DE102019104097A1 - Test device and test method - Google Patents

Abstract

The present invention relates to a test device (1) with: - a test chamber (10) in which at least one test object (20) can be arranged, - at least a partial area (15) of the test chamber (10) optionally with a liquid heat transfer medium (30) and a gaseous heat transfer medium (40) can be acted upon in order to heat or cool the immediate vicinity of the test object (20) in accordance with predeterminable test cycles.

Description

Technical area

The present invention relates to a test apparatus and a test method. In particular, it relates to a test device for performing thermal tests on test objects which are arranged in a test chamber. The test device and the test method are designed in particular to carry out environmental simulations and / or thermal shock tests.

Test devices and test methods for performing specified thermal test cycles on test objects are well known in the prior art. For example, the EP 2 743 675 A1 a test system, comprising a test chamber for receiving objects to be tested, in which at least one temperature control unit is provided for a gaseous test medium present in the test chamber in order to heat and cool the test medium according to predeterminable test cycles.

In order to carry out thermal shock tests, it is also known to flow around the test object or objects in a test chamber with a gaseous heat transfer medium in order to bring the test object or objects to a first test temperature. Then the test object or objects can be immersed by means of a device, for example, in a liquid heat transfer medium, for example water, which has a second temperature which differs from the first temperature. In particular, so-called thermal shock tests can be carried out in this way.

The immersion of test objects in a liquid heat transfer medium requires the test objects to be movably mounted inside the test chamber, which should typically be closed during the test cycle. In this respect, a sometimes complex mechanism must be provided for moving the test objects. Often the test items are wired during the test cycle in order to test their functionality and / or properties during the test cycle. Sometimes complex cabling makes the moving arrangement of test objects inside the chamber all the more complicated. Movable storage of test objects inside the test chamber is also at the expense of the space available in the chamber for receiving test objects. Furthermore, there are restrictions with regard to the maximum possible weight of the test items due to the mechanics.

In contrast, it is desirable to provide an improved test device and a corresponding test method in which at least two heat transfer media are used and in which the test object or objects can be arranged and fixed in a stationary manner in the chamber.

This object is achieved with a test device and with a method for thermal testing of at least one test object in accordance with the independent patent claims, with advantageous embodiments of the invention being the subject matter of the dependent patent claims.

To this extent, a test device is provided which has a test chamber in which at least one test item can be arranged. At least a partial area of the test chamber can optionally be acted upon with a liquid heat transfer medium and a gaseous heat transfer medium. The partial area can be acted upon, or acted upon or filled, either with the liquid heat transfer medium or with the gaseous heat transfer medium at one time.

In the event of a change from gaseous to liquid heat transfer medium provided according to the test cycle, the gaseous heat transfer medium can be displaced by the liquid heat transfer medium. The partial area of the test chamber can be flooded with the liquid heat transfer medium. The optional or alternating application of the liquid and the gaseous heat transfer medium to the sub-area of the test chamber makes it possible to heat or cool the immediate surroundings of the test item or the test item in accordance with predefined or specified test cycles by means of gaseous and liquid heat transfer media at different temperatures.

The test cycle can be designed in accordance with a specified test standard or it can map such a test standard. The test cycle specifies in particular the length of time or the time interval for which the test object (s) should remain at a specified temperature level. The test cycle also specifies a time change or a time gradient of the temperature change for the test object.

The fact that the sub-area of the test chamber provided for receiving the test item (s) can optionally be acted upon, filled or flooded with a gaseous heat transfer medium and a liquid heat transfer medium, the test item can be stationary during the entire test cycle, i.e. during several successive heating or cooling phases remain in the sub-area of the test chamber. The test specimen can in particular be arranged or fixed in the partial area of the test chamber. In this way, moving the test specimen during the test cycle can be avoided.

With the possibility of fixation, especially in the case of vibration and / or movement-sensitive test objects such. B. sensors, an undesired influence of the movement of the test object on a measurement or test result can be avoided.

Corresponding and hitherto customary adjustment or movement mechanisms for moving the test object inside the test chamber are thereby dispensed with. The suspension or arrangement of individual test items inside the test chamber can be simplified. As a result, manufacturing and servicing or maintenance costs for the test device can be reduced. Furthermore, due to the comparatively simple holding and / or fixing of the test items inside the test chamber, with the outer dimensions of the test chamber remaining the same, a larger test space can be made available as any devices and / or arrangements for moving the test item (s) are no longer required.

According to a further development of the test device, the test chamber has at least one inlet and at least one outlet for the liquid heat transfer medium. The liquid heat transfer medium can flow into or be introduced into the test chamber via the inlet. The liquid heat transfer medium can be diverted from the test chamber or from the partial area of the test chamber via the drain.

In particular, it can be provided here that the liquid heat transfer medium circulates through the test chamber or through its partial area during the current test cycle. In particular, it can be provided that, for example, at the beginning of a test cycle, the sub-area of the test chamber is initially filled with the gaseous heat transfer medium, for example with air, or filled with air. The air or the gaseous heat transfer medium can be heated to a predetermined first temperature level.

When a thermal equilibrium is reached, or after some time, the test item can have a temperature level corresponding to the temperature of the gaseous heat transfer medium. As soon as this is provided after the test cycle, the liquid heat transfer medium can typically be introduced into the test chamber via the inlet by means of a control provided for this purpose. The gaseous heat transfer medium is hereby displaced from the test chamber, but at least from the sub-area to which the liquid heat transfer medium can be applied. The liquid heat transfer medium can flow into the test chamber via the inlet until the partial area of the test chamber is completely flooded with the liquid heat transfer medium.

As soon as the partial area is completely filled with the liquid heat transfer medium, the inflow of the liquid heat transfer medium can also continue unabated. Alternatively, the flow can be throttled or completely interrupted. If the inflow of the liquid heat transfer medium continues unabated or throttled even after the partial area has been completely flooded, the excess heat transfer medium is discharged from the test chamber via the drain. A continuous inflow of the heat transfer medium into the sub-area of the test chamber is particularly advantageous for maintaining a predetermined temperature level in the sub-area of the test chamber that is flushed or flooded by the liquid heat transfer medium. The inflow of the liquid heat transfer medium can also be regulated continuously or discretely, or in steps, depending on a temperature measured in the partial area of the test chamber.

According to a further embodiment, the test device has a holder arranged within the test chamber, by means of which the at least one test object can be arranged in a stationary manner in the sub-area. By means of the holder, the at least one test item can be permanently fixed in the sub-area of the test chamber which can be alternately flooded or filled by the liquid and gaseous heat transfer media. In this context, a stationary arrangement of the test object means an immobile or unchangeable arrangement of the test object in the partial area of the test chamber. The holder itself can be stationary and immovable in the interior of the test chamber.

The holder can, for example, also be configured to be adjustable or reconfigurable, for example in order to mount or fix the test object (s) in a predetermined position inside the test chamber. However, the holder is designed free of any servomotors or mechanical drive elements, so that the holder cannot be modified from the outside or its configuration changed during a test process.

According to a further embodiment, the test device has a test pan that can be arranged in the test chamber. This is typically arranged in the test chamber. The test tank is also can be filled with the liquid heat transfer medium. The test tub typically has a base and at least one, possibly also several side walls adjoining one another in the circumferential direction of the base. The tub is designed to be fluid-tight and serves to form the portion of the test chamber that can be exposed to the liquid heat transfer medium. In particular, the test tub can form the sub-region of the test chamber which can be filled or flooded with the liquid heat transfer medium.

The provision of a separate test tub inside the test chamber has proven to be advantageous in terms of production. In particular, the test tub can be designed as an insert that can be arranged in the test chamber. For the manufacture or manufacture of the test device, for example, an already existing test chamber can be used. This can, if necessary, also be retrofitted for the intended purpose by means of the test tank.

According to a further embodiment, the test tub has a bottom into which the inlet opens. In particular, it can be provided that the inlet passes through the floor of the test chamber and finally opens into the floor of the test tub arranged in the interior of the test chamber. A bottom inlet allows the test tank to be flooded from below, so that, for example, in accordance with a specified test cycle when the liquid heat transfer medium rises in the test tank, immersion of the test item in the liquid heat transfer medium can be simulated, although the test item is stationary or immovable in the chamber.

The arrangement of the inlet on the floor or the integration of the inlet in the floor of the test tank also has the advantage that, for the test to be carried out with the test device, premature only partial wetting of the test item (s) with the liquid heat transfer medium can be largely avoided. If the heat transfer medium is fed in from the bottom, possibly also in a surge, splashing and the associated only partial wetting of the test item (s) can be largely avoided. As soon as the test items come into contact with the liquid heat transfer medium rising from below, they are almost completely immersed in the liquid heat transfer medium and completely enclosed by it.

According to a further embodiment of the test device, a baffle plate for the liquid heat transfer medium flowing into the test tank is arranged above the floor of the test tank and at a predetermined distance from the floor in an imaginary extension of the inlet. The baffle plate prevents the liquid heat transfer medium from being introduced into the test tank in the manner of a fountain. It is true that the liquid heat transfer medium can be introduced into the test tank in a comparatively surge-like manner and quickly, i.e. on the basis of a comparatively high volume flow, so that the test tank is completely flooded with the liquid heat transfer medium within a few seconds, for example. The provision of a baffle plate in an imaginary extension of the bottom inlet prevents uncontrolled or undesired premature splashing or wetting of the test object or objects arranged in the interior of the test tub.

The baffle plate can have at least one through opening which is arranged horizontally offset to the inlet. Here, the baffle plate can extend, for example, over the entire floor of the test tub. In another embodiment, the baffle plate can have external dimensions or an area which are smaller than the corresponding external dimensions or the area of the bottom of the test tub. In any configuration, the liquid heat transfer medium flowing into the test tank via the inlet, for example, can flow onto the underside of the baffle plate and then spread over the bottom of the test tank until the test tank is completely flooded with the liquid heat transfer medium.

According to a further embodiment, the test tank has at least one side wall with an overflow. The overflow is typically in flow connection with the drain leading out of the test chamber. The overflow is located above the inlet in relation to a vertical line. The overflow and / or the outlet can have a flow cross-section which is at least as large as the flow cross-section of the inlet. In this way it can be ensured that a volume flow of the liquid heat transfer medium in the area of the overflow and / or the drain is at least as large or greater than a volume flow of the liquid heat transfer medium in the area of the inlet. In this way, uncontrolled overflow of the test tank can be effectively avoided.

A plurality of side walls adjoining one another can also be provided, each with one or more overflows, all of which lead into the at least one drain or into several drains.

The overflow can in particular be designed as a funnel-like lateral extension of the side wall. In particular, one of the Side walls of the test tank or a side wall area of the test tank, relative to the vertical, can be designed to be somewhat shorter than the adjacent side walls or side wall areas. In this somewhat shorter side wall section or side wall area, the funnel-like, downwardly tapering overflow can be designed so that excess liquid heat transfer medium always flows into or drains off into the overflow and finally into the drain before it reaches an upper side wall area facing away from the bottom of the test tub.

A test cycle can also be implemented by means of the inflow on the bottom side and the outflow on the side wall, in which the test object (s) are continuously flowed around by a liquid heat transfer medium in such a way that a continuous flow of the liquid heat transfer medium flows into the test tank via the inflow and a volume flow of equal magnitude over the test tank the drain flows out of the test tank.

According to a further embodiment of the test device, it has a buffer basin designed to accommodate the liquid heat transfer medium. The buffer basin is located outside the test chamber. It can at least be coupled fluidically to the inlet.

The buffer basin enables the implementation of a required volume flow of liquid heat transfer medium, which can be introduced into the test chamber or into the test tub via the inlet. In principle, the test device can also be designed or operated without a buffer basin, provided that it is ensured that, for example, a sufficiently large volume flow of the liquid heat transfer medium can be provided from an external source. However, this depends on the operating location of the test device. By means of the buffer basin, the test device can be operated independently of location, that is to say at any location that is basically suitable for this.

According to a further embodiment, at least one heat exchanger for controlling the temperature of the liquid heat transfer medium is arranged in the buffer basin. The heat exchanger can be heating or cooling coils that are thermally coupled, for example, to a heater or a refrigeration machine. The heater or the refrigeration machine can be arranged directly adjacent to the buffer basin. The provision of a heat exchanger or a heater or a refrigeration machine is sometimes not absolutely necessary if the test device should be operated in an environment in which a heat reservoir suitable for the test purposes, for example a thermal coupling to an external heating or cooling system, is already available.

According to a further embodiment, the buffer basin can be fluidically coupled to the drain. In this case, it is provided in particular that the liquid heat transfer medium flowing out of the test chamber or from the test tub via the drain is conducted back into the buffer basin. In this respect, a circuit can be provided for the liquid heat transfer medium.

By means of the buffer basin, a comparatively large amount or a large volume of the liquid heat transfer medium can also be brought to a predetermined temperature level before the liquid heat transfer medium preheated in this way is introduced into the test chamber or into the test tub. In this way, a thermal shock test can be carried out particularly well for the test object or objects inside the test chamber. The liquid heat transfer medium can be, for example, comparatively cold water, possibly also ice water, which can be provided with anti-freeze additives.

The temperature of the liquid heat transfer medium can be between -65 ° C and + 200 ° C. In particular, it can be between -10 ° C and 95 ° C. The liquid heat transfer medium can in particular comprise salt water or consist of salt water. In the case of salt water as the liquid heat transfer medium, the temperature of the liquid heat transfer medium can be between -10 ° C and 95 ° C. The temperature of the gaseous heat transfer medium can be above the temperature of the liquid heat transfer medium; the temperature of the gaseous heat transfer medium can, depending on the specified test cycle, also be below the temperature of the liquid heat transfer medium.

The fluidic coupling between the buffer basin and the drain makes it possible to guide any liquid heat transfer medium from the test basin via the overflow into the drain back into the buffer basin so that it can mix there with the remaining liquid heat transfer medium at the specified temperature level.

In particular, it is provided that the maximum filling volume of the buffer store is greater than the maximum filling volume of the test tub. In particular, the size of the buffer basin can be at least 1.5 times, at least 2 times, at least 3 times, at least 5 times or at least 10 times the volume of the Have test tub. The larger the volume of the buffer basin and the filling level with the pre-tempered liquid heat transfer medium, the better and easier it is - provided that the liquid heat transfer medium is continuously circulated between the test basin and the buffer basin - a required temperature level can be stable in the area of the test basin or the partial area of the test chamber are adhered to, or a temperature change in the partial area of the test chamber occurs comparatively quickly and easily.

According to a further embodiment, the buffer basin and the test chamber are arranged at different height levels with respect to a vertical. This enables the liquid heat transfer medium to flow into or out of the test tub or from the test tub under the action of gravity. If the buffer tank is above the test chamber, the liquid heat transfer medium can flow into the test tank under the action of gravity. If the buffer basin is below the test chamber, the liquid heat transfer medium located in the test chamber can flow back into the buffer basin due to gravity.

According to a further embodiment, the test chamber is arranged above the buffer basin. In particular, the floor of the test chamber or the floor of the test tub is located above the buffer basin or above a maximum fill level of the buffer basin. In this way it can be ensured that even in the event of a possible failure of fluid-conveying components of the test device, the liquid heat transfer medium can always be drained from the test chamber back into the buffer basin.

Typically and according to a further embodiment, a fluid-conveying pump is arranged between an outlet of the buffer basin and the inlet. The pump can in particular be controlled or regulated by a controller of the test device. By means of the fluid-conveying pump, the liquid heat transfer medium located in the buffer basin, for example, can be introduced into the test chamber or into the test tub arranged therein as required. In the event of a pump failure or malfunction, the arrangement of the test chamber and buffer basin at different levels ensures that the liquid heat transfer medium will always drain from the test chamber back into the buffer basin.

According to a further embodiment, the buffer basin has an inlet which can be fluidically coupled to the inlet of the test chamber by means of at least one valve. The inlet of the buffer basin is typically below the inlet of the test chamber, based on a vertical. In the event of a pump failure, a fluidic connection between the test tub and the inlet of the buffer basin can be provided by opening the valve, that is, by forming a flow connection between the inlet and the inlet of the buffer basin. The liquid heat transfer medium located in the test tank can flow back through the valve into the inlet of the buffer tank via the inlet of the test chamber on the bottom side.

Alternatively, the fluid-conveying pump, which is typically in flow connection with the inlet, can be switched to an idle or open-circuit mode, so that the liquid heat transfer medium located inside the test tank counter to the actual flow direction through the inlet via the inlet of the test chamber or the test tank fluid-conveying pump and can flow back into the buffer basin via the outlet of the buffer basin. In this way, the test tub can be emptied purely due to gravity, for example, before it is filled again with the gaseous heat transfer medium or subjected to it.

It is also conceivable that the pump changes its conveying direction or that such a flow connection is created by means of a valve arrangement provided for this purpose, so that the pump can also actively pump out the liquid heat transfer medium located inside the test tank. Thus, the test tub can be emptied of the liquid heat transfer medium particularly quickly.

According to a further embodiment of the test device, at least one side wall adjoining the partial area of the test chamber has a flow channel that can be acted upon by the gaseous heat transfer medium. This can be acted upon by means of a fan and a heating and / or cooling device with the gaseous heat transfer medium heated to a predetermined temperature. The flow channel can run between a side wall of the test tub and a side wall of the test chamber. The flow channel can also be integrated directly into the test tub.

For example, a side wall or a side wall section of the test tub can be double-walled, with only an outer side of the at least partially double-walled test tub facing a side wall of the test chamber being connected to the bottom of the test tub in a fluid-tight manner. An inner wall of the The double-walled design of the test tub can be designed without contact with the bottom of the test tub. The gaseous heat transfer medium can flow into the flow channel or flow out of it through such a slot or such an opening between the bottom of the test tub and an inner wall of the test tub. The flow channel enables a defined and controllable circulation of the gaseous heat transfer medium inside the test chamber.

According to a further embodiment of the test device, it also has a control and at least one sensor which is connected to the control in a signal-transmitting manner. The control is designed for the optional loading of the partial area of the test chamber with the liquid heat transfer medium or the gaseous heat transfer medium. In particular, the controller is connected in a signal-transmitting manner to the at least one fluid-conveying pump for the liquid heat-transfer medium and also to the fan and / or the heating and / or cooling device in a signal-transmitting manner.

The control is designed in particular to control the temperature of the immediate surroundings of the test object in accordance with the specified test cycle or specified test cycles by means of the liquid heat transfer medium and by means of the gaseous heat transfer medium. Because the controller is coupled to at least one sensor to transmit signals, a control loop can be provided so that the controller can be configured, for example, depending on temperatures measured in the area of the test chamber, to control and / or close the heating and / or cooling device regulate, as well as adjust and regulate volume flows of the gaseous heat transfer medium and / or the liquid heat transfer medium during the test cycle as required.

According to a further aspect, the invention also relates to a method for testing at least one test object by means of the test device described above. The method comprises the steps of arranging the at least one test object in the test chamber and alternately applying the liquid heat transfer medium and the gaseous heat transfer medium to at least a partial area of the test chamber. The method is characterized in particular by the fact that the test item is held or fixed stationary and immovable in the test chamber during the test cycle or during successive test cycles and that the partial area of the test chamber is optionally or alternately exposed to or alternately exposed to the liquid heat transfer medium and the gaseous heat transfer medium. is flooded or filled.

The liquid and gaseous heat transfer medium typically have different temperatures when they are introduced into the test chamber. In particular, the liquid heat transfer medium is brought to a predetermined temperature level outside the test chamber. The gaseous heat transfer medium can typically be brought to the predetermined temperature with a heating and / or cooling device arranged within the test chamber after it has been introduced into the test chamber.

The method provided here can be carried out in particular with the test device described above. In this respect, all of the features, advantages and possible applications described in the course of the test device also apply to the method; and vice versa.

Figure list

• 1 eine perspektivische schematische Darstellung der Prüfvorrichtung,
• 2 eine schematische perspektivische Darstellung der Prüfkammer,
• 3 eine teiltransparente Frontansicht der Prüfkammer bei abgenommener oder geöffneter Tür,
• 4 eine perspektivische isolierte Darstellung der Prüfwanne,
• 5 eine weitere Darstellung der Prüfwanne gemäß 4, jedoch mit zumindest einem darin angeordneten Prüfling,
• 6 eine teilweise transparente Darstellung der Prüfwanne gemäß der 4 und 5,
• 7 eine ausschnittsweise und bereichsweise vergrößerte Darstellung der Prüfvorrichtung gemäß 1,
• 8 ein Blockschaltbild der Prüfvorrichtung,
• 9 einen Querschnitt durch die Prüfkammer gemäß 2. und
• 10 ein Flussdiagramm, welches einzelne Schritte des Prüfverfahren schematisch darstellt.

Further goals, features and advantageous possible uses of the test device and the method are explained in more detail in the following description of an exemplary embodiment with reference to the drawings. Here show:

• 1 a perspective schematic representation of the test device,
• 2 a schematic perspective view of the test chamber,
• 3 a partially transparent front view of the test chamber with the door removed or open,
• 4th a perspective isolated illustration of the test tank,
• 5 a further representation of the test tank according to 4th , but with at least one test item arranged in it,
• 6th a partially transparent representation of the test tank according to FIG 4th and 5 ,
• 7th a section and area enlarged view of the test device according to 1 ,
• 8th a block diagram of the test device,
• 9 a cross section through the test chamber according to 2 . and
• 10 a flowchart which shows the individual steps of the test method schematically.

Detailed description

In 1 is an exemplary embodiment of a test device according to the claims 1 shown in perspective. The testing device 1 has a support frame 3 on. On or on the support frame 3 is a test chamber 10 arranged. The test device also has a controller 2 by means of which, for example, an environmental simulation inside the test chamber 10 is feasible. The test chamber 10 is used to accommodate one or more test items 20th who, for example, in 5 is shown schematically or are. With the test items 20th it can be a wide variety of objects, for example electrical or electronic components, which are to be tested according to a specified test cycle in different thermal or other environmental conditions. On the support frame 3 is also a heater or a refrigeration machine 5 arranged, by means of which in particular a liquid heat transfer medium 30th can be cooled or heated to a predetermined temperature level.

The test chamber 10 is in 2 shown in more detail. The test chamber 10 has a cubic body with a bottom 14th and with several side walls 16 on. The test chamber 10 is by means of an in 2 door shown schematically 8th closable, for example hermetically closable. The test chamber 10 also has an in 9 shown rear wall 13th on. The test chamber 10 also has a floor 14th opposite ceiling 14a on. In the area of the opposite side walls 16 is one implementation each 18th educated. The implementation 18th in particular has a through opening in the side wall 16 on. By performing 18th Individual cables or measuring lines can be passed through, in particular around the one or more inside the test chamber 10 arranged test objects 20th signaling with an evaluation unit or with the controller 2 connect to. The implementation 18th can be sealed fluid-tight and / or gas-tight, or largely fluid-tight and / or gas-tight, with a sleeve or cuff (not shown).

At least one of the side walls 16 can at one of the door 8th adjacent cheek section a recess 19th exhibit. This can be designed as a so-called notch bushing. With the door open 8th For example, very thick cabled plugs can be used in the interior of the test chamber 10 which, due to their size, cannot be introduced through the cable gland 18th would fit through.

In the area of the ceiling 14a is an exhaust valve 6th arranged. This corresponds to one in the area of the rear wall 13th arranged supply air valve 4th . By means of the supply air valve 4th can fresh air into the interior of the test chamber 10 pour in. Using the exhaust valve 6th can remove excess air from the interior of the test chamber 10 with the door closed 8th be pushed outwards.

In the area of the ceiling 14a is also a heating and / or cooling device 75 intended. Furthermore, the ceiling 14a another through opening 36 for a float arrangement 32 on. It is also on or in the ceiling 14a a blower 72 for air circulation or for air or gas circulation in the interior of the test chamber 10 intended. By means of the heating and / or cooling device 75 and the fan 72 can be the interior of the test chamber 10 be brought to a required temperature level by means of heated or cooled circulating air.

As also in the 3 and 4th shown, the test chamber 10 an inlet 11 for a liquid heat transfer medium 30th on. The test chamber has the same 10 also a sequence 12 for the liquid heat transfer medium. As in 8th shown, the process ends 12 via an inlet 61 in a buffer storage 60 . The inlet opening into the test chamber 11 stands with an outlet 62 of the buffer memory 60 in flow connection. By means of the inlet 11 and the process 12 can be the interior of the test chamber 10 , especially a sub-area 15th the test chamber 10 , with the liquid heat transfer medium 30th be flooded as required. In the floodable area 15th is at least one examinee 20th immovably arrangeable or immovably fixable.

By means of the inlet 11 and the process 12 can at least the sub-area 15th the test chamber 10 optionally with the liquid heat transfer medium 30th acted upon or flooded. The sub-area 15th but can also with or with the gaseous heat transfer medium 40 acted upon or filled or by the gaseous heat transfer medium 40 fill out. When flooding the sub-area 15th can excess gaseous heat transfer medium via the exhaust valve 6th to the environment of the test chamber 10 be handed in. When the liquid heat transfer medium is drained 30th from the sub-area 15th can the gaseous heat transfer medium 40 , for example room air, back into the test chamber 10 be sucked in. During a recirculation mode of the test chamber 10 , that is, while the test chamber 10 solely and exclusively with the gaseous heat transfer medium 40 is filled, are the supply air valve 4th and the exhaust valve 6th typically closed to an exchange of the gaseous Heat transfer medium 40 to avoid with the ambient air.

In the interior of the test chamber 10 is also a test tank 50 arranged in the 4th to 6th is shown in different representations. The test tub 50 has a bottom 51 on which the inflow 11 flows out. The floor 51 has two funnel-shaped sloping bottom sections 51a , 51b on, each from opposite side walls 52 the test tank 50 in a central area of the floor 51 extend. The side walls 52 the bottom sections run away 51a , 51b slightly down. In this respect, they each form one of the side walls 52 groundbreaking and downward sloping, each in the inlet 11 flow out. The test tub 50 has one of the two side walls 52 and the floor 51 interconnecting rear wall 56 on.

Of course, the tub has 50 also a corresponding front wall opposite the rear wall, which is not shown here for illustration purposes. At least one of the side walls 52 is with an overflow 54 provided, which fluidly with the drain 12 is in flow connection. The overflow 54 forms an upper area of the side wall 52 . It has a funnel-shaped receptacle 54a on the side of the shortened in this respect and designed in 4th side wall shown 52 adjoins. The recording 54a tapers into the drain 12 , which is tubular along the outside of the shorter side wall 52 runs.

The interior of the test tank 50 forms the sub-area 15th , which with the liquid heat transfer medium 30th is floodable. Close to the ground 51 , but at a given distance from the ground 51 , there is a baffle plate 53 . This can be done with the opposite side walls 52 be structurally connected. The baffle 53 extends in particular above and in an imaginary extension of the inlet 11 . Above the baffle 53 is a bracket 22nd for the or for the test items 20th intended. In the present embodiment are on the opposite side walls 52 multiple fasteners 25th provided by means of which the bracket 22nd adjustable in height, but on the side walls 52 can be arranged fixable.

The bracket 22nd in the present case has two struts which can be arranged horizontally or in any way with regard to their inclination 23 , 24 on, which is between the opposing fasteners 25th extend. On or on the struts 23 , 24 is the test item 20th or it is the test items 20th by means of separate fastening elements 26th , as in 5 shown, fixable and attachable. In other words, the wall-side fastening device is by means of the holder 25th and with individual fastening elements of the test item 20th in that of the liquid heat transfer medium 30th floodable area 15th the test chamber 10 fixable and immovable.

The baffle 53 has one opposite the inlet 11 horizontally offset through opening 55 on. In this way it can be achieved that, for example, a surge over the inlet 11 from below into the test tank 50 inflowing heat transfer medium 30th not directly on the test item (s) 20th splashes or the test item (s) 20th only partially wetted. The baffle 53 causes, so to speak, a fluid-technical shielding of the test item (s) 20th opposite the inlet 11 .

That, for example, like a surge over the inlet 11 supplied liquid heat transfer medium 30th bounces off the floor 51 facing underside of the baffle plate 53 and is distributed homogeneously over the floor 51 . Due to the laterally offset to the inlet 11 provided through opening 55 can the liquid heat transfer medium continuously in the interior of the test tank 30th increase until it reaches the level of overflow 54 reached. Excess or continuously supplied liquid heat transfer medium 30th can then quasi in the test tub 50 circulate and continuously over the overflow 54 and the flow connected to it 12 from the test tank 50 flow away.

As in 4th shown, the baffle plate 53 also two surface sections 53a , 53b have, which are aligned to each other, or which are slightly inclined relative to the horizontal. In the present exemplary embodiment, the ends of the surface sections facing away from one another are 53a , 53b each with the opposite side walls 53 the test tank 50 connected. Facing each other and the opposite side walls 52 the surface sections can be turned away 53a , 53b rise at least slightly from the horizontal. In this way it can be achieved that when the level of the liquid heat transfer medium falls 30th the entire heat transfer medium, for example, via the passage opening 55 can drain.

The baffle 53 is also at a predetermined distance from the rear wall 56 arranged. In particular, it can also be directed towards the rear, that is to say towards the rear wall 56 or be designed to be inclined downwards to the front or front wall, not shown, so that, for example, via the inlet 11 draining heat transfer medium 30th completely from the interior of the test tank 50 can drain.

As from a comparison of the 4th and 6th shows, the bracket can 22nd height adjustable in the interior of the tub 50 be arranged.

The back wall 56 can also be double-walled. Inwardly offset to the rear wall 56 can for example be a duct wall 58 be arranged so between the rear wall 56 and the canal wall 58 a flow channel 57 for the gaseous heat transfer medium 40 can be provided. The canal wall 58 can extend continuously from the left to the right side wall 52 extend. The canal wall 58 is above a slot or free space from the floor 51 the test tank 50 Cut. As in particular in 4th shown, the lower end of the duct wall 58 above the baffle 53 end up.

In recirculation mode or if the test chamber 10 exclusively with the gaseous heat transfer medium 40 is filled, can via the flow channel 57 a directed flow or circulation of the gaseous heat transfer medium 40 respectively. As also in 9 shown, borders the rear wall 56 the test tank 50 directly to an inner wall of the rear wall 13th the test chamber 10 on. In other exemplary embodiments, it is also conceivable that the rear wall 56 the test tank 50 forming a flow channel 17th spaced from the inside of the rear wall 13th is arranged.

As also in 9 shown, borders the canal wall 58 up to an upper duct wall 59 at a predetermined inclination relative to the vertical and / or relative to the horizontal to the inside of the ceiling 14a extends. The upper canal wall 59 can especially be used as an extension of the duct wall 58 to be viewed as. The canal wall 58 and / or the upper duct wall 59 may have a width that corresponds to the distance between the opposite side walls 52 the test tank 50 corresponds.

In that of the canal wall 58 , the upper canal wall 59 and the ceiling 14a or the back wall 13th limited space of the test chamber 10 is also on the ceiling 14a a blower 72 arranged, which is designed in particular to air over the flow channel 57 suck in and over one near the ceiling 14a arranged ventilation opening 76 in the upper canal wall 59 in the interior of the test chamber 10 or the test tank 50 to promote, like this with the flow arrow 40 in 9 is indicated. One or more slats can be arranged in the area of the ventilation opening in order to direct the air flow in a required direction.

In the ceiling 14a is also another through opening 36 provided through which a rod 34 a float arrangement 32 is passed through. At a lower part of the pole 34 which are in the floodable area 50 the test tank 50 protruding are one or more floats 38 arranged. As soon as the test tub 50 with the liquid heat transfer medium 30th is flooded, cause the floats 38 an upward lifting of the bar 34 , hence the entire float arrangement 32 . This can also be combined with an in 8th indicated sensor 44 , for example, be coupled to a level sensor so that when the level of the liquid heat transfer medium increases 30th an automatic shutdown of a fluid-conveying pump beyond a permissible maximum 70 can be done.

As also in the 1 , 7th and 8th shown, the test chamber is located 10 , relative to the vertical, above the buffer storage 60 . In particular is the floor 14th the test chamber 10 above the buffer tank 60 on the support frame 3 the testing device 1 arranged. For flooding the sub-area 15th or the test tank 50 is a fluid-conveying pump 70 provided on the one hand with an outlet 62 of the buffer memory 60 and on the other hand with the influx 11 the test chamber 10 or the test tank 50 is in flow connection. By activating the fluid supplying pump 70 can the liquid heat transfer medium from the buffer storage 60 into the test tank 50 be initiated. Typically the test tub 50 from below, i.e. from the bottom, with the liquid heat transfer medium 30th acted upon or flooded.

The overflow 54 flows into the drain 12 . The sequence 12 again stands with an inlet 61 of the buffer memory 60 in flow connection. In this way, excess liquid heat transfer medium can 30th from the test tank 50 back into the buffer tank 60 be directed.

In the buffer tank 60 the liquid heat transfer medium can be located 30th be brought to a specified target temperature before a test cycle is carried out. The buffer storage 60 at least one heat exchanger 65 on that with a thermal reservoir 68 and / or with a heating or cooling machine 5 is thermally coupled. In the case of the heat reservoir or the cold reservoir 68 it can for example be a cold water source by means of which the heat exchanger 65 can be acted upon. Depending on the design of the heating and / or cooling machine 5 and depending on the requirements of the test cycle to be carried out, the liquid heat transfer medium 30th within the buffer memory 60 be heated or cooled to a specified temperature level.

Typically the liquid heat transfer medium 30th a liquid cooled to a comparatively low temperature level, for example ice water. The heat transfer medium can for example also be provided with an anti-freeze additive. Furthermore, the liquid heat transfer medium 30th Corrosion additives, such as sodium chloride, may be added, for example to improve the corrosion resistance of the test item (s) 20th to be able to test.

During a test cycle, especially during the test tub 50 with the liquid heat transfer medium 30th is flooded, a continuous circulation of the heat transfer medium can 30th respectively. The fluid-conveying pump 70 can with or after reaching the maximum fill level of the test tank 50 operated continuously or throttled, so that a steady inflow of liquid heat transfer medium 30th into the test tank 50 he follows. Excess liquid heat transfer medium is stored in the buffer tank 60 returned. There it can possibly be in the test tank 50 Slightly heating or thermally modified liquid heat transfer medium 30th with the residual heat transfer medium in the buffer tank 30th mix. In particular, during the test cycle by means of the at least one heat exchanger 65 the temperature level in the buffer tank 60 located heat transfer medium 30th be kept largely constant.

For the liquid heat transfer medium, this is in the area of the test chamber 10 a temperature control or temperature change is only required as an option and possibly not required at all. In this respect, the test chamber 10 without separate heating and / or cooling elements for the liquid heat transfer medium 30th be designed.

As also in the 7th and 8th shown, the buffer memory 60 another inlet 66 on, which by means of one or more valves 63 , 64 with the influx 11 the test chamber 10 is fluidly connectable. With the valve closed 63 and open valve 64 can by means of the activated pump 70 a circulation of the in the buffer tank 60 located liquid heat transfer medium 30th be realized even if the test chamber 10 or the test tank 50 especially not with liquid heat transfer medium 30th is applied.

Furthermore, when the pump is deactivated, for example 70 and by opening both valves 63 , 64 a drain in the test tank 50 located liquid heat transfer medium via the inlet 11 into the inlet 66 respectively. In this way, the test tub 50 can also be emptied solely under the action of gravity. For emptying the test tank 50 Alternatively, the pump can also be used 70 can be switched to a flow mode or the flow direction of the pump 70 can be inverted so that it is in the test tub 50 located liquid heat transfer medium 30th also active from the test tub 50 can pump out.

The buffer storage 60 and / or the test chamber 10 can with a number of sensors 41 , 42 , 43 , 44 , 45 , 46 be equipped. The sensors 44 can be designed as level sensors, for example. They are typically connected to the controller in terms of signaling 2 connected. Using the sensors 44 is the level of the liquid heat transfer medium 30th in the buffer memory 60 and / or in the test chamber 10 determinable. If the fill level is too high or too low, the control can switch off the test process and / or the fluid-conveying pump 70 initiate.

The sensor 41 can for example be designed as a conductance measuring device. Using the sensor 41 can for example be the salt content or the conductivity of the liquid heat transfer medium 30th tested or measured quantitatively. With the sensors 42 , 43 , 46 it can be temperature sensors. These can be designed as control sensors to measure the temperature in the area of the buffer tank 60 and / or inside the test chamber 10 to keep at a predetermined level. The sensor 42 can be designed as a control sensor for the temperature. The sensor 42 is particularly signaling with the control 2 connected to those in the test chamber 10 and / or in the buffer tank 60 to measure the prevailing temperature and accordingly the heating and / or cooling device 75 or the heat exchanger 65 or the heater or the chiller 5 to control or regulate.

The sensors 43 and 46 can be designed as overtemperature protection or as undertemperature protection. The temperature should be in the area of the test chamber 10 or in the area of the buffer memory 60 Falling below or exceeding a specified maximum permissible temperature level can be achieved by means of the corresponding sensors 43 , 46 an emergency or limit switch-off of the test device 1 respectively.

The sub-area 15th in which the test items 20th in the interior of the test chamber 10 can be arranged is typically with multiple sensors 45 provided or corresponding sensors are directly on the test item 20th arranged. The sensors 45 are used to measure electrical functions of the test object, for example 20th during the in the test chamber 10 running test cycle.

To that extent, finally, an in 10 presented procedure is provided. Here is a first step 100 at least one examinee 20th in the test chamber 10 arranged. The examinee 20th is typically connected by cable to a test unit or to an electronic evaluation. Then we open the door 8th the testing device 1 closed and the sub-area 15th the test chamber 10 will be in the next step 102 alternating with the liquid heat transfer medium 30th or with the gaseous heat transfer medium 40 applied. So can the sub-area 15th for example initially with the gaseous heat transfer medium 40 at one temperature T1 applied, which is typically well above room temperature.

The temperature level T1 can be in the test chamber for a predetermined period of time t1 10 be maintained. It is also conceivable that the temperature level is changed in a targeted manner during the period t1, following a specified test protocol. A thermal shock test is then to be carried out in particular, according to which the sub-area 15th the test chamber 10 with the liquid heat transfer medium 30th is flooded, which is a temperature T2 having. The temperature T2 is typically less than temperature T1 . It is typically less than room temperature. This can be so-called ice water, which has a temperature in the range of ± 5 ° C, for example.

Over a period of time t2, the liquid heat transfer medium 30th in the test tank 50 linger. Should that be in the test tub 50 heat transfer medium located during the period t2 can be slightly heated by continuous or controllable control of the fluid-conveying pump 70 Another liquid heat transfer medium that has been cooled or tempered beforehand to a predetermined temperature level 30th in the test chamber 10 or in the test tank 50 be initiated.

The one with the test device shown here 1 The test cycle to be carried out provides at least one change in the heat transfer medium 30th , 40 inside the test chamber 10 in front. For example, the gaseous heat transfer medium can first 40 followed by the liquid heat transfer medium 30th are introduced into the test chamber. The entire test cycle or the test process can then be ended. However, it is also conceivable to have several alternating applications of gaseous and liquid heat transfer medium 30th , 40 in the area of the test chamber 10 to be provided.

List of reference symbols

1

Testing device

2

control

3

Support frame

4th

Supply air valve

5

Heating or cooling machine

6th

Exhaust valve

8th

door

10

Test chamber

11

Intake

12

procedure

13

Back wall

14th

ground

15th

Section

16

Side wall

17th

Flow channel

18th

execution

19th

Recess

20th

Test item

22nd

bracket

23

strut

24

strut

25th

Fastening device

26th

Fastener

30th

Heat transfer medium

32

Float arrangement

34

pole

36

Through opening

38

Floats

40

Heat transfer medium

41

sensor

42

sensor

43

sensor

44

sensor

45

sensor

46

sensor

50

Test tub

51

ground

51a, 51b

Floor section

52

Side wall

53

Baffle plate

53a, 53b

Area segment

54

Overflow

54a

admission

55

Through opening

56

Back wall

57

Flow channel

58

Canal wall

59

upper canal wall

60

Buffer storage

61

inlet

62

Outlet

63

Valve

64

Valve

65

Heat exchanger

66

inlet

68

reservoir

70

pump

72

fan

75

Heating and / or cooling device

76

Ventilation opening

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 2743675 A1 [0002]

Claims (15)

Test device (1) with: - a test chamber (10) in which at least one test item (20) can be arranged, - At least a partial area (15) of the test chamber (10) can be acted upon with either a liquid heat transfer medium (30) or a gaseous heat transfer medium (40) in order to heat or cool the immediate vicinity of the test object (20) according to predeterminable test cycles. Test device according to Claim 1 , wherein the test chamber (10) has at least one inlet (11) and at least one outlet (12) for the liquid heat transfer medium (30). Test device according to Claim 1 or 2 and furthermore with a holder (22) arranged within the test chamber (10), by means of which the at least one test object (20) can be arranged in a stationary manner in the sub-area (15). Test device according to one of the preceding claims, further comprising a test tub (50) which is arranged in the test chamber (10) and can be filled with the liquid heat transfer medium (30). Test device according to Claim 2 and 4th , wherein the test tub (50) has a base (51) into which the inlet (11) opens. Test device according to Claim 5 A baffle plate (53) for the liquid heat transfer medium (30) flowing into the test tub (50) is arranged above the base (51) and at a predetermined distance from the base (51) in an imaginary extension of the inlet (11). Test device according to Claim 2 and 4th or after one of the Claims 5 or 6th , wherein the test tub (50) has at least one side wall (52) with an overflow (54), the overflow (54) being in flow connection with the drain (12). Test device according to one of the preceding Claims 2 to 7th , further with a buffer basin (60) designed to receive the liquid heat transfer medium (30), which is arranged outside the test chamber (10) and which can be fluidically coupled at least to the inlet (11), with at least one heat exchanger in the buffer basin (60) (65) is arranged to control the temperature of the liquid heat transfer medium (30). Test device according to Claim 8 , wherein the buffer basin (60) can be fluidically coupled to the drain (12). Test device according to Claim 8 or 9 , wherein the buffer basin (60) and the test chamber (10) are arranged at different height levels with respect to a vertical. Test device according to one of the preceding Claims 8 to 10 wherein the test chamber (10) is arranged above the buffer basin (60) and wherein a fluid-conveying pump (70) is arranged between an outlet (62) of the buffer basin (60) and the inlet (11). Test device according to one of the preceding Claims 8 to 11 , the buffer basin (60) having an inlet (66) which can be fluidically coupled to the inlet (11) of the test chamber (10) by means of at least one valve (63, 64). Test device according to one of the preceding claims, wherein at least one side wall (16, 56) adjoining the partial area (15) of the test chamber (10) has a flow channel (17, 57) which can be acted upon by the gaseous heat transfer medium (40) and which by means of a fan ( 72) and a heating and / or cooling device (75) can be acted upon by the gaseous heat exchanger medium (40), which is heated to a predetermined temperature. Test device according to one of the preceding claims, further with a controller (2) and with at least one sensor (41, 42, 43, 44, 45, 46) which is connected to the controller (2) in a signal-transmitting manner and wherein the controller (2) designed to optionally act on the sub-area (15) of the test chamber (10) with the liquid heat transfer medium (30) or the gaseous heat transfer medium (40). Method for thermal testing of at least one test object (20) by means of a testing device (1) according to one of the preceding claims, comprising the following steps: - Arranging the at least one test item (20) in the test chamber (10), - alternating exposure of at least a partial area (15) of the test chamber (10) with the liquid heat transfer medium (30) and with the gaseous heat transfer medium (40).

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