Method for determining replacement of wear element, corresponding system and machine

Abstract

The invention relates to a method for determining the replacement of a wear element of an earthmoving machine, a corresponding system and a machine. The method comprises monitoring said worn component (1) to:-determine when the component is in a suitable replacement state (200); and-detecting whether an alarm event (100) has occurred, which alarm event is a candidate event of a loss event of the wear element (2); for each alarm event (100), the following steps are performed:-determining whether the wear component (1) is always in a replacement-suitable state (200) throughout a predetermined time window before the occurrence of the alarm event (100); and-if so, determining that the alarm event (100) is a replacement event of the wear element (2) corresponding to the alarm event (100), thereby determining that a replacement of the wear element (2) has occurred.

Description

Technical Field

[0001] The present invention relates to the field of earth-moving machines, and in particular to excavators, loaders, dredging machines and the like.

[0002] More particularly, the present invention relates to a method for determining replacement of a wear element in a wear assembly of an earth-moving machine.

[0003] The invention further relates to a system for determining the replacement of said wear element and to a corresponding earth-moving machine. Background Art

[0004] In the field of earth-moving machinery, it is necessary to monitor the condition of the various wear elements used, in particular to be able to determine when any of these elements require replacement. These wear elements are generally referred to as GET (Ground Engaging Tools), common examples of which are excavator teeth, but also adapters, front guards, side guards, wear caps, etc.

[0005] Furthermore, characterizing the soil being worked on can be useful, allowing the wear levels of various wear components to be determined due to abrasion. This characterization can, for example, allow for the cost of component consumption to be predicted, as well as for supply requirements to be estimated, thereby avoiding interruptions to operations due to a lack of spare parts. The geological characteristics of each excavation site can vary significantly.

[0006] Therefore, it is desirable to keep a record of the history of changes made during earthmoving operations. However, due to excessive workload or other reasons, the personnel responsible for the record may miss some changes, resulting in unreliable data.

[0007] To this end, it is desirable to have a system for automatically detecting when replacement of the wear element has occurred. Summary of the Invention

[0008] The object of the present invention is to provide a method for determining a replacement of the above-mentioned type, which method allows solving the above-mentioned problems.

[0009] This object is achieved by a method of the above type, wherein the method comprises:

[0010] - monitoring the wear assembly to determine over time whether the wear assembly is in a suitable state for replacement of the wear element; and

[0011] - monitoring the wear assembly to detect the occurrence of alarm events, wherein each of the alarm events is a candidate for a loss event of one of the wear elements;

[0012] For each of the alarm events, the method comprises the following steps:

[0013] - determining whether the wear component remained suitable for replacement throughout at least the entire time window preceding the occurrence of the alarm event; and

[0014] If this is the case, it is determined that the alarm event is a replacement event of the wear element corresponding to the alarm event, thereby determining that replacement of the wear element has occurred.

[0015] In the context of the present invention, a wear assembly refers to a set of elements comprising at least one wear element and a support in which the at least one wear element is fixed, and by way of non-exclusive example, the set of elements comprises an excavator bucket in which a plurality of teeth are fixed, but the invention can be applied to other types of wear elements, such as wear elements used in machines such as draglines, loaders, grapples, shovels for cable buckets and drilling rigs, among other possible examples. In this sense, an earth-moving machine can comprise several wear assemblies. The control device for carrying out the method can be the same for all wear assemblies, or can be independent for each wear assembly, or any intermediate situation in which there are several control devices, each controlling one or more wear assemblies.

[0016] Therefore, the method is based on monitoring two key points. First, the wear assembly is in a suitable state for wear element replacement (i.e., a state that allows replacement of the wear element), for example, when the machine is stopped and / or the wear element is within reach of the operator, or in a position suitable for automatic replacement by a dedicated replacement mechanism. This state will vary depending on the type of earthmoving machine and / or wear assembly, some examples of which are described below. Second, the wear element is monitored for the possibility of loss (typically, the element being dropped). Various approaches exist in the art for performing this monitoring for possible drop, such as proximity / presence sensors or optical monitoring of the element using a camera. When a possible loss is detected, it is interpreted as an alarm event, which is a candidate for a loss event. In practice, such events are currently used in the art to detect wear element loss, but this constitutes a different technical problem from the present invention. The methods for detecting this loss vary, and different technical solutions have been proposed, ranging from presence sensors to cameras. Therefore, the method of the present invention utilizes a type of information already used in the art for other purposes (for detecting the loss of a wear element) and combines it with information about the wear element's status to automatically determine whether an event initially interpreted as a possible loss is actually a replacement event. To this end, upon the occurrence of an alarm event, a check is performed to determine whether the wear element is in a state where replacement of the corresponding wear element can be performed. It should be understood that the alarm event itself is not an alarm that appears directly on the control console, nor is it a warning to the user. Rather, the term refers to an event that occurs and should be considered a candidate for a wear element loss event. Loss of a wear element typically occurs while the machine is operating (i.e., while earthmoving operations are ongoing) and is therefore not in a suitable state for replacement. Instead, when a wear element replacement is required, the wear element is positioned so that it can be replaced, for example, by stopping the machine so that the machine and the wear element are not in motion (although the engine may remain running) and placing the wear element within reach of the operator. If, upon the occurrence of an alarm event, it is verified that the wear element remains in a suitable state for replacement within a minimum period of time, the alarm event is determined to correspond to a replacement event, not a loss event. Thus, replacement is automatically detected without requiring any human to record whether the replacement has been performed. This information can then be used to automatically determine the operating parameters of the previously worn component (eg, component type, operating time, installation and replacement dates, etc.), and this data can be used for the purposes discussed above.

[0017] Based on the invention defined in the main claim, preferred embodiments have been provided, which are characterized by what is stated in the dependent claims.

[0018] Preferably, the monitoring of the wear assembly for detecting the alarm event is performed by a drop detection device comprising at least one drop sensor for each of the wear elements. By way of non-exclusive example, an accelerometer arranged inside the wear element may be provided such that when a movement having certain characteristics is detected, the movement is interpreted as a drop. For example, alternative embodiments may also be provided in which the at least one drop sensor comprises a presence sensor, such as a sensor based on detecting a magnetic field between a wear element and a support, the drop sensor being configured to detect whether the wear element corresponding to the presence sensor is moving away from the wear assembly. Likewise, other embodiments may be provided in which the drop detection device comprises a plurality of sensors, such as an accelerometer and a magnetic presence sensor.

[0019] Preferably, the wear assembly comprises a bucket, such as an excavator bucket, to which the wear element is attached, and wherein the suitable replacement state includes the bucket being in a non-moving state, which typically means that the earth-moving machine is also not in motion, although it need not be completely stopped. For example, it is conceivable that the engine remains running. In the case of an excavator bucket, the wear element typically comprises an excavator tooth, but it may also include a rack or adapter assembled between the bucket and the tooth, as well as other replaceable elements that wear for earth-moving operations. For example, guard plates may be provided between the adapter or on the sides of the bucket, or so-called wear caps may be provided on the adapter. Therefore, for the wear assembly in a bucket to be considered suitable for replacement, a necessary condition is that the bucket itself must be in a non-moving state. Various methods are contemplated for determining that the bucket is in a non-moving state. For example, motion sensors disposed in the bucket itself or in the articulated assembly of the bucket's support, by reading information related to the condition of the earth-moving machine, by an optical system (such as a camera), by motion sensors disposed on the wear element, or even a combination of these methods.

[0020] Preferably, the state suitable for replacement includes the bucket being within a predetermined angle range, so that a necessary condition for determining that the bucket is in a state suitable for replacement is that the bucket is tilted in a position that allows access to the wear element. This condition can be combined with the condition that the previous bucket is not in motion. Preferably, the predetermined angle range is between 15 degrees and 45 degrees. The angle is measured as an inclination relative to the horizontal plane of the ground. The preferred lower limit is determined based on the following situation: for a specific type of wear component and machinery, the wear element remains in the appropriate position and does not fall due to gravity. Similarly, the preferred upper limit is determined based on the difficulty that the operator may experience when replacing the element, which difficulty increases with increasing angle. In both cases, the final determination will depend on the characteristics of the machinery and the wear component.

[0021] Preferably, the predetermined time window is between 3 and 5 minutes, such that when a worn component is in a state suitable for replacement for at least 3 to 5 minutes, the alarm event is determined to correspond to replacement. A time that is too short may result in an erroneous replacement determination, while a time that is too long will mean that events that should actually be considered replacements will still be considered candidates for lost events.

[0022] The invention also relates to a system for determining replacement of a wear element in a wear assembly of an earth-moving machine, the system comprising a monitoring device for monitoring the wear assembly, the monitoring device being configured to carry out the above-described method.

[0023] The invention also relates to an earth-moving machine comprising the system for determining a replacement.

[0024] The present invention also encompasses other detailed features described in the detailed description of embodiments of the invention and shown in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Advantages and features of the present invention will become apparent from the following description in which, with reference to the accompanying drawings, a preferred embodiment of the invention is described in a non-limiting manner with respect to the scope of the main claims.

[0026] Figure 1 is a schematic diagram of a wear assembly corresponding to an excavator bucket with wear elements in the form of teeth assembled on a rack.

[0027] Figure 2 is a schematic diagram of an earth-moving machine including a wear assembly according to the present invention.

[0028] Figure 3 It is a set of graphs showing the evolution of some information used in the method of the present invention, these graphs being adjusted to the same horizontal axis representing time. DETAILED DESCRIPTION

[0029] A first embodiment of the present invention relates to Figure 2 An earth-moving machine of the type shown in FIG. 1 has a plurality of means for determining the Figure 1 and Figure 2 The system comprises a wear assembly 1 and a monitoring device configured to perform a method for determining replacement of the wear element 2 .

[0030] Specifically, the method for determining replacement of a wear element 2 in a wear assembly 1 of an earth-moving machine 3 includes inspecting the wear assembly 1 to determine over time whether the wear assembly 1 is in a suitable state 200 for replacement of the wear element 2 . Figure 3An example of this monitoring process over time is shown in the first graph, which is a simplified representation where a high level corresponds to an active state that is not suitable for replacement and a low level corresponds to an inactive state that is suitable for replacement.

[0031] Specifically, in the first embodiment, the wear assembly 1 is such as Figure 1 Consider an excavator bucket in FIG. , which has a wear element 2 attached to it. In this sense, for the bucket to be considered suitable for replacement, it must not be in motion, which also means that the machine 3 must not be in motion, although the engine may remain running. Similarly, the bucket must also be within a predetermined angle range between 15 and 45 degrees. In this first embodiment, monitoring whether the wear assembly 1 is in a suitable replacement state 200 is performed using accelerometers arranged within each wear element or in the bucket itself, but other embodiments are also foreseeable, such as using operating information from the control unit of the earth-moving machine 3 itself.

[0032] The method further comprises monitoring the wear assembly 1 to detect the occurrence of alarm events 100 , wherein each of the alarm events 100 is a candidate for a loss event of one of the wear elements 2 . Figure 3 The three lower diagrams show a simplified example of the time evolution of alarm events associated with three wear elements 2. By way of example, the alarm events are represented in the diagrams as peaks.

[0033] In a first embodiment, monitoring of the wear assembly 1 for detecting the alarm event 100 is performed by a drop detection device, with each wear element 2 having a drop sensor. Specifically, the drop sensor of each wear element 2 is a presence sensor that detects whether its corresponding wear element 2 is away from the wear assembly 1. In this example, the presence sensor is a magnetic Hall effect sensor arranged on the rack, which detects the presence of a magnetic field generated by a magnet arranged inside the corresponding tooth.

[0034] Whenever an alarm event 100 is detected, the method determines whether the wear component 1 remained in a suitable-for-replacement state 200 for at least the entire predetermined time window 300 preceding the occurrence of the alarm event 100. In this example, the predetermined time window 300 is three minutes, but other windows are possible, with a window between three and five minutes being preferred. If this is the case, the method determines that the alarm event 100 is a replacement event for the wear element 2 associated with the alarm event 100. Therefore, it is determined that replacement of the wear element 2 has occurred.

[0035] by Figure 3By way of example, the first diagram shows when a wear component 1 is in a state suitable for replacement 200, while the other diagrams correspond to the changes of the three wear components 2. These diagrams are illustrative and simplified diagrams. Figure 3 The second graph shows an alarm event 100 that is determined during a period in which the wear component 1 is in a suitable for replacement state 200 and has been in this state for more than the predetermined time window 300. Therefore, the alarm event 100 of the second graph is determined to correspond to the replacement of the wear element 2 of this graph.

[0036] exist Figure 3 In the example of the third diagram of FIG, the second wear element 2 does not exhibit any alarm event 100 and therefore no replacement is determined.

[0037] In the example of the fourth graph, a third wear element 2 exhibits an alarm event 100. However, when this event occurs, the wear element is not in a suitable state for replacement 200. This graph illustrates a possible time course corresponding to the situation where a wear element 2 is dropped while machine 3 is performing earthmoving operations. Since wear element 1 is not in a suitable state for replacement 200 within a predetermined time window 300 when alarm event 100 occurs, no replacement is determined to have occurred.

[0038] Other embodiments of the present invention share many features described in the preceding paragraphs, as shown below. Therefore, only the distinguishing elements will be described below, while the common elements refer to the description of the first embodiment.

[0039] In a second embodiment, monitoring of the wear assembly 1 for detecting an alarm event 100 is performed by means of one or more cameras and an image analysis system which allows the presence or absence of a wear element 2 to be identified.

Claims

1. A method for determining the replacement of a wear element (2) in a wear assembly (1) of an earth-moving machine (3), characterized in that The method comprises: - monitoring the wear assembly (1) to determine over time whether the wear assembly (1) is in a suitable state (200) for replacement of the wear element (2); and - monitoring the wear assembly (1) to detect the occurrence of alarm events (100), wherein each of the alarm events (100) is a candidate for a loss event of one of the wear elements (2); Wherein, for each of the alarm events (100), the method comprises the following steps: - determining whether the wear component (1) has been in the suitable replacement state (200) throughout at least a predetermined time window before the alarm event (100) occurs; and - If this is the case, it is determined that the alarm event (100) is a replacement event of the wear element (2) corresponding to the alarm event (100), thereby determining that the replacement of the wear element (2) has occurred.

2. The method according to claim 1, characterized in that Monitoring the wear assembly (1) for detecting the alarm event (100) is performed by a drop detection arrangement comprising at least one drop sensor for each of the wear elements (2).

3. The method according to claim 2, characterized in that The at least one drop sensor comprises a presence sensor configured to detect whether the wear element (2) corresponding to the presence sensor is away from the wear assembly (1).

4. The method according to claim 1, wherein Monitoring the wear assembly (1) for detecting the alarm event (100) is performed by at least one camera and an image analysis module configured to identify the presence or absence of the wear element (2).

5. The method according to any one of claims 1 to 4, characterized in that The wear assembly (1) comprises a bucket to which the wear element (2) is attached, and wherein the suitable replacement state (200) comprises a state in which the bucket is not in motion.

6. The method according to claim 5, characterized in that The suitable replacement state (200) includes the bucket being within a predetermined angle range.

7. The method according to claim 6, characterized in that The predetermined angle range is between 15 degrees and 45 degrees.

8. The method according to any one of claims 1 to 7, characterized in that The predetermined time window (300) is between 3 minutes and 5 minutes.

9. A system for determining replacement of a wear element (2) in a wear assembly (1) of an earth-moving machine (3), characterized in that The system comprises a monitoring device for monitoring the wear component (1), the monitoring device being configured to perform a method according to any one of claims 1 to 8.

10. An earth-moving machine (3) comprising a system for determining replacement according to claim 9.

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