Work machine

Abstract

The present invention addresses the problem of attaining reductions in the number of parts and the cost while also improving safety.　The present invention has an attachment mounting part (36b) to which a coupling attachment (8) including a coupling hydraulic actuator (80) is mountable, includes a branch oil passage (L15) which branches off from a first oil passage (L6) connecting a control valve (60D) and a first hydraulic actuator (30a) and which can be connected to the coupling hydraulic actuator (80), and is switchable between a first state in which an on-off valve (63) for opening and closing the first oil passage (L6) is put into an open state, a coupling control valve (64) for opening and closing the branch oil passage (L15) is put into a closed state, and hydraulic oil from the control valve (60D) is supplied to the first hydraulic actuator (30a), and a second state in which the on-off valve (63) is put into a closed state, the coupling control valve (64) is put into an open state, and hydraulic oil from the control valve (60D) is supplied to the coupling hydraulic actuator (80).

Description

Work machine

[0001] The present invention relates to a work machine to which a connecting attachment for detachably attaching a work attachment can be attached.

[0002] Conventionally, a work machine to which a connecting attachment provided with a hydraulic actuator for detachably attaching a work attachment can be attached is known. (For example, see Patent Document 1).

[0003] Japanese Patent Laid-Open Publication "JP-A-2002-235335"

[0004] By providing a dedicated supply source as a supply source of hydraulic oil supplied to the hydraulic actuator of the connecting attachment, the number of parts and the cost increase. Therefore, it is conceivable to use the hydraulic oil supplied to other hydraulic actuators. However, in that case, there is a risk that other actuators may operate contrary to the intention of the operator when the hydraulic actuator of the connecting attachment operates.

[0005] Therefore, an object of the present invention is to reduce the number of parts and cost and improve safety in a work machine to which a hydraulically driven connecting attachment can be attached.

[0006] A work machine according to one aspect of the present invention has an attachment mounting portion to which a connecting attachment can be attached, which includes a connecting hydraulic actuator that can be switched between a connected state in which a work attachment is connected and a disconnected state in which the connection of the work attachment is released, and includes a control valve for controlling the supply and discharge of hydraulic fluid, a first oil passage connecting the control valve and a first hydraulic actuator, a branch oil passage branching from the first oil passage and connectable to the connecting hydraulic actuator, an on-off valve provided on the first hydraulic actuator side of the branch portion of the first oil passage with the branch oil passage and for opening and closing the first oil passage, and a connecting control valve for opening and closing the branch oil passage, and is switchable between a first state in which the on-off valve is in an open state and the connecting control valve is in a closed state and hydraulic fluid from the control valve is supplied to the first hydraulic actuator, and a second state in which the on-off valve is in a closed state and the connecting control valve is in an open state and hydraulic fluid from the control valve is supplied to the connecting hydraulic actuator.

[0007] According to the present invention, in a work machine that can be fitted with a hydraulically driven connecting attachment, it is possible to reduce the number of parts and costs, as well as improve safety.

[0008] Figure 1 is a perspective view from the front of a work machine according to one embodiment of the present invention. Figure 2 is an exploded perspective view from the front of the work machine according to the same embodiment. Figure 3 is a schematic side view of the attachment mounting section and the bucket, which is a work attachment, of the work machine according to the same embodiment. Figure 4 is a schematic side view of the attachment mounting section and the breaker, which is a work attachment, of the work machine according to the same embodiment. Figure 5 is a cross-sectional view of a connecting attachment attached to the attachment mounting section of the work machine according to the same embodiment. Figure 6 is a state diagram of a part of the system that operates the connecting attachment of the hydraulic system of the work machine according to the same embodiment, showing the state when the connection between the connecting attachment and the work attachment is released. Figure 7 is a state diagram of a part of the system that operates the connecting attachment of the hydraulic system of the work machine according to the same embodiment, showing the state when the connecting attachment and the work attachment are connected. Figure 8 is a block diagram of the control device of the work machine according to the same embodiment. Figure 9 is a schematic explanatory diagram of the hydraulic system of the work machine according to the same embodiment. Figure 10 is a schematic block diagram of the control valve unit in the hydraulic system of the work machine according to the same embodiment.

[0009] (1. Overall Configuration) One embodiment of the present invention will be described below. In this embodiment, the case in which the present invention is applied to a backhoe will be described, but it is not limited to this. The present invention can be applied to any work machine to which a work attachment can be detachably attached, and can be applied to construction machinery such as compact track loaders, skid rollers, and wheel loaders, or agricultural machinery such as tractors.

[0010] In the following explanation, the forward direction of the work machine is referred to as "forward," the backward direction as "rearward," the right side when facing forward is referred to as "rightward," and the left side when facing forward is referred to as "leftward."

[0011] As shown in Figures 1 and 2, the work machine 1 comprises left and right traveling devices 4, a machine body 2 rotatably supported by the traveling devices 4, and work devices 3a and 3b supported by the machine body 2.

[0012] Furthermore, as shown in Figure 2, the work machine 1 includes an operating unit 22 for the operator to operate the work devices 3a and 3b (left operating lever 22a for rotating the turntable 21, right operating lever 22b for operating the shovel device 3b, which will be described later as work device 3b, dozer operating lever 22c for operating the dozer device 3a, which will be described later as work device 3a), a travel lever 22d for operating the travel device 4, operating switches 23 and 24 (first operating switch 23, second operating switch 24) for operations related to the supply of hydraulic fluid to the first AUX port 61 (an AUX port (hydraulic fluid outlet port) that can supply hydraulic fluid to an external hydraulic device (work attachment) 9 equipped with a first hydraulic actuator 90, which will be described later), a monitor (notification device) 26 for displaying various information, and a control device 5 for controlling the travel device 4 and the work devices 3a and 3b, etc.

[0013] The machine body 2 comprises a travel base 20 connecting the left and right travel devices 4, and a turntable 21 that is rotatably supported on the travel base 20. The turntable 21 is equipped with an operator's seat DS where the operator sits, an operating unit 22 (left operating lever 22a, right operating lever 22b, dozer operating lever 22c) for the operator to operate the work devices 3a and 3b, a travel lever 22d, operating switches 23 and 24, a monitor (notification device) 26, a control device 5, and an operator's seat protection device 27 to protect the operator's seat DS (operator).

[0014] In this embodiment, the work machine 1 is equipped with a coupling operation switch 28 in addition to the above-mentioned operation switches 23 and 24 (first operation switch 23, second operation switch 24). The coupling operation switch 28 is an ON-OFF switch for operating the coupling attachment 8 (so-called quick coupler) described later. In this embodiment, the coupling operation switch 28 is located at the tip of the dozer operation lever 22c, but it is not limited to this and may be located at other positions.

[0015] The left operating lever 22a and the right operating lever 22b can be tilted forward, backward, left, and right. The left operating lever 22a controls the rotation of the machine body 2 (turntable 21) according to the direction and amount of tilt, and the right operating lever 22b controls the operation of the work device 3b according to the direction and amount of tilt. The dozer operating lever 22c can swing forward and backward, and controls the raising and lowering of the work device (dozer device) 3a according to the swing position.

[0016] In other words, the dozer operating lever 22c of the operating unit 22 operates the control valve (lifting cylinder control valve) 60D, which will be described later, according to the content of the operation, and changes the flow rate of the hydraulic fluid supplied from the control valve 60D. As will be described in detail later, in this embodiment, the dozer operating lever 22c can also be used to operate the connecting attachment 8, which will be described later.

[0017] A pair of travel levers 22d are provided, corresponding to the left and right travel devices 4, and by swinging them in the front-to-back direction, the forward and reverse (reverse) movement of the travel devices 4 is controlled.

[0018] The work machine 1 of this embodiment is equipped with two work devices 3a and 3b. One of the work devices 3a is a dozer device equipped with a lifting arm 31a pivotally supported on a travel base 20 so as to be able to swing around a horizontal axis, and a blade (dozer blade) 32a attached to the tip of the lifting arm 31a. The lifting arm 31a moves up and down around the horizontal axis by the extension and retraction of a lifting hydraulic actuator (hereinafter referred to as a lifting cylinder) 30a, which is a first hydraulic actuator.

[0019] The work machine 1 of this embodiment includes an operation switch (mode switching switch) 25 for switching the amount of hydraulic fluid that can be discharged from the first AUX port 61, a first operation switch 23 as an oil volume control switch for changing the amount of hydraulic fluid supplied to the first AUX port (hydraulic fluid outlet port) 61 (see Figure 1), and a second operation switch 24 as an oil volume control switch for changing the amount of hydraulic fluid supplied to the second AUX port (hydraulic fluid outlet port) 62 (see Figure 10).

[0020] In this embodiment, the first operation switch 23 is located on the upper part of the right operation lever 22b, the second operation switch 24 is located on the upper part of the left operation lever 22a, and the mode switching switch 25 is located on the control panel, each of which is operated by the operator with their fingers. In this embodiment, the mode switching switch 25 is an electrical ON-OFF switch, and an electrical signal is input to the control device 5 according to the operating position. In contrast, the first operation switch 23 and the second operation switch 24 use slide switches equipped with knob sensors, and a continuous value corresponding to the amount of operation is input to the control device 5.

[0021] The work device 3b includes an attachment mounting section 36b to which a work attachment 9 is detachably attached. Specifically, the other work device 3b includes a boom 34b that is rotatable (swings) around a vertical axis and rotatable around a first horizontal axis S1 relative to the slewing table 21, an arm 35b that is rotatably connected to the tip of the boom 34b around a second horizontal axis S2, and a work attachment 9 that is detachably attached to the attachment mounting section 36b provided at the tip of the arm 35b. Examples of work attachments 9 that can be attached to the attachment mounting section 36b include a bucket (see Figures 1, 2, and 3), a hydraulic crusher, a hydraulic breaker (see Figure 4), an angle broom, an earth auger, a pallet fork, a sweeper, a mower, a snowblower, etc. Furthermore, as shown in Figure 4, some work attachments 9 are equipped with a hydraulic actuator (hereinafter, the hydraulic actuator of the work attachment 9 will be referred to as the second hydraulic actuator) 90.

[0022] Figure 3 is a schematic side view showing an example where a bucket is attached as the work attachment 9, and Figure 4 is a schematic side view showing an example where a breaker is attached as the work attachment 9. As shown in Figures 3 and 4, the attachment mounting portion 36b includes a first link body 360 that connects the rod end of the work tool cylinder 32b (described later) to the arm 35b, and a second link body 361 that connects the rod end of the work tool cylinder 32b to the connecting portion 91 of the work attachment 9.

[0023] In the work machine 1 of this embodiment, the other work device 3b can have a connecting attachment 8 (see Figure 5) for detachably attaching a work attachment 9 attached to the arm 35b (attachment mounting portion 36b). That is, the work machine 1 can also directly attach the work attachment 9 to the arm 35b, but by attaching the connecting attachment 8 to the arm 35b, the attachment and detachment of the work attachment 9 becomes easier.

[0024] In this case, the other work device 3b includes a boom 34b that is rotatable (swings) around a vertical axis and rotatable around a first horizontal axis S1 relative to the turntable 21, an arm 35b that is rotatable around a second horizontal axis S2 relative to the tip of the boom 34b, and a connecting attachment 8 (see Figure 5) that is detachably attached to an attachment mounting portion 36b provided at the tip of the arm 35b.

[0025] Accordingly, the work machine 1 is equipped with a swing cylinder for swinging the boom 34b, a boom cylinder 30b for rotating the boom 34b around a horizontal axis S1, an arm cylinder 31b for rotating the arm 35b around a horizontal axis S2, and a work tool cylinder 32b for rotating the attachment mounting portion 36b around a horizontal axis S3, as a first hydraulic actuator for operating the other work device 3b.

[0026] As described above, the connecting attachment 8 is for attaching the work attachment 9 to the work device 3b in a replaceable manner by hydraulic operation. In this case as well, the work attachment 9 can be attached to the attachment mounting section 36b (arm 35b) via the connecting attachment 8, for example, a bucket (see Figure 3), a hydraulic crusher, a hydraulic breaker (see Figure 4), an angle broom, an earth auger, a pallet fork, a sweeper, a mower, a snow blower, etc.

[0027] (2. Configuration of the connecting attachment 8) Figure 5 is a longitudinal cross-sectional view of the connecting attachment 8. As shown in Figure 5, the connecting attachment 8 includes a connecting portion 81 that is connected to the attachment mounting portion 36b, and a connecting hydraulic actuator 80 that switches between a connected state in which the work attachment 9 is connected and a disconnected state in which the work attachment 9 is disconnected.

[0028] The attachment mounting portion 36b of the work device 3b includes a link body 361 (second link body 361) that connects the rod end of the work tool cylinder 32b to the connecting portion 81 of the connecting attachment 8. This link body 361 is connected to the rod end of the work tool cylinder 32b by an axis that is concentric (identical) to the axis that connects another link body 360 (first link body 360) that connects the arm 35b and the work tool cylinder 32b to the rod end of the work tool cylinder 32b. The connecting portion 81 of the connecting attachment 8 is connected to the tip of the link body 361 (second link body 361) and the tip of the arm 35b, respectively, via axes S3 and S4 that extend laterally. When the work attachment 9 is directly attached to the attachment mounting portion 36b, the connecting portion 91 of the work attachment 9 is also connected in the same manner as the connecting portion 81 of the connecting attachment 8.

[0029] As described above, the connecting attachment 8 has a connecting portion 81 that is connected to the attachment mounting portion 36b. The connecting portion 81 of the connecting attachment 8 is positioned to overlap laterally with the attachment mounting portion 36b (the tip of the link body 361 and the tip of the arm 35b), and the attachment can be connected to and disconnected from the attachment mounting portion 36b by inserting and removing shafts S3 and S4 into holes H1 and H2 provided in this overlapping portion. In other words, the connecting portion 81 of the connecting attachment 8, the tip of the link body 361, and the tip of the arm 35b (attachment mounting portion 36b) are provided with holes H1 and H2 that penetrate laterally. By inserting shafts S3 and S4 through the holes H1 and H2 so as to straddle the connecting portion 81 and the attachment mounting portion 36b, the connecting attachment 8 (connecting portion 81) is rotatably connected around the shaft S3 (hereinafter referred to as the third horizontal shaft S3) inserted through the hole H1 at the tip of the arm 35b.

[0030] The connecting attachment 8 comprises a first body 82 having a first shaft fitting portion 820 into which one of the two shafts S5, S5 provided on the connecting portion 91 of the work attachment 9 can be fitted; a fall prevention piece 83 for preventing the shaft S5 fitted into the first shaft fitting portion 820 from falling out; and a second body 84 having a second shaft fitting portion 840 into which the other shaft S5 of the two shafts S5, S5 can be fitted.

[0031] The first shaft fitting portion 820 and the second shaft fitting portion 840 are recesses that open laterally, allowing the shaft to be fitted through these openings. The first shaft fitting portion 820 and the second shaft fitting portion 840 open in opposite directions (reverse directions). The second body 84 is indirectly rotatably connected to the first body 82.

[0032] Specifically, the second body 84 is rotatably mounted around an axis S4 that connects the connecting portion 81 and the second link body 361, and is connected to the first body 82 via the connecting portion 81. As a result, the distance between the first shaft fitting portion 820 and the second shaft fitting portion 840 is changed by the relative rotation of the first body 82 and the second body 84 around axis S4. Specifically, the distance between the first shaft fitting portion 820 and the second shaft fitting portion 840 is configured to be switchable between a distance narrower than the distance between the two shafts S5, S5 fixed to the connecting portion 91 of the work attachment 9, and a distance in which both the two shafts S5, S5 fixed to the connecting portion 91 of the work attachment 9 are in a fitted state.

[0033] The anti-detachment piece 83 is provided so as to be able to extend and retract from the open portion of the first shaft fitting portion 820. In this embodiment, the anti-detachment piece 83 is fixed to the first body 82 via a support shaft S6 that extends laterally. That is, the anti-detachment piece 83 is provided so as to be able to rotate around the support shaft S6, and by rotating around the support shaft S6, it switches between a state in which it extends to the open portion of the first shaft fitting portion 820 and a state in which it is retracted from the open portion of the first shaft fitting portion 820.

[0034] Accordingly, the connecting attachment 8 has a connecting hydraulic actuator 80 that rotates the anti-detachment piece 83 and the second body 84. In this embodiment, the connecting hydraulic actuator 80 is a hydraulic cylinder that can extend and retract in a uniaxial direction and is positioned across the second body 84 and the anti-detachment piece 83. In this embodiment, the connecting hydraulic actuator 80 is a single-acting hydraulic cylinder that shortens when hydraulic fluid is supplied and extends when hydraulic fluid is discharged.

[0035] Specifically, the connecting hydraulic actuator 80 (hydraulic cylinder) includes a cylindrical cylinder body 800, a piston rod 801 including a piston 801a housed within the cylinder body 800 so as to be movable in the axial direction and a rod 801b that is continuous with the piston 801a and protrudes from one end of the cylinder body 800, and a coil spring 802 housed within the other end of the cylinder body 800 that biases the piston 801a toward one side of the cylinder body 800. One end of the cylinder body 800 is provided with a port for inflowing and outflowing hydraulic fluid, which is a port for connecting piping.

[0036] In the connecting hydraulic actuator 80, the tip (rod end) of the rod 801b is connected to the second body 84 via a laterally extending shaft S7, and the other end (cylinder end) of the cylinder body 800 is connected to the anti-detachment piece 83 via a laterally extending shaft S8. The connection position between the connecting hydraulic actuator 80 (hydraulic cylinder) and the anti-detachment piece 83 is set to an eccentric position with respect to the rotation center (pivot shaft S6) of the anti-detachment piece 83.

[0037] When hydraulic fluid is not supplied to the port, the connecting hydraulic actuator 80 is extended by the biasing force of the coil spring 802, which pushes the piston 801a toward one end of the cylinder body 800. When hydraulic fluid is supplied to the port, the piston 801a is pushed toward the other end of the cylinder body 800 against the biasing force of the coil spring 802, thereby shortening the actuator. In this embodiment, the connecting hydraulic actuator 80 can release the connection of the work attachment 9 when hydraulic fluid is supplied from the control valve 60D, and maintains the connection of the work attachment 9 by the biasing force of the coil spring 802 when hydraulic fluid is not supplied from the control valve 60D.

[0038] When the connecting hydraulic actuator 80 is extended, the anti-detachment piece 83 widens the gap between the first shaft fitting portion 820 and the second shaft fitting portion 840, and the shafts S5, S5 of the work attachment 9 engage with the first shaft fitting portion 820 and the second shaft fitting portion 840, allowing the work attachment 9 to be attached to the connecting attachment 8. On the other hand, when the connecting hydraulic actuator 80 is retracted, the gap between the first shaft fitting portion 820 and the second shaft fitting portion 840 narrows, allowing the shaft S5 to be inserted into and removed from the first shaft fitting portion 820 through the open portion of the first shaft fitting portion 820. As a result, the work attachment 9 is removed from the connecting attachment 8.

[0039] Figures 6 and 7 are explanatory diagrams showing the hydraulic circuit for driving the connecting attachment 8, with Figure 6 showing the unconnected state and Figure 7 showing the connected state. As shown in Figures 9 and 10, the work machine 1 is equipped with a hydraulic system 6 including a control valve unit CV that integrates a plurality of control valves 60A to 60L, but in Figures 6 and 7 only the control valve 60D (hereinafter referred to as the lifting cylinder control valve) which controls the supply and discharge of hydraulic fluid to the lifting cylinder 30a, which is a lifting hydraulic actuator that operates the dozer device 3a, is extracted and shown.

[0040] The pair of supply and discharge ports of the lifting cylinder control valve 60D, which controls the supply and discharge of fluid to and from the lifting cylinder 30a, are connected to the rod side and head side of the lifting cylinder 30a, respectively, via the first oil passage L6. The lifting cylinder control valve 60D can be switched between a neutral position, where the hydraulic fluid from the hydraulic pump flows downstream without supplying it to the lifting cylinder 30a; a first position, where the hydraulic fluid from the hydraulic pump is supplied to the rod side of the lifting cylinder 30a; and a second position, where the hydraulic fluid from the hydraulic pump is supplied to the head side of the lifting cylinder 30a. In addition, each first oil passage L6 is provided with an on-off valve 63 that opens and closes each first oil passage L6. The on-off valve 63 is a solenoid valve and opens and closes the first oil passage L6 according to the instructions of the control device 5, which will be described later.

[0041] Furthermore, one of the first oil passages L6 connecting the lifting cylinder control valve 60D and the lifting cylinder 30a (in this embodiment, the first oil passage L6 connected to the rod side of the lifting cylinder 30a) is connected to a branch oil passage L15 that is connected to a connecting hydraulic actuator 80 via a connecting control valve 64. The branch oil passage L15 is also provided with a connecting control valve 64 that opens and closes the branch oil passage L15. The connecting control valve 64 is a solenoid valve and, according to the instructions of the control device 5 described later, is switched between a supply position (disconnection position) that supplies hydraulic fluid supplied from the lifting cylinder control valve 60D via the first oil passages L6 and L15 to the connecting control valve 64 and a shut-off position (connection position) that shuts off the supply to the connecting control valve 64. Furthermore, the connecting control valve 64 is connected to the hydraulic oil tank T via a return oil passage L16. In the supply position, it shuts off the return oil passage L16 connecting the connecting hydraulic actuator 80 and the hydraulic oil tank T, and in the shut-off position, it connects the connecting hydraulic actuator 80 and the hydraulic oil tank T.

[0042] (3. Operation of the connecting attachment 8) As shown in Figure 8, the control device 5 is a so-called ECU (Electronic Control Unit). The control device 5 comprises an arithmetic control unit 50, a storage unit 51 that stores information used in the processing of the arithmetic control unit 50, an input unit 52 that receives input information from the outside, and an output unit 53 that outputs output signals from the arithmetic control unit 50 to the outside. The control device 5 generates control signals for controlling each part of the work machine 1 based on the input signals input from the input unit 52 and the information stored in the storage unit 51, and outputs them to each part to be controlled.

[0043] The arithmetic control unit 50 is a CPU (MPU) and includes an arithmetic unit 500 and a control unit 501. In the control device 5 of this embodiment, the storage unit 51 includes a first storage unit 510 that temporarily or short-term stores information used for processing by the arithmetic control unit 50 (arithmetic unit 500 and control unit 501), and a second storage unit 511 that long-term stores information used for processing by the arithmetic control unit 50 (arithmetic unit 500 and control unit 501). The first storage unit 510 is a so-called memory, and the second storage unit 511 is a storage device such as a hard disk or an SSD (Solid State Drive).

[0044] Input signals (electrical signals) are input to the input unit 52 from the operation unit 22, each operation switch 23, 24, 25, and various sensors provided in the working machine 1. Specifically, signals corresponding to operations on the operation unit 22 (left operation lever 22a, right operation lever 22b, dozer operation lever 22c, travel lever 22d) and the connection operation switch 28, as well as various sensors (pressure detection sensors, angle sensors, etc.) provided in the working machine 1, are input to the input unit 52. The output unit 53 outputs control signals to each part to be controlled. Specifically, signals for controlling the operations of each part of the working machine 1 (various hydraulic actuators, monitor 26, lighting device, audio output device, air conditioner, etc.) are output from the output unit 53.

[0045] The working machine 1 (control device 5) switches between a first state in which the hydraulic oil from the lift cylinder control valve 60D is supplied to the first hydraulic actuator 30a with the on-off valve 63 in the open state and the connection control valve 64 in the closed state, and a second state in which the hydraulic oil from the lift cylinder control valve 60D is supplied to the connection hydraulic actuator 80 with the on-off valve 63 in the closed state and the connection control valve 64 in the open state. In the present embodiment, when the operator operates the connection operation switch 28, a signal corresponding to the operation is input to the control device 5. The control device 5 operates the on-off valve 63 and the connection control valve 64 in accordance with the operation on the connection operation switch 28. Note that the connection operation switch 28 may be made operable only when the working machine 1 is in a predetermined state (for example, the traveling device 4 is not driven and the blade 32a of the working device 3a is disposed at a position corresponding to the neutral position of the dozer operation lever 22c), and the control device 5 may be prevented from operating the on-off valve 63 and the connection control valve 64 even if the connection operation switch 28 is operated when the working machine 1 is not in the predetermined state.

[0046] Specifically, when the connection operation switch 28 is turned on, the control device 5 operates the on-off valve 63 to the closed state and opens the connection control valve 64 (sets it to the second state). That is, when the connection operation switch 28 is turned on, the control device 5 operates the on-off valve 63 to the closed state and operates the connection control valve 64 to the supply position (connection release position) (sets it to the second state). At this time, the control device 5 may cause the monitor 26 to display that the operation mode of the connection attachment 8 or notify it by voice.

[0047] With the on-off valve 63 operated to the closed state and the connection control valve 64 in the supply position (connection release position), when the operator operates the dozer operation lever 22c, the lifting cylinder control valve 60D operates according to the lever operation, and the hydraulic oil from the outlet port of the lifting cylinder control valve 60D flows into the first oil passage L6. However, the hydraulic oil heading for the lifting cylinder 30a is blocked by the on-off valve 63 and is supplied to the connection hydraulic actuator 80 via the branch oil passage L15 and the connection control valve 64. As a result, hydraulic oil is supplied to one end side of the cylinder body 800 in the connection hydraulic actuator 80, and the piston 801a is pushed to the other end side, causing the connection hydraulic actuator 80 (hydraulic cylinder) to contract. As a result, the dropout prevention piece 83 and the second main body 84 rotate, the dropout prevention piece 83 retreats from the engagement position, and the shaft S5 at the connection portion 91 of the working attachment 9 disengages from the first shaft fitting portion 820 and the second shaft fitting portion 840.

[0048] Also, in this embodiment, when the connection operation switch 28 is turned off, the control device 5 operates the on-off valve 63 to the open state and operates the connection control valve 64 to the blocking position (connection position) (sets it to the first state). When attaching the working attachment 9, the operator first operates the working device 3b to position the first shaft fitting portion 820 and the second shaft fitting portion 840 of the connection attachment 8 at a position where they can be fitted to the shaft S5 of the connection portion 91 of the working attachment 9, and then turns off the connection operation switch 28.

[0049] As a result, the hydraulic fluid from the lifting cylinder control valve 60D is shut off by the connecting control valve 64 and is no longer supplied to the connecting hydraulic actuator 80, and the hydraulic fluid in the connecting hydraulic actuator 80 is discharged from the return oil passage L16 to the hydraulic fluid tank T. Consequently, the piston 801a of the connecting hydraulic actuator 80 is biased toward one end of the cylinder body 800 by the coil spring 802, causing the piston 801a to extend, and the shafts S5, S5 of the work attachment 9 are fitted into the first shaft fitting portion 820 and the second shaft fitting portion 840, connecting the work attachment 9 to the connecting attachment 8. Furthermore, when the connecting operation switch 28 is turned OFF, the on / off valve 63 opens, making the lifting cylinder 30a of the dozer device 3a operable.

[0050] In this embodiment, the connecting attachment 8 has a first shaft fitting portion 820 and a fall prevention piece 83, and the shaft S5 of the connecting portion 91 of the work attachment 9 is held by the combination of the first shaft fitting portion 820 and the fall prevention piece 83. However, the invention is not limited to this. For example, the connecting attachment 8 may be equipped with a hydraulic cylinder as a connecting hydraulic actuator 80, and the rod (piston rod) of the hydraulic cylinder or a shaft connected to the rod may be provided to be insertable and detachable into the hole of the connecting portion 91 of the work attachment 9. Furthermore, the connecting hydraulic actuator 80 is not limited to a single-acting hydraulic cylinder; a double-acting hydraulic cylinder or a hydraulic motor may also be used.

[0051] Furthermore, in this embodiment, the branch oil passage L15 is branched from the first oil passage L6 that supplies hydraulic fluid to the lifting cylinder 30a of the dozer device 3a, but it is not limited to this. That is, the branch oil passage L15 is branched from the first oil passage L6 that is connected to the lifting cylinder control valve 60D, but it is not limited to this. For example, an AUX port (hydraulic fluid outlet port) 61 capable of supplying hydraulic fluid to an external hydraulic device equipped with a hydraulic actuator may be provided, and the branch oil passage L15 may be branched from the oil passage that supplies hydraulic fluid to the AUX port 61 from a control valve that controls the supply and discharge of hydraulic fluid to the AUX port 61. Alternatively, a branched oil passage L15 may be branched from an oil passage connecting a plurality of first hydraulic actuators 30b, 31b, 32b… that drive the work device 3b (for example, first hydraulic actuators for performing any of the following actions: swinging, boom raising and lowering, arm raising and lowering, or work tool swinging) and a control valve that controls the supply and discharge of hydraulic fluid to the first hydraulic actuators 30b, 31b, 32b…. Furthermore, the operating unit 22 for operating the first hydraulic actuators 30b, 31b, 32b… corresponding to the oil passages connecting the branched oil passage L15 may be shared with the operating unit 22 for operating the connecting hydraulic actuator 80, or they may be separate.

[0052] Returning to Figure 5, the work machine 1 includes left and right travel motors M1 that drive the travel device 4, a slewing motor M2 that rotates the turntable 21, a lifting cylinder (first hydraulic actuator) 30a that swings the lifting arm 31a, a boom cylinder (first hydraulic actuator) 30b that swings the boom 34b around the horizontal axis S1, an arm cylinder (first hydraulic actuator) 31b that swings the arm 35b around the horizontal axis S2, a work tool cylinder (first hydraulic actuator) 32b that swings the work attachment 9 around the horizontal axis S3, and a swing cylinder (first hydraulic actuator) 33b that rotates (swings) the work device 3b (boom 34b) around the vertical axis. Accordingly, the work machine 1 is equipped with a hydraulic system 6 that can supply hydraulic fluid to each of the hydraulic actuators M1, M2, 30a...

[0053] As the notification device 26, for example, a monitor such as a liquid crystal display device is used, and the notification device 26 displays various information related to the work machine 1. In this embodiment, the notification device 26 provides notification in response to the operation of the mode switching switch 25. Specifically, when switching from the first mode to the second mode, as described later, the notification device 26 provides notification that it is switching to the second mode or that it has entered the second mode. In this embodiment, when the mode switching switch 25 is switched to the second mode, the notification device 26 provides notification that it is switching to the second mode or that it has entered the second mode.

[0054] More specifically, when the mode switching switch 25 is operated to switch to the second mode, the notification device 26 will provide a notification that the system is in the second mode for a predetermined period of time. Accordingly, the control device 5 will execute the switch to the second mode after the predetermined period of time has elapsed. In this embodiment, after the operation to switch to the second mode is performed, the notification device 26 will continue to provide a notification indicating that the system is in the second mode for at least a predetermined period of time. The purpose of continuing these notifications is to inform the operator that the system is in the second mode or is in the second mode (to wait for them to notice).

[0055] Therefore, instead of this, or in conjunction with this, if the mode switching switch 25 is operated to switch to the second mode, the notification device 26 may issue a notification to ask the worker whether it is permissible to switch to the second mode, and wait for the worker to approve switching to the second mode (perform the prescribed work).

[0056] Furthermore, if the mode selector switch 25 is operated to switch to the second mode while hydraulic fluid is being supplied to the second hydraulic actuator 90 of the work attachment 9 in the first mode, the notification device 26 will issue a notification indicating that mode switching is not possible. In conjunction with this, the control device 5 will prohibit mode switching. Also, in this embodiment, even if the mode selector switch 25 is operated to switch to the second mode while hydraulic fluid is being supplied to the second hydraulic actuator 90 of the work attachment 9 in the first mode, the control device 5 will prohibit (not execute) switching to the second mode.

[0057] In this embodiment, the notification device 26 is a monitor, and therefore the above notification is made by displaying at least one of characters and / or images. A touch panel may be used as the monitor, and an operation input unit for operator input may be provided separately from the monitor. However, in this embodiment, a touch panel is used as the monitor and functions as an operation input unit that receives operation input from the operator. Accordingly, in this embodiment, the monitor 26, which is the notification device 26, is connected to the input unit 52 and output unit 53 of the control device 5 (see Figure 8). Here, as described above, when a notification is made to ask the operator whether or not to switch to the second mode, the control device 5 may approve the switch to the second mode and execute the switch from the first mode to the second mode when a predetermined operation (input operation) is made to the operation input unit (notification device) 26.

[0058] The notification device 26 is not limited to a monitor; for example, it may be a speaker that provides voice notifications, a warning light or warning lamp that provides light notifications, or a combination of these.

[0059] (4. Hydraulic System 6) As shown in Figure 9, the hydraulic system 6 includes a hydraulic source that supplies hydraulic fluid to the hydraulic actuator, and the hydraulic source includes hydraulic pumps P1, P2, P3, P4 and control valves 60A to 60L. Specifically, the hydraulic system 6 includes a control valve unit CV having a plurality of hydraulic pumps P1, P2, P3, P4 that discharge hydraulic fluid and control valves 60A to 60L. Furthermore, as shown in Figures 9 and 10, the hydraulic system 6 includes the following oil passages connected to the control valve unit CV: an oil passage L4 connected to the second AUX port 62 (hydraulic oil outlet port), an oil passage L5 connected to the swing cylinder 33b, an oil passage L6 connected to the lifting cylinder 30a, an oil passage L7 connected to the slewing motor M2, an oil passage L8 connected to the first AUX port (hydraulic oil outlet port) 61, an oil passage L8a connected to this oil passage L8, an oil passage L9 connected to the arm cylinder 31b, an oil passage L10 connected to the right travel motor M1, an oil passage L11 connected to the left travel motor M1, an oil passage L12 connected to the boom cylinder 30b, an oil passage L13 connected to the work tool cylinder 32b, and an oil passage L14 connected to a variable leg cylinder (not shown) for changing the distance between the left and right travel devices. As will be described in detail later, the control valve unit CV includes the direction change control valves 60M, 60N, etc. as control valves (see Figure 10). Furthermore, the work machine 1 is equipped with a fourth hydraulic pump P4 that supplies pilot hydraulic fluid to control the operation of each control valve 60A to 60L (see Figure 9). The fourth hydraulic pump P4 is connected to an unload valve (not shown), pilot valves (not shown) corresponding to each control valve 60A to 60L, and ports (pressure receiving parts) for moving the spools of each control valve 60A to 60L.

[0060] The work machine 1 (hydraulic system 6) includes hydraulic oil outlet ports 61 and 62 to which a hydraulic oil supply passage for supplying hydraulic oil to the second hydraulic actuator 90 of the work attachment 9 can be connected. In this embodiment, the work machine 1 (hydraulic system 6) is provided with a first AUX port 61 and a second AUX port 62 as the hydraulic oil outlet ports 61 and 62. The first AUX port 61 and the second AUX port 62 are provided on the side surface near the tip of the arm 35b, and a hydraulic oil supply passage such as a hydraulic hose for supplying hydraulic oil to external hydraulic equipment (such as the hydraulic actuator (second hydraulic actuator) 90 of the work attachment 9) is detachably connected by a coupler or the like.

[0061] As shown in Figure 10, the control valve unit CV is formed by stacking multiple control valves 60A to 60L that constitute multiple hydraulic power sources.

[0062] Each of the control valves 60A to 60L has a pair of supply and discharge ports Eb, Eb for supplying and discharging hydraulic fluid to the corresponding hydraulic actuators M1, M2, 30a... Each of the control valves 60A to 60L can change the position of the spool within the housing to three positions: a neutral position, a first position located on one side of the neutral position, and a second position located on the other side of the neutral position. When the spool is in the neutral position, the hydraulic fluid that flows in from the primary side (hydraulic fluid inlet side) is discharged from the secondary side (hydraulic fluid outlet side) to the downstream control valve or hydraulic fluid tank T (see Figure 9) without passing through the hydraulic actuators M1, M2, 30a... When the spool is in the first position, hydraulic fluid is discharged from one of the pair of supply and discharge ports Eb to the corresponding hydraulic actuators M1, M2, 30a..., and the hydraulic fluid returning from the hydraulic actuators M1, M2, 30a... is received from the other supply and discharge port Eb and discharged into the hydraulic fluid tank T. When the spool is in the second position, hydraulic fluid is discharged from the other of the pair of supply and discharge ports Eb, and the hydraulic fluid returning from the hydraulic actuators M1, M2, 30a... is received from the other supply and discharge port Eb and discharged into the hydraulic fluid tank T.

[0063] There are several ways to operate the spools of each control valve 60A to 60L: (A) directly connecting the operating unit 22 (operating levers 22a, 22b, operating pedal, etc.) to the spool via a link or the like; (B) controlling the spool by controlling the pressure (pilot pressure) of the hydraulic fluid (pilot oil) from the fourth hydraulic pump P4 acting on the pressure receiving part of the control valve; and (C) connecting a solenoid (electromagnetic proportional valve) to the spool and operating the spool by operating the solenoid in accordance with an electrical signal. Furthermore, the method of operating the spool by pilot pressure (B) includes (B1) manually operating a pilot valve provided in the pilot oil passage using the operating unit 22, and (B2) electrically operating a solenoid provided in the pilot oil passage in accordance with the operation of the operating unit 22. In this embodiment, the case using method (B2) will be mainly described, but it is not limited to this. Also, the method of operating the spool may differ for each control valve.

[0064] The control valve unit CV has three inlet ports Ea1, Ea2, and Ea3 for receiving hydraulic fluid from the first hydraulic pump P1, the second hydraulic pump P2, and the third hydraulic pump P3, and a pilot hydraulic port (not shown) for receiving hydraulic fluid from the fourth hydraulic pump P4.

[0065] The hydraulic pumps P1 to P4 are driven by a power source such as an engine or electric motor, and draw hydraulic fluid from the hydraulic fluid tank T and discharge (supply) it to the control valve unit CV. In this embodiment, a multi-unit hydraulic pump (pump unit) PU is used as the hydraulic pumps P1 to P4, but it is not limited to this. In this embodiment, piston pumps (variable displacement pumps) are used as the second hydraulic pump P2 and the first hydraulic pump P1, and gear pumps (fixed displacement pumps) are used as the third hydraulic pump P3 and the fourth hydraulic pump P4, but the types of each hydraulic pump are not particularly limited.

[0066] The hydraulic system 6 includes three hydraulic sources (first hydraulic source, second hydraulic source, and third hydraulic source) that supply hydraulic fluid to the hydraulic actuators M1, M2, 30a...

[0067] The first hydraulic power source includes a first hydraulic pump P1 and a first control valve 60L that controls the supply and discharge of hydraulic fluid from the first hydraulic pump P1 to the first oil passage (AUX sub-oil passage described later) L8a. In this embodiment, the first hydraulic power source includes a first section group having a plurality of control valves 60I, 60J, 60K, 60L, including the first control valve 60L, which control the supply and discharge of hydraulic fluid to different hydraulic actuators M1, 30b, 32b, and a first hydraulic pump P1 that supplies hydraulic fluid to the first section group. In the hydraulic system 6, if multiple of the control valves 60I, 60J, 60K in the first section group are operated simultaneously, priority is given to the discharge of hydraulic fluid from control valves 60I, 60J other than the first control valve (first AUX sub-control valve described later) 60L. Specifically, the hydraulic fluid supplied from the first hydraulic pump P1 to the control valve unit CV via the inlet port Ea1 passes through the direction change control valve 60N and flows through the first section group consisting of control valves 60I, 60J, 60K, and 60L. That is, the hydraulic fluid from the first hydraulic pump P1 is sent through the first section group in the following order: the left travel motor control valve 60I for controlling the left travel motor M1, the boom cylinder control valve 60J for controlling the boom cylinder 30b, the bucket cylinder control valve 60K for controlling the work tool cylinder 32b, and the first AUX sub-control valve 60L for controlling the flow rate of the hydraulic fluid supplied to the first AUX port 61. Note that the control valves 60I, 60J, and 60K may be connected in series or in parallel with the first hydraulic pump P1, and the system may have both series-connected and parallel-connected control valves.

[0068] The second hydraulic power source includes a second hydraulic pump P2 and a second control valve 60F that controls the supply and discharge of hydraulic fluid from the second hydraulic pump P2 to the second oil passage (AUX main oil passage described later) L8. In this embodiment, the second hydraulic power source includes a second section group having a plurality of control valves 60H, 60G, 60F that control the supply and discharge of hydraulic fluid to different hydraulic actuators M1, 31b, 90, including a second control valve 60F, and a second hydraulic pump P2 that supplies hydraulic fluid to the second section group. If multiple of the control valves 60H, 60G, 60F in the second section group are operated simultaneously, the discharge of hydraulic fluid from control valves 60H, 60G other than the second control valve (first AUX main control valve described later) 60F is given priority. Specifically, the hydraulic fluid supplied from the second hydraulic pump P2 to the control valve unit CV via the inlet port Ea2 passes through the direction change control valve 60N and flows through the second section group consisting of control valves 60H, 60G, and 60F. The hydraulic fluid from the second hydraulic pump P2 is sent through the second section group in the following order: the right travel motor control valve 60H for controlling the right travel motor M1, the arm cylinder control valve 60G for controlling the arm cylinder 31b, and the first AUX main control valve 60F for controlling the second hydraulic actuator 90 of the work attachment 9 connected to the first AUX port 61. Note that the control valves 60H and 60G may be connected in series or in parallel with the second hydraulic pump P2.

[0069] The third hydraulic power source includes a third section group having a plurality of control valves 60A, 60B, 60C, 60D, 60E that control the supply and discharge of hydraulic fluid to different hydraulic actuators M2, 30a, and 33b, and a third hydraulic pump P3 that supplies hydraulic fluid to the third section group. The hydraulic fluid that has passed through the control valves 60A, 60B, 60C, 60D, 60E is supplied to the upstream side of the first AUX main control valve (second control valve) 60F, and the hydraulic fluid from the second hydraulic pump P2 and the hydraulic fluid from the third hydraulic pump P3 merge in the control valve unit CV and are supplied from the first AUX main control valve 60F to the first AUX port (hydraulic fluid outlet port) 61. In the hydraulic system 6, if any of the control valves 60A, 60B, 60C, 60D, or 60E within the third section group is operated, the discharge of hydraulic fluid from the other control valves 60A, 60B, 60C, or 60D takes precedence over the supply of hydraulic fluid to the second control valve (first AUX main control valve) 60F. The control valves 60A, 60B, 60C, 60D, or 60E may be connected in series or in parallel to the third hydraulic pump P3, and the system may have control valves connected in series and control valves connected in parallel.

[0070] Specifically, the hydraulic fluid supplied from the third hydraulic pump P3 to the control valve unit CV via the inlet port Ea3 flows through a third section group consisting of control valves 60A, 60B, 60C, 60D, and 60E, and is sent to the direction change control valve 60M. That is, the hydraulic fluid from the third hydraulic pump P3 is sent in the following order: second AUX control valve 60A for controlling the flow rate of hydraulic fluid supplied to the second AUX port 62, swing cylinder control valve 60B for controlling the swing cylinder 33b, variable leg cylinder control valve 60C for controlling the variable leg cylinder, lifting cylinder control valve 60D for controlling the lifting cylinder 30a of the dozer device 3a, slewing motor control valve 60E for controlling the slewing motor M2, and direction change control valve 60M for changing the direction of flow of the hydraulic fluid. The hydraulic fluid supplied to the direction change control valve 60M is available for supply to the primary port of the first AUX main control valve 60F. This allows the hydraulic fluid from the second hydraulic pump P2 and the hydraulic fluid from the third hydraulic pump P3 to be combined within the control valve unit CV and supplied to the first AUX port 61.

[0071] As described above, the first hydraulic source includes a first hydraulic pump P1 different from the second hydraulic pump P2, and a first control valve 60L that controls the supply and discharge of hydraulic fluid from the first hydraulic pump P1 to the downstream oil passage (second oil passage) L8a. The second hydraulic source includes a second hydraulic pump P2 that discharges hydraulic fluid, and a second control valve 60F that controls the supply and discharge of hydraulic fluid from the second hydraulic pump P2 to the downstream oil passage (second oil passage) L8. In the work machine 1 of this embodiment, the plurality of control valves 60A... of the control valve unit CV include a first control valve 60L that constitutes a first hydraulic source capable of supplying hydraulic fluid to the first AUX port 61, which is a hydraulic fluid outlet port, and a second control valve 60F that constitutes a second hydraulic source.

[0072] In this embodiment, the first control valve 60L and the second control valve 60F are integrally assembled in the control valve unit CV. That is, the control valve unit CV includes the first AUX main control valve 60F as the second control valve and the first AUX sub-control valve 60L as the first control valve.

[0073] The first AUX main control valve 60F is located at the downstream end of the second section group, and the first AUX sub-control valve 60L is located at the downstream end of the first section group.

[0074] The hydraulic system 6 includes an AUX main oil passage (second oil passage) L8 connecting a first AUX main control valve (second control valve) 60F to a first AUX port (hydraulic oil outlet port) 61, and an AUX sub-oil passage (first oil passage) L8a connecting a first AUX sub-control valve (first control valve) 60L to the first AUX port (hydraulic oil outlet port) 61 or the AUX main oil passage (second oil passage) L8. In this embodiment, the AUX sub-oil passage L8a connects the first AUX sub-control valve (first control valve) 60L to the AUX main oil passage L8.

[0075] As a result, the first AUX port 61 is connected to the first AUX main control valve 60F via the AUX main oil passage (second oil passage) L8, and to the first AUX sub-control valve 60L via the AUX sub-oil passage (first oil passage) L8a and the AUX main oil passage L8. This makes it possible to supply the first AUX port 61 with the hydraulic fluid from the first hydraulic pump P1 after combining it with the hydraulic fluid from the second hydraulic pump P2. In this embodiment, the hydraulic fluid from the second hydraulic pump P2 and the hydraulic fluid from the third hydraulic pump P3 are combined, and the hydraulic fluid from the first hydraulic pump P1 is also combined and supplied to the first AUX port 61. However, this is not the only option; for example, the hydraulic fluid from either the second hydraulic pump P2 or the third hydraulic pump P3 may be combined with the hydraulic fluid from the first hydraulic pump P1 and supplied to the first AUX port 61.

[0076] The AUX sub-oil passage L8a is composed of hydraulic piping and / or hydraulic hoses, and connects the supply / discharge port Eb corresponding to the control valve 60L to the first AUX port 61 outside the control valve unit CV. In this embodiment, the AUX sub-oil passage L8a is connected to the AUX main oil passage L8, but this is not limited to this configuration, and the AUX sub-oil passage L8a may be directly connected to the first AUX port 61.

[0077] In this embodiment, due to the flow path configuration, the second section group is positioned between the first section group and the third section group. However, the position of each section group is not limited to this, and they may, for example, be arranged in the order of the first section group, the second section group, and the third section group. In each section group, if multiple control valves within the same section group are operated, discharge from the upstream control valve takes precedence.

[0078] In this embodiment, the first AUX main control valve 60F is located at the downstream end of the second and third section groups, and the use of other hydraulic equipment belonging to the second and third section groups takes precedence over the driving of the second hydraulic actuator 90 by supplying hydraulic fluid from the first AUX main control valve 60F to the first AUX port 61. Furthermore, even when the first AUX sub-control valve 60L is provided at the downstream end of the first section group and hydraulic fluid from the first hydraulic pump P1 is supplied to the first AUX port 61, the use of other hydraulic equipment belonging to the first section group takes precedence over the driving of the second hydraulic actuator 90 by the first AUX port 61.

[0079] In the case of an open center circuit, the amount of hydraulic fluid discharged from the upstream control valve among the multiple control valves connected in series may change due to the operation of the actuator corresponding to the downstream control valve. Each control valve adjusts the flow rate to the actuator by varying the area of ​​the flow path that supplies the hydraulic fluid to the actuator corresponding to that control valve and the area of ​​the flow path that flows to the downstream control valve or tank. When an actuator is used on the downstream side, the pressure on the downstream side increases, making it more difficult for hydraulic fluid to flow from the upstream side to the downstream section, and as a result the amount of hydraulic fluid supplied to the upstream actuator increases.

[0080] Furthermore, in this embodiment, the left travel motor M1 is supplied with hydraulic fluid from the first hydraulic pump P1, and the right travel motor M1 is supplied with hydraulic fluid from the second hydraulic pump P2. When using an attachment that performs work while traveling (for example, a lawnmower) as the work attachment 9, the second hydraulic actuator 90 is driven while traveling. In this case, in a conventional work machine 1 that does not supply hydraulic fluid from the first hydraulic pump P1 to the second hydraulic actuator 90, the hydraulic fluid from the first hydraulic pump P1 is used only for the left travel motor M1, and the excess oil is returned to the hydraulic fluid tank T. On the other hand, the hydraulic fluid from the second hydraulic pump P2 is supplied to the right travel motor M1, and the excess oil not used by the right travel motor M1 is supplied to the second hydraulic actuator 90. Therefore, when traveling while using the second hydraulic actuator 90, the amount of hydraulic fluid supplied from the second hydraulic pump P2 to the right travel motor M1 becomes greater than the amount supplied to the left travel motor M1, resulting in a difference in the amount of hydraulic fluid supplied to the left and right travel motors M1, which may reduce straight-line stability.

[0081] In contrast, in this embodiment, since the hydraulic fluid from the first hydraulic pump P1 is also supplied to the second hydraulic actuator 90 from the downstream end of the first section group, the supply conditions for the hydraulic fluid from the first hydraulic pump P1 to the left travel motor M1 and the hydraulic fluid from the second hydraulic pump P2 to the right travel motor M1 can be made the amount of hydraulic fluid supplied equal, thereby improving straight-line stability during travel.

[0082] The combination of hydraulic actuators is not limited to the examples described above, and some may be omitted, replaced with other actuators, or additional actuators may be added. For example, the variable leg cylinder and variable leg cylinder control valve 60C, and / or the second AUX port 62 and second AUX control valve 60A may be omitted.

[0083] (5. Switching of flow rate of the first AUX port) The work machine 1 is configured to be switchable between a first mode in which the amount of hydraulic oil that can be supplied to the first AUX port (hydraulic oil outlet port) 61 is set to a predetermined supply amount, and a second mode in which the amount of hydraulic oil that can be supplied to the first AUX port (hydraulic oil outlet port) 61 is greater than the predetermined supply amount. In the first mode, the supply of hydraulic oil from the first AUX main control valve 60F (second hydraulic power source) to the first AUX port (hydraulic oil outlet port) is permitted, and the supply of hydraulic oil from the first AUX sub-control valve 60L (first hydraulic power source) to the first AUX port (hydraulic oil outlet port) is blocked. In contrast, in the second mode, the supply of hydraulic fluid from the first AUX main control valve 60F (second hydraulic source) to the first AUX port (hydraulic fluid outlet port) is permitted, and the supply of hydraulic fluid from the first AUX sub-control valve 60L (first hydraulic source) to the first AUX port (hydraulic fluid outlet port) is also permitted.

[0084] Let me explain in more detail. As described above, the work machine 1 is equipped with a mode switching switch 25 and a first operation switch 23.

[0085] The mode switching switch 25 is a switch for switching between a state in which hydraulic fluid from the first hydraulic pump P1 is not supplied to the first AUX port 61 (first mode; normal mode) and a state in which hydraulic fluid from the first hydraulic pump P1 is supplied to the first AUX port 61 (second mode; high flow mode). The flow rate used by the second hydraulic actuator 90 of the work attachment 9 differs for each actuator, with some requiring a high flow rate and others not being able to be used at a high flow rate. Therefore, in this embodiment, by providing the mode switching switch 25, it is possible to easily switch between the second mode, which allows a high flow rate of hydraulic fluid to be supplied to the second hydraulic actuator 90, and the first mode, which allows a smaller amount of hydraulic fluid to be supplied than the second mode, by operating the switch.

[0086] The first operating switch 23 is a switch for controlling the amount of hydraulic fluid supplied to the first AUX port 61. An electrical signal corresponding to the operating amount is input to the control device 5, thereby allowing the amount of hydraulic fluid supplied to be continuously changed according to the operating amount.

[0087] When the mode selector switch 25 is switched to the position corresponding to the first mode, the control device 5 moves the spool position of the first AUX main control valve 60F according to the operating position of the first operation switch 23, and maintains the first AUX sub-control valve 60L in the neutral position regardless of the operating position of the first operation switch 23. As a result, hydraulic fluid from the second hydraulic pump P2 and the third hydraulic pump P3 is supplied to the first AUX port 61 in an amount corresponding to the amount of operation of the first operation switch 23, while hydraulic fluid from the first hydraulic pump P1 is not supplied to the first AUX port 61 and is returned to the hydraulic fluid tank T.

[0088] On the other hand, when the mode switching switch 25 is switched to the position corresponding to the second mode, the control device 5 moves the spool position of the first AUX main control valve 60F and the spool position of the first AUX sub-control valve 60L according to the operating position of the first operating switch 23. As a result, the hydraulic fluid from the first hydraulic pump P1 merges with the hydraulic fluid from the second hydraulic pump P2 and the third hydraulic pump P3 and is supplied to the first AUX port 61. Therefore, in the second mode, the amount of hydraulic fluid that can be supplied to the first AUX port 61 can be increased compared to the first mode.

[0089] In this embodiment, the first AUX main control valve 60F and the first AUX sub-control valve 60L are equipped with electromagnetic proportional valves for operating the spool position. However, the system is not limited to this configuration. In the first mode, the first AUX sub-control valve 60L is kept in a state where no hydraulic fluid from the first hydraulic pump P1 is supplied to the first AUX port 61. In the second mode, the flow rate of hydraulic fluid supplied from the first AUX main control valve 60F and the first AUX sub-control valve 60L to the first AUX port 61 can be changed according to the operating position of the first operation switch 23.

[0090] Furthermore, the function to switch between the first and second modes is not mandatory. For example, the system may always be in a state corresponding to the second mode (a state in which the hydraulic fluids from the first hydraulic pump P1 to the third hydraulic pump P3 merge and are supplied to the second hydraulic actuator 90). In this case, for example, the control device 5 may control the operation of the first AUX main control valve 60F and the first AUX sub-control valve 60L so as to limit the maximum supply amount of hydraulic fluid according to the characteristics of the second hydraulic actuator 90.

[0091] (6. Warning Display) When the mode selector switch 25 is switched from the position corresponding to the first mode to the position corresponding to the second mode, the control device 5 causes the notification device 26 to display (notify) that the system has entered the second mode and / or that it will enter the second mode.

[0092] For example, when the mode switching switch 25 is switched from the position corresponding to the first mode to the second mode, the control device 5 causes the notification device 26 to notify that the system has entered the second mode, and in parallel with this, it performs a switching process to the second mode, which operates the first AUX sub-control valve 60L according to the operating position of the first operation switch 23. Once the switching process to the second mode is complete, the control device 5 causes the notification device 26 to notify that the system has entered the second mode. The notification that the system has entered the second mode may continue until the system switches back to the first mode.

[0093] Alternatively, when the mode switching switch 25 is switched from the position corresponding to the first mode to the second mode, the control device 5 may perform a switching process to the second mode in which the first AUX sub-control valve 60L operates according to the operating position of the first operation switch 23, and immediately after that, the notification device 26 may be notified that the system has entered the second mode.

[0094] Furthermore, when the mode switching switch 25 is switched from the position corresponding to the first mode to the second mode, the control device 5 may start the operation of the first AUX sub-control valve 60L in the second mode and also cause the notification device 26 to notify that the system has entered the second mode.

[0095] Furthermore, when the mode switching switch 25 is switched from the position corresponding to the first mode to the second mode, the control device 5 may cause the notification device 26 to display a message indicating that the system has entered the second mode for a predetermined period of time, and then start the operation of the first AUX sub-control valve 60L in the second mode after the predetermined period of time. In this case, after the operation of the first AUX sub-control valve 60L in the second mode has started, the notification device 26 may be instructed to notify that the system has entered the second mode.

[0096] Furthermore, when the mode switching switch 25 is switched from the position corresponding to the first mode to the second mode, the control device 5 may cause the notification device 26 to display (notify) a message inquiring whether or not it is possible to switch to the second mode, and if the operator performs a predetermined operation, the control device 5 may start the operation of the first AUX sub-control valve 60L in the second mode. In this case, after the operation of the first AUX sub-control valve 60L in the second mode has started, the control device 5 may cause the notification device 26 to notify that it has entered the second mode.

[0097] Furthermore, if the mode selector switch 25 is operated to switch to the second mode while hydraulic fluid is being supplied to the second hydraulic actuator 90 in the first mode, the control device 5 may choose not to perform the switch to the second mode. In other words, if the control device 5 wants the mode selector switch 25 to switch to the second mode while hydraulic fluid is being supplied to the second hydraulic actuator 90 in the first mode, it may be necessary to temporarily stop the supply of hydraulic fluid to the second hydraulic actuator 90 in the first mode before switching to the second mode is possible. In this case, the control device 5 may also cause the notification device 26 to provide a notification (switching impossible notification) indicating that the mode cannot be switched (or that the supply of hydraulic fluid to the second hydraulic actuator 90 needs to be temporarily stopped).

[0098] (7. Summary) The embodiments described above are as described above, and the present invention (preferred embodiment thereof) provides the work machine 1 described in the following items.

[0099] (Item 1-1) An attachment mounting section 36b to which a work attachment 9 including a hydraulic actuator 90 is detachably mounted, a hydraulic system 6 capable of supplying hydraulic fluid to the hydraulic actuator 90, and a notification device 26 for notifying the operator, wherein the hydraulic system 6 includes a hydraulic fluid outlet port 61 to which a hydraulic fluid supply passage for supplying hydraulic fluid to the hydraulic actuator 90 can be connected, and is configured to be switchable between a first mode in which the amount of hydraulic fluid that can be supplied to the hydraulic fluid outlet port 61 is a predetermined supply amount, and a second mode in which the amount of hydraulic fluid that can be supplied to the hydraulic fluid outlet port 61 is greater than the predetermined supply amount, and the notification device 26 notifies the operator that the operator is in the second mode or has entered the second mode, at least when switching to the second mode.

[0100] According to the work machine 1 of item 1-1, the hydraulic system 6 is configured to be switchable between a first mode in which the amount of hydraulic fluid supplied to the hydraulic fluid outlet port 61 is set to a predetermined amount, and a second mode in which the amount of hydraulic fluid supplied to the hydraulic fluid outlet port 61 is greater than the predetermined amount. Therefore, when the second mode is running, the amount of hydraulic fluid supplied (flow rate) to the hydraulic fluid outlet port 61 is greater than when the first mode is running.

[0101] As a result, the output of the hydraulic actuator of the work attachment 9 attached to the attachment mounting section 36b, which is connected to the hydraulic fluid outlet port 61, is greater when the second mode is running than when the first mode is running. Therefore, when the hydraulic system 6 switches from the first mode to the second mode, there is a risk that an unexpected change in output may occur for the operator. However, in the work machine 1 of item 1-1, the notification device 26 notifies the operator that the system is switching to the second mode or that the system has entered the second mode, at least when switching to the second mode, thus informing the operator of the increase in output of the work attachment 9 (hydraulic actuator).

[0102] Therefore, according to the work machine 1 of item 1-1, it is possible to ensure the safety of the worker while preventing the work attachment 9 from becoming underpowered.

[0103] (Item 1-2) The notification device 26 is a monitor and the work machine 1 described in Item 1-1 performs the notification by displaying at least one of characters and images.

[0104] According to the work machine 1 of item 1-2, the notification device 26 is a monitor and notifies the operator of at least one of either text or images, so that changes in the output of the work attachment 9 can be visually communicated to the operator.

[0105] (Item 1-3) The work machine 1 according to claim 1, comprising a mode switching switch 25 for an operator to switch between the first mode and the second mode, and a control device 5 that controls the switching between the first mode and the second mode in response to the operation of the mode switching switch 25, wherein the notification device 26 provides the notification in response to the operation of the mode switching switch 25.

[0106] According to the work machine 1 of item 1-3, the notification device 26 provides notification in response to the operation of the mode switching switch 25, thereby informing the worker of the output switching of the work attachment 9 (hydraulic actuator 90).

[0107] (Item 1-4) The work machine 1 as described in Item 1-3, wherein the control device 5 does not perform the switch to the second mode when the mode change switch 25 is operated to switch to the second mode while the control device 5 is supplying hydraulic fluid to the hydraulic actuator 90 in the first mode.

[0108] According to the work machine 1 of item 1-4, when the work attachment 9 is operating due to the supply of hydraulic fluid to the hydraulic actuator 90 of the work attachment 9, even if the mode switching switch 25 is switched to the second mode, the amount of hydraulic fluid supplied to the hydraulic actuator 90 does not increase, and the sudden increase in the operating speed of the work attachment 9 (hydraulic actuator 90) is prevented.

[0109] (Item 1-5) The work machine 1 as described in Item 1-4, wherein the notification device 26 provides a notification indicating that mode switching is not possible when the mode switching operation is performed on the mode switching switch 25 while the hydraulic actuator 90 is being supplied with hydraulic fluid in the first mode.

[0110] According to the work machine 1 of item 1-5, the notification device 26, when the hydraulic actuator 90 is being supplied with hydraulic fluid in the first mode, performs a mode switching operation on the mode switching switch to indicate that mode switching is not possible, as described in item 1-4.

[0111] According to the work machine 1 in item 1-5, the operator can recognize that they are unable to switch modes due to the notification from the notification device 26 that switching is not possible.

[0112] (Item 1-6) When the mode switching switch 25 is switched to the second mode, the notification device 26 notifies that the machine is in the second mode or has entered the second mode, and the control device 5 executes the switch to the second mode in parallel with the notification. The work machine 1 as described in Item 1-3.

[0113] According to the work machine 1 of item 1-6, the control device 5 switches to the second mode in parallel with notifying the operator that it will enter the second mode or that it has entered the second mode. Therefore, the worker recognizes that it has entered the second mode (the amount of hydraulic fluid supplied to the hydraulic actuator 90 increases) through the notification device 26, and the work attachment 9 (hydraulic actuator 90) increases speed at that time.

[0114] (Item 1-7) The work machine 1 according to Item 1-3, wherein when the mode switching switch 25 is switched to the second mode, the notification device 26 provides notification that the machine will enter the second mode for a predetermined period of time, and the control device 5 executes the switch to the second mode after the predetermined period of time has elapsed.

[0115] According to the work machine 1 of item 1-7, the control device 5 executes the switch to the second mode after the notification device 26 has given a notification for a predetermined time that it will enter the second mode. Therefore, the worker is given time (timing) to recognize the notification from the notification device 26 before entering the second mode, and the worker is less likely to overlook the notification from the notification device 26.

[0116] (Item 1-8) The work machine 1 according to Item 1-3, which is equipped with an operation input unit 26 that receives operation input from an operator, and when the mode switching switch 25 is switched to the second mode, the notification device 26 notifies the operator to ask whether it is acceptable to switch to the second mode, and the control device 5 executes the switch to the second mode when a predetermined operation to consent to switching to the second mode is performed on the operation input unit 26.

[0117] According to the work machine 1 of item 1-8, the notification device 26 notifies the worker whether or not to switch to the second mode, and the control device 5 executes the switch to the second mode when a predetermined operation is performed on the operation input unit 26 to consent to switching to the second mode, so that the mode can be switched according to the worker's will. In other words, it is prevented that the mode switch (the operating state of the hydraulic actuator) will be changed against the worker's will.

[0118] (Item 1-9) The work machine 1 according to Item 1-3, wherein the notification device 26 continues to provide notification indicating that it is in the second mode for at least a predetermined time after the operation to switch to the second mode has been performed.

[0119] According to the work machine 1 of item 1-9, a period of time is ensured for the worker to recognize the notification from the notification device 26.

[0120] (Item 1-10) A work machine 1 according to any one of items 1-1 to 1-9, comprising: a first hydraulic source and a second hydraulic source capable of supplying hydraulic fluid to the hydraulic fluid outlet port 61; a second oil passage L8 connecting the second hydraulic source and the hydraulic fluid outlet port 61; and a first oil passage L8a connecting the first hydraulic source and the hydraulic fluid outlet port 61 or the second oil passage L8, wherein in the first mode, the supply of hydraulic fluid from the second hydraulic source to the hydraulic fluid outlet port 61 is permitted and the supply of hydraulic fluid from the first hydraulic source to the hydraulic fluid outlet port 61 is blocked; and in the second mode, the supply of hydraulic fluid from the second hydraulic source to the hydraulic fluid outlet port 61 and the supply of hydraulic fluid from the first hydraulic source to the hydraulic fluid outlet port 61 are permitted.

[0121] According to the work machine of item 1-10, in the first mode, hydraulic fluid from the second hydraulic source is supplied to the hydraulic fluid outlet port 61 via the second oil passage L8, whereas in the second mode, hydraulic fluid from the second hydraulic source is supplied to the hydraulic fluid outlet port 61 via the second oil passage L8, and hydraulic fluid from the first hydraulic source is supplied to the hydraulic fluid outlet port 61 via the first oil passage L8a.

[0122] As a result, during the second mode, a larger amount of hydraulic fluid can be supplied to the hydraulic fluid outlet port 61 than during the first mode. Therefore, with the work machine 1 of item 1-10, it is possible to prevent the work attachment 9 from becoming underpowered.

[0123] (Item 1-11) The work machine 1 according to Item 1-10, wherein the first hydraulic source includes a first hydraulic pump P1 and a first control valve 60L that controls the supply and discharge of hydraulic fluid from the first hydraulic pump P1 to the first oil passage L8a, and the second hydraulic source includes a second hydraulic pump P2 and a second control valve 60F that controls the supply and discharge of hydraulic fluid from the second hydraulic pump P2 to the second oil passage L8, and in the first mode, the supply of hydraulic fluid from the first hydraulic pump P1 to the hydraulic fluid outlet port 61 is shut off by the first control valve 60L.

[0124] According to the work machine described in item 1-11, in the first mode, the supply of hydraulic fluid from the first hydraulic pump P1 to the hydraulic fluid outlet port 61 is shut off by the first control valve 60L, so that the hydraulic fluid to the work attachment 9 is supplied only from the second hydraulic source.

[0125] (Item 1-12) The work machine 1 according to Item 1-11, comprising an oil volume control switch 23 for an operator to control the flow rate of hydraulic fluid supplied from the hydraulic fluid outlet port 61 to the hydraulic actuator 90, wherein in the first mode, the flow rate of hydraulic fluid supplied from the hydraulic fluid outlet port 61 to the hydraulic actuator 90 is controlled by controlling the operation of the second control valve 60F in accordance with the operation of the oil volume control switch 23, and in the second mode, the flow rate of hydraulic fluid supplied from the hydraulic fluid outlet port 61 to the hydraulic actuator 90 is controlled by controlling the operation of the first control valve 60L and the second control valve 60F in accordance with the operation of the oil volume control switch 23.

[0126] According to the work machine described in item 1-12, since it is equipped with an oil volume control switch 23, the flow rate of the hydraulic fluid supplied to the hydraulic actuator 90 can be changed (adjusted) in both the first mode and the second mode.

[0127] (Item 1-13) The first hydraulic source includes a first section group having a plurality of control valves 60I, 60J, 60K for controlling the supply and discharge of hydraulic fluid to different hydraulic actuators M1, 30b, 32b, and is configured such that if multiple of the control valves 60I, 60J, 60K in the first section group are operated simultaneously, the discharge of hydraulic fluid from control valves 60I, 60J, 60K other than the first control valve 60L is prioritized. The second hydraulic source includes a second section group having a plurality of control valves 60F, 60G, 60H for controlling the supply and discharge of hydraulic fluid to different hydraulic actuators M1, 31b, 90, and is configured such that if multiple of the control valves 60F, 60G, 60H in the second section group are operated simultaneously, the discharge of hydraulic fluid from control valves 60H, 60G other than the second control valve 60F is prioritized. This is the work machine 1 described in Item 1-11 or Item 1-12.

[0128] According to the work machine described in item 1-13, the supply of hydraulic fluid to other hydraulic actuators is prioritized over the supply of hydraulic fluid to the hydraulic fluid outlet port 61, thereby suppressing the influence of the drive of the work attachment 9 on the operation of other hydraulic actuators.

[0129] (Item 1-14) The work machine 1 according to Item 1-13, having a control valve unit CV in which the first section group and the second section group are integrated, and the first oil passage L8a is provided outside the control valve unit CV.

[0130] According to the work machine described in item 1-14, the flow rate (output) of the hydraulic fluid at the hydraulic fluid outlet port 61 can be changed without complicating the flow path of the hydraulic fluid within the control valve unit CV.

[0131] (Item 1-15) The work machine 1 according to Item 1-13 or Item 1-14, comprising a third hydraulic source including a third section group having a plurality of control valves 60A, 60B, 60C, 60D, 60E that control the supply and discharge of hydraulic fluid to different hydraulic actuators M2, 30a, 33b, and a third hydraulic pump P3 that supplies hydraulic fluid to the third section group, wherein the hydraulic fluid that has passed through the third section group is supplied to the upstream side of the second control valve 60F, and the hydraulic fluid from the second hydraulic pump P2 and the hydraulic fluid from the third hydraulic pump P3 merge in the control valve unit CV and are supplied from the second control valve 60F to the hydraulic fluid outlet port 61.

[0132] According to the work machine described in item 1-15, the hydraulic fluid from the first hydraulic pump P1 and the second hydraulic pump P2, in addition to the hydraulic fluid from the third hydraulic pump P3, can be combined and supplied to the work attachment 9.

[0133] (Item 1-16) The work machine 1 according to Item 1-15, wherein when the control valves 60A, 60B, 60C, 60D, and 60E in the third section group are operated, the discharge of hydraulic fluid from the control valves 60A, 60B, 60C, 60D, and 60E takes precedence over the hydraulic fluid supplied from the third section to the second control valve 60F.

[0134] According to the work equipment of item 1-16, it is possible to suppress the influence of the drive of the work attachment 9 on the operation of other hydraulic actuators controlled by the control valve in the third section group.

[0135] (Item 1-17) A work machine 1 according to any one of items 1-1 to 1-16, comprising: a first hydraulic source and a second hydraulic source capable of supplying hydraulic fluid to the hydraulic fluid outlet port 61; a second oil passage L8 connecting the second hydraulic source and the hydraulic fluid outlet port 61; and a first oil passage L8 connecting the first hydraulic source and the hydraulic fluid outlet port 61 or the second oil passage L8a, wherein in the first mode, the supply of hydraulic fluid from the second hydraulic source to the hydraulic fluid outlet port 61 is permitted and the supply of hydraulic fluid from the first hydraulic source to the hydraulic fluid outlet port 61 is blocked; and in the second mode, the supply of hydraulic fluid from the second hydraulic source to the hydraulic fluid outlet port 61 and the supply of hydraulic fluid from the first hydraulic source to the hydraulic fluid outlet port 61 are permitted.

[0136] According to the work machine 1 of item 1-17, in the first mode, hydraulic fluid from the second hydraulic power source is supplied to the hydraulic fluid outlet port 61. In contrast, in the second mode, the hydraulic fluid from the first hydraulic power source and the hydraulic fluid from the second hydraulic power source merge and are supplied to the hydraulic fluid outlet port 61. As a result, in the second mode, a larger flow rate of hydraulic fluid is supplied to the hydraulic fluid outlet port 61 than in the first mode, which increases the output of the hydraulic actuator 90 to which the hydraulic fluid is supplied from the hydraulic fluid outlet port 61.

[0137] (Item 2-1) A work machine 1 having an attachment mounting portion 36b to which a connecting attachment 8 can be attached, which includes a connecting hydraulic actuator 80 that can be switched between a connected state in which a work attachment 9 is connected and a disconnected state in which the connection of the work attachment 9 is released, the work machine 1 having a control valve 60D that controls the supply and discharge of hydraulic fluid, a first oil passage L6 that connects the control valve 60D and a first hydraulic actuator 30a, a branch oil passage L15 that branches off from the first oil passage L6 and can be connected to the connecting hydraulic actuator 80, and the branch oil passage L in the first oil passage L6 The work machine 1 includes an on-off valve 63 provided on the side of the first hydraulic actuator 30a more than the branching point with 15 and for opening and closing the first oil passage L6, and a connecting control valve 64 for opening and closing the branch oil passage L15, and is switchable between a first state in which the on-off valve 63 is in an open state and the connecting control valve 64 is in a closed state, supplying hydraulic fluid from the control valve 60D to the first hydraulic actuator 30a, and a second state in which the on-off valve 63 is in a closed state and the connecting control valve 64 is in an open state, supplying hydraulic fluid from the control valve 60D to the connecting hydraulic actuator 80.

[0138] According to the work machine 1 of item 2-1, in the first state, hydraulic fluid is supplied to the first hydraulic actuator 30a, so that the first hydraulic actuator 30a can be operated. In contrast, in the second state, the hydraulic fluid that was supplied to the first hydraulic actuator 30a is no longer supplied to the first hydraulic actuator 30a, but is supplied to the connecting hydraulic actuator 80. As a result, with the first hydraulic actuator 30a stopped, the connecting attachment 8 can be switched between a connected state and a disconnected state. Therefore, according to the work machine 1 of item 2-1, the number of parts and costs can be reduced, and safety can be improved.

[0139] (Item 2-2) The work machine 1 described in Item 2-1, wherein the connecting hydraulic actuator 80 can release the connection of the work attachment 9 when hydraulic fluid is supplied from the control valve 60D, and maintains the connection of the work attachment 9 when hydraulic fluid is not supplied from the control valve 60D.

[0140] According to the work machine 1 in item 2-2, the supply of hydraulic fluid from the control valve 60D is only required when the connection is released, and the connection of the work attachment 9 does not need to rely on hydraulic fluid. As a result, even if a hydraulic fluid leak occurs, the work attachment 9 can be maintained in the connected state without being affected by the hydraulic fluid supply condition.

[0141] (Item 2-3) The work machine 1 according to Item 2-1, further comprising a coupling operation switch 28 for switching between the first state and the second state, and a control device 5 that controls the operation of the on-off valve 63 and the coupling control valve 64 in response to the operation of the coupling operation switch 28.

[0142] According to the work machine 1 in item 2-3, the connection operation switch 28 can be switched between the first state and the second state by the operator's intention, thus preventing accidental switching between the connected state and the disconnected state, and thus ensuring safety.

[0143] (Item 2-4) The work machine 1 according to Item 2-3, wherein when the operating state of the first hydraulic actuator 30a or the equipment driven by the first hydraulic actuator 30a is in a predetermined state, the on-off valve 63 and the connecting control valve 64 are operated in response to an operation on the connecting operation switch 28, while when the operating state is not the predetermined state, the on-off valve 63 and the connecting control valve 64 are not operated even if an operation is made on the connecting operation switch 28.

[0144] According to the work machine 1 of item 2-4, the coupling control valve 64 will not operate (will not switch to the first or second state) unless a predetermined state is reached, thus preventing unintentional coupling or becoming coupled.

[0145] (Item 2-5) The work machine 1 according to Item 2-1, comprising an operating unit 22 for operating the control valve 60D to change the flow rate of hydraulic fluid supplied from the control valve 60D, wherein in the first state the operating unit 22 operates the first hydraulic actuator 30a, and in the second state the operating unit 22 operates the connecting hydraulic actuator 80.

[0146] According to the work machine 1 of item 2-5, in both the first and second states, the first hydraulic actuator 30a or the connecting control valve 64 can be activated by operating the operating unit. In other words, operations corresponding to either the first or second state can be performed with the common operating unit 22 without providing a separate, independent operating unit.

[0147] (Item 2-6) The work machine 1 according to Item 2-1, comprising a machine body 2, a lifting arm 31a attached to the machine body 2, a dozer blade 32a attached to the tip of the lifting arm 31a, and a lifting hydraulic actuator 30a for raising and lowering the lifting arm 31a, wherein the first hydraulic actuator 30a is the lifting hydraulic actuator 30a.

[0148] According to the work machine 1 of item 2-6, in the first state, hydraulic fluid is supplied to the lifting hydraulic actuator 30a that raises and lowers the lifting arm 31a, so that the lifting arm 31a can be raised and lowered. In the second state, with the operation of raising and lowering the lifting arm 31a prohibited, the connecting attachment 8 can be switched between a connected state and a disconnected state.

[0149] (Item 2-7) The work machine 1 according to Item 2-1, having a hydraulic fluid outlet port 61 capable of supplying hydraulic fluid to an external hydraulic device equipped with the first hydraulic actuator 90, wherein the first oil passage L6 is an oil passage connecting the control valve 60D and the hydraulic fluid outlet port 61.

[0150] According to the work machine 1 of item 2-7, in the first state, hydraulic fluid is supplied to the external equipment via the hydraulic fluid outlet port 61, so that the external equipment can be operated, and in the second state, with the operation (operation) of the external equipment prohibited, the connecting attachment 8 can be switched between a connected state and a disconnected state.

[0151] (Item 2-8) The work machine 1 according to Item 2-1, comprising a machine body 2, a work device 3b having a boom 34b rotatably attached to the machine body 2, and an arm 35b rotatably attached to the boom 34b, wherein the first hydraulic actuator is a hydraulic actuator 30b, 31b, 32b that drives at least a part of the work device 3b.

[0152] According to the work device 1 of item 2-8, in the first state, hydraulic fluid is supplied to the hydraulic actuators 30b, 31b, and 32b that drive at least a part of the work device 3b, so that the work device 3b can be operated. In the second state, with the operation (movement) of the work device 3b prohibited, the connecting attachment 8 can be switched between a connected state and a disconnected state.

[0153] (Item 2-9) The work machine 1 according to Item 2-1, comprising a machine body 2, a boom 34b rotatably attached to the machine body 2, and an arm 35b rotatably attached to the boom 34b, wherein the attachment mounting portion 36b is provided on the arm 35b.

[0154] According to the work machine 1 of item 2-9, since the arm 35b is provided with an attachment mounting portion 36b, the connecting attachment 8 is attached to the tip of the arm 35b. This allows the position of the connecting attachment 8 to be changed by rotating at least one of the boom 34b and the arm 35b, and facilitates the operation of connecting the work attachment 9 to the connecting attachment 8.

[0155] (Item 3-1) A work machine 1 comprising: an attachment mounting section 36b to which a work attachment 9 including a hydraulic actuator 90 is detachably mounted; a hydraulic oil outlet port 61 to which a hydraulic oil supply passage for supplying hydraulic oil to the hydraulic actuator 90 can be connected; a first hydraulic source and a second hydraulic source capable of supplying hydraulic oil to the hydraulic oil outlet port 61; a second oil passage L8 connecting the second hydraulic source and the hydraulic oil outlet port 61; and a first oil passage L8a connecting the first hydraulic source and the hydraulic oil outlet port 61 or the second oil passage L8, wherein the work machine 1 is switchable between a first mode that allows the supply of hydraulic oil from the second hydraulic source to the hydraulic oil outlet port 61 and blocks the supply of hydraulic oil from the first hydraulic source to the hydraulic oil outlet port 61; and a second mode that allows the supply of hydraulic oil from the second hydraulic source to the hydraulic oil outlet port 61 and the supply of hydraulic oil from the first hydraulic source to the hydraulic oil outlet port 61.

[0156] According to the work machine 1 of item 3-1, in the first mode, hydraulic fluid from the second hydraulic source is supplied to the hydraulic fluid outlet port 61 via the second oil passage L8, whereas in the second mode, hydraulic fluid from the second hydraulic source is supplied to the hydraulic fluid outlet port 61 via the second oil passage L8, and hydraulic fluid from the first hydraulic source is supplied to the hydraulic fluid outlet port 61 via the first oil passage L8a.

[0157] As a result, during the second mode, a larger amount of hydraulic fluid can be supplied to the hydraulic fluid outlet port 61 than during the first mode. Therefore, with the work machine 1 of item 3-1, it is possible to prevent the work attachment 9 from experiencing insufficient output.

[0158] (Item 3-2) The work machine 1 according to Item 3-1, wherein the first hydraulic power source includes a first hydraulic pump P1 and a first control valve 60L that controls the supply and discharge of hydraulic fluid from the first hydraulic pump P1 to the first oil passage L8a, and the second hydraulic power source includes a second hydraulic pump P2 and a second control valve 60F that controls the supply and discharge of hydraulic fluid from the second hydraulic pump P2 to the second oil passage L8, and in the first mode, the supply of hydraulic fluid from the first hydraulic pump P1 to the hydraulic fluid outlet port 61 is shut off by the first control valve 60L.

[0159] According to the work machine 1 of item 3-2, in the first mode, the supply of hydraulic fluid from the first hydraulic pump P1 to the hydraulic fluid outlet port 61 is shut off by the first control valve 60L, so that the hydraulic fluid to the work attachment 9 is supplied only from the second hydraulic source.

[0160] (Item 3-3) The work machine 1 according to Item 3-2, which is equipped with an oil volume control switch 23 for an operator to control the flow rate of hydraulic fluid supplied from the hydraulic fluid outlet port 61 to the hydraulic actuator 90, wherein in the first mode, the flow rate of hydraulic fluid supplied from the hydraulic fluid outlet port 61 to the hydraulic actuator 90 is controlled by controlling the operation of the second control valve 60F in accordance with the operation of the oil volume control switch 23, and in the second mode, the flow rate of hydraulic fluid supplied from the hydraulic fluid outlet port 61 to the hydraulic actuator 90 is controlled by controlling the operation of the first control valve 60L and the second control valve 60F in accordance with the operation of the oil volume control switch 23.

[0161] According to the work machine 1 of item 3-3, since it is equipped with an oil volume control switch 23, the flow rate of the hydraulic fluid supplied to the hydraulic actuator 90 can be changed (adjusted) in both the first mode and the second mode.

[0162] (Item 3-4) The work machine 1 according to any one of items 3-1 to 3-3, which is equipped with a mode switching switch 25 for the operator to switch between the first mode and the second mode.

[0163] According to the work machine 1 in item 3-4, the operator can switch between the first mode and the second mode by operating the mode switching switch 25 based on the operator's will.

[0164] (Item 3-5) The first hydraulic source includes a first section group having a plurality of control valves 60I, 60J, 60K for supplying and discharging hydraulic fluid to different hydraulic actuators M1, 30b, 32b, and is configured such that if multiple of the control valves 60I, 60J, 60K in the first section group are operated simultaneously, the discharge of hydraulic fluid from control valves 60I, 60J, 60K other than the first control valve 60L takes precedence. The second hydraulic source includes a second section group having a plurality of control valves 60F, 60G, 60H for supplying and discharging hydraulic fluid to different hydraulic actuators M1, 31b, 90, and is configured such that if multiple of the control valves 60F, 60G, 60H in the second section group are operated simultaneously, the discharge of hydraulic fluid from control valves 60H, 60G other than the second control valve 60F takes precedence. The work machine 1 described in any one of items 3-2 to 3-4, which is subordinate to item 3-2.

[0165] According to the work machine 1 of item 3-5, the supply of hydraulic fluid to other hydraulic actuators is prioritized over the supply of hydraulic fluid to the hydraulic fluid outlet port 61, thereby suppressing the effect of the drive of the work attachment 9 on the operation of other hydraulic actuators.

[0166] (Item 3-6) The work machine 1 according to Item 3-5, having a control valve unit CV in which the first section group and the second section group are integrated, and the first oil passage L8a is provided outside the control valve unit CV.

[0167] According to the work machine 1 in item 3-6, the flow rate (output) of the hydraulic fluid at the hydraulic fluid outlet port 61 can be changed without complicating the flow path of the hydraulic fluid within the control valve unit CV.

[0168] (Item 3-7) The work machine 1 according to Item 3-5 or Item 3-6, comprising a third hydraulic source including a third section group having a plurality of control valves 60A, 60B, 60C, 60D, 60E that control the supply and discharge of hydraulic fluid to different hydraulic actuators M2, 30a, 33b, and a third hydraulic pump P3 that supplies hydraulic fluid to the third section group, wherein the hydraulic fluid that has passed through the third section group is supplied to the upstream side of the second control valve 60F, and the hydraulic fluid from the second hydraulic pump P2 and the hydraulic fluid from the third hydraulic pump P3 merge in the control valve unit CV and are supplied from the second control valve 60F to the hydraulic fluid outlet port 61.

[0169] According to the work machine 1 of item 3-7, the hydraulic fluid from the first hydraulic pump P1 and the second hydraulic pump P2, in addition to the hydraulic fluid from the third hydraulic pump P3, can be combined and supplied to the work attachment 9.

[0170] (Item 3-8) The work machine according to Item 3-7, wherein when the control valves 60A, 60B, 60C, 60D, and 60E in the third section group are operated, the discharge of hydraulic fluid from the control valves 60A, 60B, 60C, 60D, and 60E takes precedence over the hydraulic fluid supplied from the third section to the second control valve 60F.

[0171] According to the work equipment described in item 3-8, the driving of the work attachment 9 can be prevented from affecting the operation of other hydraulic actuators controlled by the control valves in the third section group.

[0172] The present invention is not limited to the embodiments described above, and it goes without saying that modifications can be made as appropriate within the scope of the gist of the present invention.

[0173] 1: Work machine 2: Machine body 3a: Work device (dozer device) 3b: Work device (shovel device) 5: Control device 6: Hydraulic system 8: Connecting attachment 9: Work attachment 22: Operating unit 25: Mode selector switch 26: Monitor (notification device / operation input unit) 30a: Lifting hydraulic actuator (first hydraulic actuator: lifting cylinder) 30b: Hydraulic actuator (first hydraulic actuator: boom cylinder) 31b: Hydraulic actuator (first hydraulic actuator: arm cylinder) 32b: Hydraulic actuator (first hydraulic actuator: work tool cylinder) 32a: Dozer blade (blade) 34b: Boom 35b: Arm 36b: Attachment mounting section 60D: Control valve (lifting cylinder control valve) 60L: First AUX sub-control valve (control valve: first hydraulic source) 60F : First AUX main control valve (control valve: second hydraulic power source) 61: Hydraulic fluid outlet port (first AUX port (AUX port)) 63: On / off valve 64: Control valve for connection 80: Hydraulic actuator for connection 90: First hydraulic actuator (hydraulic actuator) CV: Control valve unit L6: First oil passage L8a: AUX sub-oil passage (oil passage: first oil passage) L8: AUX main oil passage (oil passage: second oil passage) L15: Branch oil passage

Claims

1. A work machine having an attachment mounting portion to which a connecting attachment can be attached, which includes a connecting hydraulic actuator that can be switched between a connected state in which a work attachment is connected and a disconnected state in which the connection of the work attachment is released, the work machine comprising: a control valve for controlling the supply and discharge of hydraulic fluid; a first oil passage connecting the control valve and a first hydraulic actuator; a branch oil passage branching from the first oil passage and connectable to the connecting hydraulic actuator; an on-off valve provided on the first hydraulic actuator side of the branching portion of the first oil passage with the branch oil passage and for opening and closing the first oil passage; and a connecting control valve for opening and closing the branch oil passage, the work machine being switchable between a first state in which the on-off valve is in an open state and the connecting control valve is in a closed state and hydraulic fluid from the control valve is supplied to the first hydraulic actuator, and a second state in which the on-off valve is in a closed state and the connecting control valve is in an open state and hydraulic fluid from the control valve is supplied to the connecting hydraulic actuator.

2. The work machine according to claim 1, wherein the connecting hydraulic actuator can release the connection of the work attachment when hydraulic fluid is supplied from the control valve, and maintains the connection of the work attachment when hydraulic fluid is not supplied from the control valve.

3. The work machine according to claim 1, further comprising: a coupling operation switch for performing a switching operation between the first state and the second state; and a control device for controlling the operation of the on-off valve and the coupling control valve in response to an operation on the coupling operation switch.

4. The work machine according to claim 3, wherein the on-off valve and the connecting control valve are operated in response to an operation on the connecting operation switch when the operating state of the first hydraulic actuator or the equipment driven by the first hydraulic actuator is in a predetermined state, and the on-off valve and the connecting control valve are not operated even if the connecting operation switch is operated when the operating state is not the predetermined state.

5. The work machine according to claim 1, further comprising an operating unit for operating the control valve to change the flow rate of hydraulic fluid supplied from the control valve, wherein in the first state the operating unit operates the first hydraulic actuator, and in the second state the operating unit operates the connecting hydraulic actuator.

6. The work machine according to claim 1, comprising a machine body, a lifting arm attached to the machine body, a dozer blade attached to the tip of the lifting arm, and a lifting hydraulic actuator for raising and lowering the lifting arm, wherein the first hydraulic actuator is the lifting hydraulic actuator.

7. The work machine according to claim 1, having a hydraulic fluid outlet port capable of supplying hydraulic fluid to an external hydraulic device equipped with the first hydraulic actuator, wherein the first oil passage is an oil passage connecting the control valve and the hydraulic fluid outlet port.

8. The work machine according to claim 1, comprising a machine body, a working device having a boom rotatably attached to the machine body, and an arm rotatably attached to the boom, wherein the first hydraulic actuator is a hydraulic actuator that drives at least a part of the working device.

9. The work machine according to claim 1, comprising a machine body, a boom rotatably attached to the machine body, and an arm rotatably attached to the boom, wherein the attachment mounting portion is provided on the arm.

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