Chain elongation monitoring device and method for determining wear

Abstract

The invention relates to a chain elongation monitoring device having a first differential transformer, a second differential transformer and a control for recording measurement values, wherein the second differential transformer is arranged at a fixed distance from the first differential transformer, and to a method for operating the chain elongation monitoring device.

Description

Technical Field

[0001] This invention relates to a chain elongation monitoring device, which has a first differential transformer, a second differential transformer, and controls for recording measured values, and also relates to a method for operating the chain elongation monitoring device. Background Technology

[0002] Chain drives are used for transmission or motion transfer in a variety of industrial applications. Multi-strand chains are typically used. In addition to the typical infinite loop chain, a complete chain drive includes multiple sprockets for deflecting the chain, and transmission or motion elements connected to and actuated by the chain. The chain wears during operation due to wear on the parts of the chain links that can move relative to each other. Other factors, such as elongation, stretching, bearing clearance, and bearing wear during the chain break-in period, can also cause chain elongation and ultimately lead to drive unit failure. Other factors affecting chain wear include the forces and loads acting on the chain, or external influences determined by the environment. Due to the complexity of these relationships, chain wear is unpredictable, and therefore, interruptions in operating cycles or even drive unit failures are unpredictable.

[0003] With the increasing number of fully automated machines and facilities, complex chain drive systems are being used more and more, as they are essential for modern factory automation. Due to the high investment costs of this high level of automation and global price pressures, it is necessary to minimize machine and facility downtime and completely prevent unexpected downtime.

[0004] In addition to direct economic losses, such unexpected downtime can lead to indirect problems, such as supply chain disruptions or failure to meet delivery deadlines, resulting in further economic losses. However, even minor wear can cause production failures due to synced cycles in the chain drive mechanism, necessitating manual readjustment. Because wear or elongation of the drive chain is unavoidable and cannot be reliably predicted in advance, continuous monitoring of the chain drive is essential to enable timely inspection, adjustment of synced cycles, and replacement of defective chains.

[0005] US 5,291,131 describes a suitable method for monitoring the elongation of a cyclic drive chain. In this method, two markers spaced apart longitudinally on the drive chain are arranged, the positions of which are detected during operation by two inductive or optical sensors, also arranged at a distance from each other. The chain's cyclic speed and the chain elongation between the spaced markers can be determined based on the measurements from the two sensors via a connected data detection system. This method cannot provide statements about other areas of the chain or small segments of the chain.

[0006] A similar method for monitoring wear on a drive chain is described in document EP 1 464 919 A1. Here, two markers made of magnetic material are attached to opposite sides of the chain. Two inductive sensors positioned beside the chain generate electrical signals when passing the magnetic markers. The sensors are arranged at a distance from each other on opposite sides of the drive chain, such that they are initially triggered simultaneously. The wear elongation of the chain can be determined by the positional offset of the sensors, provided that the wear elongation causes a time delay between sensor triggers. As in the above case, the chain's cycle speed and the chain elongation of the segment between the spaced markers can be determined based on the measurements from the two sensors. However, this method cannot describe other areas of the chain or small segments of the chain.

[0007] US 7,540,374 B2 describes another apparatus for measuring the wear elongation of a drive chain using two optical sensors. The first sensor detects a first link of the chain segment, and the second sensor determines the position and distance of a second link. Furthermore, the distances of multiple chain segments can be determined at two measurement locations spaced apart from each other.

[0008] Furthermore, it is known from the prior art to determine drive chain wear by measuring the force, path, or rotation angle of the chain tensioner or two rotation angle sensors on the drive and load wheels. However, chain tensioners are not always necessary, and rotation angle sensors are not always usable. Additionally, these are affected by wear or chain elongation. Moreover, these methods must be precisely matched to specific conditions, as measurements in these cases depend on the total chain length and sprocket wear. Adjustments are very time-consuming and prone to failure. Therefore, these methods are not universally applicable.

[0009] Depending on the sensors and measurement principles used, the aforementioned devices and methods, as known from the prior art, have a range of different drawbacks.

[0010] Conventional measurement systems require the transmission to be at a constant speed to accurately measure chain elongation and react to measurement failures due to irregularities in the transmission system, such as relative slippage between the drive wheel and the drive chain or wear on the sprocket.

[0011] However, a common feature of all previously known apparatuses and methods is that the elongation of the chain cannot be attributed to the elongation of individual chain segments. If elongation is detected, it means that the entire chain must always be replaced, leading to significantly higher costs. This also results in previously specified limits that must account for the singularity of chain elongation before the chain is replaced, and therefore require significantly lower limits compared to situations where the elongation of individual chain segments or even links is known. While individual apparatuses and methods have allowed for the measurement of values ​​for the elongation of chain segments, these values ​​cannot be assigned to individual chain segments observed during measurement, again necessitating a complete replacement of the chain. Summary of the Invention

[0012] Therefore, the object of this invention is to provide a chain elongation rate monitoring device that reliably and quickly detects the fault state of a monitored chain, determines the elongation rate of each individual chain segment, and allows the monitored chain to be monitored without having a minimum speed, and also allows for statistical detection of the chain elongation rate over a longer period of time. This invention also aims to provide a method for determining the elongation rate of chain segments, by which the fault state of a monitored chain can be reliably and quickly detected, the elongation rate of each individual chain segment can be determined, and the monitored chain to be monitored without having a minimum speed, and also allows for statistical detection of the chain elongation rate over a longer period of time.

[0013] This objective is achieved by the chain elongation monitoring device as described in claim 1. Other advantageous embodiments of the invention are set forth in the dependent claims.

[0014] The chain elongation monitoring device according to the invention comprises a first differential transformer and a second differential transformer. According to the invention, the two differential transformers are spaced a fixed distance apart. Each of the two differential transformers simultaneously picks up signals from different chain components of the chain to be monitored. Additionally, the chain elongation monitoring device has controls for recording measured values. The controls determine the position of the signal from the chain component and determine the position of the chain component. The distance between the two chain components is determined based on the position of the chain component. The chain elongation monitoring device according to the invention is designed in a specific manner such that the positions of the first chain component and the second chain component are determined simultaneously and continuously. Therefore, the fault condition of the monitored chain can be detected quickly and reliably, and the chain elongation can be statistically detected over a longer period of time.

[0015] In an optional embodiment of the invention, a first differential transformer and / or a second differential transformer are provided in the chain elongation monitoring device, and the differential transformers are adapted to detect measurements for determining the position of chain components independently of the speed and / or position of the chain to be monitored. In an optional embodiment, the first differential transformer and / or the second differential transformer are adapted to detect measurements for determining the position of chain components when the chain speed is 0. In other embodiments of the invention, measurements for determining the position of chain components can be detected at any time.

[0016] In another embodiment of the invention, the lengths of the first and / or second differential transformers at least correspond to the distance between the two differential transformers. The lengths of the differential transformers are specified in the direction of movement of the chain to be monitored. If the distance between the differential transformers is too small, each differential transformer will generate a magnetic field that may weaken the function of the corresponding other differential transformer. It has been found that the distance between differential transformers at least corresponding to their lengths is sufficient to eliminate this weakening.

[0017] In another embodiment of the invention, the chain elongation monitoring device has a circuit board with a control unit. The circuit board with the control unit is a standard component and is therefore inexpensive to manufacture and readily implemented in the chain elongation monitoring device.

[0018] In another advantageous embodiment of the invention, in addition to the first and second differential transformers, the chain elongation monitoring device also includes another position detection sensor. The position of another chain component is determined by the second position detection sensor.

[0019] In this development, the additional position detection sensor is based on a different technology than the two differential transformers. The position detection sensor is advantageously designed as an analog Hall sensor used as a proximity switch.

[0020] In another embodiment of the invention, the additional position detection sensor has a resolution lower than that of the two differential transformers. The position detection sensor is typically designed as an analog Hall sensor used as a proximity switch. The signal from the Hall sensor is converted into a yes / no signal via a comparator in the control unit. Therefore, the position detection sensor only detects whether a magnetic object has been guided past it.

[0021] In another embodiment of the invention, an additional position detection sensor is arranged in the direction of movement of the chain to be monitored between the first differential transformer and the second differential transformer. Therefore, the position detection sensor is advantageously also arranged within the chain length monitoring device and occupies only a small space.

[0022] In another embodiment of the invention, an additional position detection sensor is arranged directly on the circuit board. Therefore, the position detection sensor is advantageously also arranged within the chain length monitoring device and occupies only a small space.

[0023] In this invention, the distance between the position detection sensor and the differential transformer corresponds at least to the length of the differential transformer. The magnetic field generated by the differential transformer also varies. This magnetic field may weaken the function of the position detection sensor. It has been found that the distance between the position detection sensor and the differential transformer, at least corresponding to the length of the differential transformer, is sufficient to minimize such interference to the position detection sensor.

[0024] In another embodiment of the invention, the components of the chain elongation monitoring device (first differential transformer, second differential transformer, additional position detection sensor, control unit) are arranged in a housing. The housing protects the components from contaminants (such as dust or liquid), while the chain length monitoring device can be arranged as a component on the chain to be monitored.

[0025] In an alternative development of the invention, the first differential transformer and / or the second differential transformer are adapted to simultaneously detect measurements used to determine the position of chain components over the path length of the chain.

[0026] In this invention, the chain elongation monitoring device is adapted and configured to simultaneously detect measurements from a first differential transformer and / or a second differential transformer over a length range of the chain. The chain length range extends in the direction of chain movement.

[0027] In another embodiment of the invention, the length range is greater than or equal to half the length of the link, preferably greater than or equal to three-quarters of the length of the link, and particularly preferably greater than the length of the link. The length of the link is a custom standard according to standard chains conforming to British Standard (DIN 8188) or ANSI Standard (DIN 8187).

[0028] In another embodiment of the invention, the first differential transformer and / or the second differential transformer has at least two sensor elements forming the first differential transformer and / or the second differential transformer. These elements are the primary and secondary coils of the differential transformer, which are arranged along the direction of chain movement. For this purpose, the distance between the at least two sensor elements is limited to less than twice the length of a link of the chain to be monitored. The length of the link is determined according to a standard chain based on British Standard (DIN 8188) or ANSI Standard (DIN 8187).

[0029] In another embodiment of the invention, the chain elongation monitoring device has a first guide surface. The guide surface is substantially parallel to the chain to be monitored and specifically protects the differential transformer and position detection sensor from mechanical damage caused by the moving chain.

[0030] In an advantageous embodiment of the invention, the length LF of the first guide surface is greater than the length of one of the differential transformers, preferably greater than the sum of the lengths of the two differential transformers, and particularly preferably greater than three times the length of one of the two differential transformers. This ensures that the chain to be monitored extends substantially parallel to the chain elongation monitoring device in the area of ​​the chain elongation monitoring device, and that the differential transformers are at equal distances from the chain components.

[0031] In another embodiment of the invention, a first phase surface is adjacent to a first end of a first guide surface in the chain extension direction. The first phase surface is at an angle relative to the guide surface and is located in front of or behind the guide surface in the chain extension direction. The first phase surface guides the chain to be monitored in a specific manner such that it extends substantially parallel to the chain elongation monitoring device in the region of the chain elongation monitoring device.

[0032] In this invention, a second phase surface is adjacent to the second end of the first guide surface in the chain extension direction. The second phase surface has an angle relative to the guide surface and is located behind or in front of the guide surface in the chain extension direction. The second phase surface guides the chain to be monitored in a specific manner such that it extends substantially parallel to the chain elongation monitoring device in the region of the chain elongation monitoring device.

[0033] In another embodiment of the invention, the chain elongation monitoring device has a guiding element.

[0034] In this invention, the guide element is arranged on the side of the chain opposite to the first guide surface.

[0035] In another embodiment of the invention, the guiding element has a second guiding surface.

[0036] In another embodiment of the invention, the chain elongation monitoring device is divided into an upper housing portion and a lower housing portion. The upper housing portion houses the connectors and circuit board. Sensor elements are arranged in the lower housing portion, and guide surfaces are arranged on its underside. The sensor elements are arranged to extend sufficiently into the lower portion of the lower housing portion such that their upper edges remain below half the height of the lower housing portion. The lower housing portion further has fixing elements in its upper region for fastening the lower housing portion to the upper housing portion, while the lower region of the lower housing portion is used to house the sensor elements or differential transformer. Furthermore, guide surfaces are arranged on the underside of the lower housing portion. The width of the upper region of the lower housing portion is preferably equal to the width of the upper housing portion, while the width of the lower region of the lower housing portion is less than or equal to the width of the upper region of the lower housing portion.

[0037] In another embodiment of the invention, the length LF2 of the second guiding surface is greater than the length of one of the differential transformers, preferably greater than the sum of the lengths of the two differential transformers, and particularly preferably greater than three times the length of one of the two differential transformers.

[0038] This objective is also achieved by a method for determining the elongation of segments of the chain. Other advantageous embodiments of the invention are set forth in the dependent claims.

[0039] The method for determining the elongation of a chain segment according to the present invention comprises five steps: In the first step, a first signal from a first differential transformer is detected. In the second step, the position of a first chain component of the chain is determined based on the first signal. In the third step, a second signal from a second differential transformer is detected. In the fourth step, the position of a second chain component of the chain is determined based on the second signal. In the fifth step, the distance between the first chain component and the second chain component is determined.

[0040] Due to wear, the distance between chain components increases with the chain's operating time. Advantageously, the positions of the first and second chain components are determined synchronously and continuously. Therefore, the fault condition of the monitored chain can be detected quickly and reliably, and the chain elongation can be statistically detected over a longer period of time.

[0041] Differential transformers are particularly suitable for detecting measurements used to determine the position of chain components, independent of the speed and / or position of the chain to be monitored. In an alternative embodiment, the differential transformer is adapted to detect measurements used to determine the position of chain components when the chain speed is 0. In another embodiment of the invention, measurements used to determine the position of chain components can be detected at any time.

[0042] In this invention, measured values ​​from a first differential transformer and a second differential transformer are simultaneously detected within the length of the chain. The length of the chain extends in the direction of chain movement. The first and second differential transformers are configured and adapted to simultaneously detect measured values ​​within the length of the chain.

[0043] In another embodiment of the invention, the length range is greater than or equal to half the length of the link, preferably greater than or equal to three-quarters of the length of the link, and particularly preferably greater than the length of the link. The length of the link is a custom standard according to standard chains conforming to British Standard (DIN 8188) or ANSI Standard (DIN 8187).

[0044] In another embodiment of the invention, the measured value is detected by at least two sensor elements constituting the differential transformer. These elements are the primary coil and one or more secondary coils of the differential transformer, which are arranged along the direction of chain movement. For this purpose, the distance between the at least two sensor elements is limited to less than twice the length of a link of the chain to be monitored. The length of the link is determined according to a standard chain based on British Standard (DIN 8188) or ANSI Standard (DIN 8187).

[0045] In another embodiment of the invention, the first signal and the second signal are detected simultaneously. The distance between the chain components is also determined simultaneously. Furthermore, advantageously, the first and second measurements, as well as the determination of the distance between the chain components, are performed continuously. Therefore, the fault condition of the monitored chain can be detected quickly and reliably, and the chain elongation can be statistically detected over a longer period of time.

[0046] In another embodiment of the invention, the first differential transformer and the second differential transformer are positioned at a known distance from each other. The differential transformers are positioned at a defined distance corresponding to the pitch of the chain to be monitored under new conditions, or an integer multiple thereof. The distance between the two differential transformers is a parameter used to calculate the length value of the chain. The length value (e.g., the distance between chain components) is determined continuously and simultaneously.

[0047] In another embodiment of the invention, the detected chain component is a standard chain component. No additional extensions are required on the chain when using the method according to the invention, thus incurring no additional cost.

[0048] In this invention, the detected chain components are chain pins and / or sleeves. Chain components are typically chain sleeves or chain pins guided within chain sleeves. No additional components are required for using the method according to the invention.

[0049] In another embodiment of the invention, all structurally identical chain components of the chain being tested are detected as they are guided through a differential transformer. As the chain components are detected by the differential transformer, the chain components are continuously detected by determining the positions of all structurally identical standard chain components. Therefore, it is possible to specifically determine the elongation of individual chain segments. The number of segments depends on the length of the chain to be monitored. Ideally, the number of segments corresponds to the number of links in the chain to be monitored, such that each individual link is monitored with respect to its elongation.

[0050] In another embodiment of the invention, the first and second measurements are detected simultaneously.

[0051] In another embodiment of the invention, the length between a first chain component and an equivalent / structurally identical chain component directly adjacent to the first chain component is determined based on a first signal and a second signal. Because the positions of the chain components are continuously determined, it is possible to determine chain segments and their elongation rates. Chain segments can also be designed in a specific manner such that the distance between directly adjacent chain components can be determined. This makes it possible to replace individual links, especially during maintenance; it is not necessary to replace the entire chain.

[0052] In another embodiment of the invention, the position of the first chain component is determined uniquely based on a measurement detected by the first differential transformer, and / or the position of the second chain component is determined uniquely based on a measurement detected by the second differential transformer. Thus, each of the two differential transformers simultaneously determines the position of one (two in total) chain component. The distance between the two chain components is determined based on their positions. Attached Figure Description

[0053] The method for determining the elongation of chain segments according to the invention and exemplary embodiments of the chain elongation monitoring device according to the invention are schematically shown in simplified form in the accompanying drawings and explained in more detail in the following description.

[0054] In the attached diagram:

[0055] Figure 1 A chain elongation monitoring device according to the present invention is shown.

[0056] Figures 2a to 2c The functional principle of a differential transformer with magnetic chain elements is shown.

[0057] Figures 3a to 3c The functional principle of a differential transformer with conductive chain elements is shown.

[0058] Figure 4The diagram shows a top view of the differential transformer and a representation of its functional principle.

[0059] Figure 5 A schematic representation of the chain elongation monitoring device and evaluation circuit according to the present invention is shown.

[0060] Figure 6 The following describes a method for determining the elongation of a chain according to the present invention.

[0061] Figure 7 A side view of the chain elongation monitoring device according to the present invention is shown.

[0062] Figure 8a A cross-sectional view of the chain elongation monitoring device according to the present invention is shown in the longitudinal direction.

[0063] Figure 8b Another cross-sectional view is shown in the longitudinal direction of an exemplary embodiment of the chain elongation monitoring device according to the invention.

[0064] Figure 9 A side cross-sectional view of the chain elongation monitoring device according to the present invention is shown. Detailed Implementation

[0065] Figure 1 A chain elongation monitoring device 200 according to the present invention for determining the elongation rate of segments of chain 100 is shown. In this exemplary embodiment and the following exemplary embodiments, the chain 100 to be monitored is designed as a roller chain and has alternating inner portions 110 and outer portions 120 connected to each other by link pins 140 guided in chain sleeves 130. Under the new conditions of chain 100, the link pins 140 are spaced apart by a distance p0.

[0066] To determine the elongation of chain 100 during operation, the chain elongation monitoring device 200 is positioned perpendicular to the joint axis of the chain 100 to be monitored, such that under the new conditions of chain 100, the distance d between the differential transformers 210 and 220 corresponds exactly to an integer multiple of the distance p0 between two adjacent chain pins 140 of the chain 100 to be monitored. The first differential transformer 210 and the second differential transformer 220 of the chain elongation monitoring device 200 itself are arranged on a base plate 250. The differential transformers 210 and 220, together with the electrical connections, are arranged in a housing (not shown) to prevent contamination. The differential transformers 210 and 220 consist of one primary coil and two secondary coils, and therefore have three sensor elements. Thus, each of the differential transformers 210 and 220 is adapted to simultaneously record measurements over the length of the chain 100 to be monitored. The length within the length range in the chain's direction of movement is based on the length p(p0) of the link of the chain 100 to be monitored, and in this exemplary embodiment, it is p0. The detection of the measured values ​​by the two differential transformers 210 and 220 also occurs simultaneously.

[0067] Under the new conditions between sensors 210 and 220, the length L0 of chain 100 is an integer multiple of the distance p0 between two adjacent chain pins 140 (L0 = n * p0), which is seven times the distance p0 in this exemplary embodiment. The chain pins 140 located above the differential transformers 210 and 220 are a and b distances from the edges of the differential transformers 210 and 220 (the corresponding left edges in this exemplary embodiment and the following exemplary embodiments). Therefore, the chain length L0 is L0 = d - (a0 + b0) = d - 2a0 = d - 2b0, because distances a and b are the same under the new conditions of chain 100 (a0 = b0). Distances a and b are different due to the change in chain 100 length ΔL. The elongation ΔL of the chain 100 to be monitored is first determined by determining lengths a and b. The following formulas apply to the elongation ΔL of chain 100: ΔL / L0 = L - L0 / L0 = L / L0–1 and DL / Lo = (d-a+b) / (da o +b o )-1 =(bb o +aa o ) / (d+b o -a o )

[0068] Differential transformer A210 generates phase shifts Asin and Acos, while differential transformer B220 generates phase shifts Bsin and Bcos. Therefore, the following formulas apply to the distances a and b of chain 100 under actual conditions: a = arctan(Asin / Acos), b = arctan(Bsin / Bcos). Then, the elongation ΔL of chain 100 is derived from the phase shifts detected by the two differential transformers A210 and B220: ΔL / Lo = (arctan (Bsin / Bcos) - arctan (Asin / Acos)) / d.

[0069] To determine the elongation of chain 100 and its segments, a first signal is detected by a first differential transformer A210. Simultaneously, a second signal is detected by a second differential transformer B220. The position of the first chain component is then determined based on the first signal, and the position of the second chain component is determined simultaneously based on the second signal. In this exemplary embodiment, the two chain components are chain pins 140. The distance between the two chain pins 140 is then determined according to the following formula: ΔL / Lo = (arctan ( Bsin / Bcos ) −arctan ( Asin / Acos )) / d.

[0070] Advantageously, the first and second signals 2 and 4 are continuously detected, and the positions of the first and second chain components 3 and 5 are also continuously determined. The detection of 2 and 4 and the determination of 3 and 5 also occur particularly in the stationary chain 100, so a minimum speed of the chain 100 is not necessary for operating the chain elongation monitoring device 200.

[0071] exist Figures 2a to 2c The diagram shows the detection of ferromagnetic material 280 and... Figures 3a to 3cThe functional principle of differential transformers A 210 and B 220 when a conductor 290 is detected is illustrated. In this exemplary embodiment, the principle is explained based on sensor A 210; this similarly applies to the second sensor B 220. Sensor 210 has a primary coil 230 and two symmetrically arranged secondary coils 240 and 241. An alternating voltage with a constant frequency and amplitude is applied to the primary coil 230. An electromagnetic alternating field is generated via the primary coil 230, which induces corresponding opposite voltages Ucos and Usin in each of the secondary coils 240 located therein. At the same location, the voltage amplitude also varies with the distance between the object and the secondary coils 240 and 241. The secondary coils 240 and 241 are connected in series in opposite phase, so the voltages at their connection are subtracted from each other. When the two coils of sensor 210 are each symmetrically constructed, the resulting voltage is exactly zero. If the symmetry is disturbed, an output voltage is generated, the phase of which indicates the direction relative to the primary voltage, and the value of which indicates the magnitude of the asymmetry. This is achieved by forming arctan = K*Usin / K*Ucos. However, since the object disrupting the symmetry is always at the same distance from the two secondary coils in the first-order approximation, the factor K is eliminated from the equation, leaving the ratio of the induced voltages Usin / Ucos, which represents the position of the object disrupting the symmetry. Here, the symmetry of sensor 210 is disrupted by the passage of chain components 280 and 290. Ferromagnetic chain component 280 ( Figures 2a to 2c The disrupted magnetic field lines are brought closer together, amplifying the magnetic field at and around the chain component 280. When the chain component 280 is positioned at the edge of the sensor 210 within the region of the sensor 210... Figure 2a , Figure 2c That is, the asymmetry generated by the chain component 280 is greatest when it moves out of or into the sensor area. Then, when the chain component 280 is located at the left edge of the sensor 210, the sensor 210 generates the maximum output voltage U = +1 ( Figure 2a This is schematically shown on display 245, and when chain component 280 is located at the right edge of sensor 210 ( Figure 2c When the chain component 280 is located in the middle of the sensor 210, an output voltage U = -1 is generated. Figure 2b When the asymmetry generated by sensor 210 is 0, the resulting output voltage is U = 0. Conductive chain component 290 ( Figures 3a to 3c The magnetic field lines are disturbed in a specific way to further separate them, resulting in a reduction of the magnetic field at and around the chain component 280. When the chain component 290 is arranged at the edge of the sensor 210 in the region of the sensor 210 ( Figure 3a , Figure 3cThat is, the asymmetry generated by the chain component 280 is greatest when it moves out of or into the sensor area. Then, when the chain component 290 is located at the left edge of the sensor 210, the sensor 210 generates the maximum output voltage U = -1. Figure 3a This is schematically shown on display 245, and when chain component 290 is located at the right edge of sensor 210 ( Figure 3c When the chain component 290 is located in the middle of the sensor 210, an output voltage U = +1 is generated. Figure 3b When the asymmetry generated by sensor 210 is U = 0, the resulting output voltage is U = 0.

[0072] Figure 4 A top view of sensor A 210 for detecting the position of chain links is shown. The chain 100 to be monitored has alternating inner and outer portions connected to each other by link pins 140 guided in a chain sleeve. The link pins 140 are spaced apart by a distance p. Sensor 210 has a primary coil 230 and two symmetrically arranged secondary coils 240, 241. An alternating voltage with a constant frequency and amplitude is applied to the primary coil 230. An alternating electromagnetic field is generated via the primary coil 230, which induces oppositely oriented voltages Ucos and Usin in each of the secondary coils 240, 241 located therein. When no object is present, the resulting voltage is zero because the induced voltage is in the form of π and the current-carrying regions cancel each other out.

[0073] Figure 5 A top view of another exemplary embodiment of a sensor device 200 with evaluation circuits 310, 320 according to the present invention is shown. Sensors A 210, B 220 are also positioned in a specific manner such that, under the new conditions of chain 100, the distance d between sensors 210, 220 corresponds exactly to an integer multiple of the distance p0 between two adjacent chain pins 140 of the chain 100 to be monitored. As in the previous exemplary embodiment, sensors 210, 220 may be designed as differential transformers that operate inductively, used to determine the position of chain components. However, sensors 210, 220 may also be optical or magnetic sensors or combinations of sensors of the aforementioned types. Sensors 210, 220 are each connected to evaluation circuits 310, 320. Evaluation circuits 310, 320 supply the detected measurements to an A / D converter 330, where analog measurements are converted into digital values ​​for storage on a microcontroller 340.

[0074] In this exemplary embodiment, a permanent magnet 260 is arranged on the chain 100, and the position of the permanent magnet is detected by a Hall sensor 270. This embodiment is particularly useful when the chain 100 is made of a diamagnetic material, such as stainless steel. A microcontroller connected to the Hall sensor 270 records the number of times the permanent magnet 260 passes through, and thus draws conclusions about the wear rate of the chain 100. Alternatively, individual components of the chain 100 may be made of a magnetic material. The geometry of the chain 100 remains unchanged.

[0075] Figure 6 An exemplary embodiment of a method 1 for determining the elongation of a chain 100 according to the present invention is shown.

[0076] Method 1 begins by detecting a first signal 2 from the first differential transformer 210 and using this first signal to determine the position 3 of the first chain component. Simultaneously, a second signal 4 is detected by the second differential transformer B 220, and the position 5 of a second chain component with the same structure as the first chain component is determined using this second signal. The first sensor 210 and the second sensor 220 are separated by a defined distance d, which corresponds to an integer multiple of the pitch p0 of the chain 100. In the next step 6, the distance between the chain components 5 is determined based on the detected measurements and the length of the chain 100. The wear-related elongation of the chain 100 is determined by correlating the determined length of the chain 100 with its length under new conditions.

[0077] Figure 7 A side view of an exemplary embodiment of a chain elongation monitoring device 200 according to the present invention is shown, which is installed and ready to monitor the elongation ΔL of a chain 100 to be monitored. The chain 100 to be monitored is designed as a roller chain and has alternating inner portions 110 and outer portions 120 connected to each other by link pins 140 guided in a chain sleeve 130. To prevent contamination, the chain elongation monitoring device 200 has a housing 201 in which components (a first differential transformer 210, a second differential transformer 220, an additional position detection sensor 270, a control unit 340, a circuit board 320 having a first evaluation circuit 310 and a second evaluation circuit, and a base plate 250) are arranged. The housing 201 itself has an upper housing portion 202 and a lower housing portion 203, which are securely connected to each other, for example by means of clamp fasteners. The housing 201 also has a power connection 207 and a connection 208 for a data cable. The guide surface 204 is the area of ​​the chain length monitoring device 200 that is at the minimum distance from the chain 100. At opposite ends, the guide surface 204 has phase surfaces 205 and 206 that are inclined relative to the guide surface 204.

[0078] Figures 8a to 8bThe diagram shows a view of a ready-to-use chain elongation monitoring device 200 along the chain's running direction. The chain 100 to be monitored is designed as a roller chain and has alternating inner portions 110 and outer portions 120 connected to each other by link pins 140 guided in a chain sleeve 130. The chain elongation monitoring device 200 has a housing 201 in which components are arranged. A first evaluation circuit 310 and a second evaluation circuit 320 are arranged on a circuit board 209. Figure 8a The chain elongation monitoring device is divided into an upper housing portion 202 that houses the connector and circuit board 209, and a lower housing portion 203 that houses sensor elements 210, 220 and has a guide surface 204. The sensor elements 210, 220 are arranged sufficiently far into the lower region 203b of the lower housing portion 203 such that their upper edges remain below half the height of the lower housing portion 203. The lower housing portion 203 is further divided. The upper region 203a of the lower housing portion 203 includes a fastening element for securing the lower housing portion 203 to the upper housing portion 202 and has the same width as the upper housing portion 202, while the lower region 203b of the lower housing portion 203, having the guide surface 204, is formed to be narrower than either the upper housing portion 202 or the upper region 203a of the lower housing portion 203.

[0079] The chain elongation monitoring device 200 is fixed in a specific manner such that the guide surface 204 is 0.2 mm away from the chain sleeve 130 of the chain 100. In the region arranged between the side portions 120 of the chain 100, the width b of the guide surface 204... F The width b between the side portions 120 and the chain 100 is less than the width of the chain 100. K Differential transformers 210 and 220 are arranged in a specific manner close to the guide surface 204, such that they are at the minimum possible distance from the chain 100. Figure 8b ).

[0080] Figure 9A cross-sectional view of an exemplary embodiment of a chain elongation monitoring device 200 according to the present invention is shown. The chain elongation monitoring device 200 has a housing 201 in which components are arranged. A first evaluation circuit 310 and a second evaluation circuit 320 are arranged on a circuit board 209, and a position detection sensor 270 is also arranged directly on the circuit board 209 between differential transformers 210 and 220. The differential transformers 210 and 220 are arranged in a specific manner close to the guide surface 204 such that they are at the minimum possible distance from the chain 100 and are connected to the circuit board 209 via lines 211 and 221. The guide surface 204 defines the chain elongation monitoring device 200 relative to the chain 100 and has phase surfaces 205 and 208 on its end faces. The circuit board 209 is connected via lines 251 and 252 to a connection 206 for power supply and a connection 207 for data lines. The chain elongation monitoring device 200 can be fastened by means of fastening openings 255 and 256.

[0081] Explanation of reference numerals in the attached figures

[0082] 1. A method for determining the elongation of a chain.

[0083] 2. Detect the first signal from the first differential transformer.

[0084] 3. Determine the position of the first chain component

[0085] 4. Detect the second signal from the second differential transformer.

[0086] 5. Determine the position of the second chain component

[0087] 6. Determine the distance between the first chain component and the second chain component.

[0088] 100 chains

[0089] 110 inner link of the chain

[0090] 120 chain outer links

[0091] 130 chain sleeve

[0092] 140 chain pin

[0093] 200 Chain Elongation Monitoring Device

[0094] 201 housing

[0095] 202 Upper shell section

[0096] 203 Lower housing section

[0097] Upper region of the lower shell of 203a

[0098] 203b Lower shell portion, lower region

[0099] 204 guiding surface

[0100] 205 First Phase Surface

[0101] 206 Power Connection

[0102] 207 is used for connecting data cables.

[0103] 208 Second Phase Surface

[0104] 209 circuit board

[0105] 210 Differential Transformer A

[0106] 211 Installation Parts

[0107] 220 differential transformer B

[0108] 221 Installation Part

[0109] 230 primary coil

[0110] 240 secondary coil

[0111] 250 base plate

[0112] 251 power cord

[0113] 252 data cable

[0114] 255, 256 Fastening

[0115] 260 permanent magnet

[0116] 270 Hall effect sensor / position detection sensor

[0117] 275 Evaluation Circuit Magnetic Sensor

[0118] 280 ferromagnetic material

[0119] 290 non-magnetic bodies

[0120] 310 First Evaluation Circuit

[0121] 320 Second Evaluation Circuit

[0122] 330A / D converter

[0123] 340 Microcontroller / Control Unit

[0124] b K Wide chain between inner plates

[0125] b F Wide guiding surface

[0126] ΔL chain elongation

[0127] L represents the chain length between differential transformer A and differential transformer B under actual conditions.

[0128] L0 is the chain length between differential transformer A and differential transformer B under the new conditions.

[0129] P0 is the pitch (distance between two adjacent chain pins) under the new conditions.

[0130] p represents the pitch (the distance between two adjacent chain pins) under actual conditions.

[0131] d Distance of differential transformer

[0132] a is the distance from the chain pin to the edge of the differential transformer A under actual conditions.

[0133] b is the distance from the chain pin to the edge of the differential transformer B under actual conditions.

[0134] a0 is the distance from the chain pin to the edge of the differential transformer A under the new conditions.

[0135] b0 is the distance from the chain pin to the edge of the differential transformer B under the new conditions.

Claims

1. A chain elongation monitoring device (200), the chain elongation monitoring device comprising: ● First differential transformer (210), ● Second differential transformer (220), ● Controls used to record measurement values. The second differential transformer (220) is arranged at a fixed distance from the first differential transformer (210). in, The chain elongation monitoring device is adapted and configured to simultaneously detect measurements from the first differential transformer and the second differential transformer within the length range of the chain. The chain elongation monitoring device (200) has a first guide surface (204).

2. The chain elongation monitoring device (200) according to claim 1, Its features are, The lengths of the first differential transformer (210) and / or the second differential transformer (220) correspond to the distance between the first differential transformer (210) and the second differential transformer (220).

3. The chain elongation monitoring device (200) according to claim 1, Its features are, The chain elongation monitoring device (200) has a circuit board, which has a control unit (340).

4. The chain elongation monitoring device (200) according to claim 1, Its features are, In addition to the first differential transformer (210) and the second differential transformer (220), the chain elongation monitoring device (200) also has another position detection sensor (270).

5. The chain elongation monitoring device (200) according to claim 4, Its features are, The other position detection sensor (270) is based on a different technology than the first differential transformer (210) and the second differential transformer (220).

6. The chain elongation monitoring device (200) according to claim 4, Its features are, The other position detection sensor (270) has a lower resolution than the first differential transformer (210) and the second differential transformer (220).

7. The chain elongation monitoring device (200) according to claim 4, Its features are, The other position detection sensor (270) is arranged between the first differential transformer (210) and the second differential transformer (220).

8. The chain elongation monitoring device (200) according to claim 4, Its features are, The other position detection sensor (270) is directly arranged on the circuit board (209).

9. The chain elongation monitoring device (200) according to claim 3, Its features are, The components, namely the first differential transformer (210), the second differential transformer (220) and the control unit (340), are arranged in the housing (201).

10. The chain elongation monitoring device (200) according to claim 1, Its features are, The length LF of the first guide surface (204) is greater than the length of one of the first differential transformer (210) and the second differential transformer (220).

11. The chain elongation monitoring device (200) according to claim 1, Its features are, The first phase surface (205) is adjacent to the first end of the first guide surface (204) in the chain extension direction.

12. The chain elongation monitoring device (200) according to claim 11, Its features are, The second phase surface (206) is adjacent to the second end of the first guide surface (204) in the chain extension direction.

13. The chain elongation monitoring device (200) according to claim 11, Its features are, The chain elongation monitoring device (200) has a guiding element.

14. The chain elongation monitoring device (200) according to claim 13, Its features are, The guiding element is arranged opposite to the first guiding surface.

15. The chain elongation monitoring device (200) according to claim 13, Its features are, The guiding element has a second guiding surface.

16. The chain elongation monitoring device (200) according to claim 15, Its features are, The length LF2 of the second guiding surface is greater than the length of either the first differential transformer (210) or the second differential transformer (220).

17. The chain elongation monitoring device (200) according to claim 15, Its features are, The third phase surface is adjacent to the first end of the second guide surface in the chain extension direction.

18. The chain elongation monitoring device (200) according to claim 15, Its features are, The fourth phase surface is adjacent to the second end of the second guide surface in the chain extension direction.

19. The chain elongation monitoring device (200) according to claim 10, Its features are, The length LF of the first guide surface (204) is longer than the sum of the lengths of the first differential transformer (210) and the second differential transformer (220).

20. The chain elongation monitoring device (200) according to claim 10, Its features are, The length LF of the first guide surface (204) is greater than three times the length of one of the first differential transformer (210) and the second differential transformer (220).

21. The chain elongation monitoring device (200) according to claim 16, Its features are, The length LF2 of the second guiding surface is longer than the sum of the lengths of the first differential transformer (210) and the second differential transformer (220).

22. The chain elongation monitoring device (200) according to claim 16, Its features are, The length LF2 of the second guiding surface is more than three times the length of one of the first differential transformer (210) and the second differential transformer (220).

23. A method (1) for determining the elongation of a segment of a chain (100) during operation, the method comprising the steps of: ● Detect the first signal from the first differential transformer (210). ● The position of the first chain component of the chain (100) is determined based on the first signal. ● Detect the second signal from the second differential transformer (220). ● The position of the second chain component of the chain (100) is determined based on the second signal. ● Determine the distance between the first chain component and the second chain component. in, Simultaneously detect the first signal and the second signal. The chain elongation monitoring device (200) has a first guide surface (204).

24. The method (1) for determining the elongation of segments of a chain (100) during operation according to claim 23, Its features are, The first differential transformer (210) and the second differential transformer (220) have a known distance between them. The distance is a parameter used to calculate the length value of the chain (100).

25. The method (1) for determining the elongation of segments of a chain (100) during operation according to claim 23, Its features are, The chain components being tested are standard chain components.

26. The method (1) for determining the elongation of segments of a chain (100) during operation according to claim 25, Its features are, The chain components being tested are the pins (140) and / or sleeves (130) of the chain (100).

27. The method (1) for determining the elongation of segments of a chain (100) during operation according to claim 25, Its features are, The test examines all structurally identical chain components that are guided through the first differential transformer (210) and the second differential transformer (220) in the chain components being tested.

28. The method (1) for determining the elongation of segments of a chain (100) during operation according to claim 23, Its features are, The length between the first chain component and a chain component of the same type directly adjacent to the first chain component is determined based on the first signal and the second signal.

29. The method (1) for determining the elongation of segments of a chain (100) during operation according to claim 23, Its features are, The position of the first chain component is determined solely based on the first signal detected from the first differential transformer (210), and / or the position of the second chain component is determined solely based on the second signal detected from the second differential transformer (220).

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