DE102017116019A1 - Device and method for protecting a sensor device from contamination - Google Patents

Abstract

The invention relates to a sensor device (1) for monitoring components of chain drives (9, 10) with a sensor and a control unit (11), wherein the sensor device (1) has a light entrance (2) and / or light exit (2). The light entrance (2) and / or light exit (2) of the sensor device (1) is arranged in a shield (3) such that the light entrance (2) and / or light exit (2) through the walls of the shield (3) at least partially protected against contamination. Furthermore, the invention relates to a method for monitoring components of chain drives (9, 10) during operation in which an actuator is controlled to perform an action and immediately after completion of the action, a sensor detects a measurement signal.

Description

The invention relates to a sensor device for monitoring components of chain drives, which is protected during operation against contamination, and a method for ensuring the protection of the sensor device during operation against contamination

Chain drives are used in modern industrial production in a variety of applications, especially for drive and transport. A chain drive usually consists of an endlessly circulating chain and several sprockets that drive and deflect the chain. Often, the chain attachments in the form of transport elements, which are connected to the chain. In operation, the chain is subject to wear mainly due to abrasion of mutually moving parts of the chain links and friction of the chain links on the sprockets. Bearing clearance and abrasion can lead to a change in length of the chain. Because complex chain drives are being used more and more often in modern automated production, it is necessary to minimize maintenance and servicing of the machines and to avoid unplanned downtimes due to production downtime. Under certain circumstances, a synchronization with other chain drives is no longer guaranteed by the change in length of the chain drive and can therefore lead to increased maintenance up to a loss of production. In order to avoid this, chain drives and their add-on parts are continuously monitored so that maintenance work can be carried out in good time. Usually optical or inductive sensors are used, the z. B. measure the change in length of the chain. These sensors are usually in the immediate vicinity of the chain drive, where pollution can often occur. Possible are splashes of liquids, e.g. Oil, water, but also more aggressive liquids such as acids or alkalis.

Soiling in the form of particles such as dust and metal shavings can also occur. These soiling can pollute them so much, especially in the case of optical sensors, that a reproducible monitoring of the chain drive is no longer guaranteed. The sensors can give wrong results or fail completely. In this case, a comprehensive troubleshooting is necessary, which can lead to unplanned downtime of the entire production. Elaborate and costly maintenance and cleaning work follows, which can also lead to unplanned downtime.

The US 5,291,131 describes a method for monitoring the elongation of a rotating drive chain. In this method, two markers are mounted on the drive chain in the longitudinal direction of the chain, which are arranged at a distance from each other. The position of the markings is detected during operation by two inductive or optical sensors, which also have a distance from each other. The problem of possible contamination of the sensors during operation is not mentioned in this document.

The US 7,540,374 B2 describes another device for measuring the elongation of a drive chain by wear by means of two optical sensors. Although the sensors can, as can be seen from the drawings in the cited document, be fastened in a separate housing, it is not specified whether this housing protects the sensors against contamination.

All previously known sensor devices have in common that the problem of contamination of the sensors is not or not sufficiently considered. Thus, the measurement results of the sensors can be falsified and no longer be reproducible over a longer period.

It is therefore an object of the present invention to provide a sensor device which is protected from contamination in such a way that a chain and the attachments possibly connected to the chain can be monitored in terms of their functionality and their properties such that contamination in ongoing operation, the inclusion of Can not affect the measurement results by a sensor device.

The object according to the invention is achieved by a sensor device according to claim 1 and a method according to claim 10. Further embodiments of the invention for the sensor device are set forth in the subclaims.

The sensor device according to the invention comprises a sensor and a control unit. According to the invention, the sensor device further comprises a light entrance and / or a light exit. Depending on the working environment, contaminants of the most diverse types in the area of the sensor device can so strongly pollute the light entrance and / or the light exit during operation that the sensor is severely impaired in its mode of operation, up to a total failure. Such contamination can be, for example, oil and other liquid splashes, dust particles, metal chips. The light entry and / or light exit of the sensor device according to the invention is arranged in a shield such that the walls of the shield at least partially protects the light entrance and / or light exit from contamination. The shield also protects the light entry and / or light emission from mechanical stress, for example by falling parts. With this arrangement, proper operation of the sensor device is ensured over a long period of time. Frequent and possibly time-consuming and costly maintenance can be largely avoided.

The sensor is arranged such that it detects physical and / or chemical and / or geometric properties of both the chain and possibly existing attachments of the chain as measurement data. Reference values and measuring signals are stored in the control unit. Also in the control unit, measurement signals are calculated and these measurement results are evaluated. In addition, the execution of the measuring program is controlled and, if necessary, information is output. This inventive arrangement of the sensor and control unit in a component is particularly advantageous because the sensor device according to the invention, regardless of the prevailing environmental conditions is immediately operational and does not have to be laboriously adapted to the software and hardware of the respective application environment (plug'n play).

In a further advantageous embodiment of the invention, the shield comprises walls, which are mounted laterally and above the light entrance and / or light exit. These walls protect the light entry and / or light leakage from contamination and possibly mechanical stress from falling parts and / or splashes of liquids.

In a further embodiment of the invention, the shielding protecting the light entry and / or the light exit is designed to be open on at least one side or has a window permeable thereto for the incident and / or emergent light, thus ensuring unimpeded entry and / or exit of light into the sensor device. The shield encapsulates the light entry and / or the light exit and protects it against contamination and possibly mechanical stress. The window of the shield is designed in such a way that it blocks the entry of light and / or the exit of light also against mechanical stresses, e.g. protects parts, but is transparent to the light to be detected in the sensor for the measurements.

In a further embodiment of the invention, the shield of the sensor device comprises movable elements. This has the advantage that the movable elements can be positioned in front of the light entrance and / or light exit during the phases in which the sensor does not detect measured values. Before a measurement, the movable element is then moved so that the light entry and / or light exit is free and measurements can be made without hindrance.

In a particularly advantageous embodiment of the invention, the shield has an actuator. This actuator operates components attached to the sensor device when needed.

In a further embodiment of the invention, an element of the shield is movable by means of the actuator. The control unit of the sensor device can activate in this way at a certain time, the element of the shield and then close the light entrance and / or the light exit and thus protect against contamination or clean the light entrance and / or the light exit, if there is a need.

In a further embodiment of the invention, the actuator can actuate a movable element of the shield in such a way that this movable element opens and / or closes an opening of the shield. The light entry and / or the light exit of the sensor device is then completely protected against contamination. After opening of the movable element by the actuator, the sensor device is ready for use again. Elaborate cleaning of the sensor device is eliminated.

In a further embodiment of the invention, the movable element controlled by the actuator is a blind, a sectional door, a flap, a door, a sliding door or other movable element with which the screen is suitably closed and reopened by the actuator can be. In the open state, the path for the light incident in the sensor is free and a measurement can be carried out. When closed, the sensor device is not ready for use and protected from contamination. Elaborate cleaning work is not necessary by this advantageous arrangement.

In a particularly advantageous embodiment of the invention, the movable element of the shield, which is controlled by the actuator, a windshield wiper. The light entrance and / or the light exit or the previously arranged for the incident and / or falling light permeable window is cleaned in case of contamination by particular liquids through the windscreen wiper. Manual cost-intensive cleaning of the sensor device can be avoided.

In another embodiment of the invention, the movable element of the shield, which is controlled by the actuator, is a blower. The light entry and / or the light exit or the window arranged in front of it and permeable to the incident and / or outgoing light is cleaned by the blower in the event of contamination by liquids (eg oil), particles such as dust, chips. Costly cleaning of the sensor device can be avoided in this way or can be carried out at greater time intervals than without the presence of such an arrangement.

The method by which components of chain drives are monitored during operation comprises the following method steps: driving an actuator by the control of the sensor device, carrying out a first action by the actuator, driving a sensor by the control of the sensor device and detecting a measurement signal through the sensor. The actuator is activated in the first method step by the control of the sensor device and closes or opens or cleans the light entrance and / or the light exit or the previously arranged for the incident and / or outgoing light permeable window in the second process step. In the third method step, a sensor is activated by the control unit of the sensor device. In the fourth method step, a measurement signal from the chain drive or its components is detected by the sensor. This measurement signal is detected immediately after completion of the action of the actuator. In this way, it is ensured that the measurement signal is detected precisely when the light entrance and / or the light exit or the window arranged therebetween for the incident and / or outgoing light clears of contamination and thus the measurement signal is not impaired or inaccurate or in case of heavy pollution can not be recorded at all.

In a further advantageous embodiment of the invention, the method by which constituents of chain drives are monitored during operation is performed several times in succession. In this way, the components of chain drives are constantly monitored. Any occurring wear can be detected at any time, and the measurement signals of the sensor are reproducible.

In a further advantageous embodiment of the invention, the method by which components of chain drives are monitored during operation is controlled such that between two successive executions of the first actions by the actuator a pause of at least 5 s, preferably 1 min, particularly preferably 10 min is. It has been shown that wear of chain drives or their components does not occur suddenly and immediately, but continuously over a longer period. The acquisition of measurement signals at intervals of 10 minutes is completely sufficient to monitor the wear of chain drives or their components. If no measurement signals are detected, the sensor device is protected against contamination and possibly damage. The frequency of maintenance or cleaning work on the sensor device is significantly reduced in this way compared to unprotected devices, longer life of the sensor device are thus possible.

In a further embodiment of the invention, the method by which constituents of chain drives are monitored during operation is designed such that there is a fixed time between the actuation of the actuator and the detection of the measurement signal. This time interval is necessary for the actuator of the movable element of the shield can fulfill its task. In the case of a windshield wiper or blower, a certain amount of time is required to clean the light entrance and / or light exit or the window arranged in front of it and permeable to the incident and / or outgoing light. In the case of a closable opening of the shield a certain time is required to open the light entrance and / or light exit.

In a further embodiment of the invention, the method by which components of chain drives are monitored during operation is carried out such that the actuator sends a signal to the control unit after completion of the execution of the first action. Once the controlled by the actuator movable element of the shield has fulfilled its task (light entrance and / or the previously arranged for the incident and / or outgoing light permeable window cleaned or closed opening of the shield open), the actuator logs on a signal the control unit that a measurement signal from the chain drive or its components can be detected.

In a further embodiment of the invention, the method by which components of chain drives are monitored during operation is designed in such a way that the sensor is activated after the signal from the actuator has been received. This sensor detects a measurement signal from the chain drive or its components.

In a further embodiment of the invention, the method by which components of chain drives are monitored during operation is designed such that the actuator performs a second action after the sensor has detected the measurement signal. The actuator puts the sensor device at rest by this second action. The closable opening of the shield is closed, wipers or blowers deactivated. The sensor device is shielded until the next detection of a measurement signal and protected against contamination and possibly damage. The need for maintenance or cleaning work at the sensor device is so significantly reduced compared to unprotected devices.

Embodiments of the sensor device according to the invention and the method according to the invention are shown schematically simplified in the drawings and are explained in more detail in the following description.

• 1 a Ein erstes Ausführungsbeispiel einer Sensorvorrichtung zur Überwachung des Zustands von Anbauteilen einer Kette mit abgeschirmten Sensor in der Vorderansicht
• 1 b Ein zweites Ausführungsbeispiel einer Sensorvorrichtung zur Überwachung des Zustands von Anbauteilen einer Kette mit abgeschirmten Sensor in der Seitenansicht
• 2 a Sensorvorrichtung zur Überwachung des Zustands von Anbauteilen einer Kette mit einer Öffnung an der Unterseite der Abschirmung im Ruhezustand
• 2 b Sensorvorrichtung zur Überwachung des Zustands von Anbauteilen einer Kette mit einer seitlichen Öffnung der Abschirmung im Messzustand
• 3 a Sensorvorrichtung zur Überwachung von Bestandteilen von Kettentrieben mit einem Scheibenwischer
• 3 b Sensorvorrichtung zur Überwachung von Bestandteilen von Kettentrieben mit einem Gebläse
• 4 Ein erstes Ausführungsbeispiel einer Sensorvorrichtung zur Überwachung von Bestandteilen von Kettentrieben mit verschließbarer Öffnung
• 5 Ein zweites Ausführungsbeispiel einer Sensorvorrichtung zur Überwachung von Bestandteilen von Kettentrieben mit verschließbarer Öffnung

Show it:

• 1 a A first embodiment of a sensor device for monitoring the state of attachments of a chain with shielded sensor in front view
• 1 b A second embodiment of a sensor device for monitoring the state of attachments of a chain with shielded sensor in the side view
• 2 a Sensor device for monitoring the condition of attachments of a chain with an opening at the bottom of the shield at rest
• 2 B Sensor device for monitoring the condition of attachments of a chain with a lateral opening of the shield in the measuring state
• 3 a Sensor device for monitoring components of chain drives with a windshield wiper
• 3 b Sensor device for monitoring components of chain drives with a blower
• 4 A first embodiment of a sensor device for monitoring components of chain drives with closable opening
• 5 A second embodiment of a sensor device for monitoring components of chain drives with closable opening

1 a shows the side view of a first embodiment. According to the present invention ( 1 a, b ) includes the sensor device 1 a light entry / exit 2 as well as the shielding 3 , Dirt of various kinds can during operation the light entry / exit 2 so dirty that the sensor is severely impaired in its operation. The shield 3 which enters the light entrance / exit 2 Protects against dirt, consists of a box around the light entry / exit 2 arranged walls ( 1 a) , The walls are suitably made of a hard, durable material such as metal or plastic. This arrangement encapsulates the light entry / exit 2 and protects it during operation against contamination from both the top and the sides. In 1 b the front view of this embodiment is shown. The shield 3 has an upwardly approximately tapered shape, while it is open at the bottom. ( 2 B) , This form of shielding 3 protects the light entry / exit 2 from pollution especially from above and from the sides. Contaminations in the form of liquids (eg oil, water splashes) can come from the shield 3 drain and be collected in suitable containers. The shield 3 may also have gutters at the lower lateral ends, similar to a gutter, which trap and divert the liquid contaminants.

The shield 3 is designed in a further embodiment such that represents an almost complete enclosure of the sensor. It only has an opening through which the incident and / or outgoing light enters and exits the light 2 can reach unhindered ( 2 a, b ). At rest ( 2 a) the opening is located at the bottom to protect the shield 3 the sensor device 1 with the light entry / exit 2 from dirt from above, from the sides and partly from below. To detect a measurement signal, the shield is 3 rotated so that the opening of the shield before the light entrance and / or exit 2 is arranged and so access of the incident and / or outgoing light in the light entrance / - exit 2 allows. Also conceivable is a rotational movement of the sensor device 1 within the shield 3 , All that is necessary is a relative movement of the sensor device 1 opposite the shield 3 to allow unimpeded access of the incident and / or outgoing light into the light entrance / exit 2 to ensure. The opening can also be a window for the incoming and / or outgoing light 4 exhibit. In this case, this window can 4 also at the top of the shield 3 to be appropriate. The protection of the light entry / exit 2 Pollution is then guaranteed as well.

The sensor device according to the invention 1 can one in the shield 3 for the incident and / or outgoing light in the light entrance / exit 2 a window permeable to it 4 exhibit ( 3 a, b ). The window 4 the shield 3 is dimensioned so that it protects the light entry / exit 2 also against mechanical stress, eg parts falling on it. Around the window 4 clean from pollution is a wiper 5 mounted so that it is the window 4 above all can cleanse of contaminants in liquid form ( 3 a) , The wiper 5 can be driven at one end by a motor and thus pivot approximately at a right angle. The wiper 5 but also in two guides on the sides or top and bottom of the window 4 guided and in this way the window 4 clean almost completely of dirt. Around the window 4 To clean it of contaminants in the form of particles, a blower is used, the air through a nozzle 6 directly over the window 4 directs ( 3 b) , This fan does not have to be in the immediate vicinity of the sensor device 1 For example, already existing compressed air systems can be used. To monitor the wear of chain drives and their components, the sensor device 1 received a measurement signal of the chain drive and its components. To do this, first the window 4 through the wiper 5 or by air over the nozzle 6 cleaned. Immediately thereafter, a measurement signal through the sensor device 1 detected. This ensures that the measurement signal is captured exactly when the window 4 is free from contamination and thus the measurement signal is not inaccurate or can not be detected at all. This process of detecting the measurement signal is carried out continuously at intervals of particularly preferably 10 minutes. Other measuring intervals can be set.

4 shows the construction of a sensor device 1 whose shielding 3 has a closable opening. In this embodiment, the opening is through a roller shutter 7 in a rail 8th is guided, opened and closed again. The controller controls to acquire a measurement signal 11 the roller shutter 7 and opens the sensor device 1 for incoming or outgoing light. The control 11 also gives the signal to acquire the measurement signal from the chain 10 or sprocket 11 , After detection of the measuring signal, the roller shutter 7 through the controller 11 closed again. Also, this process is performed continuously at intervals of more preferably 10 minutes as in the previous embodiment, other intervals are selectable. The sensor device 1 is completely protected against contamination when closed. Elaborate cleaning of the sensor device is eliminated.

In a further embodiment ( 5 ) becomes the closable opening of the shield 3 through a blind 15 closed or opened. This blind 15 is about a rotary spindle 13 and a connecting element 14 from the engine 12 in a rail 8th emotional. Also in this embodiment, the controller gives 11 the signal to acquire the measurement signal from chain 10 or sprocket 11 , First the engine gets 12 a signal to move the blind 15 and thus opens the sensor device 1 , Then there is the controller 11 a signal to the sensor device 1 , The measuring signal is recorded, and the blind 15 closes via a signal from the controller 11 again the sensor device 1 , The shield 3 can also be closed or opened by other moving elements, such as a sectional door, a flap, a door, a sliding door or other suitable components.

LIST OF REFERENCE NUMBERS

1

sensor device

2 '

Light inlet / outlet

3

shielding

4

translucent window

5

wiper

6

jet

7

shutters

8th

rail

9

Sprocket

10

Chain

11

control

12

engine

13

spindle

14

connecting member

15

louvre

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• US 5291131 [0004]
• US 7540374 B2 [0005]

Claims (17)

Sensor device (1) for monitoring components of chain drives (9, 10) comprising, • a sensor • a control unit (11) wherein the sensor device (1) has a light inlet (2) and / or light outlet (2), characterized in that Light entry (2) and / or light exit (2) of the sensor device (1) in a shield (3) is arranged, that the light entrance (2) and / or light exit (2) through the walls of the shield (3) at least partially against contamination is protected. Sensor device (1) for monitoring components of chain drives (9, 10) after Claim 1 characterized in that the shield (3) comprises walls which laterally and above the light entrance (2) and / or light exit (2) and a part of the light entrance (2) and / or light exit (2) adjacent beam path of the in the light entrance (2) and / or light exit (2) of incoming and / or outgoing light are arranged. Sensor device (1) for monitoring components of chain drives (9, 10) according to one or more of Claims 1 or 2 characterized in that the shield (3) is open on at least one side and or for the incoming and / or outgoing light permeable window (4). Sensor device (1) for monitoring components of chain drives (9, 10) according to one or more of Claims 1 to 3 characterized in that the shield (3) comprises movable elements. Sensor device (1) for monitoring components of chain drives (9, 10) according to one or more of Claims 1 to 4 characterized in that the shield (3) comprises an actuator. Sensor device (1) for monitoring components of chain drives (9, 10) according to one or more of Claims 1 to 5 characterized in that an element of the shield (3) is movable by the actuator. Sensor device (1) for monitoring components of chain drives (9, 10) after Claim 6 characterized in that an opening of the shield (3) can be closed with the element which can be closed by the actuator. Sensor device (1) for monitoring components of chain drives (9, 10) after Claim 7 characterized in that the closable by the actuator element is a blind, a sectional door, a flap, a door, a sliding door or other movable element with which the opening of the shield is closed. Sensor device (1) for monitoring components of chain drives (9, 10) after Claim 8 characterized in that the element of the shield (3) movable by the actuator is a wiper (5). Sensor device (1) for monitoring components of chain drives (9, 10) after Claim 5 characterized in that the element operated by the actuator is a fan (6). Method for monitoring components of chain drives (9, 10) during operation, comprising the following method steps: Actuation of an actuator by a control unit (11) of a sensor device (1) • Perform a first action by the actuator Actuation of a sensor by the control unit (11) of the sensor device (1) • Detecting a measurement signal by the sensor, wherein the measurement signal is carried out immediately after completion of the action of the actuator. Method for monitoring components of chain drives (9, 10) during operation Claim 11 characterized in that the method steps according to Claim 10 be performed several times in a row. Method for monitoring components of chain drives (9, 10) during operation Claim 12 characterized in that between two successive executions of the first actions by the actuator a break of at least 5 s, preferably 1 min, more preferably 10 min is. Method for monitoring components of chain drives (9, 10) during operation according to one or more of Claims 11 to 13 characterized in that between the actuation of the actuator and the detection of the measurement signal is a predetermined time. Method for monitoring components of chain drives (10) during operation according to one or more of Claims 11 to 14 characterized in that the actuator sends a signal to the control unit after completion of the execution of the first action. Method for monitoring components of chain drives (9, 10) during operation Claim 15 characterized in that the control of the sensor takes place after receipt of the signal. Method for monitoring components of chain drives (9, 10) during operation according to one or more of Claims 11 to 16 characterized in that after the detection of the measurement signal, the actuator performs a second action.

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