Work Vehicle Components

Abstract

The present invention describes a work vehicle component 10 comprising: a cavity 12 having an extension axis A obtained within the component 10 and delimited by a sidewall 13; an opening 14 for the cavity 12 located on an exterior surface 11 of the component 10; a wear sensor 16 housed within the cavity 12 and having a first axial end 16c located at the opening 14 for the cavity 12; and a support body 22 inserted into the cavity 12 with a first axial end 22a aligned with the first axial end 16c of the wear sensor 16. The support body 22 is connected to and restrained by the sidewall 13 of the cavity 12, and the wear sensor 16 is physically connected to and at least axially restrained by the support body 22.

Description

[Technical field]

[0001] The present invention relates to components for work vehicles such as earth moving machines, mining machines, demolition machines, and the like. [Background technology]

[0002] These types of machines are typically mounted on a mobile structure known as an undercarriage which allows the machine to be moved over terrain which is often uneven or loose.

[0003] The undercarriage typically includes two chain assemblies arranged parallel to and spaced apart from one another and configured to receive and transmit torque to the ground.

[0004] Each chain assembly includes a number of undercarriage components that typically include a closed-loop chain over drive and idler wheels operatively connected to a tensioning unit, and further includes a number of rollers between the drive and idler wheels that are configured to guide the chain in motion and absorb loads transmitted by the machine.

[0005] A chain usually comprises a number of links, each link usually comprising a pair of plates facing each other. These links are usually interconnected by pins and bushes. Each pin is usually inserted into a hole provided on the plate and connects two links to each other. A bush is usually placed radially outside the pin to separate the plates of the link from each other and protect the pin from the outside environment, and to engage the driving and idler wheels. On the links, shoes are usually mounted, which are in direct contact with the ground and serve to project the tractive force to the ground and to increase the contact surface between the machine and the ground. The type of shoe used depends on the ground on which the machine operates, the environmental conditions in which the machine operates, and the specifications proposed by the machine manufacturer.

[0006] The undercarriage is typically subjected to extremely damaging operating conditions due to both the overall weight of the machine and the large amounts of power transmitted to the ground by the machine engine, as well as the configuration and composition of the ground on which the machine operates.

[0007] Thus, undercarriage components, like other components of work machines such as buckets, rippers, loaders, bucket tines, loader tines and ripper tines, are exposed to high mechanical stresses which can cause damage and wear to the components themselves.

[0008] Wear is one of the reasons for machine downtimes to carry out repair interventions or replacement of components of a working machine to ensure its proper operation.

[0009] The applicant has verified that by properly planning machine downtimes, the performance of the machine in terms of production can be optimized. In particular, the applicant has verified that in order to optimize the production performance of a working machine, the working machine should be stopped to carry out repair interventions or replacement of components before wear phenomena cause the machine to break down and thus force a sudden stop. At the same time, the applicant has also verified that it is not possible to predict machine downtimes for repair or replacement of components that are practically uncompromised or close to practical destruction, since optimizing the production performance of the working machine may result in an unreasonably long total machine downtime.

[0010] The applicant has noted that in order to be able to predict destruction due to excessive wear of one or more components of a work machine and to prevent having to replace or repair components that are still working properly, it would be important to be able to know the current wear state of the components, or of those components that are however most exposed to wear.

[0011] Applicant has hypothesized that it may be possible to use statistical considerations regarding the rate of component wear to predict the state of wear of work machine components by knowing the average operating life (in terms of machine operating hours) of each individual component for each type of machine and component, and for each type of machine operating condition.

[0012] However, the Applicant has established that such statistical considerations are unreliable, since there are too many variables, often interrelated, that must be taken into account in order to be able to obtain meaningful data and to be able to effectively predict the wear state of the individual components.

[0013] The applicant has therefore realised that it would be expedient to be able to have a direct measurement of the state of wear of one or more components of a work machine in order to be able to effectively predict failure and at the same time minimise the machine downtime required to ensure proper operation of the machine.

[0014] To that end, the applicant has attempted to carry out periodic inspections of the wear condition of the components via visual or instrumental checks on the components by qualified personnel.

[0015] The applicant has verified that such periodic inspections obviously require interruptions to the operation of the machine for safety reasons and therefore require machine downtime, although limited, required to carry out the inspections.

[0016] Furthermore, in the applicant's experience, it is not always possible to carry out visual or instrumental checks on components, such as undercarriage components, as such components may not be directly reachable (such as is the case for example with pins or elements inside the rollers) or they may be covered with mud, debris, etc. (which are quite often present in the typical environment in which machines operate).

[0017] Document US 2015 / 0081166 describes a system for monitoring wear on a substructure component with a sensor device having a probe configured to measure wear-related information. The probe may be a resistor having one or more resistors configured as a probe, the resistance value of which wears away in association with a change in the probe. The change in the resistance value is associated with an amount of material removed from the substructure component due to wear. The probe is placed in the vicinity of or in contact with the substructure component.

[0018] Document WO2019 / 097556 in the name of the applicant teaches the preparation of a seat on a substructure component, the seat being open towards the outside and adapted to receive a consumable transducer. The transducer assumes the presence of an electric circuit comprising a plurality of discrete elements supported by a substrate and coupled in parallel. The transducer is arranged with its ends aligned with the external surface of the substructure component, so that the transducer is subject to the same wear as that of the substructure component.

[0019] The Applicant believes that systems such as those described in U.S. Patent Application Publication Nos. 2015 / 0081166 and WO2019 / 097556 can provide an indication as to the current state of wear of an undercarriage component.

[0020] However, the applicant has found that in order to have a valid indication as to the condition of wear of a work machine component, it is necessary to ensure that the wear sensor is always substantially aligned with the surface of the component whose condition of wear is being monitored.

[0021] Accordingly, the applicant has recognised that it would be advantageous to be able to ensure consistent and substantial alignment between a wear sensor and the surface of a work machine component whose wear condition is being monitored. [Prior art documents] [Patent documents]

[0022] [Patent Document 1] US Patent Application Publication No. 2015 / 0081166 [Patent Document 2] WO2019 / 097556 [Non-patent literature]

[0023] [Non-Patent Document 1] Association Connecting Electronics Industries(IPC(1996)IPC-T-50:Terms and Definitions for Interconnecting and Packaging Electronic Circuits,Revision F(June 1996),IPC,Northbrook,IL) Summary of the Invention [Means for solving the problem]

[0024] The present invention therefore relates to a working machine component comprising a cavity obtained in the component, having an extended axis and radially delimited by at least one side wall, an opening for the cavity located on an external surface of the component, a wear sensor housed in the cavity and having a first axial end located in the opening for the cavity, and a support body inserted in the cavity with its first axial end aligned with the first axial end of the wear sensor, wherein the support body is physically connected to and at least axially constrained to the side wall of the cavity and the wear sensor is physically connected to and at least axially constrained to the support body.

[0025] A first axial end of the wear sensor, located in the opening for the cavity located in the external surface of the component, is in contact with a work surface on which the component operates (such a work surface being, for example, the ground or another component). In this way, wear of the component that removes material from the external surface of the component and thus results in an axial lowering of such external surface can be identified by the wear sensor.

[0026] Applicant has demonstrated that the force exerted by the work surface on a wear sensor (which is in contact with the work surface) can damage the wear sensor.

[0027] The applicant has realized that by providing a support body having a first axial end aligned with the axial end of the wear sensor, forces transmitted by the working surface to the wear sensor that could damage the wear sensor are blocked (at least partially) by the support body. Any possible destruction of the wear sensor can thus be anticipated. By physically connecting the support body to the side wall of the cavity, possible movement of the support body relative to the cavity can be prevented and forces applied to the support body by the working surface can also be at least partially transmitted from the support body to the component. Thus, by physically connecting the wear sensor to the support body and axially restraining the wear sensor to the support body, the wear sensor can be maintained in a predetermined position inside the cavity, in particular the first axial end of the wear sensor can be maintained at the opening for the cavity and thus at the external surface of the component.

[0028] By doing so, it can be ensured that the wear sensor is always substantially aligned with the exterior surface of the component, and therefore the current degree of wear of the component can be reliably identified.

[0029] The term "work machine component" or "component" means a component of a work machine that is subjected to loads, stresses and strains that can cause wear on the component itself. Examples of work machine components are buckets, rippers, loaders, bucket tines, loader tines, ripper tines, and undercarriage components.

[0030] The term "undercarriage component" means any of the following components: drive wheels, idler wheels, pins, bushings, links, link plates, rollers, and shoes of an undercarriage.

[0031] The cavity in the component has an axis of elongation along which the cavity is formed, which may coincide with an axis of symmetry of the cavity if the cavity is substantially cylindrical in shape.

[0032] The terms "axial", "axially", "radial" and "radially" are used with reference to the component whose condition of wear is being monitored.

[0033] Specifically, the terms "axial" and "axially" are meant as a measure / size disposed / measured or extending in a direction substantially parallel to the axis of elongation of a cavity within a component.

[0034] The terms "radial" and "radially" refer to datums / sizes disposed / measured or extending in a direction substantially perpendicular to an axis of elongation of a cavity in a component, and datums / sizes lying in a plane perpendicular to such axis of elongation.

[0035] The terms "radially inner / outer" refer to positions closer to or further from the axis of elongation of the cavity, respectively.

[0036] The terms "axially inner / outer" refer to positions closer to or further away from an opening for a cavity in a component, respectively.

[0037] The term "sensor" refers to a device that directly interacts with the system being measured, i.e., the first element in the measurement chain that converts a process variable into a measurable signal.

[0038] The term "wear" refers to the gradual loss of material from the surface of a body. When referring to a component, the term "wear" refers to the gradual loss of material from the surface of the component.

[0039] The expression "mechanical properties", when referring to a body or structure, means at least one of the following: mechanical resistance (defined as the ability to withstand static stress), elastic energy (defined as the ability to withstand dynamic stress), hardness (defined as the resistance to localized plastic deformation), and fatigue resistance (defined as the ability to withstand cyclic stress).

[0040] The present invention may include at least one of the preferred features described below.

[0041] The wear sensor is preferably also radially constrained to the support body.

[0042] The wear sensor preferably comprises a substrate and at least one electrical circuit supported by the substrate, the wear sensor comprising a measuring portion that can be configured to wear down and modify a measurable electrical characteristic of the at least one electrical circuit depending on the degree of wear.

[0043] According to this method, the axial end of the wear sensor, which is placed in the opening for the cavity, gradually loses material as the component wears. This is because, as the component wears, the external surface of the component becomes radially lower and therefore the cavity opening becomes radially lower. The lowering of the cavity opening has a tendency to expose the measuring part of the wear sensor, which is also subject to wear. The supporting body is also subject to wear and loses material as the cavity opening becomes radially lower.

[0044] The gradual loss of material from the wear sensor causes a change in a measurable electrical characteristic of an electrical circuit, such that from a reading of such electrical characteristic, the amount of material lost from the sensor can be determined.

[0045] The measurable electrical property of an electrical circuit may be, for example, electrical resistance, electrical capacity or inductance, considered individually or in combination.

[0046] The substrate serves the purpose of interconnecting various electrical components of an electrical circuit with one another, for example via conductive tracks engraved or marked on the substrate itself.

[0047] The mechanical properties of the support body are preferably different from the mechanical properties of the substrate of the wear sensor.

[0048] The wear sensor is preferably a flexible printed circuit (FPC).

[0049] A flexible printed circuit, according to the definition provided by the Association Connecting Electronics Industries (IPC (1996) IPC-T-50: Terms and Definitions for Interconnecting and Packaging Electronic Circuits, Revision F (June 1996), IPC, Northbrook, IL), is a schematic structure of printed circuits and components using a flexible base material with or without a flexible cover layer.

[0050] The flexible base material forms the substrate of the wear sensor.

[0051] Applicant has found that by constructing the wear sensor using a flexible printed circuit, any forces transmitted from the work surface to the wear sensor are immediately compensated for by deformation of the printed circuit, thereby preventing both destruction of the wear sensor and axial displacement of the entire wear sensor.

[0052] Indeed, the Applicant has recognized that by constructing a wear sensor using a flexible printed circuit, the wear sensor will bend (at a first axial end) when exposed to forces transmitted by a work surface until such forces are counteracted. While bending, the wear sensor will not lose contact with the work surface and thus will continue to perform its function. Furthermore, the curvature of the first end of the wear sensor prevents the tendency of forces transmitted by the work surface to axially displace the wear sensor relative to the support body.

[0053] Illustrative examples of materials that can be used to construct the substrate are polyimide, polyethylene naphthalate, polyethylene teraphthalate, polyethylene, polyurethane, polyester, and fluoropolymers.

[0054] The substrate is preferably in the form of a film.

[0055] The material from which the substrate of the wear sensor is constructed is preferably different from the material from which the support body is constructed.

[0056] The support body preferably extends axially over a length at least equal to the axial length of the measuring portion of the wear sensor.

[0057] In this way, the support body is able to perform its function on the wear sensor over at least the part of the sensor that is adapted to wear.

[0058] The substrate and at least one electrical circuit of the wear sensor preferably do not make direct contact with the sidewalls of the cavity.

[0059] In this way, any strain that the component imposes on the side walls of the cavity is not directly applied to the wear sensor.

[0060] Preferably, the support body has a section, taken along a given radial plane, that has an area that is greater than or equal to about 30% of the cross-sectional area of ​​the cavity on a section taken along the same given radial plane.

[0061] The support body preferably has a section, taken along a given radial plane, having an area that is greater than or equal to about 50% of the cross-sectional area of ​​the cavity on a section taken along the same given radial plane.

[0062] Preferably, the support body has a section, taken along a given radial plane, that has an area that is greater than or equal to about 75% of the cross-sectional area of ​​the cavity on a section taken along the same given radial plane.

[0063] Preferably, the support body has a section, taken along a given radial plane, that has an area that is greater than or equal to about 90% of the cross-sectional area of ​​the cavity on a section taken along the same given radial plane.

[0064] Preferably, at least a portion of the support body is interposed between the side wall of the cavity and the wear sensor.

[0065] In this way, any strain that the component imparts to the side walls of the cavity is imparted to the support body and not to the wear sensor.

[0066] Preferably, at least a portion of the support body is interposed between the side wall of the cavity and the wear sensor along the entire axial extension of the wear sensor.

[0067] It is preferred that the ratio between the resistance to localized plastic deformation of the material constituting the support body and the resistance to localized plastic deformation of the material of the component surrounding the cavity is greater than or equal to 0.15, the resistances to localized plastic deformation of the support body and the component being measured under identical test conditions using the Brinell scale, or that the ultimate tensile strength of the material constituting the support body is greater than or equal to 15% of the ultimate tensile strength of the component surrounding the cavity.

[0068] Examples of test conditions that can be used for measuring hardness according to the Brinell scale can be found in standard ISO 6506-1:2015.

[0069] The resistance of a material to concentrated plastic deformation is its hardness.

[0070] If the hardness of the support body (or component) cannot be measured on the Brinell scale using exactly the same test conditions as those for measuring the hardness of the component (or support body), or if it is not possible to accurately determine the hardness of the support body or component using the Brinell scale, it is preferable to refer to the ratio between the ultimate tensile strength of the material constituting the support body and the ultimate tensile strength of the material constituting the component in order to compare the two hardnesses.

[0071] For metallic materials the ultimate tensile strength is preferably determined according to standard ISO 6892-1:2016. For plastic or polymeric materials the ultimate tensile strength is preferably determined according to standard ISO 527-1:2019.

[0072] The applicant has determined that the edges of the openings of cavities in the component may tend to plastically deform radially towards the axis of the cavity, possibly due to forces transmitted between the component and the work surface. Such deformations tend to close the cavity openings, especially if the component has already worn to some extent. This closure or partial closure of the cavity openings may prevent the wear sensor from performing its function of losing material as the component wears.

[0073] The applicant has found that providing a support body in a cavity in which the ratio between the hardness of the material constituting the support body and the hardness of the material of the component surrounding the cavity is included in the above specified interval can make a difference to said deformation of the edge of the cavity opening.

[0074] In particular, the applicant has found that by increasing the stiffness of the support body, the radial plastic deformation of the edge of the opening is reduced.

[0075] However, the applicant has found that it may be appropriate not to exceed a certain ratio between the hardness of the support body and the hardness of the component. Indeed, the applicant has found that if the hardness of the support body is too high with respect to the hardness of the component, the support body may be exposed axially beyond the outer surface of the component (and may be exposed to less wear relative to the outer surface of the component). This may result in exposing the support body to too high a load that may destroy it.

[0076] It is preferred that the ratio between the resistance to localized plastic deformation of the material constituting the support body and the resistance to localized plastic deformation of the material of the component surrounding the cavity is greater than or equal to 0.30, the resistances to localized plastic deformation of the support body and the component being measured under identical test conditions using the Brinell scale, or that the ultimate tensile strength of the material constituting the support body is greater than or equal to 30% of the ultimate tensile strength of the component surrounding the cavity.

[0077] It is preferred that the ratio between the resistance to localized plastic deformation of the material constituting the support body and the resistance to localized plastic deformation of the material of the component surrounding the cavity is less than or equal to 1.5, the resistances to localized plastic deformation of the support body and the component being measured under identical test conditions using the Brinell scale, or that the ultimate tensile strength of the material constituting the support body is greater than or equal to 150% of the ultimate tensile strength of the component surrounding the cavity.

[0078] It is preferred that the ratio between the resistance to localized plastic deformation of the material constituting the support body and the resistance to localized plastic deformation of the material of the component surrounding the cavity is greater than or equal to 0.50, the resistances to localized plastic deformation of the support body and the component being measured under identical test conditions using the Brinell scale, or that the ultimate tensile strength of the material constituting the support body is greater than or equal to 50% of the ultimate tensile strength of the component surrounding the cavity.

[0079] It is preferred that the ratio between the resistance to localized plastic deformation of the material constituting the support body and the resistance to localized plastic deformation of the material of the component surrounding the cavity is less than or equal to 1.30, the resistances to localized plastic deformation of the support body and the component being measured under identical test conditions using the Brinell scale, or that the ultimate tensile strength of the material constituting the support body is greater than or equal to 130% of the ultimate tensile strength of the component surrounding the cavity.

[0080] It is preferred that the ratio between the resistance to localized plastic deformation of the material constituting the support body and the resistance to localized plastic deformation of the material of the component surrounding the cavity is greater than or equal to 0.75, the resistances to localized plastic deformation of the support body and the component being measured under identical test conditions using the Brinell scale, or that the ultimate tensile strength of the material constituting the support body is greater than or equal to 75% of the ultimate tensile strength of the component surrounding the cavity.

[0081] It is preferred that the ratio between the resistance to localized plastic deformation of the material constituting the support body and the resistance to localized plastic deformation of the material of the component surrounding the cavity is less than or equal to 1.10, the resistances to localized plastic deformation of the support body and the component being measured under identical test conditions using the Brinell scale, or that the ultimate tensile strength of the material constituting the support body is greater than or equal to 110% of the ultimate tensile strength of the component surrounding the cavity.

[0082] It is preferred that the ratio between the resistance to localized plastic deformation of the material constituting the support body and the resistance to localized plastic deformation of the material of the component surrounding the cavity is greater than or equal to 0.90, the resistances to localized plastic deformation of the support body and the component being measured under identical test conditions using the Brinell scale, or that the ultimate tensile strength of the material constituting the support body is greater than or equal to 90% of the ultimate tensile strength of the component surrounding the cavity.

[0083] Preferably, the ratio between the resistance to localized plastic deformation of the material constituting the support body and the resistance to localized plastic deformation of the material of the component surrounding the cavity is equal to 1, the resistances to localized plastic deformation of the support body and the component being measured under identical test conditions using the Brinell scale, or the ultimate tensile strength of the material constituting the support body is greater than or equal to 100% of the ultimate tensile strength of the component surrounding the cavity.

[0084] The support body is preferably made of metal. Examples of metals that can be used to construct the support body are steel, stainless steel, bronze, brass, cast iron, aluminum alloys. According to this method, the ratio between the hardness of the material constituting the support body and the hardness of the material of the component surrounding the cavity is within the intervals specified above.

[0085] The support body and the component are preferably made of the same material.

[0086] In some embodiments of the present invention, the support body may be made of polymeric materials such as aliphatic polyamides (such as nylon and ertalon) and aromatic polyamides (such as Kevlar).

[0087] The applicant has found that a support body made of a polymeric material is less effective than a support body made of a metallic material for preventing plastic deformation of the edge of the cavity opening, but the vibratory strain caused by a support body made of a polymeric material is not as great as that caused by a support body made of a metallic material on the wear sensor.

[0088] Indeed, the applicant has found that during normal use of the component, the support body is subjected to dynamic loads (as well as static loads) which can generate undesirable vibrations in the support body.

[0089] By providing a support body made of a polymer material, such vibrations can be damped and are not transmitted directly to the wear sensor, in this way reducing the distortion of the wear sensor and therefore the likelihood of destruction.

[0090] The applicant has also found that, regardless of the material from which the support body is constructed, the greater the degree to which the support body occupies the cavity, the less radial plastic deformation of the opening edge.

[0091] The volume of the support body is preferably equal to at least 15% of the volume of the cavity.

[0092] The volume of the support body is preferably equal to at least 30% of the volume of the cavity.

[0093] The volume of the support body is preferably at least equal to 50% of the volume of the cavity.

[0094] The volume of the support body is preferably at least equal to 75% of the volume of the cavity.

[0095] The volume of the support body is preferably at least equal to 90% of the volume of the cavity.

[0096] The volume of the support body is preferably at least equal to 95% of the volume of the cavity.

[0097] The support body is preferably restrained to the side walls of the cavity using an adhesive. An example of a glue that can be used is a two-part epoxy thixotropic glue that is heat and chemical resistant, such as the product Elantas ADH 50.50.

[0098] In this case, the support body is preferably inserted into the cavity leaving a radial gap.

[0099] The radial gap between the support body and the cavity is preferably less than 2 millimeters.

[0100] The radial gap between the support body and the cavity is preferably less than 1.5 millimeters.

[0101] The radial clearance between the support body and the cavity is preferably less than 1.0 millimeter.

[0102] The radial gap between the support body and the cavity is preferably less than 0.5 millimeters.

[0103] The radial clearance between the support body and the cavity means that the support body is radially displaced between two radially opposite positions and contacts the side wall of the cavity at each of the positions of the support body.

[0104] Alternatively, the support body is inserted into the cavity by mechanical interference, in other words, the maximum radial dimension of the support body, along at least one radial plane, is preferably greater than the minimum radial dimension of the cavity.

[0105] The mechanical interference coupling of the support body within the cavity prevents any relative movement between the support body and the cavity.

[0106] The support body preferably comprises a storage seat for the wear sensor, the wear sensor being restrained in said storage seat.

[0107] In this way, the wear sensor is not damaged during positioning of the support body in the cavity, especially if the support body is inserted into the cavity by mechanical interference.

[0108] The wear sensor is preferably embedded in the support body.

[0109] According to this method, the support body can be inserted by casting into a cavity in which the wear sensor is already positioned.

[0110] In some embodiments, the support body is made of an electrically insulating material.

[0111] Other features and advantages of the present invention will become more apparent from the following description of preferred embodiments of the invention, which proceeds with reference to the accompanying drawings. [Brief description of the drawings]

[0112] [Figure 1] 1 is a schematic perspective cross-sectional view of parts of a component of a work machine according to the present invention; [Diagram 2] FIG. 2 is an enlarged view of details of the component of FIG. 1 with some parts removed to better highlight other parts. [Diagram 3] FIG. 2 is an enlarged view of details of the component of FIG. 1 with some parts removed to better highlight other parts. [Figure 4] FIG. 2 is a schematic perspective view of some details of a component according to the invention; [Diagram 5] FIG. 2 is a schematic perspective view of some details of a component according to the invention; [Figure 6] 1 is a partial cross-sectional view of a component according to the present invention; [Figure 7] 1 is a partial cross-sectional view of a component according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0113] Referring to FIG. 1, 10 generally indicates a component according to the present invention.

[0114] The work machine component 10 shown in the accompanying figures is an undercarriage component, to which reference will be made hereinafter as an example of a work machine component. The undercarriage component 10 may be, for example, an undercarriage drive wheel, an idler wheel, a pin, a bushing, a link, a link plate, a roller or a shoe.

[0115] FIG. 6 shows an example in which the undercarriage component 10 is a shoe, while FIG. 7 shows an example in which the undercarriage component 10 is a drive wheel.

[0116] As shown in FIG. 1, the undercarriage component 10 has an exterior surface 11 intended to interact with a work surface (not shown), which may be, for example, the exterior surface of another undercarriage component or the ground.

[0117] In the example of Figure 6, the work surface is the ground over which the caterpillar moves, whereas in the example of Figure 7, the work surface is another undercarriage component, specifically a bushing of the chain.

[0118] In either case, the exterior surface 11 of the undercarriage component 10 is the surface that is monitored for wear.

[0119] In the substructure component 10, a cavity 12 is obtained (better shown in FIG. 2) delimited by a side wall 13. The cavity 12 can be obtained, for example, by boring and has a substantially cylindrical shape (as is the case in the example shown in the attached figure). In other embodiments not shown in the figures, the shape of the cavity 12 can be a straight prism with a polygonal base, an inclined prism with a polygonal base or a truncated pyramid. The cavity 12 can have a constant radial section along its axial extension or can have radial sections that differ in area or shape along its axial extension.

[0120] In either case, the cavity 12 has an opening 14 facing the exterior surface 11 that defines an inlet section for the cavity 12. The cavity 12 has an extension axis A along which the cavity itself extends. The extension axis A intersects the opening 14 and extends towards the inside of the substructure component 10 over a depth from a first axial end 12a of the cavity 12 to a second axial end 12b opposite the first 12a. In the case of a substantially cylindrical cavity (as shown in FIG. 2), the extension axis A coincides with the axis of symmetry of the cavity 12.

[0121] The cavity 12 may be blind and closed at the second axial end 12b or may have an opening 12c taken along the side 13 connected to a passage 15 in the substructure component 10 (as shown diagrammatically in the examples of Figures 1, 2 and 3). In other embodiments, the cavity 13 may also be open at the second axial end 12b (as shown in Figure 6).

[0122] The undercarriage component 10 further comprises a wear sensor 16 inserted into the cavity 12 (better shown in FIG. 4).

[0123] The wear sensor 16 is a flexible printed circuit (FPC) that includes an electrical circuit 17 that includes a number of electrical components 18, each of which has a predetermined measurable electrical characteristic.

[0124] Flexible printed circuits are constructed using photolithography techniques or by laminating copper strips about 0.1 millimeters thick between two films of flexible dielectric polymer material. These films made of polymeric materials can be made of PET or polyimide, for example. The films made of polymeric materials are coated with a heat-curing adhesive during the lamination process.

[0125] As an example, a flexible printed circuit according to the present invention having a length of 5 centimeters can be bent to make two opposing ends of the printed circuit overlap without any breaking and without any plastic deformation.

[0126] The wear sensor 16 is configured to de-sequence the electrical components 18 of the electrical circuit 17 according to the wear of the wear sensor 16 .

[0127] The electrical component 18 is placed on the measuring part 16a of the wear sensor 16. The sensing part 16b of the sensor 16 is placed axially below the measuring part 16a. The sensing part 16b comprises a coupling terminal 19 of an electrical circuit 17 adapted to be connected to a device 20 for processing or conditioning the electrical signal coming from the wear sensor 16 (schematically shown in Figs. 6 and 7). The device 20 may for example be a transducer that receives an input electrical signal from the wear sensor 16 and produces an output signal that changes when the input electrical signal changes. The device 20 may be connected to the coupling terminal 19 of the electrical circuit 17 via an electrical conductor 20a passing through the passage 15 of the substructure component (as shown diagrammatically in Fig. 1). In other embodiments (for example as shown in Fig. 6), the device 20 may be placed axially below the cavity 12. In other embodiments not shown in the figures, the device 20 may be housed inside the cavity 13.

[0128] The electrical components 18, in a preferred embodiment of the invention, are resistors connected in parallel with one another and at equal distances along the electrical circuit 17. As shown diagrammatically in Figure 3, the electrical components 18 are continuous along the axial direction and are therefore gradually and successively removed from the electrical circuit as wear of the wear sensor 16 progresses. By measuring the electrical resistance at a coupling terminal 19 of the electrical circuit 17, the number of resistors 18 still present on the wear sensor 16 can be established and therefore the axial length of the wear sensor 16 can be determined.

[0129] The wear sensor 16 further comprises a substrate 21 (FIGS. 3 and 4) upon which the electrical circuitry 17 is printed or screen printed and upon which the components 18 are disposed.

[0130] The undercarriage component 10 further comprises a support body 22 for the wear sensor 16 placed inside the cavity 12. The support body 22 is arranged inside the cavity 12 and therefore faces the wear sensor 16 at the opening 14 of the cavity 12.

[0131] The support body 22 has a first axial end 22a, a second axial end 22b opposite the first axial end 22a, and a central portion 22c extending between the first axial end 22a and the second axial end 22b.

[0132] In an embodiment of the invention, at least the portion on the support body 22 in which the cavity 12 is obtained is made of a material having mechanical properties similar to those of the substructural component 10 .

[0133] As an example, the substructure component 10 may be made of a wear-resistant steel, for example a steel with a low carbon content (comprised between 0.2% and 0.45% by weight). The ultimate tensile strength is comprised between about 1450 MPa and about 1930 MPa. The hardness is comprised between about 420 HWB 10 / 3000 and 530 HBW 10 / 3000. An example of a steel that can be used is boron steel of the MnB4 or MnB5 type with an average carbon content of 37 or 25.

[0134] The support body 22 may be made of the same material as the undercarriage component 10 .

[0135] In another embodiment, the support body may be made of stainless steel having an ultimate tensile strength between about 650 Mpa and about 800 Mpa and a hardness between about 200 HBW 10 / 3000 and about 270 HBW 10 / 3000.

[0136] In this last embodiment, the ratio between the hardness of the support body 22 and the hardness of the substructural component 10 is comprised between about 0.38 and about 0.64. The ratio between the ultimate tensile strength of the support body 22 and the ultimate tensile strength of the substructural component 10 is comprised between about 0.34 and about 0.55.

[0137] In another embodiment, the support body 22 is made of a thermoplastic material, such as Ertalon PA6 or PA66, for example, having an ultimate tensile strength comprised between 54 MPa and 61 MPa.

[0138] In this case, the material of the support body 22 does not have similar mechanical properties as the material of the substructure components.

[0139] The support body 22 includes a receiving seat 23 (FIG. 5) configured to receive the wear sensor 16 .

[0140] When the wear sensor 16 is inserted into the storage seat 23, the first axial end 16c of the wear sensor 16 is axially aligned with the first axial end 22a of the support body 22, as shown in FIG.

[0141] The sensing portion 16 b of the wear sensor 16 is housed in a housing seat 23 at a second axial end 22 b of the support body 22 .

[0142] In a preferred embodiment of the present invention, wear sensor 16 is held within receiver sheet 23 using an adhesive.

[0143] The support body 22 is configured to be inserted into the cavity 12 with a minimal radial gap to allow the adhesive to form a film that surrounds the support body 22 and adheres to the sidewall 13 of the cavity 12. Once the support body 22 is inserted into the cavity 12 with the adhesive active between the support body 22 and the cavity 12, the support body 22 is rigidly constrained to the sidewall 13 of the cavity 12 and cannot move axially or radially at all relative to the cavity 12.

[0144] In another embodiment, the support body 22 is inserted into the cavity 12 by mechanical interference.

[0145] When the support body 22 is inserted into the cavity 12 by mechanical interference, the support body 22 contacts the side wall 13 of the cavity 12 at least along two contact lines. In other words, the support body 22 has a shape such that any section of the support body along a radial plane has at least two contact points with the side wall 13 of the cavity 12.

[0146] If the degree of mechanical interference is not adequate, the support body 22 may be at least partially coated with an adhesive prior to insertion into the cavity 12 .

[0147] In a preferred embodiment of the present invention, the support body 22 is shaped such that when the support body 22 is inserted into the cavity 12, at least 85% of the cavity 12 is occupied by the support body 22.

[0148] The storage seat 23 has dimensions that prevent the wear sensor 16 from protruding beyond the radial dimension of the support body 22 when the wear sensor 16 is inserted into the storage seat 23, thereby preventing damage to the wear sensor 16 during insertion of the support body 22 into the cavity 12.

[0149] In other words, when the wear sensor 16 is inserted into the storage seat 23 , the side wall 13 of the cavity 12 does not come into contact with the wear sensor 16 .

[0150] In the embodiment shown in Figure 5, the storage sheet 23 comprises a bottom wall 24 and two side walls 25. The side walls 25 extend radially away from the bottom wall 24 and are joined to a radially outer side surface 26 of the support body 22. The bottom wall 25 is radially inward relative to the radially outer side surface 26 of the support body 22. As shown in Figures 4 and 5, the storage sheet 23 is open at the radially outer side wall 26 of the support body 22.

[0151] At the second axial end 22b of the support body 22, the bottom wall 25 of the storage seat is positioned radially inwardly into the support body to facilitate positioning of the sensing portion 16b of the wear sensor 16.

[0152] 5, the support body has a substantially cylindrical shape that is hollowed out by the containment sheet 23. When the support body 22 is inserted into the cavity 12, the cavity 12 is completely occupied by the support body 22 except for the volume enclosed by the containment sheet 23.

[0153] In other embodiments of the support body 22, which are shown diagrammatically in Fig. 3, the storage seat 23 can be obtained on the inside of the support body 22, which is not open on the radially outer side 26 of the support body 22. In these embodiments, the support body 22 is preferably made of a thermosetting plastic material that is cast directly inside the cavity 12 with the wear sensor 16 placed inside the cavity 12. In this case, the support body 22 occupies the cavity 12 completely.

[0154] The present invention has been described above with reference to some preferred embodiments of the present invention, to which various modifications can be made that still remain within the scope of protection of the present invention as defined by the following claims.

Claims

1. A work vehicle component (10), comprising: a cavity (12) obtained in said component (10) having an extension axis (A) and radially delimited by at least one side wall (13), and an opening (14) for said cavity (12) located on the external surface (11) of said component (10); a wear sensor (16) housed within said cavity (12) and having a first axial end (16c) located in said opening (14) for said cavity (12); a support body (22) inserted into the cavity (12) with a first axial end (22a) aligned with the first axial end (16c) of the wear sensor (16); Equipped with the support body (22) is physically connected to the side wall (13) of the cavity (12) and is constrained at least axially to the side wall (13) of the cavity (12), the wear sensor (16) is physically connected to the support body (22) and is constrained at least axially to the support body (22); a ratio of the resistance to localized plastic deformation of the material constituting the support body (22) to the resistance to localized plastic deformation of the material of the component (10) surrounding the cavity (12) is equal to or greater than 0.15, the resistances to localized plastic deformation of the support body (22) and of the component (10) being measured in accordance with ISO 6506-1:2015 using the Brinell scale under identical test conditions, or an ultimate tensile strength of the material constituting the support body (22) is equal to or greater than 15% of the ultimate tensile strength of the material of the component (10) surrounding the cavity (12), the ultimate tensile strength of metallic materials being measured in accordance with ISO 6892-1:2016 and the ultimate tensile strength of plastic or polymeric materials being measured in accordance with ISO 527-1:2019.

2. 2. The work vehicle component (10) of claim 1, wherein the wear sensor (16) comprises a substrate (21) and at least one electrical circuit (17) supported by the substrate (21), the wear sensor (16) comprising a measuring portion (16a) that can be configured to wear down and modify a measurable electrical characteristic of the at least one electrical circuit (17) depending on an extent of wear.

3. The work vehicle component (10) of claim 2, wherein the support body (22) extends axially over a length at least equal to an axial length of the measuring portion (16a) of the wear sensor (16).

4. The work vehicle component (10) of claim 2 or 3, wherein the substrate (21) and the at least one electrical circuit (17) of the wear sensor (16) are not in direct contact with the sidewall (13) of the cavity (12).

5. A work vehicle component (10) as described in any one of claims 1 to 4, wherein the support body (22) has a section, taken along a predetermined radial plane, having an area of ​​at least 30% of the cross-sectional area of ​​the cavity (12) on a section taken along the same predetermined radial plane.

6. The work vehicle component (10) of any one of claims 1 to 5, wherein the volume of the support body (22) is at least equal to 15% of the volume of the cavity (12).

7. The work vehicle component (10) of any one of claims 1 to 6, wherein the support body (22) is constrained to the side wall (13) of the cavity (12) using an adhesive.

8. The work vehicle component (10) of any one of claims 1 to 7, wherein the support body (22) is made of metal.

9. The work vehicle component (10) of any one of claims 1 to 7, wherein the support body (22) is made of a plastic material.

10. The work vehicle component (10) of any one of claims 1 to 9, wherein the support body (22) and the component (10) are made of the same material.

11. The work vehicle component (10) of any one of claims 1 to 10, wherein the wear sensor (16) is a flexible printed circuit (FPC).

12. 12. The work vehicle component (10) of claim 1, wherein the support body (22) is provided with a storage seat (23) for the wear sensor (16), and the wear sensor (16) is restrained in the storage seat (23).

13. The work vehicle component (10) of any one of claims 1 to 6, wherein the wear sensor (16) is embedded in the support body (22).

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