Deep foundation excavator

Abstract

To keep a work posture low during excavation work and improve workability when performing maintenance of a rope supporting an excavation attachment.SOLUTION: A boom 12 of a work device 11 comprises a first boom member 13 having a base end 13D rotatably connected to an upper revolving body 3, and a second boom member 14 rotatably connected to a tip 13F of the first boom member 13. An arm cylinder 21 is provided between the second boom member 14 and an arm 15. A positioning cylinder 20 for rotating the second boom member 14 with respect to the first boom member 13 is provided between the first boom member 13 and the second boom member 14. The second boom member 14 rotates toward the rear side of the first boom member 13 by the positioning cylinder 20 about a connecting portion with the first boom member 13.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a deep foundation excavator suitable for use in excavating a shaft or the like. [Background technology]

[0002] At the construction sites of high-rise buildings today, the inverted construction method is used to simultaneously carry out above and below ground construction in order to shorten the construction period and to ensure stable underground construction even on soft ground. In this inverted construction method, the height equivalent to the second floor of the building is secured as the working space for excavating the shaft, but the presence of beams at the top limits the height of the excavation bucket above ground during work. Moreover, since the working space other than near the top of the shaft is narrow, even if a disassembled excavator is brought to the work site inside the building, it may be difficult to assemble it. For this reason, it is preferable to transport the excavator to the work site in an assembled state.

[0003] Conventionally, as a deep foundation excavator for excavating a shaft underground and lifting soil and sand, a telescopic clamshell equipped with a multi-stage telescopic arm and a clamshell bucket based on a hydraulic excavator body, or a mechanical clamshell equipped with a clamshell bucket based on a crawler crane, is known. However, it is difficult to introduce a telescopic clamshell into a site where a top-down construction method is used due to the height restrictions at the work site. In addition, a mechanical clamshell is transported to the work site in a disassembled state with the working equipment, including the crane boom, etc., so it is difficult to assemble the working equipment in a narrow work space inside a building.

[0004] In response to this, a high-lift vehicle has been proposed that is equipped with a telescopic arm supported horizontally via an arm support mechanism on an upper rotating body, and a bucket supported at the end of the telescopic arm via a rope so that it can be raised and lowered. With this high-lift vehicle, the telescopic arm is supported horizontally, making it possible to keep the working height low, and excavation work can be performed even at work sites with height restrictions, such as those using inverted driving methods (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-167170 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the high-lift vehicle described in Patent Document 1, the rope supporting the bucket is routed above the telescopic arm, so even when the telescopic arm is in the lowest position above the ground, the rope is located above the top of the cab. This means that maintenance work on the rope must be performed at a position higher than the top of the cab using a stepladder or the like, which creates a problem of poor workability.

[0007] Furthermore, in the high-lift vehicle according to Patent Document 1, the arm support mechanism that supports the telescopic arm on the upper rotating body is composed of a first link, an arm cylinder, a link cylinder, etc. Therefore, the telescopic arm cannot be directly attached to the upper rotating body of a hydraulic excavator via the arm support mechanism, and a high-lift vehicle cannot be manufactured using the upper rotating body of a normal hydraulic excavator, resulting in a problem of increased manufacturing costs.

[0008] The object of the present invention is to provide a deep foundation excavator that can keep the working posture low during excavation work and improves workability when performing maintenance on the rope supporting the excavation attachment. [Means for solving the problem]

[0009] The present invention relates to a deep foundation excavator comprising a self-propelled vehicle body and a working device provided on the vehicle body, the working device including a boom rotatably attached to the vehicle body, a boom cylinder provided between the vehicle body and the boom, an arm rotatably attached to the tip of the boom, an arm cylinder provided between the boom and the arm, and an excavation attachment supported by a rope that is reeled out from the arm. The boom includes a first boom member having a base end rotatably connected to the vehicle body, The base end A second boom member pivotally connected to the tip of the first boom member. And It is composed of The arm is provided at the tip of the second boom member, The arm cylinder is Note 2 A boom member is provided between the boom member and the arm, and one end of the boom member is connected to the back surface of the first boom member between the first boom member and the second boom member. , by shrinking operation The above Second Boom components On the rear side of the first boom member A positioning cylinder is provided to rotate the second boom member, and the second boom member is rotated by the positioning cylinder. 、 Centering on the connection part with the first boom member The tip of the second boom member is directed upward relative to the horizontal direction. It is characterized by rotating toward the rear side of the first boom member. Effect of the Invention

[0010] According to the present invention, for example, by rotating the second boom member toward the back side of the first boom member while the tip of the first boom member is facing downward, and rotating the arm so that it is horizontal to the ground, the height of the arm above the ground can be lowered. Therefore, the working posture during excavation work can be kept low. In addition, maintenance of the rope arranged on the arm to support the excavation attachment can be performed from the ground, improving the workability of this maintenance work. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a left side view showing a deep foundation excavator according to an embodiment of the present invention. [Diagram 2]This is a left side view showing the deep foundation excavator in the working position excavating a shaft. [Diagram 3] FIG. 2 is a left side view showing the deep foundation excavator in the maintenance position. [Figure 4] FIG. 2 is a left side view showing the deep foundation excavator in a transport position. [Diagram 5] FIG. 2 is a left side view showing a deep foundation excavator according to a comparative example. [Figure 6] FIG. 2 is a schematic diagram showing a working device of a deep foundation excavator according to the present embodiment and a working device according to a first modified example. [Figure 7] FIG. 11 is a plan view of a second modified example of the working device as seen from above the deep foundation excavator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of a deep foundation excavator according to the present invention will be described in detail with reference to Figures 1 to 4. In the embodiment, the traveling direction of the deep foundation excavator is the front-rear direction, and the direction perpendicular to the traveling direction is the left-right direction.

[0013] In Fig. 1, the deep foundation excavator 1 is manufactured based on, for example, a crawler-type hydraulic excavator. The deep foundation excavator 1 is composed of a self-propelled crawler-type lower traveling body 2, an upper rotating body 3 rotatably mounted on the lower traveling body 2, and a working device 11 provided on the upper rotating body 3. The lower traveling body 2 and the upper rotating body 3 constitute the vehicle body of the deep foundation excavator 1.

[0014] The upper rotating body 3 has a rotating frame 4 that is rotatably attached on the lower traveling body 2. The rotating frame 4 is a type that is applied to general hydraulic excavators, and is provided with left and right vertical plates at the middle in the left-right direction that face each other in the left-right direction and extend in the front-rear direction. The front end sides of these left and right vertical plates serve as left and right support brackets 4A (only the left side is shown) that support a first boom member 13 and a boom cylinder 19, which will be described later.

[0015] A cab 5 that defines the operator's compartment is provided on the front left side of the revolving frame 4. A driver's seat is provided inside the cab 5, and around the driver's seat are arranged a travel lever and pedal device that controls the travel operation of the lower traveling body 2, the rotation operation of the upper revolving body 3, and an operation lever device (none of which are shown) that controls the operation of the working equipment 11. A counterweight 6 that balances the weight with the working equipment 11 is provided on the rear end side of the revolving frame 4. An exterior cover 7 that houses a prime mover, a hydraulic pump, etc. (none of which are shown) is provided in front of the counterweight 6.

[0016] The working device 11 includes a boom 12 rotatably attached to the upper rotating body 3 (support bracket 4A of the rotating frame 4), an arm 15 rotatably attached to the tip of the boom 12, and a clamshell bucket 16 supported at the tip of the arm 15 via a lifting rope 17 and an opening / closing rope 18. Here, the boom 12 of the deep foundation excavator 1 according to this embodiment is composed of two boom members, a first boom member 13 and a second boom member 14.

[0017] The first boom member 13 is attached to the upper rotating body 3. The first boom member 13 is formed as a rectangular tube having a square cross section, with left and right side surfaces 13A facing each other at a fixed distance in the left-right direction, and a back surface 13B and a ventral surface 13C facing each other in the up-down direction across the left and right side surfaces 13A. The back surface 13B of the first boom member 13 becomes the upper surface when the first boom member 13 is extended in the front-to-rear direction (the state shown in FIG. 3), and the ventral surface 13C of the first boom member 13 becomes the lower surface when the first boom member 13 is extended in the front-to-rear direction.

[0018] A base end 13D of the first boom member 13 is rotatably connected to a support bracket 4A of the revolving frame 4 by means of a pin 13E. A base end 14D of the second boom member 14 is rotatably connected to a tip end 13F of the first boom member 13. A first bracket 13G protrudes from a back surface 13B of the first boom member 13 at a position close to the base end 13D, and the bottom side of a positioning cylinder 20, which will be described later, is attached to this first bracket 13G.

[0019] The second boom member 14 is rotatably connected to the tip 13F of the first boom member 13. The second boom member 14 is formed as a rectangular tube having a square cross section, with left and right side surfaces 14A facing each other at a fixed distance in the left-right direction, and a back surface 14B and a ventral surface 14C facing each other in the up-down direction across the left and right side surfaces 14A. The back surface 14B of the second boom member 14 becomes the upper surface when the second boom member 14 is extended in the front-rear direction (the state shown in FIG. 3), and the ventral surface 14C of the second boom member 14 becomes the lower surface when the second boom member 14 is extended in the front-rear direction.

[0020] The base end 14D of the second boom member 14 is rotatably connected to the tip 13F of the first boom member 13 by using a pin 14E. An arm 15 is rotatably connected to the tip 14F of the second boom member 14. A second bracket 14G protrudes from the back surface 14B of the second boom member 14. The second bracket 14G is disposed at a position closer to the connection side between the first boom member 13 and the second boom member 14 (the base end 14D side of the second boom member 14) than the center of the length direction of the second boom member 14, and the rod side of the positioning cylinder 20 is attached to the second bracket 14G. A third bracket 14H protrudes from the ventral surface 14C of the second boom member 14 on the base end 14D side. The bottom side of an arm cylinder 21 described later is attached to the third bracket 14H.

[0021] The arm 15 is rotatably attached to a tip 14F of a second boom member 14 constituting the boom 12. The arm 15 is formed as a long rectangular cylinder having a rectangular cross section, with left and right side surfaces 15A facing each other at a fixed distance in the left-right direction, and a back surface 15B and a ventral surface 15C facing each other in the up-down direction across the left and right side surfaces 15A. The back surface 15B of the arm 15 becomes the upper surface when the arm 15 is extended in the front-rear direction (the state shown in FIG. 2), and the ventral surface 15C of the arm 15 becomes the lower surface when the arm 15 is extended in the front-rear direction.

[0022] A boom bracket 15D and a cylinder bracket 15E are provided adjacent to each other in the length direction and protrude from the abdominal surface 15C of the arm 15. A tip end 14F of the second boom member 14 is rotatably connected to the boom bracket 15D using a pin 15F. The rod side of the arm cylinder 21 is pin-connected to the cylinder bracket 15E.

[0023] Here, the arm 15 is provided with a bucket lifting device (not shown) that uses a lifting rope 17 to lift and lower the clamshell bucket 16 in the vertical direction, and a bucket opening and closing device (not shown) that uses an opening and closing rope 18 to open and close the clamshell bucket 16. A guide sheave (not shown) that guides the lifting rope 17 and the opening and closing rope 18 downward is provided at a tip 15G of the arm 15.

[0024] The clamshell bucket 16 as an excavation attachment is supported by a lifting rope 17 and an opening / closing rope 18 that are reeled out from the tip 15G of the arm 15. The clamshell bucket 16 has a bucket support part 16A, a pair of buckets 16B that are provided on the lower side of the bucket support part 16A so as to be openable and closable, a connecting bracket 16C to which the pair of buckets 16B are rotatably connected, and a pair of opening / closing arms 16D that connect between the bucket support part 16A and the pair of buckets 16B. A plurality of upper sheaves 16E are provided on the bucket support part 16A, and a plurality of lower sheaves 16F that face the upper sheaves 16E in the vertical direction are provided on the connecting bracket 16C.

[0025] One end of a lifting rope 17 is fixed to the bucket support portion 16A of the clamshell bucket 16, and the other end of the lifting rope 17 is fixed to the arm 15. The bucket lifting device lifts and lowers the clamshell bucket 16 by changing the length of the lifting rope 17 extending from the tip 15G of the arm 15 to the clamshell bucket 16.

[0026] An opening / closing rope 18 is wound around the upper sheave 16E and the lower sheave 16F of the clamshell bucket 16. One end of the opening / closing rope 18 is fixed to the bucket support portion 16A of the clamshell bucket 16, and the other end of the opening / closing rope 18 is fixed to the arm 15. The bucket opening / closing device opens and closes the clamshell bucket 16 by changing the length of the opening / closing rope 18 extending from the tip 15G of the arm 15 to the clamshell bucket 16.

[0027] The boom cylinder 19 is provided between the upper rotating body 3 and the first boom member 13 of the boom 12. The boom cylinders 19 are arranged on both the left and right sides of the first boom member 13 (only the left side is shown), and rotate the boom 12 relative to the upper rotating body 3. Specifically, the bottom side of the boom cylinder 19 is rotatably connected to the support bracket 4A of the revolving frame 4 by a pin. The rod side of the boom cylinder 19 is rotatably connected to the side surface 13A of the first boom member 13 by a pin. Therefore, the first boom member 13 rotates (elevates and lowers) in the vertical direction around the connection part with the revolving frame 4 (support bracket 4A) by extending and retracting the boom cylinder 19.

[0028] One positioning cylinder 20 is provided between the first boom member 13 and the second boom member 14, and rotates the second boom member 14 relative to the first boom member 13. Specifically, the bottom side of the positioning cylinder 20 is rotatably connected by a pin to a first bracket 13G protruding from the back surface 13B of the first boom member 13. The rod side of the positioning cylinder 20 is rotatably connected by a pin to a second bracket 14G protruding from the back surface 14B of the second boom member 14.

[0029] As a result, when the positioning cylinder 20 is fully extended, the second boom member 14 opens to an angle of nearly 180° relative to the first boom member 13, as shown in Fig. 3. On the other hand, by contracting the positioning cylinder 20 from the state shown in Fig. 3, the second boom member 14 is configured to rotate toward the back surface 13B of the first boom member 13 around the connecting portion (pin 14E) with the first boom member 13, as shown in Figs. 1 and 2.

[0030] The arm cylinder 21 is provided between the arm 15 and the second boom member 14, which is a boom member attached to the arm 15, and rotates the arm 15 relative to the second boom member 14. Specifically, the bottom side of the arm cylinder 21 is rotatably connected by a pin to a third bracket 14H protruding from the abdominal surface 14C of the second boom member 14. The rod side of the arm cylinder 21 is rotatably connected by a pin to a cylinder bracket 15E protruding from the abdominal surface 15C of the arm 15.

[0031] Therefore, by extending or retracting the arm cylinder 21, the arm 15 rotates about the connection part (pin 15F) with the second boom member 14. This allows the height of the tip 15G of the arm 15 to be appropriately changed depending on the work site. When the working implement 11 is in the working posture shown in Fig. 2, the arm 15 is held at a low position, approximately horizontal to the ground, and the clamshell bucket 16 supported on the tip 15G side of the arm 15 can be positioned slightly above the bed 101A of the dump truck 101.

[0032] 3, the positioning cylinder 20 is fully extended and the arm cylinder 21 is fully contracted, causing the arm 15 to rotate half a turn about the connection part (pin 15F) with the second boom member 14. As a result, the back surface 15B of the arm 15 faces the ground with a small gap between them, and the entire arm 15 can be held at a position lower than the upper rotating body 3.

[0033] Furthermore, when the working implement 11 is in the transportation posture shown in Fig. 4, the positioning cylinder 20 is contracted to the minimum and the arm cylinder 21 is extended, so that the tip 14F of the second boom member 14 comes closest to the back surface 13B of the first boom member 13. At this time, a straight line connecting the center of the pin 13E which is the connection part between the first boom member 13 and the upper rotating body 3 and the center of the pin 14E which is the connection part between the first boom member 13 and the second boom member 14 is set as a first reference line 22, and a straight line connecting the center of the pin 14E which is the connection part between the first boom member 13 and the second boom member 14 and the center of the pin 15F which is the connection part between the second boom member 14 and the arm 15 is set as a second reference line 23. When the working implement 11 is in the transportation posture, the angle θ formed by the first reference line 22 and the second reference line 23 is set to be less than 90 degrees (θ<90°).

[0034] This allows the tip 15G of the arm 15 connected to the second boom member 14 to be pulled toward the upper rotating body 3. Therefore, the working device 11 can be moved to a compact transportation posture in which the vehicle body and the clamshell bucket 16 are stored within the length dimension of the arm 15, and when the deep foundation excavator 1 is loaded onto the bed 102A of the trailer 102, the length during transportation (total length during transportation) can be kept within the length restrictions imposed by the Road Traffic Act and the like, improving the workability of the transportation work.

[0035] Next, the reason why the arm cylinder 21 is provided between the abdominal surface 14C of the second boom member 14 and the abdominal surface 15C of the arm 15 will be explained.

[0036] That is, if an arm cylinder is provided between the back surface 14B of the second boom member 14 and the abdominal surface 15C of the arm 15, it is necessary to avoid interference between the arm cylinder and the second bracket 14G protruding from the back surface 14B of the second boom member 14. This reduces the space X formed between the back surface 14B of the second boom member 14 and the abdominal surface 15C of the arm 15, making it impossible to place an arm cylinder having a sufficient stroke in this space X. On the other hand, if the length of the second boom member is increased to increase the space X, the overall size of the working mechanism 11 will increase.

[0037] In contrast, in the deep foundation excavator 1 according to this embodiment, the arm cylinder 21 is provided between the ventral surface 14C of the second boom member 14 and the ventral surface 15C of the arm 15. This allows the arm cylinder 21 to be arranged with a large degree of freedom in space Y which is sufficiently large compared to space X in Fig. 4. This allows the overall length of the second boom member 14 to be reduced, and for example, when the working implement 11 is loaded on the platform 102A of the trailer 102 in a transport posture, the transport height can be made as low as possible.

[0038] The deep foundation excavator 1 according to this embodiment has the above-mentioned configuration, and when excavating a shaft using the deep foundation excavator 1, the operator gets into the cab 5 and drives the deep foundation excavator 1 to the work site by operating a travel lever / pedal device (not shown). Next, the operator operates an operating lever device (not shown) to extend and retract the boom cylinder 19, the positioning cylinder 20, and the arm cylinder 21. As a result, the working device 11 assumes a working posture in which the arm 15 is positioned above the second boom member 14 with the tip 13F of the first boom member 13 facing upward relative to the horizontal direction, as shown in Figures 1 and 2, etc.

[0039] At this time, the angle of the arm 15 with respect to the ground can be appropriately set by adjusting the extension amount of the positioning cylinder 20, etc. Therefore, for example, when performing excavation work inside a building where the working height is limited, the working posture can be changed by extending the positioning cylinder 20 so that the arm 15 is horizontal with the ground, and the working height of the deep foundation excavator 1 can be lowered.

[0040] On the other hand, at a work site where the working radius (the distance from the center of rotation of the upper rotating body 3 to the clamshell bucket 16) is limited, the positioning cylinder 20 is contracted to tilt the arm 15 so that the tip 15G faces upward relative to the horizontal direction relative to the ground. This allows the clamshell bucket 16 suspended from the tip 15G of the arm 15 to be brought closer to the upper rotating body 3, thereby reducing the working radius.

[0041] After determining the working posture of the working device 11 according to the work site, the operator uses the operating lever device to rotate the upper rotating body 3 and move the clamshell bucket 16 to above the shaft to be excavated. Next, the operator uses the bucket lifting device to lower the clamshell bucket 16 into the shaft, and when it reaches a position, for example, about 3 m above the bottom of the hole, opens the bucket 16B using the bucket opening and closing device. In this state, the clamshell bucket 16 is lowered again to land on the bottom of the hole, and after it sinks into the ground by its own weight, the bucket 16B is closed, thereby excavating the soil and retaining it in the bucket 16B. Then, the clamshell bucket 16 is raised above the shaft by the bucket lifting device, and the upper rotating body 3 is rotated.

[0042] In this way, after the clamshell bucket 16 is moved onto the bed 101A of the dump truck 101, the bucket 16B is opened and the soil is dumped. In this series of excavation operations, the working implement 11 maintains its initial working posture, so there is no need to change the strokes of the boom cylinder 19, the positioning cylinder 20, and the arm cylinder 21. As a result, the operator can concentrate on lifting and lowering and opening and closing the clamshell bucket 16 using the bucket lifting device and the bucket opening and closing device, and on rotating the upper rotating body 3, thereby improving the workability of the excavation operation.

[0043] In this way, in the deep foundation excavator 1 according to this embodiment, the second boom member 14 rotates toward the back surface 13B side of the first boom member 13 around the connecting part (pin 14E) with the first boom member 13 by the positioning cylinder 20. Therefore, by contracting the boom cylinder 19 and extending the positioning cylinder 20, the working posture of the working device 11 can be changed so that the arm 15 is horizontal to the ground, and the working height of the deep foundation excavator 1 can be lowered. As a result, even at work sites where the working height is limited, such as construction work sites using the upside-down construction method, work sites in urban areas where obstacles exist in the air, and work sites under bridges, excavation work can be performed smoothly using the deep foundation excavator 1.

[0044] In addition, the boom cylinder 19, the positioning cylinder 20, and the arm cylinder 21 can be appropriately extended and retracted to change the angle of the arm 15 relative to the ground, thereby changing the distance between the clamshell bucket 16 supported on the tip 15G side of the arm 15 and the upper rotating body 3. As a result, the working radius of the deep foundation excavator 1 can be reduced, and excavation work can be smoothly performed using the deep foundation excavator 1 even in a narrow work site, such as the inside of a building.

[0045] Furthermore, after the working posture of the working implement 11 is determined according to the work site, there is no need to change the strokes of the boom cylinder 19, the positioning cylinder 20, and the arm cylinder 21. As a result, during shaft excavation work, the operator can concentrate on lifting and opening / closing the clamshell bucket 16 and rotating the upper rotating body 3, improving the workability of the excavation work.

[0046] Moreover, the upper rotating body 3 of the deep foundation excavator 1 uses as its base a rotating frame 4 that is widely used in hydraulic excavators, and a base end 13D of the first boom member 13 is connected to a support bracket 4A provided on this rotating frame 4 using a pin 13E, and the bottom side of the boom cylinder 19 is also pin-connected. Therefore, the working mechanism 11 can be reassembled by utilizing a versatile rotating frame 4 mounted on other hydraulic excavators.

[0047] Next, when the deep foundation excavator 1 is transported to another work site, as shown in Fig. 4, the deep foundation excavator 1 is loaded onto the loading platform 102A of the trailer 102 with the working device 11 shifted to the transport posture. That is, with the clamshell bucket 16 raised to the tip 15G side of the arm 15 by the bucket lifting device, the boom cylinder 19 and the positioning cylinder 20 are contracted and the arm cylinder 21 is extended. In this way, the working device 11 is in a transport posture in which the boom cylinder 19 is contracted to place the tip 13F of the first boom member 13 at the lowest position where the height above the ground is minimum, and the tip 14F of the second boom member 14 is directed upward relative to the horizontal direction, with the arm 15 positioned above the second boom member 14.

[0048] In this manner, by rotating (bending) the second boom member 14 toward the back surface 13B of the first boom member 13 about the pin 14E, the working mechanism 11 can be quickly and easily moved to the transport posture without disassembling the first boom member 13 and the second boom member 14. Then, with the working mechanism 11 in the transport posture, the clamshell bucket 16 supported on the tip end 15G side of the arm 15 is placed on the carrier 102A, whereby the deep foundation excavator 1 can be transported by the trailer 102.

[0049] In the transportation posture of the working device 11, an angle θ formed by a first reference line 22 connecting the connection part (pin 13E) between the first boom member 13 and the upper rotating body 3 and the connection part (pin 14E) between the first boom member 13 and the second boom member 14 and a second reference line 23 connecting the connection part (pin 14E) between the first boom member 13 and the second boom member 14 and the connection part (pin 15F) between the second boom member 14 and the arm 15 is less than 90 degrees (θ<90°). As a result, the tip 15G of the arm 15 connected to the second boom member 14 can be pulled toward the upper rotating body 3, and the transportation length (total length during transportation) of the deep foundation excavator 1 loaded on the trailer 102 can be reduced.

[0050] In addition, the arm cylinder 21 is provided between the ventral surface 14C of the second boom member 14 and the ventral surface 15C of the arm 15. This allows the arm cylinder 21 to be arranged with a large degree of freedom in the space Y, which is sufficiently large compared to the space X in FIG. 4. As a result, the overall length of the second boom member 14 can be reduced. As a result, when the deep foundation excavator 1 is loaded on the loading platform 102A of the trailer 102 in the transport posture, the transport height (total height during transport) can be reduced. Thus, by shifting the working device 11 to the transport posture, the overall length and total height during transport of the deep foundation excavator 1 can be kept within the limits imposed by the Road Traffic Act and the like, and the workability of the transport work can be improved.

[0051] Furthermore, when the working mechanism 11 has shifted to the transport posture, the first bracket 13G of the first boom member 13 to which one end of the positioning cylinder 20 is pin-connected, the second bracket 14G of the second boom member 14 to which the other end of the positioning cylinder 20 is pin-connected, and the third bracket 14H of the second boom member 14 to which one end of the arm cylinder 21 is pin-connected do not protrude downward below the lower running body 2 of the deep foundation excavator 1. Therefore, the first bracket 13G, the second bracket 14G, the third bracket 14H, or the positioning cylinder 20 and the arm cylinder 21 can be prevented from being damaged during transportation of the deep foundation excavator 1.

[0052] Here, as a comparative example to the deep foundation excavator 1 according to this embodiment, a case where a deep foundation excavator equipped with an integrated boom that does not have a split structure is transported will be described with reference to FIG.

[0053] In FIG. 5, the deep foundation excavator 103 according to the comparative example has a vehicle body formed by a lower travel unit 104 and an upper rotating unit 105, and the upper rotating unit 105 is provided with a working device 106. The working device 106 is configured to include an integrated boom 107 whose base end is connected to the upper rotating unit 105, an arm 108 connected to the tip of the boom 107, a clamshell bucket 109 suspended from the tip of the arm 108, a boom cylinder 110, and an arm cylinder 111. Here, when the deep foundation excavator 103 according to the comparative example is loaded onto a trailer and transported, the working device 106 is moved from the working position shown by the solid line to the position shown by the two-dot chain line, and the overall height of the deep foundation excavator 103 during transportation is lowered. That is, the arm cylinder 111 is extended to invert the back surface and the ventral surface of the arm 108, and the boom cylinder 110 is contracted to bring the tip of the boom 107 closer to the ground.

[0054] In this state, the entire arm 108 is disposed in front of the upper rotating body 105, so that the overall length L from the rear end of the upper rotating body 105 to the front end of the arm 108 during transportation becomes large, and there is a risk that it will not be possible to keep it within the limits imposed by the Road Traffic Act, etc. For this reason, for example, it becomes necessary to transport the arm 108 in a state in which it is detached from the boom 107 to the work site, and then to attach the arm 108 to the boom 107 at the work site, which is a complicated task, and this reduces the workability when transporting the deep foundation excavator 103.

[0055] In contrast, in the deep foundation excavator 1 according to this embodiment, the angle θ between the first reference line 22 and the second reference line 23 can be set to less than 90 degrees by rotating the second boom member 14 toward the back surface 13B of the first boom member 13 around the connecting portion (pin 14E) with the first boom member 13. This allows the tip 15G of the arm 15 connected to the second boom member 14 to be drawn toward the upper rotating body 3, and the overall length of the deep foundation excavator 1 during transportation can be reduced. In addition, the arm cylinder 21 can be provided between the ventral surface 14C of the second boom member 14 and the ventral surface 15C of the arm 15, thereby reducing the overall length of the second boom member 14. This allows the overall height of the deep foundation excavator 1 during transportation to be reduced. Thus, by shifting the working device 11 to the transportation posture, the overall length and overall height of the deep foundation excavator 1 during transportation can be kept within the limits imposed by the Road Traffic Act and the like.

[0056] Next, a case will be described where the working device 11 is shifted to the maintenance position. The working device 11 shifts to the maintenance position shown in Fig. 3 when inspecting and replacing the lifting ropes 17 and the opening / closing ropes 18 that support the clamshell bucket 16, and when greasing the guide sheaves (not shown) that guide the lifting ropes 17 and the opening / closing ropes 18.

[0057] When the working device 11 is moved to the maintenance posture, the boom cylinder 19 and the arm cylinder 21 are contracted and the positioning cylinder 20 is extended. As the arm cylinder 21 is contracted and the positioning cylinder 20 is extended, the arm 15 rotates about the connecting portion (pin 15F) with the second boom member 14, and the back surface 15B and the ventral surface 15C are inverted so that the back surface 15B faces downward and faces the ground. In this state, the boom cylinder 19 is contracted, so that the back surface 15B of the arm 15 approaches the ground. As a result, the deep foundation excavator 1 is in a maintenance posture in which the tip 14F of the second boom member 14 faces downward relative to the horizontal direction and the arm 15 is disposed below the second boom member 14 with the back surface 15B of the arm 15 facing the ground.

[0058] When the working device 11 is in the maintenance position, the arm 15 can be held in a position substantially parallel to the ground at a position lower than the upper rotating body 3. Therefore, maintenance work such as inspection, replacement and greasing of the lifting ropes 17 and the opening / closing ropes 18 can be performed on the ground without using a stepladder or the like, improving workability.

[0059] In this case, a first bracket 13G to which one end of the positioning cylinder 20 is connected is provided on the back surface 13B of the first boom member 13, and a second bracket 14G to which the other end of the positioning cylinder 20 is connected is provided on the back surface 14B of the second boom member 14, located closer to the connecting portion (pin 14E) between the first boom member 13 and the second boom member 14 than the intermediate portion in the longitudinal direction of the second boom member 14. This makes it possible to make the stroke of the positioning cylinder 20 for shifting the working implement 11 between the working position (the position in FIG. 2) and the maintenance position (the position in FIG. 3) as small as possible. As a result, the overall length of the positioning cylinder 20 can be reduced, and the working implement 11 can be made smaller in size.

[0060] Thus, in the deep foundation excavator 1 according to this embodiment, the boom 12 of the working mechanism 11 is composed of a first boom member 13 having a base end 13D rotatably connected to the upper rotating body 3, and a second boom member 14 rotatably connected to the tip 13F of the first boom member 13, an arm cylinder 21 is provided between the second boom member 14 and the arm 15, and a positioning cylinder 20 is provided between the first boom member 13 and the second boom member 14, having one end connected to the back of the first boom member 13 and the other end connected to the back of the second boom member 14 for rotating the second boom member 14 relative to the first boom member 13, and the second boom member 14 rotates toward the back side of the first boom member 13 around the connection part (pin 14E) with the first boom member 13 by the positioning cylinder 20.

[0061] According to this configuration, the second boom member 14 rotates toward the back surface 13B of the first boom member 13 around the connecting portion (pin 14E) with the first boom member 13, so that the working posture can be changed so that the arm 15 is horizontal to the ground. This allows the working height of the deep foundation excavator 1 to be lowered, and excavation work can be smoothly performed using the deep foundation excavator 1 even at a work site where the working height is limited. In addition, the second boom member 14 rotates toward the back surface 13B of the first boom member 13, so that the tip 15G of the arm 15 connected to the second boom member 14 can be pulled toward the upper rotating body 3. As a result, the overall height and overall length during transportation of the deep foundation excavator 1 can be reduced, and the workability of the deep foundation excavator 1 during transportation can be improved.

[0062] In the embodiment, the base end 14D of the second boom member 14 is rotatably connected to the tip 13F of the first boom member 13 and the tip 14F is rotatably connected to the arm 15, and the arm cylinder 21 has one end connected to the ventral surface 14C of the second boom member 14 and the other end connected to the ventral surface 15C of the arm 15. With this configuration, the arm cylinder 21 can be arranged with a large degree of freedom in a large space formed on the ventral surface 14C side of the second boom member 14. As a result, the overall length of the second boom member 14 can be reduced, and the overall height during transportation of the deep foundation excavator 1 when the working mechanism 11 is in the transportation posture can be reduced.

[0063] In the embodiment, the working apparatus 11 changes to a working posture in which the arm 15 is disposed above the second boom member 14 with the tip of the first boom member 13 facing upward relative to the horizontal direction, a maintenance posture in which the arm 15 is disposed below the second boom member 14 with the tip 14F of the second boom member 14 facing downward relative to the horizontal direction and the back surface 15B of the arm 15 facing the ground, and a transport posture in which the tip 13F of the first boom member 13 is at the bottom and the tip 14F of the second boom member 14 facing upward relative to the horizontal direction and the arm 15 is disposed above the second boom member 14, according to the extension and contraction of the boom cylinder 19, the positioning cylinder 20, and the arm cylinder 21. With this configuration, the working apparatus 11 can be quickly and easily moved to the working posture, transport posture, and maintenance posture by simply extending and contracting the boom cylinder 19, the positioning cylinder 20, and the arm cylinder 21 without disassembling the working apparatus 11.

[0064] In the embodiment, if a straight line connecting the connection part (pin 13E) between the upper rotating body 3 and the first boom member 13 and the connection part (pin 14E) between the first boom member 13 and the second boom member 14 is defined as a first reference line 22, and a straight line connecting the connection part (pin 14E) between the first boom member 13 and the second boom member 14 and the connection part (pin 15F) between the second boom member 14 and the arm 15 is defined as a second reference line 23, when the working device 11 is in the transportation posture, the angle formed by the first reference line 22 and the second reference line 23 is less than 90 degrees. According to this configuration, the tip 15G of the arm 15 connected to the second boom member 14 can be pulled toward the upper rotating body 3, and the transportation length (total length during transportation) of the deep foundation excavator 1 loaded on the trailer 102 can be reduced.

[0065] In the embodiment, a first bracket 13G to which one end of the positioning cylinder 20 is connected is provided on the back surface 13B of the first boom member 13, and a second bracket 14G to which the other end of the positioning cylinder 20 is connected is provided on the back surface 14B of the second boom member 14, located closer to the connecting portion (pin 14E) between the first boom member 13 and the second boom member 14 than the intermediate portion in the longitudinal direction of the second boom member 14. With this configuration, the stroke of the positioning cylinder 20 for shifting the working implement 11 between the working posture and the maintenance posture can be made as small as possible, and the overall length of the positioning cylinder 20 can be reduced, thereby making it possible to miniaturize the working implement 11 as a whole.

[0066] In addition, as conceptually shown in Fig. 6(A), the deep foundation excavator 1 according to the embodiment illustrates a case in which the boom 12 of the working mechanism 11 is configured by two members, a first boom member 13 and a second boom member 14. However, the present invention is not limited to this, and may be configured, for example, as in the working mechanism 32 of the deep foundation excavator 31 according to the first modified example shown in Fig. 6(B). In this case, the working mechanism 32 of the deep foundation excavator 31 according to the first modified example includes a boom 33, an arm 34, and a clamshell bucket 35, and the boom 33 is configured by three members, a first boom member 33A, a second boom member 33B, and a third boom member 33C.

[0067] In this way, the deep foundation excavator 31 according to the first modification has the third boom member 33C interposed between the second boom member 33B and the arm 34, so that the clamshell bucket 35 suspended from the tip of the arm 34 can be brought closer to the vehicle body by an additional distance A compared to the deep foundation excavator 1 according to this embodiment. In this way, the degree of freedom of the working posture of the working device 32 is increased and the working range is expanded, so that the deep foundation excavator 31 can be used at various work sites.

[0068] Moreover, the deep foundation excavator 1 according to the embodiment is exemplified by a case in which one positioning cylinder 20 is provided between the first boom member 13 and the second boom member 14. However, the present invention is not limited to this, and may be configured, for example, as a deep foundation excavator 41 according to a second modified example shown in FIG.

[0069] The deep foundation excavator 41 according to the second modification is composed of a vehicle body consisting of a lower traveling body 2 and an upper rotating body 3, and a working device 42 provided on the upper rotating body 3, similar to the deep foundation excavator 1 according to the embodiment, and the working device 42 is composed of the first boom member 13, the second boom member 14, the arm 15, the bucket, the boom cylinder 19, the arm cylinder 21, etc. However, between the back surface 13B of the first boom member 13 and the back surface 14B of the second boom member 14, two positioning cylinders 43 are provided adjacent to each other in the left-right direction. That is, the bottom sides of the two positioning cylinders 43 are pin-connected to the first bracket 13G protruding from the back surface 13B of the first boom member 13, and the rod sides are pin-connected to the second bracket 14G protruding from the back surface 14B of the second boom member 14.

[0070] Here, during excavation work by the deep foundation excavator 1 according to the embodiment, hydraulic pressure is maintained in the rod-side oil chamber of the positioning cylinder 20, so if the bucket capacity (bucket capacity) is increased, there is a possibility that one positioning cylinder 20 will not have enough power. In response to this, it is conceivable to maintain hydraulic pressure regardless of the increase in bucket capacity by increasing the cylinder diameter of the positioning cylinder 20. However, by increasing the cylinder diameter, the overall length and stroke length of the positioning cylinder 20 increase, making it difficult to arrange the positioning cylinder 20 in an optimal position between the first boom member 13 and the second boom member 14.

[0071] For this reason, the deep foundation excavator 41 according to the second modification is configured to have two positioning cylinders 43 arranged in parallel between the first boom member 13 and the second boom member 14. With this configuration, hydraulic pressure can be maintained by the two positioning cylinders 43 regardless of an increase in bucket capacity. As a result, buckets with different specifications can be selected from a wide range according to the work site, and the deep foundation excavator 41 can be used in various excavation work situations. [Explanation of symbols]

[0072] 1,31,41 Deep foundation excavator 2 Undercarriage (car body) 3 Upper rotating body (car body) 11,32,42 Working equipment 12,33 Boom 13,33A First boom member 13D,14D proximal end 13F,14F tip 13G First bracket 14,33B Second boom member 14G 2nd bracket 13B,14B,15B Back 13C,14C,15C ventral surface 15,34 Arm 16,35 Clamshell bucket (digging attachment) 19 Boom cylinder 20,43 Positioning cylinder 21 Arm Cylinder 22 First Reference Line 23 Second Reference Line

Claims

1. The vehicle comprises a self-propelled vehicle body and a working device provided on the vehicle body, The working device is a deep foundation excavator including a boom rotatably attached to the vehicle body, a boom cylinder provided between the vehicle body and the boom, an arm rotatably attached to the tip of the boom, an arm cylinder provided between the boom and the arm, and an excavation attachment supported by a rope that is reeled out from the arm. The boom is composed of a first boom member having a base end rotatably connected to the vehicle body and a second boom member having a base end rotatably connected to a tip end of the first boom member, The arm is provided at a tip of the second boom member, the arm cylinder is provided between the second boom member and the arm, a positioning cylinder is provided between the first boom member and the second boom member, the positioning cylinder having one end connected to the back surface of the first boom member and the other end connected to the back surface of the second boom member, and configured to rotate the second boom member toward the back surface of the first boom member by a contracting operation; A deep foundation excavator characterized in that the second boom member rotates around the connection point with the first boom member by the positioning cylinder, with the tip of the second boom member rotating upward relative to the horizontal direction toward the rear side of the first boom member.

2. A deep foundation excavator as described in Claim 1, characterized in that the arm cylinder is configured such that one end is connected to the ventral surface of the second boom member and the other end is connected to the ventral surface of the arm.

3. The working device is configured to: a working posture in which the arm is disposed above the second boom member with a tip end of the first boom member facing upward with respect to a horizontal direction; a maintenance posture in which the arm is disposed below the second boom member with a tip end of the second boom member facing downward with respect to a horizontal direction and a back surface of the arm facing the ground; The deep foundation excavator as described in claim 1, characterized in that it can be changed to a transport posture in which the tip of the first boom member is at the lowest position and the tip of the second boom member is facing upward relative to the horizontal direction, with the arm positioned above the second boom member.

4. a straight line connecting a connection portion between the vehicle body and the first boom member and a connection portion between the first boom member and the second boom member is defined as a first reference line, If a straight line connecting a connection portion between the first boom member and the second boom member and a connection portion between the second boom member and the arm is defined as a second reference line, The deep foundation excavator according to claim 3, characterized in that when the working device is in the transport posture, the angle between the first reference line and the second reference line is less than 90 degrees.

5. A first bracket to which one end of the positioning cylinder is connected is provided on a back surface of the first boom member, The deep foundation excavator as described in claim 1, characterized in that a second bracket to which the other end of the positioning cylinder is connected is provided on the back of the second boom member, located closer to the connection portion between the first boom member and the second boom member than the longitudinal middle portion of the second boom member.

6. The deep foundation excavator according to claim 1, characterized in that two of the positioning cylinders are provided in parallel between the first boom member and the second boom member.

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