Construction machine

Abstract

To provide a construction machine equipped with a folding step which can be easily and safely operated.SOLUTION: The link mechanism 25 constituting the boarding and alighting step 22 includes a pair of front and rear first links 30 each having a base end portion connected to a side surface of the upper slewing body (a side surface of the floor frame 16) via a first pivot shaft 28 and a first bearing portion 29 supporting the first pivot shaft 28, a pair of front and rear second links 33 each having a base end portion connected to a back surface of the step plate 24 via a second pivot shaft 31 and a second bearing portion 32 supporting the second pivot shaft 31, and tip end portions of the pair of front and rear second links integrally connected to each other. Both end parts of the shaft connected and extended in the longitudinal direction are provided with a connecting shaft 35 respectively slid and moved in a long hole 34 provided in the intermediate part of the first link and a locking shaft 37 extended from the second link in the longitudinal direction, provided in parallel with the connecting shaft and engaged / disengaged with a V-shaped notch 36 provided in the tip part of the first link.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a construction machine, and more particularly to a construction machine provided with steps for getting on and off the operator's cab. [Background technology]

[0002] Generally, self-propelled construction machines used at construction sites have a cab mounted on one side of an upper rotating body, and workers can get in and out of the cab via steps that serve as footholds (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-98618 Summary of the Invention [Problem to be solved by the invention]

[0004] The steps described above are foldable to accommodate the transport conditions of construction machinery. However, with a foldable configuration, when preparing the step for use, the step plate must be lifted and held while pulling out a pair of brackets toward the outside of the upper rotating body, and then the step plate must be placed on top of them. This requires adjusting the position of each part, making the operation complicated, and also posing a risk of pinching fingers.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a construction machine equipped with a foldable step that can be operated easily and safely. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a construction machine comprising a lower traveling body, an upper rotating body rotatably provided on the upper part of the lower traveling body, a driver's cab mounted on one side of the upper rotating body, and steps serving as footholds for getting on and off the driver's cab, the steps comprising: a step plate that rotates vertically via a hinge provided on the side of the upper rotating body; a support position that is provided between the side of the upper rotating body and the back surface of the step plate, which is the side opposite to the tread surface, and that extends outward of the upper rotating body to horizontally support the step plate; and a storage position where it is folded against the side of the upper rotating body and stored under the back surface of the step plate, and the link mechanism is displaced to a pair of front and rear first links whose base ends are connected to the side of the upper rotating body via a first rotating shaft and a first bearing portion that supports the first rotating shaft, a pair of front and rear second links whose base ends are connected to the back surface of the step plate via a second rotating shaft and a second bearing portion that supports the second rotating shaft, and a shaft that extends in the front and rear direction and integrally connects the tip ends of the pair of front and rear second links, and both ends of the shaft that extends in the front and rear direction of the shaft are connected to the first links. and a locking shaft extending from the second link in the front-rear direction and parallel to the connecting shaft, which engages with and disengages from a dogleg-shaped notch provided at the tip of the first link. The first link and the second link rotate around the first rotation shaft and the second rotation shaft, respectively, following the rotation of the step plate, via the connecting shaft. When the step plate moves from a position hanging down from the side of the upper rotating body to a horizontal position, the first link and the second link each rotate around the stored position of the link mechanism, The connecting shaft slides in a direction from the base end side of the elongated hole toward the tip end and abuts against the tip end, and when the step plate transitions from a horizontal position to an upwardly inclined position with a preset inclination angle, the locking shaft is introduced into the notch which moves in an arc around the first pivot axis, and when the step plate transitions to the upwardly inclined position, the locking shaft is held in the middle part of the notch, and when the step plate transitions from the upwardly inclined position to a horizontal position, the connecting shaft is separated from the tip end of the elongated hole and the locking shaft is locked in the deepest part of the notch,The link mechanism is characterized by reaching a support position.

[0007] The first bearing portion, the first link, the second bearing portion, and the second link are characterized in that they are provided at different positions in the front-rear direction. [Effects of the Invention]

[0008] According to the construction machine of the present invention, in the link mechanism of the step serving as a platform for getting on and off, the first and second links move via the connecting shaft to follow the rotation of the step plate, the elongated hole that slides the connecting shaft gives the links freedom of movement, and the notch that locks the locking shaft interacts with the elongated hole to constrain the movement of the links and support the step plate, eliminating the need for a separate operation just to displace the link mechanism. By lifting or lowering the step plate, the link mechanism can be extended to the support position or folded to the storage position while maintaining the integrity of the links. In other words, a construction machine with a foldable step that is easy and safe to operate can be realized. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view of a pile driver showing an example of a construction machine according to the present invention. [Figure 2] FIG. 10 is a side view showing the step in use. [Figure 3] FIG. [Figure 4] FIG. 4 is a view taken along the line IV-IV in FIG. 3. [Figure 5] FIG. 10 is a side view showing the step in an unused state. [Figure 6] FIG. [Figure 7] FIG. 7 is a view taken along the line VII-VII in FIG. 6. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. [Figure 9] 9 is a cross-sectional view taken along the line IX-IX in FIG. 7. [Figure 10] FIG. 10 is a diagram showing the displacement state of the link mechanism when the step plate is rotated 30 degrees from the position in which it hangs down from the side of the upper rotating body. [Figure 11] FIG. 10 is a diagram showing the displacement state of the link mechanism when the step plate is rotated by 60 degrees. [Figure 12] 10 is a diagram showing the displacement state of the link mechanism when the step plate is rotated by 90 degrees. FIG. [Figure 13] FIG. 10 is an explanatory view of the operation of introducing the locking shaft into the notch. [Figure 14] FIG. 10 is a diagram showing the displacement state of the link mechanism when the step plate is rotated 102 degrees. [Figure 15] 10 is an explanatory view of the operation of locking the locking shaft to the deepest part of the notch. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1 to 15 show an example of a pile driver to which the present invention is applied, as an example of construction machinery. As shown in FIG. 1 , the pile driver 11 includes a rotatable upper rotating body 13 mounted on a crawler-equipped lower track body 12. The front center of the upper rotating body 13 is equipped with pile-driving equipment, including a leader 14 and an auger 15 that ascends and descends along the front of the leader 14. On both the left and right sides of the upper rotating body 13, a driver's cab 17 with a boarding / alighting access door 17a is mounted on a floor frame 16 on the right side, and an engine room (not shown) housing an engine and hydraulic pump is mounted on a floor frame on the left side. The sides of each floor frame define the side of the upper rotating body 13 (the surface corresponding to the transport width). Stabilizing jacks 18 are provided at four locations on the front, rear, left, and right sides of the upper rotating body 13, and a counterweight 19 is mounted at the rear end of the upper rotating body 13 to balance the machine.

[0011] When the pile driver 11 is used to bury steel pipe piles, a steel pipe pile is used as the construction member. The steel pipe pile (not shown) is connected via a cap rod 21 attached to the lower end of a drive rod 20, and is pressed into the ground by lowering the auger 15 while rotating the drive rod 20. When the pile driver 11 is used to improve the ground, a hollow rod (not shown) is used as the construction member. The upper end of the hollow rod is connected to a swivel above the auger 15, and the lower end is connected to a stirring rod. While the hollow rod is being rotated, a soil improvement agent such as cement milk is injected into the ground through the hollow rod and sprayed from the tip of the stirring rod.

[0012] To perform various construction methods such as burying piles and improving the ground, inside the cab 17, a number of operating levers, pedals, switches and other devices for operating the machine to travel, turn, raise and lower, and rotate the auger 15 are concentrated near the driver's seat. On the other hand, outside the cab 17, there is provided a step 22 that serves as a foothold for getting in and out of the entrance.

[0013] As shown in Figures 2 to 7, the step 22 has a step plate (tread) 24 that rotates up and down via a pair of front and rear hinges 23, 23 provided on the side of the floor frame 16, and a link mechanism 25 that is provided between the side of the floor frame 16 and the back surface of the step plate 24, which is the side opposite the tread surface, and is displaceable between a support position (Figures 2 to 4) that extends outward toward the outside of the upper rotating body and supports the step plate 24 horizontally, and a storage position (Figures 5 to 7) that is folded against the side of the floor frame 16 and stored on the back surface of the step plate 24.

[0014] The step plate 24 has a rectangular plate shape (see also FIG. 5) extending in the front-rear direction (left-right direction in FIG. 2), and is provided with necessary rigidity and strength by adding bending and reinforcing materials, and the tread side is subjected to anti-slip processing (burring processing). Also, as shown in FIG. 4 etc., the base end of the step plate 24 is provided with a hinge rotation shaft (hinge pin) 27 extending in the front-rear direction along the side of the floor frame 16, with the movable part 23a of the hinge 23 fixed and the fixed part 23b of the hinge 23 fixed to the side of the floor frame 16 with a bolt 26.

[0015] The link mechanism 25 is made up of thick plates or blocks, and mainly comprises a pair of front and rear first links 30, 30 whose base ends are connected to the side surfaces of the floor frame 16 via first rotating shafts (first pins) 28 and first bearing portions 29 that support the first rotating shafts, a pair of front and rear second links 33, 33 whose base ends are connected to the back surfaces of the step plates 24 via second rotating shafts (second pins) 31 and second bearing portions 32 that support the second rotating shafts, and a pair of front and rear second links 33, 33 whose tip ends are integrally connected to each other. The shaft extends in the front-rear direction, and has a circular cross-section connecting shaft 35, both ends of which slide in long holes 34 provided in the middle of first link 30; a circular cross-section locking shaft 37 extends in the front-rear direction from second link 33 and is provided parallel to connecting shaft 35, and engages with and disengages from a dogleg-shaped (approximately L-shaped) notch 36 provided at the tip of first link 30; and a plate-shaped abutment portion 38, which is provided parallel to locking shaft 37 at the base end of second link 33 and with which the tip of first link 30 comes into contact at the support position of link mechanism 25.

[0016] The first bearing portion 29 has a shaft hole for the first pivot shaft 28 and is fixed to the side surface of the floor frame 16. The distance between the paired front and rear first bearing portions 29, 29 is set to match the distance (mounting span) between the paired front and rear hinges 23, 23, which are attached taking into account the length of the step plate 24 (FIG. 2). The second bearing portion 32 has a shaft hole for the second pivot shaft 31 and is fixed to the back surface of the step plate 24. The distance between the paired front and rear second bearing portions 32, 32 is set to be smaller than the distance between the first bearing portions 29, 29, taking into account the space in the front-rear direction in which the first links 30, 30 and second links 33, 33 are arranged.

[0017] 3 and 6, the first bearing portion 29, the first link 30, the second bearing portion 32, and the second link 33 are provided at different positions in the front-rear direction (left-right direction in FIG. 3). Specifically, in a state where the pair of front and rear second links 33 are nested inside the pair of front and rear first links 30 (left side in FIG. 3) via both ends of the connecting shaft 35, the pair of front and rear first bearing portions 29 are arranged outside the pair of front and rear first links 30, and the pair of front and rear second bearing portions 32 are arranged inside the pair of front and rear second links 33 (FIGS. 2 and 5).

[0018] As shown in Figures 7 to 9, when the link mechanism 25 is in the retracted position, the first link 30 and the second link 33 hang down under their own weight from the side surface of the floor frame 16 (the back surface of the step plate 24) and are placed in a state where they do not interact with each other. In this state, the connecting shaft 35 is located on the base end side (closer to the first pivot shaft 28) of the elongated hole 34 extending in the longitudinal direction of the first link 30, while the locking shaft 37 is located on the opposite side of the notch 36 (immediately above the first pivot shaft 28) with the elongated hole 34 sandwiched therebetween. When the link mechanism 25 is in the retracted position, the notch 36 opens toward the outside of the upper rotating body, and this opening 36a is formed to be large enough to allow the locking shaft 37 to pass through with ease. Furthermore, the area from the dogleg-shaped bent portion 36b to the deepest portion 36c extends in the longitudinal direction of the first link 30, similar to the shape of the elongated hole 34.

[0019] The following describes the movements of each part when the step 22 is operated to transition from a non-use state (FIG. 7) in which the step plate 24 hangs down from the side of the floor frame 16 to a use state (FIG. 4) in which the step plate 24 rotates outward to a horizontal position, with reference to FIGS. 10 to 15. Note that, to make the explanation easier to understand, each of the referenced figures shows the link mechanism 25 as viewed from the axial direction.

[0020] When the step 22 is in an unused state (FIG. 7), by lifting the tip (lower end) of the step plate 24 and rotating the step plate 24 about the hinge rotation shaft 27, the first link 30 and the second link 33 rotate about the first rotation shaft 28 and the second rotation shaft 31, respectively, following the rotation of the step plate 24, via the connecting shaft 35, i.e., in a state in which the rotation force of the step plate 24 can be transmitted (a state in which they interact with each other). In other words, the first link 30 and the second link 33 each rotate from the stored position of the link mechanism 25 (FIG. 7) as a starting point, and slide the connecting shaft 35 in a direction from the base end side of the elongated hole 34 toward the tip end, passing through the state of FIG. 10 (the angle θ between the side surface of the floor frame 16 and the tread surface of the step plate 24 = 30 degrees), and then the connecting shaft 35 comes into contact with the tip end of the elongated hole 34 (θ = 60 degrees) as shown in FIG. 11. Thereafter, the first link 30 and the second link 33 move relatively with the connecting shaft 35 tracing an arcuate path 39 centered on the first rotation shaft 28, and the locking shaft 37 tracing an arcuate path 40 centered on the connecting shaft 35. In this way, while the first link 30 and the second link 33 are simultaneously rotated, the step plate 24 reaches a horizontal position (θ=90 degrees) as shown in FIG.

[0021] When the step plate 24 transitions from a horizontal position to an upwardly inclined position (FIG. 14) at a preset inclination angle (12 degrees from the horizontal in this embodiment), the locking shaft 37 is introduced into the notch 36 that moves in an arc around the first rotating shaft 28 (FIG. 13(b)), as shown in the order of FIGS. 13(a), 13(b), and 13(c). When the step plate 24 transitions to the upwardly inclined position, that is, when the extension directions of the first link 30 and the second link 33 are aligned (FIG. 13(c)), the locking shaft 37 introduced through the open portion 36a of the notch 36 is held in the bent portion (middle portion) 36b of the notch 36. In this state where the locking shaft 37 is held, the first rotating shaft 28, the connecting shaft 35, the locking shaft 37, and the second rotating shaft 31 are aligned in a straight line, as shown in FIG. As a result, tension is generated in the first link 30 and the second link 33, the link mechanism 25 is tensed, and the operation of lifting the tip end of the step plate 24 is restricted (θ=102 degrees).

[0022] Here, if the step plate 24, which is in an upwardly inclined position, is rotated downward (to the reverse side) under its own weight, that is, if the link mechanism 25 is operated in a direction to release tension, the first link 30 and the second link 33 will rotate relatively under their own weight, and the locking shaft 37 will come out of the notch 36, as shown in the order of Figures 13(c), (b), and (a). To prevent this return movement, the connecting shaft 35 is grasped and supported at a predetermined position (preferably the middle position in the length direction) so that the rotational force due to the weight of the second link 33 does not act on the first link 30 via the connecting shaft 35.

[0023] As a result, when the step plate 24 transitions from an upwardly inclined position to a horizontal position, the link mechanism 25 receives support from the connecting shaft 35, and the first link 30 and the second link 33 move linearly relative to each other. That is, as shown in FIG. 15 , the connecting shaft 35 is moved away from the tip of the elongated hole 34, and the locking shaft 37 is locked in the deepest portion 36c of the notch 36, thereby reaching the support position (θ=90°). At this support position, the relative movement of the links 30 and 33, including longitudinal movement (movement in the direction in which the first pivot shaft 28 and the second pivot shaft 31 approach each other), is restricted by the locking action of the locking shaft 37, and the rotation of the links 30 and 33 is restricted by the locking action of the connecting shaft 35 and the locking shaft 37. The tip of the first link 30 is in light contact with the abutment portion 38. Through this series of operations, the step 22 is brought into a usable state (FIGS. 2 to 4). In this operation, only the connecting shaft 35 (preferably near the center in the longitudinal direction) is supported, and there is no need to directly support the movable part of the link mechanism 25, so the work can be done safely without the risk of pinching the fingers.

[0024] On the other hand, when the step 22 is shifted from the use state (FIG. 4) to the non-use state (FIG. 7), the above-described procedure is reversed. In this case, when the tip of the step plate 24 is lifted, the locking shaft 37 is not held by the bent portion 36b of the notch 36, but is guided directly out of the notch 36 through the open portion 36a. Therefore, when the locking shaft 37 comes out of the notch 36, the first link 30 and the second link 33 begin to rotate relatively under their own weight, eliminating the need to grip the connecting shaft 35 as described above.

[0025] Furthermore, since the tip of the first link 30 remains in contact with the abutment portion 38 until the locking shaft 37 moves from the deepest portion 36c of the notch 36 to the open portion 36a, the locking shaft 37 will not come out of the notch 36 before the step plate 24 has been rotated (lifted) a certain amount. As the step plate 24 rotates downward (toward the reverse side), the link mechanism 25 reaches the stored position by causing the first link 30 and the second link 33 to hang down from the side of the floor frame 16. This series of operations puts the step 22 into an unused state (Figure 7).

[0026] Thus, according to the construction machine of the present invention, in the link mechanism 25 of the step 22, which serves as a platform for getting on and off, the first link 30 and the second link 33 move via the connecting shaft 35 in response to the rotation of the step plate 24, the elongated hole 34 that slides the connecting shaft 35 gives the links 30, 33 freedom of movement relative to each other, and the notch 36 that engages the locking shaft 37 interacts with the elongated hole 34 to constrain the movement of the links 30, 33 relative to each other and support the step plate 24. This eliminates the need for a separate operation just to displace the link mechanism 25, and the link mechanism 25 can be extended to the support position or folded to the storage position while maintaining the integrity of the links 30, 33 relative to each other by lifting or lowering the step plate 24. In other words, a construction machine equipped with a foldable step 22 that is easy and safe to operate can be realized.

[0027] Furthermore, since the first bearing portion 29, the first link 30, the second bearing portion 32, and the second link 33 are provided at different positions in the front-to-rear direction, the amount of protrusion from the side of the floor frame 16 is reduced when the link mechanism 25 is in the stored position (Figure 7). Moreover, the link mechanism 25 is configured compactly in the front-to-rear direction, improving the unity between adjacent parts, while allowing the rotation axes 28, 31 to be provided at appropriate positions that avoid the rotation trajectories of the links 30, 33 (Figures 3 and 6).

[0028] The present invention is not limited to the above-described embodiment, and the structure and arrangement of the step plates and link mechanisms that constitute the steps for getting on and off can be changed as appropriate as long as the scaffolding function is not impaired. Furthermore, multiple steps may be provided, and these may be provided in a row from front to back, or additional steps may be provided on the side of the upper rotating body opposite the side where the cab is located. Furthermore, while a pile driver has been exemplified as a construction machine, the present invention is not limited to this, and can be applied to various construction machines, such as earth drills and cranes, that have a cab mounted on one side of the upper rotating body. [Explanation of symbols]

[0029] 11...pile driver, 12...lower running body, 13...upper rotating body, 14...leader, 15...auger, 16...floor frame, 17...operator's cab, 17a...door, 18...jack, 19...counterweight, 20...drive rod, 21...cap rod, 22...step, 23...hinge, 23a...moving part, 23b...fixed part, 24...step plate, 25...link mechanism, 26...bolt, 27...hinge pivot shaft, 28...first pivot shaft, 29...first bearing part, 30...first link, 31...second pivot shaft, 32...second bearing part, 33...second link, 34...long hole, 35...connecting shaft, 36...notch, 36a...opening part, 36b...folded part, 36c...deepest part, 37...locking shaft, 38...contact part, 39, 40...arc track

Claims

1. a lower running body; an upper rotating body rotatably provided on an upper part of the lower traveling body; an operator's cab mounted on one side of the upper rotating body; a step serving as a foothold for getting in and out of the cab; In a construction machine equipped with The steps include: a step plate that rotates vertically via a hinge provided on a side surface of the upper rotating body; a link mechanism that is provided between the side surface of the upper rotating body and the back surface of the step plate, which is the side opposite to the tread surface, and that is displaceable between a support position where the step plate is horizontally supported by projecting outward of the upper rotating body, and a storage position where the step plate is folded against the side surface of the upper rotating body and stored on the back surface of the step plate; and The link mechanism includes: a pair of front and rear first links, each having a base end connected to a side surface of the upper rotating body via a first rotating shaft and a first bearing portion supporting the first rotating shaft; a pair of front and rear second links, each having a base end connected to the rear surface of the step plate via a second rotation shaft and a second bearing portion supporting the second rotation shaft; a connecting shaft that integrally connects tip ends of the pair of front and rear second links and extends in the front-rear direction, with both ends of the connecting shaft extending in the front-rear direction sliding in long holes provided in intermediate portions of the first links; a locking shaft extending in the front-rear direction from the second link and parallel to the connecting shaft, the locking shaft engaging with and disengaging from a dogleg-shaped notch provided at the tip of the first link; and The first link and the second link are The step plate rotates around the first rotation axis and the second rotation axis in accordance with the rotation of the step plate via the connecting shaft, When the step plate transitions from a position hanging down from the side surface of the upper rotating body to a horizontal position, the step plate rotates around the storage position of the link mechanism as a starting point, and the connecting shaft slides in a direction from the base end side of the elongated hole toward the tip end and abuts against the tip end, When the step plate shifts from a horizontal position to an upwardly inclined position at a preset inclination angle, the locking shaft is introduced into the notch that moves in an arc around the first pivot shaft, When the step plate is shifted to the upwardly inclined position, the locking shaft is held in the middle portion of the notch, When the step plate transitions from the upwardly inclined position to a horizontal position, the connecting shaft is moved away from the tip of the elongated hole and the locking shaft is locked in the deepest part of the notch, thereby reaching the support position of the link mechanism.

2. 2. The construction machine according to claim 1, wherein the first bearing portion, the first link, the second bearing portion, and the second link are provided at different positions in the front-to-rear direction.

Images