Hang punching machine

Abstract

To provide a pile driver provided with a leader rotating device allowing large rotational force to be produced even in a compact configuration.SOLUTION: A leader rotation device 31 is provided with a rotational mechanism 32, a pair of hydraulic cylinders 33 vertically arranged inside of a fixed leader 24, and a bevel gear mechanism 34 converting reciprocal linear motion of the pair of hydraulic cylinders to forward and reverse rotational motion of the rotational mechanism, the rotational mechanism is provided with a fixed base 35 attached on an upper surface of the fixed leader and a rotational base 37 attached on a lower surface of the leader and rotatably supported on the fixed base, and the bevel gear mechanism comprises a bevel gear 39 coaxially arranged on the rotational base, a pair of sector gears 41 which engage the bevel gear on both sides thereof and are pivotably supported on a support shaft 40 arranged on the fixed leader, and a pair of cylinder connection arms 42 integrally arranged on the pair of sector gears, respectively, and reciprocally rotating the pair of sector gears in directions adversely to each other in accordance with the extension and contraction of the pair of hydraulic cylinders.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pile driver, and more particularly to a large pile driver of the three-point support type that rotatably supports a leader erected at the front of a base machine. [Background technology]

[0002] Among large three-point support pile drivers, there are known ones equipped with a rotating leader that rotates the leader around a central axis in order to change the excavation position or switch the excavation equipment (see, for example, Patent Document 1). Such a rotating leader consists of a fixed leader supported by a leader bracket and a rotating leader that is rotatably installed on the fixed leader, and the upper part of the rotating leader is supported from the rear by two backstays via a holder.

[0003] A pair of hydraulic cylinders for driving are arranged inside the fixed leader, and when one hydraulic cylinder is extended, the other hydraulic cylinder is contracted to rotate the bevel gear, so that the rotating leader can be rotated, for example, 90 degrees relative to the fixed leader. Such a leader rotation device is stored compactly using the internal space of the fixed leader where the gear part can be arranged without being exposed, and converts the reciprocating linear motion (thrust) of the hydraulic cylinder into forward and reverse rotational motion (rotational force) of the leader by meshing one bevel gear and one sector gear that make up the bevel gear. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 5-96133 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, large pile drivers are being fitted with long leaders of 40m or more in length in response to the increasing length of pile construction work. When a long leader is fitted, the weight increases accordingly compared to leaders of normal length, and the rotational force required to rotate the leader also increases. However, when trying to obtain a larger rotational force using conventional technology, a problem occurs in which the gear strength of the leader rotation device cannot be sufficiently secured. However, there is a space limit to enlarging the components, and the working conditions for inspection and maintenance become strict. In addition, changing the size of the gear to match the size of the leader results in increased costs because the parts cannot be shared.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a pile driver equipped with a leader rotation device that can obtain a large rotational force while having a compact configuration. [Means for solving the problem]

[0007] In order to achieve the above object, the pile driver of the present invention is provided with a fixed leader supported by a leader bracket provided at the front of a base machine, a rotating leader provided upright on the fixed leader so as to be rotatable coaxially, and a leader rotation device for applying a rotational force to the rotating leader, the leader rotation device including a rotation mechanism, a pair of hydraulic cylinders provided vertically inside the fixed leader, and a bevel gear mechanism for converting the reciprocating linear motion of the pair of hydraulic cylinders into forward and reverse rotational motion of the rotation mechanism, and the rotation mechanism is provided with a The bevel gear mechanism has a fixed base attached to the upper surface, and a rotating base attached to the underside of the rotating leader and rotatably supported on the fixed base via a bearing, and is characterized in that it has a bevel gear coaxially mounted on the rotating base, a pair of sector gears that mesh with both sides of the bevel gear and are pivotally supported on a support shaft provided on the fixed leader, and a pair of cylinder connecting arms that are integral with both sector gears and rotate both sector gears back and forth in opposite directions in accordance with the extension and contraction action of the pair of hydraulic cylinders.

[0008] The present invention is also characterized in that the support shaft is a common support shaft consisting of a single shaft, the sector gear and the cylinder connecting arm are aligned in the axial direction of the common support shaft, and the interior of the fixed leader is divided into two spaces by a boundary surface passing through the mutually orthogonal rotation axes of the bevel gear and the sector gear, and the pair of hydraulic cylinders are provided in one of the two spaces. Effect of the Invention

[0009] According to the pile driver of the present invention, the bevel gear mechanism of the leader rotation device has a pair of sector gears that mesh with both sides of the bevel gear that is installed coaxially with the leader rotation shaft, so that the contact area of ​​the meshing tooth surfaces can be doubled compared to conventional products, and sufficient gear strength can be secured against a larger rotational force. Moreover, the gear separation force is offset by the sector gears that face each other, and only pure rotational force can be applied to the bevel gear, so that a compact leader rotation device that does not require special reinforcement or structural strengthening can be achieved.

[0010] In addition, because the pair of sector gears are pivotally supported by a common support shaft consisting of a single shaft, the coaxiality between the sector gears is well maintained, and the meshing of the tooth surfaces and the sliding between the sector gears and the support shaft can be properly maintained. In other words, the power transmission efficiency of the bevel gear mechanism can be improved. Moreover, because the bearing structure supporting the shaft is a simple double-end support, the sector gear that is assembled in correspondence with the bevel gear can be arranged without difficulty. In particular, because the sector gear and the cylinder connecting arm are aligned in the axial direction of the common support shaft, the thrust of the hydraulic cylinder can be effectively applied to the sector gear.

[0011] Furthermore, the interior of the fixed leader is divided into two spaces by a boundary surface on the orthogonal rotation axis of the bevel gear mechanism, and a pair of hydraulic cylinders is provided in one of the spaces, so the other space without the hydraulic cylinders can be used for inspection and maintenance. In other words, by accessing through the lower opening of the fixed leader, the internal structure that is normally not visible from the outside can be easily and safely inspected, reducing the burden on workers. [Brief description of the drawings]

[0012] [Figure 1] 1 is a side view of a pile driver showing one embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 3 is a cross-sectional view of FIG. 2 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1 to 5 show an example of a pile driver of the present invention. As shown in Fig. 1, the base machine 12 of the pile driver 11 has an upper rotating body 14 rotatably mounted on an upper part of a lower running body 13 equipped with crawlers via a rotating bearing, and a leader bracket 17 to which a leader 15 and front jacks 16, 16 are attached is provided at the front part of the upper rotating body 14, and an outrigger box 19 to which rear jacks 18, 18 are attached and a counterweight 20 mounted on the outrigger box 19 are provided at the rear end part of the upper rotating body 14. Furthermore, a driver's cab 21 and a power unit 22 equipped with a hydraulic pump and the like are provided on the machine frame of the upper rotating body 14, and a gantry 23 that can be raised and lowered is provided above the rear part of the upper rotating body 14.

[0014] The leader 15 is composed of a cylindrical fixed leader 24 pivotally supported by the leader bracket 17, and a cylindrical rotating leader 25 that connects a plurality of leader members 25a and is coaxially rotatably erected on the fixed leader 24. A holder 26 that rotatably holds the rotating leader 25 is provided in the middle, and the tips of a pair of left and right back stays 27, 27 erected on the upper surface of the arm of the rear jack 18 are connected to the rear of the holder 26. The back stays 27, 27 are provided with stay cylinders 28, 28 at their lower ends, and the leader 15 can be tilted in the front-rear direction or left-right direction (vehicle width direction) by the extension and contraction of the stay cylinders 28, 28 while the leader 15 is supported from the rear. The leader 15 whose tilt has been adjusted is in an upright state, and its verticality is ensured.

[0015] The leader bracket 17 has a pair of leader holding parts (not shown) at the front end to hold the fixed leader 24, and as shown in FIG. 2, the leader holding parts and the pin hole blocks 30, 30 of the fixed leader 24 are engaged by the support pin 29. The pin hole 30a of the pin hole block 30 is formed as an elongated hole extending in the axial direction (up and down direction) of the fixed leader 24. This allows the leader 15 to swing freely in the front and back direction around the support pin 29, and further allows tilting in the left and right direction by the amount of backlash due to the vertical gap provided between the support pin 29 and the pin hole 30a.

[0016] 2 to 5 show a leader rotation device 31 and its mounting structure for applying a rotational force to the rotating leader 25. The leader rotation device 31 includes a rotation mechanism 32, a pair of hydraulic cylinders 33, 33 provided vertically inside the fixed leader 24, and a bevel gear mechanism 34 that converts the reciprocating linear motion of the pair of hydraulic cylinders 33, 33 into forward and reverse rotational motion of the rotation mechanism 32.

[0017] The rotation mechanism 32 has a bearing structure that holds the nested inner and outer rings so that they can rotate relative to each other, and has a fixed base 35 that is attached to the upper surface of the flange of the fixed leader 24, and a rotating base 37 that is attached to the lower surface of the flange of the rotating leader 25 (25a) and is rotatably supported by the fixed base 35 via bearings 36.

[0018] As can be seen from Fig. 3, the fixed base 35 is provided with a fan-shaped flange 35a to avoid the pair of left and right guide pipes (working device guide parts) 24a, 24a provided on the front side (left side of Fig. 3) of the fixed leader 24, and the flange 35a is provided with a total of three locking holes: one locking hole h1 corresponding to the neutral position where the working device (not shown) faces forward, and two locking holes h2, h3 located on both sides at 45 degree intervals. On the other hand, the rotating base 37 is provided with locking hole protrusions 37a at the edge of the disk shape that are selectively matched with the locking holes h1, h2, h3.

[0019] When the fixing pin (not shown) is removed from the locking hole h1 with the working device mounted on the front side, the engagement between the flange 35a and the locking hole protrusion 37a is released. Then, by operating the rotation mechanism 32, the rotating leader 25 is rotated 45 degrees to the right, for example, and the pin is fixed using the locking hole h3. Thus, through a series of operations including the attachment and detachment of the torque receiving piece 38 (see Patent Document 1), the phase between the fixed leader 24 and the rotating leader 25 is changed to a predetermined angle.

[0020] The bevel gear mechanism 34 includes a bevel gear 39 that is coaxially mounted on the underside of the rotating base 37, a pair of sector gears 41, 41 that mesh with both sides of the bevel gear 39 and are pivotally supported on a support shaft 40 provided on the fixed leader 24, and a pair of cylinder connecting arms 42, 42 that are integral with both sector gears 41, 41 and rotate the both sector gears 41, 41 back and forth in opposite directions in accordance with the expansion and contraction movement of a pair of hydraulic cylinders 33, 33.

[0021] As shown in FIG. 5, the support shaft 40 is a common support shaft 40 made of a single large diameter shaft, and is supported by a pair of bosses 43, 43 provided on both sides of the fixed leader 24 in the width direction (vertical direction in FIG. 5). The common support shaft 40 supports the sector gears 41, 41 between the bosses 43, 43 so that they can rotate in the front-rear direction (horizontal direction in FIG. 5) while penetrating the rotation bases 41a, 41a of the two sector gears 41, 41 facing each other. In this way, as shown in FIG. 2, the opposing sector gears 41, 41 form meshing tooth surfaces that are aligned in the width direction and vertical direction with the bevel gear 39. The meshing between the gears is maintained within the required range of the leader rotation angle, in other words, within the stroke range of the hydraulic cylinder 33 that constitutes the reciprocating rotation link.

[0022] The cylinder connecting arm 42 is a bifurcated member fixed to the rotation base 41a of the sector gear 41, and extends forward at the same height as the common support shaft 40, with the length of the arm being appropriate as the point of action of the thrust of the hydraulic cylinder 33. The interior of the fixed leader 24 is partitioned into two spaces, a front space SF and a rear space SR, by a boundary surface passing through the mutually orthogonal rotation axes Cz, Cy of the bevel gear 39 and the sector gears 41, 41, and the pair of cylinder connecting arms 42, 42 are arranged in the same direction, so that the pair of corresponding hydraulic cylinders 33, 33 are both provided in the front space SF (FIGS. 2 and 5).

[0023] 5, the sector gear 41 and the cylinder connecting arm 42 are aligned in the axial direction of the common support shaft 40. As a result, as shown in Figures 2, 4 and 5, when the hydraulic cylinder 33 is connected at its tube side to a bifurcated portion 44 provided on the bottom plate of the fixed leader 24 and at its rod side to the cylinder connecting arm 42 by upper and lower connecting pins 45, 46, the force for rotating the sector gear 41 can be transmitted locally to the rotation base 41a, that is, directly between the two members, the sector gear 41 and the cylinder connecting arm 42.

[0024] To change the excavation position using the pile driver 11 thus constructed, the supply and discharge of pressure oil to the pair of hydraulic cylinders 33, 33 is controlled, and when one hydraulic cylinder 33 is extended, the other hydraulic cylinder 33 is contracted, and the rotating mechanism 32 is rotated, for example, 45 degrees to the left via the bevel gear mechanism 34. At this time, since the force of the pair of sector gears 41, 41 is equal to each other and faces in the opposite directions, the torque acting on the bevel gear 39 by the meshing with both sector gears 41, 41 becomes a pure rotational force. In this way, the heavy rotating leader 25 is smoothly rotated on the fixed leader 24.

[0025] Thus, according to the pile driver 11 of the present invention, the bevel gear mechanism 34 of the leader rotation device 31 has a pair of sector gears 41, 41 that mesh with both sides of the bevel gear 39 that is provided coaxially with the leader rotation shaft, so that the contact area of ​​the meshing tooth surfaces can be doubled compared to the conventional product, and sufficient gear strength can be secured against a larger rotational force. Moreover, the gear separation force is offset by the sector gears 41, 41 that face each other, and only pure rotational force can be applied to the bevel gear 39, so that a compact leader rotation device 31 that does not require special reinforcement or structural strengthening can be achieved.

[0026] In addition, since the pair of sector gears 41, 41 are pivotally supported by the common support shaft 40 consisting of a single shaft, the mutual coaxiality of the sector gears 41, 41 is well maintained, and the meshing of the tooth surfaces and the sliding between the sector gears 41, 41 and the support shaft 40 can be properly maintained. In other words, the power transmission efficiency of the bevel gear mechanism 34 can be improved. Moreover, since the bearing structure supporting the shaft is a simple double-end support, the sector gears 41, 41 assembled corresponding to the bevel gear 39 can be arranged without difficulty. In particular, since the sector gear 41 and the cylinder connecting arm 42 are aligned in the axial direction of the common support shaft 40, the thrust of the hydraulic cylinder 33 can be effectively applied to the sector gear 41.

[0027] Furthermore, the interior of the fixed leader 24 is divided into two spaces by a boundary surface on the orthogonal rotation axes Cz, Cy of the bevel gear mechanism 34, and a pair of hydraulic cylinders 33, 33 are provided in one of the spaces, so that the other space without the hydraulic cylinders 33 can be utilized as a space for inspection and maintenance. In other words, by accessing through the lower opening of the fixed leader 24, the internal structure that is normally not visible from the outside can be easily and safely inspected, and the burden on the worker can be reduced.

[0028] In addition, by arranging a pair of hydraulic cylinders 33, 33 in the front space SF as in the embodiment, as can be imagined from Figure 2, etc., work such as removing and installing the hydraulic cylinder 33 and greasing each part can be easily performed through the side work openings 24b, 24c among the multiple work openings provided in the fixed leader 24, and inspection of the inside of the fixed leader 24, in particular the fixed state of the rotation mechanism 32 (loose bolts), can be more reliably performed through the lower work opening 24d that connects the inside and outside of the rear space SR, which contributes to improving the reliability of the pile driver 11.

[0029] The present invention is not limited to the above-mentioned embodiment, and the length of the leader, the shape of the basic cross section, and the range of the rotation angle can be appropriately changed according to the specifications of the pile driver. In this case, the leader rotation device makes good use of the bevel gear mechanism that has been provided conventionally, and even if the leader becomes large, the required strength can be satisfied without increasing the number of gears, which is advantageous in terms of cost and quality. In addition, if there is sufficient space, the two hydraulic cylinders can be arranged arbitrarily, and installation modes other than the vertical type can be considered. Furthermore, the support shaft of the sector gear that constitutes the bevel gear mechanism can be configured with two shafts corresponding to each sector gear, rather than a single shaft. [Explanation of symbols]

[0030] 11...pile driver, 12...base machine, 13...lower running body, 14...upper rotating body, 15...leader, 16...front jack, 17...leader bracket, 18...rear jack, 19...outrigger box, 20...counterweight, 21...operator cab, 22...power unit, 23...gantry, 24...fixed leader, 24a...guide pipe, 24b, 24c...side working opening, 24d...lower working opening, 25...rotating leader, 25a...leader member, 26...holder, 27...backs Tape, 28... stay cylinder, 29... support pin, 30... pin hole block, 30a... pin hole, 31... leader rotation device, 32... rotation mechanism, 33... hydraulic cylinder, 34... bevel gear mechanism, 35... fixed base, 35a... flange, 36... bearing, 37... rotation base, 37a... locking hole protrusion, 38... torque receiving piece, 39... bevel gear, 40... common support shaft, 41... sector gear, 41a... rotation base, 42... cylinder connecting arm, 43... boss, 44... bifurcated portion, 45, 46... connecting pin

Claims

1. A pile driver including a fixed leader supported by a leader bracket provided at the front of a base machine, a rotating leader provided upright on the fixed leader so as to be rotatable coaxially, and a leader rotation device for applying a rotational force to the rotating leader, The leader rotation device includes a rotation mechanism, a pair of hydraulic cylinders vertically disposed inside the fixed leader, and a bevel gear mechanism that converts the reciprocating linear motion of the pair of hydraulic cylinders into forward and reverse rotational motion of the rotation mechanism, the rotation mechanism includes a fixed base attached to an upper surface of the fixed reader, and a rotating base attached to a lower surface of the rotating reader and rotatably supported on the fixed base via a bearing, The bevel gear mechanism of this pile driver comprises a bevel gear coaxially mounted on the rotating base, a pair of sector gears that mesh with each other on both sides of the bevel gear and are pivotally supported on a support shaft provided on the fixed leader, and a pair of cylinder connecting arms that are integral with each of the sector gears and rotate the sector gears back and forth in opposite directions in accordance with the extension and contraction of the pair of hydraulic cylinders.

2. The support shaft is a common support shaft formed of a single shaft, 2. The pile driver according to claim 1, wherein the sector gear and the cylinder connecting arm are aligned in the axial direction of the common support shaft.

3. The interior of the fixed leader is divided into two spaces by a boundary surface passing through the mutually orthogonal rotation axes of the bevel gear and the sector gear, 3. The pile driver according to claim 1, wherein the pair of hydraulic cylinders are provided in one of the two spaces.

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