end of a burner 2 consisting of a discharge tube 2a and a jacket tube 2b by welding. It is similar to the example.

Here, in the present invention, the holder portion 4 is integrally formed inside the socket 3, and at this time, the holder portion 4 has a cylindrical shape extending from the bottom surface 3a of the socket 3 along the installation direction of the burner 2. And the inner diameter thereof can be fitted to the outer diameter of the burner 2.

The outer diameter of the holder portion 4 is formed of a member having appropriate elasticity, such as a steel material or a spring material, for example, and a holder spring 5 formed to have a biasing force in the direction of reducing the diameter. Is attached. At this time, the biasing force of the holder spring 5 does not need to be so strong as long as it can compress the diameter of the holder portion 4 during welding described later.

In the figure, reference numeral 7 denotes a burner 2
The lead wires provided at both ends of the burner 2 are denoted by reference numeral 8 and are ceramic plates provided for the purpose of protecting the socket 3 from heat generated when the burner 2 is turned on.
Reference numeral 9 denotes a lead wire 7 on the opposite side of the socket 3
Is a ceramic tube that insulates.

When attaching the burner 2 to the socket 3 formed as described above, first, one end of the burner 2 is inserted into the inner diameter of the holder portion 4. At this time, since the holder portion 4 is provided along the installation direction of the burner 2, the center line of the burner 2 with respect to the socket 3 is set as a design position.

Accordingly, if the depth of insertion of the burner 2 into the holder portion 4 is adjusted with reference to the flange 3b of the socket 3, the discharge chamber 2c of the burner 2 will be at a predetermined position. Here, since the holder spring 5 does not have a biasing force enough to compress the diameter of the holder part 4, the burner 2 can slide freely in the holder part 4.

When a predetermined position is obtained in the discharge chamber 2c in this way, when the state is maintained and the socket 3 is subjected to high-frequency heating, the holder spring 5 is heated by dielectric, and this heat is transferred to the holder. The heat is conducted to the part of the holder part 4 which is in direct contact with the spring 5 and is heated.

The holder 4 made of a thermoplastic resin is softened and melted by this heating, and the diameter thereof is reduced by the biasing force of the holder spring 5 to be pressed against the burner 2 so that the burner 2 and the holder are pressed. The part 4 is to be welded. Then, if the high-frequency heating is stopped at an appropriate point, the once softened and melted holder portion 4 is hardened again and fixed between the burner 2 and the holder portion 4 by welding.

Next, the operation and effects of the single-terminal discharge lamp 1 of the present invention having the above-described configuration will be described.
First, the holder portion 4 is provided on the bottom surface 3a of the socket 3.
Is attached, the socket 3 and the holder 4 can be integrally formed by a mold or the like.

Therefore, it is not necessary to prepare the holder part 4 as a separate part, and the number of parts can be reduced.
The process of attaching the burner 2 to the holder portion 4 is a process of attaching the burner 2 to the socket 3, and the number of steps can be reduced at the same time.

Second, the above structure allows the burner 2 to be joined to the socket 3 at one place, and
Since the volume prepared for joining in the socket 3 is reduced, the interval between the lead wires 7 connected to both electrodes of the single-terminal discharge lamp 1 when passing through the socket 3 can be set wide. Thus, a sufficient dielectric strength can be given to a high voltage at the time of lighting.

Thirdly, the burner 2 and the holder 4 (socket 3) are welded to each other over a large area of a cylindrical surface. For example, vibrations and shocks during running of the automobile are applied. As well as burner 2 and holder 4
(Socket 3) and a sufficient joining strength that does not cause detachment between them can be obtained.

FIG. 3 shows another embodiment of the present invention. In the previous embodiment, the outer diameter of the burner 2 was inserted into the inner diameter of the holder portion 4 and the two were fitted together. However, the present invention is not limited to this, and the fitting may be performed by inserting the outer diameter of the holder 4 into the inner diameter of the burner 2 as shown in the figure.

At this time, the holder spring 6 is mounted on the inner diameter side of the holder portion 4 as having a biasing force in the direction of increasing the diameter, that is, generating a biasing force in the direction in which the burner 2 exists. In this case, the holder portion 4 is enlarged and welded by high frequency heating.

[0021]

As described above, according to the present invention, the socket is provided with a cylindrical holder portion that fits radially with the burner along the installation direction of the burner, and the holder portion is provided with the holder. A holder spring made of metal is attached in a substantially circular shape having a biasing force in a direction in which the diameter of the part is pressed against the burner. By melting the holder part by the heat generated by the holder spring and performing the engagement between the burner and the socket, the first step is to reduce the number of parts. The welding required at two locations in the conventional example is reduced to a single location, reducing man-hours, and has an extremely excellent effect in reducing the cost of this type of single-terminal discharge lamp. That.

Secondly, the above configuration allows the burner to be joined to the socket at only one place, and reduces the volume required for joining in the socket. The spacing between the lead wires connected to both electrodes of the lamp when passing through the socket can be set wider, and it provides sufficient dielectric strength against high voltage during lighting, thus improving performance. It has the effect.

Third, the burner and the holder (socket) are welded to each other over a large area of the cylindrical surface. For example, even if vibrations and shocks are applied when the automobile is running, This provides sufficient bonding strength that does not cause separation of the bonding between the burner and the holder, and also has an excellent effect on improvement of reliability.

[Brief description of the drawings]

FIG. 1 is a partially exploded perspective view showing an embodiment of a one-terminal discharge lamp according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view showing a main part of another embodiment of the single-terminal discharge lamp according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... One terminal type discharge lamp 2 ... Burner 2a ... Discharge tube 2b ... Jacket tube 2c ... Discharge chamber 3 ... Socket 3a ... Bottom surface 3b ... Flange 4 ... Holder part 5, 6 ... Holder spring 7 Lead wire 8 Ceramic plate 9 Ceramic tube

Claims (3)

(57) [Claims] 1. A one-terminal type discharge lamp in which a thermoplastic socket is attached to one end of a burner comprising a discharge tube and a jacket tube, wherein the socket is fitted to the burner in a radial direction. The holder is provided along the installation direction of the burner, and the holder is provided with a holder spring made of metal in a substantially circular shape having a biasing force in a direction in which the diameter of the holder is pressed against the burner. The holder is melted by the heat generated by the holder spring by performing high frequency heating after inserting one end of the burner into the holder and positioning it at a predetermined position, and the burner and the socket are engaged. The one-terminal type discharge lamp characterized by the above-mentioned. 2. The fitting between the burner and the holder portion,
2. The single-terminal discharge lamp according to claim 1, wherein the discharge is performed between the outer diameter of the burner and the inner diameter of the holder. 3. The fitting between the burner and the holder part is as follows.
2. The single-terminal discharge lamp according to claim 1, wherein the discharge is performed between the inner diameter of the burner and the outer diameter of the holder.