CN202363411U - Ceramic electric arc tube with isothermal structure - Google Patents

Abstract

The utility model discloses a ceramic electric arc tube with an isothermal structure. The ceramic electric arc tube comprises a discharge cavity, an electrode tube arranged on the two sides of the discharge cavity, and an electrode assembly extending into the discharge cavity via the electrode tube. The discharge cavity is a non-homogeneous even-order isothermal curved surface cavity. According to the non-homogeneous even-order isothermal curved surface cavity, some relations are that a:b>=1, c:b>1, and cn:cn-1>=5, wherein x, y and z represent parameter variables of the curved surface of the discharge cavity, a and b represent the half long axis and the half short axis of the curved surface of the discharge cavity, and the values of a and b depend on requirements of power. According to the utility model, the uniformity and the consistency of the internal properties of the electric arc tube are effectively guaranteed, and the luminous efficiency, the color rendering and the service life of the electric arc tube are improved.

Description

Ceramic arc tube with isothermal structure

Technical field

The utility model relates to a kind of ceramic arc tube with isothermal structure, especially is applied to ceramic gold-halogen lamp or ceramic projection lamp.

Background technology

The ceramic discharge chamber is the critical component of ceramic arc tube, transparent ceramic material that ceramic material is selected for use such as aluminium oxide, nitrogen oxide aluminium, yttrium-aluminium-garnet (YAG) etc.The structure of ceramic arc tube directly influences the performance and the manufacture craft of lamp.Under the operating power of given lamp, the shape and size of ceramic arc tube have determined the working temperature of earthenware, and working temperature has determined the operating air pressure of luminescent substance.The operating air pressure of luminescent substance and the electrical quantity of light source, like tube voltage, and optical parameter, like light efficiency, color rendering etc. have direct relation.

The structure of electric arc tube is directly relevant with the stress that electric arc tube bears.Stress comes from two parts, and the one, in the forming and sintering process, itself bring, the camber line that reduces small curve can help to reduce this stress; Because temperature gradient is brought, this just requires in design, to accomplish uniformity of temperature profile to another kind of stress as far as possible when lamp is worked.Yet existing ceramic arc tube all fails to propose a kind of ceramic arc tube with isothermal structure.

The utility model content

To the shortcoming of prior art, the purpose of the utility model provides a kind of uniformity and consistency that guarantees the inner character of electric arc tube, helps to improve the ceramic arc tube with isothermal structure in its light efficiency, color rendering and life-span.

For realizing above-mentioned purpose; The technical scheme of the utility model is: a kind of ceramic arc tube with isothermal structure; Comprise discharge cavity, be located at the electrode tube on discharge cavity both sides and stretch into the electrode assemblie in the discharge cavity through electrode tube, this discharge cavity is four isothermal curved surface cavitys nonhomogeneous.

Such curved surface has guaranteed the uniformity and the consistency of the inner character of electric arc tube, the most reasonably reduces the structural stress of electric arc tube.Cavity design is different from adopted cylinder, spheroid or pure spheroid shape.The inner surface of cavity is designed to isothermal level and the isobaris surface near electric arc tube work.Because temperature is deferred to the second differential equation, considers that simultaneously electrode is a linear distribution, actual isothermal level is the quartic surface nonhomogeneous that contains quadratic term, promptly because the isothermal surface of linear arc-distribution correction.Such curved design can be born the pressure capability maximum so that the temperature gradient of electric arc tube is minimum, helps to improve the light efficiency of lamp, color rendering and life-span.

This idol nonhomogeneous time curved surface cavity is:

${\left(\frac{x}{a}\right)}^2+{\left(\frac{\sqrt{{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HSA00000157487800011.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2}}{b}\right)}^2+\underset{n=2}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{\left(\frac{\sqrt{{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HSA00000157487800011.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2}}{c_n}\right)}^{2n}=1,$

Wherein x, y, z represent the parametric variable of discharge cavity curved surface, and a, b are the semi-major axis and the semi-minor axis of discharge cavity curved surface, and its numerical value is decided by power requirement, and a:b>=1, c ₂: b＞1, c _n: c _N-1>=5.

Further, this quartic surface cavity nonhomogeneous is:

${\left(\frac{x}{a}\right)}^2+{\left(\frac{\sqrt{{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HSA00000157487800011.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2}}{b}\right)}^2+{\left(\frac{\sqrt{{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HSA00000157487800011.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2}}{c}\right)}^4=1,$

Wherein x, y, z represent the parametric variable of discharge cavity curved surface, and a, b are the semi-major axis and the semi-minor axis of discharge cavity curved surface, and its numerical value is decided by power requirement, and a:b >=1, c:b＞1.

Isothermal level mathematical description explanation: for a heat point source; Its isothermal level that produces heat is a sphere; Promptly

wherein x, y, z represent the parametric variable of discharge cavity curved surface, and a is the radius of sphere.Its thermal source of general ceramic lamp is electric arc and the electrode itself between pair of electrodes; Its thermal source axial dimension is greater than lateral dimension; So its isothermal level that produces heat is near ellipsoid; Promptly or

wherein x, y, z represent the parametric variable of discharge cavity curved surface; And a, b are the semi-major axis and the semi-minor axis of Ellipsoidal Surface; A:b>=1, promptly electrode axis to yardstick greater than horizontal yardstick.And when electrode spacing was big, when promptly thermal source was long linear heat source, one section temperature became milder in the middle of the thermoisopleth, and the description of isothermal level in this case is the correction of ellipsoid.Consider the axial symmetry of thermal source and the minute surface symmetry of median plane, quadratic power equation has originally increased even time high order correction term, Mainly be the correction of biquadratic item, wherein c generally speaking _n: b is more little, revise big more, i.e. ellipsoid interlude more " flattening ".So, the ceramic lamp c of long electrode distance _n: b is less, and the ceramic lamp of short pole span, like the c of ceramic projection lamp _n: b is bigger.

Further, the semi-major axis scope of discharge cavity curved surface is 2mm＜a＜10mm.

The isothermal surface of this discharge cavity is extended to and electrode tube inwall junction by the discharge cavity inwall, lets interface portion formation horn mouth structure bring " cold spot " to remove other technologies.Wall thickness such as prior art discharge cavity and electrode tube so that at it both intersection's shape flare openings, cause cold spot.This utility model also is to abide by the design of isothermal level in this point, continues up to the electrode tube part, has eliminated the cold spot on the electric arc tube inwall like this.

This electrode tube comprises interior pipeline section and the welding groove that is connected, and pipeline section is near discharge cavity in this, and welding groove is positioned at the end, and the interior pipeline section of the internal diameter of welding groove is big, and welding groove is realized the gas-tight seal of discharge cavity through filling scolder.In this programme, the end that is employed in electrode tube forms a welding groove structure, and the mouth of pipe is transferred to by the electrode tube wall in sealing-in position in the past, and the diameter of the mouth of pipe is bigger, greatly facilitates to put scolder and accomplish sealing-in.And scolder melts and the completion sealing-in at welding groove basically, and need not accomplish sealing-in through the quite long electrode tube wall that flow to.In addition, further from the high arc temperature district, the length of electrode tube can correspondingly reduce scolder, helps some to the shorter and smaller application of electric arc tube yardstick requirement compared with the technology of welding in existing prior art.The cold junction position of this scheme can effectively be controlled forward, owing to more near the thermal source part, improved cold junction temperature, guarantees the operating pressure of light source.

This electrode assemblie comprises tungsten plug, cermet rod and the lead-in wire that is connected successively; This tungsten plug stretches in the discharge cavity; This cermet rod is positioned at pipeline section; And the external diameter of cermet rod is suitable with the internal diameter of interior pipeline section, and lead-in wire stretches out outside the electrode tube with the terminal scolder that is connected and passes in the welding groove of cermet rod.Because the electrode tube inwall does not have the function of welding, electrode tube and electrode assemblie can reduce the gap as much as possible, the loss that brings to stop mercury and halide entering electrode tube gap.Because mainly in interior pipeline section, its function is the conduction of carrying electric current and stopping heat effectively to the cermet rod part.Add a lead-in wire, be used for joining with external circuit.The coefficient of expansion of this cermet rod and electrode tube are very approaching, can effectively avoid because the coefficient of expansion of electrode tube or conducting rod is inconsistent, and the electrode tube that causes break or has the gap.Less clearance has prevented effectively that luminescent substance such as halide and mercury from getting into the gap and the loss and the light efficiency attenuating that causes thus and the change in color of light of the luminescent substance that brings.

Perhaps; This electrode assemblie comprises tungsten plug, conducting rod and the contact tube that is connected successively; This tungsten plug stretches in the discharge cavity; This conducting rod is positioned at pipeline section, and the internal diameter of the external diameter of conducting rod and interior pipeline section is suitable, this contact tube and conducting rod be terminal is connected and pass scolder in the welding groove stretch out electrode tube outward and lead-in wire join.

This cermet rod end is provided with the boss structure that cooperates the location with welding groove.During sealing-in, electrode assemblie is injected in the electrode tube, because the effect of boss structure; Electrode assemblie can be positioned at predeterminated position well; Behind the plug-in mounting, again filler is filled on the solder bath, in this scheme; Because scolder is not to be filled in the gap of electrode assemblie and electrode tube, can effectively reduce the complexity of sealing technology.This boss structure outside end face is formed with the some kinds of conical surfaces, makes easier wetting welding groove of scolder and electrode.

Further, come off by solder bath for preventing the aging back of scolder, this welding groove be an outside throat structure or this welding groove side be provided with some recessed/the tongue structure.

The positive camber of this discharge cavity and the junction of electrode tube are the smooth transition structure, avoid acute angle curvature, to reduce the stress of ceramic arc tube.

Description of drawings

Fig. 1 is the framework sketch map that the utlity model has the ceramic arc tube of isothermal structure;

Fig. 2 is the profile that the utlity model has the ceramic arc tube of isothermal structure;

Fig. 3 is not for the profile of the ceramic arc tube of boss structure;

Fig. 4 is the profile of the ceramic arc tube of circular platform type for boss structure;

Fig. 5 is the profile of square ceramic arc tube for boss structure;

Fig. 6 has the profile of the ceramic arc tube of isothermal structure for embodiment 2;

Fig. 7 is c ₂: the structural representation of the shell of the ceramic arc tube during b=1.5.

Embodiment

Below in conjunction with embodiment and accompanying drawing the utility model is carried out detailed description.

As shown in Figure 1; The utility model discloses a kind of ceramic arc tube with isothermal structure; Comprise discharge cavity 18, be located at the electrode tube 15 on discharge cavity 18 both sides and stretch into the electrode assemblie in the discharge cavity 18 through electrode tube 15, this discharge cavity 18 is an idol nonhomogeneous time isothermal curved surface cavity.

This idol nonhomogeneous time curved surface cavity is:

wherein present embodiment with the biquadratic item be modified to the example explanation

${\left(\frac{x}{a}\right)}^2+{\left(\frac{\sqrt{{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HSA00000157487800011.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2}}{b}\right)}^2+{\left(\frac{\sqrt{{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HSA00000157487800011.png"\; state="\{\{state\}\}">y</figure-callout>}}^2+z^2}}{c}\right)}^4=1,$

Wherein x, y, z represent the parametric variable of discharge cavity curved surface, and four items in the curved surface in the equation make curved surface shrink to symmetry axis x axle at y axle and z direction of principal axis.A, b are the semi-major axis and the semi-minor axis of discharge cavity curved surface, and its numerical value is decided by power requirement, and a:b >=1, c:b＞1.This correction of isothermal level is because as the next correction of the linear zonation of the electric arc of thermal source.Wherein the c parameter is generally greater than the numerical value of a and b.As shown in Figure 7, be c ₂: the structural representation of the shell of the ceramic arc tube during b=1.5.

Further, the semi-major axis scope of discharge cavity 18 curved surfaces is 2mm＜a＜10mm.

Electric arc tube is to be the axially symmetric structure of axle with the pair of electrodes assembly, because heat is mainly from discharge cavity, the mathematic(al) representation of discharge cavity isothermal surface is a quartic surface, promptly contains the axisymmetric curved surface with quadratic term simultaneously four times.

The isothermal surface of this discharge cavity 18 is extended to and electrode tube inwall junction by the discharge cavity inwall.

Extremely shown in Figure 5 like Fig. 2; This electrode tube 15 comprises interior pipeline section 19 and the welding groove 13 that is connected, and pipeline section 19 is near discharge cavity 18 in this, and welding groove 13 is positioned at the end; And the interior pipeline section of the internal diameter of welding groove 13 19 is big, and welding groove 13 is realized the gas-tight seal of discharge cavities 18 through filling scolder 12.This discharge cavity 18 and electrode tube 15 have adopted transparent ceramic material.

In this programme, the end that is employed in electrode tube 15 forms a welding groove 13 structures, and the mouth of pipe is transferred to by the electrode tube wall in sealing-in position in the past, and the diameter of the mouth of pipe is bigger, greatly facilitates to put scolder and accomplish sealing-in.In addition, further from the high arc temperature district, the length of electrode tube can correspondingly reduce scolder, helps some to the shorter and smaller application of electric arc tube yardstick requirement compared with the technology of welding in existing prior art.The cold junction position 20 of this scheme can effectively be controlled forward, owing to more near the thermal source part, improved cold junction temperature, guarantees the operating pressure of light source.The junction of discharge cavity inwall and electrode tube also usually is called as cold junction owing to apart from electric arc and electrode tip farthest, generally be surface the coldest in the discharge cavity.

This electrode assemblie comprises tungsten plug 16, the cermet rod 14 that is connected successively and goes between 11; This tungsten plug 16 stretches in the discharge cavity 18; This cermet rod 14 is positioned at pipeline section 19; And the internal diameter of the external diameter of cermet rod 14 and interior pipeline section 19 is suitable, and lead-in wire 11 stretches out outside the electrode tube 15 with the cermet rod 14 terminal scolders that are connected and pass in the welding groove 13.Because 15 walls not have the function of welding in the electrode tube, electrode tube 15 can reduce the gap as much as possible with electrode assemblie, the loss that brings to stop mercury and halide entering electrode tube 15 gaps.Electrode tube 15 inwalls can add the outer surface processing of cermet rod 14 through grinding, interior polishing, and the gap between them can be controlled at the precision less than 2 microns.Such precision helps improving the life-span of ceramic arc tube and has increased the axiality of making electrode assemblie in the lamp process, guarantees the center of electric arc at ceramic arc tube.The electric arc of avoiding departing from can cause the departing from of ceramic arc tube isothermal, even brought local overheated of lamp and influence the result of use and the life-span of lamp.

This cermet rod 14 adds a lead-in wire 11, is used for joining with external circuit.The coefficient of expansion of this cermet rod 14 and electrode tube 15 are very approaching, can effectively avoid because the coefficient of expansion of electrode tube 15 or conducting rod 14 is inconsistent, and the electrode tube 15 that causes break or has the gap.

These cermet rod 14 ends are provided with the boss structure 17 that cooperates the location with welding groove 13.During sealing-in, electrode assemblie is injected in the electrode tube 15, because the effect of boss structure 17, electrode assemblie can be positioned at predeterminated position well, behind the plug-in mounting, filler 12 is filled on the solder bath 13 again, and lead-in wire 11 passes from scolder 12 again.In this scheme,, can effectively reduce the complexity of sealing technology because scolder 12 is not to be filled in the gap of electrode assemblie and electrode tube 15.

These boss structure 17 tops are formed with the some kinds of conical surfaces, make easier wetting welding groove of scolder and electrode.This boss structure 17 can become circular platform type or square structure.

Further, come off by solder bath 13 for preventing the aging back of scolder 12, this welding groove 13 is an outside throat structure, and throat structure applies an axial pressure to the overall structure of scolder 12, can prevent effectively that it from coming off.

Further, this welding groove 13 can be frustum cone structure or spherical structure.

Likewise, also can be provided with on these welding groove 13 sides some recessed/the tongue structure, groove/tongue structure has grasp to scolder integral body, can prevent effectively that the aging back of scolder 12 from being come off by solder bath 13.

Further, the internal diameter size of this welding groove 13 is in 1 to 5 millimeter scope, and the degree of depth is at 1 to 5 millimeter, and interior pipeline section 19 internal diameters are in 0.4-1.5 millimeter scope.

The junction 21 of the positive camber of this discharge cavity 18 and electrode tube 15 is the smooth transition structure, avoids acute angle curvature, to reduce the stress of ceramic arc tube.

Embodiment 2

As shown in Figure 6; Present embodiment is close with the structure of embodiment 1, and its difference is that this electrode assemblie comprises tungsten plug 16, conducting rod 14 and the contact tube 22 that is connected successively; This tungsten plug 16 stretches in the discharge cavity 18; This conducting rod 14 is positioned at pipeline section 19, and the internal diameter of the external diameter of conducting rod 14 and interior pipeline section 19 is suitable, and this contact tube 22 and conducting rod 14 be terminal to be connected and to pass scolder 12 in the welding groove 13 and stretch out that electrode tube 15 is outer 11 to join with going between.

Claims (10)

1. the ceramic arc tube with isothermal structure comprises discharge cavity, is located at the electrode tube on discharge cavity both sides and stretches into the electrode assemblie in the discharge cavity through electrode tube, it is characterized in that, this discharge cavity is an idol nonhomogeneous time isothermal curved surface cavity.

2. the ceramic arc tube with isothermal structure according to claim 1 is characterized in that, this idol nonhomogeneous time curved surface cavity is:

${\left(\frac{x}{a}\right)}^2+{\left(\frac{\sqrt{y^2+z^2}}{b}\right)}^2+\underset{n=2}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{\left(\frac{\sqrt{y^2+z^2}}{c_n}\right)}^{2n}=1,$

Wherein x, y, z represent the parametric variable of discharge cavity curved surface, and a, b are the semi-major axis and the semi-minor axis of discharge cavity curved surface, and its numerical value is decided by power requirement, and a:b>=1, c ₂: b＞1, c _n: c _N-1>=5.

3. the ceramic arc tube with isothermal structure according to claim 1; It is characterized in that this idol nonhomogeneous time curved surface cavity is:

Wherein x, y, z represent the parametric variable of discharge cavity curved surface, and a, b are the semi-major axis and the semi-minor axis of discharge cavity curved surface, and its numerical value is decided by power requirement, and a:b >=1, c:b＞1.

4. according to claim 2 or 3 described ceramic arc tubes, it is characterized in that the semi-major axis scope of discharge cavity curved surface is 2mm＜a＜10mm with isothermal structure.

5. the ceramic arc tube with isothermal structure according to claim 4 is characterized in that, the isothermal surface of this discharge cavity is extended to and electrode tube inwall junction by the discharge cavity inwall.

6. the ceramic arc tube with isothermal structure according to claim 1; It is characterized in that; This electrode tube comprises interior pipeline section and the welding groove that is connected, and pipeline section is near discharge cavity in this, and welding groove is positioned at the end; And the interior pipeline section of the internal diameter of welding groove is big, and welding groove is realized the gas-tight seal of discharge cavity through filling scolder.

7. the ceramic arc tube with isothermal structure according to claim 6; It is characterized in that; This electrode assemblie comprises tungsten plug, cermet rod and the lead-in wire that is connected successively, and this tungsten plug stretches in the discharge cavity, and this cermet rod is positioned at pipeline section; And the external diameter of cermet rod is suitable with the internal diameter of interior pipeline section, and lead-in wire stretches out outside the electrode tube with the terminal scolder that is connected and passes in the welding groove of conducting rod.

8. the ceramic arc tube with isothermal structure according to claim 6; It is characterized in that; This electrode assemblie comprises tungsten plug, conducting rod and the contact tube that is connected successively, and this tungsten plug stretches in the discharge cavity, and this conducting rod is positioned at pipeline section; And the external diameter of conducting rod is suitable with the internal diameter of interior pipeline section, this contact tube and conducting rod be terminal is connected and pass scolder in the welding groove stretch out electrode tube outward and lead-in wire join.

9. according to claim 7 or 8 described ceramic arc tubes, it is characterized in that this cermet rod end is provided with the boss structure that cooperates the location with welding groove with isothermal structure.

10. the ceramic arc tube with isothermal structure according to claim 9 is characterized in that, this boss structure outside end face is formed with the some kinds of conical surfaces.

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