working machine

Abstract

In order to provide a working machine capable of increasing the height of the top end portion of a boom and reducing the weight of the boom, a boom (11) is configured such that, at a highest raised position (19) at which the boom (11) is swung to the uppermost position, a first portion (11Ca) between a middle portion (11Cc) and a boom base portion (11A) extends upward from the boom base portion (11A) toward the middle portion (11Cc), a second portion (11Cb) between the middle portion (11Cc) and a boom top end portion (11B) extends in a posture in which it moves forward as it moves upward from the middle portion (11Cc), and a first straight line (26a) that is orthogonal to a bucket lever shaft (43) and the first cylinder shaft (37) and that extends downward more than the first cylinder shaft (37) passes in front of a machine body (2).

Description

Technical Field

[0001] This invention relates to a work machine. Background Technology

[0002] Previously, there was a work machine disclosed in Patent Document 1.

[0003] The work machine disclosed in Patent Document 1 has a boom that is supported by a boom support body located at the front of the machine body in a manner that allows it to swing up and down. The boom includes: a boom base pivotally supported by the boom support body; a boom tip pivotally supporting the stick; and a boom body portion that bends in the middle section along the length of the boom, between the boom base and the boom tip portion. The boom body portion includes: a first portion between the middle portion and the boom base; and a second portion between the middle portion and the boom tip portion.

[0004] When the boom is swung to its highest lifting position, the boom is in a posture where the first part extends upward from the base of the boom, and the second part extends forward in an inclined direction as it moves upward from the middle part.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Publication No. 2020-148070 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] However, there is a desire to increase the height of the boom tip when the boom is in its highest raised position. Additionally, there is a desire to reduce the weight of the boom.

[0010] The present invention addresses the aforementioned problems and aims to provide a work machine that can increase the height of the top of the boom when the boom is in its highest raised position and reduce the weight of the boom.

[0011] means for solving problems

[0012] An embodiment of the present invention provides a work machine comprising: a body; a boom support body disposed at the front of the body; a boom including: a boom base supported on the boom support body via a boom pivot; a boom tip supported on a stick pivot via a stick pivot to enable swinging; and a boom body portion formed between the boom base and the boom tip portion and bent at the middle in the boom length direction, the boom being capable of swinging up and down about the boom pivot; and a boom cylinder disposed on the front side of the boom, one end of which is supported on the front side of the boom body portion via a first cylinder pivot, and the other end of which is supported on the front side of the boom body portion. One end is pivotally supported on the boom support body via the second cylinder support shaft. The boom swings by extension and retraction. When the boom swings to its highest lifting position, the boom is in the following posture: a first portion between the middle portion and the boom base extends upward from the boom base toward the middle portion; a second portion between the middle portion and the boom tip extends forward in an inclined direction as it moves upward from the middle portion; and a first straight line, orthogonal to the stick support shaft and the first cylinder support shaft and extending downward compared to the first cylinder support shaft, passes through the front of the machine body.

[0013] In addition, the work machine has a driver's seat mounted on the machine body, and the boom is configured such that the extension line of the back of the second part at the highest lifting position, that is, the first extension line extending downward from the back of the second part, passes through the front of the driver's seat.

[0014] In addition, the work machine has a driver's seat mounted on the machine body, and the boom is configured such that the extension line of the front of the second part at the highest raised position, that is, the second extension line extending downward from the front of the second part, passes through the front of the driver's seat.

[0015] Furthermore, at the highest raised position, when a straight line orthogonal to the stick support shaft and the boom support shaft is designated as the second straight line, a straight line orthogonal to the second straight line and the first cylinder support shaft is designated as the third straight line, the intersection of the second straight line and the third straight line is designated as the first intersection point, the intersection of the third straight line and the front of the boom body is designated as the second intersection point, and the intersection of the third straight line and the back of the boom body is designated as the third intersection point, the first distance between the first intersection point and the second intersection point is less than the second distance between the second intersection point and the third intersection point.

[0016] Furthermore, at the highest raised position, when the vertical line orthogonal to the stick support axis is designated as the fourth straight line, the straight line orthogonal to the fourth straight line and the first cylinder support axis is designated as the fifth straight line, the intersection of the fourth straight line and the fifth straight line is designated as the fifth intersection point, and the intersection of the fifth straight line and the back of the boom body is designated as the sixth intersection point, the fifth distance between the fifth intersection point and the sixth intersection point is less than the sixth distance between the axis of the stick support axis and the fifth intersection point.

[0017] Furthermore, at the highest raised position, when the vertical line orthogonal to the boom support axis is designated as the sixth straight line and the vertical line orthogonal to the second cylinder support axis is designated as the seventh straight line, the seventh distance between the fourth straight line and the seventh straight line is less than the eighth distance between the sixth straight line and the seventh straight line.

[0018] In addition, the sixth distance is greater than the ninth distance in the vertical direction between the fifth straight line and the upper edge of the side of the boom base.

[0019] Additionally, the boom base has a pivot support portion that is pivotally supported via the boom support shaft, and a connection portion that connects to the first portion of the boom body. Furthermore, when the boom is swung to the highest raised position, the pivot support portion extends in an inclined direction that moves rearward from the boom support shaft side upward, and the connection portion bends between the pivot support portion and the connection portion in a manner that extends upward from the pivot support portion.

[0020] In addition, the first curvature angle formed by the front of the first part and the front of the second part is greater than the second curvature angle formed by the front of the pivot support part and the front of the connecting part.

[0021] Additionally, the work machine includes: a work tool, supported on the stick via a work tool support pivot, capable of swinging between a work tool loading position closest to the stick at the top and a work tool unloading position furthest from the stick at the top by swinging around the work tool support pivot; a stick cylinder, causing the stick to swing in a stick loading direction close to the boom and in a stick unloading direction away from the boom; and a stick loading limiter, limiting the travel of the stick cylinder in the stick loading direction so that the swing track of the top of the work tool is separated from the boom cylinder by a predetermined interval or more.

[0022] Additionally, the work machine includes: a work tool, supported on the boom via a work tool support shaft pivot, capable of swinging between a work tool loading position closest to the boom and a work tool unloading position furthest from the boom by swinging around the work tool support shaft; a work tool cylinder, causing the work tool to swing in a work tool loading direction near the work tool loading position and in a work tool unloading direction near the work tool unloading position; and a work tool loading restriction part, limiting the travel of the work tool cylinder in the work tool loading direction so that the swing track of the top of the work tool is separated from the boom cylinder by a predetermined interval or more.

[0023] Invention Effects

[0024] According to the aforementioned work machine, when the boom is swung upwards to its highest lifting position, a first portion of the boom body extends upwards from the base toward the middle, and a second portion of the boom body bends in an inclined direction that moves forward from the middle upwards. In this work machine, by configuring a first straight line that is orthogonal to the stick support shaft and the first cylinder support shaft and extends downwards relative to the first cylinder support shaft, passing through the front of the machine body, the boom's bending angle (the angle between the first and second portions) is larger than before. Therefore, the height of the boom tip when the boom is in its highest lifting position can be increased, and the weight of the boom can also be reduced. Attached Figure Description

[0025] Figure 1 This is a side view of the machine.

[0026] Figure 2 This is a side view of the working device.

[0027] Figure 3 It is a three-dimensional view of the boom being supported by a pivot on a swing bracket.

[0028] Figure 4 This is a side view used to illustrate the shape of the boom.

[0029] Figure 5 This is a side view used to illustrate the shape of the boom.

[0030] Figure 6 This is a side view used to illustrate the shape of the boom.

[0031] Figure 7 This is a side view used to illustrate the shape of the boom.

[0032] Figure 8 This is a side view used to illustrate the effect of the boom in this embodiment.

[0033] Figure 9 This is a side view of the boom in the lowered position.

[0034] Figure 10 This is a diagram showing the hydraulic system of the work machine.

[0035] Figure 11 It is a diagram showing the changing state of the boom's swing position.

[0036] Figure 12 This is a side view of the winnowing basket in operation.

[0037] Figure 13 This is a 3D diagram showing the configuration of the hydraulic hoses. Detailed Implementation

[0038] Hereinafter, an embodiment of the present invention will be described with appropriate reference to the accompanying drawings.

[0039] Figure 1 This is a schematic side view showing the overall structure of the work machine 1 according to this embodiment. In this embodiment, a backhoe excavator is exemplified as a rotary work machine as the work machine 1.

[0040] like Figure 1 As shown, the work machine 1 includes a body (rotary table) 2, a traveling device 3, and a working device 4. A driver's seat 6 for the operator (driver) is mounted on the body 2. Additionally, a top cover 5 is mounted on the body 2. The top cover 5 is a driver's seat protection device that protects the driver's seat 6. Alternatively, a cab surrounding the driver's seat 6 can be mounted instead of the top cover 5 as a driver's seat protection device.

[0041] In this embodiment, the direction will be towards the front of the operator seat 6 of the machine 1. Figure 1 Arrow A1 direction) as the front (front of the machine), will be directed towards the operator's rear ( Figure 1 (Arrow A2 direction) as the rear (rear of the machine) Figure 1 Arrow K1 is used to indicate the forward / backward direction (forward / backward direction of the aircraft). Additionally, the direction towards the operator's left ( Figure 1 The near-front side) is on the left, facing the direction to the operator's right ( Figure 1 The inside side (of the inside) will be explained as the right side.

[0042] Furthermore, the horizontal direction, which is orthogonal to the front-back direction K1, will be described as the width direction of the fuselage. The direction from the center of the fuselage 2 towards the right or left side in the width direction will be described as the outer side of the fuselage width direction. In other words, the outer side of the fuselage width direction is the direction away from the center of the fuselage 2's width direction. Conversely, the inner side of the fuselage width direction is the direction closer to the center of the fuselage 2's width direction.

[0043] like Figure 1 As shown, the travel device 3 is a tracked travel device that supports the machine body 2 in a drivable manner. It has a travel frame 3A, a first travel device 3L located on the left side of the travel frame 3A, and a second travel device 3R located on the right side of the travel frame 3A. The first travel device 3L and the second travel device 3R are driven by a travel motor M1, which is composed of a hydraulic motor (hydraulic actuator). In this embodiment, a tracked travel device 3 is used, but it is not limited to this; a wheeled or other type of travel device may also be used.

[0044] A bulldozer blade device 7 is installed at the front of the traveling device 3. The bulldozer blade device 7 can raise and lower the scraper (bullfarrow) 7A by extending and retracting the bulldozer blade cylinder (hydraulic actuator) (not shown).

[0045] like Figure 1 As shown, the machine body 2 has a rotating base plate 15 that rotates around a rotation axis X1 extending in the vertical direction. The rotating base plate 15 is formed of steel plate or the like and constitutes the bottom of the machine body 2. A counterweight 14 is provided at the rear of the machine body 2. The machine body 2 (rotating base plate 15) is supported by the travel device 3 via a rotary bearing 8 in a manner that allows it to rotate around the rotation axis X1.

[0046] like Figure 1 As shown, the working machine 1 has a support bracket 9 and a swing bracket (boom support) 10. The support bracket 9 is arranged to protrude forward from the machine body 2. That is, the support bracket 9 protrudes forward more than the front surface 2a of the machine body 2. The swing bracket 10 is a component that supports the working device 4 and is arranged at the front of the machine body 2. In detail, the swing bracket 10 is mounted at the front of the support bracket 9 so as to be able to swing about a swing axis 10a extending in the vertical direction. Therefore, the swing bracket 10 can rotate in the width direction of the machine body (horizontally about the swing axis 10a). The swing bracket 10 can swing by the extension and retraction of a swing cylinder (hydraulic actuator) not shown.

[0047] like Figure 1As shown, a prime mover E1 is mounted at the rear of the machine body 2. Specifically, the prime mover E1 is mounted on a rotating base plate 15. The prime mover E1 is a diesel engine. Alternatively, the prime mover E1 can be a gasoline engine, an electric motor, or a hybrid type incorporating both an engine and an electric motor. A driver's unit 18 is mounted in front of the prime mover E1 of the machine body 2. This driver's unit 18 includes a driver's seat 6, a travel lever 16 positioned in front of the driver's seat 6, a control device 17L positioned to the left of the driver's seat 6, and a control device 17R positioned to the right. The travel lever 16 is the operating component for operating the travel device 3. The control devices 17L and 17R are, for example, devices for operating the working device 4 (swinging the boom 11, swinging the stick 12, and swinging the bucket 13) and rotating the machine body 2. A foot pedal 21 forming the bottom surface is provided on the upper surface of the machine body 2 and in front of the driver's seat 6.

[0048] like Figure 1 , Figure 2 As shown, the working device 4 includes a boom assembly 30, a stick assembly 40, and a working tool assembly 50. The boom assembly 30 includes a boom 11 and a boom cylinder C2. The stick assembly 40 includes a stick 12 and a stick cylinder C3. The working tool assembly 50 includes a bucket 13 as a working tool and a bucket cylinder C4 as a working tool cylinder.

[0049] like Figure 1 , Figure 2 As shown, the boom 11 includes a boom base 11A, a boom tip 11B, and a boom body 11C. The boom base 11A is pivotally supported on the swing bracket 10 via a boom support shaft 35. Specifically, the boom base 11A is supported on the first pivot support portion 23 of the swing bracket 10 via a boom support shaft 35 having an axis extending along the width direction of the machine body, in a swinging (free rotation) manner. That is, the boom 11 swings (up and down) about the boom support shaft 35 in the vertical direction.

[0050] like Figure 3 As shown, the boom base 11A is formed in a two-pronged shape. Specifically, the boom base 11A has a pivot support portion 11Aa that is pivotally supported via a boom support shaft 35, and a connecting portion 11Ab that connects to the boom body portion 11C (first portion 11Ca). A pair of pivot support portions 11Aa are provided in the width direction of the machine body, arranged such that the first pivot support portion 23 is sandwiched between the left and right pivot support portions 11Aa in the width direction of the machine body. A space 51 is formed between the connecting portion 11Ab and the swing bracket 10, and between the first pivot support portions 23.

[0051] like Figure 2As shown, the boom base 11A is bent between the pivot support portion 11Aa and the connecting portion 11Ab (the middle part of the boom's length direction). In other words, the boom base 11A has a bent portion between the pivot support portion 11Aa and the connecting portion 11Ab.

[0052] like Figure 1 , Figure 2 As shown, the boom tip 11B supports the stick 12 so that it can swing freely. Specifically, the boom tip 11B supports the base pivot of the stick 12 via a stick support shaft 43 having an axis extending along the width direction of the machine body, allowing it to swing. As... Figure 3 As shown, the top part 11B of the boom is formed into two strands, which are arranged to clamp the base of the stick 12.

[0053] like Figure 1 , Figure 2 As shown, the boom body 11C is the portion disposed between the boom base 11A and the boom tip 11B. The boom body 11C is a rectangular prism with a rectangular cross-section, formed by welding the sides of four long strips of sheet metal together along the length direction of the boom 11 (boom length direction), and it bends at the middle. Specifically, the boom body 11C bends at the middle portion 11Cc in the boom length direction, having a first portion 11Ca between the middle portion (bent portion) 11Cc and the boom base 11A, and a second portion 11Cb between the middle portion 11Cc and the boom tip 11B. In other words, the boom body 11C bends between the first portion 11Ca and the second portion 11Cb. A lower bracket 33 is provided on the front side of the middle part 11Cc (bent part) of the boom body 11C, and an upper bracket 34 is provided on the back side (upper side) of the middle part 11Cc (bent part) of the boom body 11C.

[0054] like Figure 2 As shown, with the swing bracket 10 and boom 11 facing the front of the machine body, in the raised position 19 where the boom 11 swings upward, the boom 11 is positioned such that the first portion 11Ca extends upward from the boom base 11A toward the middle portion 11Cc, and the second portion 11Cb extends forward in an inclined direction as it moves upward from the middle portion 11Cc. In the machine 1 of this embodiment, the boom 11 is arranged in front of the top cover (cabin) 5 such that it overlaps with the top cover (cabin) 5 when viewed from the front, and is configured such that when the boom 11 is in the raised position 19, the upward swing of the boom 11 stops at a position where the boom 11 does not interfere with the top cover (cabin) 5. In this embodiment, Figure 1 , Figure 2 The raised position 19 shown indicates that the boom 11 is swung to the highest raised position.

[0055] In addition, at the raised position 19 of the boom 11, the boom base 11A extends in an inclined direction with the pivot support portion 11Aa moving backward from the side of the boom support shaft 35 upward, and the connecting portion 11Ab bends in a manner that extends upward from the pivot support portion 11Aa.

[0056] like Figure 7 As shown, the bending angle (first bending angle) 27 of the boom body 11C (boom 11) is larger than the bending angle (second bending angle) 39 of the boom base 11A. The first bending angle 27 is the angle formed by the front face 11Ca1 of the first part 11Ca and the front face 11Cb1 of the second part 11Cb. The second bending angle 39 is the angle formed by the front face 11Aa1 of the pivot support part 11Aa and the front face 11Ab1 of the connecting part 11Ab.

[0057] The boom 11 is not limited to the structure described above. The boom base 11A and boom tip 11B are formed separately from the boom body 11C, but the boom 11 may also be formed integrally with the boom base 11A, boom tip 11B, and boom body 11C. Furthermore, the boom base 11A may not be bent. Additionally, the boom base 11A and boom tip 11B may not be formed as two strands. In this embodiment, the boom base 11A and boom tip 11B are formed of cast iron, and the boom body 11C is constructed by welding four plates together into a cylindrical shape; however, the materials of the boom base 11A, boom tip 11B, and boom body 11C are not limited to this.

[0058] like Figure 2 As shown, boom cylinder C2 is a telescopic hydraulic cylinder (hydraulic actuator) that causes boom 11 to swing (rotate). Specifically, boom cylinder C2 is located on the front side of boom 11 (the front side of boom 11's body). Furthermore, one end of boom cylinder C2 is pivotally supported on the front side of boom body 11C via a cylinder support shaft (first cylinder support shaft) 37 with an axis having a axis in the width direction of the body, and the other end is pivotally supported on swing bracket 10 via a cylinder support shaft (second cylinder support shaft) 36 with an axis having a axis in the width direction of the body. Boom cylinder C2 causes boom 11 to swing by telescopic extension.

[0059] More specifically, the boom cylinder C2 has a cylindrical cylinder portion 32A and a rod 32B that is slidably inserted into the cylinder portion 32A at one end. The boom cylinder C2 is positioned on the side of the boom 11 opposite to the stick 12 when the stick 12 swings in the stick loading direction D1. That is, the boom cylinder C2 is positioned on the lower part of the front side (front surface side) of the boom 11. The top end of the boom cylinder C2 (the protruding end of the rod 32B) is supported by the lower bracket 33 via the first cylinder support 37 and is able to swing freely. The base end of the boom cylinder C2 (the bottom side of the cylinder portion 32A) is supported by the second pivot support 24 of the swing bracket 10 via the second cylinder support 36 and is able to swing freely. Therefore, the boom assembly 30 (boom 11) can rotate about the boom support 35 of the first pivot support 23 and can swing freely in the upward or downward direction. In addition, a protective member (cylinder protector) may be provided on the surface of the boom cylinder C2 on the side (lower side) of the stick 12 to prevent other objects from contacting the stick 32B and / or the cylinder part 32A.

[0060] like Figure 2 As shown, the stick 12 is elongated along its length. The base of the stick 12 is supported by the boom tip 11B of the driven boom 11 via the stick support shaft 43, allowing it to swing freely. In addition, an upper bracket 44 is provided on the upper surface of the base of the stick 12.

[0061] like Figure 2 As shown, the boom cylinder C3 is a retractable hydraulic cylinder (hydraulic actuator) that swings the boom 12. The base end of the boom cylinder C3 is supported by the upper bracket 34 of the driven boom 11 via a cylinder support shaft (third cylinder support shaft) 38 having an axis in the width direction of the machine body, allowing it to swing freely. The top end of the boom cylinder C3 is supported by the upper bracket 44 via a cylinder support shaft (fourth cylinder support shaft) 46 having an axis in the width direction of the machine body, allowing it to swing freely. Therefore, the boom device 40 (boom 12) can rotate about the boom support shaft 43 of the boom 11, and the boom device 40 (boom 12) can swing freely in the upward or downward direction (forward or backward). That is, as... Figure 2 As shown, the stick 12 is pivotally supported on the boom 11 in a manner that allows it to swing in a stick loading direction D1 approaching the boom 11 and a stick unloading direction D2 away from the boom 11. In this embodiment, the stick 12 swings in the stick loading direction D1 by extending the stick cylinder C3 (travel in the stick loading direction D1), and swings in the stick unloading direction D2 by retracting the stick cylinder C3 (travel in the stick unloading direction D2).

[0062] like Figure 2As shown, the bucket 13 is supported by the top end of the stick 12 via a pivot (bucket support shaft) 57 having an axis in the width direction of the machine body, allowing it to swing freely. A linkage mechanism 53 is provided between the bucket 13 and the top end of the stick 12. The bucket 13 has a part for digging soil, sand, etc., namely the bucket body 13a, and a part mounted on the stick 12 and the linkage mechanism 53, namely the mounting bracket 13c. The bucket body 13a has a bottom surface 13b and a top end (claw portion) 58.

[0063] like Figure 2 As shown, the bucket cylinder C4 is composed of a retractable hydraulic cylinder (hydraulic actuator) that swings the bucket 13. The base end of the bucket cylinder C4 is supported by the upper bracket 44 of the boom 12 via a cylinder support shaft (fifth cylinder support shaft) 48 having a shaft extending in the width direction of the machine body, allowing it to swing freely. The top end of the bucket cylinder C4 is supported by the cylinder support shaft (sixth cylinder support shaft) 56 of the linkage mechanism 53, allowing it to swing freely about the shaft extending in the width direction of the machine body. Therefore, the working tool device 50 (bucket 13) is provided on the top end side of the boom 12 in a manner that enables it to perform shoveling (digging) and dumping actions. The shoveling (digging) action refers to the action of swinging the top end 58 of the bucket 13 toward the boom 11 (boom 12), i.e., the bucket shoveling direction (working tool shoveling direction) D3, for example, the action when digging sand or soil. In addition, the dumping action refers to the action of swinging the top part 58 of the bucket 13 away from the boom 11 (stick 12), i.e., the bucket dumping direction (operating tool dumping direction) D4. For example, it is the action of dropping (discharging) the excavated sand and soil.

[0064] Therefore, as Figure 2 As shown, the bucket 13 can swing between the position where the bucket cylinder C4 is at its maximum extension (maximum stroke in the bucket loading direction D3), i.e., the bucket loading position (working tool loading position) Y1 where the top part 58 is closest to the stick 12, and the position where the bucket cylinder C4 is at its maximum retraction (maximum stroke in the bucket loading direction D4), i.e., the bucket unloading position (working tool unloading position) Y2 where the top part 58 is furthest from the stick 12. Figure 2 In the text, M3 represents the swing track of the top part 58 of the bucket 13 when it moves between the bucket loading position Y1 and the bucket unloading position Y2.

[0065] The work machine 1 can replace the bucket 13 or, based on the bucket 13, install other work tools (hydraulic accessories) that can be driven by a hydraulic actuator. Examples of other work tools include hydraulic crushers, hydraulic shredders, angle sweepers, augers, pallet forks, sweepers, lawn mowers, snow blowers, etc.

[0066] like Figure 4As shown, the boom 11 is configured such that, in the raised position 19, a straight line (first straight line) 26a, orthogonal to the stick support shaft 43 (axis 43a) and the first cylinder support shaft 37 (axis 37a) and extending further downward than the first cylinder support shaft 37, passes in front of the machine body 2. In this embodiment, the first straight line 26a intersects the support bracket 9 behind the swing bracket 10.

[0067] In conventional swing-function work machines, the boom is configured such that, in its highest raised position, a straight line (the conventional first straight line) extending downwards from the first cylinder support shaft and perpendicular to the shaft axis of both the stick support shaft and the first cylinder support shaft intersects the machine body (rotary table) (near the center of the machine body in the longitudinal direction). In contrast, in this embodiment, the boom 11 is configured such that the first straight line 26a passes through the front of the machine body 2. That is, the angle of inclination of the first straight line 26a relative to the horizontal line in this embodiment is larger than that of the conventional first straight line. The angle of inclination of the first straight line 26a relative to the horizontal line increases with the increase of the bending angle 27 of the boom 11. Therefore, by configuring the first straight line 26a to pass through the front of the machine body 2, the boom 11 in this embodiment is formed such that the bending angle 27 of the boom 11 is larger (shallower) than that of the conventional boom.

[0068] By making the bending angle 27 of the boom 11 larger than that of the conventional boom, the top position of the boom 11 can be increased (thus increasing the height of the bucket 13, i.e., the bucket height). In addition, the weight of the boom 11 can also be reduced (the boom 11 is made lighter).

[0069] Reference Figure 8 This will be explained in detail. Figure 8 In the figure, the solid line represents the boom of this embodiment, and the double-dotted line represents the upper part of the boom 11 when the bending angle 27 of the boom 11 is smaller than that of this embodiment (for example, in the conventional case). Reference numeral 22 indicates an arc centered on the axis 35a of the boom support shaft 35, that is, an arc passing through the axis 43a of the stick support shaft 43 (with the line connecting the axis 35a of the boom support shaft 35 and the axis 43a of the stick support shaft 43 as its radius). When the straight line orthogonal to the stick support shaft 43 and the boom support shaft 35 is the same size in both the conventional and this embodiment, such as... Figure 8 As shown, in both the conventional and present embodiments, the height of the stick support shaft 43 is H1 higher in this embodiment than in the conventional embodiment, and the distance H2 between the stick support shaft 43 and the middle portion 11Cc of the boom body 11C is smaller in this embodiment than in the conventional embodiment. In other words, compared to the conventional embodiment, by increasing the boom bending angle 27, the top position of the boom 11 can be raised, and the weight of the boom 11 can be reduced.

[0070] In this embodiment, the bending angle 27 of the boom 11 is set to, for example, 140° to 170°. Preferably, the bending angle 27 is set to 145° to 165°. More preferably, the bending angle 27 is set to 150° to 160°.

[0071] In addition, in this embodiment, such as Figure 4 As shown, the boom 11 is configured such that the extension line of the back side 11Cb2 of the second part 11Cb when viewed from the side at the raised position 19, namely the first extension line 28a extending downward from the back side 11Cb2 of the second part 11Cb, passes in front of the driver's seat 6.

[0072] In conventional work machines with a swing function, the boom is configured such that, when viewed from the side at its highest lifting position, the extension line (the conventional first extension line) extending downwards from the back of the second part passes behind the operator's seat (near the back). In contrast, in this embodiment, the boom 11 is configured such that the first extension line 28a passes in front of the operator's seat 6. That is, the angle of inclination of the first extension line 28a relative to the horizontal line is larger than that of the conventional first extension line. The angle of inclination of the first extension line 28a relative to the horizontal line increases as the bending angle 27 of the boom 11 increases. Therefore, by configuring the first extension line 28a to pass in front of the operator's seat 6, the boom 11 of this embodiment is formed such that the bending angle 27 of the boom 11 is larger (shallower) than that of conventional booms. This allows for a higher tip position of the boom 11 and enables a reduction in the weight of the boom 11.

[0073] In addition, in this embodiment, such as Figure 4 As shown, the boom 11 is configured such that the extension line 28b of the front side 11Cb1 of the second part 11Cb at the raised position 19, that is, the second extension line 28b extending downward from the front side 11Cb1 of the second part 11Cb, passes in front of the driver's seat 6.

[0074] In conventional swing-arm booms, the boom is configured such that an extension line (the conventional second extension line) extending downwards from the front of the second portion at the highest lifting position passes through the front of the operator's seat. In contrast, in this embodiment, the boom 11 is configured such that the second extension line 28b passes through the front of the operator's seat 6. That is, the tilt angle of the second extension line 28b relative to the horizontal line is larger than that of the conventional second extension line. The tilt angle of the second extension line 28b relative to the horizontal line increases as the bending angle 27 of the boom 11 increases. Therefore, by configuring the second extension line 28b to pass through the front of the operator's seat 6, the boom 11 of this embodiment is formed such that the bending angle 27 of the boom 11 is larger (shallower) than that of the conventional boom. This allows for a higher tip position of the boom 11 and enables a reduction in the weight of the boom 11.

[0075] In addition, in this embodiment, such as Figure 5 As shown, in the raised position 19, when the straight line orthogonal to the stick support shaft 43 (axis 43a) and the boom support shaft 35 (axis 35a) is designated as the second straight line 26b, the straight line orthogonal to the second straight line 26b and the first cylinder support shaft 37 (axis 37a) is designated as the third straight line 26c, the intersection of the second straight line 26b and the third straight line 26c is designated as the first intersection point 29a, the intersection of the third straight line 26c with the front of the boom body 11C is designated as the second intersection point 29b, and the intersection of the third straight line 26c with the back of the boom body 11C is designated as the third intersection point 29c, the first distance 31a between the first intersection point 29a and the second intersection point 29b is smaller than the second distance 31b between the second intersection point 29b and the third intersection point 29c.

[0076] In conventional swing-arm machines, due to the small boom bending angle, the stick support shaft is positioned further forward and downward than the stick support shaft 43 in this embodiment, resulting in a larger first distance than a second distance. As the boom bending angle increases, the stick support shaft moves rearward and upward, decreasing the first distance. Therefore, in this embodiment, by making the first distance 31a smaller than the second distance 31b, the boom bending angle 27 of the boom 11 is increased compared to conventional methods. This allows for a higher tip position of the boom 11 and a reduction in the weight of the boom 11.

[0077] In addition, in this embodiment, such as Figure 5 As shown, when the intersection of the swing axis 10a at the raised position 19 and the third straight line 26c is set as the fourth intersection point 29d, the third distance 31c between the second intersection point 29b and the fourth intersection point 29d is smaller than the fourth distance 31d between the third intersection point 29c and the fourth intersection point 29d.

[0078] In addition, in this embodiment, such as Figure 6 As shown, in the raised position 19, when the vertical line orthogonal to the stick support shaft 43 (axis 43a) is designated as the fourth straight line 26d, the straight line orthogonal to the fourth straight line 26d and the first cylinder support shaft 37 (axis 37a) is designated as the fifth straight line 26e, the intersection of the fourth straight line 26d and the fifth straight line 26e is designated as the fifth intersection point 29e, and the intersection of the fifth straight line 26e and the back of the boom body 11C is designated as the sixth intersection point 29f, the fifth distance 31e between the fifth intersection point 29e and the sixth intersection point 29f is smaller than the sixth distance 31f between the axis 43a of the stick support shaft 43 and the fifth intersection point 29e.

[0079] When the boom's bending angle is increased from a state where the fifth distance is larger than the sixth distance, as the boom's bending angle increases, the intersection of the fourth straight line and the fifth point approaches the middle of the boom, and the fifth distance decreases. In this embodiment, by making the fifth distance 31e smaller than the sixth distance 31f, the top position of the boom 11 can be raised, and the weight of the boom 11 can be reduced.

[0080] In addition, in this embodiment, such as Figure 6 As shown, in the raised position 19, when the vertical line orthogonal to the boom support shaft 35 (axis 35a) is set as the sixth straight line 26f, and the vertical line orthogonal to the second cylinder support shaft 36 (axis 36a) is set as the seventh straight line 26g, the seventh distance 31g between the fourth straight line 26d and the seventh straight line 26g is smaller than the eighth distance 31h between the sixth straight line 26f and the seventh straight line 26g.

[0081] In conventional oscillating work machines, the seventh distance is larger than the eighth distance. As the boom's bending angle increases, the fourth straight line approaches the middle of the boom, and the seventh distance decreases. Therefore, in this embodiment, by making the seventh distance 31g smaller than the eighth distance 31h, the bending angle 27 of the boom 11 is increased compared to the conventional method. As a result, the top position of the boom 11 can be raised, and the weight of the boom 11 can be reduced.

[0082] In addition, in this embodiment, such as Figure 6 As shown, the sixth distance 31f is larger than the ninth distance 31i in the vertical direction between the fifth straight line 26e and the upper edge 11Ac of the side of the boom base 11A.

[0083] In conventional swing-operated machines, the sixth distance is smaller than the ninth distance. As the boom's bending angle increases, the stick support moves rearward and upward, increasing its height, and the sixth distance becomes longer. Therefore, in this embodiment, by making the sixth distance 31f larger than the ninth distance 31i, the bending angle 27 of the boom 11 is increased compared to the conventional method. This allows for a higher tip position of the boom 11 and a reduction in the weight of the boom 11.

[0084] Figure 9 This indicates the state when the boom 11 is in the downward swinging lowering position 25. Figure 9In the diagram, the double-dotted line 41 represents the first portion 11Ca of the boom 11 and the boom base 11A when the boom base 11A is not bent. In the solid line representing this embodiment, there is a gap between the front side of the boom 11 (first portion 11Ca) and the boom cylinder C2 (cylinder portion 32A) (a gap exists where the boom 11 and boom cylinder C2 do not interfere with each other). However, the first portion 11Ca of the boom 11 shown by the double-dotted line 41 interferes with the boom cylinder C2 (cylinder portion 32A). Therefore, without bending the boom base 11A, the boom 11 cannot be lowered to the lowering position 25 shown by the solid line. In other words, as in this embodiment, when the boom base 11A is bent, the boom 11 can be lowered further downwards compared to when the boom base 11A is not bent. In other words, in this embodiment, by bending the boom base 11A, the boom 11 can be lowered to a position where the boom 11 interferes with the boom cylinder C2 without bending the boom base 11A. Furthermore, in the lowered position 25, since the tip of the boom 11 is sufficiently lowered, digging depth can be ensured even if the bending angle 27 of the boom 11 is shallow. That is, in this embodiment, in addition to increasing the height of the bucket 13 when the boom 11 is in the raised position 19 and reducing the weight of the boom 11, it is also possible to ensure digging depth.

[0085] Figure 10 This is a diagram showing the hydraulic system of the working machine 1 that enables the working device 4 to operate.

[0086] like Figure 10 As shown, the hydraulic system of the work machine 1 includes a boom control valve 71, a stick control valve 72, a bucket control valve 73, a control device 60, operating devices 17L and 17R, a boom angle sensor 91, a stick angle sensor 92, and a work tool angle sensor 93.

[0087] The boom control valve 71, stick control valve 72, and bucket control valve 73 are respectively connected to the boom cylinder C2, stick cylinder C3, and bucket cylinder C4 via oil circuits. In addition, the boom control valve 71, stick control valve 72, and bucket control valve 73 are respectively connected to the hydraulic pump P1 that sprays working oil via oil circuits.

[0088] The boom control valve 71, the stick control valve 72, and the bucket control valve 73 are, for example, electromagnetic three-position switching valves.

[0089] Specifically, the boom control valve 71 is a direct-acting spool valve that can be switched to a first position 71A, a second position 71B, and a third position 71C by energizing or demagnetizing the first solenoid 71D and the second solenoid 71E. When the boom control valve 71 is switched to the first position 71A, the boom cylinder C2 extends due to the supply and discharge of working oil, and the boom 11 swings upward. On the other hand, when the boom control valve 71 is switched to the second position 71B, the boom cylinder C2 contracts due to the supply and discharge of working oil, and the boom 11 swings downward.

[0090] The stick control valve 72 is a direct-acting spool valve that can be switched to a first position 72A, a second position 72B, and a third position 72C by energizing or demagnetizing the first solenoid 72D and the second solenoid 72E. When the stick control valve 72 is switched to the first position 72A, the stick cylinder C3 is extended by the supply and discharge of working oil, and the stick 12 swings in the stick loading direction D1 (rearward and downward). On the other hand, when the stick control valve 72 is switched to the second position 72B, the stick cylinder C3 is retracted by the supply and discharge of working oil, and the stick 12 swings in the stick unloading direction D2 (forward and upward).

[0091] The bucket control valve 73 is a direct-acting spool valve that can be switched to a first position 73A, a second position 73B, and a third position 73C by energizing or demagnetizing the first solenoid 73D and the second solenoid 73E. When the bucket control valve 73 is switched to the first position 73A, the supply and discharge of working oil to the bucket cylinder C4 causes the bucket cylinder C4 to extend, and the bucket 13 swings in the tool loading direction D3 (digging direction). On the other hand, when the bucket control valve 73 is switched to the second position 73B, the supply and discharge of working oil to the bucket cylinder C4 causes the bucket cylinder C4 to retract, and the bucket 13 swings in the dumping direction D4.

[0092] The control device 60 includes a boom control unit 61, a stick control unit 62, and a bucket control unit 63, and controls the switching operations of the boom control valve 71, stick control valve 72, and bucket control valve 73. That is, the control device 60 controls the movements of the boom 11, stick 12, and bucket 13. The control device 60 can be implemented using logic circuits (hardware) formed in an integrated circuit (IC chip) or a computer via software. In the latter case, the computer includes: a recording medium in a computer-readable manner containing programs that implement the functions of the control device 60 and various data related to the work machine 1; an arithmetic circuit such as a CPU (Central Processing Unit) that executes commands of the program; and RAM (Random Access Memory) that displays the program and various data. Furthermore, the arithmetic circuit reads and executes the program from the recording medium, thereby realizing the functions of the control device 60.

[0093] Control devices 17L and 17R, which are held by the operator during operation, are connected to the control device 60. Control devices 17L and 17R are respectively located near the driver's seat 6. Control devices 17L and 17R each have a lever 17a and a position sensor 17b. The lever 17a can swing freely forward, backward, right, and left from the neutral position, and the position sensor 17b detects the amount of swing (operation amount) of the lever 17a from the neutral position in these directions.

[0094] For example, when the operator swings the operating lever 17a of the control device 17R forward or backward, the amount of swing is input to the control device 60. The boom control unit 61 (control device 60) energizes or demagnetizes the first solenoid 71D and the second solenoid 71E based on the obtained swing direction and amount of the operating lever 17a, thereby switching the boom control valve 71. In other words, the boom control unit 61 controls the swing of the boom 11.

[0095] Furthermore, when the operator swings the control lever 17a of the control device 17L forward or backward, the amount of swing is input to the control device 60. The stick control unit 62 (control device 60) energizes or demagnetizes the first solenoid 72D and the second solenoid 72E based on the obtained swing direction and amount of the control lever 17a, thereby switching the stick control valve 72. In other words, the stick control unit 62 controls the swing of the stick 12.

[0096] Furthermore, when the operator swings the operating lever 17a of the control device 17R to the left or right, the amount of swing is input to the control device 60. The bucket control unit 63 (control device 60) energizes or demagnetizes the first solenoid 73D and the second solenoid 73E based on the obtained swing direction and amount of the operating lever 17a, thereby switching the bucket control valve 73. In other words, the bucket control unit 63 controls the swing of the bucket 13.

[0097] The boom angle sensor 91, stick angle sensor 92, and bucket angle sensor (tool angle sensor) 93 are connected to the control device 60. The boom angle sensor 91 detects the swing angle θ2 (swing position) of the boom 11. The stick angle sensor 92 detects the swing angle θ3 (swing position) of the stick 12. The bucket angle sensor 93 detects the swing angle θ4 (swing position) of the bucket 13 relative to the top of the stick 12 about the pivot 57. In this embodiment, potentiometers are used as the boom angle sensor 91, stick angle sensor 92, and bucket angle sensor 93, but it is not limited to this. Other angle sensors can also be used, or the stroke (extension position) of the boom cylinder C2, stick cylinder C3, and bucket cylinder C4 can be detected, and the swing angles of the boom 11, stick 12, and bucket 13 can be calculated based on the detection results.

[0098] like Figure 10 As shown, the control device 60 has a boom loading limiter 64. (As shown) Figure 11 As shown, the stick loading restriction part 64 restricts the travel S1 of the stick loading direction D1 of the stick cylinder C3 so that the swing track M3 of the top part 58 of the bucket (working tool) 13 is separated from the boom cylinder C2 (or cylinder protector if a cylinder protector is provided) by a predetermined distance or more. This prevents interference (contact) between the top part 58 of the bucket 13 and the boom cylinder C2.

[0099] Figure 11 This indicates the changing state of the boom 11's swing position, the state of the stick 12 at the restricted position Y10 in the stick loading direction D1, and the state of the bucket 13 swinging from the bucket loading position Y1 to the bucket unloading position Y2. Specifically, the changing state of the boom 11's swing position indicates the state of the boom 11 changing from the raised position (highest raised position) 19 to the lowered position (lowest lowered position) 25, and the swing position Y5 indicates the intermediate position of the boom 11 between the raised position 19 and the lowered position 25. Outside the restricted release area of ​​the stroke S1 described later, the stroke S1 of the stick cylinder C3 in the stick loading direction D1 is restricted (stick loading restriction) to keep the swing track M3 separated from the boom cylinder C2 (cylinder protector) by a specified interval. Figure 11In the diagram, the dashed line R1 is the line tangent to the swing track M3 when the boom 11 swings between the highest raised position 19 and the lowest position 25 while the boom 12 is in the restricted position Y10.

[0100] like Figure 10 As shown, the control device 60 has a shovel loading restriction release unit 65. When performing a specific operation via the working device 4, the shovel loading restriction release unit 65 releases the stick shovel loading restriction to enable efficient operation. The shovel loading restriction release unit 65 releases the restriction on the stroke S1 of the stick cylinder C3, allowing the stick 12 to swing to the end of the stick shovel loading direction D1 within the swing range.

[0101] like Figure 10 As shown, the control device 60 includes a bucket loading restriction section (working tool loading restriction section) 66. When the restriction on the stroke S1 of the boom cylinder C3 is released by the loading restriction release section 65, the bucket loading restriction section 66 restricts the swing of the bucket 13 in the bucket loading direction D3, so that the swing track M3 of the top part 58 of the bucket 13 is separated from the boom cylinder C2 (or a cylinder protector if a cylinder protector is provided) by a predetermined distance or more. In other words, the bucket loading restriction section 66 restricts the stroke of the bucket cylinder C4 in the bucket loading direction D3, so that the swing track M3 of the top part 58 of the bucket 13 is separated from the boom cylinder C2 by a predetermined distance or more.

[0102] However, as for the work performed by the work machine 1, there is a so-called "basket work" in which the soil is scooped up by the bucket 13 using the front surface (scraper surface) of the scraper 7A of the bulldozer blade device 7.

[0103] like Figure 12 As shown, when the bending angle 27 of the boom 11 is increased (shallowed), in "shovel operation," compared to the conventional case where the boom bending angle is small (deep), the boom cylinder C2 and the top part 58 of the bucket 13 will approach the position where the top part 58 of the bucket 13 interferes with the boom cylinder C2. Conventionally, because the boom bending angle is small (deep), even in "shovel operation," the top part of the bucket will not interfere with the boom cylinder. However, in this embodiment, as described above, a stick loading restriction part 64 is provided to limit the stroke S1 of the stick loading direction D1 of the stick cylinder C3 by separating the swing track M3 of the top part 58 of the bucket 13 from the boom cylinder C2 by a predetermined interval or more. Therefore, even if the bending angle 27 of the boom 11 is increased, interference (contact) between the top part 58 of the bucket 13 and the boom cylinder C2 can be prevented by stick loading control.

[0104] In addition, when the limit of the stroke S1 of the boom cylinder C3 is released by the loading restriction release part 65, the swing of the bucket loading direction D3 of the bucket 13 is restricted by the bucket lowering restriction part 66, thereby preventing the top part 58 of the bucket 13 from interfering with (colliding with) the boom cylinder C2.

[0105] like Figure 3 , Figure 13 As shown, the boom base 11A is formed in a two-pronged manner with a pair of pivot support portions 11Aa extending from the connecting portion 11Ab. The pair of pivot support portions 11Aa are arranged to sandwich the first pivot support portion 23 of the swing bracket 10, and a space portion 51 is formed between the connecting portion 11Ab, the first pivot support portion 23, and the boom support shaft 35. Therefore, as Figure 13 As shown, the hydraulic hose 42 can pass through the space 51, and the hydraulic hose 42, which is disposed in front of the boom support shaft 35 from the lower part of the support bracket 9 through the interior of the swing bracket 10, can be disposed on the back side of the boom 11 through the space 51.

[0106] The work machine 1 of this embodiment includes: a machine body 2; a boom support (swing bracket 10) disposed in front of the machine body 2; a boom 11, including: a boom base 11A, pivotally supported on the boom support 10 via a boom support shaft 35; a boom tip 11B, pivotally supported on the stick 12 via a stick support shaft 43 so as to be able to swing; and a boom body 11C, which is the portion between the boom base 11A and the boom tip 11B and is bent at the middle portion 11Cc in the boom length direction, the boom 11 being able to swing up and down about the boom support shaft 35; and a boom cylinder C2, disposed on the front side of the boom 11, one end of which is pivotally supported on the front side of the boom body 11C via a first cylinder support shaft 37. On the other side, the boom 11 is pivotally supported on the boom support body 10 via the second cylinder support shaft 36. The boom 11 swings by extension and retraction. When the boom 11 swings to the highest raised position 19, the boom 11 is in the posture of the first part 11Ca between the middle part 11Cc and the boom base 11A extending upward from the boom base 11A toward the middle part 11Cc, and the second part 11Cb between the middle part 11Cc and the boom tip 11B extending in an inclined direction as it moves forward from the middle part 11Cc toward the top. The first straight line 26a, which is orthogonal to the stick support shaft 43 and the first cylinder support shaft 37 and extends downward compared to the first cylinder support shaft 37, passes through the front of the machine body 2.

[0107] Therefore, in the work machine 1 where the boom 11 is swung upward to its highest raised position 19, the first part 11Ca of the boom body 11C extends upward from the boom base 11A toward the middle part 11Cc, and the second part 11Cb of the boom body 11C bends in an inclined direction that moves forward from the middle part 11Cc toward the top. Because the first straight line 26a, configured to be orthogonal to the stick support shaft 43 and the first cylinder support shaft 37 and extending downward relative to the first cylinder support shaft 37, passes through the front of the machine body 2, the bending angle 27 of the boom 11 (the angle between the first part 11Ca and the second part 11Cb) is larger than before. This allows for a higher boom tip 11B when the boom 11 is in its highest raised position 19, and also reduces the weight of the boom 11.

[0108] In addition, the aircraft has a pilot's seat 6 mounted on the fuselage 2, and the boom 11 is configured such that the extension line of the back side 11Cb2 of the second part 11Cb at the highest raised position 19, that is, the first extension line 28a extending downward from the back side of the second part 11Cb, passes through the front of the pilot's seat 6.

[0109] As a result, since the bending angle 27 of the boom 11 increases, the height of the boom tip 11B when the boom 11 is in the highest raised position 19 can be increased, and the weight of the boom 11 can also be reduced.

[0110] In addition, the aircraft has a pilot's seat 6 mounted on the fuselage 2, and the boom 11 is configured such that the extension line 11Cb1 of the front of the second part 11Cb at the highest raised position 19, that is, the second extension line 28b extending downward from the front of the second part 11Cb, passes through the front of the pilot's seat 6.

[0111] As a result, since the bending angle 27 of the boom 11 increases, the height of the boom tip 11B when the boom is in the highest raised position 19 can be increased, and the weight of the boom 11 can also be reduced.

[0112] Furthermore, at the highest raised position 19, when the straight line orthogonal to the stick support shaft 43 and the boom support shaft 35 is designated as the second straight line 26b, the straight line orthogonal to the second straight line 26b and the first cylinder support shaft 37 (axis 37a) is designated as the third straight line 26c, the intersection of the second straight line 26b and the third straight line 26c is designated as the first intersection point 29a, the intersection of the third straight line 26c with the front of the boom body 11C is designated as the second intersection point 29b, and the intersection of the third straight line 26c with the back of the boom body 11C is designated as the third intersection point 29c, the first distance 31a between the first intersection point 29a and the second intersection point 29b is less than the second distance 31b between the second intersection point 29b and the third intersection point 29c.

[0113] As a result, since the bending angle 27 of the boom 11 increases, the height of the boom tip 11B when the boom is in the highest raised position 19 can be increased, and the weight of the boom 11 can also be reduced.

[0114] Furthermore, at the highest raised position 19, when the vertical line orthogonal to the stick support shaft 43 is designated as the fourth straight line 26d, the straight line orthogonal to the fourth straight line 26d and the first cylinder support shaft 37 is designated as the fifth straight line 26e, the intersection of the fourth straight line 26d and the fifth straight line 26e is designated as the fifth intersection point 29e, and the intersection of the fifth straight line 26e and the back of the boom body 11C is designated as the sixth intersection point 29f, the fifth distance 31e between the fifth intersection point 29e and the sixth intersection point 29f is less than the sixth distance 31f between the axis 43a of the stick support shaft 43 and the fifth intersection point 29e.

[0115] As a result, since the bending angle 27 of the boom 11 increases, the height of the boom tip 11B when the boom is in the highest raised position 19 can be increased, and the weight of the boom 11 can also be reduced.

[0116] Furthermore, at the highest raised position 19, when the vertical line orthogonal to the boom support shaft 35 (axis 35a) is set as the sixth straight line 26f, and the vertical line orthogonal to the second cylinder support shaft 36 (axis 36a) is set as the seventh straight line 26g, the seventh distance 31g between the fourth straight line 26d and the seventh straight line 26g is less than the eighth distance 31h between the sixth straight line 26f and the seventh straight line 26g.

[0117] As a result, since the bending angle 27 of the boom 11 increases, the height of the boom tip 11B when the boom is in the highest raised position 19 can be increased, and the weight of the boom 11 can also be reduced.

[0118] In addition, the sixth distance 31f is greater than the ninth distance 31i in the vertical direction between the fifth straight line 26e and the upper edge 11Ac of the side of the boom base 11A.

[0119] As a result, since the bending angle 27 of the boom 11 increases, the height of the boom tip 11B when the boom is in the highest raised position 19 can be increased, and the weight of the boom 11 can also be reduced.

[0120] In addition, the boom base 11A has a pivot support portion 11Aa that is pivotally supported by the boom support shaft 35, and a connecting portion 11Ab that is connected to the first portion 11Ca of the boom body portion 11C. When the boom 11 is swung to the highest raised position 19, the pivot support portion 11Aa extends in an inclined direction that moves backward from the boom support shaft 35 side upward, and the connecting portion 11Ab bends between the pivot support portion 11Aa and the connecting portion 11Ab in a manner that extends upward from the pivot support portion 11Aa.

[0121] This allows the boom 11 to descend fully to the downward swinging position 25.

[0122] In addition, the angle formed by the front face 11Ca1 of the first part 11Ca and the front face 11Cb1 of the second part 11Cb, i.e., the bending angle (first bending angle) 27, is greater than the angle formed by the front face 11Aa1 of the pivot support part 11Aa and the front face 11Ab1 of the connecting part 11Ab, i.e., the bending angle (second bending angle) 39.

[0123] Additionally, it includes: a working tool 13, which is pivotally supported on the stick 12 via a working tool support shaft 57, and can swing between the working tool loading position Y1 closest to the stick 12 and the working tool unloading position Y2 furthest from the stick 12 at the top end 58 by swinging around the working tool support shaft 57; a stick cylinder C3, which swings the stick 12 in the stick loading direction D1 close to the boom 11 and in the stick unloading direction D2 away from the boom 11; and a stick loading restriction part 64, which restricts the stroke S1 of the stick loading direction D1 of the stick cylinder C3 so that the swing track M3 of the top end 58 of the working tool 13 is separated from the boom cylinder C2 by a predetermined interval or more.

[0124] Therefore, even if the bending angle 27 of the boom 11 is made shallower, interference between the working tool 13 and the boom cylinder C2 can be avoided.

[0125] Additionally, it includes: a working tool 13, which is pivotally supported on the boom 12 via a working tool support shaft 57, and can swing between the working tool loading position Y1 closest to the boom 12 and the working tool unloading position Y2 furthest from the boom 12 at the top end 58 by swinging around the working tool support shaft 57; a working tool cylinder C4, which causes the working tool 13 to swing in the working tool loading direction D3 near the working tool loading position Y1 at the top end 58 and in the working tool unloading direction D4 near the working tool unloading position Y2 at the top end 58; and a working tool loading restriction part 66, which restricts the stroke of the working tool cylinder C4 in the working tool loading direction D3 so that the swing track M3 of the top end 58 of the working tool 13 is separated from the boom cylinder C2 by a predetermined interval or more.

[0126] Therefore, even if the bending angle 27 of the boom 11 is made shallower, interference between the working tool 13 and the boom cylinder C2 can be avoided.

[0127] The foregoing has described one embodiment of the present invention, but it should be considered that the embodiments disclosed herein are illustrative rather than limiting in all respects. The scope of the present invention is defined not by the foregoing description but by the claims, and includes all modifications within the meaning and scope of the claims.

[0128] Explanation of reference numerals in the attached figures:

[0129] 2. Body

[0130] 6. Driver's Seat

[0131] 9. Support bracket

[0132] 10. Boom support (swing bracket)

[0133] 10a Oscillation axis

[0134] 11. Boom

[0135] 11A Boom Base

[0136] 11Aa Pivot support section

[0137] 11Aa1 Front

[0138] 11Ab Connection Part

[0139] 11Ab1 Front

[0140] 11Ac upper edge

[0141] 11B Boom top section

[0142] 11C boom body

[0143] 11Ca First Part

[0144] 11Ca1 Front

[0145] 11Cb Second Part

[0146] 11Cb1 Front

[0147] 11Cb2 Back

[0148] 11Cc Middle section

[0149] 12 poles

[0150] 13. Work Tools

[0151] 19 Highest lifting position

[0152] 26a First straight line

[0153] 26b Second straight line

[0154] 26c Third straight line

[0155] 26d Fourth line

[0156] 26e Fifth line

[0157] 26f, the sixth straight line

[0158] 26g Seventh Line

[0159] 27. Bending angle (first bending angle)

[0160] 28a First Extension Line

[0161] 28b Second Extension Line

[0162] 29a First intersection point

[0163] 29b Second intersection point

[0164] 29c Third intersection point

[0165] 29d Fourth intersection point

[0166] 29e Fifth intersection point

[0167] 29f Sixth intersection point

[0168] 31a First Distance

[0169] 31b Second distance

[0170] 31c Third distance

[0171] 31d Fourth distance

[0172] 31e Fifth Distance

[0173] 31f Sixth Distance

[0174] 31g Seventh Distance

[0175] 31h Eighth Distance

[0176] 31i Ninth Distance

[0177] 35 boom support shaft

[0178] 36 Second cylinder support shaft

[0179] 37 First cylinder support shaft

[0180] 39. Bending angle (second bending angle)

[0181] 43. Bucket support shaft

[0182] 43a Axis

[0183] 57. Work tool support shaft

[0184] 58 Top section

[0185] 64. Stick Loading Limiting Section

[0186] 66. Loading and unloading restriction section for work tools

[0187] C2 boom cylinder

[0188] C3 boom cylinder

[0189] D1 Stick Loading Direction

[0190] D2 Bucket tilting direction

[0191] D3 Working Tool Loading Direction

[0192] C4 tool cylinder

[0193] M3 Swing Track

[0194] S1 Itinerary

[0195] Y1 Tool Loading Position

[0196] Y2 Tool Unloading Position

[0197] D4 Tool unloading direction

Claims

1. A type of work machine, wherein, have: Organism; The support bracket is configured to protrude further forward than the front surface of the body. The boom support is mounted on the support bracket in a manner that allows it to swing about a swing axis extending in the vertical direction. A boom, comprising: a boom base supported on a boom support body via a boom pivot; a boom tip supported on a stick pivot via a stick pivot to enable swinging; and a boom body portion, which is the portion between the boom base and the boom tip and is bent at the middle of the boom's length, the boom being capable of swinging up and down about the boom pivot; and A boom cylinder is disposed on the front side of the boom, with one end supported on the front side of the boom body via a first cylinder pivot, and the other end supported on the boom support via a second cylinder pivot. The boom swings by extending and retracting. The boom is configured such that, when it swings up and down about the boom support shaft, the angle formed by the front of the first portion between the middle part and the base of the boom and the front of the second portion between the middle part and the top part of the boom, i.e., the bending angle, does not change. Furthermore, when the boom swings to its highest lifting position, the boom becomes a first straight line that is orthogonal to the stick support shaft and the first cylinder support shaft and extends downwards from the first cylinder support shaft, passing behind the boom support body. The first portion extends upwards from the boom base toward the middle portion, and the second portion extends forwards in an inclined direction as it moves upwards from the middle portion. The first straight line passes in front of the front surface of the machine body.

2. The work machine according to claim 1, wherein, The work machine has a driver's seat mounted on the machine body. The boom is configured such that the extension line of the back of the second part at the highest lifting position, i.e., the first extension line extending downward from the back of the second part, passes in front of the driver's seat.

3. The work machine according to claim 1, wherein, The work machine has a driver's seat mounted on the machine body. The boom is configured such that the extension line of the front of the second part at the highest lifting position, that is, the second extension line extending downward from the front of the second part, passes through the front of the driver's seat.

4. The operating machine according to any one of claims 1 to 3, wherein, At the highest raised position, when a straight line orthogonal to and passing through the stick support shaft and the boom support shaft is designated as the second straight line, a straight line orthogonal to the second straight line and passing through the first cylinder support shaft is designated as the third straight line, the intersection of the second straight line and the third straight line is designated as the first intersection point, the intersection of the third straight line and the front of the boom body is designated as the second intersection point, and the intersection of the third straight line and the back of the boom body is designated as the third intersection point, the first distance between the first intersection point and the second intersection point is less than the second distance between the second intersection point and the third intersection point.

5. The work machine according to any one of claims 1 to 3, wherein, At the highest raised position, when the vertical line passing through the stick support shaft is designated as the fourth straight line, the straight line orthogonal to the fourth straight line and passing through the first cylinder support shaft is designated as the fifth straight line, the intersection of the fourth straight line and the fifth straight line is designated as the fifth intersection point, and the intersection of the fifth straight line and the back of the boom body is designated as the sixth intersection point, the fifth distance between the fifth intersection point and the sixth intersection point is less than the sixth distance between the axis of the stick support shaft and the fifth intersection point.

6. The work machine according to claim 5, wherein, At the highest raised position, when the vertical line passing through the boom support shaft is designated as the sixth straight line and the vertical line passing through the second cylinder support shaft is designated as the seventh straight line, the seventh distance between the fourth straight line and the seventh straight line is less than the eighth distance between the sixth straight line and the seventh straight line.

7. The work machine according to claim 5, wherein, The sixth distance is greater than the ninth distance in the vertical direction between the fifth straight line and the upper edge of the side of the boom base.

8. The work machine according to any one of claims 1 to 3, wherein, The boom base has a pivot support portion that is pivotally supported via the boom support shaft, and a connection portion that connects to the first portion of the boom body. When the boom is swung to the highest raised position, the pivot support portion extends in an inclined direction that moves rearward from the boom support shaft side upward, and the connection portion bends between the pivot support portion and the connection portion in a manner that extends upward from the pivot support portion.

9. The work machine according to claim 8, wherein, The first curvature angle formed by the front of the first part and the front of the second part is greater than the second curvature angle formed by the front of the pivot support part and the front of the connecting part.

10. The operating machine according to any one of claims 1 to 3, wherein, have: The working tool is supported on the stick via a working tool support shaft pivot. By swinging around the working tool support shaft, it can swing between the working tool loading position at the top closest to the stick and the working tool unloading position at the top furthest from the stick. A boom cylinder that causes the boom to swing in a boom loading direction close to the boom and in a boom unloading direction away from the boom; and The boom loading limiter restricts the travel of the boom cylinder in the boom loading direction so that the swing track of the top end of the working tool is separated from the boom cylinder by a predetermined interval or more.

11. The operating machine according to any one of claims 1 to 3, wherein, have: The working tool is supported on the stick via a working tool support shaft pivot. By swinging around the working tool support shaft, it can swing between the working tool loading position at the top closest to the stick and the working tool unloading position at the top furthest from the stick. The tool cylinder causes the tool to swing in the tool loading direction near the tool's top end and in the tool unloading direction near the tool's top end; and The tool loading restriction part limits the travel of the tool cylinder in the tool loading direction so that the swing track of the top part of the tool is separated from the boom cylinder by a predetermined interval or more.

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