CN1311495C - Thermoswitch - Google Patents

Abstract

The present invention relates to a thermoswitch which is composed of a metal cover board of a sealed insulating fixed conductive terminal and a cylindrical metal container, and the cylindrical metal container is arranged at a welding opening end near the periphery of the cover board and is provided with a bottom. A shallow dish round plate thermal response board is arranged in the container, and a contact mechanism for switching on and switching off a fixed contact and a movable contact via the action of the thermal response board is also arranged in the container. The circular cylinder part of the metal container has the relationship of thickness t, length L and diameter D of t/L = 1/60 to 1/20, and L>= 0.5D. The heat transfer of a container bottom 3B to the thermal response board and the heat transfer of the circular cylinder part to the cover plate direction are respectively limited so as to accelerate the thermal response speed of the switch.

Description

Thermoswitch

Technical field

The present invention relates to a kind of thermoswitch that uses the thermal response plate; when for example the machine of compressor that circulates in the cold-producing medium heat-exchange system of motor vehicle or engine-driven gearing etc. is unusual; detect the temperature of superheat section, protect this machine to avoid improvement because of the thermoswitch of the overheated damage usefulness of bringing.

Background technology

In the past, as this switch, used and utilized bi-metal plate deformed to open and close the thermoswitch of electrical circuit.Thermoswitch 101 shown in Fig. 7 has discoideus metallic cover plate 102 and the container 103 of end round barrel shape is arranged, and sealing and fixing the openend of container 103 near the periphery of cover plate 102, constitutes closed container.Here, the reason that adopts closed container is to prevent that moisture etc. from entering into the inside of container, and, according to reason described later, make the composition stable for extended periods of time of the gas of enclosing internal tank.For the material of container 103,, use steel plate because welding performance is good.

Cover plate 102 is provided with through hole 102A and 102B, and these through holes metal conductive pin 104A and 104B by electrical apparatus insulation fillers such as glass 105 difference sealing and fixing.Make " コ " font near the diagram lower end of the conductive pin 104A of one side, thick conductivity fixed contact spare 106 is being fixed its illustrated upper end by methods such as welding.The lower end of conductive pin 104B is neighbouring by such as methods such as welding flexible movable contact component 107 being fixed on its stiff end 107A.Fixing movable contact 108 on the front end 107B of movable member 107, disposing in the contacted mode of contact site 106A with fixed contact spare 106.

Be provided with strike out circular shallow disc shape shaping such as bimetallic material in the bottom of container 103, make thermal response plate 109, the holding plate of being made by elastomeric material 110 is set thereon.And on holding plate 110, disposing the pressed sheets 111 that is shaped on by the thermal endurance insulating material, the front end of this pressed sheets is fixed among the hole 107C that is arranged on the above-mentioned movable contact component 107 by method such as being pressed into.

When the action of this thermoswitch 101 is described, thermal response plate 109 is outstanding bending as shown in Figure 7 downwards under the normal temperature state, rise to the temperature of qualification along with temperature, the counter-rotating of can takeofing suddenly, its bending direction preestablishes into the shape that protrude the mediad top, like this, its middle body is pushed down pressed sheets 111.Pressed sheets 111 is pushed down movable contact component 107, and the contact site 106A from fixed contact spare 106 leaves with the movable contact 108 of its front end, cuts off its circuit.

Regard to down this thermoswitch is installed in situation about installing as the used for automobile air conditioning compressor of controlling object machine, Fig. 9 of the phantom that reference is shown in Figure 8 and the enlarged drawing of this part is illustrated.The housing A of the compressor of used for automobile air conditioning here, is provided with pre-installation portion A1.This installation portion has the through hole that is arranged on the compressor discharging refrigerant path A2, and the thermoswitch 101 of installation is arranged on the position that can detect the refrigerant temperature of object to be detected rapidly.

On conductive pin 104A, the 104B of the thermoswitch of installing 101, be connected and fixed lead 112A, 112B; in the environment that uses; for anti-sealing etc. is immersed on this connecting portion; and when operation, protect it not to be subjected to external force or vibration; in thermoswitch 101, be covered with protective cap 113, insulating properties filler 114 arranged at the protective cap inner filling.

On this installation portion A1, can insert O shape ring 115 and the thermoswitch 101 made by silica gel, with the upper surface use-case of protective cap 113 as is well known circular-arc elastomeric element 116 such as snap ring keep, and by switch fixed installation hermetically portion.

This thermoswitch 101 is realized high thermal response property by thermal response plate 109 is arranged on the bottom surface of container 103.And, because problems such as installation site can make more miniaturization of thermoswitch.Yet, in above-mentioned installation example, often be exposed under the situation such as install on the used for automobile air conditioning compressor housing in the outside air, the compression case surface can siphon away heat by ambient atmos, and, since be directly installed on the heat of the thermoswitch at this place also can be by the heat conduction of ambient atmos and compressor housing dissipated heat, particularly when the low grade of extraneous gas temperature, the temperature rising rapid for cold-producing medium has the situation that can not obtain sufficient thermo-responsive.In addition, cover plate 102 is in order to keep conductive pin 104A, 104B, certain thickness must be arranged, thereby make the thermal capacitance quantitative change of cover plate 102 big, the suffered heat of container leading section is siphoned away by cover plate by the cylindrical portion of container, thereby reduced the rate of rise in temperature of thermal response plate 109, thereby the problem of the response performance deterioration of thermoswitch can occur.Particularly by making the container miniaturization, the length of container cylindrical portion shortens, and heat is walked by cover plate one side draught easily.

In addition, in order to improve response speed, as shown in figure 10, also have with the fixing effective ways of thermoswitch 101 of the conductive pin 122A front end of the inside and outside hermetic terminal that connects 122 of compressor 121.In this conductive pin, the position of the internal face more close inboard of thermoswitch by being arranged on the ratio piston compressor housing, thereby the heat that is transmitted to the compressor outside from switch can be restricted to Min., simultaneously, in as the heat transfer medium cold-producing medium, expose the integral body of switch, thereby can improve thermo-responsive.Use oil plant to substitute test if replace thermal medium, action needed time that finishes has descended only about half ofly, uses in reality and also to have confirmed same effect.Yet this method is owing to must allow the width of refrigerant passage, and is wide to the degree that is enough to accommodate thermoswitch, thereby can occur allowing the housing of compressor maximize, and the number change of parts is many, the problem that price uprises.And, foregoing cover plate thermal capacity height also can appear, and the low problem of the rate of rise in temperature of thermal response plate.For this reason, need a kind ofly can not allow compressor housing maximize, and do not increase number of components etc., can improve the thermoswitch of thermo-responsive with comparing in the past.

Summary of the invention

For this reason, in thermoswitch of the present invention, have discoideus metallic cover plate, on this cover plate, running through two through holes, in these holes, keeping the 1st and the 2nd terminal airtightly respectively by the electric insulation filler, it also has a metal container, constitute by near the cylindrical portion that has openend the periphery that is sealed in above-mentioned cover plate and the bottom surface sections of shallow disc shape, this container constitutes airtight container by openend is welded on the above-mentioned cover plate, accommodating the counter-rotating action of under predetermined working temperature, takeofing fast along the inner bottom surface of this container, and the discoideus thermal response plate that the shallow disc shape that the counter-rotating of takeofing fast under recovery temperature is replied is shaped, dispose flexible holding plate on the opposite of this thermal response plate, on above-mentioned the 1st terminal, welding fixed contact spare, and on the 2nd terminal, welding movable contact component, be provided with on this movable contact component and the opposed pressed sheets of above-mentioned thermal response plate, it is characterized in that, its thickness setting of metal container is 1/60 to 1/20 of the diameter of cylindrical portion, and the length setting of cylindrical portion is at more than 0.5 times of diameter, thereby respectively the heat transmission of the bottom surface thermotropism response panel of restricted passage container and from the bottom surface side of container by the heat transmission of cylindrical portion, to adjust the rate of rise in temperature of thermal response plate towards the direction of cover plate.Such structure makes the heat of the metallic container bottoms of thermoswitch be difficult to housing transmission from the cylindrical portion of container towards compressor, in situation that refrigerant temperature rises rapidly etc., the heat hot response panel effectively by suppressing scattering and disappearing of heat, thus the response speed of thermoswitch can be improved.

Thermoswitch of the present invention, it has discoideus metallic cover plate; On this cover plate, running through two through holes, in these holes, keeping the 1st and the 2nd terminal airtightly respectively by the electric insulation filler; It also has a metal container, is made of near the cylindrical portion that has openend the periphery that is sealed in above-mentioned cover plate and the bottom surface sections of shallow disc shape, and this container constitutes airtight container by openend is welded on the above-mentioned cover plate; Accommodating under the working temperature of being scheduled to, takeofing fast counter-rotating action along the inner bottom surface of this container, and at the discoideus thermal response plate that is lower than the shallow disc shape shaping that takeofing fast under the recovery temperature of described working temperature reverses replys; Dispose flexible holding plate on the opposite of this thermal response plate; On above-mentioned the 1st terminal, weld fixed contact spare respectively, on the 2nd terminal, weld movable contact component; Be provided with on this movable contact component and the opposed pressed sheets of above-mentioned thermal response plate; It is characterized in that: by being that the metal below 1/2nd of iron constitutes with metal container pyroconductivity, thereby when the heating container part, suppress heat transferred speed, to improve the rate of rise in temperature of container bottoms to the cover plate side.

In addition, another feature of the present invention is, metal container by pyroconductivity at least at the metal below 1/2nd of iron, formations such as fe-cr alloy, Fe-Ni alloy, stainless steel for example.By this formation, even the switch of the metallic container of thermoswitch is basic identical with goods in the past, the heat of container bottoms also is difficult to the housing transmission from the cylindrical portion of container towards compressor, and, by the relation that the thickness of container cylindrical portion and length setting are become to be scheduled to, band can strengthen heat with container bottoms and be delivered to effect on the thermal response plate rapidly, thereby can improve the response speed of thermoswitch.In addition, by coming like this to select container, even switch itself big or small identical or more greatly, owing to can improve thermo-responsive significantly, thereby almost there is no need to change installation site in the past, the housing of compressor is maximized.

In addition, another feature of the present invention is, encloses the sealing gas of the helium that contains 50%-95% to be higher than atmospheric pressure in closed container, thereby rapidly the heat of container is delivered on the thermal response plate when temperature rises rapidly.In addition, by allowing the gas of enclosing be in more than the atmospheric pressure, and make extraneous gas be not easy to be immersed in the container, thereby can make the composition long-term stability of enclosing gas.

The present invention also has a feature to be, near the circumference of cover plate stage portion is set, be with container open end nearby inner peripheral surface and the outer rim of the stage portion of cover plate roughly assemble in contact.In the present invention,, can prevent also that by this stage portion it from entering into internal tank, simultaneously, when assembling, can also accurately and easily carry out the contraposition of cover plate and container even produce so-called splash when the welding of cover plate and container by such structure.

Another feature of the present invention is to fix each lead by welding on the 1st and the 2nd terminal.Compare with using the soldering immobile phase, can in higher ambient temperature, use.

Description of drawings

Fig. 1 is the cutaway view of an embodiment of thermoswitch of the present invention;

Fig. 2 is the cutaway view of the thermoswitch operate condition of presentation graphs 1;

Fig. 3 is the cutaway view along A-A line among Fig. 1;

Fig. 4 is the phantom that the thermoswitch of presentation graphs 1 is installed in the state on the controlling object machine;

Fig. 5 is the partial enlarged drawing of Fig. 4;

Fig. 6 is the vertical view of the holding plate that uses in the thermoswitch of Fig. 1;

Fig. 7 is the cutaway view of an example of thermoswitch in the past;

Fig. 8 is the partial sectional view that the thermoswitch of presentation graphs 7 is installed in the state on the controlling object machine;

Fig. 9 is the partial enlarged drawing of Fig. 8;

Figure 10 represents that in the past thermoswitch is installed in the partial sectional view of the installment state on the controlling object machine.

Among the figure: the 1st, thermoswitch, the 2nd, cover plate, 2A are stage portion, 2B, 2C are through holes; the 3rd, container, 3C are cylindrical portion, and 4A, 4B are conductive pins, the 5th, and filler; the 6th, fixed contact spare, 6A are fixed contact portions, the 7th, and movable contact component; the 8th, movable contact, the 9th, thermal response plate, the 10th, holding plate; the 11st, compression plate, 12A, 12B are leads, the 13rd, protective cap; the 14th, filler, the 15th, O shape ring, the 16th, elastomeric element.

Embodiment

Embodiment

Below with reference to Fig. 1-Fig. 5 this thermoswitch is described.Fig. 1 is the cutaway view of an embodiment of expression thermoswitch of the present invention, Fig. 2 is the cutaway view of its operate condition of expression, Fig. 3 is the cross-sectional view of Fig. 1, to be expression be installed in phantom as the state on the used for automobile air conditioning compressor of an example of controlling object machine with this thermoswitch to Fig. 4, and Fig. 5 is its part enlarged drawing.

This thermoswitch 1 has discoideus metallic cover plate 2 and round-ended cylinder shape metallic container 3 is arranged, and is fixed by process seals such as annular projection weldings and constitutes closed container by being arranged at lip portions 3A on container 3 openends on the circumference of cover plate 2.Container 3 is by metallic plate is had a round-ended cylinder shape through what pull and stretch such as pressure processing formed, and in the present embodiment, the length L of the cylindrical portion 3C of container 3 is by setting the length than in the past, thereby alleviates thermal gradient between the cylindrical portion two ends.In addition, the bottom surface 3B of container has formed the sphere shape shallow disc shape shown in Fig. 1 etc. in order to have high withstand voltage properties.

In the present invention by will be, and obtain relation with respect to the thermoswitch container pyroconductivity of operate time, container cylindrical portion length and thickness through the container transfer of heat of thermoswitch as main aspect.That is,, be difficult to transfer to the outside just result from the heat of container bottoms if the container pyroconductivity of thermoswitch is low, and if the thickness of container cylindrical portion is thin because sectional area is little, heat still is difficult to shift.In the present embodiment, under the constant situation of the thickness t of container, do its length longer, thereby relax the thermal gradient at container cylindrical portion two ends, suppress heat and shift from the cylindrical portion bottom surface than in the past.

Cover plate 2 is provided with the 1st and the 2nd through hole 2B and 2C, fixes metallic conductive pin 4A and 4B as the 1st and the 2nd terminal of thermoswitch on this through hole respectively, with electrical insulating property fillers such as glass 5 difference sealing and fixing.To become the certain thickness that has of " コ " font to have conductivity fixed contact spare 6 to be fixed on illustrated upper end near the diagram lower end of the conductive pin 4A of a side with methods such as welding.The leading section of this fixed contact spare 6 is provided with the 6A of fixed contact portion that silver alloy etc. constitutes.In addition, near the lower end of guide finger 4B, have movable contact component 7 usefulness that abundant flexible copper alloy constitutes and be fixed on its stiff end 7A such as methods such as welding by beryllium copper etc.Fixing the movable contact 8 of silver alloy etc. on the front end 7B of movable contact component 7, be arranged to the contacted state of fixed contact 6A with fixed contact spare 6.

In this case, fixed contact spare 6 and movable contact component 7 weld by same direction as shown in Figure 3 with respect to conductive pin 4A that is welded on each weld part 6B and 7A and 4B respectively, in addition, the welding position is to make the position that is in the conductive pin that does not hinder the other side as the electrode E1-E4 of weld jig on the extended line W1 of the line of the center of as shown in the figure each conductive pin and pad and the W2, and two conductive pins are in the position that can not interfere each contact component welding.Like this, be easy under the situation automation of also welding easily at installation exercise.And weld jig or welding electrode also can be made the shape that can not be in the way to compression aspect, thereby improve the life-span, alleviate the burden of maintenance operation.Narrow down between the conductive pin by allowing, also can also make small-sized thermoswitch.

The bottom 3B of container 3 goes up and strikes out circle by the material with the bimetallic class, under predetermined temperature, can make its bending direction counter-rotating and answer, is arranged to the thermal response plate 9 that shallow disc shape is shaped, and the holding plate 10 that elastomeric material is made is set thereon.Configuration is by the pressed sheets of making such as the thermal endurance insulating material of pottery 11 above holding plate 10 again, and the front end 11A of this pressed sheets is fixed among the through hole 7C that passes above-mentioned movable member 7 by method such as being pressed into.

This holding plate 10 by becoming a plurality of 10A of foot of radial extension from the center, has 4 10A of foot as shown in Figure 6 in the present embodiment, becomes umbrella shape with predetermined angular bend respectively, forms the elastic plate of being made by thin phosphor bronze or beryllium copper etc.Holding plate 10 is pressed to the direction of bottom 3B with thermal response plate 9 all the time with the power that its action is not had a materially affect degree, makes it to be in contact with one another and locatees.In addition, the central authorities of holding plate 10 run through and are provided with through hole 10B, and the lower end 11B of pressed sheets 11 is to insert among this through hole 10B from its slightly outstanding mode.Like this, can easily carry out the location of pressed sheets 11, simultaneously, can prevent that thermal response plate 9 from reversing the action of replying repeatedly and the aftermentioned distortion of the holding plate 10 that causes.And holding plate 10 is owing to be that thin plate and the 10A of foot are very thin, and only the front end by foot contacts with thermal response plate 9, and therefore, the heat of thermal response plate 9 is difficult to be delivered on the pressed sheets 11 by holding plate, thereby can suppress the heat dissipation by conductive pin.

The action of this thermoswitch example in the past with above-mentioned basically is identical.Promptly under the normal temperature state, thermal response plate 9 is the case of bending that protrudes shown in Figure 1 downwards, when arriving predetermined the 1st temperature (working temperature) along with the temperature rising, the jerk counter-rotating, bending direction is become the shape of mediad top protrusion as shown in Figure 2, its middle body contacts with the pressed sheets lower end 11B that inserts holding plate 10 central authorities, with pressed sheets 11 jack-up.Pressed sheets 11 boosts movable contact component 7 again, and the movable contact 8 of its front end leaves from the fixed contact 6A of fixed contact spare 6, thereby cuts off circuit.In case the temperature of tablet 9 drops to predetermined the 2nd temperature (recovery temperature) from the condition of high temperature, thermal response plate 9 is replied its bending direction, and travelling contact 8 is contacted with the 6A of fixed contact portion again, makes the circuit between conductive pin 4A, the 4B recover conducting.Insert partially because the lower end 11B of pressed sheets 11 is therefrom outstanding in the through hole 10B of holding plate 10, in above-mentioned protection action, when thermal response plate 9 protrudes the counter-rotating action above carrying out, directly conflict with the lower end 11B of pressed sheets 11.Consequently, holding plate 10 is clipped in it between pressed sheets 11 by thermal response plate 9 and does not have directly to come and go to kowtow and hit, can not occur because of this repeatedly kowtow the problem that makes holding plate 10 distortion or extend of hitting.

Below to thermoswitch 1 is installed in as the situation on the used for automobile air conditioning compressor of one of controlling object machine with reference to the phantom of Fig. 4 with and Fig. 5 of part enlarged drawing be illustrated.The housing A of this used for automobile air conditioning compressor is identical with above-mentioned embodiment in the past, is preset with the installation portion A1 of thermoswitch.This installation portion has the through hole on the discharging refrigerant path A2 that is arranged on compressor housing A, the thermoswitch 1 that inserts container 3 and install is in the position that can detect the refrigerant temperature variation rapidly owing in the discharging refrigerant that is directly exposed to as detected material.

Thermoswitch 1 is fastened on lead 12A (12B) on its conductive pin 4A (4B) by welding; and in practical environment; for anti-sealing etc. is immersed in this coupling part; and it is protected be subjected to external force and vibration when preventing work; on thermoswitch 1, be coated with protective cap 13, insulating properties filler 14 arranged at the inner filling of protective cap.

The O shape ring 15 that the thermoswitch of this structure is made with silica gel etc. is inserted into the installation portion A1 from the compressor outside, between the outer wall of the inwall by sealing up installation portion A1 with this O shape ring 15 and the container 3 of thermoswitch and the flange portion of cover plate 2, thereby through hole and this installation portion A1 are sealed.In addition, with the upper surface of protective cap 13 by well-known circular-arc elastomeric element 16 to maintain by snap ring and switch can't be fixed with coming off.This thermoswitch 1 since the outer wall inner surface that remains fixed in ratio piston compressor housing A also will be in the outer part the position, thereby can fix in the bubble-tight mode of guaranteeing the installation portion in O shape ring and the elastomeric element effectively.Here, the container outer wall of thermoswitch 1 is difficult for dissipated heat, the inner surface of installation portion A1, i.e. and not directly contact of the outer wall of housing A, the metal part that has cover plate 2 does not contact with the housing A of compressor.This thermoswitch 1 and comparing in the past, because container is elongated, the Lower Half of switch container is exposed in the circulation path of discharging refrigerant, can accept effectively from the heat as the cold-producing medium of detected material.

In the present embodiment, by cylindrical portion 3C lengthening with thermoswitch container 3, though can suppress to give out heat from container bottoms, and in the occasion that the heat translational speed will be had more effective inhibition, not only cylindrical portion to be done length, but also must do the thickness t of container 3 thin.Yet in case the length L of cylindrical portion is done length, the switch installation site just can become greatly, owing to need the space, thus can make the controlling object machine, be that the housing of compressor has to maximize in an embodiment.And, thin to the requirement of inductive switch container speed as if the thickness t of container is done, also can produce the problem of the resistance to pressure reduction of switch container.

In the present invention, be the metal below 1/2nd of iron with the metallic container by pyroconductivity, preferably pyroconductivity constitutes at 1/3rd following metals of iron, and thus, the length or the thickness of container are constant, also can suppress the transmission speed of heat.And, by the relation that the diameter of cylindrical container and thickness setting are become to be scheduled to, even at for example thermal conductivity ratio is under 1/2nd taller situations of iron, the heat transfer speed that also can suppress container, in addition, in the littler metal of thermal conductivity ratio iron, its effect can increase, thereby can improve the response speed for thermoswitch.For this container 3, for example used selected suitable product in ferroalloy or the nickel alloy etc.In the present embodiment, used in the container 3 and corrosion resistant plate (SUS304) carried out pressure processing etc. is rammed to have bottomless drum shape cylindric, its pyroconductivity is about 1/5th of iron at normal temperatures.It is about 1/4th of the cold-rolled steel sheet that in the past used.

As this container, using under the high situation of stainless steel constant resistance value, the difference of cover plate and condenser resistance value is very big, when welding, the part of weld metal can be dispersed away, thereby the possibility that produces splash is arranged, and in a single day splash enters in the container, can produce the adverse effect to the action of each several part or insulating properties etc.Here, stage portion 2A is set near the circumferential part of cover plate 2 of the present invention, container 3 forms near the inner peripheral surface its openend the form of roughly joining with the stage portion 2A outer rim of cover plate 2.Like this, when cover plate 2 welds with container 3,, can prevent to enter into internal tank owing to stage portion 2A even produce splash.And, by such structure, the contraposition operation of cover plate and container in the time of can also easily assembling.

According to thermoswitch of the present invention, having low value more for the pyroconductivity of container 3 by using more in the past than the cold-rolled steel sheet that uses, is the metal below 1/2nd of iron, for example stainless steel etc., compare with thermoswitch in the past, can improve thermal response speed.Be installed at the thermoswitch that will use the good container of above-mentioned heat conductivity in the past under the situation on the housing of compressor, the heat of the container bottom 3B of thermoswitch passes the thermotropism response panel by container, simultaneously, cylindrical portion by the switch container shifts to the compressible engine housing of the low cover plate of humidity, has in fact suppressed the rate of rise in temperature of thermal response plate.

When on compressor, installing in the past, the metal part of cover plate etc. is not directly to contact with the metallic housing of compressor, because also transfer of heat such as sealing resin on the switch, sharply rising to wait in refrigerant temperature particularly requires under the situation of rapid response speed, can not obtain the effect of being satisfied with.In addition, the metallic cover plate that constitutes airtight container is compared with container and is used thick metallic plate, thereby has bigger thermal capacity, passes to heat on the container owing to the heating to this cover plate becomes the major reason of delay to the heating of thermal response plate.In addition, in order to improve compression resistance the container bottoms of switch is made shallow disc shape, increase the distance of thermal response plate and container bottoms slightly, make and penetrate heat from the width of cloth of container bottoms and be difficult to arrive on the thermal response plate, this also is the factor that needs are considered.

In addition, above-mentioned in the past example or thermoswitch of the present invention in use under the situation of closed type container, be that the ratio of will enclose helium in the inner sealing gas improves in the past, heat from container is passed on the thermal response plate easily, the result can make the response time shorten, but only this is not talkative very abundant.Though this can not used metallic plate and adopts the low lid made of resin plate of pyroconductivity, peristome is sealed by fillers such as resins, but this structure is difficult to guarantee the effective seal performance, even enclose predetermined gas, through the long time, then stably young bird is held its composition, therefore can not expect that it has the raising of long-term heat conductivity.

Given this, be conceived to move, carried out various experiments, must allow the operate time of judging thermoswitch the relation of the diameter D of container and thickness t suitable from the heat of the container bottom of thermoswitch.That is, for the vary in diameter of switch container cylindrical portion, the area of the thermal response plate that its inside is included in changes with the ratio of the quadratic power value of above-mentioned diameter.Like this, under the certain situation of the thickness t of container cylindrical portion 3C,,, make that the heat through above-mentioned cylindrical portion loses easily just can increase relatively to the cylindrical portion outer wall sectional area of the unit are of thermal response plate if the diameter D of container cylindrical portion is done little.In addition, under the situation with the enlarged diameter of container cylindrical portion, though opposite, heat is difficult to scatter and disappear, if make the thickness attenuation with respect to diameter, the problem that said withstand voltage properties reduces will occur.

In the experiment of carrying out considering these problems, the thickness t that has obtained cylindrical portion is the conclusion that 1/60-1/20 relatively is fit to respect to its diameter D.For example, if the thickness of container cylindrical portion is in more than 1/20 of diameter, the heat that is delivered to the container front end will be become many by cylindrical portion by the heat that housing of the cover plate of switch or controlling object machine etc. is seized, thereby has reduced the response time of thermoswitch, makes response performance insufficient.In addition, under this thickness is situation below 1/60, then voltage endurance capability can be reduced, under situation about it being arranged in the compressed refrigerant, the possibility of container deformation can be occurred making owing to the pressure of cold-producing medium.To this,, just can make the response of thermoswitch and withstand voltage properties satisfactory to both parties by the wall thickness of cylindrical portion being arranged to the 1/60-1/20 of its diameter.

In addition, if the diameter of container is certain, just derive out with the constant of almost fixed by the pyroconductivity of container and the length and the thickness of container cylindrical portion the operate time of thermoswitch.Promptly, if the pyroconductivity of thermoswitch container is low, the heat that container bottoms applied just is difficult to shift to the outside, if and the thickness of container cylindrical portion is thin, because the outer wall sectional area of cylindrical portion diminishes, also can make heat be difficult to transmit, and the length of cylindrical portion is long, owing to thermal gradient is slowed down, also is difficult to make transfer of heat.Consider the experimental result of these problems, and the result of comprehensive discussion, the container pyroconductivity of thermoswitch and shape and operate time are derived by following formula, and index T judges roughly relation by operate time.

(formula 1)

Operate time index: $T=A\·\mathrm{\λ}\left(\frac{t}{L}\right)+\frac{B\·t}{\sqrt{\mathrm{\λ}}}$

(wherein, λ is a pyroconductivity, and t is a container cylindrical portion thickness, and L is a container cylindrical portion length, and A and B are constants)

If this time index T is roughly proportional with the operate time that substitutes in the attribute testing of thermoswitch in certain condition and range.Its value and comparing in the past can dope operate time from container pyroconductivity and shape at an easy rate.For example in the thermoswitch of present embodiment and above-mentioned example in the past, derived the empirical formula of described relation.

(formula 2)

Predict operate time: $\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="C20041003840200201.png,C20041003840200202.png"\; state="\{\{state\}\}">T</figure-callout>}1=32000\mathrm{\&lambda;}\left(\frac{t}{L}\right)+\frac{2.2t}{\sqrt{\mathrm{\&lambda;}}}$

(wherein, λ is a pyroconductivity, and t is a container cylindrical portion thickness, and L is a container cylindrical portion length, but 0.1≤t≤0.6[mm], 4≤L≤20[mm] and, 0.005≤λ≤0.1[W/ (mmK)])

Below the attribute testing that substitutes that derives this prediction T1 operate time is described, the diameter D of its container cylindrical portion of the thermoswitch of testing is 12.8mm, and the diameter of the thermal response plate of accommodating is 12.0mm.And cover plate has used at diameter and has been 17mm, and thickness is that the cold-rolled steel sheet (SPCE) of 1.6mm is gone up the fixedly form of conductive pin, encloses the gas of internal tank, and nitrogen is 25% for 75%-helium, and enclosing gas pressure is 130kPa without exception.In addition, be protective cap shown in Figure 4 13 and lead to be installed under the state on the thermoswitch carry out during test.Test method as previously mentioned, be with 155 ℃ down the thermoswitch of action be immersed in 180 ℃ the silicone oil, not with the contacted situation of other parts such as cover plate under, container part is immersed in 180 ℃ the silicone oil, determine time up to switch motion.This prediction operate time T1 each the value substitution condition and range in, the thickness t that is container is 0.1-0.6mm, the length L of container cylindrical portion is 4-20mm, and under the situation in the scope that pyroconductivity is defined in from iron to the stainless steel degree, form consistent with the operate time that substitutes in the test of thermoswitch.

For example, under the container (pyroconductivity is 0.015W/ (mmK)) of the stainless steel SUS304 of embodiment system, the thickness t of container is 0.3mm, and the length L of the cylindrical portion of container is under the situation of 12.1mm, and T1 is 14.99, with 15.2 seconds basically identicals of actual measurement mean value.The result of the test of various samples is as shown in table 1 with the relation of prediction operate time.And switch container cylindrical portion diameter is 12.8mm.

(table 1)

	Embodiment 1	Embodiment 2	Embodiment 3	Embodiment 4	Embodiment 5	Routine in the past
							SUS30 4	SUS30 4	?SUS30 ?4	Steel plate (SPCE)	Steel plate (SPCE)	Steel plate (SPCE)
	λ	0.015	0.015	?0.015	0.062	0.062							0.062
L							6.8	12.1	?12.1	6.8	12.1	5.5
	t	0.3	0.3	?0.4	0.3	0.3							0.3
Prediction (the value of empirical formula: T1) operate time							26.56	14.99	?23.05	90.18	51.84	110.9
	Operate time (measured value is average)	25.9	15.2	?23.4	89.4	51.8							115.7

The operate time that this prediction T1 operate time and various sample substitute in the attribute testing is unanimous on the whole.Is more than 0.5 times of diameter D from this experiment value and measured value by container cylindrical portion length L is made, and compares with example in the past, has improved 20% operate time as can be seen.Specifically, be 6.8mm for length L, diameter D is the situation of 12.8mm, and the actual measurement mean value of operate time is switching in 90 seconds, and as shown in Figure 7, length L was the example in the past of 5.5mm, to then remaining 115 seconds of action.The response performance of thermoswitch requires to be preferably in below 60 seconds below 90 seconds in this experiment.

Specifically, prediction T1 operate time, as shown in Figure 7, if container (pyroconductivity is 0.062W/ (mmk)) in the past with cold-rolled steel sheet system, the thickness t of container is 0.3mm, and the length L of cylindrical portion is 5.5mm, if be worth below 1/3rd corresponding to it, just can obtain identical experimentally or be higher than its performance, thereby can obtain more performance with situation in the cold-producing medium that thermoswitch integral body is exposed to.Use the embodiment 1-3 of container of stainless steel as shown in table 1, satisfy this condition respectively, test on the controlling object machine in actual installation and also confirmed this result.In addition, use among the embodiment 4 and 5 of cold-rolled steel sheet and can not obtain the high effect shown in the embodiment 1-3,, also can compare the time significantly under reach with embodiment in the past by cylindrical portion diameter and the length and the thickness of selected container.

From aforementioned calculation value and experimental result as can be seen, under container valve and identical in the past situation, (λ's=0.075W/mmk) is about below 1/2nd, is the about below 2/3rds of the steel plate that in the past used, just can access satisfied responsiveness to make pyroconductivity and be iron.In addition, do the length L of container cylindrical portion than in the past length, make to allow and move the thermoswitch that is delayed towards the cover plate heat, also can the shortening heat response operate time.For example, from above-mentioned empirical formula as can be seen, under the identical situation of container thickness and pyroconductivity,, the length that surpasses twice at least in the past must be arranged in order to obtain and the identical performance of situation that switch integral body is exposed in the cold-producing medium.

Be particularly suitable for obtaining high precision under the situation that diameter in thermoswitch container cylindrical portion is 8-15mm by the correlation that this formula drew.Formula 2 then meets the concrete experimental result of using the thermoswitch of shape among the embodiment, determine the constant A and the B of formula 1, for example, under the situation of change thermoswitch container diameter etc., by setting this constant A and B for the new condition that meets, thereby can draw the numerical value close with the actual act time.

The thermal response property of thermoswitch is improved by enclosing the good sealing gas of heat conductivity at the switch internal tank.And the gas of enclosing in the switch container causes convection current in container when being delivered on the thermal response plate with heat with the switch container, can cause that also this heat on the cover board scatters and disappears.Yet, in the construction of switch of embodiment, because the thermal response plate is near the bottom surface of container, can think and more effectively carry out than the heat of transferring to because of convection current on the cover plate to the heat part on the thermal response plate by the gas transfer of enclosing, detecting under the situation that temperature very sharply rises, by the gas of enclosing is adjusted to the heat conduction good state, the ratio that is about to enclose the helium in the gas improves or the pressure that will enclose gas uprises etc., all is effectively approach.

Thermoswitch is by enclosing predetermined gas in closed container, keep its long-term stability, for the gas of being enclosed is carried out airtight test and encloses helium with dry air or nitrogen etc., helium is compared with dry air or nitrogen, because heat conductivity height, improve the heat conductivity of enclosing gas by the ratio that in the gas of this inclosure, increases helium, thereby can on the thermal response plate, import heat as early as possible into from container.

Helium is compared with nitrogen or air, its pyroconductivity is high 6 times, when temperature sharply rises, heat from container is easy to be delivered on the thermal response plate, for example in container, use in 155 ℃ of thermoswitches that move down of steel plate, enclosing helium in the gas and be 25% and 50% or even 75% switch determines the switch container part by experiment respectively and is immersed in operate time in 180 ℃ the oil respectively, compare, in switch with 50% helium, with with 25% compare, its reaction time has improved 5%, and with the switch of 75% helium, with with 25% compare, its response time has improved about 10%-15%.

Therefore, by helium content is increased to more than 50%, breathing hard as the compressor refrigerant of heat catalysis, temperature rises the rate of rise in temperature that can do sth. in advance the thermal response plate in the time.Preferably adopt the helium more than 75%.In addition, if helium, will reduce contact proof voltage power between contact when open near 100%, and under the situation for the cell voltage that uses automobile etc., problem can not take place actually.Yet in the inspection technology during fabrication, undertaken by voltage determination between contact under the situation of distance inspection between contact, voltage range narrows down and is difficult to judge operation.Here, its upper limit is preferably in 95%.In the thermoswitch of Fig. 1, during with the comparing of container and stainless steel, with enclose gas be 25% helium-75% nitrogen with the comparing of 75% helium-25% nitrogen, substitute in the experiment with oily characteristic of carrying out, shorten 20% or more than the former the latter's operate time.At this, become big with using comparing of steel plate, its rate of change in the container, above-mentioned stainless pyroconductivity is low, and the bottom surface temperature of container is risen early, and this heat is delivered on the thermal response plate effectively, and change gas can more effectively be worked.

Below in the container of thermoswitch, using stainless situation to be illustrated in the foregoing description, in addition, selecting pyroconductivities such as Fe-Ni alloy or fe-cr alloy, nickel-chromium alloy, nickel-copper alloy is the metal below 1/2nd of iron, preferably pyroconductivity is the metal below 1/3rd of iron, can obtain same effect.

In thermoswitch in the past, lead and switch use soldering to connect into conductivity and fix, yet, because the melt temperature of soldering is lower, for example, surpassing under the condition of 200 ℃ of temperature in short-term, the danger of wire dropping can occur, thereby this thermoswitch can not use.Here, in the present invention as shown in Figure 5, lead 12A, 12B are fixed on conductive pin 4A, the 4B of thermoswitch 1 with direct welding such as resistance welding machines.With in the past the sort of with lead with soldering immobile phase ratio, even can guarantee effectively also that under the situation of high temperature lead is connected with the electrical equipment of switch, thereby can under than higher in the past temperature, make switch work.

As mentioned above, pass through diameter, thickness and the length setting of the metallic container cylindrical portion of thermoswitch are become predetermined relation according to the present invention, thereby limit respectively from the bottom surface of container towards the heat transferred of thermal response plate, and by the heat transferred of cylindrical portion to the cover plate direction, consequently can improve the rate of rise in temperature of thermal response plate, thereby improve the response speed of thermoswitch.

In addition, the steel plate that in the past used by the use thermal conductivity ratio is low, preferably use the metallic container 1/3rd below of pyroconductivity as iron, stainless steel for example, can suppress by container to outside dispersed heat, thereby the heat of cold-producing medium effectively and promptly can be delivered on the thermal response plate that is contained in internal tank.

In addition, be the sealing of 50%-95% ratio by the gas that will enclose in the container in the content of helium, when the medium temp of the heat of the refrigerant gas of compressor particularly etc. sharply rises, the heat of container promptly can be delivered on the thermal response plate.

In addition, according to the present invention, near the circumferential part of cover plate, stage portion is set, by on the outer rim of this stage portion, engaging the inner peripheral surface of container, even thereby when container and cover plate weld, produce splash, can prevent also that by this stage portion it from entering into the inside of container, simultaneously, the contraposition operation of cover plate and container in the time of can also assembling at an easy rate by this structure.

In addition, the present invention is fixed on the 1st and the 2nd terminal by lead is welded respectively, and the soldering immobile phase ratio with in the past can obtain the thermoswitch that uses in high temperature environment.

Claims (6)

1. thermoswitch, it has discoideus metallic cover plate;

On this cover plate, running through two through holes, in these holes, keeping the 1st and the 2nd terminal airtightly respectively by the electric insulation filler;

It also has a metal container, is made of near the cylindrical portion that has openend the periphery that is sealed in above-mentioned cover plate and the bottom surface sections of shallow disc shape, and this container constitutes airtight container by openend is welded on the above-mentioned cover plate;

Accommodating under the working temperature of being scheduled to, takeofing fast counter-rotating action along the inner bottom surface of this container, and at the discoideus thermal response plate that is lower than the shallow disc shape shaping that takeofing fast under the recovery temperature of described working temperature reverses replys;

Dispose flexible holding plate on the opposite of this thermal response plate;

On above-mentioned the 1st terminal, weld fixed contact spare respectively, on the 2nd terminal, weld movable contact component;

Be provided with on this movable contact component and the opposed pressed sheets of above-mentioned thermal response plate;

It is characterized in that:

By being that the metal below 1/2nd of iron constitutes with metal container pyroconductivity, thereby when the heating container part, suppress heat transferred speed, to improve the rate of rise in temperature of container bottoms to the cover plate side.

2. thermoswitch as claimed in claim 1 is characterized in that: described fixed contact spare and described movable contact component are that the center that links this terminal is parallel with the extended line of this welding position to each welding position of described each terminal.

3. thermoswitch as claimed in claim 1 is characterized in that: described metal container is that any alloy constitutes in fe-cr alloy, Fe-Ni alloy, Fe-Ni-Cr-alloy or the nickel-chromium alloy.

4. thermoswitch as claimed in claim 1 is characterized in that: enclose the sealing gas of the helium that contains 50%-95% to be higher than atmospheric pressure in described container.

5. thermoswitch as claimed in claim 1 is characterized in that: near the circumference of described cover plate stage portion is set, allows the openend inner peripheral surface nearby of described container roughly contact with the outer rim of the described stage portion of cover plate.

6. thermoswitch as claimed in claim 1 is characterized in that: fix each lead by welding on the described the 1st and the 2nd terminal.

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