JP7742797B2 - hydraulic excavator - Google Patents

Description

The present invention relates to a hydraulic excavator.

This type of hydraulic excavator is equipped with track-type travel devices on both the left and right sides of the lower running body, designed for travel on unleveled terrain, and a front work area equipped with a bucket and a driver's cab are mounted on an upper rotating body that is rotatably connected to the lower running body. For example, a track-type travel device consists of an endless track wound around a drive sprocket, an idler, and several rollers. When the left and right drive sprockets are rotated by a hydraulic motor for travel mounted on the lower running body, the left and right tracks are driven independently, guided by the idler and each roller, and the hydraulic excavator travels straight or steers depending on the drive direction and drive speed of the left and right tracks.

When a track-type traveling device is in operation, the outer surfaces of the idlers and rollers come into contact with the tracks and gradually wear away. Although a highly wear-resistant hardened layer is formed on the outer surfaces through surface treatment, if the hardened layer disappears due to wear, the tracks will no longer function properly as they are guided. Therefore, the idlers and rollers must be replaced before they reach their service life limit. Patent Document 1, for example, discloses a track inspection device for bulldozers that estimates the amount of wear on the idlers and rollers of the track-type traveling device. This track inspection device detects the rotational speeds of the drive sprocket, idlers, and rollers while the bulldozer is traveling, and estimates the amount of wear on each based on the rotational speed of the idlers and rollers relative to the rotational speed of the drive sprocket.

U.S. Patent No. 9,371,630

However, because the ground on which this type of construction machinery works is uneven, the idlers and rollers are subject to influences from the ground, such as soil, gravel, mud, and the like, as well as the effects of uneven ground. For example, if soil or sand gets caught between the track and the idler or roller, smooth rotation is not possible. In such cases, the rotational speed of the idler or roller cannot be accurately detected, resulting in errors in estimating the amount of wear and, ultimately, in determining when to replace them.

The present invention was made to solve these problems, and its purpose is to provide a hydraulic excavator that can accurately estimate the wear state of the idlers and rollers of the track-type traveling device, regardless of the condition of the ground on which work is being carried out.

To achieve the above object, the hydraulic excavator of the present invention is provided with a track-type traveling unit on each of the left and right sides of a lower traveling body, each consisting of an endless track wound between a drive sprocket and multiple driven rollers, and an articulated front working unit connected to a rotatable upper rotating body on the lower traveling body. The hydraulic excavator is equipped with a control device that inspects at least one of the left and right track-type traveling units, and includes a wear amount estimation unit that drives the track-type traveling unit to be inspected and estimates the amount of wear on the driven rollers, and a jack-up determination unit that determines the jacked-up state in which the front working body touches the ground and separates the track-type traveling unit to be inspected from the ground. The wear amount estimation unit estimates the amount of wear on the driven rollers when the jack-up determination unit determines that the track-type traveling unit to be inspected is in a jacked-up state.

The hydraulic excavator of the present invention makes it possible to accurately estimate the wear condition of the idlers and rollers of the track-type traveling device, regardless of the condition of the ground on which work is being carried out.

FIG. 1 is a side view showing a hydraulic excavator according to a first embodiment. FIG. 2 is a partial detailed view of the left side frame of the hydraulic excavator with the side wall removed. FIG. 3 is a plan view corresponding to FIG. 2 . FIG. 10 is a characteristic diagram showing the relationship between the rotation amount of the idler and carrier roller and the operating time when the crawler belt is driven only for a measurement section. 3 is a cross-sectional view taken along line V-V in FIG. 2, showing a sensor housing portion provided in the yoke. 3 is a detailed view of part A in FIG. 2 showing a sensor fixing bracket provided on a side frame. FIG. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6 showing the sensor fixing bracket. FIG. 2 is a control block diagram showing the functions of a controller. 4 is a flowchart showing a crawler inspection routine executed by the controller of the first embodiment. 10 is a flowchart illustrating a track inspection routine executed by the controller. 10 is a flowchart showing a tension/failure determination value update routine executed by the controller. FIG. 10 is an explanatory diagram showing the hydraulic excavator with the left track-type traveling device jacked up. FIG. 10 is a diagram showing a control map for calculating a correction coefficient Kn from an adjuster protrusion amount L. FIG. 10 is a partial detailed view of the hydraulic excavator according to the second embodiment, with a side wall removed from the left side frame. FIG. 15 is a plan view corresponding to FIG. 14. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 14, showing the rotation amount sensor built into the yoke. 15 is a detailed view of part B in FIG. 14 showing a rotation amount sensor built into the side frame. FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 17, showing the rotation amount sensor. 10 is a flowchart showing a crawler inspection routine executed by a controller according to a second embodiment. 10 is a flowchart showing a track inspection routine executed by the controller.

[First embodiment]
A first embodiment of a hydraulic excavator embodying the present invention will now be described.
1 is a side view showing a hydraulic excavator according to this embodiment, and first, a general configuration of the hydraulic excavator will be described based on this drawing. In the following description, forward/backward, left/right, and up/down directions are expressed from the perspective of an operator riding on the hydraulic excavator.

A track-type travelling device 3 is provided on each of the left and right sides of the undercarriage 2 of the hydraulic excavator 1. The track-type travelling device 3 is configured by wrapping an endless track 3e, made up of multiple connected track plates, around a drive sprocket 3a, an idler 3b (corresponding to the "driven roller" of the present invention), a carrier roller 3c (corresponding to the "driven roller" of the present invention), and a track roller 3d. When the left and right drive sprockets 3a are rotated by a hydraulic travel motor (not shown) provided on the undercarriage 2, the left and right tracks 3e are independently guided circumferentially by the idler 3b and each roller 3c, 3d, and the hydraulic excavator 1 travels straight or steers according to the drive direction and drive speed of the left and right tracks 3e.

An upper rotating body 4 is mounted on the lower traveling body 2 via a rotating device 2a, and the upper rotating body 4 is driven to rotate by a hydraulic rotating motor (not shown) of the rotating device 2a. A multi-articulated work front 5 is mounted in front of the upper rotating body 4, and is composed of a boom 6, an arm 7, and a bucket 8. The angle of the boom 6 is changed by a boom cylinder 6a, the angle of the arm 7 is changed by an arm cylinder 7a, and the angle of the bucket 8 is changed by a bucket cylinder 8a.

A cab 10 for the operator is provided at the front of the frame 9 of the upper rotating body 4, and a fuel tank 11, machinery room 12, counterweight 13, etc. are provided behind the cab 10 on the frame 9. Although not shown, an engine is mounted in the machinery room 12, and hydraulic oil is supplied from a hydraulic pump driven by the engine to operate the above-mentioned traveling or swing hydraulic motors and each of the hydraulic cylinders 6a-8a.

Figure 2 is a detailed view of the portion of Figure 1 with the side wall removed from the left side frame, and Figure 3 is a plan view corresponding to Figure 2. Note that the following description will focus on the track adjustment device 15 that adjusts the tension of the track 3e of the left-side track-type traveling unit 3, but the right-side track adjustment device has the same symmetrical structure.

As shown in Figure 3, the track frame 16 that constitutes the lower traveling body 2 is made up of side frames 18 connected to both the left and right sides of a center frame 17, and these side frames 18 support the drive sprocket 3a, idler 3b, carrier roller 3c, and track roller 3d.

As shown in Figures 2 and 3, the side frame 18 is a rectangular tube extending in the front-to-rear direction, and is closed at its front and rear ends by a front wall 18a and a rear wall (not shown). The base ends of a pair of left and right guide rails 19 are fixed to the front wall 18a, and an idler 3b is disposed between each guide rail 19. A guide groove 20 extending in the front-to-rear direction is formed between the pair of upper and lower rail members 19a, 19b that make up each guide rail 19. A pair of left and right tip ends 21a of a yoke 21 that is Y-shaped in plan view are disposed within each guide groove 20 so as to be slidable in the front-to-rear direction, and each tip end 21a rotatably supports the left and right ends of the shaft 22 of the idler 3b, respectively.

The base end 21b of the yoke 21 extending rearward protrudes into the side frame 18 through a communication hole 18b in the front wall 18a and is connected to the track adjustment device 15. As shown in Figure 1, the guide rail 19 is concealed by the side wall 18c, and the track adjustment device 15 is concealed by the side wall 18d.

The configuration of the track adjuster 15 is well known, as seen in, for example, JP 2020-152334 A, and therefore only a brief description will be provided. The track adjuster 15 is configured to bias the yoke 21 in a protruding direction (to the left in FIG. 2) using a compression spring (not shown), while an adjuster cylinder maintains the position of the yoke 21 against this biasing force. When the rod 23 (shown in FIG. 2) expands or contracts in response to the supply or discharge of grease to the adjuster cylinder, the yoke 21, biased by the compression spring, displaces in the fore-and-aft direction, thereby adjusting the fore-and-aft position of the idler 3b and, ultimately, the tension of the track 3e. The fore-and-aft position of the adjuster cylinder's rod 23 (hereinafter referred to as the adjuster extension amount L, which corresponds to the "track adjuster actuation amount" in this specification) is detected by a stroke sensor 24 (corresponding to the "actuation amount detection unit" in this specification), and this adjuster extension amount L is a value that correlates with the length of the track 3e, which gradually expands with operation.

However, during operation of the track-type traveling device 3, the outer surfaces of the idler 3b and rollers 3c, 3d come into contact with the track 3e and gradually wear away, making it necessary to replace the idler 3b and rollers 3c, 3d before they reach their service limits. Patent Document 1, for example, discloses a technology for estimating the wear on the idler 3b and rollers 3c, 3d, in which the rotational speeds of the drive sprocket, idler, and rollers are detected while the bulldozer is traveling, and the wear on the idler and rollers is estimated based on the relative rotational speeds. However, because construction machinery works on uneven ground, the accurate rotational speeds of the idler and rollers cannot be detected due to the influence of the ground, resulting in errors in the wear estimation.

In light of these problems, the inventors focused on jacking up, an operation unique to hydraulic excavators 1. The technology of Patent Document 1 involves actually running a bulldozer, which means that it is unavoidable that it is affected by the ground. In contrast, with hydraulic excavators 1, it is possible to use the front work unit 5 to create a jacked-up state in which the track-type traveling unit 3 is separated from the ground (hereinafter simply referred to as jacking up the track-type traveling unit 3), making it possible to create a pseudo-traveling state (an operating state of the track-type traveling unit 3) without being affected by the ground.

Based on the above knowledge, in the hydraulic excavator 1 of this embodiment, the track-type traveling unit 3 is jacked up to estimate the amount of wear on the idler 3b and rollers 3c and 3d. Additionally, in this embodiment, the condition of the track-type traveling unit 3 is inspected based on the estimated amount of wear (the amount of rotation N, described below, which corresponds to the "rotational state" in this invention), and a series of inspection processes are executed to suggest maintenance work (part replacement, adjustment of the tension of the track 3e, repairs, etc.) that is currently required for the track-type traveling unit 3 based on the inspection results. For this process, the hydraulic excavator 1 is equipped with a track inspection device 26, the details of which are described below.

Figure 4 is a characteristics diagram showing the relationship between the rotation amount N of the idler 3b and carrier roller 3c and the operating time when the crawler 3e is driven only through the measurement section. Figure 5 is a cross-sectional view taken along line V-V in Figure 2, showing the sensor housing provided in the yoke 21. Figure 6 is a detailed view of part A in Figure 2, showing the sensor fixing bracket provided on the side frame 18. Figure 7 is a cross-sectional view taken along line VII-VII in Figure 6, showing the same sensor fixing bracket.

First, an overview of the wear amount estimation process will be explained. In this embodiment, the wear amounts of the idler 3b and the front and rear carrier rollers 3c are estimated. The estimation principle is based on the finding that a correlation exists between the amount of rotation N of the idler 3b and carrier roller 3c when the crawler 3e is driven over a predetermined section (hereinafter referred to as the measurement section) and the amount of wear for each. When the crawler 3e is driven by the drive sprocket 3a, the outer peripheral surfaces of the idler 3b and carrier roller 3c move circumferentially in accordance with the measurement section of the crawler 3e, and the amount of rotation N in the measurement section is determined by the amount of this circumferential movement. As the idler 3b and carrier roller 3c reduce in diameter due to wear, the amount of rotation N gradually increases accordingly. Therefore, as shown in Figure 4, a correlation exists between the amount of rotation N and the amount of wear.

The amount of rotation N of the idler 3b and carrier roller 3c is measured when the crawler 3e is driven only over the measurement section. Then, by comparing this amount of rotation N with a replacement determination value Nlimit, which is preset as the usage limit of the idler 3b or carrier roller 3c (point d in the diagram), it becomes possible to determine whether or not each needs to be replaced.

To this end, each of the left and right track-type traveling units 3 is equipped with a master pin sensor 27 (corresponding to the "measurement section detection unit" of the present invention) to detect the measurement section of the track 3e, and a rotation amount sensor 28 (corresponding to the "rotation state detection unit" of the present invention) to detect the amount of rotation N. The following explanation describes the mounting state of the sensors 27, 28 on the left track-type traveling unit 3, but the right side has the same symmetrical structure.

As shown in Figures 2 and 3, the master pin sensor 27 is equipped with a light-emitting unit and a light-receiving unit (not shown), and is configured as a so-called photoelectric sensor that detects objects by reflecting light. The master pin sensor 27 is fixed to the outer peripheral surface of the swing mechanism 2a, its light-emitting direction is set to the left, and its vertical position coincides with the upper tension point of the track 3e. Although not shown, the track 3e is made up of multiple connected track plates, and a master pin 29 that can be removed and attached during track 3e maintenance is used at one connection point. A reflector 30 is affixed to the inner end of the master pin 29, and the reflector 30 is detected by the master pin sensor 27 every time the track 3e moves and reaches a position to the left of the master pin sensor 27, in other words, every time the track 3e completes one revolution.

The rotation amount sensor 28 is detachable from the body of the hydraulic excavator 1 and is shared between the idler 3b and the front and rear carrier rollers 3c (i.e., a single sensor is used). For this reason, sensor mounting portions 31, 32 (each corresponding to the "mounting portion" in the present invention) to which the rotation amount sensor 28 can be attached are provided in the vicinity of the idler 3b and the carrier roller 3c, respectively.

The sensor mounting portion 31 of the idler 3b is provided on the yoke 21. As shown in FIG. 5, a sensor housing 33 is recessed from the left side of the left end 21a of the yoke 21. The rotation amount sensor 28 is disposed within the sensor housing 33 and can be secured with screws (not shown). The rotation amount sensor 28 is also configured as a photoelectric sensor. When secured within the sensor housing 33, its light-emitting and light-receiving portions (not shown) face the left side of the idler 3b through the communication hole 33a of the sensor housing 33. A reflector 34 is attached to an eccentric position on the left side of the idler 3b. As the idler 3b rotates, the reflector 34 is detected by the rotation amount sensor 28 each time it reaches a position to the right of the rotation amount sensor 28—in other words, with each rotation of the idler 3b. Note that the master pin sensor 27 and rotation amount sensor 28 are not limited to these and can be replaced with sensors using any detection principle.

The sensor fixing portions 32 of the front and rear carrier rollers 3c are each provided on the upper surface 18e of the side frame 18. Below, the sensor fixing portion 32 of the front carrier roller 3c will be explained with reference to Figures 6 and 7, but the rear carrier roller has the same structure.

First, regarding the carrier roller 3c, a roller support portion 36 is fastened with bolts 37 to a base 35 welded to the upper surface 18e of the side frame 18, and the carrier roller 3c is rotatably supported in a cantilevered manner via a shaft 38 on the left side of the roller support portion 36. Furthermore, a through-hole 18f is formed through the upper surface 18e, and soil and sand scraped off the crawler belt 3e by contact with the carrier roller 3c are discharged downward through the through-hole 18f.

To the left of this carrier roller 3c, the base end 39a of a bracket 39 is fastened to the top surface 18e of the side frame 18 with a bolt 40. The tip end 39b is bent at a right angle from the base end 39a and stands upright on the side frame 18. A rotation amount sensor 28 can be fixed to the left side of the tip end 39b with a screw (not shown). When fixed to the bracket 39, the rotation amount sensor 28 has its light-emitting and light-receiving sections facing the left end surface of the carrier roller 3c via a communication hole 39c formed through the tip end 39b. A reflector 41 is affixed to an eccentric position on the left end surface of the carrier roller 3c. Each time the reflector 41 reaches a position to the right of the rotation amount sensor 28 as the carrier roller 3c rotates, in other words, with each rotation of the carrier roller 3c, the reflector 41 is detected by the rotation amount sensor 28.

Under normal circumstances, when wear estimation is not being performed, the rotation amount sensor 28 is detached from both sensor mounting portions 31, 32, and its reflectors 34, 41 and the reflector 30 of the master pin sensor 27 are also detached. Dust and other particles are generated, particularly near the ground, during operation of the hydraulic excavator 1, and this is intended to prevent malfunction of the rotation amount sensor 28 and damage to the reflectors 30, 34, 41. In this embodiment, the master pin sensor 27, which is located in a position less susceptible to dust, is fixed, but like the rotation amount sensor 28, this sensor 27 may also be detachable and attached only when necessary.

Figure 8 is a control block diagram showing the functions of the controller 43 (control device). The controller 43 consists of a storage device (ROM, RAM, etc.) with a built-in control program, a central processing unit (CPU), a timer counter, etc. The input side of the controller 43 is connected to the stroke sensor 24, master pin sensor 27, and rotation amount sensor 28, as well as to the inspection start button 44, preparation complete button 45, and left and right tension adjustment complete buttons 47L, 47R. In addition, the output side of the controller 43 is connected to a display 46 (corresponding to the "display unit" in this invention) that can be viewed by the operator.

The buttons 44, 45, 47L, 47R and display 46 are installed in the operator's cab 10 of the hydraulic excavator 1. The inspection start button 44 is operated to instruct the start of a series of inspection processes, and the preparation complete button 45 is operated when preparatory work such as jacking up prior to the inspection process is complete. In addition, the left and right tension adjustment complete buttons 47L, 47R are operated when tension adjustment of the left or right track 3e is complete. The display 46 functions to guide the operator through preparatory work prior to the inspection process and to display the inspection results.

Normally, the rotation amount sensor 28 is disconnected from the controller 43 and stored in a designated storage location, and when it is fixed to the sensor fixing parts 31, 32 of the vehicle body to perform an inspection, the connection work to the controller 43 is performed at the same time.
The controller 43 includes a wear amount estimation unit 43a, a jack-up determination unit 43b, a use limit determination unit 43c, a tension adjustment determination unit 43d, a failure determination unit 43e, a failure determination value update unit 43f, and a tension determination value update unit 43g.

The wear amount estimation unit 43a measures the rotation amount N of the idler 3b and carrier roller 3c in the measurement section of the crawler 3e as the amount of wear for each. The jack-up determination unit 43b determines the jack-up state of the left and right crawler-type traveling devices 3.

The service limit determination unit 43c determines whether the idler 3b or the carrier roller 3c has reached its service limit. The tension adjustment determination unit 43d determines whether the tension of the crawler belt 3e needs to be adjusted. The malfunction determination unit 43e determines whether the idler 3b or the carrier roller 3c has malfunctioned.
The fault determination value update unit 43f updates the fault determination value Ntrouble that is used in the determination process of the fault determination unit 43e. The tension determination value update unit 43g updates the tension determination value Ntension that is used in the determination process of the tension adjustment determination unit 43d.

9 and 10 are flowcharts showing a track inspection routine executed by the controller 43. The controller 43 executes this routine at predetermined control intervals while the hydraulic excavator 1 is in operation.
For the sake of convenience, it is assumed below that the track adjustment device 15 is in a state immediately after manufacture, the idler 3b and the front and rear carrier rollers 3c are brand new, and the tension of the track 3e is adjusted to a specified value. When the hydraulic excavator 1 starts operating, the amount of rotation N of the idler 3b and carrier roller 3c in the measurement section of the track 3e gradually increases from Ninitial, which corresponds to the initial value, as wear progresses, as shown in Figure 4.

The inspection process inspects the track-type traveling device 3 based on the rotation amount N, and determines the necessary maintenance work based on the inspection results. In order to perform this process, the values of requirements 1) to 4) described below are set in advance, as shown in Figure 4.

1) A replacement determination value Nlimit corresponding to the rotation amount N when the idler 3b and the carrier roller 3c reach their usage limit.
Since the outer diameters of the idler 3b and carrier roller 3c when worn down to their service limits requiring replacement are known, a rotation amount Nlimit corresponding to the measurement section of the crawler belt 3e is set in advance based on each outer diameter. For example, the replacement determination value Nlimit for each of the idler 3b and carrier roller 3c is set to a value of about +30% of their respective initial values Ninitial.

2) An increase amount ΔN1 corresponding to the increase in the rotation amount N from the time when the tension of the crawler belt 3e is adjusted until the time when the next tension adjustment is required.
Slack in the crawler belt 3e due to stretching occurs due to various factors, such as wear of the pins connecting the track shoes, but as the slack in the crawler belt 3e progresses, wear of the idler 3b and the carrier roller 3c also progresses. Therefore, an increase in the rotation amount N correlates with the progression of slack in the crawler belt 3e, and the rotation amount N can be used as an index for determining whether or not tension adjustment of the crawler belt 3e is required. Therefore, in this embodiment, the rotation amount N of the idler 3b is used as an index, and the relationship between the rotation amount N and the slack in the crawler belt 3e is derived based on a test performed in advance on an actual vehicle, and then an increase ΔN1 in the idler rotation amount N until tension adjustment is required is preset. Of course, the need for tension adjustment may also be determined based on the rotation amount N of the carrier roller 3c instead of the idler 3b.

3) A decrease ΔN2 in the rotation amount N that occurs when the idler 3b or the carrier roller 3c fails.
The malfunction may be, for example, a lack of oil in the bearing or the intrusion of foreign matter, and any of these causes will manifest as a decrease in rotation. Therefore, in order to determine when the rotation amount N, which should increase with the progression of wear, has decreased, a decrease amount ΔN2 is set in advance.
Of course, the wear progression characteristics differ between the idler 3b and the carrier roller 3c, so the replacement determination value Nlimit and the decrease amount ΔN2 are set individually.

4) Measurement section of the crawler 3e when measuring the rotation amount N (10 laps).
In this embodiment, the minimum rotation amount N that the rotation amount sensor 28 can detect is one revolution, so the rotation amount N measured in the measurement section may contain an error equivalent to up to one revolution. Therefore, by setting the measurement section to a sufficiently long period of 10 revolutions, the influence of the error is suppressed, enabling accurate measurement of the rotation amount N and, ultimately, accurate estimation of the amount of wear. However, the measurement section is not limited to this and can be changed as desired. Furthermore, to increase the resolution of the rotation amount sensor 28, for example, instead of the reflector 34, markers may be provided protruding from the idler 3b or the carrier roller 3c at 10° intervals and detected by the rotation amount sensor 28. In this case, the desired detection accuracy of the rotation amount N can be ensured even if the measurement section is further shortened.

Meanwhile, the inspection process is carried out in the order of left side and right side, and with the corresponding track-type traveling device 3 jacked up, the idler 3b, front carrier roller 3c, and rear carrier roller 3c are inspected in that order. The inspection process involves measuring the amount of rotation N, determining whether or not there is a malfunction based on that value, and further determining whether or not the usage limit has been reached. In addition, when inspecting the idler 3b, it is also determined whether or not adjustment of the tension of the track 3e is necessary.

In the routines of Figures 9 and 10, the controller 43 determines in step S1 whether the inspection start button 44 has been operated, and if the result is No (negative), the routine is temporarily terminated. The operator of the hydraulic excavator 1 operates the inspection start button 44 at any interval (for example, once a month) and checks whether maintenance is required for the track-type traveling device 3 based on the information displayed on the display 46. If the determination in step S1 is Yes (affirmative), in step S2, the display 46 is used to provide guidance on preparatory work that should be performed prior to the inspection process, and in the subsequent step S3, it is determined whether the preparation complete button 45 has been operated (jack-up determination unit 43b).

The guidance sequentially displays on the display 46 the following: jacking up either the left or right track-type traveling unit 3; attaching the rotation amount sensor 28 to the sensor fixing portions 31 and 32; connecting the wiring of the rotation amount sensor 28 to the controller 43; and attaching the reflectors 30, 34, and 41 to the master pin 29 of the track 3e, the idler 3b, and each carrier roller 3c. The first guidance for inspecting the left track-type traveling unit 3 instructs the operator to jack up the left track-type traveling unit 3, attach the rotation amount sensor 28 to the sensor fixing portion 31 of the idler 3b, and attach each reflector 30, 34, and 41.

Based on this guidance, the hydraulic excavator 1 maintains a posture in which the bucket 8 of the front work unit 5 is on the ground and the left tracked traveling unit 3 is jacked up, as shown in FIG. 12. When all of the guided preparation work is completed, the operator operates the preparation complete button 45. If the determination in step S3 is Yes, the left tracked traveling unit 3 is driven in step S4, and the rotation amount N of the idler 3b in the measurement section is measured in the following step S5 (wear amount estimation unit 43a). For example, the start point of the measurement section is determined to be the time when the master pin sensor 27 first detects the reflector 34 after starting to drive the tracked traveling unit 3, and the end point of the measurement section is determined to be the time when the reflector 34 is detected the 11th time. As a result, the tracked traveling unit 3 makes 10 revolutions during the measurement section, and the number of times the rotation amount sensor 28 detects the reflector 41 during that time is measured and used as the rotation amount N of the idler 3b.

At this time, the left-side track-type traveling unit 3 of the hydraulic excavator 1 is jacked up, but the track 3e is driven by the drive sprocket 3a in the same way as during normal travel, and the idler 3b and carrier roller 3c rotate accordingly. Furthermore, because the track 3e is separated from the ground by the jacking up, problems such as soil and sand on the ground becoming caught between the track 3e and the idler 3b or carrier roller 3c are prevented. Therefore, the idler 3b and carrier roller 3c rotate in response to the drive of the track 3e without being affected by the ground.

In step S6, the adjuster protrusion amount L detected by the stroke sensor 24 is read, and in the following step S7, a correction coefficient Kn is calculated from the adjuster protrusion amount L based on the control map in Figure 12. When the track 3e stretches during operation, the measurement section becomes longer, the rotation amount N increases, and the correlation with the amount of wear is lost. Adjusting the tension of the track 3e does not change the situation, but the adjuster protrusion amount L at this time correlates with the length of the track 3e and, ultimately, the measurement section. Therefore, the purpose of the correction coefficient Kn is to correct the rotation amount N to compensate for the effects of stretching the track 3e.

For example, as shown in Figure 13, the correction coefficient Kn is set to 1 when the adjuster projection amount L is the amount at which the track adjustment device 15 was manufactured. As the adjuster projection amount L increases (+), the correction coefficient Kn is set to a value less than 1, and as the adjuster projection amount L decreases (-), the correction coefficient Kn is set to a value less than 1. A decrease in the adjuster projection amount L occurs when one track plate is removed to shorten the extended track 3e. However, even if the number of track plates is reduced, the correlation between the adjuster projection amount L and the length of the track 3e shown in Figure 12 does not change. In the following step S8, the rotation amount N is multiplied by this correction coefficient Kn. This corrects the rotation amount N to a value that is not affected by the length of the track 3e.

From step S9 onwards, each inspection process is carried out based on the rotation amount N of the idler 3b. To facilitate understanding, the process contents will be explained in order from the time of manufacture to the limit of use, following the progression of operating time (amount of wear) shown in Figure 4.
When the hydraulic excavator 1 begins operation after manufacture, the rotation amount N of the idler 3b in the measurement section of the crawler 3e gradually increases from the initial value Ninitial as wear progresses, as shown in Figure 4. The rotation amount Ninitial is known from the outer diameter of the idler 3b and the measurement section of the crawler 3e immediately after manufacture. Therefore, based on the rotation amount Ninitial, at the time of manufacture, a tension determination value Ntension (=Ninitial+ΔN1) for determining whether or not tension adjustment of the crawler 3e is necessary, and a fault determination value Ntrouble (=Ntrouble-ΔN2) for determining whether or not a fault exists in the idler 3b are respectively set. Note that at the time of manufacture, the fault determination value Ntrouble of the carrier roller 3c is also set.

In step S9, the controller 43 determines whether the rotation amount N is equal to or greater than the replacement determination value Nlimit (use limit determination unit 43c), and in step S10 determines whether the rotation amount N is equal to or less than the malfunction determination value Ntrouble (fault determination unit 43e). Furthermore, if it determines in step S11 that the idler 3b is being inspected, it determines in step S12 whether the rotation amount N is equal to or greater than the tension determination value Ntension (tension adjustment determination unit 43d).

For example, in the case of point a on the idler characteristic line N shown in Figure 4, a No determination is made in steps S9 and S10, and then a No determination is made in step S12 via step S10, and the process proceeds to step S13. In step S13, a message indicating that the left track-type traveling device 3 is normal is displayed on the display 46, and the process then proceeds to step S14. Therefore, based on the display 46, the operator at this time recognizes that the idler 3 is not malfunctioning and has not reached its service limit, and also recognizes that tension adjustment of the track 3e is not necessary.

Furthermore, when it becomes necessary to adjust the tension of the track 3e, as shown by point b in Figure 4, a Yes determination is made in step S12 and the process proceeds to step S15. In step S15, a message indicating that the tension of the left track 3e should be adjusted is displayed on the display 46, and the process proceeds to step S14. Therefore, the operator at this time recognizes that the tension of the left track 3e needs to be adjusted based on the display 46, and then performs the adjustment. This tension adjustment work may be performed at another time after all inspection processes have been completed, or, since the left track 3e is currently in a jacked-up state, it may be performed using this opportunity.

In either case, once the slack in the track 3e has been eliminated and the work is complete, the operator operates the tension adjustment completion button 47L on the left. Based on this operation, the tension determination value Ntension and the trouble determination value Ntrouble are updated by the routine in Figure 11 (the same applies to the carrier roller 3c), the details of which will be described later.

Furthermore, if a failure occurs in the idler 3b, the rotation amount N will deviate from the idler characteristic line N in the direction of decreasing rotation, as shown by point c in Figure 4. Therefore, a Yes determination is made in step S10 and the process proceeds to step S16. In step S16, a message indicating that a failure has occurred in the left idler 3b and that repair is required is displayed on the display 46, and the process proceeds to step S14. Therefore, the operator at this time recognizes the failure of the left idler 3b based on the information on the display 46 and carries out appropriate repairs, such as greasing the bearings.

Furthermore, when the idler 3b reaches its usage limit, as shown by point d on the idler characteristic line N in Figure 4, a Yes determination is made in step S9 and the process proceeds to step S17. In step S17, a message indicating that the left idler 3b has reached its usage limit and requires replacement is displayed on the display 46, and the process proceeds to step S14. Therefore, the operator at this time recognizes that the left idler 3b needs to be replaced based on the information on the display 46 and proceeds with the replacement.

After displaying the display 46 in any of steps S13, 15-17 as described above, step S14 determines whether inspection processing for the idler 3b and the front and rear carrier rollers 3c has all been completed. Because inspection processing for only the idler 3b has been completed, a No determination is made and the process returns to step S2. In step S2, guidance is provided to remove the rotation amount sensor 28 from the sensor mounting portion 31 of the idler 3b and mount it on the sensor mounting portion 32 of the front carrier roller 3c. At this point, the left track-type traveling unit 3 remains in a jacked-up state, following the previous inspection processing for the idler 3b.

The subsequent processing from steps S3 to S17 is basically the same as for the idler 3b. In steps S3 to S8, the amount of rotation of the front carrier roller 3c is measured, and in steps S9 and S10, the amount of rotation N is compared with the replacement determination value Nlimit and the malfunction determination value Ntrouble set for the carrier roller 3c. For example, at point a on the carrier roller characteristic line N shown in Figure 4, the operator recognizes that the track-type traveling device 3 is normal based on the normal message in step S13.

Furthermore, if the carrier roller 3c deviates from the carrier roller characteristic line N, as at point c in Figure 4, repair of the carrier roller 3c is carried out based on the repair message in step S16. Furthermore, in the case of point d on the carrier roller characteristic line N in Figure 4, the carrier roller 3c is replaced based on the replacement message in step S17. Note that because the carrier roller 3c is the object of inspection, a No determination is made in step S11, and the processing of steps S12 and S15 is not executed.

Then, the process moves to step S2 via step S14, where inspection processing is performed on the rear carrier roller 3c. However, since the details are the same as for the front carrier roller 3c, a detailed explanation will be omitted. Then, when the process moves back to step S14, all inspection processing on the left side is completed, so a Yes result is made and the process moves to step S18. In step S18, it is determined whether inspection processing on both the left and right track-type traveling devices 3 has been completed, and since the right side has not yet been inspected, a No result is made and the process returns to step S2.

In step S2, the initial guidance for inspecting the right-side tracked traveling unit 3 includes instructions to jack up the right-side tracked traveling unit 3 instead of the left-side tracked traveling unit 3, and instructions to secure the rotation amount sensor 28 to the sensor mounting portion 31 of the idler 3b. The subsequent processing in steps S3 to S17 is the same as for the left-side idler 3b, and then a No determination is made in step S14 to perform inspection processing for the front carrier roller 3c, followed by inspection processing for the rear carrier roller 3c. The processing for these carrier rollers 3c is the same as for the left side.

When the inspection processes for both the left and right sides are completed and a Yes determination is made in step S18, the process proceeds to step S19, where guidance is provided on the final tasks to end the inspection process, and the routine then ends. In more detail, the following tasks are sequentially displayed on the display 46: stopping the jacking up of the right tracked traveling device 3; removing the rotation amount sensor 28 from the sensor fixing portion 32 of the rear carrier roller 3c; disconnecting the wiring of the rotation amount sensor 28 from the controller 43; and removing the reflectors 30, 34, and 41. The operator performs the guided final tasks, and the hydraulic excavator 1 is then prepared to start operation.

In this embodiment, the rotation amount N of the track rollers 3d is not measured, and the carrier rollers 3c are replaced at the same time using their service limits as a guide, but this is not limited to this. For example, a sensor fixing portion 32 may be provided in proximity to each track roller 3d, and a rotation amount sensor 28 may be fixed to each sensor fixing portion 32 in turn during the inspection process. The measured rotation amount N may be used to determine whether each track roller 3d is faulty and whether replacement is required.

On the other hand, when the tension of either the left or right track 3e is adjusted based on the tension adjustment message in step S15 as described above, the operator operates the tension adjustment completion button 47L, 47R on that side. While the hydraulic excavator 1 is in operation, the controller executes the tension/fault determination value update routine shown in FIG. 11 at predetermined control intervals. In step S21 of this routine, it determines whether the left tension adjustment completion button 47L has been operated, and in step S22 it determines whether the right tension adjustment completion button 47R has been operated. If a No determination is made in either process, the routine is temporarily terminated.

If step S21 returns a Yes, then in step S23, the tension determination value Ntension of the left track 3e is updated by adding the increase ΔN1 (Ninitial + ΔN1) (tension determination value update unit 43g), and in step S24, the failure determination value Ntrouble of the left idler 3b and carrier roller 3c is updated by subtracting the decrease ΔN2 (Ntrouble - ΔN2) (failure determination value update unit 43f). Also, if step S22 returns a Yes, in steps S25 and S26, the right tension determination value Ntension and failure determination value Ntrouble are updated to the same content as steps S23 and S24 (tension determination value update unit 43g, failure determination value update unit 43f). Of course, if the tension of both the left and right tracks 3e is adjusted, both the left and right tension determination values Ntension and failure determination values Ntrouble are updated.

As described above, according to this embodiment, either the left or right tracked traveling unit 3 is jacked up and driven, and the rotation amount N of the idler 3b and carrier roller 3c in the measurement section of the track 3e is measured. Based on this rotation amount N, inspection processes are performed to determine the service limit and malfunction of the idler 3b and carrier roller 3c, as well as the need for tension adjustment of the track 3e. In this way, jacking up the tracked traveling unit 3 creates a simulated traveling state, preventing the rotation of the idler 3b and carrier roller 3c from being affected by the ground. Therefore, an accurate rotation amount N can be measured, which correlates with the current amount of wear of the idler 3b and each carrier roller 3c, and accurate inspection results can be obtained based on this rotation amount N.

For example, with regard to the service limit of the idler 3b or carrier roller 3c, the amount of rotation N of each is considered to be the amount of wear, and when the amount of rotation N reaches or exceeds the replacement judgment value Nlimit, a message on the display 46 prompts replacement. Because the replacement time for the idler 3b or carrier roller 3c can be accurately determined based on the accurate amount of rotation N, it is possible to prevent situations in which, for example, replacement is delayed and the hydraulic excavator 1 becomes unable to move, or situations in which the operating costs of the hydraulic excavator 1 rise due to excessively early replacement.

Failures of the idler 3b or carrier roller 3c can also be accurately determined based on the accurate rotation amount N. Specifically, because a failure is determined at an early stage, when the rotation amount N has decreased slightly, appropriate repairs can be carried out early, thereby preventing the hydraulic excavator 1 from becoming unable to travel.

In addition, the need for tension adjustment of the tracks 3e can be accurately determined based on the accurate amount of rotation N, allowing tension adjustment to be carried out at the appropriate time. For example, if adjustment work is delayed, it may interfere with the operation of the hydraulic excavator 1, and conversely, if adjustment work is carried out too early, it may cause operating costs to rise, but these situations can be prevented in advance.

In addition, each time the tension of either the left or right track 3e is adjusted, the tension determination value Ntension and the failure determination value Ntrouble for the side whose tension has been adjusted are updated by the tension/failure determination value update routine in FIG. 11. Therefore, thereafter, the need for tension adjustment of the track 3e is determined in step S12 based on the updated tension determination value Ntension, and the presence or absence of a failure in the idler 3b and carrier roller 3c is determined in step S10 based on the updated failure determination value Ntrouble.

The tension determination value Ntension is a value updated based on the increase ΔN1, using the rotation amount N at the time the tension of the track 3e was adjusted as a reference, and the increase ΔN1 is a value set as the increase in the rotation amount N from the time the tension of the track 3e is adjusted until the next tension adjustment is required. Therefore, the need for the next tension adjustment can be accurately determined based on the updated tension determination value Ntension, and tension adjustment can be performed at an appropriate timing, neither too much nor too little.

Furthermore, in step S10, the failure determination value Ntrouble functions as a threshold value for determining a decrease in rotation of the idler 3b or carrier roller 3c. Because this failure determination value Ntrouble is updated to an appropriate value each time the tension of the crawler 3e is adjusted, it is possible to accurately determine the failure and promptly prompt repair.

In this embodiment, the rotation amount sensor 28 is fixed to the sensor mounting portion 31 near the idler 3b or the sensor mounting portion 32 near the carrier roller 3c only when inspection processing of the track-type traveling device 3 is required, and the reflectors 30, 34, and 41 are affixed to their respective predetermined locations. Because dust and other particles are generated, particularly near the ground, during operation of the hydraulic excavator 1, the sensor mounting portions 31 and 32 and the locations where the reflectors 30, 34, and 41 are attached are exposed to dust and other particles. This can lead to malfunction of the rotation amount sensor 28 and damage to the reflectors 30, 34, and 41. However, because the rotation amount sensor 28 and the reflectors 30, 34, and 41 are removed during operation of the hydraulic excavator 1, these problems can be prevented. As a result, the measurement section corresponding to the drive of the track 3e can be accurately detected, and the rotation amount N of the idler 3b and carrier roller 3c in the measurement section can also be accurately measured, thereby enabling accurate inspections based on the rotation amount N.

In contrast, in this embodiment, the rotation amount N of the idler 3b and carrier roller 3c is measured when the track 3e is driven only through the measurement section, and this rotation amount N is used as an index to determine the service limit and presence or absence of a malfunction of the idler 3b or carrier roller 3c, as well as the need for tension adjustment of the track 3e. The rotation amount N of the idler 3b or carrier roller 3c is determined according to the measurement section of the track 3e, and as the diameter decreases due to wear, the rotation amount N gradually increases accordingly. Furthermore, if the rotation of the idler 3b or carrier roller 3c is hindered due to a lack of oil, or if some kind of malfunction occurs, the rotation amount N decreases accordingly. Because each inspection process is performed using this rotation amount N as an index, each situation can be accurately determined, thereby improving inspection accuracy.

In particular, in this embodiment, a correction coefficient Kn is calculated from the adjuster protrusion amount L, which correlates with the length of the track 3e, based on the control map in Figure 13, and the measured rotation amount N is corrected using the correction coefficient Kn. This makes it possible to compensate for the effects of stretching the track 3e, resulting in a more accurate rotation amount N and, ultimately, more accurate inspection results.

Second Embodiment
Next, a second embodiment of a hydraulic excavator 1 embodying the present invention will be described. The second embodiment differs from the first embodiment in that the rotation amount sensor 28 is built into the body of the hydraulic excavator 1 and is exposed to the outside only when it is necessary to perform an inspection process, but the other configurations are the same as those of the first embodiment. Therefore, the same component numbers are used for common components, and their description will be omitted, with the focus being on the differences.

Figure 14 is a partial detailed view of the left side frame 18 of the hydraulic excavator 1 of this embodiment with the side walls 18c and 18d removed, Figure 15 is a plan view corresponding to Figure 14, and Figure 16 is a cross-sectional view taken along line XVI-XVI in Figure 14, showing the rotation amount sensor 28 built into the yoke 21.

In this embodiment, the rotation amount sensors 28 are individually provided for the idler 3b and the front and rear carrier rollers 3c, which are the detection targets, and are built into the vehicle body in proximity to the detection targets. First, regarding the rotation amount sensor 28 for the idler 3b, the rotation amount sensor 28 is built into the yoke 21 that supports the idler 3b. A sensor housing 51 (corresponding to the "housing" in this invention) is formed in the left tip 21a of the yoke 21, and the sensor housing 51 opens to the right through a communication hole 51a. The rotation amount sensor 28 and drive unit 52 are disposed within the sensor housing 51. As in the first embodiment, the rotation amount sensor 28 is configured as a photoelectric sensor, with its light-emitting portion and light-receiving portion corresponding to the communication hole 51a.

A shielding plate 53 is disposed in the communication hole 51a and is connected to the drive unit 52 via an interlocking arm 54. Driven by the drive unit 52, the shielding plate 53 slides between the closed position indicated by the solid line and the open position indicated by the two-dot chain line. When the shielding plate 53 is in the closed position, the communication hole 51a is closed, isolating the sensor housing 51 from the outside and preventing the intrusion of dust and other particles. When the shielding plate 53 is in the open position, the communication hole 51a is open, exposing the rotation amount sensor 28 to the outside through the communication hole 51a. Its light-emitting and light-receiving parts face the left side of the idler 3b, enabling it to detect the reflector 34.

17 is a detailed view of part B in FIG. 14 showing the rotation amount sensor 28 built into the side frame 18, and FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 17 showing the same rotation amount sensor 28.
The rotation amount sensors 28 for the front and rear carrier rollers 3c are respectively built into the side frames 18. The rotation amount sensor 28 for the front carrier roller 3c will be described below with reference to Figures 17 and 18, but the rotation amount sensor 28 for the rear carrier roller 3c has the same structure.

Within the side frame 18, a partition wall 55 defines a sensor housing 56 (corresponding to the "housing" in this specification) at a position corresponding to the left of the carrier roller 3c. This sensor housing 56 opens upward through a communication hole 18g that penetrates the top surface 18e of the side frame 18. A rotation amount sensor 28 configured as a photoelectric sensor and a drive unit 57 are disposed within the sensor housing 56, and the communication hole 18g is closed by a shielding plate 58 disposed from above. The rotation amount sensor 28 is fixed to the underside of this shielding plate 58, with the light-emitting and light-receiving portions facing rightward. The underside of the shielding plate 58 is connected to the shaft 60 of the drive unit 57 via a pair of left and right interlocking arms 59. Drive of the drive unit 57 around the shaft 60 causes the shielding plate 58 to open and close between the closed position indicated by the two-dot chain line in FIG. 17 and the open position indicated by the solid line.

When the shielding plate 58 is in the closed position, the communication hole 18g is closed and the rotation amount sensor 28 is stored in the sensor housing portion 56. This shielding plate 58 isolates the sensor housing portion 56 from the outside, preventing the intrusion of dust and other particles. When the shielding plate 58 is in the open position, the communication hole 18g is opened and the rotation amount sensor 28 is pulled upward from the sensor housing portion 56 along with the shielding plate 58, with its light-emitting and light-receiving portions facing the left side of the carrier roller 3c and able to detect the reflector 41.

As shown in Figure 8, in this embodiment, the rotation amount sensors 28 are always connected to the input side of the controller 43, and the drive units 52, 57 are always connected to the output side of the controller 43. Therefore, during the inspection process, the operation of attaching and detaching the rotation amount sensors 28 described in the first embodiment is not necessary, and the operation of connecting and disconnecting wiring to the controller 43 is also not necessary.

Figures 19 and 20 are flowcharts showing the track inspection routine executed by the controller 43. Differences from the first embodiment include the addition of processing related to the drive units 52 and 57, the corresponding changes to the guidance content of steps S2 and S21, and the parallel execution of inspection processing related to the idler 3b and the front and rear carrier rollers 3c.

That is, when the inspection start button 44 is operated in step S1, the left drive units 52, 57 are first driven in step S31 to switch the shielding plates 53, 58 to the open position. This enables the left rotation amount sensors 28 to detect the respective reflectors 34, 41, and the guidance in the following step S2 instructs the left track-type traveling device 3 to be jacked up.

The subsequent processing in steps S3 to S17 is essentially the same as in the first embodiment, except that it is performed in parallel for the idler 3b and each carrier roller 3c. Therefore, in steps S4 to S8, the rotation amount N of each idler 3b and each carrier roller 3c is measured, and in steps S9, S10, and S12, the service limit and malfunction of the idler 3b and each carrier roller 3c are determined based on the rotation amount N, and a determination is made as to whether or not the tension of the crawler belt 3e needs to be adjusted. Each determination is the same as that described in the first embodiment with reference to Figure 4. Note that, due to the execution of such parallel processing, steps S11 and S14 shown in Figure 10 have been omitted.

In steps S13, 15-17, the inspection results for the idler 3b and each carrier roller 3c are also displayed in parallel on the display 46. For example, messages such as "normal" for the idler 3b and front carrier roller 3c, "repair" for the rear carrier roller 3c, and "no tension adjustment required for the track 3e" are simultaneously displayed on the display 46, allowing the operator to determine whether maintenance is required for each item based on this display.

After the inspection results are displayed, step S18 determines "No" because the right side has not yet been inspected, and the routine proceeds to step S32. In step S32, the left drive units 52 and 57 are driven to switch the shielding plates 53 and 58 to the closed position, and in the following step S31, the right drive units 52 and 57 are driven to switch the shielding plates 53 and 58 to the open position. The guidance in the following step S2 instructs the right tracked traveling device 3 to be jacked up. Thereafter, the same processing as for the left side is executed, and when the determination in step S18 is "Yes," the routine proceeds to step S33, where the right drive units 52 and 57 are driven to switch the shielding plates 53 and 58 to the closed position. In the following step S19, as the termination work, guidance is given on the work content to stop jacking up the right tracked traveling device 3, and then the routine ends.
The tension and failure determination value update routine described with reference to FIG. 11 is also executed in the same manner as in the first embodiment.

As described above, according to this embodiment, the inspection process is performed by jacking up the track-type traveling device 3, so just like the first embodiment, the rotation amount N can be measured accurately without being affected by the ground, thereby obtaining accurate inspection results. Various associated effects can also be achieved in the same way as the first embodiment, although a redundant explanation will not be given here.

In addition, the rotation amount sensor 28 is disposed within the sensor housings 51, 56 defined in the yoke 21 and side frame 18, and the shielding plates 53, 58 are switched to the open position to enable detection of the reflectors 34, 41 only when inspection processing of the tracked traveling device 3 is required. Therefore, under normal circumstances, the rotation amount sensor 28 is disposed within the sensor housings 51, 56 and is protected from dust and other particles, thereby preventing malfunction of the rotation amount sensor 28 due to this.

Furthermore, during the inspection process, there is no need to attach or detach the rotation amount sensor 28 as in the first embodiment, and there is no need to connect or disconnect wiring to the controller 43, so the labor required for the inspection process can be reduced and it can be carried out easily. Furthermore, because the rotation amount sensors 28 are provided separately for the idler 3b and the front and rear carrier rollers 3c, the inspection processes for each can be carried out in parallel. Therefore, the time required for the inspection process can be shortened compared to the first embodiment, allowing the hydraulic excavator 1 to resume its original work sooner.

This concludes the description of the embodiment, but the aspects of the present invention are not limited to this embodiment. For example, in the above embodiment, the measured rotation amount N of the idler 3b and carrier roller 3c was used to determine their respective usage limits, the presence or absence of a malfunction, and the need for adjustment of the tension of the crawler belt 3e, but this is not limiting. Any of the inspection processes may be omitted, or new inspection processes may be added.

In addition, while the above embodiment inspects both the left and right track-type traveling units 3, this is not a limitation, and only one of the left and right may be inspected. For example, if the left track-type traveling unit 3 is inspected and its idler 3b reaches its service limit, not only the left idler 3b but also the right idler 3b that has been in a similar operating condition may be replaced; this type of inspection is also encompassed by the present invention.

In the above embodiment, the controller 43 guides the operator in jacking up and determines whether jacking up is complete based on the operation of the preparation complete button 45, but this is not limited to this. For example, the controller 43 may drive and control the hydraulic cylinders 6a to 8a of the swivel device 2a and the front work unit 5 to automatically perform jacking up (this corresponds to the "jacking up determination unit" in the present invention).

REFERENCE SIGNS LIST 1 Hydraulic excavator 2 Undercarriage 3 Tracked traveling device 3a Drive sprocket 3b Idler (driven roller)
3c Carrier roller (driven roller)
3e Track 4 Upper rotating body 5 Front work part 15 Track adjustment device 24 Stroke sensor (operation amount detection unit)
27 Master pin sensor (measurement section detection unit)
28 Rotation amount sensor (rotation state detection unit)
31, 32 Sensor fixing part (fixing part)
43 Controller (control device)
43a Wear amount estimation unit 43b Jack-up determination unit 43c Use limit determination unit 43d Tension adjustment determination unit 43e Failure determination unit 43f Failure determination value update unit 43g Tension determination value update unit 45 Preparation complete button 46 Display (display unit)
51, 56 Sensor housing (housing)
53,58 Shielding plate

Claims (14)

A hydraulic excavator in which a track-type traveling device is provided on each of the left and right sides of a lower traveling body, the track-type traveling device being formed by wrapping an endless track around a drive sprocket and a plurality of driven rollers, and an articulated work front is provided by rotatably connecting an upper rotating body to the lower traveling body,
a wear amount estimation unit that estimates the wear amount of the driven roller by driving at least one of the left and right tracked traveling devices as an inspection target;
a jack-up determination unit that determines a jack-up state in which the work front is brought into contact with the ground and the track-type traveling device to be inspected is separated from the ground;
a control device having
the wear amount estimation unit estimates the wear amount of the driven roller when the jack-up determination unit determines that the track-type traveling device to be inspected is in a jack-up state. the driven rollers include an idler whose position is displaced in the front-rear direction by a track adjustment device to adjust the tension of the track, and a plurality of rollers disposed between the drive sprocket and the idler;
2. The hydraulic excavator according to claim 1, wherein the wear amount estimating unit estimates the wear amount of at least one of the idler and each of the rollers. a rotation state detection unit that detects the rotation state of the driven roller;
3. The hydraulic excavator according to claim 2, wherein the wear amount estimating unit estimates the wear amount based on the rotation state of the driven roller detected by the rotation state detecting unit. a fixing portion provided at a position close to the driven roller of the lower traveling body,
4. The hydraulic excavator according to claim 3, wherein the rotation state detection unit is detachably fixed to the fixed part so as to be able to detect the rotation state of the driven roller. a storage section defined in a position adjacent to the driven roller of the lower traveling body and isolated from the outside when an openable and closable shielding plate is in a closed position;
4. The hydraulic excavator according to claim 3, wherein the rotation state detection unit is disposed in the accommodation unit and is capable of detecting the rotation state of the driven roller when the shielding plate is switched to the open position. a measurement section detection unit that detects driving of the crawler belt in a predetermined measurement section,
the rotation state detection unit is configured as a rotation amount sensor that measures a rotation amount as a rotation state of the driven roller,
4. The hydraulic excavator according to claim 3, wherein the wear amount estimating unit determines the amount of rotation measured by the rotation amount sensor in the measurement section detected by the measurement section detecting unit as the amount of wear of the driven roller. an operation amount detection unit that detects an operation amount of the track adjustment device that correlates with the length of the track;
7. The hydraulic excavator according to claim 6, wherein the wear amount estimating unit corrects the amount of rotation measured by the rotation amount sensor based on the amount of operation of the track adjuster detected by the operation amount detecting unit. a use limit determination unit that determines a use limit of the driven roller;
8. The hydraulic excavator according to claim 6, wherein the service limit determination unit determines that the driven roller has reached its service limit when the amount of rotation of the driven roller estimated as the amount of wear by the wear amount estimation unit becomes equal to or greater than a predetermined replacement determination value. a tension adjustment determination unit that determines whether or not tension adjustment of the crawler belt is required;
9. The hydraulic excavator according to claim 8, wherein the tension adjustment determination unit determines that adjustment of the tension of the crawler is required when the rotation amount of the driven roller estimated as the amount of wear by the wear amount estimation unit becomes equal to or greater than a preset tension determination value. a failure determination unit that determines whether or not the driven roller has a failure;
10. The hydraulic excavator according to claim 9, wherein the failure determination unit determines that a failure has occurred in the driven roller when the amount of rotation of the driven roller estimated as the amount of wear by the wear amount estimation unit becomes equal to or less than a preset failure determination value. 11. The hydraulic excavator according to claim 9 or 10, further comprising a tension determination value update unit that updates the tension determination value by adding a preset increment to the tension determination value when the track tension is adjusted by the track adjustment device based on the determination by the tension adjustment determination unit. 11. The hydraulic excavator according to claim 10, further comprising a failure determination value update unit that updates the failure determination value by subtracting a preset decrease amount from the failure determination value when the track tension is adjusted by the track adjustment device based on the determination of the tension adjustment determination unit. A display that can be seen by the operator of the hydraulic excavator,
a ready button for inputting completion of the jacking up;
Furthermore,
The hydraulic excavator according to any one of claims 1 to 12, wherein the jack-up determination unit instructs the operator to jack up using the display unit, and determines that the excavator is in the jack-up state when the preparation complete button is operated thereafter. 14. The hydraulic excavator according to claim 1, wherein the wear amount estimating unit inspects both of the left and right track-type traveling devices.