Work machine

Abstract

To reduce damage to hydraulic hoses caused by bending of the hydraulic hoses extending from a first boom to a third boom, and to reduce number of parts and required costs.SOLUTION: A work machine includes a first boom supported on a machine body so as to be rotatable in the vertical direction, a second boom supported so as to be rotatable in the left-right direction relative to the first boom, a third boom supported so as to be rotatable in the left-right direction relative to the second boom, and a hydraulic hose extending along a back surface of the first boom. The first boom has an opening on a back surface. The hydraulic hose passes through an opening from the outside to the inside of the first boom and extends through the inside of the second boom toward the third boom.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a work machine such as a hydraulic excavator. [Background technology]

[0002] For example, Patent Document 1 discloses an example of a method for routing hydraulic hoses in a work machine. In the work machine of Patent Document 1, a second boom is swingably pivoted to a first boom that is swingably pivoted to the machine body. A third boom is swingably pivoted to the second boom. A hose cover is attached to the side of the second boom. The hydraulic hose that enters the inside of the first boom from the outside of the first boom is pulled out to the side of the second boom and extends toward the third boom by passing between the side of the second boom and the hose cover. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-048524 Summary of the Invention [Problem to be solved by the invention]

[0004] In the hydraulic hose routing of Patent Document 1, for example, when the second boom is rotated to the left, tension is generated in the hydraulic hose, which may cause the hydraulic hose to come into contact with and rub against surrounding components (e.g., the rotation shaft of the second boom). Therefore, the length of the hydraulic hose must be set to avoid this tension. However, with this length setting, the hydraulic hose is more likely to bend when the second boom is rotated to the right, which may result in the hydraulic hose coming into contact with the hose cover and being damaged. In particular, the hydraulic hose extending from the first boom beyond the second boom toward the third boom is longer than other hydraulic hoses that do not extend beyond the second boom (e.g., the hydraulic hose extending toward the offset cylinder located to the side of the second boom), and is therefore more likely to move uncontrollably when the second boom is rotated. Therefore, there is an increased risk that the hydraulic hose will come into contact with surrounding components and be damaged when the hydraulic hose is bent. Furthermore, a configuration in which a cover member such as a hose cover is attached to the work machine increases the number of parts and the required costs.

[0005] The present invention has been made to solve the above problems, and its object is to provide a work machine that can reduce damage to the hydraulic hoses that are caused by bending of the hydraulic hoses extending from the first boom to the third boom, and that can reduce the number of parts and the required costs. [Means for solving the problem]

[0006] A work machine according to one aspect of the present invention is a work machine comprising a first boom supported so as to be rotatable in the vertical direction relative to a body, a second boom supported so as to be rotatable in the left-right direction relative to the first boom, a third boom supported so as to be rotatable in the left-right direction relative to the second boom, and a hydraulic hose extending along the back surface of the first boom, wherein the first boom has an opening on the back surface, and the hydraulic hose passes through the opening to enter the inside of the first boom from the outside, and extends through the inside of the second boom towards the third boom. [Effects of the Invention]

[0007] According to the above configuration, it is possible to reduce damage to the hydraulic hoses that are caused by bending of the hydraulic hoses extending from the first boom to the third boom, and it is also possible to reduce the number of parts and the required costs. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a left side view showing a schematic configuration of a hydraulic excavator, which is an example of a work machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a right side view of the hydraulic excavator. [Figure 3] FIG. 2 is an enlarged perspective view showing a boom of a work machine provided in the hydraulic excavator. [Figure 4] FIG. 2 is an enlarged right side view of the boom and arm of the work machine. [Figure 5] FIG. 2 is a right side view showing the boom and the arm with a portion of the boom not shown. [Figure 6] FIG. 2 is a perspective view of the first boom and second boom of the work machine in a connected state. [Figure 7] FIG. 2 is an exploded perspective view of the first boom and the second boom. [Figure 8] FIG. 2 is a perspective view of the second boom and third boom of the work machine in a connected state. [Figure 9] FIG. 2 is an exploded perspective view of the second boom and the third boom. [Figure 10] FIG. 2 is a perspective view showing hydraulic hoses routed in a state in which the first boom and the second boom are rotatably connected. [Figure 11] FIG. 4 is a plan view of the second boom and the offset cylinder. [Figure 12] FIG. 4 is a perspective view of the second boom and the offset cylinder. [Figure 13] FIG. 2 is a perspective view of a second boom base end portion of the second boom. [Figure 14] FIG. 4 is a perspective view showing the configuration of a fixing part fixed to the base end of the second boom. [Figure 15]FIG. 2 is a perspective view of the second boom before a tube is inserted therein. [Figure 16] FIG. 10 is a perspective view of the second boom after the tube has been inserted therein. [Figure 17] FIG. 10 is a perspective view of the second boom after the fixing part has been fixed to the base end of the second boom. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes an embodiment of the present invention with reference to the drawings.

[0010] [1. Construction Machine Configuration] 1 and 2 are left and right side views, respectively, showing the general configuration of a hydraulic excavator 1, which is an example of a work machine according to this embodiment. The hydraulic excavator 1 includes a lower traveling structure 2, a work implement 3, and an upper rotating structure 4. Note that the upper rotating structure 4 may hereinafter also be referred to as the "machine body."

[0011] For ease of explanation, directions are defined as follows. The direction in which the operator (operator, driver) seated in the driver's seat 41a inside the control section 41 of the upper rotating body 4 faces is defined as the forward direction, and the opposite direction is defined as the rearward direction. Therefore, when the upper rotating body 4 is not rotating relative to the lower running body 2 (swing angle 0°), the fore-and-aft direction of the upper rotating body 4 coincides with the direction in which the lower running body 2 moves forward and backward. Also, the left side as seen from the operator seated in the driver's seat 41a is defined as the "left," and the right side is defined as the "right." Furthermore, the direction of gravity, which is perpendicular to the fore-and-aft direction and the left-and-right direction, is defined as the up-and-down direction, with the upstream side of the direction of gravity defined as the "up" and the downstream side defined as the "down." In the drawings, the hydraulic excavator 1 is shown in a state in which the upper rotating body 4 is not rotating relative to the lower running body 2. In addition, in the drawings, where necessary, the following symbols are used to indicate front: "F", rear: "B", right: "R", left: "L", top: "U", and bottom: "D".

[0012] The lower traveling body 2 is driven by power from an engine 40 (see FIG. 1 ) and causes the hydraulic excavator 1 to travel. The lower traveling body 2 is equipped with a pair of left and right crawlers 21 and a pair of left and right traveling motors 22. Each traveling motor 22 is a hydraulic motor. The left and right traveling motors 22 drive the left and right crawlers 21, respectively, thereby moving the hydraulic excavator 1 forward and backward. The lower traveling body 2 is provided with a blade 23 for performing ground leveling work. The blade 23 rotates up and down by extension and retraction of a blade cylinder (not shown).

[0013] The work machine 3 is driven by power from the engine 40 and performs excavation work to dig up earth and sand, etc. The work machine 3 is mounted on a revolving frame 42 of the upper revolving body 4. The work machine 3 comprises, in order from the side connected to the upper revolving body 4, a boom 31, an arm 32, and a bucket 33. Excavation work can be performed by independently driving the boom 31, the arm 32, and the bucket 33.

[0014] The boom 31 has, in order from the connection side with the upper rotating body 4, a first boom 31A, a second boom 31B, and a third boom 31C.

[0015] For the sake of convenience in the following explanation, the base end and tip end of each member are defined as follows: In the connection direction from the upper rotating body 4 to the boom 31, arm 32, and bucket 33, of both ends of each member, the end connected closer to the upper rotating body 4 is defined as the base end, and the end connected farther from the upper rotating body 4 is defined as the tip end. The above-mentioned members include the boom 31, arm 32, and bucket 33, as well as the first boom 31A, second boom 31B, and third boom 31C that constitute the boom 31.

[0016] The first boom 31A is driven by a boom cylinder 31s (see FIG. 2). The boom cylinder 31s is located forward of the first boom 31A. The base end of the first boom 31A and one end of the boom cylinder 31s are rotatably supported on the revolving frame 42 of the upper revolving body 4. The first boom 31A is bent at an obtuse angle midway from the base end to the tip end. The other end of the boom cylinder 31s is connected to the bent portion of the first boom 31A that is bent at an obtuse angle. The extension and contraction of the boom cylinder 31s causes the first boom 31A to rotate vertically relative to the revolving frame 42. In this way, the hydraulic excavator 1 is provided with the first boom 31A that is supported rotatably in the vertical direction relative to the machine body.

[0017] The base end of the second boom 31B is supported on the tip end of the first boom 31A so as to be rotatable in the left-right direction. One end of an offset cylinder 31f is connected to the left side of the second boom 31B via an offset cylinder support part 313 (see FIG. 11), which will be described later. The other end of the offset cylinder 31f is connected to the third boom 31C. Furthermore, one end of a link rod 31r is connected to the tip end of the first boom 31A. The other end of the link rod 31r is connected to the third boom 31C.

[0018] The third boom 31C is supported on the tip of the second boom 31B so as to be rotatable in the left-right direction. By extending and contracting the offset cylinder 31f, the second boom 31B rotates left-right relative to the first boom 31A, and the third boom 31C rotates left-right relative to the second boom 31B. This allows the third boom to move in parallel (offset) in the left-right direction relative to the first boom 31A.

[0019] As described above, the hydraulic excavator 1 includes the second boom 31B supported so as to be rotatable in the left-right direction relative to the first boom 31A, and the third boom 31C supported so as to be rotatable in the left-right direction relative to the second boom 31B.

[0020] The base end of the arm 32 is rotatably supported by the third boom 31C. One end of the arm cylinder 32a is connected to the base end of the arm 32. The middle part of the arm cylinder 32a is connected to the third boom 31C. The middle part is located between one end and the other end of the arm cylinder 32a. As the arm cylinder 32a extends and retracts, the arm 32 rotates up and down relative to the third boom 31C. In this way, the hydraulic excavator 1 is provided with the arm 32 that is supported up and down rotatably relative to the third boom 31C.

[0021] A bucket 33 is rotatably connected to the tip end of the arm 32. The bucket 33 is also connected to a link mechanism 34. One end of a bucket cylinder 33a is connected to the base end of the arm 32. The other end of the bucket cylinder 33a is connected to the link mechanism 34. The bucket 33 rotates up and down relative to the arm 32 as the bucket cylinder 33a extends and retracts.

[0022] The boom cylinder 31s, the offset cylinder 31f, the arm cylinder 32a, and the bucket cylinder 33a are configured by hydraulic cylinders.

[0023] The upper rotating body 4 is configured to be able to rotate relative to the lower running body 2 via a rotation bearing (not shown). A control unit 41, a rotation frame 42, a rotation motor 43, a machine room 44, a canopy 45, etc. are arranged on the upper rotating body 4. The control unit 41 and the machine room 44 are arranged on the rotation frame 42. The canopy 45 is erected on the floor of the control unit 41 and covers the top of the control unit 41.

[0024] The upper rotating body 4 rotates via a rotation bearing driven by a rotation motor 43, which is a hydraulic motor. Inside the machine room 44, in addition to the engine 40 that provides power to each part, multiple hydraulic pumps (not shown) are arranged.

[0025] Each hydraulic pump supplies hydraulic oil (pressurized oil) to a hydraulic motor (for example, the left and right travel motors 22, the swing motor 43) and a hydraulic cylinder (for example, the boom cylinder 31s, the offset cylinder 31f, the arm cylinder 32a, and the bucket cylinder 33a). The hydraulic motors and hydraulic cylinders that are driven by the supply of hydraulic oil from any hydraulic pump are collectively called hydraulic actuators.

[0026] A driver's seat 41a is arranged in the control section 41 where the operator sits. An operating section 41b is arranged around the driver's seat 41a. The operating section 41b is composed of an operating lever, a switch, a button, etc. for driving the hydraulic actuator. The operator sits in the driver's seat 41a and operates the operating section 41b to drive the hydraulic actuator. This allows the lower traveling body 2 to travel, the blade 23 to perform ground leveling work, the work implement 3 to perform excavation work, the upper rotating body 4 to rotate, etc.

[0027] [2. Hydraulic hose routing] Hydraulic oil is supplied to each hydraulic cylinder of the work equipment 3 via hydraulic hoses. The hydraulic hoses are connected to a control valve (not shown) in the machine room 44. The control valve is a directional switching valve that controls the flow direction and amount of hydraulic oil supplied from the hydraulic pump to each hydraulic cylinder in response to operation of the operating unit 41b. Common methods such as pilot type, electromagnetic type, and mechanical type are used to control the control valve. Each hydraulic cylinder of the work equipment 3 is, for example, a double-acting cylinder. For this reason, two hydraulic hoses H are provided corresponding to each hydraulic cylinder.

[0028] Of the multiple hydraulic hoses extending from the control valve to each hydraulic cylinder of the work implement 3, the hydraulic hose connected to the boom cylinder 31s crosses the base end of the first boom 31A, is pulled out in front of the first boom 31A, and is connected to the boom cylinder 31s. The remaining hydraulic hoses pass along the back side of the first boom 31A and extend toward each hydraulic cylinder. Below, the routing of the hydraulic hoses connected to hydraulic cylinders other than the boom cylinder 31s will be described in detail. Note that below, the hydraulic hoses connected to hydraulic cylinders other than the boom cylinder 31s will be referred to as hydraulic hoses H.

[0029] FIG. 3 is an enlarged perspective view showing the boom 31 of the work implement 3. The hydraulic hose H connected to the control valve extends upward along the back surface 31A-b of the first boom 31A. Here, the back surface 31A-b of the first boom 31A refers to the surface located on the rear side when viewing the first boom 31A from the front side. Openings 31A-P are provided in the back surface 31A-b. Each hydraulic hose H passes from the outside of the first boom 31A through the openings 31A-P to enter the interior of the first boom 31A. In this way, the hydraulic excavator 1 is equipped with hydraulic hoses H extending along the back surface 31A-b of the first boom 31A. The first boom 31A has openings 31A-P in the back surface 31A-b.

[0030] In FIG. 3, the symbol E denotes a wire harness, which is to be distinguished from the hydraulic hose H. The wire harness E is made by bundling electric wires used for power supply and signal communication in a corrugated tube. One end of the wire harness E is connected to electrical components (including a power source such as a lead battery) in the machinery room 44 (see FIG. 1), and the other end is connected to a socket Es located on the side of the third boom 31C. The wire harness E extends from the machinery room 44 side along the back surface 31A-b of the first boom 31A, passes outside the second boom 31B without entering the opening 31A-P, and extends to the third boom 31C. In addition, the wire harness E, like the hydraulic hose H, may be routed through the opening 31A-P provided in the back surface 31A-b of the first boom 31A.

[0031] 2, a branch harness E1 branched from the wire harness E is connected to a headlamp HL attached to the first boom 31A. The headlamp HL is turned on by supplying power to the headlamp HL via the branch harness E1.

[0032] 4 and 5 are enlarged right side views showing the boom 31 and arm 32 of the work implement 3. However, for convenience, part of the boom 31 shown in FIG. 4 (the tip of the first boom 31A, the right wall of the second boom 31B, and the third boom 31C) is not shown in FIG. 5. The hydraulic hose H, which is led from the outside to the inside of the first boom 31A through the opening 31A-P shown in FIG. 3, is led into the inside of the second boom 31B as shown in FIGS. 4 and 5. The hydraulic hose H then passes through the inside of the second boom 31B and is led into the inside of the third boom 31C. Inside the third boom 31C, the corresponding hydraulic hoses H extend toward the arm cylinder 32a and the bucket cylinder 33a, respectively.

[0033] As described above, the (plurality of) hydraulic hoses H pass through the openings 31A-P from the outside to the inside of the first boom 31A, pass through the inside of the second boom 31B and extend toward the third boom 31C. This provides the following effects.

[0034] Because the hydraulic hose H passes through the opening 31A-P in the back surface 31A-b of the first boom 31A and enters the interior of the second boom 31B, the hydraulic hose H can be routed inside the second boom 31B so as to pass near the center of the second boom 31B in the left-right direction. This makes it possible to route the hydraulic hose H to a minimum length that minimizes tension and deflection, regardless of whether the second boom 31B is rotated left or right (whether the third boom 31C is offset left or right). Therefore, it is possible to reduce the movement of the hydraulic hose H when the second boom 31B is rotated, compared to a conventional configuration (a configuration in which the hydraulic hose is pulled out to the side of the second boom). As a result, it is possible to reduce the risk of the hydraulic hose H moving wildly and coming into contact with surrounding components, resulting in damage.

[0035] In particular, the hydraulic hose H extending from the first boom 31A, over the second boom 31B, toward the third boom 31C is longer than other hydraulic hoses that do not extend beyond the second boom 31B (for example, the second hydraulic hose H2 (see FIG. 11) extending toward the offset cylinder 31f arranged to the side of the second boom 31B), and the hydraulic hose H is prone to movement when the second boom 31B rotates. For this reason, from the perspective of reducing damage to the hydraulic hose H extending from the first boom 31A toward the third boom 31C, the configuration of this embodiment in which the hydraulic hose H passes through the opening 31A-P of the first boom 31A and enters the interior of the second boom 31B is extremely effective.

[0036] Furthermore, because the hydraulic hose H passes through the inside of the second boom 31B, there is no need to attach a cover member to the side of the second boom 31B as in the past to protect the hydraulic hose H. This reduces the number of parts and reduces the required costs.

[0037] As shown in Figure 5, the arm 32 of the work implement 3 has a rotation shaft 32X. The rotation shaft 32X extends in the left-right direction and is supported by the third boom 31C (see Figure 4). The hydraulic hose H, which passes through the inside of the second boom 31B and extends toward the arm 32, passes above the rotation shaft 32X of the arm 32.

[0038] With such an arrangement of the hydraulic hose H, the hydraulic hose H is prevented from bending in the vertical direction when the arm 32 rotates in the vertical direction. Therefore, the hydraulic hose H is less likely to come into contact with the surroundings and be damaged when the arm 32 rotates in the vertical direction.

[0039] [3. Details of the boom] Next, a more detailed description will be given of the configuration of the boom 31 that enables the routing of the above-mentioned hydraulic hose H. In the following description, appropriate reference numerals will be used to distinguish between the base end and the tip end of each member.

[0040] Fig. 6 is a perspective view of the first boom 31A and second boom 31B of the work implement 3 in a connected state. Fig. 7 is an exploded perspective view of the first boom 31A and second boom 31B of Fig. 6. The first boom 31A has a first boom main body 31A-m and a first boom tip 31A-t.

[0041] The first boom tip 31A-t is provided at one end of the first boom main body 31A-m. A hose outlet 31A-Q is provided at the first boom tip 31A-t. The hose outlet 31A-Q is provided to guide the hydraulic hose H that has entered the inside of the first boom 31A (particularly the first boom tip 31A-t) through the opening 31A-P to the first space SP1, which will be described later. A first boom base end (not shown) is provided on the opposite side of the first boom main body 31A-m from the first boom tip 31A-t. The first boom base end is supported by the upper revolving body 4 so as to be rotatable in the vertical direction.

[0042] A first rotating shaft insertion portion 311 (see FIG. 7) is provided at the first boom tip portion 31A-t. The first rotating shaft insertion portion 311 has a pair of first insertion portions 311a. Each first insertion portion 311a has a first insertion-side through-hole P1. A first shaft portion 351 is inserted into each first insertion-side through-hole P1. Therefore, the first insertion portions 311a are arranged side by side in the insertion direction of the first shaft portion 351. The first shaft portion 351 is a portion that serves as a rotation axis when the second boom 31B rotates with respect to the first boom 31A. The insertion direction is the axial direction AX1 in which the central axis of the first shaft portion 351 extends. The first insertion portions 311a are arranged side by side in the axial direction AX1 with a gap T1 between them. The gap T1 is provided for disposing a first inserted portion 31B1 of the second boom 31B, which will be described later.

[0043] The two first rotating shaft insertion portions 311 are arranged side by side in the axial direction AX1 and rotatably support the second boom 31B. More specifically, the first rotating shaft insertion portions 311 are arranged side by side in the axial direction AX1 with a first space SP1 interposed therebetween. The first space SP1 is provided as a space for passing the hydraulic hose H. A separate first shaft portion 351 is inserted into each of the first rotating shaft insertion portions 311. In this way, the first boom 31A has first rotating shaft insertion portions 311 into which the individual first shaft portions 351 are inserted and which rotatably support the second boom 31B.

[0044] The second boom 31B has a second boom main body 31B-m, a second boom base end 31B-e, and a second boom tip end 31B-t. The second boom base end 31B-e is provided at one end of the second boom main body 31B-m, i.e., the end on the connection side with the first boom 31A. The second boom tip end 31B-t is provided at the other end of the second boom main body 31B-m, i.e., the end on the connection side with the third boom 31C.

[0045] A first inserted portion 31B1 is provided at the base end 31B-e of the second boom 31B. The first inserted portion 31B1 has a first inserted-side through-hole P2 through which the first shaft 351 is inserted. Two first inserted portions 31B1 are provided side by side in the insertion direction of the first shaft 351, i.e., in the axial direction AX1, corresponding to each of the first rotating shaft insertion portions 311 of the first boom 31A.

[0046] With each first inserted portion 31B1 of the second boom 31B inserted between the two first inserting portions 311a of the corresponding first rotating shaft insertion portion 311, i.e., inserted into the gap T1, the first shaft portion 351 is inserted into the first insertion-side through-hole P1 of each first inserting portion 311a and the first insertion-side through-hole P2 of the first inserted portion 31B1, whereby the second boom 31B is supported relative to the first boom 31A so as to be rotatable in the left-right direction about the first shaft portion 351. At this time, the first shaft portions 351 are arranged side by side in the axial direction AX1 via the first space SP1. In other words, the two first shaft portions 351 are located on opposite sides of each other with respect to the first space SP1. Therefore, the second boom 31B is supported by the first boom 31A in an axial direction AX1 of the first shaft 351 at positions opposite to each other with the first space SP1 interposed therebetween so as to be rotatable about the first shaft 351.

[0047] Each first shaft portion 351 is covered with a flange (not shown) and fixed to the first rotating shaft insertion portion 311. This prevents the first shaft portion 351 from coming off the first rotating shaft insertion portion 311.

[0048] FIG. 8 is a perspective view of the second boom 31B and third boom 31C of the work implement 3 in a connected state. FIG. 9 is an exploded perspective view of the second boom 31B and third boom 31C of FIG. 8. The third boom 31C is provided with a second rotating shaft insertion portion 312. The second rotating shaft insertion portion 312 has a pair of second insertion portions 312a. Each second insertion portion 312a has a second insertion-side through-hole P3. A second shaft portion 352 is inserted into each second insertion-side through-hole P3. Therefore, the second insertion portions 312a are arranged side by side in the insertion direction of the second shaft portion 352. The second shaft portion 352 is a portion that serves as a rotation axis when the third boom 31C rotates relative to the second boom 31B. The insertion direction of the second shaft portion 352 is the axial direction AX2 in which the central axis of the second shaft portion 352 extends, and is parallel to the axial direction AX1. The second insertion portions 312a are arranged side by side in the axial direction AX2 with a gap T2 between them. The gap T2 is provided for the placement of a second inserted portion 31B2 of the second boom 31B, which will be described later.

[0049] The two second rotating shaft insertion portions 312 are arranged side by side in the axial direction AX2 and are rotatably supported by the second boom 31B. More specifically, the second rotating shaft insertion portions 312 are arranged side by side in the axial direction AX2 with the second space SP2 interposed between them. The second space SP2 is provided as a space for passing the hydraulic hose H. A separate second shaft portion 352 is inserted into each second rotating shaft insertion portion 312. In this way, the third boom 31C has second rotating shaft insertion portions 312 through which the individual second shaft portions 352 are inserted and which are rotatably supported by the second boom 31B.

[0050] A second insertion portion 31B2 is provided at the tip end 31B-t of the second boom 31B. The second insertion portion 31B2 has a second insertion-side through-hole P4 through which the second shaft 352 is inserted. The second insertion-side through-holes P4 correspond to the second rotating shaft insertion portions 312 of the third boom 31C, and two of them are provided side by side in the insertion direction of the second shaft 352, i.e., in the axial direction AX2.

[0051] With each second inserted portion 31B2 of the second boom 31B inserted between the two second inserting portions 312a of the corresponding second rotating shaft inserting portion 312, i.e., in the gap T2, the second shaft portion 352 is inserted through the second insertion-side through-hole P3 of each second inserting portion 312a and the second insertion-side through-hole P4 of the second inserted portion 31B2, whereby the third boom 31C is supported relative to the second boom 31B so as to be rotatable in the left-right direction about the second shaft portion 352. At this time, the second shaft portions 352 are arranged side by side in the axial direction AX2 via the second space SP2. In other words, the two second shaft portions 352 are located on opposite sides of each other with respect to the second space SP2. Therefore, the third boom 31C is supported by the second boom 31B rotatably about the second shaft portion 352 at positions opposite to each other in the axial direction AX2 of the second shaft portion 352 with the second space SP2 interposed therebetween.

[0052] Each second shaft portion 352 is covered with a flange (not shown) and fixed to the second rotating shaft insertion portion 312. This prevents the second shaft portion 352 from coming off the second rotating shaft insertion portion 312.

[0053] Figure 10 is a perspective view of the hydraulic hose H routed in a state in which the first boom 31A and the second boom 31B are rotatably connected. As shown in Figures 5 and 10, from the perspective of reliably routing the hydraulic hose H through the interior of the second boom 31B, it is desirable that the hydraulic hose H be routed through the first space SP1 and the second space SP2, as shown in the figures.

[0054] 6 and 7, the first shaft portions 351 are arranged side by side in the axial direction AX1 with the first space SP1 interposed therebetween. Such an arrangement is desirable in that the first space SP1 through which the hydraulic hose H passes can be reliably secured between the two first shaft portions 351 arranged side by side in the axial direction AX1.

[0055] In a configuration in which the second boom 31B is rotatably supported by the first rotating shaft insertion portion 311, from the viewpoint of ensuring the first space SP1 through which the hydraulic hose H passes, it is desirable that the first rotating shaft insertion portions 311 be arranged side by side in the axial direction AX1, with the first space SP1 interposed between them, as shown in Figure 7.

[0056] 9 and 10, the second shaft portions 352 are arranged side by side in the axial direction AX2 with the second space SP2 interposed therebetween. Such an arrangement is desirable in that the second space SP2 through which the hydraulic hose H passes can be reliably secured between the two second shaft portions 352 arranged side by side in the axial direction AX2.

[0057] In a configuration in which the third boom 31C is rotatably supported on the second boom 31B by the second rotating shaft insertion portion 312, from the viewpoint of securing the second space SP2 through which the hydraulic hose H passes, it is desirable that the second rotating shaft insertion portions 312 be arranged side by side in the axial direction AX2, with the second space SP2 interposed between them, as shown in Figure 9.

[0058] 5, a pipe 31H is arranged inside the second boom 31B. The pipe 31H extends inside the second boom 31B from the second boom base end 31B-e to the second boom tip end 31B-t. In other words, the second boom 31B has the pipe 31H extending from the first boom 31A side toward the third boom 31C side.

[0059] The pipe 31H has a cylindrical shape. Therefore, the pipe 31H has a space therein. Hereinafter, the space therein is referred to as a third space SP3. In other words, the second boom 31B has the third space SP3 therein. Both ends of the pipe 31H are in communication with the first space SP1 and the second space SP2, respectively.

[0060] The hydraulic hose H is arranged to pass through the third space SP3. This ensures that the hydraulic hose H is arranged to pass through the inside of the second boom 31B.

[0061] In particular, in a configuration in which the second boom 31B has a pipe 31H therein, the pipe 31H has a third space SP3. In this case, the hydraulic hose H is arranged to pass through the inside of the pipe 31H (third space SP3). With this arrangement, even when the second boom 31B performs an offset operation in which it rotates left and right, the pipe 31H prevents the hydraulic hose H from moving wildly inside the second boom 31B, reducing damage to the hydraulic hose H. Furthermore, when passing the hydraulic hose H inside the second boom 31B, it is sufficient to pass it through the inside of the pipe 31H, making it easy to arrange the hydraulic hose H inside the second boom 31B.

[0062] [4. Configuration around the offset cylinder] 11 and 12 are a plan view and a perspective view, respectively, of the second boom 31B and the offset cylinder 31f. The offset cylinder 31f is disposed on the left side of the second boom 31B, with a gap T3 between it and the left side surface 31B-L. An offset cylinder support portion 313 is integrally provided on the left side surface 31B-L of the second boom 31B (particularly the second boom base end portion 31B-e). The offset cylinder support portion 313 protrudes leftward from the left side surface 31B-L and supports the base end portion 31f1 of the offset cylinder 31f. In this way, the hydraulic excavator 1 of this embodiment is equipped with the offset cylinder 31f disposed on the side of the second boom 31B, with a gap T3 between it and the second boom 31B, and the offset cylinder support portion 313 connected to the side surface of the second boom 31B and supporting the offset cylinder 31f.

[0063] FIG. 13 is a perspective view of the second boom base end 31B-e of the second boom 31B to which the offset cylinder support part 313 is connected. The offset cylinder support part 313 has a pair of first support parts 313a. Each of the first support parts 313a has a support-side through-hole 313a1. A third shaft part 353 (see FIG. 12) is inserted into the support-side through-hole 313a1 of each first support part 313a. Therefore, the first support parts 313a are arranged side by side in the insertion direction of the third shaft part 353. The third shaft part 353 is a part that serves as a rotation axis when the offset cylinder 31f extends and retracts and rotates relative to the second boom 31B (particularly the offset cylinder support part 313). The insertion direction of the third shaft part 353 is a direction parallel to the axial direction AX1 of the first shaft part 351.

[0064] The first support portions 313a are arranged side by side and spaced apart in the insertion direction. The spacing between the first support portions 313a in the insertion direction is set according to the thickness of the base end portion 31f1 of the offset cylinder 31f. The base end portion 31f1 of the offset cylinder 31f has a cylinder-side through-hole (not shown) through which the third shaft portion 353 is inserted.

[0065] With the base end 31f1 inserted between the first support portions 313a of the offset cylinder support portion 313, the third shaft portion 353 is inserted through the support-side through-holes 313a1 of the first support portions 313a and the cylinder-side through-hole of the base end portion 31f1. This allows the offset cylinder 31f to rotate left and right about the third shaft portion 353 relative to the second boom 31B when the offset cylinder 31f extends or retracts. The third shaft portion 353 is covered and fixed to the offset cylinder support portion 313 by a flange (not shown). This prevents the third shaft portion 353 from coming off the offset cylinder support portion 313.

[0066] Here, the above-mentioned hydraulic hose H is referred to as the first hydraulic hose H1. That is, the first hydraulic hose H1 is a hydraulic hose that passes through the opening 31A-P of the first boom 31A from the outside to the inside of the first boom 31A, and extends through the inside of the second boom 31B toward the third boom 31C. On the other hand, the hydraulic hose H that passes through the opening 31A-P and the first space SP1 of the first boom 31A and is connected to the offset cylinder 31f is referred to as the second hydraulic hose H2. That is, the hydraulic excavator 1 is equipped with the first hydraulic hose H1 and the second hydraulic hose H2 as hydraulic hoses H.

[0067] As shown in FIGS. 11 and 12 , the second hydraulic hose H2 is arranged through a gap T4. The gap T4 is a space sandwiched between a pair of first support portions 313a and defined between the base end portion 31f1 of the offset cylinder 31f and the left side surface 31B-L of the second boom 31B. With the second hydraulic hose H2 arranged in this manner, the gap T4 between the second boom 31B and the offset cylinder 31f is effectively utilized as routing space for the second hydraulic hose H2. The second hydraulic hose H2 extending to the side of the second boom 31B does not extend to the third boom 31C and is sufficiently short compared to the first hydraulic hose H1. Therefore, even if the second hydraulic hose H2 moves wildly when the second boom 31B rotates, the extent of the movement is sufficiently smaller than that of the first hydraulic hose H1. Therefore, it can be considered that the risk of the second hydraulic hose H2 moving wildly and coming into contact with surrounding components and being damaged when the second boom 31B rotates is sufficiently low.

[0068] [5. Pipe support and hose guide on the second boom] As shown in FIG. 13, the second boom base end 31B-e has a base-side pipe insertion hole 31B-e1. Furthermore, the base-side pipe insertion hole 31B-e1 has a protruding portion 31B-e2 that protrudes toward the inside of the second boom 31B. A pipe 31H (see FIG. 16) is inserted into the base-side pipe insertion hole 31B-e1. The second boom base end 31B-e supports the base-side outer peripheral end 31Hp (see FIG. 16) of the pipe 31H inserted into the base-side pipe insertion hole 31B-e1 at the position of the base-side pipe insertion hole 31B-e1, and further holds the pipe 31H with the protruding portion 31B-e2. This allows the second boom 31B to stably support the pipe 31H.

[0069] Additionally, the outer peripheral end portion of the tip side of the tube 31H is fitted into the second boom tip section 31B-t shown in FIGS. 6 and 7. As a result, the tip side end of the tube 31H is supported by the second boom tip section 31B-t. The second boom tip section 31B-t has a tip side opening 31B-t1. The inner diameter of the tip side opening 31B-t1 is approximately the same as the inner diameter of the tube 31H. Therefore, the tip side end of the tube 31H is supported by the second boom tip section 31B-t without protruding from the tip side opening 31B-t1 toward the third boom 31C.

[0070] For this reason, it can also be said that second boom base end 31B-e and second boom tip end 31B-t constitute a pipe support part that supports pipe 31H. In other words, second boom 31B has second boom base end 31B-e and second boom tip end 31B as pipe support parts.

[0071] 12, the second boom 31B has a fixing part 320. The fixing part 320 is fixed to the end face of the second boom base end 31B-e on the first boom 31A side, for example, by fastening bolts. In other words, the second boom 31B has a fixing part 320 that is fixed to the pipe support part. Note that the pipe support part described below refers to the second boom base end 31B-e, of the second boom base end 31B-e and the second boom tip end 31B-t, to which the fixing part 320 is fixed.

[0072] Figure 14 is a perspective view showing the configuration of the fixed part 320. The fixed part 320 has a first hose guide 321, a second hose guide 322, and a connecting part 323. In other words, the hydraulic excavator 1 has the first hose guide 321. The first hose guide 321 is a guide member that guides the second hydraulic hose H2 passing through the above-mentioned first space SP1 to the gap T4 between the left side surface 31B-L of the second boom 31B and the offset cylinder 31f shown in Figure 12.

[0073] The second hose guide 322 is provided to face the outer peripheral end 31Hp (see FIG. 16) of the pipe 31H supported by the second boom base end 31B-e serving as the pipe support part. The second hose guide 322 is located on the opposite side of the connecting part 323 from the first hose guide 321. The connecting part 323 connects the first hose guide 321 and the second hose guide 322. Therefore, the fixing part 320 is formed as an integrated part of the first hose guide 321, the second hose guide 322, and the connecting part 323. The connecting part 323 has bolt insertion holes 323a formed in two locations. A bolt Bo (see FIG. 12) is inserted into each of the bolt insertion holes 323a.

[0074] The procedure for fixing the fixing part 320 to the second boom base end 31B-e is as follows. First, the pipe 31H is inserted into the interior of the second boom 31B shown in FIG. 15 through the base-end pipe insertion hole 31B-e1 of the second boom base end 31B-e. FIG. 16 shows the state in which the pipe 31H has been inserted into the interior of the second boom 31B. Next, a bolt Bo is inserted into the bolt insertion hole 323a of the connecting part 323 of the fixing part 320 and screwed into the threaded hole Q of the second boom base end 31B-e. As a result, as shown in FIG. 17, the fixing part 320 is fixed to the second boom base end 31B-e, and the second hose guide 322 of the fixing part 320 is positioned so as to cover the outer peripheral end 31Hp (see FIG. 16) of the pipe 31H from the first boom 31A side. At the same time, the first hose guide 321 It is located closer to the base end (first boom 31A side) than the offset cylinder 31f, and is located between the left side surface 31B-L of the second boom 31B and the offset cylinder 31f when viewed from the first boom 31A side.

[0075] As shown in Fig. 14, the first hose guide 321 has a vertically long hose insertion hole 321a. For this reason, as shown in Fig. 12, by passing the second hydraulic hose H2 passing through the first space SP1 through the hose insertion hole 321a of the first hose guide 321, it becomes easy to guide the second hydraulic hose H2 into the gap T4. This makes it easy to route the second hydraulic hose H2 passing through the first space SP1 and the gap T4. Furthermore, even if the second hydraulic hose H2 moves wildly during an offset operation in which the second boom 31B rotates, the movement is suppressed by the restriction of the first hose guide 321. This reliably suppresses damage to the second hydraulic hose H2 caused by movement wildly.

[0076] Outer peripheral end 31Hp of pipe 31H supported by the pipe support part (second boom base end 31B-e) is covered by second hose guide 322. Fixing part 320 having second hose guide 322 is fixed to second boom base end 31B-e by bolting, and therefore the position of second hose guide 322 is also fixed. Therefore, after fixing part 320 is fixed to second boom base end 31B-e, pipe 31H inserted into second boom base end 31B-e is prevented from slipping out toward the first boom 31A side.

[0077] By fixing the connecting part 323 to the second boom base end 31B-e, the first hose guide 321 and the second hose guide 322 connected to the connecting part 323 can be installed at the second boom base end 31B-e simultaneously (as an integrated part). From this perspective, it is desirable that the fixing part 320 has a configuration including the connecting part 323 that connects the first hose guide 321 and the second hose guide 322.

[0078] [6. Supplementary Information] The hydraulic excavator 1 may be configured to use an electric motor instead of the engine 40 as a power source.

[0079] [7. Notes] The hydraulic excavator 1 described in this embodiment can also be expressed as a work machine described in the following supplementary notes.

[0080] The work machine in Appendix (1) is A work machine having a first boom supported so as to be rotatable in the vertical direction relative to a machine body, a second boom supported so as to be rotatable in the left-right direction relative to the first boom; a third boom supported so as to be rotatable in the left-right direction relative to the second boom; a hydraulic hose extending along the back surface of the first boom, the first boom has an opening on the back surface, The hydraulic hose passes through the opening from the outside to the inside of the first boom, passes through the inside of the second boom, and extends toward the third boom.

[0081] The work machine of supplementary note (2) is the work machine of supplementary note (1), the second boom is rotatably supported by the first boom at positions opposite to each other across a first space in an axial direction of a first shaft portion that serves as a rotation axis when the second boom rotates relative to the first boom, the third boom is rotatably supported by the second boom at positions opposite to each other across a second space in an axial direction of a second shaft portion that serves as a rotation axis when the third boom rotates relative to the second boom, The hydraulic hose is disposed through the first space and the second space.

[0082] The work machine of supplementary note (3) is the work machine of supplementary note (2), The first shaft portions are arranged side by side in the axial direction with the first space interposed therebetween.

[0083] The work machine of supplementary note (4) is the work machine described in supplementary note (3), the first boom has first rotating shaft insertion portions through which the individual first shaft portions are inserted and which rotatably support the second boom, The first rotation shaft insertion portions are arranged side by side in the axial direction of the first shaft portion, with the first space interposed therebetween.

[0084] The work machine of supplementary note (5) is a work machine according to any one of supplementary notes (2) to (4), The second shaft portions are arranged side by side in the axial direction with the second space interposed therebetween.

[0085] The work machine of supplementary note (6) is the work machine according to supplementary note (5), the third boom has second rotating shaft insertion portions through which the respective second shaft portions are inserted and which are rotatably supported by the second boom, The second rotation shaft insertion portions are arranged side by side in the axial direction of the second shaft portion, with the second space interposed therebetween.

[0086] The work machine of supplementary note (7) is a work machine according to any one of supplementary notes (1) to (6), the second boom has a third space therein, The hydraulic hose is disposed through the third space.

[0087] The work machine of supplementary note (8) is the work machine according to supplementary note (7), the second boom has a pipe therein extending from the first boom side toward the third boom side, The tube has the third space.

[0088] The work machine of supplementary note (9) is the work machine according to supplementary note (8), an offset cylinder disposed to the side of the second boom; a pair of support portions connected to side surfaces of the second boom and supporting a base end portion of the offset cylinder, When the hydraulic hose is a first hydraulic hose, the work machine further includes a second hydraulic hose that passes through the opening of the first boom and the first space and is connected to the offset cylinder; The second hydraulic hose is sandwiched between the pair of support portions and is arranged to pass through a gap formed between the base end portion and the side surface.

[0089] The work machine of supplementary note (10) is the work machine according to supplementary note (9), The hydraulic pressure hose further includes a first hose guide that guides the second hydraulic hose passing through the first space into the gap.

[0090] The work machine of supplementary note (11) is the work machine according to supplementary note (10), The second boom is A pipe support portion that supports the pipe. a fixing portion fixed to the tube support portion, The fixing portion has a second hose guide provided so as to face the outer peripheral end of the pipe supported by the pipe support portion.

[0091] The work machine of supplementary note (12) is the work machine according to supplementary note (11), the fixing portion further includes a connecting portion that connects the first hose guide and the second hose guide, The connector is secured to the tube support.

[0092] The work machine of supplementary note (13) is a work machine according to any one of supplementary notes (1) to (12), further comprising an arm supported rotatably in the vertical direction relative to the third boom, a rotation shaft of the arm extending in the left-right direction and supported by the third boom, The hydraulic hose that passes through the inside of the second boom and extends toward the arm passes above the rotation shaft of the arm.

[0093] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these, and the invention can be expanded or modified without departing from the spirit of the invention. [Industrial Applicability]

[0094] The present invention can be used in work machines such as construction machines. [Explanation of symbols]

[0095] 1. Hydraulic excavator (work machine) 4 Upper rotating body (aircraft) 31A First Boom 31A-b Back 31A-P opening 31B Second Boom 31C 3rd Boom 31H tube 31Hp outer edge 31f offset cylinder 32 Arm 32X Rotating Axis 311 First rotating shaft insertion part 312 Second rotating shaft insertion part 313 Offset cylinder support 313a Support part 320 Fixed part 321 No. 1 Hose Guide 322 Second Hose Guide 323 Connecting part 351 First shaft 352 Second shaft H hydraulic hose H1 First hydraulic hose H2 No. 2 hydraulic hose SP1 1st space SP2 2nd space SP3 3rd space T4 gap

Claims

1. A work machine including a first boom supported rotatably in the vertical direction relative to a machine body, a second boom supported so as to be rotatable in the left-right direction relative to the first boom; a third boom supported so as to be rotatable in the left-right direction relative to the second boom; a hydraulic hose extending along the back surface of the first boom, the first boom has an opening on the back surface, The hydraulic hose passes through the opening from the outside of the first boom to the inside thereof, passes through the inside of the second boom, and extends toward the third boom.

2. the second boom is rotatably supported by the first boom at positions opposite to each other across a first space in an axial direction of a first shaft portion that serves as a rotation axis when the second boom rotates relative to the first boom, the third boom is rotatably supported by the second boom at positions opposite to each other across a second space in an axial direction of a second shaft portion that serves as a rotation axis when the third boom rotates relative to the second boom, The work machine according to claim 1 , wherein the hydraulic hose is disposed through the first space and the second space.

3. The work machine according to claim 2 , wherein the first shaft portions are arranged side by side in the axial direction with the first space interposed therebetween.

4. the first boom has first pivot shaft insertion portions through which the individual first shaft portions are inserted and which rotatably support the second boom, The work machine according to claim 3 , wherein the first rotary shaft insertion portions are arranged side by side in the axial direction of the first shaft portion, with the first space interposed therebetween.

5. The work machine according to claim 2 , wherein the second shaft portions are arranged side by side in the axial direction with the second space interposed therebetween.

6. the third boom has second rotating shaft insertion portions through which the respective second shaft portions are inserted and which are rotatably supported by the second boom, The work machine according to claim 5 , wherein the second rotary shaft insertion portions are arranged side by side in the axial direction of the second shaft portion, with the second space interposed therebetween.

7. the second boom has a third space therein, The work machine according to claim 1 , wherein the hydraulic hose is disposed through the third space.

8. the second boom has a pipe therein extending from the first boom side toward the third boom side, The work machine of claim 7 , wherein the pipe includes the third space.

9. an offset cylinder disposed to the side of the second boom; a pair of support portions connected to side surfaces of the second boom and supporting a base end portion of the offset cylinder, When the hydraulic hose is a first hydraulic hose, the work machine further includes a second hydraulic hose that passes through the opening of the first boom and the first space and is connected to the offset cylinder; The work machine according to claim 8 , wherein the second hydraulic hose is sandwiched between the pair of support portions and arranged to pass through a gap formed between the base end portion and the side surface.

10. The work machine according to claim 9 , further comprising a first hose guide that guides the second hydraulic hose passing through the first space into the gap.

11. The second boom is A pipe support portion that supports the pipe. a fixing portion fixed to the tube support portion, The work machine according to claim 10 , wherein the fixing portion has a second hose guide provided so as to face an outer peripheral end portion of the pipe supported by the pipe support portion.

12. the fixing portion further includes a connecting portion that connects the first hose guide and the second hose guide, The work machine of claim 11 , wherein the coupling is secured to the tube support.

13. further comprising an arm supported rotatably in the vertical direction relative to the third boom, a rotation shaft of the arm extends in the left-right direction and is supported by the third boom, The work machine according to claim 1 , wherein the hydraulic hose that passes through the inside of the second boom and extends toward the arm passes above the rotation shaft of the arm.

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