Work equipment

Abstract

This prevents the work attachment from experiencing insufficient output. [Solution] The work machine includes an attachment mounting section to which a work attachment 9 including a hydraulic actuator is detachably mounted, a hydraulic fluid outlet port 61 to which a hydraulic fluid supply passage for supplying hydraulic fluid to the hydraulic actuator can be connected, a first hydraulic power source 60L and a second hydraulic power source 60F capable of supplying hydraulic fluid to the hydraulic fluid outlet port 61, a second oil passage L8 connecting the second hydraulic power source 60F and the hydraulic fluid outlet port 61, and the first hydraulic power source 60L and the hydraulic fluid outlet The system includes a first oil passage L8a connecting to the outlet port 61 or the second oil passage L8, and is switchable between a first mode that allows the supply of hydraulic fluid from the second hydraulic source 60F to the hydraulic fluid outlet port 61 and blocks the supply of hydraulic fluid from the first hydraulic source 60L to the hydraulic fluid outlet port 61, and a second mode that allows the supply of hydraulic fluid from the second hydraulic source 60F to the hydraulic fluid outlet port 61 and from the first hydraulic source 60L to the hydraulic fluid outlet port 61.

Description

Technical Field

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[0001] The present invention relates to a working machine having an AUX port capable of supplying hydraulic oil to a hydraulic actuator of a working attachment.

Background Art

[0002] Conventionally, some working machines such as backhoes have an AUX (Auxiliary) port for supplying hydraulic oil to an actuator (hydraulic actuator) equipped on a working attachment that can be detachably (replaceably) attached (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the required amount of hydraulic oil varies depending on the working attachment (actuator), and the discharge amount of hydraulic oil from a normal AUX port may result in insufficient output.

[0005] Therefore, the present invention provides a working machine capable of suppressing the working attachment from having insufficient output.

Means for Solving the Problems

[0006] The work machine of the present invention includes an attachment mounting section to which a work attachment including a hydraulic actuator is detachably mounted; a hydraulic oil outlet port to which a hydraulic oil supply passage for supplying hydraulic oil to the hydraulic actuator can be connected; a first hydraulic power source and a second hydraulic power source capable of supplying hydraulic oil to the hydraulic oil outlet port; a second oil passage connecting the second hydraulic power source and the hydraulic oil outlet port; and a first oil passage connecting the first hydraulic power source and the hydraulic oil outlet port or the second oil passage. The machine is switchable between a first mode that allows the supply of hydraulic oil from the second hydraulic power source to the hydraulic oil outlet port and blocks the supply of hydraulic oil from the first hydraulic power source to the hydraulic oil outlet port, and a second mode that allows the supply of hydraulic oil from the second hydraulic power source to the hydraulic oil outlet port and the supply of hydraulic oil from the first hydraulic power source to the hydraulic oil outlet port. [Effects of the Invention]

[0007] According to the present invention, it is possible to prevent the work attachment from experiencing insufficient output. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view from the front of a work machine according to one embodiment of the present invention. [Figure 2] Figure 2 is an exploded perspective view of the work machine according to the same embodiment, seen from the front. [Figure 3] Figure 3 is a schematic side view of the attachment mounting section of the work machine according to the same embodiment and the bucket, which is a work attachment. [Figure 4] Figure 4 is a schematic side view of the attachment mounting section of the work machine and the breaker, which is a work attachment, according to the same embodiment. [Figure 5] Figure 5 is a schematic diagram illustrating the hydraulic system of the work machine according to the same embodiment. [Figure 6] Figure 6 is a block diagram of the control device for the work machine according to the same embodiment. [Figure 7] Figure 7 is a schematic block diagram of the control valve unit in the hydraulic system of the work machine according to the same embodiment. [Modes for carrying out the invention]

[0009] (1-1. Overall Structure) 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, 4, a machine body 2 rotatably supported on the traveling devices 4, and work devices 3a, 3b supported on 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 (a left operating lever 22a for rotating the turntable 21, a right operating lever 22b for operating the shovel device 3b, which is the work device 3b and will be described later, a dozer operating lever 22c for operating the dozer device 3a, which is the work device 3a and will be described later), 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, which will be described later, 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), a travel lever 22d, operating switches 23, 24, 25, a control device 5, and an operator's seat protection device 27 that protects the operator's seat DS (operator).

[0014] The left control lever 22a and the right control lever 22b can be tilted forward, backward, left, and right. The left control lever 22a controls the rotation of the machine body 2 (turntable 21) according to the direction and amount of tilt, and the right control lever 22b controls the operation of the work device 3b according to the direction and amount of tilt. The dozer control lever 22c can swing back and forth and controls the raising and lowering of the work device (dozer device) 3a according to the swing position. A pair of travel levers 22d are provided corresponding to the left and right travel devices 4, and swinging them back and forth controls the forward and reverse (reverse) movement of the travel devices 4.

[0015] 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 7).

[0016] In this embodiment, the first operation switch 23 is located above the right operation lever 22b, the second operation switch 24 is located above the left operation lever 22a, and the mode selector switch 25 is located on the control panel, each of which is operated by the operator with their fingers. In this embodiment, the mode selector 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.

[0017] The working device 3b includes an attachment mounting portion 36b to which the working attachment 9 is detachably mounted. Specifically, the other working device 3b includes a boom 34b that is rotatable (swingable) about a vertical axis with respect to the turntable 21 and is connected so as to be rotatable about a first horizontal axis S1, an arm 35b that is connected to the tip of the boom 34b so as to be rotatable about a second horizontal axis S2, and a working attachment 9 that is detachably attached to an attachment mounting portion 36b provided at the tip of the arm 35b. As the working attachment 9, for example, a bucket (see FIGS. 1, 2, and 3), a hydraulic crusher, a hydraulic breaker (see FIG. 4), an angle boom, an earth auger, a pallet fork, a sweeper, a mower, a snow blower, etc. can be attached. Note that, as shown in FIG. 4, some of the working attachments 9 include a hydraulic actuator (hereinafter, the hydraulic actuator of the working attachment 9 is referred to as a second hydraulic actuator) 90.

[0018] FIG. 3 is a schematic side view showing an example when a bucket is mounted as the working attachment 9, and FIG. 4 is a schematic side view showing an example when a breaker is mounted as the working attachment 9. As shown in FIGS. 3 and 4, the attachment mounting portion 36b includes a first link body 360 that connects the rod end of a working tool cylinder 32b, which will be described later, and the arm 35b, and a second link body 361 that connects the rod end of the working tool cylinder 32b and a connecting portion 91 of the working attachment 9.

[0019] Further, as shown in FIG. 5, the work machine 1 includes left and right traveling motors M1 that drive the traveling device 4, a turning motor M2 that turns 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 implement 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 includes a hydraulic system 6 that can supply hydraulic oil to each of the hydraulic actuators M1, M2, 30a,....

[0020] As shown in FIG. 6, the control device 5 includes 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 to which input signals (electrical signals) are input from the operation unit 22, each operation switch 23, 24, 25, and various sensors provided in the work machine 1, and an output unit 53 that outputs control signals to each part to be controlled. The control device 5 generates a control signal for controlling each part of the work machine 1 based on the input signal input from the input unit 52 and the information stored in the storage unit 51, and outputs it to each part to be controlled.

[0021] 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 the present embodiment, the storage unit 51 includes a first storage unit 510 that temporarily or short-term stores information used in the processing by the arithmetic control unit 50 (arithmetic unit 500 and control unit 501), and a second storage unit 511 that stores information used in the processing by the arithmetic control unit 50 (arithmetic unit 500 and control unit 501) in a long-term manner. 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 SSD (Solid State Drive).

[0022] (1-2. Hydraulic System 6) As shown in Figure 5, 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 multiple hydraulic pumps P1, P2, P3, P4 that discharge hydraulic fluid and control valves 60A to 60L. Furthermore, as shown in Figures 5 and 7, 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 7). 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 5). 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.

[0023] 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.

[0024] As shown in Figure 7, the control valve unit CV is formed by stacking multiple control valves 60A to 60L that constitute multiple hydraulic power sources.

[0025] 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, etc. 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 one side of the neutral position, and a second position 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 5) without passing through the hydraulic actuators M1, M2, 30a, etc. When the spool is in the first position, hydraulic fluid is discharged from one of the pair of supply / 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 / 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 / discharge ports Eb, and the hydraulic fluid returning from the hydraulic actuators M1, M2, 30a... is received from the other supply / discharge port Eb and discharged into the hydraulic fluid tank T.

[0026] 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 response to 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 response to 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.

[0027] 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.

[0028] 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.

[0029] 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, etc.

[0030] 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 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.

[0031] 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 the second control valve 60F, and a second hydraulic pump P2 that supplies hydraulic fluid to the second section group. In the hydraulic system 6, if multiple of the control valves 60H, 60G, 60F in the second section group are operated simultaneously, priority is given to the discharge of hydraulic fluid from control valves 60H, 60G other than the second control valve (first AUX main control valve described later) 60F. 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 then 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.

[0032] 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 both control valves connected in series and control valves connected in parallel.

[0033] 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, swing motor control valve 60E for controlling the swing 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.

[0034] As described above, the first hydraulic power 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 power 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 power 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 power source.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] The AUX sub-oil passage L8a consists 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.

[0040] 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; for example, they may 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] Note that 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.

[0046] (1-3. Switching the 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 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 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 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 also permitted.

[0047] Let me explain in more detail. As mentioned above, the work machine 1 is equipped with a mode selector switch 25 and a first operation switch 23.

[0048] The mode selector 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 selector switch 25, it is possible to easily switch between the second mode, which can supply a high flow rate of hydraulic fluid to the second hydraulic actuator 90, and the first mode, which can supply a smaller amount of hydraulic fluid than the second mode, by operating the switch.

[0049] 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.

[0050] 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.

[0051] On the other hand, when the mode selector 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 operation 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.

[0052] 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 operating switch 23.

[0053] 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 hydraulic fluid from the first hydraulic pump P1 to the third hydraulic pump P3 merges and is 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.

[0054] (1-4. 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.

[0055] (Item 1) A work machine 1 includes an attachment mounting section 36b to which a work attachment 9 including a hydraulic actuator 90 is detachably mounted, 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, a first hydraulic power source and a second hydraulic power source capable of supplying hydraulic fluid to the hydraulic fluid outlet port 61, a second oil passage L8 connecting the second hydraulic power source and the hydraulic fluid outlet port 61, and a first oil passage L8a connecting the first hydraulic power source and the hydraulic fluid outlet port 61 or the second oil passage L8, and is switchable between a first mode that allows the supply of hydraulic fluid from the second hydraulic power source to the hydraulic fluid outlet port 61 and blocks the supply of hydraulic fluid from the first hydraulic power source to the hydraulic fluid outlet port 61, and a second mode that allows the supply of hydraulic fluid from the second hydraulic power source to the hydraulic fluid outlet port 61 and the supply of hydraulic fluid from the first hydraulic power source to the hydraulic fluid outlet port 61.

[0056] According to the work machine 1 of item 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.

[0057] As a result, during operation in the second mode, a larger amount of hydraulic fluid can be supplied to the hydraulic fluid outlet port 61 than during operation in the first mode. Therefore, according to the work machine 1 of item 1, it is possible to prevent the work attachment 9 from experiencing insufficient output.

[0058] (Item 2) The work machine 1 according to item 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.

[0059] According to the work machine 1 of item 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.

[0060] (Item 3) The work machine 1 according to item 2, further 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.

[0061] According to the work machine 1 of item 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.

[0062] (Item 4) The work machine 1 according to any one of items 1 to 3, which is equipped with a mode switching switch 25 for the operator to switch between the first mode and the second mode.

[0063] According to the work machine 1 in item 4, the operator can switch between the first mode and the second mode by operating the mode switching switch 25 based on their own will.

[0064] (Item 5) The first hydraulic power 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 power 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 2 to 4, which is subordinate to item 2.

[0065] According to the work machine 1 of item 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 influence of the drive of the work attachment 9 on the operation of other hydraulic actuators.

[0066] (Item 6) The work machine 1 according to item 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.

[0067] According to the work machine 1 of item 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.

[0068] (Item 7) A work machine 1 according to item 5 or item 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.

[0069] According to the work machine 1 of item 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.

[0070] (Item 8) The work machine according to item 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.

[0071] According to the work equipment of item 8, 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. [Explanation of Symbols]

[0072] 1: Work machine 5: Control device 6: Hydraulic System 9: Work attachments 11: Oil road 23: Operation switch (1st operation switch: mode selector switch) 36b: Attachment mounting section 60L: 1st AUX sub-control valve (control valve: 1st hydraulic power source) 60F: 1st AUX main control valve (control valve: 2nd hydraulic power source) 61: First AUX port (hydraulic fluid outlet port) 90: Second hydraulic actuator (hydraulic actuator) CV: Control Valve Unit L8a: AUX sub oilway (oilway: 1st oilway) L8:AUX main oil path (oil path: 2nd oil path)

Claims

1. An attachment mounting section on which a work attachment including a hydraulic actuator is detachably attached, A hydraulic fluid outlet port to which a hydraulic fluid supply path for supplying hydraulic fluid to the hydraulic actuator can be connected, A first hydraulic power source and a second hydraulic power source capable of supplying hydraulic fluid to the hydraulic fluid outlet port, A second oil passage connecting the second hydraulic power source and the hydraulic fluid outlet port, The first hydraulic source and the first oil passage connecting the hydraulic fluid outlet or the second oil passage are included, A work machine that can switch between a first mode, which allows the supply of hydraulic fluid from the second hydraulic source to the hydraulic fluid outlet port and shuts off the supply of hydraulic fluid from the first hydraulic source to the hydraulic fluid outlet port, and a second mode, which allows the supply of hydraulic fluid from the second hydraulic source to the hydraulic fluid outlet port and the supply of hydraulic fluid from the first hydraulic source to the hydraulic fluid outlet port.

2. The first hydraulic power source includes a first hydraulic pump and a first control valve that controls the supply and discharge of hydraulic fluid from the first hydraulic pump to the first oil passage. The second hydraulic power source includes a second hydraulic pump and a second control valve that controls the supply and discharge of hydraulic fluid from the second hydraulic pump to the second oil passage. The work machine according to claim 1, wherein in the first mode, the supply of hydraulic fluid from the first hydraulic pump to the hydraulic fluid outlet port is shut off by the first control valve.

3. The system includes an oil flow rate control switch for the operator to control the flow rate of hydraulic fluid supplied from the hydraulic fluid outlet port to the hydraulic actuator. In the first mode, the operation of the second control valve is controlled in accordance with the operation of the oil volume control switch, thereby controlling the flow rate of hydraulic fluid supplied from the hydraulic fluid outlet port to the hydraulic actuator. The work machine according to claim 2, wherein in the second mode, the operation of the first control valve and the second control valve is controlled in accordance with the operation of the oil volume control switch, thereby controlling the flow rate of hydraulic fluid supplied from the hydraulic fluid outlet port to the hydraulic actuator.

4. The work machine according to claim 1, further comprising a mode switching switch for the operator to perform the operation of switching between the first mode and the second mode.

5. The first hydraulic power source includes a first section group having a plurality of control valves that control the supply and discharge of hydraulic fluid to different hydraulic actuators, and is configured such that if multiple of the control valves in the first section group are operated simultaneously, the discharge of hydraulic fluid from control valves other than the first control valve is given priority. The work machine according to claim 2, wherein the second hydraulic source includes a second section group having a plurality of control valves that control the supply and discharge of hydraulic fluid to different hydraulic actuators, and is configured such that if a plurality of the control valves in the second section group are operated simultaneously, the discharge of hydraulic fluid from control valves other than the second control valves is given priority.

6. The control valve unit comprises the first section group and the second section group, The work machine according to claim 5, wherein the first oil passage is provided outside the control valve unit.

7. A third hydraulic source includes a third section group having a plurality of control valves that control the supply and discharge of hydraulic fluid to different hydraulic actuators, and a third hydraulic pump that supplies hydraulic fluid to the third section group. The work machine according to claim 5, wherein the hydraulic fluid that has passed through the third section group is supplied to the upstream side of the second control valve, and the hydraulic fluid from the second hydraulic pump and the hydraulic fluid from the third hydraulic pump merge in the control valve unit and are supplied from the second control valve to the hydraulic fluid outlet port.

8. The work machine according to claim 7, wherein when the control valve in the third section group is operated, the discharge of hydraulic fluid from the control valve takes precedence over the hydraulic fluid supplied from the third section to the second control valve.

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