Working machine

Abstract

To provide a working machine capable of continuing the work while enabling detection of a load.SOLUTION: A working machine A includes a boom device 41 having a boom enabling at least one time turning, and a work section 51 disposed at the tip of the boom device 41. The work section 51 has a connection body for connecting the boom device 41 and the work section 51. The boom device 41 includes: a first fulcrum shaft connecting a second connection body 414, and disposed so as to turn the second connection body 414 in a circumferential direction relative to the boom device 41; a detection section w disposed adjacently to the second connection body 414, and capable of detecting turning in the circumferential direction of the first fulcrum shaft of the work section 51, and issuing a detection signal when detecting turning; and a control section t for controlling the movement of the boom device 41 based on the detection signal.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a work machine. [Background technology]

[0002] When mowing work is performed at a location away from a certain point, the work can be performed efficiently if only the working section of a working machine using a boom device or the like that performs the mowing work is positioned far away. One example is the working machine described in Patent Document 1, which is often used when mowing grass on road shoulders and slopes, etc. The invention described in Patent Document 1 provides a shock absorbing mechanism to a support arm that holds the working device body, and the support arm is provided with a bendable fulcrum. When a load of a predetermined magnitude or more is applied to the fulcrum, the arm bends midway and the grass cutting device body moves backward, thereby dissipating the load in the event of a collision. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-292439 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the support arm is bent and the working part, the grass cutting device body, moves backward, the working part is not in the correct position and work cannot be continued. In order to continue work, the grass cutting device body that has moved backward must be returned to the reset position, which poses the problem of temporarily interrupting work. In addition, since the operator cannot know whether the load has reached the allowable limit, there is also the problem that the operator cannot take preemptive measures such as avoiding obstacles or stopping the progress of the machine. [Means for solving the problem]

[0005] The present invention relates to A boom device having at least one rotatable boom; a working unit provided at a tip of the boom device, the working unit includes a connector that connects the boom device and the working unit, The boom device includes a fulcrum shaft that connects the connecting body and is provided so that the connecting body can rotate in a circumferential direction relative to the boom device; a detection unit provided adjacent to the connecting body, capable of detecting rotation of the fulcrum shaft of the working unit in the circumferential direction and capable of issuing a detection signal when the rotation is detected; a control unit that controls an operation of the boom device based on the detection signal; A working machine comprising: relates to.

[0006] The present invention further comprises: When the control unit receives the detection signal, it transmits an operation signal for rotating the boom device. A working machine characterized by: relates to.

[0007] The present invention further comprises: When the control unit does not receive the detection signal after transmitting the operation signal, the control unit stops transmitting the operation signal to stop the rotation operation of the boom device. A working machine characterized by: relates to.

[0008] The present invention further comprises: When the control unit receives the detection signal, the control unit performs display control to display on a display device that a load is being applied. A working machine characterized by: relates to.

[0009] The present invention further comprises: When the control unit receives the detection signal, the control unit performs notification control to notify an operator by voice or the like. A working machine characterized by: relates to.

[0010] The present invention further comprises: The boom device includes a cylinder for rotating the boom, The cylinder operates via a directional control valve that controls the actuation of the cylinder. A working machine characterized by: relates to. Effect of the Invention

[0011] An object of the present invention is to provide a work machine that is capable of continuing work while being able to detect a load. [Brief description of the drawings]

[0012] [Figure 1] It is a rear view of the working machine according to the embodiment of the present invention, showing a state in which the boom device is deployed.It is a view seen from the rear in the traveling direction. [Diagram 2] 1 is a plan view of a working machine according to an embodiment of the present invention when unfolded, showing a state in which the boom device is in an unfolded state and the working section has been moved forward. [Diagram 3] Fig. 2 is a front view of the working machine according to the embodiment of the present invention, showing the periphery of the main part when the boom device is deployed, as viewed from the front in the traveling direction to the rear side. [Figure 4] Fig. 2 is a partially enlarged cross-sectional view of a working machine according to an embodiment of the present invention, showing a side cross-section of a main part, with the left side of the drawing being the front in the direction of travel, and showing a state in which the second boom has moved forward and the second connecting body has not yet rotated. [Diagram 5] Fig. 2 is a cross-sectional view of a working machine according to an embodiment of the present invention, showing a side cross-section of a main part, with the left side of the drawing being the front in the direction of travel, and shows a state after the second boom has moved forward and the second connecting body has rotated. [Figure 6] Fig. 1 is a partially enlarged cross-sectional view of a working machine according to an embodiment of the present invention. A side cross-sectional view of the periphery of a first connecting body is shown. The left is the front in the direction of travel. The second boom is shown in a state in which it has moved forward. There is no change before and after the second connecting body rotates. [Figure 7]1 is a side view of a working machine according to an embodiment of the present invention, showing a regulating portion as viewed from the right side, with the right side in the drawing being the front in the direction of travel, and shows a state before a second connecting body is rotated. [Figure 8] 1 is a side view of a working machine according to an embodiment of the present invention, showing a regulating portion as viewed from the right side, with the right side in the drawing being the front in the direction of travel, and showing a state after the second connecting body has been rotated. [Figure 9] 1 is a hydraulic circuit diagram of a working machine according to an embodiment of the present invention. [Figure 10] 1 is a block diagram of a working machine according to an embodiment of the present invention. [Figure 11] FIG. 4 is an operation flow diagram of the working machine according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The mechanical structure of an embodiment of a working machine according to the present invention will be described with reference to Figs. A is a working machine. In this embodiment of the present invention, the working machine A relates to a working machine for performing work such as mowing. The working machine A has mounting parts 111, 112 for mounting attached to a traveling machine body (not shown) such as a tractor, and is driven. In this embodiment, the traveling machine body consisting of a tractor or the like is located behind the work machine A shown in FIG. 1, but the positional relationship between the traveling machine body and the work machine A in the front-rear direction is not limited.

[0014] Reference numeral 11 denotes a main frame. The main frame 11 is attached to the work machine A. As shown in the figure, the main frame 11 is provided with mounting parts 111 and 112 for mounting to the traveling machine body. The two parts 111 are mounting parts (lower) provided at the bottom, and 112 is a mounting part (top) provided at the top, and the work machine A is mounted to the traveling machine body at three points.

[0015] 1 and 2 denotes an input shaft. The input shaft 22 takes in driving force from a traveling machine body to which the input shaft 22 is attached to the working machine A. 1 denotes a transmission unit 23. In the transmission unit 23, the driving force input from the traveling machine body via the input shaft 22 is changed in speed.

[0016] 1 and 2, a hydraulic pump 24 is a fluid pressure generating source. The hydraulic pump 24 is driven by driving force input from the traveling machine body via an input shaft 22 and changed in speed by a transmission 23. The hydraulic pump 24 delivers hydraulic pressure to hydraulic devices operated by the hydraulic pressure of the work machine A. 1 and 2, a valve unit 25 is a directional control valve (directional control valve unit). The directional control valve 25 controls the switching of the flow of hydraulic pressure.

[0017] 1 and 2, a mast frame 21 is provided with a mast frame pivot shaft 211. The mast frame 21 is attached to the main frame 11 by the mast frame pivot shaft 211 so as to be freely rotatable. The mast frame 21 is provided at one end or the center of the main frame 11 of the work machine A relative to the left and right in the traveling direction. The mast frame 21 is capable of rotating the telescopic means 41 horizontally. The mast frame 21 is capable of rotating the telescopic means 41 around a mast frame rotation shaft 211, which is a vertical axis. By horizontally rotating the telescopic means 41 around the mast frame rotation shaft 211, the mast frame 21 can change its posture between a normal position where the telescopic means 41 is located on the left or right side in the traveling direction, and a retracted position where the telescopic means 41 is located on the rear side in the traveling direction.

[0018] Reference numeral 31 denotes a tank. In this embodiment, the tank 31 is an oil tank. The tank 31 is provided at the other end of the main frame 11 on the left and right sides in the traveling direction of the work machine A. Since each cylinder used in the work machine A is a hydraulic cylinder, the tank 31 stores oil for driving each oil cylinder.

[0019] Reference numeral 41 denotes telescopic means. The telescopic means 41 is made up of a boom device. The boom device is made up of a first boom 411 and a second boom 413. One end of the telescopic means 41 is connected to a rotatable mast frame 21 in the vicinity of the main frame 11. As shown in Figs. 1 and 2, the telescopic means 41 allows the working unit 51 to assume a stored state in which the telescopic means 41 is folded and the working unit 51 is positioned on the main frame 11, and a working state in which the telescopic means 41 is extended and the working unit 51 is positioned to the side of the main frame 11 in the traveling direction. That is, the extension means 41 can be changed between a stored state in which it is folded near the main frame 11 and an extended state in which it is extended to the side of the main frame 11. In the description, the extended state may be called a deployed state or a working state. The telescopic means 41 has a first boom 411, a first connector 412, a second boom 413, a second connector 414, a first cylinder 415, a second cylinder 416, a third cylinder 417, and a fourth cylinder 418. These cylinders, such as the first cylinder 415, the second cylinder 416, the third cylinder 417, and the fourth cylinder 418, are double-acting cylinders that rotate the boom.

[0020] The first boom 411 has one end connected to the mast frame 21 and is provided so as to be rotatable in the vertical direction. The first connector 412 has one end connected to the tip of the other end of the first boom 411 and is provided so as to be rotatable in the vertical direction. The second boom 413 has one end connected to the tip portion on the other end side of the first connector 412, and is provided so as to be rotatable in the forward and backward directions relative to the traveling direction when the mast frame 21 is in the normal position. The second connector 414 has one end provided at the tip portion on the other end side of the second boom 413, and is movable in parallel in the front-rear direction relative to the first connector 412 when the mast frame 21 is in the normal position.

[0021] The first cylinder 415 is made of a hydraulic cylinder, and connects the mast frame 21 and the first boom 411 via the first boom link mechanism 42 that connects the mast frame 21 and the first boom 411. The first cylinder 415 is for rotating the first boom 411 and is provided on the first boom 411. When the first cylinder 415 extends or retracts, it simultaneously rotates together with the first boom 411, causing the first boom 411 to rotate up and down. The first cylinder 415 drives the telescopic means 41 to rotate about a first boom rotating shaft 411A, which is a horizontal shaft provided on the mast frame 21. The first boom 411 is connected to the mast frame 21 so as to be rotatable in the vertical direction about a first boom rotation shaft 411A as a rotation center.

[0022] In the boom device consisting of the first boom 411 and the second boom 413, at least one of the booms is rotatable. The boom device consisting of the first boom 411 and the second boom 413 can rotate the base end side to move the working unit 51 located at the tip in the direction of travel up and down, left and right, and forward and backward to perform work. 1 and 2, the first boom 411 is supported by a first boom rotating shaft 411A which is a horizontal shaft and is rotatable about the horizontal shaft 411A. The first boom 411 is changeable between a stored state in which it is folded in the main frame 11 and an unfolded state in which it is rotated to the side of the main frame 11.

[0023] In Figs. 4, 5, 7 and 8, reference numeral 434 denotes a first fulcrum shaft, and reference numeral 435 denotes a second fulcrum shaft. The first fulcrum shaft 434 is provided at the tip portion on the other end side of the second boom 413, and the second fulcrum shaft 435 is provided on the second connector 414 connected to the first fulcrum shaft 434. The working unit 51 connected to the second connector 414 can rotate by the first fulcrum shaft 434 and the second fulcrum shaft 435. As shown by the arrows in Fig. 4, the left side of the figure is the front in the traveling direction, and the second boom 413 has moved forward and the second connector 414 has not yet rotated, Fig. 5, the left side of the figure is the front in the traveling direction, and the second boom 413 has moved forward and the second connector 414 has rotated, Fig. 7, the right side of the figure is the front in the traveling direction, and the second connector 414 has not yet rotated, and Fig. 8, the right side of the figure is the front in the traveling direction, and the second connector 414 has rotated, the first fulcrum shaft 434 is a rotation fulcrum shaft for a first circumferential direction which is the front-rear direction of the traveling direction of the working unit 51 in the second boom 413, and the regulating member 433 and the second connector rotate around the first fulcrum shaft 434 as shown by the arrows in these figures. A detailed description of the regulating member 433 will be given later.

[0024] 3, which shows the periphery of the main parts when the boom device is deployed, viewed from the front to the rear in the traveling direction, and as shown by the arrow, the second fulcrum shaft 435 is a rotation fulcrum shaft in a second circumferential direction that is the up-down direction of the working unit 51 relative to the second connecting body 414 of the second boom 413. The second fulcrum shaft 435 is a fulcrum part for the up-down rotation of the working unit 51. The first fulcrum axis 434 and the second fulcrum axis 435 are oriented to intersect with each other. The second boom 413 , which is a boom device, connects the second connector 414 via a first fulcrum shaft 434 .

[0025] The second boom 413, which is a boom device, is equipped with a second cylinder 416. The second cylinder 416 drives the second boom 413, which is a boom device, to swing in the left and right directions via the first connector 412. The second cylinder 416 is made of a hydraulic cylinder, and connects the first boom 411 to the other end side of the first connector 412. The second cylinder 416 is for rotating the first connector 412 up and down. The third cylinder 417 is a front-rear rotating cylinder, which is made of a hydraulic cylinder, and connects the first connector 412 and the second boom 413 together. The third cylinder 417 is for rotating the second boom 413 back and forth relative to the first boom 411. The third cylinder 417 rotates the telescopic means 41 back and forth in the traveling direction of the working unit 51 by extending and retracting the stroke when the mast frame 21 is in the normal position.

[0026] The fourth cylinder 418 is made of a hydraulic cylinder, and connects the second connector 414 and the working unit 51. The fourth cylinder 418 is for rotating the working unit 51 up and down. Each of the first cylinder 415, the second cylinder 416, the third cylinder 417, and the fourth cylinder 418 has a rod side chamber (415b, 416b, 417b, 418b) and a bottom side chamber (415a, 416a, 417a, 418a).

[0027] Reference numeral 51 denotes a working unit. The working unit 51 is provided at the tip end portion on the other end side of the second connecting body 414 and on the front side in the traveling direction of the second connecting body 414. The working unit 51 is further provided so as to be rotatable in the up and down direction with respect to the second connecting body 414 by a second fulcrum shaft 435. In this embodiment, when the mast frame 21 is in its normal position, the working unit 51 has multiple blade sections arranged on a rotation axis 512 facing in a direction perpendicular to the direction of travel, and performs tasks such as mowing grass by rotating the multiple blade sections.

[0028] 4, 5 and 6 denotes a second boom link member. The second boom 413, which is a boom device, is provided with a second boom link member 431. The second boom link member 431 is connected to the regulating member 433 so that the regulating member 433 is always oriented forward in the traveling direction. 4, 5 and 6 denotes a connection fulcrum of the second boom link member. The connection fulcrums 432 of the second boom link member are provided on both ends of the second boom link member 431. The connection fulcrums 432 of the second boom link member are rotatably attached to the first connector 412 and the restricting member 433, respectively. 6, reference numeral 436 denotes a second boom rotation fulcrum. The second boom rotation fulcrum 436 rotatably attaches the second boom 413 and the first connector 412, and causes the second boom 413 to rotate relative to the first connector 412.

[0029] As shown in FIG. 3, second connector 414 connects the tip of second boom 413, which is a boom device, to working unit 51. The working unit 51 is attached via a first boom 411, a first connector 412, a second boom 413, and a second connector 414. In detail, the working unit 51 is provided at the tip of the second boom 413 which rotates back and forth. One end side of the second connecting body 414 is rotatably attached to the tip of the second boom 413 in a first circumferential direction, which is the fore-and-aft direction of the second connecting body 414, by a first fulcrum axis 434, and the second connecting body 414 can rotate in the first circumferential direction relative to the second boom 413. The working unit 51 can rotate about a second fulcrum shaft 435 in a second circumferential direction, which is the up-down direction, relative to the second connecting body 414 by expansion and contraction of a fourth cylinder 418 provided on the second connecting body 414 .

[0030] 3 to 5, 7 and 8 denotes a restricting member 433. The restricting member 433 restricts the second connector 414 from turning in a first circumferential direction, which is the front-rear direction. The restricting member 433 is provided at the tip of the second boom 413 to which the second connector 414 is attached, so as to be rotatable coaxially with the first fulcrum shaft 434 in the first circumferential direction of the second connector 414. One end side of the regulating member 433 is connected to a second boom link member 431 provided inside the second boom 413. The regulating member 433 constitutes a parallel link mechanism together with the second boom 413, the first connector 412 connected to the base end of the second boom 413, and the second boom link member 431. As a result, even if the second boom 413 rotates back and forth, the regulating member 433 rotates in the first circumferential direction, and keeps a constant orientation of the regulating member 433 relative to the second boom 413. In the embodiment, the regulating member 433 can maintain its front-rear orientation with respect to the traveling direction. The restricting member 433 is covered by the second connector 414 .

[0031] 4, 5, 7 and 8 denotes a protruding portion 68. The protruding portion 68 is provided at the other end of the restricting member 433, that is, the free end with respect to the first fulcrum shaft 434. The second connector 414 has a space between the front and rear side plates, and the protrusion 68 is inserted into the space. 4, 5, 7 and 8, reference numeral 61 denotes a rear regulating member and 62 denotes a front regulating member. The rear regulating member 61 is formed from the rear part of the protruding portion 68 of the regulating member 433. The front regulating member 62 is formed from the front part of the protruding portion 68 of the regulating member 433. The second connector 414 can rotate in the first circumferential direction within a range in which the protrusions 68 contact both side plates spaced apart in the front-rear direction of the second connector 414. In other words, the protrusions 68 provided on the restricting member 433 restrict the second connector 414 from rotating in the first circumferential direction.

[0032] The working unit 51 connected to the second connector 414 can be rotated slightly within the angle range shown in Fig. 4 and Fig. 5, which is restricted by the restricting member 433 in the first circumferential direction, which is the front-rear direction of the traveling direction of the working unit 51. When the working unit 51 receives a load toward the rear, it rotates toward the rear, but since the rotation range is restricted, it is possible to work even in a position rotated toward the rear. In addition, the blade portion, which is the working part, is not exposed by the rear rotation, so there is no need to worry about foreign matter scattering, etc.

[0033] 4, 5, 7, and 8, the second connector 414 in the embodiment is restricted so that it can only swing forward and backward within a range of 0 to 5 degrees relative to the restricting member 433. This angle range can be adjusted according to the type of the work machine and the characteristics of the work site. The restricting member 433, particularly the protruding portion 68, is disposed so as to be hidden inside the second connecting body 414. For this reason, the angle range of the restricting member 433 between the protruding portion 68 and the second connecting body 414 is less susceptible to the influence of foreign matter, etc., and the working unit 51 can be stably operated.

[0034] In this embodiment of the present invention, since the second connecting body 414 and the working unit 51 do not pivot rearward significantly, there is no need to unnecessarily increase the strength of the components around the first fulcrum axis 434 and the second fulcrum axis 435, which are the pivot axes. In this embodiment of the present invention, the regulating member 433 is connected to the second boom link member 431 for forming a parallel link mechanism on the boom that rotates back and forth, but the regulating member 433 and the second connector 414 may be provided at the tip of a boom device that simply has a mechanism for rotating back and forth, or at the tip of a boom device that does not have a parallel link mechanism.

[0035] Reference numeral 64 denotes a biasing member. The biasing member 64 constantly biases the second connecting body 414 and the working body 51 toward the front side, which is one side, in a first circumferential direction, which is the front-rear direction relative to the regulating member 433. The regulating member 433 is provided with the biasing member 64. Reference numeral 63 denotes a guide rod. One end side of the guide rod 63 is connected to the second connecting body 414, supports the biasing member 64, and transmits the force of the biasing member 64 to the second connecting body 414. Therefore, when the load that the working unit 51 receives from the front increases, the second connecting body 414 and the working unit 51 rotate rearward against the biasing force of the biasing member 64. When the load decreases, the biasing force of the biasing member 64 returns the second connecting body 414 and the working unit 51 to their original positions.

[0036] Reference numeral 65 denotes a contact portion on the side of the restricting member 433. The contact portion 65 is provided on the restricting member 433 so as to face the end portion on the second connecting body 414 side. Reference numeral 66 denotes a contact portion on the second connecting body 414 side. The contact portion 66 is provided on the second connecting body 414 so as to face the contact portion 65 provided on the end portion of the restricting member 433 side. As shown in FIGS. 4 and 7, the biasing member 64 biases an abutting portion 65 on the restricting member 433 side and an abutting portion 66 on the second connecting body 414 side so as to abut against each other.

[0037] The detection unit w is provided on the restriction member 433. The detection unit w is provided on the restriction member 433 in the vicinity of the second connection body 414. A contact piece w1 is provided on the detection unit w, and comes into contact with the contact portion 66 on the second connecting body 414 side to sense contact. t is a control unit (not shown, see FIG. 10). Upon receiving the detection signal, the control unit t transmits an operation signal to the directional control valve 25 to operate the cylinder. An operating unit u (not shown) is provided on the traveling machine body and operates the directional control valve 25 via a control unit t.

[0038] The detection unit w detects the rotation of the second connecting body 414 in a first circumferential direction, which is the front-rear direction. In addition, as shown in FIG. 10, when a detection signal is detected, it is possible to issue a detection signal to a control unit t that controls the operation of the boom device. When the third cylinder 417 is extended, the second boom 413 rotates and moves forward, to the state shown in FIGS. When the working unit 51 is not subjected to a rearward load as shown in Figures 4 and 7, the front regulating portion 62 located in front of the protrusion 68 provided on the regulating member 433 does not come into contact with the front inner wall surface 414a of the front side plate of the second connecting body 414, and the rear regulating portion 61 located at the rear of the protrusion 68 comes into contact with the rear inner wall surface 414b of the rear side plate of the second connecting body 414. As shown in FIGS. 4 and 7, a contact portion 65 on the restricting member 433 side and a contact portion 66 on the second connecting body 414 side are pressed by the biasing force of the biasing member 64 into contact with each other.

[0039] When the working unit 51 connected to the second boom 413 via the second connecting body 414 comes into contact with a resistance such as an obstacle, as shown in Figures 5 and 8, the second connecting body 414 rotates relatively rearward in the first circumferential direction, which is the fore-and-aft direction of the regulating member 433. 5 and 8, due to the rotation, the front side regulating portion 62 located in front of the protruding portion 68 provided on the regulating member 433 comes into contact with the front side inner wall surface 414a of the second connecting body 414, and the rear side regulating portion 61 located in the rear of the protruding portion 68 comes into non-contact with the rear side inner wall surface 414b of the second connecting body 414. Note that the second connecting body 414 can be rotated relative to the regulating member 433 in the first circumferential direction even if the second boom 413 shown in FIGS. 4 to 8 does not rotate forward relative to the first connecting body 412. In other words, the second connecting body 414 can be rotated relative to the regulating member 433 regardless of the rotation position of the second boom 413. As shown in FIGS. 5 and 8, a contact portion 65 on the restricting member 433 side and a contact portion 66 on the second connecting body 414 side are not in contact with each other against the biasing force of the biasing member 64.

[0040] When the regulating member 433 rotates backward as shown in Figs. 5 and 8 within the first circumferential direction, which is the front-rear direction of the traveling direction of the working unit 51, the detection unit w detects a gap formed between the regulating member 433 and the second connecting body 414. When a gap is detected as shown in Figs. 5 and 8, the detection unit w issues a detection signal to the control unit t. The control unit t that receives the detection signal uses the detection signal for various controls. For example, it can perform operation control of a boom device to raise the working unit, display control to display on a display device that the working unit is under load, and notification control to notify the worker by voice or the like.

[0041] The detection unit w uses a switch that physically detects contact with the contact portion 66 of the second connecting body 414, but it is sufficient if it can detect the proximity distance between the contact portions 65 and 66, or the rotation angle. In other words, an optical or sonic distance detection sensor, angle sensor, or the like may be used.

[0042] When the control unit t receives no detection signal after transmitting the operation signal, it stops transmitting the operation signal to the directional control valve 25 to stop the operation of the cylinder. When the control unit t receives a detection signal from the detection unit w, it drives the first cylinder 415 to move the working unit upward together with the first boom 411 and the second boom 413. When the detection signal disappears, the control unit t controls to stop the upward movement. In addition, the control unit t may operate the second cylinder 416 to rotate the first connecting body 412 and move the working unit 51 laterally together with the second boom 413. Furthermore, the control unit t may operate the third cylinder 417 to rotate the second boom 413 in the forward / backward direction of the traveling direction of the working unit 51 and move the working unit 51 backward.

[0043] In this embodiment of the invention, the second fulcrum shaft 435, which is a pivot shaft for rotating the working unit 51 in the second circumferential direction, which is the up-down direction, works while facing the traveling direction. If the working unit 51 were structured to rotate widely without restriction in the first circumferential direction, which is the front-rear direction of the traveling direction, the second fulcrum shaft 435, which is a pivot shaft, would need to also handle loads in a direction intersecting the shaft. This would result in an increase in the weight of the components in order to improve the strength, which is not advisable from the perspective of weight balance when mounted on the traveling machine body.

[0044] A hydraulic circuit according to an embodiment of the present invention will be described with reference to FIG. c is the first relief valve (first pilot relief valve). The directional control valve 25 is made up of a first directional control valve 251, a second directional control valve 252, a third directional control valve 253, and a fourth directional control valve 254. The directional control valve 25 is a valve that operates by an electric signal, and its operation is controlled by a control unit t. Cylinder 415, cylinder 416, cylinder 417, and cylinder 418 are provided with directional control valve 25 for controlling the driving of the cylinders.

[0045] The directional control valve 25 controls the fluid flowing in and out of the cylinders 415, 416, 417, and 418 to either the direction in which the cylinders 415, 416, 417, and 418 extend or the direction in which the cylinders 415, 416, 417, and 418 contract. The first relief valve c is provided in the directional control valve 25. The first relief valve c has the function of automatically opening at a set pressure to reduce pressure. The first relief valve c is a pressure relief valve or a safety relief valve when abnormal pressure occurs in the fluid in the circuit inside the directional control valve 25.

[0046] The tank (oil tank) 31 is connected to the directional control valve 25 via the fluid pressure generating source 24, which is a hydraulic pump. Inside the directional control valve 25, the fourth directional control valve 254, the third directional control valve 253, the second directional control valve 252, and the first directional control valve 251 are connected in this order. The first directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254 in the directional control valve 25 are respectively connected to a first cylinder 415, a second cylinder 416, and a third cylinder 417 and a fourth cylinder 418 which are front-rear rotating cylinders, and to an unloading circuit (unloaded circuit) h which returns the fluid that has flowed into the first directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254 to the tank (oil tank) 31 when there is no operation by the operating unit u. The first cylinder 415 is connected to a directional control valve 25 that controls the fluid flowing in and out of the first cylinder 415. The first cylinder 415 controls the fluid flowing in and out of the first cylinder 415 by the directional control valve 25.

[0047] One end of the first relief valve c is connected to an unloading circuit h provided in the directional control valves 25 that are the first directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254, which are the directional control valves 25 that return oil to the tank (oil tank) 31 side, and The first relief valve c is connected to the first directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254, which are the directional control valve 25, via a first check valve 251a, a second check valve 252a, a third check valve 253a, and a fourth check valve 254a, which are capable of suppressing the inflow of fluid from the directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254 to the first relief valve c. The other end of the first relief valve c is connected to the tank (oil tank) 31.

[0048] As shown in FIG. 9, the first cylinder 415 has a rod side chamber 415b and a bottom side chamber 415a. The second cylinder 416 has a rod side chamber 416b and a bottom side chamber 416a. The third cylinder 417 has a rod side chamber 417b and a bottom side chamber 417a. The fourth cylinder 418 has a rod side chamber 418b and a bottom side chamber 418a.

[0049] The first direction control valve 251 is connected to the rod side chamber 415b and the bottom side chamber 415a of the first cylinder 415. The second direction control valve 252 is connected to the rod side chamber 416b and the bottom side chamber 416a of the second cylinder 416. The third direction control valve 253 is connected to the rod side chamber 417b and the bottom side chamber 417a of the third cylinder 417. The fourth direction control valve 254 is connected to the rod side chamber 418b and the bottom side chamber 418a of the fourth cylinder 418.

[0050] The first directional control valve 251 is configured so that a circuit leading from the first directional control valve 251 to the first cylinder 415 and a circuit leading from the first directional control valve 251 to the tank (oil tank) 31 can be connected.

[0051] The second directional control valve 252 is configured so that a circuit leading from the second directional control valve 252 to the second cylinder 416 and a circuit leading from the second directional control valve 252 to the tank (oil tank) 31 can be connected. The third directional control valve 253 is configured so that a circuit leading from the third directional control valve 253 to the third cylinder 417 and a circuit leading from the third directional control valve 253 to the tank (oil tank) 31 can be connected. The fourth directional control valve 254 is configured so that a circuit leading from the fourth directional control valve 254 to the fourth cylinder 418 and a circuit leading from the fourth directional control valve 254 to the tank (oil tank) 31 can be connected.

[0052] In this embodiment, the first directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254, which are the directional control valves 25 controlling the first cylinder 415 to the fourth cylinder 418, block the circuit within the first directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254, which are the directional control valves 25, so that the fluid transferred from the fluid pressure generating source 24 cannot flow in or out of the first cylinder 415 to the fourth cylinder 418 through the first directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254, which are the directional control valves 25, when no switching operation is performed by the operation unit u.

[0053] When a switching operation is performed using the operating unit u, the directional control valve 25 operates, allowing fluid to flow from the fluid pressure generating source 24 to the first cylinder 415 to the fourth cylinder 418, and allowing fluid to flow from the first cylinder 415 to the fourth cylinder 418 to the tank (oil tank) 31. Further, each of the directional control valves 25 used in this embodiment, that is, the first directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254, sends the fluid constantly transferred from the fluid pressure generating source 24 to the tank 31 via the unloading circuit h in a neutral state when not being operated.

[0054] The first directional control valve 251 has a circuit that runs from the first directional control valve 251 to a side of the tank 31 that is different from the unloading circuit h, and a circuit that connects the first directional control valve 251 to the first relief valve c and the unloading circuit h via a check valve 251a that is capable of suppressing the inflow of fluid to one end side of the first relief valve c. The second directional control valve 252 has a circuit that runs from the second directional control valve 252 to a side of the tank 31 that is different from the unloading circuit h, and a circuit that connects from the second directional control valve 252 to the first relief valve c and the unloading circuit h via a check valve 252a that is capable of suppressing the inflow of fluid to one end side of the first relief valve c.

[0055] The third directional control valve 253 has a circuit that runs from the third directional control valve 253 to the tank 31 side different from the unloading circuit h, and a circuit that connects from the third directional control valve 253 to the first relief valve c and the unloading circuit h via a check valve 253a that is capable of suppressing the inflow of fluid to one end side of the first relief valve c. The fourth directional control valve 254 has a circuit that runs from the fourth directional control valve 254 to the tank 31 side different from the unloading circuit h, and a circuit that connects from the fourth directional control valve 254 to the first relief valve c and the unloading circuit h via a check valve 254a that is capable of suppressing the inflow of fluid to one end side of the first relief valve c.

[0056] The rod side chamber 415b of the first cylinder 415 and the bottom side chamber 415a of the first cylinder 415 are each connected to the first directional control valve 251. Either the rod side chamber 415b or the bottom side chamber 415a of the first cylinder 415 is connected to the tank 31 by switching the first directional control valve 251. The first cylinder 415 controls the first directional control valve 251 to draw fluid into the bottom side chamber 415a and push fluid out of the rod side chamber 415b when the stroke is extended toward the stroke end, and to push fluid out of the bottom side chamber 415a and draw fluid into the rod side chamber 415b when the stroke is shortened. The first cylinder 415 can rotate the first boom 411 constituting the extension / contraction means 41 by extending or contracting the stroke, thereby raising or lowering the working unit 51. The extension and contraction of the first cylinder 415 is controlled by a directional control valve 25 having a first relief valve c.

[0057] The rod side chamber 416b of the second cylinder 416 and the bottom side chamber 416a of the second cylinder 416 are each connected to the second directional control valve 252. Either the rod side chamber 416b or the bottom side chamber 416a of the second cylinder 416 is connected to the tank 31 by switching the second directional control valve 252. The second cylinder 416 controls the second directional control valve 252 to draw fluid into the bottom side chamber 416a and push fluid out of the rod side chamber 416b when the stroke is extended toward the stroke end, and to push fluid out of the bottom side chamber 416a and draw fluid into the rod side chamber 416b when the stroke is shortened. The second cylinder 416 can rotate the first connecting body 412 constituting the extension / contraction means 41 by extending or contracting its stroke, thereby moving the working unit 51 upward or downward or in the left / right direction. The extension and contraction of the second cylinder 416 is controlled by a directional control valve 25 having a first relief valve c.

[0058] The rod side chamber 417b of the third cylinder 417 and the bottom side chamber 417a of the third cylinder 417 are each connected to the third directional control valve 253. Either the rod side chamber 417b or the bottom side chamber 417a of the third cylinder 417 is connected to the tank 31 by switching the third directional control valve 253. The third cylinder 417 controls the third directional control valve 253 to draw fluid into the bottom side chamber 417a and push fluid out of the rod side chamber 417b when the stroke is extended toward the stroke end, and to push fluid out of the bottom side chamber 417a and draw fluid into the rod side chamber 417b when the stroke is shortened. The third cylinder 417 rotates the second boom 413 constituting the extension / contraction means 41 in the forward / backward direction, which is the traveling direction of the working unit 51, by extending and contracting the stroke when the mast frame 21 is in the normal state. The extension and contraction of the third cylinder 417 is controlled by a directional control valve 25 having a first relief valve c.

[0059] The rod side chamber 418b of the fourth cylinder 418 and the bottom side chamber 418a of the fourth cylinder 418 are each connected to the fourth directional control valve 254. Either the rod side chamber 418b or the bottom side chamber 418a of the fourth cylinder 418 is connected to the tank 31 by switching the fourth directional control valve 254. The fourth cylinder 418 controls the fourth directional control valve 254 to draw fluid into the bottom side chamber 418a and push fluid out of the rod side chamber 418b when the stroke is extended toward the stroke end, and to push fluid out of the bottom side chamber 418a and draw fluid into the rod side chamber 418b when the stroke is shortened.

[0060] When the mast frame 21 is in a normal state, the fourth cylinder 418 rotates the working unit 51 in the vertical direction relative to the second connector 414 about the second fulcrum shaft 435 as a fulcrum by extending or contracting its stroke. The extension and contraction of the fourth cylinder 418 is controlled by a directional control valve 25 having a first relief valve c. The first cylinder 415, the second cylinder 416, the third cylinder 417, and the fourth cylinder 418 share the first relief valve c.

[0061] A control unit t shown in a block diagram of a work machine according to an embodiment of the present invention in Fig. 10 is connected to the directional control valve 25, the first directional control valve 251, the second directional control valve 252, the third directional control valve 253, and the fourth directional control valve 254, and controls the operations of these valves. As shown in Fig. 10, the control unit t is connected to a notification unit q, a display unit s, a receiving unit o, and a detection unit w. The control unit t receives an operation signal transmitted from the operation unit u by the actuation of the manually operated operating lever at the receiving unit o, and then uses this as an input operation signal and outputs a signal to the directional control valve 25 to operate the directional control valve 25.

[0062] Upon receiving an operation signal output from the control unit t, the directional control valve 25 operates the first directional control valve 251 to control the fluid flowing in and out of the first cylinder 415. Upon receiving a signal transmitted in response to the operation of the operation unit u, the control unit t controls the operation of the directional control valve 25 via the control unit t.

[0063] The control unit t that receives the operation signal outputs an operation signal for operating the directional control valve 251 . The directional control valve 251 that receives this operation signal switches the circuit to send fluid to the first cylinder 415 in order to raise or lower the working part 51 provided at the other end of the extension means 41 . In the embodiment, the raising of the working unit 51 switches the circuit to pump fluid from the directional control valve 251 to the bottom side chamber 415a, and the lowering of the working unit 51 switches the circuit to pump fluid from the directional control valve 251 to the rod side chamber 415b.

[0064] The operation and effects of the present invention will now be described. The directional control valve 25 can be switched to either the extending direction or the retracting direction of the first cylinder 415, the second cylinder 416, the third cylinder 417, and the fourth cylinder 418 to pump the fluid pressure generated by the pump 24 to the first cylinder 415, the second cylinder 416, the third cylinder 417, and the fourth cylinder 418, thereby driving each cylinder to extend and retract. In this embodiment, particular reference will be made to the operation of the directional control valve 25, the extending and retracting operation of the cylinder 415, and the circuit configuration related to these operations.

[0065] Based on the operation flow diagram shown in Figure 11, the detection unit w detects the gap formed between the regulating member 433 and the second connecting body 414 as shown in Figures 5 and 8 in the first circumferential direction, which is the front-to-rear direction of the traveling direction of the working unit 51, that is, the detection of the rearward movement of the second connecting body 414 when the regulating member 433 turns rearward, and the control by the control unit t will be described. In S1, it is determined whether or not contact is detected. If contact is not detected, the determination of whether or not contact is detected is repeated until contact is detected. When contact is detected in S1, the detector w generates a contact detection signal in S2. In S3, the control unit t receives the detection signal emitted by the detection unit w. In S4, upon receiving the detection signal, the control unit t instructs the directional control valve 25 to operate. In S5, it is determined whether or not contact has been detected by the detection unit w. If contact has been detected, the determination of whether or not contact has been detected is repeated. If contact has not been detected, the directional control valve 25 is instructed to stop operating. [Explanation of symbols]

[0066] 41 Telescopic means (boom device) 411 First Boom 413 Second Boom 414 2nd connector 433 Regulatory Materials 434 First Pivot Axis 435 Second Pivot Axis 51 Working Section 61 Rear side regulation part 62 Front side regulation part 64 Pressing member 68 Protrusion A Work equipment

Claims

1. A boom device having at least one rotatable boom; a working unit provided at a tip of the boom device, the working unit includes a connector that connects the boom device and the working unit, The boom device includes a fulcrum shaft that connects the connecting body and is provided so that the connecting body can rotate in a circumferential direction relative to the boom device; a detection unit provided adjacent to the connecting body, capable of detecting rotation of the fulcrum shaft of the working unit in a circumferential direction and capable of issuing a detection signal when the rotation is detected; a control unit that controls an operation of the boom device based on the detection signal; A work machine comprising:

2. When the control unit receives the detection signal, it transmits an operation signal for rotating the boom device.

2. The work machine according to claim 1 .

3. When the control unit does not receive the detection signal after transmitting the operation signal, the control unit stops transmitting the operation signal to stop the rotation operation of the boom device.

3. The work machine according to claim 2.

4. When the control unit receives the detection signal, the control unit performs display control to display on a display device that a load is being applied.

2. The work machine according to claim 1 .

5. When the control unit receives the detection signal, the control unit performs notification control to notify an operator by voice or the like.

2. The work machine according to claim 1 .

6. The boom device includes a cylinder for rotating the boom, The cylinder operates via a directional control valve that controls the actuation of the cylinder.

6. A work machine according to claim 1, wherein the work machine is a work machine having a first and second shafts.

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