Apparatus for supporting a workpiece comprising a plurality of parallel-oriented, individually longitudinally movable support pins

Abstract

In a device (1) comprising a frame (5) and a support field (2) comprising end faces (3) of a plurality of support pins (4) guided within the frame (5) parallel to one another in a main extension direction (6) and each capable of pressing against the frame (5) against a restoring force, a detection device (23) has an optical switch (18) for detecting the relative movement of the plurality of support pins (4) with respect to the frame (5). The light source (19) and the optical sensor of the optical switch (18) face each other across the main extension direction (6) of the plurality of support pins (4). The light source (19) is divided into a plurality of partial light sources (19a-19l) along one side of the support field (2), and the optical sensor (20) is divided into a plurality of partial sensors (20a-20l) along the other side of the support field (2) opposite to the side.

Description

[Technical Field]

[0001] The present invention relates to an apparatus for supporting workpieces, which comprises a plurality of parallel-oriented, individually longitudinally movable support pins. The workpieces supported by such an apparatus can be placed on the support pins or clamped by the support pins to the same or another type of apparatus. The apparatus can therefore be used as so-called form clamping jaws. In conjunction with the same or another type of apparatus, the apparatus is also suitable for gripping, i.e., for forming grips that are specifically adapted or already adapted to the respective workpiece.

[0002] In particular, the present invention relates to an apparatus for supporting a workpiece, comprising a frame, a support field consisting of end faces of a plurality of support pins guided in the frame parallel to one another in the main extension direction and each capable of being pressed against the frame against a restoring force, and a detection device having an optical switch for detecting the relative movement of the plurality of support pins with respect to the frame. [Background technology]

[0003] A holding device for workpieces is known from DE 10 05 04 199 A1, which device has a fixing device for fixing a support pin to a frame. Behind the support pin, facing away from the workpiece, an open pressure space is provided, which can be pressurized by compressed air, which support The pressure chamber can be opened by a microswitch positioned at the rear of the support plate defining the pressure chamber, and the pressure medium can flow out of the pressure chamber towards the respective workpiece through the free space between the pins. The support pins can have a radial step in the pressure chamber, which allows the pressure medium to press the support pin towards the workpiece. To detect the relative position of the workpiece with respect to the frame by one of the support pins, a microswitch is positioned at the rear of the support plate defining the pressure chamber, and the microswitch is positioned at the rear of the support pin. Stepped partA retaining rod is threaded through the retaining plate onto the body of the support pin, forming a microswitch. A radial collar at the free end of the retaining rod operates the microswitch when the support pin is pressed against the frame by a certain amount. A displacement sensor can be provided instead of the microswitch, and detects the exact position of the support pin relative to the frame.

[0004] Patent document 2 discloses a handling device for grasping, holding, moving and handling arbitrarily shaped objects, which device has the features of the preamble of independent claim 1. The handling device essentially consists of a number of holding pins that are lowered into the object to be detected and are longitudinally movably supported in holes in a holding pin guide plate, thereby clamping the object. The object is released again by pushing the holding pins back together with the injector plate. An optical switch is attached to the holding pin guide plate, which outputs a signal as soon as the holding pin is displaced longitudinally relative to the holding pin guide plate by the object and its upper end reaches the light path.

[0005] Patent Document 3 discloses a device for flexibly gripping an object with a sensor. The sensor has a plurality of holding pins for contacting and gripping the object. The holding pins are longitudinally movably supported on a support plate. The holding pins engage with a sensor array, which optically encodes and detects the relative movement of the holding pins with respect to the support plate. A hollow cylinder with a through-hole is arranged at the rear end of each holding pin, and light is axially introduced into the hollow cylinder using a light guide. The outer periphery of the hollow cylinder is opposed to the end of another light guide, so that light is introduced from the hollow cylinder into various combinations of the other light guides at various longitudinal positions of each holding pin and its associated hollow cylinder. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] DE 19802320 [Patent Document 2] German Patent Application Publication No. 4339102 [Patent Document 3] U.S. Patent No. 5,608,206 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem underlying the present invention is to disclose an apparatus for supporting workpieces comprising the features of the preamble of independent claim 1, which is adapted to provide a simple yet sufficient monitoring of the functioning of the apparatus so that it can be integrated into fully automatic production plants where complete monitoring and recording of the products is possible. [Means for solving the problem]

[0008] This problem is solved by an apparatus for supporting a workpiece, which comprises the features of the independent claim 1. Preferred embodiments of the invention are defined in the dependent claims.

[0009] In the device of the present invention, which comprises a frame and a support field consisting of end faces of a plurality of support pins guided in the frame parallel to one another in a main extension direction and each of which can be pressed against the frame against a restoring force, the detection device has an optical switch for detecting the relative movement of the plurality of support pins with respect to the frame. The light source and the optical sensor of the optical switch face each other in the main extension direction of the plurality of support pins. The light source is divided into a plurality of partial light sources along one side of the support field and / or the optical sensor is divided into a plurality of partial sensors along the other side of the support field opposite to said side.

[0010] A suitable arrangement of the light source and the light sensor in and relative to the main direction of extension allows the optical switch to determine whether at least some, preferably all, of the support pins are pressed against the frame. For this purpose, an arrangement of the light source and the light sensor is particularly suitable in which the unpressed support pins are not in the optical path of the optical switch between the light source and the light sensor, but enter this optical path by pressing the support pins, thereby blocking the light coming from the light source in front of the light sensor.

[0011] It has been found to be advantageous for the detection device of the device of the present invention to detect the relative decrease in light intensity relative to the maximum intensity actually recorded by the light sensor of the optical switch when there is nothing in the light path between the light source and the light sensor. This means that it is not just the presence or absence of any or a specific minimum decrease in light intensity that is detected. The relative decrease in light intensity indicates to what extent the light path between the light source and the light sensor is blocked, and thus how many of the multiple support pins are pressed against the frame and / or by how far relative to the frame.

[0012] Whether a particular relative decrease indicates normal or erroneous functioning of the device depends on the actual use of the device. If the device actually supports a workpiece, for example, and the support pins are partially pressed against the frame to process the surface of the workpiece, a particular relative decrease in the light intensity recorded by the optical sensor indicates normal functioning. In contrast, if the support pins are unloaded so that they should return to the frame by a restoring force, each recorded decrease in light intensity indicates an error. It is understood that a recorded decrease in light intensity is not necessarily due to the support pins being pressed. This could also be due to impurities entering the area of ​​the optical switch. However, this would also be considered an error in the device of the present invention.

[0013] The light source of the device of the present invention is divided into a plurality of partial light sources along one side of the support field, and / or DeviceThe light sensor is divided into a plurality of partial sensors along the other side of the support field opposite to the side, so that the detected light intensity of the light of the individual partial light sources or the partial intensities detected by the individual partial sensors can spatially delimit the support pins pressed against the frame. In the most favorable case, it is possible to determine which support pins in the support field are involved. In particular, in this embodiment of the device of the invention, a linear array of partial light sources can be used on one side and a linear array of partial sensors can be used on the other side of the support field, which can be obtained using commercially available, inexpensive optical sensors. Optical switch It is available as part of

[0014] It is understood that if the light source is divided into multiple partial light sources along multiple adjacent sides of the support field and the light sensor is divided into multiple partial sensors along multiple other sides of the support field that are opposite to the multiple sides, it is possible to detect more accurately where and which support pins are pressed against the frame.

[0015] Specifically, for each column and possibly each row of support pins in the support field: Optical switch Partial light sources and partial sensors can be assigned.

[0016] Alternatively or additionally, the light source can be divided into a plurality of partial light sources in the main extension direction of the support pin, and / or the light sensor can be divided into a plurality of partial sensors in the main extension direction of the support pin. In this case, it is possible to determine the distance at which the plurality of support pins are pressed against the frame. Optical switch can be elucidated more accurately.

[0017] Multiple partial light sources OverallIn order to obtain maximum information about the position of each support pin relative to the frame by the optical switch with a light source including the light source, the detection device can activate the partial light sources individually and detect the light intensities recorded by the individual partial sensors for the individually activated partial light sources separately from each other. From the recorded light intensity patterns, the corresponding pressing pattern of the support pin can be estimated via a table of empirical values, or at least it can be determined whether the pressing pattern of the support pin that should actually exist actually exists.

[0018] Typically, the device of the present invention has a fixing device that allows the support pins to be fixed relative to the frame, thereby fixing a specific pressing pattern of the support pins. The detection device of the device of the present invention preferably activates an optical switch at least when the fixing device is deactivated and the support pins are returned by their return force. In this case, the optical switch detects whether this return of the support pins has actually taken place or whether individual support pins have not been returned, which indicates an error.

[0019] In a specific embodiment of the device of the invention, the support pin can be sunk with its end opposite the end face into a chamber that can be pressurized by a pressure medium. In this case, the detection device is configured to specifically activate the optical switch when the chamber is pressurized by the pressure medium and any locking device that may be present is inactive. In this operating state, not only does the pressure medium exert a restoring force on the support pin, but any impurities between the support pins are also blown out of the pressure chamber and out of the free space between the support pins by the pressure medium. The optical path of the optical switch is correspondingly opened. If there is still a decrease in the light intensity registered by the optical sensor, this identifies an error.

[0020] In the apparatus of the present invention, the detection device preferably provides an autonomous error indication of the light intensity recorded by the light sensor of the optical switch. AboutFor example, the controller of the detection device may be programmed to evaluate the error and, if an error indication is present, output an error signal. It is further preferred that the detection device uses the error signal to indicate possible causes of the error and / or measures to correct the error, thereby providing valuable guidance to the user of the device. In automated production plants, the error signal from the detection device of the device of the present invention can be used to shut down the production plant to avoid erroneous production.

[0021] Advantageous developments of the invention emerge from the claims, the description and the drawings.

[0022] The advantages of the features and combinations of features described in the specification are merely examples and may act alternatively or cumulatively, and these advantages need not necessarily be achieved by embodiments of the present invention.

[0023] With respect to the disclosure (but not the scope of protection) of the original application and patent, the following applies: Further features can be seen from the drawings, in particular from the illustrated geometric shapes and relative dimensions of the various components to one another, as well as their relative positioning and operative connection. Combinations of features of the various embodiments of the invention or of the various claims are likewise possible and proposed here, even if they differ from the selected reference relationships of the claims. This also applies to features shown in separate drawings or mentioned in the description of the drawings. These features can also be combined with features of different claims. Similarly, features listed in claims can be omitted for further embodiments of the invention. However, this does not apply to independent claims of the granted patent.

[0024] Features listed in the claims and the description should be understood as being exactly that number or as being present in greater numbers, without the need to explicitly use the adverb "at least" in relation to their number. Thus, for example, when referring to a support field consisting of the end faces of a plurality of support pins, this should be understood as meaning that there is exactly one such support field, two such support fields, or more such support fields. Features listed in the claims may be supplemented by other features or may each be the only feature possessed by the product.

[0025] Any reference signs included in the claims do not limit the scope of the subject matter protected by the claims, and are used solely for the purpose of facilitating the understanding of the claims.

[0026] The invention will be further explained and described below on the basis of preferred embodiments shown in the drawings. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a schematic cross-sectional view of an apparatus of the present invention for supporting a workpiece; [Figure 2] FIG. 2 is a plan view of the support field of the device of FIG. 1; [Figure 3] 2 is a diagram showing the arrangement of partial light sources of a light source and partial sensors of an optical sensor of an optical switch of the device according to FIG. 1 in the first embodiment. FIG. [Figure 4] 1. FIG. 6 is a diagram showing the arrangement of partial light sources of the light source and partial sensors of the optical sensor of the optical switch of the device according to FIG. 1 in the second embodiment. [Figure 5] 10A and 10B are diagrams showing further arrangements of partial light sources of a light source and partial sensors of a light sensor of a further device of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0028] The device 1 shown in FIG. 1 is used to support a workpiece (not shown). To support the workpiece, the device 1 has a support field 2 consisting of end faces 3 of a number of support pins 4. The support pins 4 are surrounded by a frame 5 over part of their length and guided parallel to one another in their main extension direction 6. In the main extension direction 6, the support pins 4 can be pressed against the frame 5 against a restoring force. The restoring force is primarily provided by a compression spring 7 arranged on a retaining rod 8. The retaining rod 8 is threaded through a retaining plate 9 into the rear end 10 of the body 22 of the support pin 4. The compression spring 7 is supported on the end 10 on one side and on the retaining plate 9 on the other. The head 11, with its expanded diameter, of the retaining rod 8 abuts against the rear side of the retaining plate 9 and secures the support pin 4 to the retaining plate 9. A chamber 12 is formed between the end 10 of the body 22 and the retaining plate 9. The chamber 12 can be pressurized with compressed air 13 from a compressed air source 14, which exerts an additional restoring force on the support pins 4 (or replaces the compression springs 7) and blows out impurities from the free space between the support pins 4, which have a circular cross section. The support pins 4 can be fixed to the frame 5 by means of a fixing device 15. The fixing device 15 here has a screw drive 16 which biases a compression plate 17, which laterally abuts the body 22 of the support pin 4 of the support field 2, against the rest of the frame 5.

[0029] The arrangement of the fixing device 15 and the support pins 4 whose end faces 3 form the support field 2 can also be seen from the plan view of Figure 2, where the support pins 4 are shown arranged in square packs in this embodiment of the device 1, although hexagonal packs are also possible.

[0030] To monitor the function of the device 1, the device includes a detection device 23 equipped with an optical switch 18. The optical switch 18 has a light source 19 and an optical sensor 20, which are opposite each other in the main extension direction 6 of the support pin 4. The optical switch 18 is positioned in the main extension direction 6 so that its retaining rod 8 does not enter the optical path 21 between the light source 19 and the optical sensor 20 of the optical switch 18 when the support pin 4 is fully returned, as shown in FIG. 1 . This allows the optical switch 18 to monitor whether the support pin 4 is still unpressed or has already been fully returned. If only one of the support pins 4, with its retaining rod 8, enters the optical path 21, the light intensity recorded by the optical sensor 20 will be lower than the maximum light intensity when the optical path 21 is clear. If such a decrease in light intensity occurs when the support pin 4 is supposed to be returned, this indicates an error in the device 1. This error is recognized by a controller 24 of the detection device 23, which then outputs an error signal 25. The controller 24 also detects whether the fixation device 15 and compressed air source 14 are operating or not, or the controller operates them as intended, but this requires an actuator configuration for the fixation device 15.

[0031] 3 shows that the light source 19 of the optical switch 18 is divided into six partial light sources 19a to 19f, and the optical sensor 20 is divided into six partial sensors 20a to 20f, and each of the partial sensors 20a to 20f faces one of the partial light sources 19a to 19f via the row of support pins 14. By sequentially activating the partial light sources 19a to 19f and separately recording the light intensities with the partial sensors 20a to 20f, it is possible to locate the support pin 4 whose support rod 8 has entered the optical path 21 of the optical switch 18, or to estimate and locate the number of support pins 4 entering the optical path 21 according to their size.

[0032] This estimation can be further improved in the case of an optical switch 18 as shown in FIG. 4, where the light source 19 is divided into a total of 12 partial light sources 19a to 19l and the optical sensor 20 is divided into a total of 12 partial sensors 20a to 20l, and each of the partial light sources 19a to 19l and the partial sensors 20a to 20l is l and are opposed across each column and row of the support pins 4 of the support field 2.

[0033] 5 shows that if the light source 19 is divided into three partial light sources 19A to 19C and the optical sensor 20 is divided into three partial sensors 20A to 20C in the main extension direction 6 of the support pin 4, it is possible to effectively detect how deep the support pin 4 has been pushed in. This is because the support pin enters different partial paths 21A to 21C of the optical path 21 of the optical switch 18 depending on the depth. [Explanation of symbols]

[0034] 1 device 2. Supporting Field 3 End face 4 support pins 5 frames 6 Longitudinal Path 7 Compression Spring 8 Retaining Rod 9 Retaining Plate 10 End 11 Head 12 Chambers 13 Compressed air 14 Compressed air source 15 Fixation device 16 Screw drive unit 17 Compression Plate 18 Optical Switch 19 Light source 19a~19l Partial light source 19A~19C Partial light source 20 Optical Sensor 20a~20l Partial Sensor 20A~20C Partial Sensor 21 Light path 21A~21C Partial optical path 22 Main Unit 23 Detection Device 24 Controller 25 Error Signal

Claims

1. An apparatus (1) for supporting a workpiece, comprising: Frame (5), a support field (2) consisting of end faces (3) of a plurality of support pins (4) guided parallel to one another in the frame (5) in the main extension direction (6) and each of which can be pressed against a restoring force in the frame (5); a detection device (23) having an optical switch (18) for detecting relative movement of the plurality of support pins (4) with respect to the frame (5); a light source (19) and an optical sensor (20) of the optical switch (18) facing each other in a direction intersecting the main extension direction (6) at a position not overlapping the support field (2) with the main extension direction (6); The support pins (4) are arranged in a plurality of rows and columns in a direction parallel to the support field (2), The light source (19) includes a plurality of partial light sources (19a to 19l), The optical sensor (20) includes a plurality of partial sensors (20a to 20l) paired with each of the plurality of partial light sources (19a to 19l), The device is characterized in that some pairs of the partial light sources (19a to 19l) and the partial sensors (20a to 20l) correspond to each of the rows, and other some pairs of the partial light sources (19a to 19l) and the partial sensors (20a to 20l) correspond to each of the columns.

2. The light source (19) includes a plurality of main extension direction partial light sources (19A to 19C) arranged in the main extension direction (6), 2. The device (1) according to claim 1, characterized in that the optical sensor (20) comprises a plurality of main extension direction part sensors (20A-20C) arranged in the main extension direction (6).

3. The device (1) according to claim 2, characterized in that the detection device (23) is configured to activate the partial light sources (19a to 19l) and the main elongation direction partial light sources (19A to 19C) separately and to detect the light intensities recorded by the individual partial sensors (20a to 20l) and the main elongation direction partial sensors (20A to 20C) separately from each other.

4. 4. The device (1) according to claim 2 or 3, characterized in that the detection device (23) is configured to detect a relative decrease in the current light intensity recorded by each of the individual partial sensors (20a to 20l) and the main extension direction partial sensors (20A to 20C) of the light sensor (20) of the light switch (18) with respect to the maximum light intensity when the light path (21) between the light source (19) and the light sensor (20) is free.

5. 5. The device (1) according to any one of claims 1 to 4, characterized in that a fixing device (15) is provided by means of which the support pin (4) can be fixed relative to the frame (5).

6. 6. The device (1) according to claim 5, wherein the detection device (23) is configured to activate the optical switch (18) when the fixing device (15) is inactive.

7. a chamber (12) that can be pressurized by a pressure medium; Each of said support pins (4) is provided with a retaining rod (8), The retaining rod (8) passes through the retaining plate (9) and is screwed into the rear end (10) of the support pin (4) opposite to the end face (3), 7. Device (1) according to any one of claims 1 to 6, characterized in that the chamber (12) is formed between the rear end (10) of the support pin (4) and the retaining plate (9).

8. 8. The device (1) according to claim 7, characterized in that the detection device (23) is configured to activate the optical switch (18) when the chamber (12) is pressurized by the pressure medium.

9. 9. The device (1) according to any one of claims 1 to 8, characterized in that the detection device (23) is configured to evaluate the light intensity recorded by the light sensor (20) of the optical switch (18) for an error indication and to output an error signal (25) if an error indication is present.

10. 10. The device (1) according to claim 9, characterized in that the detection device (23) signals possible error causes and / or error elimination measures by means of the error signal (25).

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