Work equipment

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 more efficiently if only the working section of a work machine using a boom device or the like that performs the mowing work is positioned at a distance. One example is the work machine described in Patent Document 1, which is often used to mow grass, particularly on road shoulders and slopes. The invention described in Patent Document 1 has a buffer mechanism on the support arm that holds the working device main body, and this support arm has a bendable fulcrum. When a load greater than a predetermined level is applied to the fulcrum, the arm bends midway, causing the brush cutting device main body to move 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, if the support arm bends and the working part (the mower body) moves backward, the working part is not in the correct position and work cannot be continued. In order to continue work, the mower body that has moved backward must be returned to its reset position, which poses a problem of temporarily interrupting work. Furthermore, because the operator cannot know whether the load has reached the allowable limit, there is also the problem that the operator cannot take preventive measures such as avoiding obstacles or stopping the machine's movement. [Means for solving the problem]

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

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

[0007] The present invention further provides: When the control unit no longer receives 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 work machine characterized by: relates to.

[0008] The present invention further provides: 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 work machine characterized by: relates to.

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

[0010] The present invention further provides: 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 work machine characterized by: relates to. [Effects of the Invention]

[0011] An object of the present invention is to provide a work machine that is capable of detecting a load while still allowing work to continue. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a rear view of a working machine according to an embodiment of the present invention, showing a state in which a boom device is deployed, and a view from the rear in the direction of travel. [Figure 2] 1 is a plan view of a working machine according to an embodiment of the present invention when it is deployed, showing a state in which the boom device is in the deployed state and the working unit has been moved forward. [Figure 3] 1 is a front view of a working machine according to an embodiment of the present invention, showing the periphery of a main part when the boom device is deployed, as viewed from the front in the traveling direction to the rear side. [Figure 4] 1 is a partially enlarged cross-sectional view of a working machine according to an embodiment of the present invention, showing a cross-sectional side view 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. [Figure 5] 1 is a cross-sectional view of a working machine according to an embodiment of the present invention. A side cross-sectional view of a main part is shown. The left side of the figure is the front in the direction of travel. This shows the state after the second boom has moved forward and the second connecting body has rotated. [Figure 6] FIG. 1 is an enlarged partial cross-sectional view of a work machine according to an embodiment of the present invention. The figure shows a side cross-section of the area around the first connecting body. The left is the front in the direction of travel. The second boom is shown in a state where it has moved forward. There is no change before and after the second connecting body is rotated. [Figure 7]1 is a side view of a work machine according to an embodiment of the present invention, showing a restriction 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 before the second connecting body is rotated. [Figure 8] 1 is a side view of a work machine according to an embodiment of the present invention, showing the regulating portion as seen 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 work machine according to an embodiment of the present invention. [Figure 10] 1 is a block diagram of a work machine according to an embodiment of the present invention. [Figure 11] FIG. 3 is an operation flow diagram of the work machine according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[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 work machine. In this embodiment of the present invention, the work machine A relates to a work machine that performs work such as mowing. The work machine A is driven by mounting parts 111 and 112 attached to a traveling machine body (not shown) such as a tractor. In the embodiment, the traveling machine body, such as a tractor, 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 is not limited to the front-to-rear positional relationship.

[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 attachment parts 111 and 112 for attachment to the traveling machine body. The two parts 111 are attachment parts (lower) provided at the bottom, and 112 is an attachment part (top) provided at the top, and the work machine A is attached to the traveling machine body at three points.

[0015] 1 and 2 is an input shaft 22. The input shaft 22 takes in driving force from the traveling machine body to which it is attached to the work machine A. 1 is a transmission unit 23. The transmission unit 23 changes the speed of the driving force input from the traveling machine body via the input shaft 22.

[0016] 1 and 2, reference numeral 24 denotes a hydraulic pump which 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 equipment related to the work machine A which operates using hydraulic pressure. 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 shown. A mast frame pivot shaft 211 is shown. 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 in the left and right direction of travel. 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 rotating the telescopic means 41 horizontally 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 direction of travel, and a retracted position where the telescopic means 41 is located on the rear side in the direction of travel.

[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 direction of travel 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 near the main frame 11. As shown in Figures 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 direction of travel. 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 also be called an unfolded state or an operating 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 of the other end 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 of the other end side of the second boom 413, and is movable in parallel to the first connector 412 in the front-rear direction when the mast frame 21 is in the normal position.

[0021] The first cylinder 415 is made up 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 used to rotate 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 around a first boom rotation 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 around a first boom rotation shaft 411A as the center of rotation.

[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 perform work by rotating the base end side, thereby moving the working unit 51 located at the tip up and down, left and right, forward and backward in the direction of travel. 1 and 2, the first boom 411 is supported by a first boom rotation shaft 411A, which is a horizontal shaft, and is rotatable around the horizontal shaft 411A. The first boom 411 can be switched between a stored state in which it is folded into the main frame 11 and an unfolded state in which it is rotated to the side of the main frame 11.

[0023] 4, 5, 7 and 8, reference numeral 434 denotes a first fulcrum shaft, and 435 denotes a second fulcrum shaft. The first fulcrum shaft 434 is provided at the tip of the other end 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 in Fig. 4, the left side of the figure is the front in the direction of travel, and shows the second boom 413 moving forward and the second connector 414 in a state before pivoting; Fig. 5, the left side of the figure is the front in the direction of travel, and shows the second boom 413 moving forward and the second connector 414 in a state after pivoting; Fig. 7, the right side of the figure is the front in the direction of travel, and shows the second connector 414 in a state before pivoting; and Fig. 8, the right side of the figure is the front in the direction of travel, and shows the second connector 414 in a state after pivoting, the first fulcrum axis 434 is a rotation fulcrum axis for a first circumferential direction, which is the front-to-rear direction of the direction of travel of the working unit 51 on the second boom 413, and the restricting member 433 and the second connector rotate around the first fulcrum axis 434, as shown by the arrows in these figures. A detailed description of the restricting member 433 will be given later.

[0024] 3, which shows the periphery of the main parts of the boom device when deployed as viewed from the front to the rear in the direction of travel, the second fulcrum shaft 435 is a rotation fulcrum shaft in a second circumferential direction, which is the up-down direction of the working unit 51 relative to the second connecting body 414 of the second boom 413, as shown by the arrow. The second fulcrum shaft 435 is a fulcrum 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 connecting body 414 via the first fulcrum shaft 434 .

[0025] The second boom 413, which is a boom device, is provided 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. Second cylinder 416 is made up of a hydraulic cylinder, and connects first boom 411 and the other end side of first connector 412. Second cylinder 416 is used to rotate first connector 412 up and down. The third cylinder 417 is a front-rear rotating cylinder, and is made of a hydraulic cylinder, and connects the first connecting body 412 and the second boom 413 together. The third cylinder 417 is used to rotate 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 up of a hydraulic cylinder, and connects the second connector 414 and the working unit 51. The fourth cylinder 418 is used to rotate the working unit 51 up and down. The first cylinder 415, the second cylinder 416, the third cylinder 417, and the fourth cylinder 418 each have 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. Working unit 51 is provided at the tip end of the other end of second connecting body 414 and on the front side in the direction of travel of second connecting body 414. Working unit 51 is further provided so as to be rotatable in the up and down direction relative to 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 blades arranged on a rotation axis 512 that is oriented in a direction perpendicular to the direction of travel, and performs tasks such as mowing grass by rotating the multiple blades.

[0028] 4, 5, and 6 denotes a second boom link member. The second boom 413, which is a boom device, is provided with the second boom link member 431. The second boom link member 431 is connected to the restricting member 433 so that the restricting member 433 always faces forward in the traveling direction. 4, 5 and 6 designate the connection fulcrum of the second boom link member. The connection fulcrum 432 of the second boom link member is provided at each end of the second boom link member 431. The connection fulcrum 432 of the second boom link member is 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 allows 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 swings back and forth. One end of the second connecting body 414 is rotatably attached to the tip of the second boom 413 by a first fulcrum shaft 434 in a first circumferential direction, which is the fore-and-aft direction of the second connecting body 414, and the second connecting body 414 can rotate in the first circumferential direction relative to the second boom 413. Working unit 51 can rotate about second fulcrum shaft 435 in a second circumferential direction, which is the vertical direction relative to second connecting body 414, by expansion and contraction of fourth cylinder 418 provided on second connecting body 414.

[0030] 3 to 5, 7 and 8 designate a restricting member 433. The restricting member 433 restricts the second connecting body 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 of the second connector 414 in the first circumferential direction. One end of the restricting member 433 is connected to a second boom link member 431 provided inside the second boom 413. The restricting member 433 constitutes a parallel link mechanism together with the second boom 413, a first connector 412 connected to the base end of the second boom 413, and the second boom link member 431. As a result, even when second boom 413 rotates back and forth, regulating member 433 rotates in the first circumferential direction, thereby maintaining a constant orientation of regulating member 433 relative to second boom 413. In this embodiment, regulating member 433 can maintain its front-to-back orientation relative to the traveling direction. The restricting member 433 is covered by the second connecting body 414 .

[0031] 4, 5, 7 and 8 is a protrusion 68. The protrusion 68 is provided at the other end of the restricting member 433, that is, the free end relative 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-side regulating member and 62 denotes a front-side regulating member. The rear-side regulating member 61 is formed from the rear part of the protruding portion 68 of the regulating member 433. The front-side regulating member 62 is formed from the front part of the protruding portion 68 of the regulating member 433. The second connecting body 414 can rotate in the first circumferential direction within a range in which the protruding portions 68 contact both side plates spaced apart in the front-rear direction of the second connecting body 414. In other words, the protruding portions 68 provided on the restricting member 433 restrict the second connecting body 414 from rotating in the first circumferential direction.

[0032] The working unit 51 connected to the second connecting body 414 can be rotated slightly within the angular range shown in Figures 4 and 5, which is restricted by the restricting member 433 in the first circumferential direction, which is the forward / backward direction of the working unit 51. When the working unit 51 receives a load in the rearward direction, it will rotate rearward, but because the rotation range is restricted, it is still possible to work even in a position where it has rotated rearward. Furthermore, the blade, which is the working part, is not exposed by the rearward rotation, so there is no need to worry about foreign matter flying off.

[0033] In the case of the second connecting body 414 in this embodiment, as shown in Figures 4, 5, 7, and 8, it 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 depending on the type of work machine and the characteristics of the work site. The restricting member 433, particularly the protruding portion 68, is arranged so as to be hidden inside the second connecting body 414. Therefore, 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 operated stably.

[0034] In this embodiment of the present invention, the second connecting body 414 and the working unit 51 do not pivot rearward significantly, so 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 restricting member 433 is connected to the second boom link member 431 to form a parallel link mechanism on the boom that rotates back and forth, but the restricting member 433 and the second connecting body 414 may also be provided at the tip of a boom device that simply has a mechanism that rotates 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 forward, which is one side of a first circumferential direction that is the front-rear direction relative to the restricting member 433. The restricting member 433 is equipped with the biasing member 64. Reference numeral 63 denotes a guide rod. One end 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 received by the working unit 51 from the front increases, the second connecting body 414 and the working unit 51 pivot 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 side of second connecting body 414. Contact portion 66 is provided on second connecting body 414 so as to face contact portion 65 provided on the end portion of restriction member 433 side. As shown in FIGS. 4 and 7, the biasing member 64 biases the contact portion 65 on the restricting member 433 side and the contact portion 66 on the second connecting body 414 side so that they come into contact with each other.

[0037] The detecting portion w is provided on the restricting member 433. The detecting portion w is provided on the restricting member 433 in the vicinity of the second connecting body 414. w1 is a contact piece. The 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). When the control unit t receives the detection signal, it sends 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 direction control valve 25 via a control unit t.

[0038] The detection unit w detects the rotation of the second connecting body 414 in the 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, resulting in the state shown in FIGS. When the working part 51 is not subjected to a rearward load as shown in Figures 4 and 7, the front regulating part 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 part 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 Figures 4 and 7, the contact portion 65 on the regulating member 433 side and the contact portion 66 on the second connecting body 414 side are pressed into contact by the biasing force of the biasing member 64.

[0039] When the working unit 51 connected to the second boom 413 via the second connecting body 414 comes into contact with a resisting object such as an obstacle, the second connecting body 414 rotates relatively rearward within the first circumferential direction, which is the fore-and-aft direction of the regulating member 433, as shown in Figures 5 and 8. 5 and 8, due to the rotation, the front-side restricting portion 62 located in front of the protruding portion 68 provided on the restricting member 433 comes into contact with the front-side inner wall surface 414a of the second connecting body 414, and the rear-side restricting 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 restricting 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 restricting member 433 regardless of the rotational position of the second boom 413. As shown in Figures 5 and 8, the contact portion 65 on the regulating member 433 side and the 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 restricting member 433 rotates rearward in the first circumferential direction, which is the forward-backward direction of the traveling direction of the working unit 51, as shown in FIGS. 5 and 8, the detecting unit w detects a gap formed between the restricting member 433 and the second connecting body 414. When a gap is detected, as shown in FIGS. 5 and 8, the detecting unit w issues a detection signal to the control unit t. The control unit t that receives the detection signal uses the signal for various controls. For example, the detecting unit w can control the operation 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 senses contact with the abutment portion 66 of the second connecting body 414, but it is sufficient if it can detect the proximity distance or rotation angle between the abutment portions 65 and 66. In other words, an optical or sonic distance detection sensor, angle sensor, or the like may also be used.

[0042] When the control unit t no longer receives the 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 second boom 413. When the detection signal disappears, the control unit t stops the upward movement. Alternatively, it 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, it 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 present invention, the second fulcrum shaft 435, which is the pivot shaft that rotates the working unit 51 in the second circumferential direction, which is the up-and-down direction, works while facing the direction of travel. If the working unit 51 were designed to rotate freely and largely in the first circumferential direction, which is the front-to-back direction of the direction of travel, the second fulcrum shaft 435, which is the pivot shaft, would also need to be able to withstand loads in a direction intersecting the shaft. This would result in an increase in the weight of the components in order to improve strength, which is not advisable from the perspective of weight balance when attached to 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. Cylinders 415, 416, 417, and 418 are provided with directional control valves 25 that control the operation 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 extend or contract the cylinders 415, 416, 417, and 418, respectively. 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 or safety relief valve that releases pressure 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 direction control valve 251, the second direction control valve 252, the third direction control valve 253, and the fourth direction control valve 254 within the direction 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 (no-load circuit) h which returns the fluid that has flowed into the first direction control valve 251, the second direction control valve 252, the third direction control valve 253, and the fourth direction 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 via the directional control valve 25.

[0047] One end of the first relief valve c is connected to an unload circuit h provided in the directional control valves 25 that return oil from 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 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 directional control valves 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 direction control valve 251 is configured so that a circuit leading from the first direction control valve 251 to the first cylinder 415 and a circuit leading from the first direction control valve 251 to the tank (oil tank) 31 can be connected.

[0051] The second direction control valve 252 is configured so that a circuit leading from the second direction control valve 252 to the second cylinder 416 and a circuit leading from the second direction control valve 252 to the tank (oil tank) 31 can be connected. The third direction control valve 253 is configured so that a circuit leading from the third direction control valve 253 to the third cylinder 417 and a circuit leading from the third direction control valve 253 to the tank (oil tank) 31 can be connected. The fourth direction control valve 254 is configured so that a circuit leading from the fourth direction control valve 254 to the fourth cylinder 418 and a circuit leading from the fourth direction 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 that control 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 so that the fluid transferred from the fluid pressure generation 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 fluid to flow from the first cylinder 415 to the fourth cylinder 418 to the tank (oil tank) 31. Furthermore, 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 when in a neutral state when not in operation.

[0054] The first directional control valve 251 has a circuit that runs from the first directional control valve 251 toward the tank 31 side, which 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 can suppress the inflow of fluid toward one end of the first relief valve c. The second directional control valve 252 has a circuit that runs from the second directional control valve 252 toward the tank 31 side, which is different from the unloading circuit h, and a circuit that connects the second directional control valve 252 to the first relief valve c and the unloading circuit h via a check valve 252a that can suppress the inflow of fluid toward one end 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 toward the tank 31 side, which is different from the unloading circuit h, and a circuit that connects the third directional control valve 253 to the first relief valve c and the unloading circuit h via a check valve 253 a that can suppress the inflow of fluid toward one end of the first relief valve c. The fourth direction control valve 254 has a circuit that runs from the fourth direction control valve 254 toward the tank 31 side, which is different from the unloading circuit h, and a circuit that connects the fourth direction control valve 254 to the first relief valve c and the unloading circuit h via a check valve 254a that can suppress the inflow of fluid toward one end 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 direction 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 direction 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 rotates 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 direction 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 direction 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 rotates the first connecting body 412 constituting the extension / contraction means 41 by extending or contracting its stroke, thereby moving the working unit 51 up or down 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 direction 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 direction 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 direction of travel of the working unit 51, by extending or 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 direction 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 direction 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] 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 and contracting its stroke when the mast frame 21 is in the normal state. 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 Figure 10 is connected to and controls the operation of 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. As shown in Figure 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 operating unit u by the actuation of the manually operated operating lever at the receiving unit o, and then inputs this as an operation signal and outputs a signal to the directional control valve 25 to operate the directional control valve 25.

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

[0063] The control unit t receives the operation signal and outputs an operation signal to operate the directional control valve 251 . Upon receiving this operation signal, the directional control valve 251 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, raising of the working unit 51 switches the circuit so that fluid is pumped from the directional control valve 251 to the bottom side chamber 415a, and lowering of the working unit 51 switches the circuit so that fluid is pumped 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 between extending and retracting the first cylinder 415, the second cylinder 416, the third cylinder 417, and the fourth cylinder 418, thereby pumping 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 attention will be paid to the operation of the directional control valve 25, the operation of extending and retracting 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 forward and backward direction of the traveling direction of the working unit 51, i.e., when the regulating member 433 turns rearward, it detects the rearward movement of the second connecting body 414, and the control by the control unit t will be explained. 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 issues 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 components 434 First Support Axis 435 Second Support Axis 51 Working section 61 Rear side regulation part 62 Front side restricting part 64 biasing member 68 Protrusion A Work equipment

Claims

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

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

2. The work machine according to claim 1.

3. When the control unit no longer receives 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 the 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.

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