JP5164888B2 - Single-piece fluorescent lamp and manufacturing method of single-piece fluorescent lamp - Google Patents

Description

  The present invention relates to a single-tube fluorescent lamp using a U tube, and at the ambient temperature of 25 ° C., the coldest point temperature, which is the lowest temperature in the discharge tube, is optimal in the correlation between self-heating and ambient temperature. Thus, the present invention relates to a single-piece fluorescent lamp and a single-piece fluorescent lamp manufacturing method in which the brightness of the lamp is maximized and mercury vapor pressure is not regulated by mercury amalgam. The present invention also includes a fluorescent lamp in which the discharge tube has at least one bent portion.

A conventional low-pressure discharge lamp using a U-tube is configured as shown in FIG. 6 and FIG. 7 showing a low-pressure discharge lamp bent once, and the arc tube 1 formed of a U-tube has two longitudinal directions. Tube sections 2, 3 and transverse tube section 4 are provided. U-shaped bent portion of the arc tube 1 has an outer generatrix M _Q in the transverse tube section 4 is linear, and configured to extend substantially perpendicular to the outer generating line M _L in both the longitudinal tube section 2 and 3 Has been. The diameter D _L of the longitudinal tube sections 2 and 3 is 12 mm, the diameter D _Q of the transverse tube section 4 is selected at its center and D _Q / _DL is approximately 1.2, It is sufficient that _DQ is equal to or larger than the diameter D _L. Furthermore, the tube transition between the longitudinal tube sections 2, 3 and the transverse tube section 4 extends such that the ratio of the diameter D _{LQ to} the diameter D _{Q at the} tube bend is about 1.2. The diameter D _LQ only needs to be larger than the diameter D _Q.

  FIG. 8 is a graph showing the temperature distribution of the low-pressure discharge lamp bent once in FIGS. 6 and 7 and measured at an ambient temperature of about 25 ° C. FIG. From the figure, the cold spot that determines the mercury vapor pressure during lamp operation is present in the tube bends 5 and 6 and its temperature is approximately 40 ° C. The temperature increases to 70 ° C. in the direction of the sealed end with the electrode. The central part of the transverse tube section 4 is 45 ° C., 5 ° C. higher than the cold spot.

  In this way, an optimum mercury vapor pressure is achieved during lamp operation by the cold spots in the outer tube bends 5,6.

  Further, as a method of manufacturing the U tube, first, a straight glass tube is heated, and in particular, the central portion of the tube is set to a softening point temperature. Subsequently, the tube portions extending laterally from the central portion are bent so as to face each other until they (longitudinal tube portions) are positioned in parallel to each other. After that, the pipe part bent in a U-shape (transverse pipe part with a transition to the vertical pipe section) is inserted into the mold, and at the same time, gas is injected into the pipe through the pipe end and molding is performed. (For example, refer to Patent Document 1).

Japanese Examined Patent Publication No. 2-53906 JP-A-60-91547 JP 2002-15701 A Japanese Utility Model Publication No. 57-57055 JP-A-1-189850 Japanese Patent Laid-Open No. 10-302719

  In a conventional low pressure discharge lamp using a U tube, the cold spot (the coldest point) that determines the mercury vapor pressure during lamp operation exists in the tube bending portions 5 and 6, but the bend system (straight glass tube). Therefore, the glass wall thickness of the tube bent portions 5 and 6 that are the coldest points becomes thinner than other portions, and the product is weak and easily damaged. In addition, the manufacturing defect rate is high.

  The glass wall thickness determines the coldest spot temperature under the specified measurement conditions when the ambient temperature is 25 ° C. and no wind is lit. However, in a lamp using a plurality of bent tubes called FHT, there are three U-shaped portions and six coldest spot candidates. There has been a problem that the glass thickness at the coldest point changes due to variations in the manufacturing process, and the lamp characteristics also vary.

  The present invention has been made to solve the above-described problems. The product strength can withstand physical distribution as a product, the manufacturing defect rate is not increased, and there are few variations in the temperature of the coldest point candidates, which are stable. An object of the present invention is to provide a single-piece fluorescent lamp capable of obtaining lamp characteristics and a method for manufacturing the single-piece fluorescent lamp.

  Another object of the present invention is to provide a fluorescent lamp that can withstand the physical distribution of products as a product, does not increase the manufacturing defect rate, and is suitable for the temperature at the coldest point and provides stable lamp characteristics.

The single-ended fluorescent lamp according to the present invention has a discharge path bent at least once, regulates the mercury vapor pressure in the tube by a normal coldest point without being controlled by an amalgam, and has a corner of a U-shaped bent portion. in single base fluorescent lamp portion becomes the coldest spot, when the glass wall thickness of the corner portion of the bent portion becomes the coldest spot t, the glass wall thickness of the non-bending portion and a t _0,
0.12mm ≦ _t ≦ t 0/5
It is characterized by satisfying the relationship.

  Moreover, the single-piece fluorescent lamp according to the present invention is characterized by having a tube outer diameter of 13 mm or less.

  The method for manufacturing a single-piece fluorescent lamp according to the present invention is characterized in that, in the single-piece fluorescent lamp manufacturing method according to claim 1, a U-shaped bent portion is formed by a joining method.

In the fluorescent lamp according to the present invention, the discharge tube has at least one bent portion, the mercury vapor pressure in the tube is regulated by the normal coldest point without being controlled by the amalgam, and the bent portion becomes the coldest point. In the lamp, when the glass thickness of the bent portion that becomes the coldest point is t and the glass thickness of the non-bent portion is t ₀ ,
0.12mm ≦ _t ≦ t 0/5
It is characterized by satisfying the relationship.

  The single-cap fluorescent lamp according to the present invention is configured as described above, so that the product strength can withstand physical distribution as a product, the manufacturing defect rate is not increased, and the temperature of a plurality of coldest spot candidates is small and stable. Characteristics are obtained.

  The manufacturing method of the single-piece fluorescent lamp according to the present invention is configured as described above, whereby the bent portion can be easily formed.

  The fluorescent lamp according to the present invention is configured as described above, so that the product strength can withstand physical distribution as a product, the manufacturing defect rate is not increased, the temperature at the coldest point is appropriate, and stable lamp characteristics are obtained. A lamp can be provided.

FIG. 2 shows the first embodiment, and is a diagram showing a configuration of a low-pressure mercury vapor discharge single-piece fluorescent lamp. FIG. 5 shows the first embodiment and is a partial cross-sectional view of one U-tube. It is a figure which shows Embodiment 1, and is a figure which shows the relationship between the glass thickness of the corner | angular part of a bending part, and the coldest point temperature. It is a figure which shows Embodiment 1, and is a figure which shows the ambient temperature characteristic (specific luminous flux, base upper side) of a low-pressure mercury vapor discharge one-piece fluorescent lamp FHT57-H type. It is a figure which shows Embodiment 2, and is a figure which shows the general | schematic flow in the case of manufacturing a U pipe by a joining system. It is a figure of the low pressure discharge lamp which has the edge part with the conventional nozzle | cap | die. It is sectional drawing of the low voltage | pressure discharge tube which has not attached the nozzle | cap | die provided with the conventional discharge tube bent once. It is a figure which shows the temperature distribution of the conventional low pressure discharge lamp.

Embodiment 1 FIG.
1 to 5 are diagrams showing Embodiment 1, FIG. 1 is a diagram showing a configuration of a single-piece fluorescent lamp, FIG. 2 is a partial sectional view of one U-tube, and FIG. 3 is a glass wall at a corner of a bent portion. FIG. 4 is a diagram showing the relationship between the thickness and the coldest spot temperature, and FIG. 4 is a diagram showing ambient temperature characteristics (specific luminous flux, upper side of the base) of the low-pressure mercury vapor discharge single-base fluorescent lamp FHT57-H type.

  The inventors have found that among the manufacturing variations, there are lamps with markedly different ambient temperature characteristics. This lamp had a temperature characteristic shifted to a high temperature side. The inventors have investigated the cause in order to suppress variations in product characteristics, and have found that the thickness of a corner of a certain bent portion is extremely thin. In other words, the coldest spot is not only that the temperature drops if the distance from the discharge path simply due to the dimension, but also that it is greatly influenced by the thickness of the glass.

As shown in FIG. 1, the entire structure of the single-piece fluorescent lamp (model name FHT57EX-N) is the same as the conventional one. However, the arc tube 1 uses three U tubes, and each U tube includes two longitudinal tube sections 2 and 3 and a lateral tube section 4. The tube outer diameter of the U tube is 12 mm.
However, the tube outer diameter of the U tube is not limited to 12 mm. This embodiment can also be applied to a tube having a larger diameter.

As shown in the partial cross-sectional view of FIG. 2, the coldest glass thickness of the tube bent portions 5 and 6 (corner portions of the bent portions) can be obtained as a product with a product strength that can withstand physical distribution, and the manufacturing process is defective. In order not to raise the rate, it is set to 0.12 mm or more, and the coldest part glass thickness is set to 1/5 or less of the glass thickness of the normal part (non-bent part). As a result, the designed lamp characteristics can be obtained. When the thickness is 0.12 mm or more, the product is weak and easily damaged, and the manufacturing defect rate is increased.
Therefore, when the glass thickness of the corner portion of the bent portion that becomes the coldest point is t and the glass thickness of the non-bent portion is t ₀ ,
0.12mm ≦ _t ≦ t 0/5
By satisfying the above relationship, the product strength can withstand physical distribution as a product, the manufacturing defect rate is not increased, and a plurality of coldest spot candidate temperature variations are small and stable lamp characteristics can be obtained.

FIG. 3 shows the results of measuring the coldest spot temperature at an ambient temperature of 25 ° C. for lamps having different glass thicknesses at the coldest spot. The wall thickness t ₀ of the glass tube of the single-piece fluorescent lamp (model name FHT57EX-N) used here is 1.2 mm.

Glass thickness t of the coldest point (corner portions of the bent portion) is, for example, those of the conventional 0.3 mm (t _0/4), which is the coldest point temperature 57 ° C.. When the glass wall thickness t it becomes thinner, 0.2mm _(t 0/6) ones 54 ° C. down 3 ° C. than the coldest point temperature of a conventional, 0.15 mm ones coldest point temperature prior 52 ° C., 5 ° C. lower than the above.

As shown in FIG. 4, according to the ambient temperature characteristics of the low-pressure mercury vapor discharge single-neck fluorescent lamp FHT57-H type (specific luminous flux, upper part of the metallic base), the specific luminous flux becomes maximum at the coldest spot temperature of 52 ° C. Therefore, the lamp is designed so that the coldest spot temperature is 52 ° C at an ambient temperature of 25 ° C. The glass thickness t at the corner of the bent portion that becomes the coldest point is 0.12 mm ≦ be made thin in the range of t ≦ t _0/5 becomes a powerful means of achieving it.

According to this embodiment, it has a discharge path bent into a U-shape at least once, and the mercury vapor pressure in the tube is regulated by a normal cold spot without being controlled by an amalgam, and the corner of the U-shaped bent portion parts in the single base fluorescent lamp comprising a coldest point (model FHT57EX-N), when the glass wall thickness of the corner portion of the bent portion becomes the coldest spot t, the glass wall thickness of the non-bending portion was t ₀ ,
0.12mm ≦ _t ≦ t 0/5
By satisfying this relationship, the product strength can withstand physical distribution as a product, the manufacturing defect rate is not increased, and there are few variations in temperature of a plurality of coldest spot candidates, and stable lamp characteristics can be obtained.

Embodiment 2. FIG.
FIG. 5 is a diagram showing the second embodiment, and is a diagram showing a schematic flow when a U-tube is manufactured by a joining method.
One U-tube is created by using two glass tubes having an outer diameter of 12 mm and a wall thickness of 0.75 mm (maximum 1.0 mm). First, the vicinity of one end of each linear glass tube is heated and melted with a burner, the melted portion is brought into contact with each other to form a U shape, and the U shape portion is further heated, and then fitted into a mold. An inert gas is poured from the opening, and molding is performed while applying pressure to form a desired shape.

Also in this case, the glass thickness at the corner of the bent portion is the same as in the first embodiment, where t is the glass thickness of the corner portion of the bent portion that becomes the coldest point, and t ₀ is the glass thickness of the non-bent portion. When
0.12mm ≦ _t ≦ t 0/5
The structure satisfying

However, the glass wall thickness _{t 0} of the non-bending portion, for example, in the case of 0.75 mm, the preferred range of the glass wall thickness t of the corner portion of the bent portion becomes the coldest point, for example, 0.12 mm ≦ t ≦ 0. 15 mm.

  When the U pipe is manufactured by the joining method, there is an advantage that molding is easy.

  In the first and second embodiments, the U-shaped bent portion is described, but the bent portion is not limited to the U-shape. For example, a U-shape may be used. In short, in the case of a single base, any shape may be used as long as it is bent by approximately 180 degrees.

In the first and second embodiments, the single-end fluorescent lamp has been described. However, the present invention can also be applied to fluorescent lamps other than the single-end base. For example, the discharge tube has at least one bent portion, and the mercury vapor in the tube Even in a fluorescent lamp in which the pressure is regulated by the normal coldest point without being controlled by an amalgam and the bent part is the coldest point, the glass thickness of the bent part that becomes the coldest point is t, and the glass meat of the non-bent part When the thickness is t ₀
0.12mm ≦ _t ≦ t 0/5
By satisfying the above relationship, it is possible to provide a fluorescent lamp in which the product strength can withstand physical distribution as a product, the manufacturing defect rate is not increased, the temperature at the coldest point is appropriate, and stable lamp characteristics can be obtained.

  1 Arc tube, 2, 3 Longitudinal tube section, 4 Transverse tube section, 5, 6 Tube bending part.

Claims (11)

A single-tube fluorescent lamp having a discharge tube having a discharge path having a bent portion bent, the corner portion of the bent portion being the coldest point,
Between two straight longitudinal tube sections extending in parallel, one transverse tube section connecting the two longitudinal tube sections, and between the longitudinal tube section and the transverse tube section Three U-tubes having a pair of bends,
A single base to which the three U pipes are attached so that the height of the three U pipes to the horizontal pipe section is the same.
The outer diameter of the discharge tube is 13 mm or less,
The corner portions of the six bent portions of the three U tubes are the coldest point candidates that become the coldest point, and the glass thickness of the coldest point candidate is t, and the glass thickness of the non-bent portion is t. _{When 0}
0.12mm ≦ _{t <t} 0/5
Satisfy the relationship
When the single-piece fluorescent lamp is lit at an ambient temperature of 25 ° C., the coldest spot temperature of the bent portion is 51.0 ° C. to 55.6 ° C.
t ₀ = 1.2 mm
A single-piece fluorescent lamp characterized by 0.12 mm ≦ t < 0.24 mm.   The single-necked fluorescent lamp according to claim 1, wherein the coldest spot candidate is formed at a position lower than a maximum height of the U tube to the horizontal tube section. The three U pipes are arranged in a single base so that a substantially equilateral triangle can be formed by a transverse pipe section of the three U pipes,
The coldest spot candidate is in the middle of each side of the substantially equilateral triangle formed by the lateral pipe sections of the three U pipes, and inside the common tangent line of the vertical pipe sections of the adjacent U pipes. The single-piece fluorescent lamp according to claim 1 or 2, wherein the single-piece fluorescent lamp is formed. In a one-piece base fluorescent lamp having a discharge path having a bent portion bent, the corner portion of the bent portion being the coldest point,
Between two straight longitudinal tube sections extending in parallel, one transverse tube section connecting the two longitudinal tube sections, and between the longitudinal tube section and the transverse tube section Three U-tubes having a pair of bends,
A single base to which the three U pipes are attached so that the height of the three U pipes to the horizontal pipe section is the same.
The bent portion connects the longitudinal tube section and the transverse tube section in a vertical direction;
The corner portion of the bent portion is formed at a position lower than the maximum height of the U pipe to the lateral pipe section, and is formed inside a common tangent line of the vertical pipe section of the adjacent U pipe,
The longitudinal tube section has an outer diameter of 13 mm or less;
When the glass thickness of the corner portion of the bent portion is t and the glass thickness of the non-bent portion is t ₀ , the coldest spot of the bent portion when the one-piece fluorescent lamp is lit at an ambient temperature of 25 ° C. So that the temperature is between 51.0 ° C and 55.6 ° C.
t ₀ = 1.2 mm
A single-piece fluorescent lamp characterized by 0.12 mm ≦ t ≦ 0.24 mm. The bent portion connects the longitudinal tube section and the transverse tube section in a vertical direction;
The single-piece fluorescent lamp according to any one of claims 1 to 4, wherein a radius of curvature of a corner portion of the bent portion is smaller than a radius of curvature of the longitudinal tube section. The glass thickness of the longitudinal tube sections is t _0,
Said bent portion, the glass surface of the inner of the bent portion is close to the glass surface of the outer bent portion, the glass thickness t of the corner portion of the bent portion is 0.12mm ≦ t <t _0/5 The single-piece fluorescent lamp according to any one of claims 1 to 5.   The single-piece fluorescent lamp according to any one of claims 1 to 6, wherein the single-piece fluorescent lamp is an FHT single-piece fluorescent lamp.   The single-piece fluorescent lamp according to any one of claims 1 to 7, wherein the corner portion of the bent portion is a thin portion formed by extending the discharge path in the angular direction of the bent portion. Between two straight longitudinal tube sections extending in parallel, one transverse tube section connecting the two longitudinal tube sections, and between the longitudinal tube section and the transverse tube section In the method of manufacturing a single-ended fluorescent lamp having a U-tube having a pair of bent portions, a bent discharge path, and a corner portion of the bent portion being the coldest point,
Heating the U-shaped part of the glass tube having the U-shaped part, and fitting the heated U-shaped part into a mold;
After the step of fitting into the mold, pressurized gas is blown from the opening of the glass tube, the U-shaped portion is expanded by the pressurized gas, and the U-shaped portion is formed into a U-shape, and the coldest spot is formed at the corner of the U-shape. Forming a bent portion to form a U tube;
An attaching step of attaching three U tubes to a single base so that the height of the three U tubes to the transverse tube section is the same after the step of forming the U tubes;
The longitudinal tube section has an outer diameter of 13 mm or less;
When the glass thickness of the corner portion of the bent portion is t and the glass thickness of the non-bent portion is t ₀ , the coldest spot of the bent portion when the one-piece fluorescent lamp is lit at an ambient temperature of 25 ° C. So that the temperature is between 51.0 ° C and 55.6 ° C.
t ₀ = 1.2 mm
The manufacturing method of the single-piece | base metal fluorescent lamp characterized by being set to 0.12 mm <= t <= 0.24mm. The step of forming the U-tube includes
From the U-shaped portion, the bent portion is formed into an L shape so that the one transverse tube section and the two longitudinal tube sections are in a vertical direction, and the portion formed into an L shape The method of manufacturing a single-ended fluorescent lamp according to claim 9, wherein the corner portion that becomes the coldest point is formed by inflating the outermost portion in a corner outward direction.   Before the step of fitting into the mold, the method includes a step of manufacturing a glass tube having the U-shaped portion by melting one end of each of two straight glass tubes and bringing the melted portions into contact with each other. The method for producing a single-piece fluorescent lamp according to claim 9 or 10.

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