Protective cover for a test adapter

Abstract

Cover (1) for covering a test adapter (3) for circuit boards, with an electric drive (2) for opening and closing the cover (1) on the test adapter (3), wherein a control of the electric drive (2) is provided for controlling the speed of the cover, and the control includes at least two different limit values ​​for triggering a movement stop of the cover (1).

Description

[0001] The present invention relates to a cover for covering a test adapter for circuit boards.

[0002] Circuit board test adapters are used to test the functionality of components on the circuit board and to check the connections. For this purpose, the test adapters have contact elements in the form of needles or thin metal pins, which make contact with the points on the circuit board to be tested. Using the characteristic protective covers, often with the aid of spacers that press against the board, the circuit board is pressed down onto the test adapter from above. When the cover is in the closed position, it is usually further secured against the board by a vacuum or a suitable mechanical device. The size and weight of the protective covers vary depending on the test adapter, but they can weigh from a few kilograms to ten kilograms or more.Typically, in the prior art, protective covers are attached to the test adapter using simple hinges or cam discs. DE102012207515A1 discloses the attachment of a protective cover to the test adapter using cam discs whose radius varies to ensure precise positioning of the cover in the open and closed positions, as well as in the positions in between. With this prior art cover, the movement of the cover between the open and closed positions is manual; that is, the cover is opened and closed by hand. DE 10 2104 208 341 A1 describes a mechanism by which the protective cover is attached to the test adapter in such a way that, when the cover is closed, the rotational movement of the cover, which is rotatably mounted on the test adapter, transitions into a linear movement shortly before reaching the closed position.This linear movement allows the test contact pins and the hold-down pins to be inserted completely perpendicularly (linearly) into the spaces between or onto the components of the circuit board under test.

[0003] To increase automation and, for example, enable robots to operate the cover, solutions for the automatic operation of such covers have already been considered in the prior art, as for example in DE 20 2018 102 653 U1. Here, a force-limiting device detects whether the cover encounters resistance, such as a finger, arm, or the like, and is then stopped or even reopened upon positive detection.

[0004] A disadvantage of this technology is that it does not offer the same level of safety and flexibility as, for example, mixed operation. Mixed operation here refers to various operating modes, ranging from purely manual operation to semi-automatic operation and fully automated operation.

[0005] The object of the present invention is therefore to provide a protective cover for covering a test adapter for circuit boards, which offers a high degree of safety and flexibility.

[0006] The above problem is solved by a cover according to claim 1. The cover according to the invention for covering a test adapter for circuit boards comprises an electric drive for opening and closing the cover on the test adapter, wherein a control of the electric drive is provided for controlling the speed of the cover, and the control includes at least two different limit values ​​for triggering a movement stop of the cover. The at least two different limit values ​​make it possible to define and monitor areas with different force limits for the movement of the cover, thus ensuring a high degree of safety and flexibility.

[0007] Advantageously, the at least two limit values ​​lie on at least one envelope for triggering a movement stop of the cover. The use of envelopes allows for precise control of the cover's movement and stopping in emergencies. The at least one envelope can include a lower envelope, and the control system can be designed such that the cover's movement stops when the value falls below this envelope. Additionally or alternatively, the at least one envelope can include an upper envelope, and the control system can be designed such that the cover's movement stops when the value exceeds this upper envelope.

[0008] Advantageously, at least one envelope curve represents the current for driving the electric drive as a function of the distance traveled by the cover. Additionally or alternatively, at least one envelope curve advantageously represents the speed of the cover as a function of the distance traveled by the cover.

[0009] Advantageously, at least one envelope represents different areas in which the electric drive controls the cover at different speeds.

[0010] Advantageously, at least one envelope represents relative values ​​in relation to a reference curve, along which the control of the electric drive controls the speed of the cover.

[0011] Advantageously, the reference curve is based on at least one reference run of the cover.

[0012] Advantageously, the stopping of the cover's movement marks the beginning of a safety cycle for the cover.

[0013] Advantageously, the movement stop of the cover is an immediate stop of the cover.

[0014] Advantageously, the cover has at least one sensor for measuring a parameter to control the speed of the cover.

[0015] Advantageously, at least one sensor is a sensor for measuring the rotational speed of the cover.

[0016] Advantageously, at least one sensor is a sensor for measuring the current for the electric drive.

[0017] Advantageously, the control system can be switched between different operating modes.

[0018] Advantageously, the operating modes include at least one fully automatic mode and one purely manual operating mode.

[0019] The present invention will be explained in more detail below with reference to an exemplary embodiment and to the accompanying figures, in which Fig. Figure 1 shows a schematic side view of a cover according to the invention in the open position, Fig. 2 a schematic side view of the in Fig. The cover shown in 1 is in an intermediate position. Fig. 3 the ones in the Fig. 1 and Fig. 2 schematically represents the cover according to the invention in the closed position, and Fig. Figure 4 shows a current-displacement diagram of an exemplary reference curve and two exemplary envelopes for control.

[0020] Fig. Figure 1 shows a schematic side view (from the right) of a cover 1 according to the invention for covering a test adapter 3 for a circuit board 6 in the open position. The test adapter 3 comprises a base plate on which the circuit board(s) to be tested are placed. The cover 1, which is rotatably mounted on the rear of the test adapter 3 or its base plate, serves to cover and hold down a circuit board 6 to be tested. Fig. Figure 1 shows a bearing unit 4 by which a rear side of the cover 1 is rotatably mounted on the test adapter 3, and a locking element 5 by which a corresponding fastening element 7 on the front side of the cover 1 is locked on the test adapter 3 in the closed state, wherein the locking element 5 is at least partially recessed in the base plate of the test adapter 3.

[0021] Fig. Figure 2 shows a schematic side view of the cover 1 on the test adapter 3 in an intermediate position between the open and closed positions, and Fig. Figure 3 shows a schematic side view of the cover 1 on the test adapter 3 in the closed position. In versions for force generation by vacuum, the connection between the cover 1 and the test adapter 3 is generally as airtight as possible in the closed position, so that a vacuum can be generated inside the cover 1 to pull the cover 1 onto the circuit board 6 to be tested, which is located on the test adapter 3 or its base plate. It should be emphasized that the term "circuit board" is intended to refer to any board, regardless of its components, that can be tested by a suitable test adapter 3. The invention is not limited to a specific type or shape of circuit board or test adapter 3 to be tested.

[0022] The front side of test adapter 3 is in Fig. 1, Fig. 2 and Fig. 3 on the left side of the figure, and the rear side of test adapter 3 is in the Fig. 1 is arranged on the right side. In the schematic side view shown, the bearing unit 4 is arranged on the rear side of the test adapter 3 and the locking element 5 on the front side of the test adapter 3 (each on its base plate). In one embodiment of the test adapter 3 shown, two bearing units 4 and two locking elements 5 can also be arranged on the base plate, namely in pairs on the left and right sides of the base plate, so that the cover 1 is securely attached and guided on the test adapter 3 on both its rear and front sides.

[0023] The bearing unit 4 and the locking element 5 have guide grooves (not shown) or other suitable guide elements that enable a corresponding rotational movement of the cover 1 between the open and closed states. The arrangement and geometry of the guide grooves or elements determine the precise movement sequence of the cover 1, such that the cover 1 performs a rotational movement from the open state and, shortly before reaching the closed state, a linear movement, i.e., a linear vertical movement with respect to the base plate of the test adapter 3.

[0024] At the end of the rotational movement during the transition from the open position of the cover 1 to the closed position, the fastening element 7 on the front of the cover 1 enters the guide groove of the locking element 5 and, in conjunction with the guide grooves and elements of the bearing unit 4 and the locking element 5 of the test adapter 3, ensures that the cover 1 performs a linear movement with respect to the base plate of the test adapter 3 shortly before reaching the closed state.

[0025] A handle 8 is arranged on the cover 1. This handle 8 is located on the front of the cover 1 and is operated manually by a user to open and close the cover 1. The handle 8 can be rigidly attached to the cover 1. As shown in the Fig. 1, Fig. 2 and Fig. As shown schematically in Figure 3, the handle 8 can alternatively be pivotably attached to the cover 1.

[0026] The cover 1 according to the invention comprises an electric drive 2 which causes the automatic, i.e., non-manual, opening and closing of the cover 1 with respect to the test adapter 3. In the illustrated example, the electric drive 2 is an electric motor.

[0027] In the example shown for the cover 1, the electric drive 2 is implemented by an electric motor with a drive unit (not shown, which is, for example, an integrated gearbox). The drive unit is rotatably mounted on the cover 1 at one end by means of a bearing shaft, and rotatably mounted on the test adapter 3 at the other end by means of a bearing shaft. The positions of the bearing shafts are chosen such that a first rotational movement of the drive unit moves the cover 1 into the closed position ( Fig. 3) moves, while the opposite rotary motion of the drive unit moves the cover 1 into the open position ( Fig. 1) moves. It should be emphasized at this point that other electric drives can also be used as electric drive 2 instead of the electric motor shown. For example, an electric drive 2 can also be used that is attached to the test adapter 3 and moves the cover between the open and closed positions. Other implementations are also possible.

[0028] In one embodiment of the cover 1 according to the invention, a control unit for the electric drive 2 is provided to control the speed of the cover 1. The control unit includes at least two different limit values ​​for triggering a stop of the cover 1's movement. When the cover 1 moves from the open position to the closed position, and the closing resistance increases due to the cover 1 encountering an obstacle, such as a robot arm or an operator's hand, the electric drive 2 requires more power and thus a higher current, which causes internal limit values ​​to be exceeded. As soon as a certain preset limit value is exceeded, the cover 1 stops automatically and may even move back a short distance or completely to the open position. This provides a safety function by preventing arms, hands, or robot parts from being trapped.The control unit for the electric drive 2 can be part of the electric drive 2, or it can be located externally. In the latter case, the control unit can, for example, be located on the cover 1 or on the test adapter 3, or it can be located externally to the cover 1 and test adapter 3.

[0029] According to the invention, the control system of the electric drive 2 comprises at least two different limit values ​​for triggering a movement stop of the cover 1. These at least two different limit values ​​can, for example, be located on one envelope for triggering a movement stop of the cover (1), or on two different envelopes for triggering a movement stop of the cover (1). In other words, a number of such limit values ​​form one or both envelopes. Fig. Figure 4 schematically shows an example of a reference curve R for the movement of the cover 1 from the open position (far left in the Fig. 4) into the closed position (far right in the Fig. 4) The reference curve R is in Fig. Figure 4 is plotted in a diagram that shows the current I for controlling the electric drive 2 as a function of the distance S traveled by the cover 1. Generally, for efficiency reasons, the cover 1 should be closed as quickly as possible. In principle, the cover 1 can travel at a relatively high speed after the start and during the closing process, since an operator is only likely to bump into it during this time and not suffer serious injury. However, the risk of injury is higher at the end of the closing process, as crushing can occur between the cover 1 and the test adapter 3. Therefore, the speed of the cover 1 should be reduced in this area.

[0030] The open position of cover 1 (far left in the Fig. 4) corresponds to S=0. The reference curve R represents the current I required to move the cover 1 from the open to the closed position. If problems occur, for example, if the cover 1 encounters an obstacle, slows down, or speeds up for any reason, the current required to control the electric drive 2 changes, and the limits defined in the lower envelope A are either undershot or the limits defined in the upper envelope B are exceeded. As soon as one of these cases is detected by the control of the electric drive 2, a movement stop of the cover 1 is triggered. This movement stop of the cover 1 can be the start of a safety cycle in which the cover 1 is moved back completely or partially to the open position.Alternatively, the movement stop of the cover 1 can also be, for example, an immediate and pure stopping of the cover 1, without further movement.

[0031] The envelopes A and B can, for example, represent relative values ​​with respect to the reference curve R. These relative values ​​can be percentages or similar. The envelopes can also be calculated from a combination of a fixed or constant value and a relative value. After defining the reference curve R, the values ​​of the envelopes A and B are then simply determined based on these previously defined relative values ​​or a defined calculation procedure. These relative values ​​can vary in different regions of the current / displacement diagram (current I and displacement S), as shown in Fig. Figure 4 illustrates this. In other words, the envelope curves A and B have different distances to the reference curve R in different areas. The reference curve R is based, for example, on one or more reference runs of the cover 1.

[0032] The cover 1 according to the invention can further comprise one or more sensors for measuring a parameter for controlling the speed of the cover 1. The sensor can be a sensor (e.g., an internal or external rotary angle sensor) for measuring the rotational speed of the cover 1. The rotational angle of the cover 1 corresponds to the distance it travels. Alternatively or additionally, the sensor can be a sensor for measuring the current for the drive of the electric drive 2. In principle, a current sensor should react faster to forced disturbances, such as an obstruction of the cover 1 by an obstacle, than a rotary angle sensor. However, there may be situations in which the rotary angle sensor reacts faster. Therefore, providing both a current sensor and a rotary angle sensor can be advantageous.

[0033] As in Fig. As shown in Figure 4, the current / displacement diagram comprises several distinct regions in which the electric drive 2 controls the cover 1 at different or varying speeds. In the first region, I, the control system initiates the movement of the cover 1 from the open position at a low, gradually increasing speed. This means that the current I for controlling the electric drive 2 increases slowly. Once the cover 1 has moved a short distance from the open to the closed position, it continues moving in the second region, II, at a relatively constant (and comparatively high) speed. Therefore, in this region, II, the current I for controlling the electric drive 2 is approximately constant. The transition from the second region, II, to the third region, III, marks the point where the rotary bearing 7 in the front part of the cover 1 engages the test adapter 3 or its base plate.At this point, the closing of the cover 1 begins, and its speed decreases continuously. Meanwhile, the current I required to move the cover 1 increases due to the necessary pressure of the cover 1 against the test adapter 3 (and against the spring contact pins provided for testing the circuit board). At the end of section IV, the cover 1 is in the closed position; it no longer moves, and the current I controlling the electric drive 2 slowly decreases to zero. As in . Fig.As can be seen in Figure 4, the distance between the two envelopes A and B and the reference curve R is approximately constant, except in region III. In this region, the risk of crushing between the cover 1 and the test adapter 3 is greatly increased just before the closed position, so that even small increases in current I must cause the cover 1 to stop moving. Accordingly, in this region, envelope B is relatively close to the reference curve R.

[0034] It should also be emphasized that the control unit 2 of the electric drive 2 can switch the movement of the cover 1 between different operating modes. These operating modes include, for example, a fully automatic mode, a semi-automatic mode, and / or a purely manual operating mode. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102012207515A1

[0002] DE 10 2104 208 341 A1

[0002] DE 20 2018 102 653 U1

[0003]

Claims

[1] Cover (1) for covering a test adapter (3) for circuit boards, with an electric drive (2) for opening and closing the cover (1) on the test adapter (3), wherein a control of the electric drive (2) is provided for controlling the speed of the cover, and the control includes at least two different limit values ​​for triggering a movement stop of the cover (1). [2] Cover (1) according to claim 1, wherein the at least two limit values ​​lie on at least one envelope (A or B) to trigger a movement stop of the cover (1). [3] Cover (1) according to claim 2, wherein the at least one envelope (A or B) comprises a lower envelope (A), and the control is designed such that the movement of the cover is stopped when the envelope is undershot. [4] Cover (1) according to claim 3, wherein the at least one envelope (A or B) comprises an upper envelope (B), and the control is designed such that the movement of the cover is stopped when the upper envelope is exceeded. [5] Cover (1) according to one of claims 2 to 4, wherein the at least one envelope (A or B) represents the current for the drive of the electric drive as a function of the distance traveled by the cover. [6] Cover (1) according to any one of claims 2 to 5, wherein the at least one envelope represents the speed of the cover as a function of the distance traveled by the cover. [7] Cover (1) according to one of claims 2 to 6, wherein the at least one envelope (A or B) represents different areas in which the electric drive controls the cover at different speeds. [8] Cover (1) according to any one of claims 2 to 7, wherein the at least one envelope represents relative values ​​with respect to a reference curve along which the control of the electric drive (2) controls the speed of the cover. [9] Cover (1) according to claim 8, wherein the reference curve is based on at least one reference run of the cover. [10] Cover (1) according to any one of claims 1 to 9, wherein the stop of movement of the cover (1) is the beginning of a safety movement of the cover. [11] Cover (1) according to any one of claims 1 to 9, wherein the movement stop of the cover (1) is an immediate stopping of the cover. [12] Cover (1) according to any one of claims 1 to 11, further comprising at least one sensor for measuring a parameter for controlling the speed of the cover. [13] Cover (1) according to claim 12, wherein the at least one sensor is a sensor for measuring the rotational angular velocity of the cover. [14] Cover (1) according to claim 12 or 13, wherein the at least one sensor is a sensor for measuring the current for the drive of the electric drive. [15] Cover (1) according to one of claims 1 to 14, wherein the control is switchable between different operating modes. [16] Cover (1) according to claim 15, wherein the operating modes include at least one fully automatic mode and one purely manual operating mode.

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