US-12624519-B2 - Shovel

US12624519B2US 12624519 B2US12624519 B2US 12624519B2US-12624519-B2

Abstract

A shovel includes a lower traveling body, an upper turning body turnably mounted on the lower traveling body, an attachment including a boom attached to the upper turning body, an arm attached to an end of the boom, and an end attachment attached to an end of the arm, wherein a motion of the arm or the end attachment is corrected according to a stability of a body of the shovel.

Inventors

Junichi Okada
Keiji Honda

Assignees

SUMITOMO HEAVY INDUSTRIES, LTD.

Dates

Publication Date: 20260512
Application Date: 20210325
Priority Date: 20180927

Claims (20)

1 . A shovel comprising: a lower traveling body: an upper turning body turnably mounted on the lower traveling body; an attachment including a boom attached to the upper turning body, an arm attached to an end of the boom, and an end attachment attached to an end of the arm; an arm cylinder configured to drive the arm; a hydraulic pump configured to supply hydraulic oil to the arm cylinder; a relief valve configured to release a pressure of the hydraulic oil in a rod-side oil chamber of the arm cylinder; and a hardware processor configured to correct a motion of the arm or the end attachment according to a stability of a body of the shovel during aerial motion of the attachment, wherein the hardware processor is configured to, in a case of correcting the motion of the arm, correct the motion of the arm to move the arm in a closing direction, in response to identifying a predetermined motion of the shovel that causes the body of the shovel to be in an unstable state, the hardware processor is configured to, in response to identifying the predetermined motion of the shovel, cause the relief valve to release the pressure in the rod-side oil chamber of the arm cylinder by discharging the hydraulic oil in the rod-side oil chamber of the arm cylinder to a hydraulic oil tank, to allow the arm to be moved in the closing direction by a weight of the arm during the aerial motion of the attachment, a stable range of the attachment where a degree of static stability of the attachment is more than or equal to a predetermined reference is defined around the shovel, the stable range is an area surrounding the lower traveling body in a plane in which the lower traveling body is positioned, and an outer edge of the stable range is spaced apart from the lower traveling body, and the hardware processor is configured to determine whether a position of the end attachment relative to the lower traveling body is beyond the outer edge of the stable range, and to determine that the body of the shovel is in a static unstable state in response to determining that the position of the end attachment relative to the lower traveling body is beyond the outer edge of the stable range.
2 . The shovel according to claim 1 , wherein the hardware processor is configured to move the arm and the end attachment according to an operation content or a motion instruction of an automatic drive function when the body is in a stable state, and correct the motion of the arm or the end attachment in such a manner as to recover the stability compared with the motion according to the operation content or the motion instruction when the body is in an unstable state including the static unstable state.
3 . The shovel according to claim 1 , wherein the hardware processor is configured to move the arm in the closing direction so as to reduce a possibility of a dynamic moment exerted on the body including the lower traveling body and the upper turning body, in response to identifying the predetermined motion of the shovel.
4 . The shovel according to claim 3 , wherein the predetermined motion includes: a motion in which the attachment unloads an object loaded in a bucket serving as the end attachment; a motion in which the lower traveling body rapidly decelerates while the lower traveling body is traveling with the attachment being oriented in a traveling direction: or a motion of increasing an amount of a forward tilt of the body while the lower traveling body is traveling with the attachment being oriented in the traveling direction, or includes two or more thereof.
5 . The shovel according to claim 1 , wherein the hardware processor is configured to move the arm in the closing direction so as to reduce a change in a static moment exerted on the body including the lower traveling body and the upper turning body.
6 . The shovel according to claim 5 , wherein the predetermined motion includes: a lowering motion for lowering the boom while a distance between the end attachment and the body is more than a predetermined threshold value; a motion in which the attachment loads and raises a target object on a bucket serving as the end attachment: a motion of turning the upper turning body so that a direction of the attachment moves away from a traveling direction of the lower traveling body: or a motion in which an amount of forward tilt of the body increases while the lower traveling body is traveling with the attachment being oriented in the traveling direction, or includes two or more thereof.
7 . The shovel according to claim 1 , wherein the hardware processor is configured to slow an opening motion of the end attachment in response to determining that there is a possibility or an occurrence of a lift of a rear part of the lower traveling body.
8 . The shovel according to claim 7 , wherein the hardware processor is configured to slow the opening motion of the end attachment in response to determining that a weight of the end attachment is larger than a predetermined value, or in response to determining that a distance between the position of the end attachment and the lower traveling body is more than a predetermined threshold value.
9 . The shovel according to claim 7 , wherein the end attachment is a bucket, and the hardware processor is configured to slow an opening motion of the bucket when the attachment makes a movement of unloading an object loaded in the bucket.
10 . The shovel according to claim 9 , wherein the hardware processor is configured to slow the opening motion of the bucket in response to determining that a distance between a position of the bucket and the lower traveling body is more than a predetermined threshold value when the attachment makes the movement of unloading.
11 . The shovel according to claim 9 , wherein the hardware processor is configured to slow the opening motion of the bucket in response to determining that there is the possibility or the occurrence of the lift of the rear part of the lower traveling body when the attachment makes the movement of unloading.
12 . The shovel according to claim 7 , further comprising: an end attachment cylinder configured to drive the end attachment, wherein the hydraulic pump is configured to supply the hydraulic oil to the end attachment cylinder, and the hardware processor is configured to slow the opening motion of the end attachment by: limiting a discharge flowrate of the hydraulic pump supplying the hydraulic oil to the end attachment cylinder; causing a control valve configured to control a flowrate of the hydraulic oil supplied from the hydraulic pump to the end attachment cylinder to limit the flowrate of the hydraulic oil to the end attachment cylinder; or causing a throttle valve provided in a hydraulic path between the control valve and the end attachment cylinder to reduce a flowrate of the hydraulic oil discharged from the end attachment cylinder.
13 . The shovel according to claim 12 , wherein the hardware processor is configured to slow the opening motion of the end attachment by limiting a movement velocity or a movement acceleration of the end attachment cylinder to a predetermined upper limit value or less or limiting both of the movement velocity or the movement acceleration to the predetermined upper limit value or less.
14 . The shovel according to claim 13 , further comprising: a predetermined sensor configured to detect a state of the attachment, wherein the hardware processor is configured to calculate the predetermined upper limit value based on detection information of the predetermined sensor.
15 . The shovel according to claim 14 , wherein the hardware processor is configured to calculate an overturning moment in a direction to lift up the rear part of the lower traveling body and a restraining moment in a direction to restrain lifting up of the rear part of the lower traveling body based on the detection information of the predetermined sensor, and to calculate the predetermined upper limit value so that the overturning moment falls below the restraining moment.
16 . The shovel according to claim 1 , wherein the end attachment is a bucket, the hardware processor is configured to correct the motion of the arm to move the arm in the closing direction while the bucket is opening during the aerial motion of the attachment, and the hardware processor is configured to slow an opening of the bucket while moving the arm in the closing direction.
17 . The shovel according to claim 16 , further comprising: a bucket cylinder configured to drive the bucket, wherein the hardware processor is configured to slow the opening of the bucket by limiting a movement acceleration of the bucket cylinder to an upper limit movement acceleration.
18 . The shovel according to claim 17 , wherein the hardware processor is configured to slow the opening of the bucket by further limiting a movement velocity of the bucket cylinder to an upper limit movement velocity after limiting the movement acceleration of the bucket cylinder to the upper limit movement acceleration.
19 . The shovel according to claim 1 , wherein the hydraulic pump is a variable displacement hydraulic pump and is configured to supply the hydraulic oil to the rod-side oil chamber of the arm cylinder, and the relief valve is configured to discharge the hydraulic oil in the rod-side oil chamber of the arm cylinder supplied by the hydraulic pump.
20 . The shovel according to claim 1 , wherein the outer edge of the stable range is defined by a first side, a second side, a third side, and a fourth side, the first side curving toward a front side of the lower traveling body, the second side curving toward a rear side of the lower traveling body, the third side curving toward a left side of the lower traveling body, the fourth side curving toward a right side of the lower traveling body.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation application filed under 35 U.S.C. 111(a) claiming benefit under 35 U.S.C. 120 and 365(c) of PCT International Application No. PCT/JP2019/037932, filed on Sep. 26, 2019, and designating the U.S., which claims priority to Japanese Patent Application No. 2018-181988 filed on Sep. 27, 2018, and Japanese Patent Application No. 2018-188453 filed on Oct. 3, 2018. The entire contents of the foregoing applications are incorporated herein by reference. BACKGROUND Technical Field The present disclosure relates to a shovel. Description of Related Art For example, during an excavation operation and the like, a technique for alleviating a predetermined unstable phenomenon such as lifting up and the like of a rear part that occurs with the body of the shovel is known. SUMMARY According to an aspect of the present disclosure, provided is a shovel including a lower traveling body, an upper turning body turnably mounted on the lower traveling body, an attachment including a boom attached to the upper turning body, an arm attached to an end of the boom, and an end attachment attached to an end of the arm, wherein a motion of the arm or the end attachment is corrected according to a stability of a body of the shovel. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view illustrating an example of a shovel; FIG. 2 is a block diagram illustrating a first example of a configuration of a shovel; FIG. 3 is a block diagram illustrating a second example of a configuration of a shovel; FIG. 4 is a block diagram illustrating a third example of a configuration of a shovel; FIG. 5 is a diagram illustrating an example of a hydraulic circuit including a hydraulic oil holding circuit and a relief valve in detail; FIG. 6A is a drawing illustrating a specific example of a rear part lifting up phenomenon of the shovel; FIG. 6B is a drawing illustrating a specific example of a rear part lifting up phenomenon of the shovel; FIG. 7 is a drawing for explaining static overturning moment exerted on the body of the shovel; FIG. 8 is a plan view illustrating a specific example of a stable range of the shovel in view of the direction of the upper turning body with respect to the lower traveling body; FIG. 9A is a plan view illustrating a specific example of a stable range of the attachment in view of the inclination of the work surface; FIG. 9B is a plan view illustrating a specific example of a stable range of the attachment in view of the inclination of the work surface; FIG. 10 is a side view illustrating another example of a shovel; FIG. 11 is a block diagram illustrating a fourth example of a configuration of a shovel; FIG. 12 is a graph for explaining an example of a control scheme of a stabilization control for reducing a rear part lifting up phenomenon; FIG. 13 is a block diagram illustrating a fifth example of a configuration of a shovel; FIG. 14 is a block diagram illustrating a sixth example of a configuration of a shovel; and FIG. 15 is a diagram illustrating an example of a configuration of a shovel management system. EMBODIMENT OF THE INVENTION For example, during an excavation operation and the like, a technique for alleviating a predetermined unstable phenomenon such as lifting up and the like of a rear part that occurs with the body of the shovel is known. However, when an attachment is in the air (hereinafter referred to as “during aerial motion of attachment”), an unstable phenomenon such as lifting up and the like of the rear part may occur in the body of the shovel according to the motion of the shovel. Therefore, in view of the above circumstances, it is desired to provide a shovel capable of alleviating an unstable phenomenon that could occur with the body of the shovel during aerial motion of the attachment. Hereinafter, an embodiment for carrying out the invention is described with reference to the drawings. [Overview of Shovel] First, an overview of a shovel 100 according to the present embodiment will be explained with reference to FIG. 1. FIG. 1 is a side view of the shovel 100 according to the present embodiment. The shovel 100 according to the present embodiment includes a lower traveling body 1, an upper turning body 3 mounted on the lower traveling body 1 turnably with a turn mechanism 2, a boom 4 (an example of a “work attachment”), an arm 5, a bucket 6, and a cab 10 in which an operator rides. Hereinafter, a front side of the shovel 100 corresponds to a direction in which an attachment extends with reference to the upper turning body 3 (hereinafter simply referred to as a “direction in which the attachment extends”) when the shovel 100 is seen in a plan view as seen from immediately above along the turning axis of the upper turning body 3 (hereinafter simply referred to as a “plan view”). The left-hand side and the right-hand side of the shovel 100 correspond to the left-hand side and the right-hand side, respectively, of the operator in the c