Rotating structure and work machine equipped therewith

Abstract

This invention provides a rotating structure that can accurately detect the rotational state of a swing bracket. [Solution] The rotating structure comprises a base, a person to be detected fixed to the base, a pivot supported by the base so as to be rotatable around its axis, a swing bracket attached to the base via the pivot and rotating together with the pivot so as to be rotatable relative to the base, a sensor for detecting the person to be detected, and a sensor bracket that supports the sensor and is fastened to the swing bracket.

Description

Technical Field

[0001] The present invention relates to a rotating structure that rotatably supports a working device, and a working machine having the rotating structure.

Background Art

[0002] Conventionally, a working machine having a swing function for rotating a working device composed of a boom, an arm, a bucket, etc. around a vertical pivot (swing pin) is known. Further, among working machines having a swing function, some are provided with a detection device for detecting the swing state. For example, Patent Document 1 discloses a technique for detecting a swing state by detecting a detected object with a non-contact sensor, which includes a support bracket, a swing bracket rotatably supported by the support bracket, a non-contact sensor attached to the swing bracket, and a detected object attached to the support bracket.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique of Patent Document 1, since the non-contact sensor is attached to the swing pin, the sensing accuracy may vary due to the play above and below the swing pin.

[0005] An object of the present invention is to provide a rotating structure capable of solving the above problems and a working machine having the same.

Means for Solving the Problems

[0006] A rotating structure according to one aspect of the present invention comprises a base portion, a detectable object fixed to the base portion, a pivot supported by the base portion so as to be rotatable about an axis, a swing bracket attached to the base portion via the pivot and so as to be rotatable relative to the base portion by rotating together with the pivot, a sensor for detecting the detectable object, and a sensor bracket that supports the sensor and is fastened to the swing bracket. [Effects of the Invention]

[0007] The sensor bracket supporting the sensor can be easily and securely fastened to the swing bracket while restricting both relative rotation around the pivot axis and relative movement in the axial direction, thus easily stabilizing the positional relationship between the sensor and the object being detected (stabilizing the sensor's sensitivity). Therefore, it is possible to provide a rotating structure that can accurately detect the rotational state of the swing bracket. [Brief explanation of the drawing]

[0008] [Figure 1] This is a left side view of a rotary excavating machine (hereinafter simply referred to as "the machine"). [Figure 2] This is a plan view of the aforementioned work machine. [Figure 3] This is an enlarged plan view showing the front of the machine body of the aforementioned work machine, with the canopy, swing bracket, and work equipment omitted. [Figure 4] This is a right front perspective view of the main frame, which has a rotating structure with the sensor cover omitted. [Figure 5] This is an upper right perspective view of the rotating structure. [Figure 6] This is a left rear upper perspective view of the rotating structure. [Figure 7A] This is a partially enlarged perspective view showing the main part of the rotating structure with the sensor cover removed. [Figure 7B] This is a partially enlarged perspective view showing the main parts of the rotating structure, with the sensor cover, swing pin, and anti-rotation arm removed. [Figure 7C] This is a partially enlarged perspective view showing the main parts of the rotating structure, excluding the detection device, swing pin, and anti-rotation arm. [Figure 8A] It is a partially enlarged rear view showing the main part of the rotating structure. [Figure 8B] It is a partially enlarged rear view showing the main part of the rotating structure with the sensor cover omitted. [Figure 8C] It is a partially enlarged rear view showing the main part of the rotating structure with the sensor cover, swing pin and anti-rotation arm omitted. [Figure 9A] It is a partially enlarged rear view showing the main part of the rotating structure with the sensor cover omitted. [Figure 9B] It is a partially enlarged rear view showing the main part of the rotating structure with the sensor cover, swing pin and anti-rotation arm omitted. [Figure 10] It is a sectional view taken along the line X-X of FIG. 8B showing the main part of the rotating structure with the sensor cover omitted. [Figure 11] It is a sectional view taken along the line XI-XI of FIG. 8B showing the main part of the rotating structure with the sensor cover omitted. [Figure 12] It is a perspective view of the sensor bracket. [Figure 13] It is a block diagram showing the swing control system.

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] First, referring to FIGS. 1 to 6 and the like, the configuration of a swing-type excavator 1 (hereinafter simply referred to as "working machine 1") as an example of a working machine provided with a rotating structure 40 according to the present invention will be described.

[0010] FIG. 1 is a left side view of the working machine 1. FIG. 2 is a plan view of the working machine 1. FIG. 3 is an enlarged plan view showing the front part of the machine body 20 in the working machine 1 with the canopy 27, swing bracket 42, working device 30 and the like omitted. FIG. 4 is a right front perspective view of the main body frame 21 provided with the rotating structure 40 with the sensor cover 48 omitted. FIG. 5 is a right upper perspective view of the rotating structure 40. FIG. 6 is a left rear upper perspective view of the rotating structure 40.

[0011] As shown in FIG. 1, FIG. 2, etc., the work machine 1 includes a traveling body 10, a machine body 20, and a working device 30.

[0012] The machine body 20 is mounted on the upper part of the traveling body 10 (specifically, the traveling frame 11 described later) via a swivel axis (swivel joint). This swivel axis has a vertical axis core Xv (hereinafter, “swivel axis core Xv”) as shown in FIGS. 1 and 4, and the machine body 20 can rotate relative to the traveling body 10 in the horizontal direction (swivel) around the swivel axis core Xv.

[0013] Also, as shown in FIG. 1, the entire working device 30 including a boom 31, an arm 32, a bucket 33, etc. is supported by the machine body 20 via a rotating structure 40. The rotating structure 40 includes a pivot (swing pin 41) having a vertical axis core Y (hereinafter, “swing axis core Y”) as shown in FIGS. 1, FIGS. 4 to 6, etc. The entire working device 30 can rotate relative to the machine body 20 in the horizontal direction (swing) around the swing axis core Y.

[0014] In the description of each component of the following work machine 1, the “front-rear direction” is the direction that coincides with the front-rear direction of the machine body 20, which is constant regardless of the relative rotational position of the traveling body 10 with respect to the machine body 20 around the swivel axis core Xv. The front-rear direction of the machine body 20, for the machine body 20 (main body frame 21) depicted in FIGS. 1 to 6, is the direction along the bidirectional arrow A1 shown in FIGS. 1, FIGS. 2, and FIG. 6 (hereinafter, referred to as “front-rear direction A1”).

[0015] Also, in the description of each component of the following work machine 1, the direction of “front” or “front side” for the said component corresponds to the direction pointed by the unidirectional arrow A2 along the front-rear direction A1 of the machine body 20 as shown in FIGS. 1 to 6, and the direction of “rear” or “rear side” for the said component corresponds to the direction pointed by the other unidirectional arrow A3 along the front-rear direction A1 of the machine body 20 as shown in FIGS. 1, FIGS. 2, FIGS. 4 to 6.

[0016] In other words, in some of the drawings from Figures 5 to 11, which will be referenced later when explaining the configuration of the rotating structure 40, arrow A2 is depicted as indicating the "forward" or "front side" direction for the rotating structure 40, and arrow A3 is depicted as indicating the "rear" or "backside" direction for the rotating structure 40.

[0017] Furthermore, in the following descriptions of each component of the work machine 1, "left-right direction" refers to the direction that coincides with the left-right direction (width direction) of the machine body 20, which is constant regardless of the relative rotational position of the traveling body 10 with respect to the machine body 20 around the pivot axis Xv. The left-right direction of the machine body 20 refers to the direction along the bidirectional arrow B1 shown in Figures 2 and 6 for the machine body 20 (main frame 21) as depicted in Figures 2 to 6 (hereinafter referred to as "left-right direction B1").

[0018] Furthermore, in the following descriptions of each component of the work machine 1, the "left" or "left side" direction for that component corresponds to the direction pointed to by the unidirectional arrow B2 along the left-right direction B1 of the machine body 20, as shown in Figures 2 to 6, and the "right" or "right side" direction for that component corresponds to the direction pointed to by the other-directional arrow B3 along the left-right direction B1 of the machine body 20, as shown in Figures 2 to 6.

[0019] In other words, in some of the drawings from Figures 5 to 11, which will be referenced later when explaining the configuration of the rotating structure 40, arrow B2 is depicted as indicating the "left" or "left side" direction relative to the rotating structure 40, and arrow B3 is depicted as indicating the "right" or "right side" direction relative to the rotating structure 40.

[0020] The configuration of the traveling body 10 of the work machine 1 will be explained using Figures 1 to 3. Figures 1 to 3 show the work machine 1 in a state where the front-rear direction of the traveling body 10 coincides with the front-rear direction of the machine body 20, and the following explanation of the traveling body 10 will be based on the assumption that the work machine 1 is in this state.

[0021] The traveling body 10 has a traveling frame 11 and a pair of traveling devices 12 on the left and right sides. Of the pair of traveling devices 12, one is a left traveling device 12L provided on the left side of the traveling frame 11, and the other is a right traveling device 12R provided on the right side of the traveling frame 11.

[0022] In this embodiment, the running gear 12 is a crawler-type running gear in which crawlers are wrapped around drive wheels, idler wheels, etc., supported on a track frame. However, it may also be a tire-type running gear with a different configuration from the crawler-type running gear, for example, a tire-type running gear that does not have crawlers but has tires as front and rear wheels.

[0023] Furthermore, as shown in Figures 1 to 3, a dozer 13 is provided at the front of the traveling body 10. The dozer 13 has blades 13a positioned in front of a pair of left and right traveling devices 12, and actuators (hydraulic cylinders) 13b for swinging the blades up and down.

[0024] The configuration of the machine body 20 of the work machine 1 will be explained with reference to Figures 1 to 5. The machine body 20 consists of a main frame (chassis) 21 as shown in Figures 3 to 5, a lower side cover 22 erected along the peripheral edge from the left front to the left end of the main frame 21 as shown in Figures 1 and 2, a counterweight 23 mounted on the rear end of the main frame 21 as shown in Figure 1, a rear bonnet 24 mounted on the rear of the main frame 21 via the counterweight 23 and forming the rear of the machine body 20 as shown in Figure 1, and a side bonnet 25 mounted on the right side of the main frame 21 and forming the right side of the machine body 20 as shown in Figure 2.

[0025] Various devices for driving (operating) the running gear 12 and the work gear 30 are installed on the machine body 20 configured in this way. For example, an internal combustion engine as a prime mover is mounted at the rear of the main frame 21 and covered by a rear bonnet 24, and a fuel tank, hydraulic oil tank, battery, etc. are mounted on the right side of the main frame 21 and covered by a side bonnet 25.

[0026] As shown in Figures 1 to 5, the driver's seat 26 is mounted near the front of the rear bonnet 24 and near the left of the side bonnet 25. As shown in Figures 1, 4, and 5, the left wall of the side bonnet 25 is an operation panel 25a located to the right of the driver's seat 26, and various switches and other operating devices are provided on the operation panel 25a.

[0027] Furthermore, as shown in Figures 1 and 2, the aircraft body 20 is provided with a canopy 27. The canopy 27 has canopy pillars 27a and a roof 27b. A pair of left and right canopy pillars 27a are erected from the upper surface of the rear bonnet 24 behind the driver's seat 26. The roof 27b extends forward from the upper ends of the pair of left and right canopy pillars 27a so as to cover the driver's seat 26 from above.

[0028] As shown in Figures 1 to 3, a floor plate 28 is laid along the upper edge of the lower side cover 22, extending from the front to the left of the driver's seat 26. The operator seated in the driver's seat 26 can see the external space in front of (A2) and to the left of (B2, B3) the machine body 20 through the open space above the floor plate 28, and in particular can visually check the condition of the work device 30 and the rotating structure 40 located in front of (A2) the machine body 20.

[0029] As shown in Figures 1 to 3, the consoles on the left and right sides of the driver's seat 26, behind the floorboard 28, are equipped with work operation levers 61 that can be manually operated by an operator seated in the driver's seat 26. In this embodiment, a pair of left and right work operation levers 61 are provided; one is the left work operation lever 61L located on the left side of the driver's seat 26, and the other is the right work operation lever 61R located on the right side of the driver's seat 26.

[0030] The work operation levers 61 (left and right work operation levers 61L and 61R) are operable levers for controlling the movement of the boom 31, arm 32, and bucket 33 of the work device 30 (i.e., the extension and retraction of the boom cylinder 34, arm cylinder 35, and bucket cylinder 36).

[0031] Furthermore, as shown in Figures 1 and 2, an operating lever 62 that can be manually operated by an operator seated in the driver's seat 26, and an operating pedal 63 that can be operated by the operator stepping on it with their foot are provided at appropriate positions on the floorboard 28 in front of the driver's seat 26.

[0032] In this embodiment, a pair of left and right travel control levers 62 are provided to control the travel direction and travel speed of the left and right travel devices 12 separately. Specifically, one of the pair of left and right travel control levers 62 is the left travel control lever 62L for controlling the travel direction and travel speed of the left travel device 12L, and the other is the right travel control lever 62R for controlling the travel direction and travel speed of the right travel device 12R.

[0033] In addition, in this embodiment, a pair of operating pedals 63 are also provided, one on the left and one on the right. For example, one of the operating pedals 63 (the left operating pedal 63 in this embodiment) is used to rotate (oscillate) the work device 30 (swing bracket 42) around the swing axis Y (i.e., the swing described below). This is the swing pedal 63a for extending and retracting the cylinder 39. The other of the operating pedals 63 (the right operating pedal 63 in this embodiment) is the AUX pedal 63b for driving an auxiliary (AUX) attachment mounted on the tip of the arm 32 in place of (or in addition to) the bucket 33 (i.e., for controlling the supply and discharge of hydraulic fluid to the AUX port 38 described later).

[0034] Furthermore, as shown in Figures 1 and 2, safety fences 64 and 65, which also serve as handrails, are erected along the left and front edges of the floorboard 28. As shown in Figure 1, a column 66 is erected to the right of the safety fence 65 along the front edge of the floorboard 28, and a display device 67, as shown in Figures 1 and 2, is provided at the upper end of the column 66.

[0035] The display device 67 functions as both an output interface (instrument panel) that displays detection results from various sensors installed on the work machine 1 and the current setting status based on the operation of switches, etc., and an input interface (operation panel) that allows the operator to input setting values ​​for various operations. The switches and other operating devices that the operator can operate may be images displayed on the screen of the display device 67, or physical devices attached to the display device 67.

[0036] For example, the work machine 1 is configured to allow selection of two operating modes for the work device 30: an excavation mode in which excavation work is performed using the bucket 33 described later, or a crane mode in which the work device 30 is operated as a crane for lifting materials. The operator can select the mode using the display device 67, and the display device 67 can display the mode set by such selection operation.

[0037] The central part of the main frame 21 shown in Figure 4 is pivotally supported by the travel frame 11 located below it via the aforementioned swivel joint having a pivot axis Xv.

[0038] Furthermore, as shown in Figures 2 to 5, a swing cylinder (actuator) 39 is positioned in the space between the main frame 21 and the floor plate 28 above it. As shown in Figure 4, the base end (cylinder bottom) of the swing cylinder 39 is pivotally supported by a cylinder bracket portion 21a formed on the right side of the main frame 21. Also, as shown in Figure 5 and other figures, the tip end (cylinder head) of the swing cylinder 39 is pivotally supported by a cylinder bracket portion 42e formed on the right side of the swing bracket 42, which will be described later.

[0039] As shown in Figures 1 to 6, the front part of the main frame 21 protrudes forward beyond the front end of the floor plate 28, and this forward protrusion is formed as a base portion 29. A swing bracket 42 is attached to this base portion 29 via a swing pin (pivot) 41 having the aforementioned vertical swing axis Y, as shown in Figures 1, 3 to 6.

[0040] These base portion 29, swing pin 41, swing bracket 42, etc., constitute a rotating structure 40 that supports the entire working device 30 on the machine body 20 (main frame 21) and allows it to rotate (oscillate) relative to the machine body 20 around the swing axis Y, as described above. The specific configuration of the rotating structure 40 will be described in detail later.

[0041] Figures 1 and 2 illustrate the configuration of the working device 30 of the work machine 1. The working device 30 of the work machine 1, which is an excavation work machine (backhoe), has a boom 31, an arm 32, and a bucket 33, as described above.

[0042] As shown in Figure 1, the boom 31 is bent in the middle of its longitudinal direction, and the base end of the boom 31 on one side of the bend is pivotally supported by a boom bracket portion 42c formed on the upper part of the swing bracket 42 via a horizontal boom pivot 31a, allowing it to rotate up and down. It is being done.

[0043] Furthermore, the base end of an arm 32 is pivotally supported at the tip of the boom 31 on the other side of the bent portion of the boom 31 via a horizontal arm pivot 32a, allowing it to rotate vertically. A bucket 33 is pivotally attached to the tip of the arm 32.

[0044] Furthermore, as shown in Figures 1 and 2, the work device 30 includes a boom cylinder 34, which is a hydraulic actuator for the boom 31; an arm cylinder 35, which is a hydraulic actuator for the arm 32; and a bucket cylinder 36, which is a hydraulic actuator for the bucket 33.

[0045] As shown in Figure 1, the base end (cylinder bottom) of the boom cylinder 34 is pivotally supported by the cylinder bracket portion 42d formed on the swing bracket 42. When the swing bracket 42 is in the default position D (see Figure 6, etc.) described later in the rotational direction around the swing pin 41, the cylinder bracket portion 42d is formed at the front end of the swing bracket 42 in the front-rear direction A1 of the machine body 20 (the tip portion on the side of arrow A2 in Figures 1 to 6 for the swing bracket 42).

[0046] As shown in Figure 1, a cylinder bracket portion 31b is formed on one side of the bent portion of the boom 31, and the tip portion (cylinder head) of the boom cylinder 34 is pivotally supported by the cylinder bracket portion 31b. Thus, the boom 31 rotates around the boom pivot 31a relative to the swing bracket 42 (machine body 20) by the extension and retraction of the boom cylinder 34 interposed between the swing bracket 42 and the boom 31.

[0047] As shown in Figure 1, the base end (cylinder bottom) of the arm cylinder 35 is pivotally supported by a cylinder bracket portion 31c formed on the other side of the bent portion of the boom 31. Similarly, the tip (cylinder head) of the arm cylinder 35 is pivotally supported by a cylinder bracket portion 32b formed on the base end of the arm 32. Thus, the extension and retraction of the arm cylinder 35, interposed between the boom 31 and the arm 32, causes the arm 32 to rotate relative to the boom 31 around the arm pivot 32a.

[0048] As shown in Figure 1, the base end (cylinder bottom) of the bucket cylinder 36 is further pivotally supported on the cylinder bracket portion 32b of the arm 32. The tip (cylinder head) of the arm cylinder 35 is pivotally connected to the tip of the arm 32 and the bucket 33 via the bucket link 33a. As the bucket cylinder 36 interposed between the arm 32 and the bucket 33 extends and retracts, the bucket link 33a acts, causing the bucket 33 to swing relative to the arm 32 in the scooping direction C1 and the dumping direction C2.

[0049] Furthermore, as shown in Figures 1 and 2, the boom 31 and arm 32 are equipped with hydraulic fluid piping for the boom cylinder 34, arm cylinder 35, and bucket cylinder 36, as well as piping for supplying and discharging hydraulic fluid to an AUX attachment mounted on the tip of the arm 32 in place of (or in addition to) the bucket 33. The tip of this piping is located on the side of the arm 32 as an AUX port (coupler) 38.

[0050] Furthermore, as shown in Figures 1 and 2, the bucket 33 is equipped with a hook 37 for lifting loads. Normally (during excavation work, etc.), this hook 37 is stored locked in the bucket 33. The hook 37 can be released by rotating the bucket 33 in the scooping direction C1 relative to the arm 32, thereby lowering it below the bucket 33 (by removing the locking pin, etc.). When the crane mode is set as described above, a load can be attached to the lowered hook 37, and the boom 31 and / or arm 32 can be operated to lift (crane) the load.

[0051] When crane mode is set, rotation (oscillation) of the work device 30 around the swing axis Y is restricted or prohibited to ensure safety when operating the boom 31 and arm 32 as a crane. Therefore, as shown in Figures 1 and 6, the rotating structure 40 is equipped with a detection device 40s that can perform detection related to the rotation of the swing bracket 42 around the swing axis Y (such as detection of the rotation angle of the swing bracket 42, or detection of whether the swing bracket 42 is in a predetermined rotation position (range)).

[0052] In this embodiment, the detection device 40s detects whether the swing bracket 42 is in a predetermined rotational position, which is the default position D (see Figure 8, etc.), and consists of a detected object 49 (described later) and a sensor 47 that detects the presence or absence of the detected object 49.

[0053] Furthermore, the work machine 1 is equipped with a control system to restrict (prohibit) the rotation (oscillation) of the work device 30 around the swing axis Y when crane mode is set. Figure 13 is a block diagram showing such a control system, the swing control system 100. The swing control system 100 shown in Figure 13 will now be explained.

[0054] The work machine 1 is equipped with a control device 101 consisting of an integrated circuit programmed for the construction of the system. The swing control system 100 consists of the control device 101, a detection device 40s, a display device 67, and a control valve 102 electrically connected to the control device 101, and a swing cylinder (actuator) 39 fluidly connected to the control valve 102. The control valve 102 is a structure that can be electromagnetically controlled in position by an electrical signal from the control device 101 (for example, an electromagnetic proportional valve), and the extension and retraction of the swing cylinder 39 is controlled by changing the position of the control valve 102.

[0055] When an operator sets the crane mode by using the display device 67 as an input interface, a crane mode signal Sc indicating that the crane mode has been set is input to the control device 101 via the display device 67.

[0056] While the control device 101 is receiving the crane mode signal Sc from the display device 67, it receives a default determination signal Sd indicating the detection result of the detection device 40s. Based on the default determination signal Sd, the control device 101 determines whether the swing bracket 42 is in the default position D, and sends an image output signal Se to the display device 67, which acts as an output interface, to display the determination result on the display device 67, or, in some cases, to display a warning image.

[0057] Then, while the control device 101 is receiving the crane mode signal Sc from the display device 67, if it determines that the swing bracket 42 is in the default position D based on the default determination signal Sd received from the detection device 40s, it then sends a control signal Sf to the control valve 102 while it is receiving the crane mode signal Sc, thereby maintaining the position of the control valve 102 at the time of the determination and restricting the extension and retraction of the swing cylinder 39.

[0058] Furthermore, if the control device 101 determines that the swing bracket 42 is not in the default position D when the crane mode is set, it prompts the operator to perform an operation to rotate (oscillate) the swing bracket 42 to the default position D (for example, by pressing the swing pedal 63a as described above) by displaying a warning screen on the display device 67.

[0059] As mentioned above, the work machine 1 according to this embodiment is equipped with a swing pedal 63a as an operating member that can be operated by the operator to rotate (oscillate) the swing bracket 42 (i.e., to operate the control valve 102 to extend and retract the swing cylinder 39). Therefore, a locking mechanism may be provided on the swing pedal 63a to lock the swing bracket 42 to the default position D when the crane mode is set.

[0060] In this case, for example, the control device 101 may lock the swing pedal 63a to the neutral position corresponding to the default position D of the swing bracket 42 by activating the lock mechanism as soon as it receives a crane mode signal Sc from the display device 67, which serves as an input interface, and a default determination signal Sd from the detection device 40s. The control device 101 may perform the control of the lock mechanism that locks the swing pedal 63a in this manner in addition to, or instead of, outputting a control signal Sf to the control valve 102 as described above.

[0061] Alternatively, for example, if the work machine 1 is equipped with a potentiometer or the like in addition to the detection device 40s to detect the actual rotation (oscillation) position of the swing bracket 42 around the swing axis Y, the control device 101 may, when setting the crane mode, determine that the swing bracket 42 is not in the default position D, output a command signal for changing the position to the control valve V based on the signal indicating the actual rotation (oscillation) position of the swing bracket 42 received from the potentiometer or the like, and extend or retract the swing cylinder 39 to rotate (oscillate) the swing bracket 42 to the default position D.

[0062] The specific configuration of the rotating structure 40, including the detection device 40s, will be described in detail below, with reference to Figures 1 to 6 and 13, as well as Figures 7A to 12, etc.

[0063] Figure 7A is a partially enlarged perspective view showing the main part of the rotating structure 40 with the sensor cover 48 omitted. Figure 7B is a partially enlarged perspective view showing the main part of the rotating structure 40 with the sensor cover 48, swing pin 41, and anti-rotation arm 43 omitted. Figure 7C is a partially enlarged perspective view showing the main part of the rotating structure 40 with the detection device 40s, swing pin 41, and anti-rotation arm 43 omitted.

[0064] Figure 8A is a partially enlarged rear view showing the main part of the rotating structure 40. Figure 8B is a partially enlarged rear view showing the main part of the rotating structure 40 with the sensor cover 48 omitted. Figure 8C is a partially enlarged rear view showing the main part of the rotating structure 40 with the sensor cover 48, swing pin 41, and anti-rotation arm 43 omitted.

[0065] Figure 9A is a partially enlarged rear view showing the main parts of the rotating structure 40 with the sensor cover 48 omitted. Figure 9B is a partially enlarged rear view showing the main parts of the rotating structure 40 with the sensor cover 48, swing pin 41, and anti-rotation arm 43 omitted.

[0066] Figure 10 is a cross-sectional view taken along the line X-X in Figure 8B, showing the main part of the rotating structure 40 with the sensor cover 48 omitted. Figure 11 is a cross-sectional view taken along the line XI-XI in Figure 10B, showing the main part of the rotating structure 40 with the sensor cover 48 omitted. Figure 12 is a perspective view of the sensor bracket 44.

[0067] The rotating structure 40 comprises a base portion 29, a detected object 49 fixed to the base portion 29, a swing pin (pivot) 41 rotatably supported by the base portion 29 around the swing axis Y, a swing bracket 42 attached to the base portion 29 via the swing pin 41 and rotatably relative to the base portion 29 by rotating together with the swing pin 41, a sensor 47 for detecting the detected object 49, and a sensor bracket 44 that supports the sensor 47 and is fastened to the swing bracket 42.

[0068] Furthermore, this rotating structure 40 has a rotation-preventing arm fixed to the swing pin 41 (rotation The device includes a fastening member 43 and a sensor bracket 44 that fastens to the swing bracket 42, as well as a fastening mechanism 50 that restricts the rotation of the anti-rotation arm 43 around the swing axis Y relative to the swing bracket 42.

[0069] The fastening mechanism 50 includes a boss (cylindrical portion) 45 fixed to the sensor bracket 44, and a bolt (fastening member) 46 that is inserted through the boss 45 and attached to the swing bracket 42, thereby fastening the sensor bracket 44 to the swing bracket 42.

[0070] The boss 45 is inserted through the anti-rotation arm 43 and attached to the swing bracket 42 by bolts 46, thereby restricting the relative rotation of the anti-rotation arm 43 with respect to the swing bracket 42 around the swing axis Y.

[0071] The boss 45 may be integrally molded with the sensor bracket 44.

[0072] The overall configuration of the rotating structure 40 is as described above. Next, the specific configurations of each component that makes up the rotating structure 40 will be explained.

[0073] The main elements of the rotating structure 40 are the base portion 29 of the machine body 20, the swing bracket 42 that supports the working device 30, and the swing pin 41 that pivotally supports the swing bracket 42 to the base portion 29.

[0074] As shown in Figures 3, 7C, 10, and 11, a cylindrical boss 29a is formed at the front end of the base portion 29, having a vertically penetrating boss hole 29b. A cylindrical or columnar swing pin 41 is inserted through the boss hole 29b, and the axis of the boss hole 29b and the axis of the swing pin 41 coincide to define the vertical swing axis Y.

[0075] As shown in Figures 10 and 11, the outer circumferential surface of the swing pin 41 and the inner circumferential surface of the boss 29a that defines the boss hole 29b are in relative sliding contact via the bush (radial bearing) 41a. As a result, the swing pin 41 can rotate (oscillate) relative to the base portion 29 (machine body 20) about the swing axis Y, and can also move (slide) relative to the swing axis Y direction (vertical direction).

[0076] As shown in Figures 1, 4 to 6, 7C, etc., the swing bracket 42 has an upper clamping portion 42a and a lower clamping portion 42b (hereinafter sometimes referred to as "upper and lower clamping portions 42a and 42b") that extend horizontally on one horizontal side, with the upper clamping portion 42a positioned above the base portion 29 and the lower clamping portion 42b positioned below the base portion 29.

[0077] As shown in Figures 1, 4-6, 7C, etc., the aforementioned cylinder bracket portion 42d, which pivotally supports the base end of the boom cylinder 34, is formed on the other horizontal side of the swing bracket 42 opposite to the upper and lower clamping portions 42a and 42b.

[0078] As mentioned above, a default position D is set for the rotation (oscillation) of the swing bracket 42 around the swing axis Y relative to the base portion 29, and Figures 4 to 11 all show the rotating structure 40 when the swing bracket 42 is in the default position D.

[0079] Thus, when the swing bracket 42 is in the default position D, the horizontal side of the swing bracket 42 where the upper and lower clamping portions 42a and 42b are formed is the rear side of the machine body 20 in the front-rear direction A1 (see arrow A3 in Figures 4 to 7C and 9A to 11), and the horizontal side of the swing bracket 42 where the cylinder bracket portion 42d is formed is This refers to the front side of the aircraft 20 in the longitudinal direction A1 (see arrow A2 in Figures 4-6, 7C, 9A, 9B, and 11).

[0080] In other words, as shown in Figures 5 and 6, the orientation of the swing bracket 42 in the default position D is such that the upper and lower clamping portions 42a and 42b face rearward (A3), and the cylinder bracket portion 42d faces forward (A2).

[0081] The bottom of the swing pin 41 is inserted through a vertically through pin hole formed in the lower clamping portion 42b below the base portion 29, and the upper part of the swing pin 41 is inserted through a vertically through pin hole 42a1 formed in the upper clamping portion 42a above the base portion 29, via bushings 41a or the like as shown in Figures 10 and 11, so as to be able to rotate (oscillate) relative to the swing axis Y and move relative to the direction of the swing axis Y.

[0082] As shown in Figures 10 and 11, the upper end of the swing pin 41 protrudes above the upper clamping portion 42a, and a rotation-preventing arm (rotation-preventing member) 43 is fixed to the upper end of the swing pin 41.

[0083] Furthermore, the anti-rotation arm 43 only needs to be fixed to the swing pin 41. In other words, the anti-rotation arm 43 only needs to be immobile relative to the swing pin 41 in any direction (or at least in the direction around the swing axis Y and in the direction of the swing axis Y).

[0084] The anti-rotation arm 43 may, for example, be originally a separate component from the swing pin 41 and fixed to the upper end of the swing pin 41 by welding or pinning, or it may be molded integrally with the swing pin 41 from the beginning.

[0085] Furthermore, in this embodiment, the anti-rotation arm 43 is provided so as to surround the outer circumferential surface of the swing pin 41 in a flange-like manner, but the embodiment is not limited to this. For example, when the swing bracket 42 is in the default position D, the front end of the anti-rotation arm 43 may be connected only to the portion that becomes the rear end of the swing pin 41.

[0086] As shown in Figures 5, 6, 7A, 10, and 11, the anti-rotation arm 43 is a plate-shaped member that extends along the upper surface of the upper clamping portion 42a (radially in the direction of the swing pin 41) from the portion fixed to the upper end of the swing pin 41 to its tip edge 43a. The tip edge 43a of the anti-rotation arm 43 is positioned along the tip edge 42a2 of the upper clamping portion 42a. As shown in Figure 10, a vertically through hole 43b for inserting the boss 45 is formed near the tip edge 43a of the anti-rotation arm 43.

[0087] As shown in the above drawing, when the swing bracket 42 is in the default position D, the tip edge 43a corresponds to the rear end edge of the anti-rotation arm 43, and the tip edge 42a2 corresponds to the rear end edge of the upper clamping portion 42a. In other words, the tip edge 43a of the anti-rotation arm 43 and the tip edge 42a2 of the upper clamping portion 42a are positioned behind the swing pin 41 (towards the side of arrow A3).

[0088] As shown in Figures 5 to 11 (excluding Figures 7B, 7C, and 8C), a sensor bracket 44 having the structure (shape) shown in Figure 12 is positioned above the anti-rotation arm 43. The rotating structure 40 is equipped with a fastening mechanism 50 that fastens the sensor bracket 44 to the swing bracket 42. This fastening mechanism 50 restricts the rotation of the anti-rotation arm 43 around the swing axis Y relative to the swing bracket 42.

[0089] The fastening mechanism 50 comprises a boss (cylindrical portion) 45 and a bolt (fastening member) 46. The boss 45 is fixed to the sensor bracket 44, and the bolt 46 is inserted through the boss 45 and attached to the swing bracket 42, thereby fastening the sensor bracket 44 to the swing bracket 42.

[0090] The boss 45 hangs down from the bottom plate portion 44b formed on the sensor bracket 44 and is inserted through the hole 43b of the anti-rotation arm 43. The boss 45 and the hole 43c are approximately the same diameter, and the outer surface of the boss 45 and the inner surface of the hole 43b are in close contact, so there is no room in the hole 43b for the boss 45 to move relative to the anti-rotation arm 43 in the horizontal direction (radial direction of the boss 45).

[0091] Preferably, the anti-rotation arm 43 is formed so that a plurality of holes (two in this embodiment) 43b are arranged in the direction around the swing axis Y. Correspondingly, the anti-rotation arm 43 is provided with the same number of bosses 45 as the holes 43b (two in this embodiment). By having the plurality of bosses 45 inserted through their respective holes 43b, the relative rotation of the anti-rotation arm 43 and the sensor bracket 44 around the swing axis Y is more reliably restricted.

[0092] The tip edge 43a of the anti-rotation arm 43 has a width approximately in the direction around the swing axis Y, corresponding to the plurality of holes 43b. Therefore, when viewed in the direction along the swing axis Y (up and down direction), the anti-rotation arm 43 is formed in a U-shape with an open rear. However, the shape of the anti-rotation arm 43 is not limited to this. For example, if the anti-rotation arm 43 has two holes 43b, the anti-rotation arm 43 may be formed in a bifurcated shape, with the portion fixed to the swing pin 41 leading to the two holes 43b.

[0093] The boss 45 only needs to be fixed to the sensor bracket 44, that is, it should be immovable relative to the sensor bracket 44 in any direction (at least around the swing axis Y and in the direction of the swing axis Y). The boss 45 may be, for example, originally a separate component from the sensor bracket 44 and its upper part fixed to the bottom plate portion 44b of the sensor bracket 44 by welding or an anti-rotation pin, or it may be molded integrally with the sensor bracket 44 from the beginning.

[0094] The structure of the sensor bracket 44 shown in Figure 12, etc., will be described in detail. The sensor bracket 44 has a vertical plate-shaped main body portion 44a that extends in the vertical direction. A horizontal plate-shaped bottom plate portion 44b extends horizontally from the bottom end of the main body portion 44a, and this bottom plate portion 44b is fixed to the upper or lower part or upper part of the boss 45. That is, the boss 45 hangs down from the bottom plate portion 44b.

[0095] In this embodiment, corresponding to the provision of two bosses 45, the sensor bracket 44 is provided with two bottom plate portions 44b, and each boss 45 is fixed to each bottom plate portion 44b. The lower part of the main body portion 44a of the sensor bracket 44 is bifurcated and extends to the two bottom plate portions 44b. The two bosses 45 hang down from these two bottom plate portions 44b.

[0096] In other words, a notch 44c is formed in the lower part of the main body 44a of the sensor bracket 44, and the lower part of the main body 44a of the sensor bracket 44 is bifurcated so as to sandwich the notch 44c, with the notch 44c defining the distance between the two bottom plate portions 44b.

[0097] As shown in Figures 10 and 11, a portion of the upper end of the swing pin 41, which protrudes slightly above the anti-rotation arm 43, is positioned within the notch 44c of the sensor bracket 44 (the rear upper end of the swing pin 41 when it is in the default position D). In other words, the bifurcated main body portion 44a of the sensor bracket 44 is positioned to straddle the upper end of this swing pin 41.

[0098] As shown in Figure 10, a predetermined position Ps for the sensor bracket 44, which is suitable for the detection device 40s provided on the rotating structure 40, is set on the upper clamping portion 42a. In general terms, the position of the sensor bracket 44 that is suitable for the detection device 40s is a position in which the sensor 47 supported by the sensor bracket 44 can reliably detect the object to be detected 49 provided on the base portion 29 when the swing bracket 42 is in the default position D.

[0099] In this embodiment, when the sensor bracket 44 is positioned at a predetermined position Ps and attached to the upper clamping portion 42a, as shown in Figure 10, the distance Ls from the swing axis Y in the radial direction (horizontal direction) of the swing pin 41 to the main body portion 44a is smaller than the outer radius Lr of the swing pin 41. In other words, the shape of the sensor bracket 44 is such that it has a notch 44c as shown in Figure 12 (a bifurcated shape) to correspond to this.

[0100] Furthermore, if the main body portion 44a of the sensor bracket 44 can be positioned outside the swing pin 41 in the radial direction of the swing pin 41 (closer to the tip edge 42a2 of the upper clamping portion 42a than the swing pin 41) (or behind the rear end (A3) of the swing pin 41 if the swing bracket 42 is in the default position D), the main body portion 44a of the sensor bracket 44 may be bifurcated without providing a notch 44c, and the bottom plate portion 44b may be a single unit rather than a pair sandwiching the notch 44c, with two (or more) bosses 45 fixed to this single bottom plate portion 44b.

[0101] In other words, if the rotating structure 40 is configured such that the distance La of the main body 44a of the sensor bracket 44 positioned at a predetermined position Ps from the swing axis Y is greater than the outer radius Lb of the swing pin 41, the shape of the sensor bracket 44 may be one without a notch 44c as shown in Figure 12 (a non-bifurcated shape).

[0102] Thus, the shape of the sensor bracket 44 is not limited to that shown in Figure 12, and may be changed depending on conditions such as the positional relationship between the sensor bracket 44 and the swing pin 41 at the predetermined position Ps as described above.

[0103] Furthermore, the sensor bracket 44 is made of, for example, a metal plate, with a bifurcated main body portion 44a formed by punching or other processes of the metal plate, and a bottom plate portion 44b and a sensor mounting plate portion 44d (described later) formed by bending or other processes. However, the material of the sensor bracket 44 and the method of constructing each part of the sensor bracket 44 are not limited to these, and any material that can satisfy the various requirements for installing the detection device 40s on the rotating structure 40 in terms of rigidity, durability, ease of processing, economy, etc., is acceptable.

[0104] The method by which the predetermined position Ps of the sensor bracket 44 on the upper clamping portion 42a (i.e., the distance Ls from the swing axis Y of the main body portion 44a) is determined will be described in detail later.

[0105] As shown in Figures 7C and 10, in the upper clamping portion 42a of the swing bracket 42, an upward-facing open screw hole 42a3 is formed near the tip edge 42a2, corresponding to the boss hole 45a of the boss 45. The sensor bracket 44 is positioned so that the boss hole 45a of the boss 45 aligns with the screw hole 42a3.

[0106] Furthermore, if the sensor bracket 44 has multiple bosses 45 (two in this embodiment), the upper clamping portion 42a is provided with at least the same number of screw holes 42a3 as the bosses 45 (two in this embodiment). In this case, the sensor bracket 44 is provided with the boss holes 45a of each boss 45 each It is positioned to align with the screw hole 42a3.

[0107] Furthermore, as shown in Figures 7C, 8C, and 10, a smooth counterbore surface 42a4 is preferably formed on the upper surface of the upper clamping portion 42a, and the upper end of the screw hole 42a3 is opened at the counterbore surface 42a4. In this embodiment, two separate counterbore surfaces 42a4 are formed, and two screw holes 42a3 are opened separately at the two counterbore surfaces 42a4. Alternatively, two (or more) screw holes 42a3 may be opened at a single counterbore surface formed as a single unit.

[0108] As shown in Figures 10 and 12, the boss hole 45a is provided so as to penetrate the boss 45 vertically. Preferably, the boss 45 has a smooth lower end surface. As shown in Figures 7C, 8C, and 10, when the sensor bracket 44 is attached (tightened) to the upper clamping portion 42a of the swing bracket 42, the lower end of the boss hole 45a aligns with the upper end of the screw hole 42a3 with the smooth lower end surface of the boss 45 in contact with the smooth counterbore surface 42a4. Alternatively, a spacer (washer, spacer, etc.) may be interposed between the lower end surface of the boss 45 and the counterbore surface 42a4 instead of direct contact between them.

[0109] The upper end of the boss hole 45a opens upward on or above the upper surface of the bottom plate portion 44b. In this embodiment, as shown in Figure 12, the bottom plate portion 44b of the sensor bracket 44 is fixed in a flange-like manner to the upper and lower middle part of the boss 45, so the upper end of the boss 45 protrudes above the upper surface of the bottom plate portion 44b, and the upper end of the boss hole 45a opens on the upper end surface of the boss 45. However, the upper end of the boss 45 does not have to protrude above the upper surface of the bottom plate portion 44b of the sensor bracket 44 (i.e., it may protrude (hang) only below the bottom plate portion 44b). In this case, the upper end of the boss hole 45a (or the hole in the bottom plate portion 44b as an upper extension of the boss hole 45a) opens on the upper surface of the bottom plate portion 44b.

[0110] As shown in Figure 10, etc., the bolt (fastening member) 46 extends in the vertical direction, that is, in a direction parallel to the swing axis Y (swing axis Y direction), and is inserted into the boss hole 45a of the boss 45 from above the bottom plate portion 44b, passes through the boss hole 45a, and is screwed into the screw hole 42a3. The head of the bolt 46 screwed into the screw hole 42a3 is then fastened to the upper end surface of the boss 45 or the upper surface of the bottom plate portion 44b, preferably via a spacer 46a such as a washer, nut, or flange, as shown in Figures 7A, 7B, 8A to 11, or directly without a spacer, thereby fastening the sensor bracket 44 to the upper clamping portion 42a of the swing bracket 42 with the bolt 46.

[0111] In this way, the bolt 46 fastens the sensor bracket 44 to the upper clamping portion 42a, thereby restricting the relative movement of the sensor bracket 44 with respect to the swing bracket 42 both in the direction around the swing axis Y and in the direction of the swing axis Y. In other words, the bolt 46 prevents the sensor bracket 44 from rotating relative to the swing bracket 42 and also prevents (restricts) vertical rattle relative to the swing bracket 42.

[0112] As a result, the sensor 47, which is attached to the sensor bracket 44 as described later, is held in a predetermined relative position with respect to the upper clamping portion 42a, regardless of the vertical play of the swing pin 41 relative to the swing bracket 42 as described later.

[0113] Furthermore, preferably, as in this embodiment, multiple (two in this embodiment) bolts 46 are fastened to the upper clamping portion 42a of the sensor bracket 44, corresponding to multiple (two in this embodiment) bosses 45 provided on the sensor bracket 44, thereby more reliably restricting the relative movement of the sensor bracket 44 with respect to the swing bracket 42 in the direction around the swing axis Y and in the direction of the swing axis Y.

[0114] In other words, preferably, the rotating structure 40 is provided with a plurality of fastening mechanisms 50, each having a boss (cylindrical portion) 45 and a bolt (fastening member) 46 (one pair in this embodiment). Alternatively, the fastening mechanism 50 is provided with a plurality of bosses (cylindrical portions) 45 (one pair in this embodiment) and a plurality of bolts (fastening members) 46 (one pair in this embodiment). By fastening the sensor bracket 44 to the swing bracket 42 with such a plurality of fastening mechanisms 50, or with a fastening mechanism 50 equipped with a plurality of bosses (cylindrical portions) 45 and a plurality of bolts (fastening members) 46, the relative movement of the sensor bracket 44 with respect to the swing bracket 42 can be restricted more reliably.

[0115] In this embodiment, the fastening member that fastens the sensor bracket 44 to the swing bracket 42 (upper clamping portion 42a) is a bolt 46, but the fastening member is not limited to a bolt. For example, the fastening member may be a screw. Alternatively, the fastening member may be a screw rod and a nut, with the screw rod provided on the upper clamping portion 42a so as to extend toward the information, and the nut may be screwed onto the screw rod after it is inserted into the boss 45, and the boss 45 may be tightened to the upper clamping portion 42a with the nut.

[0116] As shown in Figure 10, the boss 45 is inserted through the hole 43b of the anti-rotation arm 43 as described above, and is fastened to the upper clamping portion 42a with a bolt 46. The outer circumferential surface of the boss 45 slides against the circumferential surface of the hole 43b, and there is no room for the boss 45 to move relative to the hole 43b in the horizontal direction (around the swing axis Y), but the anti-rotation arm 43 can slide along the boss 45 in the vertical direction (swing axis Y direction) within a predetermined range (play).

[0117] As shown in Figure 10, the anti-rotation arm 43 is positioned between the bottom plate portion 44b of the sensor bracket 44 and the upper surface of the upper clamping portion 42a, with a certain vertical distance L1 corresponding to the vertical length of the boss 45 separating the bottom plate portion 44b and the upper surface of the upper clamping portion 42a. The anti-rotation arm 43 has a vertical thickness L2. Therefore, sliding of the anti-rotation arm 43 along the boss 45 is permitted within a predetermined range (play) corresponding to the difference L3 between the distance L1 and the thickness L2.

[0118] This allows for vertical play of the swing pin 41 relative to the swing bracket 42 within that range. In other words, while vertical play of the swing pin 41 relative to the swing bracket 42 is permitted, the sensor bracket 44 is fixed (tightened) in a state where vertical play is suppressed relative to the swing bracket 42 (upper clamping portion 42a).

[0119] Thus, the upper end of the main body portion 44a of the sensor bracket 44, which is fixed (tightened) to the upper clamping portion 42a, is provided with a horizontally extending sensor mounting plate portion 44d, a vertical plate-shaped relay mounting plate portion 44e, and a vertical plate-shaped cover mounting plate portion 44f, as shown in Figure 12, etc.

[0120] As shown in Figures 7A, 7B, 8A to 11, the sensor element holder 47a (detector), which is the main body of the sensor 47, is mounted on the sensor mounting plate 44d with its head (sensor head) facing downwards. The relay 47c, which is part of the sensor 47 and is connected to the sensor element holder 47a via electrical wiring (harness, cable, etc.) 47b, is mounted on the relay mounting plate 44e. A cover 48 that covers the sensor 47 (sensor element holder 47a, electrical wiring (harness, cable, etc.) 47b, and relay 47c) is fastened to the cover mounting plate 44f with bolts or screws.

[0121] As shown in Figures 8A, 8B, 9A to 11, the sensor 47 has a sensing area Rs limited to directly below the lower end of the sensor element holder 47a (detector), which is the sensor head. Furthermore, as shown in Figures 7A, 7B, 9A to 11, it is positioned at a predetermined position Ps above The sensor mounting plate portion 44d of the sensor bracket 44, which is fastened to the clamping portion 42a, extends horizontally beyond the tip edge 42a2 to the outside of the upper clamping portion 42a (rearward when the swing bracket 42 is in the default position D). The sensing area Rs directly below the sensor element holder 47a attached to this sensor mounting plate portion 44d is positioned above the base portion 29 that extends rearward (A3) from the tip edge 42a2 of the upper clamping portion 42a when the swing bracket 42 is in the default position D.

[0122] On the other hand, on the base portion 29 of the machine body 20, as shown in Figures 7A to 11, the object to be detected 49 is fixed to the base portion 29 so as to protrude upward from the upper surface of the base portion 29. In this embodiment, the stay portion 49b at the bottom of the object to be detected 49 that is in contact with the upper surface of the base portion 29 is fastened to the base portion 29 with fastening members such as bolts. However, it is sufficient that the object to be detected 49 is fixed to the base portion 29 in such a way that it cannot move relative to the base portion 29 in any direction. For example, the object to be detected 49 may be fixed to the upper surface of the base portion 29 by welding or the like, or it may be molded integrally with the base portion 29 (main frame 21) from the beginning.

[0123] The detection device 40s is configured to detect whether the swing bracket 42 is in the default position D based on the detection of the object to be detected 49 by the sensor 47. In addition, the device is configured so that an operator sitting in the driver's seat 26 can determine whether the swing bracket 42 is in the default position D by looking at the state of the detection device 40s located in front of them.

[0124] In other words, as shown in Figures 5 to 7A, 8A, 9A, etc., the sensor cover 48 is provided with a marker 48a. When the swing bracket 42 is in the default position D, as seen by an operator sitting in the driver's seat 26, this marker 48a appears to be aligned vertically in a line with the detected object 49 provided on the base portion 29, as shown in Figure 8A.

[0125] Furthermore, as can be seen in Figure 8A, the left-right direction B1 of the base portion 29 (i.e., the machine body 20) substantially coincides with the rotation (oscillation) direction of the upper clamping portion 42a of the swing bracket 42 in and around the default position D. Therefore, when the swing bracket 42 deviates from the default position D, the marker 48a shifts to the left (B2) or right (B3) from the position corresponding to the object to be detected 49, as seen from the perspective of the operator sitting in the operator's seat 26. Consequently, when the operator sitting in the operator's seat 26 detects a left-right shift in the marker 48a relative to the object to be detected 49, they can determine that the swing bracket 42 (working device 30) has deviated from the default position D.

[0126] In this way, the operator sitting in the driver's seat 26 can determine whether the swing bracket 42 is in the default position D by looking at the detection device 40s in front with their own eyes and confirming the positional relationship between the marker 48a on the sensor cover 48 and the object to be detected 49. Furthermore, when the operator sitting in the driver's seat 26 extends and retracts the swing cylinder 39 by pressing the swing pedal 63a to rotate (oscillate) the work device 30, they can determine whether the swing bracket 42 has reached the default position D by visually confirming the positional relationship between the marker 48a on the sensor cover 48 and the object to be detected 49.

[0127] In this embodiment, the marker 48a is a projection formed on the upper end of the sensor cover 48, but the configuration is not limited to this. For example, the marker 48a may be painted or written on the sensor cover 48 with paint or the like, and its position is not limited to the upper end of the sensor cover 48, but may be provided at a lower position or the like.

[0128] Now, various configurations are possible for the sensor (detector) 47 and the object to be detected 49. For example, the sensor 47 may be an optical sensor, and the object to be detected 49 may be detectable by the optical sensor. This could involve defining the material or physical characteristics.

[0129] However, in the detection device 40s according to this embodiment, the sensor 47 is a magnetic proximity sensor (having a Hall element, reed switch, or magnetoresistive (MR) sensor element, etc.), and the object to be detected 49 is made of a magnetic material such as iron, nickel, or cobalt that can have a magnetic field detectable by the magnetic proximity sensor. The following description of the rotating structure 40 (including the detection device 40s) is based on the premise that the sensor 47 is a magnetic proximity sensor and the object to be detected 49 is a magnetic material.

[0130] The object to be detected 49 has a sensing portion 49a at its upper end that is closest to the sensor head at the lower end of the sensor element holder (detector) 47a. As the swing bracket 42 rotates around the swing axis Y, the sensor 47 senses the magnetic field at the object to be detected 49 most strongly when the sensing portion 49a enters the sensing area Rs and comes close to the lower end (sensor head) of the sensor element holder (detector) 47a.

[0131] Therefore, in the swing control system 100 shown in Figure 13, the default determination signal Sd input from the detection device 40s to the control device 101 is set as a signal indicating the strength of the magnetic field sensed by the sensor 47, and the strength of the magnetic field sensed by the sensor 47 when the sensed part 49a enters the sensing area Rs is set as a threshold. By comparing the strength of the magnetic field indicated by the default determination signal Sd with the threshold, the control device 101 can determine whether or not the swing bracket 42 is in the default position D.

[0132] As described above, the sensor bracket 44 supporting the sensor 47 is fastened to the upper clamping portion 42a of the swing bracket 42 so as not to move up and down. This prevents the sensor element holder 47a from moving up and down relative to the swing bracket 42, and as shown in Figures 8B and 8C, the vertical distance Rd from the part to be detected 49a that has entered the sensing area Rs to the sensor head at the lower end of the sensor element holder 47a is kept constant. Therefore, each time the part to be detected 49a enters the sensing area Rs, the sensor 47 always detects a constant magnetic field strength, and the detection accuracy of the detection device 40s, which is configured to detect whether the swing bracket 42 is in the default position D, is stabilized.

[0133] Furthermore, in order to reliably keep the swing bracket 42 in the default position D when the crane mode is set, it is necessary to narrow as much as possible the range of rotation (oscillation) angle of the swing bracket 42 around the swing axis Y in which the sensor 47 detects the presence of the sensed part 49a within the sensing range Rs.

[0134] Therefore, in the detection device 40s, a proximity sensor with a narrow sensing range Rs is used as the sensor 47, and as the object to be detected 49 made of a magnetic material, as shown in Figures 5 to 8C, a member with a narrow width in the left-right direction B1 (approximately coincides with the rotation (oscillation) direction of the upper clamping portion 42a of the swing bracket 42 at the default position D and its vicinity) of the base portion 29 (machine body 20) is used.

[0135] In other words, as shown in Figures 8A to 8C, the detected object 49 has a uniform width W1 in the left-right direction B1 from its upper end as the sensed portion 49a to its lower end as the base of the stay portion 49b. This width W1 is suitably set so that the sensor 47 does not detect the presence of the sensed portion 49a within the sensing area Rs even when the swing bracket 42 has deviated from its default position D, by considering the width W2 in the left-right direction B1 of the sensing area Rs of the sensor 47 on the upper clamping portion 42a of the swing bracket 42 at and near the default position D.

[0136] Although the stay portion 49b of the object to be detected 49 extends far in the left-right direction B1, the stay portion 49b is fixed to the base portion 29 at a position that is radially outside the sensing range Rs of the swing pin 41, that is, as shown in Figures 9A and 9B, at a position (A3) behind the sensing range Rs of the sensor 47 on the upper clamping portion 42a when it is in the default position D, so that the sensor 47 does not sense the magnetic field of the stay portion 49b regardless of the position of rotation (oscillation) of the swing bracket 42 around the swing axis Y.

[0137] Thus, as shown in Figures 9A and 9B, the detected object 49 has an upper and lower extension portion 49c that extends upward from the stay portion 49b to the upper and lower middle portion, connecting the stay portion 49b, which is located outside the sensing area Rs, and the detected object 49, which is located in a position that allows it to enter the sensing area Rs. Furthermore, it has an inclined extension portion 49d that is bent at the upper and lower middle portion (the upper end of the upper and lower extension portion 49c) and extends in a forward-upward inclined manner from the bent portion to the detected object 49a at the upper end. These upper and lower extension portions 49c and the inclined extension portion 49d have the aforementioned uniform width W1.

[0138] In the detected object 49 with this configuration, the sensor 47 may detect the magnetic field of the inclined extension portion 49d that extends near the sensing area Rs. However, the inclined extension portion 49d extends along the radial direction of the swing pin 41 and has a limited, uniform width W1, taking into consideration the width W2 of the sensing area Rs, as described above. Therefore, the sensor 47 only detects the magnetic field of the inclined extension portion 49d outside the sensing area Rs when it simultaneously detects the magnetic field of the detected object 49a, and thus does not affect the accuracy of determining whether the swing bracket 42 is in the default position D.

[0139] On the other hand, regarding the position setting of the sensing area Rs of the sensor 47, the distance of the sensing area Rs of the sensor 47 from the swing axis Y depends on the distance Ls of the sensor bracket 44 (main body 44a) from the swing axis Y. This distance Ls is determined to satisfy the following requirements.

[0140] First, in order to make the swing bracket 42 more compact, it is desirable that the horizontal distance (length) from the swing axis Y of the upper clamping portion 42a to the tip edge 42a2 be as short as possible. To meet this requirement, it is desirable that the distance Ls of the sensor bracket 44 (its main body portion 44a) from the swing axis Y be as short as possible.

[0141] On the other hand, for example, when the boom 31 and arm 32 are extended in a nearly horizontal direction at a low position, even with the same amount of horizontal movement due to the rotation (oscillation) of the swing bracket 42 around the swing axis Y, the amount of movement of the part of the work device 30 that is located furthest from the swing axis Y in the horizontal direction (radial direction of the swing pin 41), such as the tip of the bucket 33 (hereinafter referred to as the "farthest part"), becomes larger than the amount of movement of the tip edge 42a2 of the upper clamping part 42a.

[0142] Consequently, even if the amount of horizontal movement of the tip edge 42a2 due to the rotation (oscillation) of the swing bracket 42 around the swing axis Y is small, and the swing bracket 42 is still considered to be within the default position D, the amount of movement of the furthest part of the work device 30 may exceed the range that can be considered to be within the default position D.

[0143] Taking into consideration the amount of movement of the furthest part of the work device 30, which tends to be large, when setting the region in which the sensor 47 senses a magnetic field of such strength that the swing bracket 42 is determined to be in the default position D, the relative movement of the sensor 47 with respect to the detected object 49 due to the rotation (oscillation) of the swing bracket 42 around the swing axis Y and the furthest part of the work device 30 To minimize the difference with respect to the amount of movement, it is desirable that the distance Ls of the sensor bracket 44 (main body 44a) from the swing axis Y be as long as possible.

[0144] Therefore, it is preferable that the distance Ls of the sensor bracket 44 (or its main body 44a) from the swing axis Y be set to a value suitable for satisfying the aforementioned conflicting requirements.

[0145] The specific configuration of the rotating structure 40, including the detection device 40s, has been described above. Next, the effects of the rotating structure 40 and some configurations of the work machine 1 equipped with the rotating structure 40 will be explained.

[0146] (Item 1) A rotating structure 40 comprising a base portion 29, a detected object 49 fixed to the base portion 29, a pivot (swing pin) 41 rotatably supported on the base portion 29 around an axis (swing axis) Y, a swing bracket 42 attached to the base portion 29 via the pivot 41 and rotatably relative to the base portion 29 by rotating together with the pivot 41, a sensor 47 for detecting the detected object 49, and a sensor bracket 44 that supports the sensor 47 and is fastened to the swing bracket 42.

[0147] As a result, the sensor bracket 44, which is fastened to the swing bracket 42, does not swing vertically relative to the swing bracket 42, and therefore the sensor 47, which is supported by the sensor bracket 44, does not swing vertically relative to the swing bracket 42. This stabilizes the positional relationship between the sensor 47, which is attached to the swing bracket 42 via the sensor bracket 44, and the object to be detected 49, which is fixed to the base portion 29, and also stabilizes the ability (sensitivity) of the sensor 47 to detect the object to be detected 49.

[0148] (Item 2) The rotational structure 40 according to Item 1, comprising a rotation-preventing member 43 fixed to the pivot 41, a sensor bracket 44 fastened to the swing bracket 42, and a fastening mechanism 50 that restricts the rotation of the rotation-preventing member 43 relative to the swing bracket 42 about the axis Y of the pivot 41.

[0149] As a result, the fastening mechanism 50 allows the sensor bracket 44 supporting the sensor 47 to be easily and securely fastened to the swing bracket 42 while restricting both relative rotation of the pivot 41 around the axis Y and relative movement in the axis Y direction, thereby easily stabilizing the positional relationship between the sensor 47 and the object to be detected 49 (stabilizing the sensitivity of the sensor 47).

[0150] (Item 3) The rotating structure 40 according to Item 2, wherein the fastening mechanism 50 comprises a cylindrical portion 45 fixed to the sensor bracket 44, and a fastening member 46 inserted through the cylindrical portion 45 and attached to the swing bracket 42, thereby fastening the sensor bracket 44 to the swing bracket 42.

[0151] As a result, the sensor bracket 44, which supports the sensor 47, is easily and securely fastened to the swing bracket 42 by a fastening member 46 inserted through a cylindrical portion 45 fixed to the sensor bracket 44, while restricting both relative rotation of the pivot 41 around the axis Y and relative movement in the axis Y direction. This makes it easy to stabilize the positional relationship between the sensor 47 and the object to be detected 49 (stabilizing the sensitivity of the sensor 47).

[0152] (Item 4) The rotational structure 40 according to Item 3, wherein the cylindrical portion 45 is inserted through the anti-rotation member 43 and attached to the swing bracket 42 by the fastening member 46, thereby restricting the relative rotation of the anti-rotation member 43 with respect to the swing bracket 42 of the pivot 41 around the axis Y.

[0153] As a result, the anti-rotation member 43 fixed to the pivot 41 is inserted through the cylindrical portion 45 which is fastened to the swing bracket 42 together with the sensor bracket 44, thereby ensuring that the pivot 41 rotates (oscillates) integrally with the swing bracket 42 relative to the base portion 29.

[0154] (Item 5) The cylindrical portion 45 is provided integrally with the sensor bracket 44 by molding, the rotating structure 40 as described in Item 3 or 4.

[0155] This eliminates the need for special processes or effort to fix the cylindrical body 45 to the sensor bracket 44, thereby achieving the economic efficiency required for the rotating structure 40.

[0156] (Item 6) A work machine 1 having a rotating structure 40 according to any one of Items 1 to 5, comprising: a machine body 20 having the base portion 29; a work device 30 supported by the swing bracket 42; and an actuator 39 interposed between the machine body 20 and the swing bracket 42 and capable of driving the swing bracket 42 to rotate relative to the base portion 29.

[0157] As a result, the work machine 1 is equipped with a rotating structure 40 having a sensor 47 capable of detecting the object to be detected 49 with stable sensitivity, thereby improving the accuracy of relative rotational position control of the work device 30 with respect to the machine body 20 via the actuator 39 and the rotating structure 40. For example, when the crane mode is set, the swing bracket 42 and the work device 30 are reliably held in the default position D.

[0158] While embodiments of the present invention have been described above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope of equivalence to the claims are intended to be included. [Explanation of Symbols]

[0159] 1. Working equipment (swivel-type excavator) 20 aircraft 29 Base 30 Working equipment 39. Swing cylinder (actuator) 40 Rotating Structures 41 Swing pin (pivot) 42 Swing Bracket 43. Anti-rotation arm (anti-rotation member) 44 Sensor bracket 45 Boss (Cylindrical part) 46 Bolts (fastening components) 47 Sensors 49. Detected object Y Swing axis (axis)

Claims

1. Base and The object to be detected is fixed to the base portion, The base portion is supported by a pivot that is rotatable around its axis, A swing bracket is attached to the base portion via the pivot and rotates together with the pivot, thereby allowing it to rotate relative to the base portion. A sensor for detecting the object to be detected, A sensor bracket that supports the sensor and is fastened to the swing bracket, A rotating structure equipped with the following features.

2. A rotation-preventing member fixed to the pivot, The rotating structure according to claim 1, wherein the sensor bracket is fastened to the swing bracket, and the structure further comprises a fastening mechanism that restricts the rotation of the anti-rotation member around the axis of the pivot relative to the swing bracket.

3. The fastening mechanism is A cylindrical portion fixed to the aforementioned sensor bracket, A fastening member that is inserted through the cylindrical portion and attached to the swing bracket, thereby fastening the sensor bracket to the swing bracket, The rotating structure according to claim 2, comprising:

4. The rotational structure according to claim 3, wherein the cylindrical portion is inserted through the anti-rotation member and attached to the swing bracket by the fastening member, thereby restricting the relative rotation of the anti-rotation member around the axis of the pivot with respect to the swing bracket.

5. The rotating structure according to claim 3, wherein the cylindrical portion is integrally molded with the sensor bracket.

6. The machine having the base portion, A work device supported by the aforementioned swing bracket, An actuator is interposed between the aforementioned body and the swing bracket, causing the swing bracket to rotate relative to the base portion, A work machine having a rotating structure according to any one of claims 1 to 5.

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