CN101126671A - Method and instrument for carrying out leakage test for closed container - Google Patents
Method and instrument for carrying out leakage test for closed container Download PDFInfo
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- CN101126671A CN101126671A CNA2007101419309A CN200710141930A CN101126671A CN 101126671 A CN101126671 A CN 101126671A CN A2007101419309 A CNA2007101419309 A CN A2007101419309A CN 200710141930 A CN200710141930 A CN 200710141930A CN 101126671 A CN101126671 A CN 101126671A
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Abstract
The utility model provides a method and the instrument for doing leakage test on a closed vessel with at least one flexible wall region, which is characterized in that the eccentric compression part is moved to the flexible wall region to exert predetermined pressure on the region and the counterforce is monitored with time going.
Description
This application is that international filing date is dividing an application of September 26, Chinese application number in 2000 are 00819910.8, international application no is PCT/CH00/00526 application.
Technical field
The present invention relates to method, and relate to leak test instrument, do not relate to this container whether product is housed leak testing closed containers with this flexible wall district to leak testing closed containers with at least one flexible wall district.
Background technology
A kind of technical method of known test closed container is that the container that will test is placed in the test chamber, then test chamber is sealed, then the surrounding space of the inner test container of wanting of test chamber is found time, and after vacuum tightness reaches predeterminated level, estimate in this container surrounding space pressure over time.Though the degree of accuracy of this technical method is very high, it is careful to reach the essential extreme care of this pinpoint accuracy.The volume of test chamber and shape thereof must meet the outer shape of the test container of wanting just.Will make on the one hand volume reduce to minimum correspondingly to shorten the time that vacuumizes, the degree that reduces of volume has determined the accuracy of detection that can reach to a great extent on the other hand.When changing the pressure of container surrounding space as the seepage test index, because seepage makes the affected volume of pressure more little, testing precision is high more.
In addition, degree of accuracy is gone back the vacuum tightness influence of receptor surrounding space to a great extent, therefore, in order to reach pinpoint accuracy, must use comparatively expensive vacuum pump, if make vacuum drop to the level of having only turbine vacuum pump to reach, even also to use multistage vacuum pump.
Summary of the invention
The purpose of this invention is to provide a kind of aforesaid method and instrument, it can remedy existingly carries out shortcoming in the leak test technology by pressure monitoring.This purpose realizes that by aforesaid leak test method it comprises step: bias piece is relatively moved towards the flexible wall district of container and arrive in the flexible wall district of container, stop to move and monitor the biasing force on the described container.The biasing force of being monitored is taken a sample and obtain the first power measuring-signal at very first time point, and take a sample and obtain the second power measuring-signal at least one second time point thereafter.The difference signal that will produce according to these two measuring-signals is as the seepage indicator signal.
Therefore, principle of the present invention is, when container that bias voltage will be tested, can make this container compression or expands, and expands or the biasing force of compression reaction force will act on the outside surface of chamber wall as container.This reacting force is easy to monitoring.Stop then if make this bias voltage reach predetermined level,, will monitor the constant reacting force of closed container according to the bias level that is reached.If container has seepage, between the surrounding space of container and inside thereof Medium Exchange will take place so, make the reacting force that is monitored As time goes on reduce.
Therefore, the degree of accuracy of this technology basically with the volume-independent of when test container surrounding space, and mainly be to detect the surface by bias voltage degree and the counteractive power of bias voltage container to be determined.
In the preferred embodiment of the inventive method, bias voltage reaches predetermined biasing force.
After reaching this predetermined biasing force, suggestion was waited for the regular hour earlier, and can be produced difference signal according to the first and second power measuring-signals before the first and second power measuring-signals are taken a sample respectively.So in during this period of time, it is stable that the shape of bias voltage container can keep.In the embodiment of practical operation, the bias voltage of container is to control according to the variation of generation difference signal in the test, thereby can make described difference signal remain predetermined value, and the action of bias piece is indicated as a kind of seepage.So, set up negative feedback loop, wherein bias piece controllably reacts on the variation that the power of being monitored produces because of seepage, make basically can be not strong variation take place because bias piece can keep constant reacting force by suitable action.
In preferred embodiment, the bias voltage container is by realizing on the chamber wall that outer surface is relatively moved, and pressure reduction realizes but form between internal tank and surrounding space thereof.So in this preferred embodiment, pressure reduction is set up by the evacuated vellel surrounding space.So the flexible wall district of container has bandy trend, and if this outwardly-bent static surface by external container stops, container will be used on these surfaces with corresponding masterpiece so.Can monitor this power.
When adopting this bias method, the seepage of container is blocked when the wall district that seepage is arranged is pressed on the outer surface, in the surf zone that suggestion is contacted a kind of structure is set when the chamber wall bias voltage.This structure can be by adding netted between wall of a container district and outer surface or the trellis parts are realized, perhaps preferably by such as etching or machining the outer surface roughening being realized.
In also having a preferred embodiment, the first power measuring-signal is stored, and difference signal is to produce according to the first power measuring-signal of being stored and second measuring-signal.
In also having a preferred mode of operation, produce difference signal according to the first power measuring-signal of first power measuring-signal of storage and not storage at very first time point.Resulting difference signal is got up as the zero migration signal storage, and the zero migration of the difference signal that produced afterwards is by this zero migration signal compensation of being stored.
In order to detect bigger seepage early, and then detect less seepage, also suggestion was made comparisons biasing force and at least one predetermined threshold of being monitored when the described very first time, point was taken a sample at the latest, this will cause determining very large leakage, and preferably further difference signal and at least one predetermined threshold be made comparisons.
Leak test instrument according to the present invention comprises container compression that is used for making in the test or the bias mechanism that expands, and also comprises on the wall that can be applicable to test chamber and produces the force detector of electrical output signal.The output terminal of force detector is connected on the storage unit, and the output terminal of storage unit is connected on the comparing unit.Second input end of comparing unit links to each other with the output terminal of force detector.
It all is that the so-called bag-type container that is equipped with such as pastes of flexible wall carries out leak test that the present invention is particularly suitable for container.
The present invention relates to the method for closed container that a kind of manufacturing has the ne-leakage at least one flexible wall district, may further comprise the steps:
Bias piece is relatively moved towards described wall district and arrive in the described wall district;
Stop described moving;
Monitor the biasing force on the described container;
At very first time point the described biasing force of monitoring is taken a sample, obtain the first power measuring-signal;
At at least one second time point thereafter the described biasing force of monitoring is taken a sample, obtain the second power measuring-signal;
Produce difference signal as the seepage indicator signal according to the described first and second power measuring-signals;
At another time point the described biasing force of being monitored is taken a sample, thereby obtain another power measuring-signal, if described seepage indicator signal represents that there is not leakage problems in container, utilize described another power measuring-signal to be updated in the average signal of a plurality of another power measuring-signals that the test period of ne-leakage container in the early time takes a sample, and produce described difference signal according to described average signal.
Utilize described seepage indicator signal to get rid of the container that is considered to seepage.
The invention still further relates to a kind of leak test instrument, comprising leak testing closed containers with at least one flexible wall district:
Bias mechanism is used for making container compression or expansion in the test;
Force detector, can be applicable on the chamber wall of testing and produce electrical output signal, the output terminal of described force detector can be operated with storage unit and link to each other, the output terminal of described storage unit can be operated with comparing unit and link to each other as first input end, and second input end of described comparing unit can be operated with the output terminal of described force detector and link to each other;
The unit of averaging, its input end can be operated with the output terminal of described force detector and link to each other, and its output terminal can be operated with the first input end of threshold cell and link to each other, and second input end of described threshold cell can be operated with the output terminal of described force detector and link to each other.
By reading following detailed description and appended claims, the clear more more optimal ways of realizing the inventive method and instrument of one of skill in the art.
Description of drawings
As an example, in the following drawings:
Fig. 1 schematically shows first embodiment according to the instrument of the present invention of the inventive method work, and wherein Shi Yan container carries out bias voltage by compression, and bias piece is arranged on the relative side of container with force detector;
Fig. 2 shows another embodiment according to Fig. 1, and wherein container is placed on the bearing, and bias piece is arranged on the container side relative with bearing with force detector;
Fig. 3 schematically shows another preferred embodiment of Fig. 1 and 2 instrument of the present invention and method, and wherein the bias voltage of container is to realize by the space around the test chamber of finding time;
Fig. 4 is power and time history qualitatively, and the inventive method of being undertaken by instrument of the present invention is described;
Fig. 5 is functional block/signal flow graph schematic and that simplify, is used for illustrating an embodiment according to the instrument of the present invention of the inventive method work;
Fig. 6 schematically shows the storage of preferential employing in the instrument of the present invention and the optimal way of comparing unit in simplified form;
Fig. 7 and 8 is the perspective schematic view that realize the embodiment of the invention shown in Figure 3 and be used for testing the test chamber of bag-type container;
Fig. 9 and 10 schematically shows other preferred feature according to the test chamber of Fig. 3 work;
Figure 11 a to 11c is force signal and time relation curve map, shows the preferred form that instrument of the present invention is realized the inventive method;
Figure 12 is functional block/signal flow graph, is used for illustrating the embodiment of the instrument of the present invention that carries out the described measurement of Figure 11 a to 11c;
Figure 13 is force signal and time relation curve map, the ne-leakage container that shows same type predetermined bias voltage after the time owing to the biasing force statistical distribution that produces as foozle;
Figure 14 is functional block/signal flow graph of simplifying, shows another preferred feature of instrument of the present invention and method, is used for producing adaptive threshold in the embodiment according to Figure 12;
Figure 15 shows the time curve by adaptive change threshold value in the instrument of the present invention of Figure 14 and 16 embodiment realization and the method qualitatively;
Figure 16 shows and is used for self-adaptation in the inventive method that realizes by preferred apparatus of the present invention and adjusts the embodiment of another reference value or threshold value; With
Figure 17 schematically shows the series devices that is used for being installed in series with test container.
Embodiment
Fig. 1 schematically shows according to principle of the present invention.Carry out in the container 1 of leak test, certain zone of wall 3 is flexible.Principle of the present invention is when container 1 is carried out leak test, to utilize drive unit 7 that bias piece 5 is moved on the wall of container 1, then with force detector 9 monitoring reacting force F and according to power F generation electric signal F
ElAs shown in Figure 2, in a kind of preference pattern, force detector 9 is directly connected on the bias piece 5, drives force detector 9 and moves on the flexure region 3 with bias piece 5 relative container 1 walls, and wherein container 1 places such as on the base plate 11.
In another preferred embodiment as shown in Figure 3, the drive unit 7 that is used for making one of them or force detector of bias piece 5 and force detector 9 and bias piece subassembly 5/9 to move with respect to the flexure region 3 of container 1 wall is actually to be realized by pneumatic actuating device.It is static that force detector 9 and bias piece 5 keep in test chamber 13.
Utilize vacuum pump 15 that test chamber 13 is evacuated, thereby produce pressure differential deltap p between the surrounding space of container 1 and its inside, this pressure reduction is from the internal tank directed outwards.So flexible wall part 3 is outwardly-bent and move on the force detector 9, in this preferred embodiment, force detector 9 serves as bias piece and force detector simultaneously.Shown in dotted line, can also depend on that the wall of container 1 is constructed with 1 pressurization of the 16 pairs of containers in compressed gas source, make zone 3 outwardly-bent.
No matter adopt any technology of the present invention, promptly no matter where bias piece 5 and force detector 9 are arranged in, also tube drive device 7 is not to realize by the mechanical actuation device shown in Fig. 1 or 2 or by the pressure reduction that utilizes shown in Figure 3, when container 1 according to Fig. 1 or 2 illustrated embodiments are crushed or when expanding according to preferred embodiment shown in Figure 3, bias piece 5 relatively moves and arrives on the container 1 and bias voltage container 1 makes force detector 9 detect the power F of increase towards container 1.According to Fig. 4, touch the time t of container 1 wall from bias piece 5
0Beginning, when the wall of bias piece 5 further pressure vessels 1, reacting force F increase.At preset time t
1The relative motion of chamber wall 3 and bias piece 5 is stopped.If container is non-leakage, the container wall reaches the balance of shape with regard to not having further reaction, can produce constant reacting force F like this
0
If the big seepage LL shown in process (b) takes place the container under stress, the bias voltage of bias piece moves caused reacting force F and can't reach F at all so
0, at t
1-t
0The time interval after, much smaller power F will be measured or monitor to force detector 9
LL
Therefore, according to the present invention, if bias piece is moved on the chamber wall with predetermined speed or speed, and at preset time interval t
1-t
0Do not reach predetermined power such as F afterwards
0, just can detect big seepage LL.
This behavior of container is preferably than t
1-t
0Just detect after the shorter time interval, therefore just can before the contained material of container is extruded or is drawn in its surrounding space, early stop container being carried out bias voltage by the utmost point.So, a shorter time interval t preferably is set
LL-t
0, and check whether reach predetermined threshold power, F as shown in Figure 4 after this time interval increasing bias voltage
LLIf can not reach predetermined threshold power according to bias voltage process (b), should stop further bias voltage, and make as early as possible on the serious seepage container without any bias voltage.
If container 1 is not serious seepage, the reacting force F that is monitored is increasing bias voltage predetermined time interval t
1-t
0To reach threshold value F on request afterwards
0, thereby the seepage situation of container can only detect afterwards.
Checking whether big seepage LL is arranged and at time t
1End after the further bias voltage of container, preferably be provided with and arrive t
2Predetermined time interval t
2-t
1, the system that is made of container 1, bias piece 5 and force detector 9 reaches balance during this period, such as the balance of container shapes.
So, in a kind of preference pattern, t
2Maximal value be according to t
MaxBe provided with, so t is arranged
2=t
MaxContainer for test does not experience under partial pressure such as the situation of volume change especially like this, does not experience volume change the reacting force of transient phase is reduced, and reduce not to be because seepage.
Arrive t
2The time or at t
2Afterwards, the reacting force F that is monitored is sampled as F
2And store.Arrive t
3Through another time interval t
3-t
2Afterwards, again the reacting force F that is monitored is sampled as F
3And with the reacting force F that has stored
2Make comparisons.Therefore, F
3And F
2Poor Δ F can be used as the seepage indicator signal basically.
As further shown in Figure 4, can also when the rate of rise of container 1 bias voltage, take a sample and store power F
2, then at t
1Stop to wait for that the power F that is monitored arrives according to F again after the further bias voltage in descending slope
2Value, thereby the expression system is stable in fact.In this case, moment t
2To reach the storing value F that presets again by the power F that is monitored
2Limit.
Schematically show the schematic diagram of instrument of the present invention in Fig. 5, its course of work can illustrate by means of Fig. 4.Therefore, for the parts of having introduced will use with earlier drawings in identical reference number.In the test chamber 13 of vacuum, be placed with the container 1 that to test.Vacuum pump 15 is by timing unit 17 control operations.Vacuum pump 15 is preferably with the constant and adjustable speed test chamber 13 of finding time.
Force detector and bias piece subassembly 9/5 are fixedly mounted in the test chamber 13 and the flexible wall district 3 of preferably relative and close container 1.Force detector 9 is owing to the power that acts between zone 3 and force detector/bias piece subassembly 9/5 surface of contact produces electric signal S (F), this surface of contact meaning property as shown in FIG. illustrates and has surface structure 19, leakage when the zone in 3 is positioned at just at the right time that zone 3 contacts with subassembly 9/5 or will the contact position time, surface structure 19 can prevent the seepage of closed region 3.On the lower surface of test chamber 13, preferably be provided with identical structure 19a.
As being schematically shown among the figure, at time t
LLControl and switchgear SW by timing unit 17
1Signal S (F) is delivered to comparing unit 21, thus will moment t
LLOutput signal S (F) and the big seepage indication threshold value S that is preset in the unit 23
0(F
LL) make comparisons.
As long as force signal S (F) is at moment t
LLCan not reach S
0(F
LL), the switch element SW that input end links to each other with S (F)
2Just open, thereby pass through the further bias voltage that control module 25 is ended 15 pairs of containers of vacuum pumps.If S (F) is at moment t
LLAt least reach threshold value S
0(F
LL), so just signal S (F) is transported to another switch element SW
3, and at moment t
2By timing unit 17 control with sample of signal and be stored in the storage unit 27.So, in unit 27 storage according to Fig. 4 in power F
2Value.The output signal of storage unit 27 is transported to comparing unit 28, and at moment t
3By the value F of timing unit 17 controls with signal S (F)
3Also be transported in the comparing unit 28.So comparing unit 28 is t constantly
2Power value and t constantly
3The power value make comparisons.The output signal Δ F of comparing unit 28 expresses the seepage situation of container 1 except big seepage in the test, and big seepage detects in front.
Except the output signal of direct evaluation comparing unit 28, can also control bias voltage according to the variation of output signals of comparing unit 28.So, set up negative feedback control loop (not shown), wherein comparing unit 28 is made comparisons ratings and real-time signal S (F) according to institute's storage signal in the storage unit 27, makes the output signal of comparing unit 28 reduce to minimum as the bias piece of the adjustment unit in the negative feedback control loop.Therefore, the control signal of bias piece 15 is used as the seepage indicator signal.
Fig. 6 shows the storage unit 27 that schematically shows among Fig. 5 and the preferred implementation of comparing unit 28.
The output signal of force detector 9 is input in the converting unit 121 in the subassembly 9/5, and converting unit 121 comprises the analog to digital converter 121a as input stage, is thereafter digital to analog converter 121b.The output signal of converting unit 121 is transported to differential amplifier 123, and differential amplifier 123 also directly receives output signal from force detector 9 in addition.The output signal of the differential amplifier 123 of comparing unit 28 affacts on another amplifier 125 among Fig. 5, and the output signal of amplifier 125 is superimposed on the input signal 128 by storer 127.The input signal of storage unit 127 is from the output terminal of amplifier 125.The same with timing unit among Fig. 5 17, timing unit 129 these structures of control.For power F in the storage map 5
2The signal of value is at moment t
2Timing unit 129 makes unit 121 realize a change-over period, so the analog output signal el of conversion again occurs at analog output
0(F
2).
Simultaneously, from the substantially the same signal S (F) of force detector 9 as signal el (F
2) be applied to second input end of unit 123.So zero-signal will appear in output unit 125.Yet the zero migration signal appears in the output terminal of unit 125 usually, this signal by with Fig. 5 in unit 17 similar timing unit 129 control stores in storage unit 127.At moment t
3(Figure 55), trigger conversion in the unit 121, so direct t occurs from force detector 9 at the input end of amplifier 123
3Moment power F
3The value signal, and from converting unit 121 according to t
2The time power F
2The signal of value storage.And the zero migration signal that is stored in the storage unit 127 is superimposed on the output terminal of unit 123 as the migration signal now, so the signal that obtains at amplifier 125 output terminals is compensated by zero migration.Making can be very accurate to the measurement of the poor Δ F of power among Fig. 4.
With reference in figure 1,2 or 3 any one as can be seen, even utilize vacuum that the wall of container is biased on the force detector, the volume of test chamber 13 neither be crucial with respect to the volume of want test container.Be to estimate pressure in the seepage proving installation of prior art, and be evaluation power in the present invention.When estimating pressure, as when wanting pressure in the test container surrounding space, measuring accuracy depends on the volume that is stayed between test cavity locular wall and the chamber wall to a great extent so, because selected intermediate volume is more little, seepage is just big more to the pressure influence in the intermediate volume.According to the present invention,, the wall of container partly is close on the force detector by the wall part of bias voltage container.The seepage in space will influence measured power towards periphery, and irrelevant with the volume and the relative relative volume of test container of wanting of test chamber of surrounding space.
But, in order to shorten test period, if bias voltage is to be undertaken by vacuumizing of Fig. 3, the test chamber with respect to want test container volume minimum is used in suggestion so.
According to F among Fig. 4
0Selected bias voltage and power and the signal S (F) that sets up can set and selected measurement level.For the embodiment among Fig. 3, the contact area during owing to the bending of flexible wall part on force detector and/or bias piece increases gradually, so set up bigger bias voltage pressure differential deltap p, makes the rising of biasing force F hypergeometric example.Can amplify the signal delta F that adopts according to Fig. 4 like this.But also the precision that can improve whole measuring system greatly also can determine to estimate the scope of signal more easily.
In a preferred embodiment, the bag-like container that certain material is housed is tested according to Fig. 3.In Fig. 7 and 8, show in simplified form according to Fig. 3 test chamber 13 and custom-designedly be used for testing the test chamber of bag-like container or the two halves of test chamber.
According to Fig. 7, be provided with shape in the base 30 and meet the recess 32 that to test bag-like container 34 (dotted line) basically.For instance, in base plate 30, be provided with one or more air intake duct 36, link to each other with the aspiration pump of being used as vacuum pump 15.
The structure of top board 37 and base plate 30 are similar among Fig. 8, have recess 38, and when being placed on top board 37 on the base plate 30, recess 38 forms test chamber or test chamber with recess 32.The same with end face 40a size with 37 bottom surface 40b of two boards 30 and airtight joint if necessary, can be provided with corresponding seal around recess 32/38. Plate 30,37 one of them (perhaps also can be two) is equipped with force checking device 42, and its bigger detection faces 44 matches with the shape of test chamber.Force checking device 42 preferably comes work according to the principle of ohmer, promptly to surface 44 pressurizations, will multiply by contact area according to pressure and produce power, makes ohmer measuring sensor slight bending, thereby produces the electric signal S (F) of Fig. 5.
But, obviously also can use other force detector of different physical principles, preferably use the force detector of mechanical motion minimum.Therefore, as using the piezoelectricity force detector.
Especially in by Fig. 7 and 8 test chamber of two recesses 32 and the 38 test bag-like containers that constitute meet just during the shape of the test container of wanting 1 (bag-like container), impedance by the experiment with measuring external container, especially, can obtain the extraneous information of relevant big seepage, as long as the liquid substance in the container of seepage is forced out or this container of sucking-off, the impedance of external container all can change.As the base plate 30 of Fig. 7 but not shown in the top board 37 of Fig. 8, the inside surface of test chamber can be provided with conductive electrode 44 more respectively.Just link to each other with the input adapter 46 of impedance measurement device 48 every an electrode 44 in the electrode, each middle electrode links to each other with input adapter 49.Impedance measurement device 48 can be measured and exchange and/or dc impedance, preferably measures dc impedance.Therefore, as long as container such as bag-like container 34 are biased and have liquid or pasty mass to be pressed in the test chamber, no matter above-mentioned big seepage measurement result according to Figure 4 and 5 how, measured impedance variation all will be represented seepage in the device 48, and the output signal of impedance measurement device 48 will stop the further bias voltage of container.
In order to clean test chamber, flow out under the situation in the test chamber such as the material in the container of seepage, other pipeline or pipeline (not shown) can be set in test chamber and be connected with liquid and/or gas cleaning medium such as air source, preferably nitrogen and/or band press liquid scouring media can also be provided with the well heater (not shown) with dry and in addition the test chamber of making dirty is cleaned in the sidewall of test chamber.
To introduce a crucial feature by means of Fig. 9 and 10 now,, all preferably possess this feature no matter system is according to Fig. 1 or 2 or according to Fig. 3 work.
No matter be according to Fig. 1 of Figure 10 demonstration or 2 mode, or mode according to the shown Fig. 3 of Fig. 9, as long as testing container 1 is biased, at least two of container relative wall portions, in Fig. 9 and 10, represent with 51a and 51b, to be pressed onto tightly on bias piece/force checking device, perhaps more generally, will be pressed onto tightly on the surface of bias piece/force checking device.When in this zone of container wall seepage taking place, this seepage may be blocked by this surface.So as being schematically shown in Fig. 9 and 10, all surface zone that chamber wall is pushed down during the container bias voltage is provided with surface structure, makes the surface only contact with the wall of container 1, and do not contact with the overwhelming majority of wall at individual other contact area.This can be by being provided with netted between the wall portion of corresponding surface and container 1 or the trellis parts are realized, perhaps can be by such as etching or sandblast surperficial roughening being realized.The mechanical splice point 53 that contacts with cell therefor wall individual areas that schematically shows among Fig. 9 and 10 is that this micromechanism by respective surfaces constitutes.Therefore for the embodiment of Fig. 7 and 9, suggestion is processed to form each plate 30 of recess 32 and 38 and 37 surface with mechanical means, makes it have coarse micromechanism.Can prevent that thus any seepage in the chamber wall is plugged owing to the chamber wall district that seepage takes place is pressed onto on the system surfaces, no matter this surface is the another part on bias piece surface, force detector surface or test chamber surface.
The power and the time curve that record according to the optimal way of the inventive method and instrument shown in Figure 11 a, 11b and the 11c, wherein Figure 11 a represents to have very large seepage VGL, and Figure 11 b represents that little seepage is arranged, and Figure 11 c represents the container ne-leakage.To introduce these accompanying drawings in conjunction with Figure 12, a kind of preferred monitoring unit be shown among Figure 12.
According to Figure 11 a, the timing unit 201 among Figure 12 is at moment t
10The container 1 of beginning bias voltage test is no matter be according to Fig. 1 or 2 or according to the embodiment among Fig. 3.According to the embodiment among Fig. 3, timing unit 201 test chamber 13 that begins to find time.
This uses bias voltage enabling signal BIST/t in Figure 12
10Expression.
After fixing schedule time Δ T, the output signal S (F) of force detector and the first reference signal RFVGL that is preset in the source of presetting 107 are made comparisons.For this reason, by timing unit 201 at moment t
10+ Δ T starts comparing unit 102.
If after time interval Δ T, according to electric signal S (F) institute actual monitoring among Figure 12 to power do not reach value RFVGL according to conditional curve I among Figure 11 a, this just means very big seepage VGL.This is detected when comparer 109 produces output signal VGL.If according to family curve shown in the square 109 of Figure 12, at moment t
11=t
10If the output signal of this comparing unit that+Δ T starts still is in high-value, just there is very big seepage VGL in expression, and this exports at the VGL output terminal.If biasing force F meets and exceeds reference levels RFVGL according to the conditional curve II among Figure 11 a, just can not produce the VGL output signal.
The VGL signal preferably can be ended the bias voltage cycle, only can cause the material in the container in the test is pressed in the surrounding space because continue bias voltage.
Shown in the conditional curve II among Figure 11 a, when VGL did not take place, the container that continues the bias voltage test was to another moment t
13At moment t
13, timing unit 201 drives bias voltage to stop, no matter utilize the vacuum pump 15 of embodiment among the mechanical actuation device 7 of embodiment among Fig. 1 and 2 or Fig. 3.
In addition, the position of timing unit 201 also starts comparing unit 111, and another reference value RFGL that is produced by derived reference signal 113 is transported in the comparing unit 111.If at moment t
13Do not reach RFGL by the detected power of force detector, comparing unit 111 produces the output signal GL that the expression test chamber has big seepage GL so.Equally also to make certain reaction here to the further work of test macro.
If any one among signal VGL or the GL produced by corresponding comparer 109,111, timing unit 201 will be reset, because test has finished and the quality of institute's test container 1 is determined.This uses signal RS in Figure 12
201Schematically show.If at moment t
13Timing unit 201 is not reset immediately afterwards, by value S (the F) (t of the detected power of force detector
13) will be stored in retainer or the storer 117.The output signal of retainer or storer 117 is transported to an input end of differential formation unit 119, and another input end of this unit 119 links to each other with the output signal S (F) of force detector.One can preset originate in t constantly
13Or originate in data storage constantly test period time T in the storer 117
TAfterwards, the difference signal Δ F of power is transported to through test duration T
TAnd in another comparing unit 125 that starts, be schematically shown as unit among Figure 12 121.
By another reference value source 127, reference value Δ FREF is transported in the comparing unit 125.As to be described later, the value that can make Δ FREF is time to time change controllably, and/or the reference value Φ R that can also make the reference of Δ FREF institute time to time change controllably.
If signal delta F is at moment t
13+ T
TGreater than reference value Δ FREF, in unit 125, can produce signal FL so, there is trickle seepage FL in the container 1 of expression test.This meets the situation shown in Figure 11 b.If signal delta F does not reach Δ FREF, container is considered to leak free so, because signal VGL, GL and FL do not have to produce.This meets the situation of Figure 11 c.
No matter be,, should stop further bias voltage immediately so if produced signal VGL according to Figure 12 according to which embodiment among Fig. 1,2 and 3.In Fig. 3 embodiment that uses vacuum pump 15 to drive, should immediately vacuum pump 15 be disconnected with corresponding test chamber 13 as bias voltage.This is that vacuum pump 15 may be polluted by the seepage material of container 1 because under the situation that very big seepage is arranged.
In utilizing many case series connection test macros of Fig. 3 embodiment with a plurality of test chamber, when producing signal GL that expression has big seepage even when producing when representing the signal FL of trickle seepage is arranged, the test chamber that preferably inactive or " bypass " has seepage to take place, in order to avoid continue test with other containers to be tested, and other chamber still can be worked and the container of newly putting into is tested.
Be confirmed as the test chamber 13 of serious seepage and even slight seepage for container wherein, should be with its bypass, in order to avoid influence other test result in this test chamber, can prevent that especially the vacuum pump 15 that is attached thereto from damaging owing to the material in the seepage container is inhaled in the pump.After the container with seepage takes out, can when proceeding test period, other test chamber the test chamber to bypass repair.
Can pass through heat test chamber 13, use liquid and/or gas bleed, preferably use nitrogen, especially heated air is washed and is repaired.
Can see that from Figure 11 a and 11b the setting of the reference value RFGL especially setting of reference load difference DELTA F REF is very crucial, and can have influence on the degree of accuracy of system to a great extent.So the factors such as foozle of environment temperature, container can influence measured force curve, and if these crucial reference levels especially Δ FREF be provided with the accurate inadequately words result that will lead to errors.
The qualitative biasing force curve that shows Figure 11 a to 11b curve in Figure 13, but the container of measured same type has been proved to be ne-leakage.This can obtain by long-term experiment and/or seepage detection system, and these seepage detection systems ten minutes standards also have very high precision, but but very slow and/or very expensive.
At moment t
13Value to the measured power of closed container is slightly different, and forms statistical distribution as shown in figure 13.So have mean value (RFGL)
mBe used in the comparer 111 of Figure 12 or the RFGL value of Figure 11 a to 11c is from (RFGL)
mIn deduct that offset value delta RFGL obtains.When a lot of same containers were tested, the temperature of these containers may be different with foozle.These parameters can slowly change and change (RFGL)
m
In a plurality of long run tests, whenever at corresponding t constantly
13When container was confirmed as not having serious seepage, the real output signal of force detector was sent in as shown in figure 14 the unit 130 of averaging, and the value of last m actual forces of not serious there seepage container averages.The average result signal of being exported meets (RFGL) among Figure 13
m, and can change at any time because the Fabrication parameter of same type of container changes.According to Figure 13 with offset RFGL from output average result
In deduct, thereby obtain the reference value RFGL of dynamic change, reference value RFGL is applied on the comparing unit 111 of Figure 12.The qualitative reference value RFGL that shows this dynamic change among Figure 15, its initial setting up can illustrate by means of the measurement to the ne-leakage test chamber.
From Figure 15, can be clear that the mean force value
(t
13) also be the basis of Δ FREF institute reference now.Therefore, as shown in Figure 12, power difference reference value Δ FREF is not relevant with absolute quiescent value such as Φ R, but and
Relevant.
By realizing dynamic RFGL and, can also further improving precision based on the dynamic upper limit of the Δ FREF of this dynamic RFGL.According to Figure 16, at time interval T
TLast, as long as output signal FL represent to test in container be ne-leakage, actual power difference signal Δ F just is transported in the unit 135 of averaging.The output signal of unit 135 is the mean force difference signals of averaging on m test period in the end
, after being offset with Δ Δ F, its result is used as and is applied among Figure 12 time dependent signal delta FREF on the unit 127.
The Figure 15 that looks back has used constant Δ FREF signal among the figure, and to the technology that Δ F averages can obtain as among the figure with curve (Δ FREF)
tThe dynamic change value Δ FREF that schematically shows, it is that variation according to the excitation parameter that influences this power difference changes.The reference value of dynamic change clearly, needn't be provided
, by (Δ FREF)
tSteady state value Φ R that reference dots as shown in figure 12 rather than dynamic change
Be worth, (the Δ FREF) of the dynamic change shown in Figure 15 just can be provided
tSignal.
Obviously, above-mentioned one or more force detector is preferably undertaken by digital form the evaluation of output signal S (F).
Series devices has been shown among Figure 17, and the A﹠T of container is wherein generally connected and is carried out.For instance, at first the bag-like container in the base plate 30 shown in Figure 7 on the welding bench 60 is welded, wherein base plate 30 is as carrier and assembling bearing.After assembling bag-like container by welding, the carrier that is made of base plate 30 moved to add present a theatrical performance as the last item on a programme, the top board 37 in this Fig. 8 is assembled on the base plate 30.Then, move to the test chamber that is closed on the test board 64 and carry out according to test of the present invention.Therefore by welding bench 60 and/or add present a theatrical performance as the last item on a programme 62 and/or the system that constitutes of test board 64 can be static with respect to the travelling belt 66 of base plate 30.But, depend on the needed time of operating process, especially test board 64 can make that the speed of test process and travelling belt 66 is irrelevant with travelling belt 66 mobile preset times.
By method of the present invention and instrument, a kind of leak test technology is provided, can reach and the identical precision of leak test technology of estimating pressure, but technical requirement is much lower.Make the container bias voltage according to the present invention much simpler than setting up the perfect vacuum around this container, and measure biasing force and also change a lot easily in time than vacuum pressure in the measuring vessel surrounding space accurately.Compare with the power measurement of adopting among the present invention, have more the unknowns and uncontrollable factor to influence in vacuum measurement measuring entity is vacuum pressure.In the vacuum measurement technology measurement level the expense that can influence to a great extent aspect the vacuum pump is set, and biasing force is set and biasing force is changed to save trouble a lot.
Method of the present invention and instrument are particularly suitable for testing bag-like container, but obviously also can be used for testing various containers until very big jar, as long as its wall partly is flexible flexible.The present invention can implement in having the series devices of a plurality of testing tables, and these testing tables are such as being arranged on the carousel with very high transport capacity.
Claims (38)
1. a manufacturing has the method for closed container of the ne-leakage at least one flexible wall district, may further comprise the steps:
Bias piece is relatively moved towards described wall district and arrive in the described wall district;
Stop described moving;
Monitor the biasing force on the described container;
At very first time point the described biasing force of monitoring is taken a sample, obtain the first power measuring-signal;
At at least one second time point thereafter the described biasing force of monitoring is taken a sample, obtain the second power measuring-signal;
Produce difference signal as the seepage indicator signal according to the described first and second power measuring-signals;
At another time point the described biasing force of being monitored is taken a sample, thereby obtain another power measuring-signal, if described seepage indicator signal represents that there is not leakage problems in container, utilize described another power measuring-signal to be updated in the average signal of a plurality of another power measuring-signals that the test period of ne-leakage container in the early time takes a sample, and produce described difference signal according to described average signal.
Utilize described seepage indicator signal to get rid of the container that is considered to seepage.
2. method according to claim 1 further comprises and selects described another power measuring-signal as the described first power measuring-signal.
3. method according to claim 1 comprises that also the described wall of bias voltage district reaches predetermined bias power.
4. method according to claim 3 is characterized in that, is reaching described predetermined bias power and is carrying out setting interval between time of described sampling.
5. method according to claim 1 also comprises according to the variation of described difference signal and controls described bias voltage, makes described difference signal keep predetermined value, and the corresponding actions of described bias piece is indicated as seepage.
6. method according to claim 1 also comprises by form pressure reduction between the inside of described container and surrounding space and carries out described mobile step.
7. method according to claim 6 also comprises by the described surrounding space of finding time forming described pressure reduction.
8. method according to claim 1 is provided with a kind of structure at the surf zone that contacts with described chamber wall when also comprising described container bias voltage.
9. method according to claim 1 also comprises storing the described first power measuring-signal.
10. method according to claim 9, also be included in described first power measuring-signal and the described first power measuring-signal generation difference signal of described very first time point according to storage, described difference signal is got up as the zero migration signal storage, and produce the zero migration of described difference signal with the zero migration signal compensation of described storage.
11. method according to claim 1 comprises also when putting sampling in the described very first time at the latest that described biasing force and at least one predetermined threshold of monitoring are made comparisons, and described predetermined threshold is decided according to described average signal.
12. method according to claim 1 also comprises described difference signal and at least one predetermined threshold is made comparisons.
13. method according to claim 1 also is included in described very first time point and starts analog to digital converter and change and store the described first power measuring-signal.
14. method according to claim 13 comprises that also the digital output signal with described analog to digital converter is converted to simulating signal again, and with described again the conversion the described difference signal of analogue signal generating.
15. method according to claim 1, also be included in described chamber wall or carry out preferably direct current resistance measured impedance measurement near described chamber wall place at least, and make described bias piece further move and arrive in the described wall district, or end being moved further of described bias piece towards described wall district according to the result of described impedance measurement.
16. method according to claim 1 also comprises with ohmer and monitors described biasing force.
17. method according to claim 1, also be included in earlier than the 3rd time point of described very first time point and the described biasing force of being monitored is taken a sample and obtain the 3rd power measuring-signal, described the 3rd power measuring-signal and the threshold signal that presets are made comparisons, if produce big seepage indicator signal just described the 3rd power measuring-signal can not reach described threshold signal.
18. method according to claim 1 also is included as described container test chamber is provided, and container has therein detected after the seepage, clean described test chamber, described Clean-gas washes, preferably nitrogen, and/or use liquid wash, and/or undertaken by heating.
19. method according to claim 1, also being included in one group of test chamber series connection test a series of described containers, but also comprising when the container of being tested in a certain test chamber and being proved to be to reaching after the predetermined leakage step of test at least one test period in the described test chamber of termination.
20. method according to claim 1 is further comprising the steps of:
Make described bias piece move and arrive in the described wall district with set rate towards described wall district;
By monitoring described biasing force after the described mobile schedule time, and whether the biasing force that detects described monitoring has reached first predetermined threshold and has differentiated big seepage.
21. method according to claim 1 also comprises making described bias piece move and arrive in the described wall district towards described wall district with constant speed.
22. method according to claim 1 also comprises with the prearranged signals amount being offset described average signal, produces described difference signal according to the average signal of described skew.
23. method according to claim 1 also comprises described difference signal and at least one threshold signal is made comparisons.
24. method according to claim 23, also comprise, if there is not leakage problems in the container container of being tested, utilizes described difference signal to be updated in another average signal of the difference signal of container test period in the early time, and control described threshold value according to described mean value.
25. the leak test instrument to leak testing closed containers with at least one flexible wall district comprises:
Bias mechanism is used for making container compression or expansion in the test;
Force detector, can be applicable on the chamber wall of testing and produce electrical output signal, the output terminal of described force detector can be operated with storage unit and link to each other, the output terminal of described storage unit can be operated with comparing unit and link to each other as first input end, and second input end of described comparing unit can be operated with the output terminal of described force detector and link to each other;
The unit of averaging, its input end can be operated with the output terminal of described force detector and link to each other, and its output terminal can be operated with the first input end of threshold cell and link to each other, and second input end of described threshold cell can be operated with the output terminal of described force detector and link to each other.
26. instrument according to claim 25 is characterized in that, described bias mechanism comprises a pair of parts that separate, can drive that described parts move relative to each other and near and leave.
27. instrument according to claim 26 is characterized in that, described at least one force detector one of is installed in the described parts.
28. instrument according to claim 25 also comprises the blocking test chamber that links to each other with vacuum pump, described force detector is fixedly mounted in the described test chamber, and its power sensing surface is exposed to described test chamber inside.
29. instrument according to claim 25 is characterized in that, comprises ohmer in the described force detector.
30. instrument according to claim 25 also comprises timing unit, is used for controlling described storage unit and stores with second time point of described comparing unit after described very first time point at very first time point and compare.
31. instrument according to claim 25 is characterized in that, described storage unit comprises analog to digital converter.
32. instrument according to claim 25, it is characterized in that, described comparing unit comprises differential input stage, the output terminal of its input end and described force detector and the output terminal of described storage unit can be operated and link to each other, the output terminal of described input stage can be operated with another storage unit and link to each other, and the output terminal of described another storage unit feeds back to the input end of described comparing unit.
33. instrument according to claim 25 also comprises can evacuated test chamber being arranged in the described test chamber and with impedance measurement device with at least one pair of and can operate the electrode that links to each other.
34. instrument according to claim 33 is characterized in that, the surface of the described test chamber that contacts with the container of being tested has a kind of surface structure.
35. instrument according to claim 34 is characterized in that, described surface structure is inlayed formation by grid, or forms by described surface being carried out surface roughening processing.
36. instrument according to claim 25 also comprises the first threshold sensing device, an one input end can be operated with the output terminal of described force detector and link to each other, and its output terminal can be operated with the control input end of described bias mechanism and link to each other.
37. instrument according to claim 36 also comprises the second threshold value sensing device, its input end can be operated with the output terminal of described force detector and link to each other, and comprises the timing unit that can start the described first and second threshold value sensing devices at different time points.
38. instrument according to claim 25, also comprise another unit of averaging, its input end can be operated with the output terminal of described comparing unit and link to each other, its output terminal can be operated with threshold cell and link to each other as first input end, and second input end of described threshold cell can be operated with described comparing unit and link to each other.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007101419309A CN101126671A (en) | 2000-09-26 | 2000-09-26 | Method and instrument for carrying out leakage test for closed container |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007101419309A CN101126671A (en) | 2000-09-26 | 2000-09-26 | Method and instrument for carrying out leakage test for closed container |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB008199108A Division CN100342225C (en) | 2000-09-26 | 2000-09-26 | Method and apparatus for leak testing closed containers |
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| CN101126671A true CN101126671A (en) | 2008-02-20 |
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| CNA2007101419309A Pending CN101126671A (en) | 2000-09-26 | 2000-09-26 | Method and instrument for carrying out leakage test for closed container |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106323570A (en) * | 2016-11-09 | 2017-01-11 | 深圳市欧盛自动化有限公司 | Method for detecting liquid leakage of soft-packing battery and leakage detector |
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2000
- 2000-09-26 CN CNA2007101419309A patent/CN101126671A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106323570A (en) * | 2016-11-09 | 2017-01-11 | 深圳市欧盛自动化有限公司 | Method for detecting liquid leakage of soft-packing battery and leakage detector |
| CN106323570B (en) * | 2016-11-09 | 2020-05-15 | 深圳市欧盛自动化有限公司 | Method for detecting leakage of soft package battery and leakage detector |
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