Stepladder storage structure

Abstract

To provide a stepladder storage structure difficult to come into contact with a swivel base even when a stepladder is installed on a travel body.SOLUTION: A stepladder storage structure S in a rough terrain crane 1 comprises a stepladder 8 including hinges 83 and 83 and opening stops 84 and 84 on both right and left surfaces, a pair of right and left inclined guides 2 and 2 for guiding the hinges 83 and 83 and the opening stops 84 and 84 of the linearly opened stepladder on the upper surface of a travel body 10. A distance between the deepest parts (between upright parts 22 and 22) of the inclined guides 2 and 2 approaching the upper surface of the travel body 10 substantially coincides with a distance between the hinges 83 and 83 of the stepladder 8.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a storage structure for a stepladder in a mobile crane.

Background Art

[0002] Conventionally, in a mobile crane, when the boom is extended / retracted, an operator works on the stepladder, such as inserting / removing pins or detaching / attaching connectors while standing on the stepladder. For example, for a tension device of a boom attached to the tip of the boom, an operator may perform assembly / disassembly work of the tension device while standing on the stepladder.

[0003] Since operations such as extending / retracting the boom need to be performed on-site, the mobile crane needs to move with the stepladder mounted. However, there are various restrictions on the position where the stepladder is mounted.

[0004] For example, when the stepladder is mounted on the slewing platform or the traveling body (on the carrier frame), there are problems such as interference with the cab or counterweight during slewing, narrowing of the working space or the lifting / lowering path to the cab, hindrance to movement due to the stepladder at the feet and a decrease in work safety, complication of movement and insertion / removal of the stepladder, and the need to lower the stepladder during engine maintenance.

[0005] On the other hand, when the stepladder is mounted under the vehicle, there are problems such as the stepladder being soiled or damaged by mud splashes, flying stones, snow accumulation, etc., the need to crouch down to take out the stepladder, and a decrease in traveling performance due to the influence on the departure angle.

[0006] Therefore, Patent Document 1 describes a storage structure for a stepladder that does not interfere with work and is easy to insert / remove. In this storage structure for the stepladder in Patent Document 1, the stepladder is stored by storage means installed in the space between the wheels and the outriggers.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, if there are changes or increases in the equipment to be mounted, there may be cases where a step ladder cannot be stored between the wheels and outriggers as in Patent Document 1. In such a case, it is conceivable to mount the step ladder on the traveling body (on the carrier frame). However, as described above, since the gap between the lower surface of the slewing platform and the upper surface of the traveling body is narrow, there is a risk that the slewing platform and the step ladder will come into contact during slewing.

[0009] Therefore, an object of the present invention is to provide a storage structure for a step ladder that is less likely to come into contact with the slewing platform even when the step ladder is installed on the traveling body.

Means for Solving the Problems

[0010] To achieve the above object, the storage structure of the step ladder of the mobile crane of the present invention is such that the step ladder has hinge portions and opening stop portions on both left and right side surfaces, and on the upper surface of the traveling body, there are provided a pair of left and right inclined guide portions for guiding the pair of left and right hinge portions and opening stop portions of the step ladder in a linearly opened state. Here, the "both left and right side surfaces" of the step ladder refers to the "left side surface" and the "right side surface" as seen from the state facing the tread of the step ladder (the position where the tread extends horizontally).

Effects of the Invention

[0011] As described above, the storage structure of the step ladder of the mobile crane of the present invention is such that the step ladder has hinge portions and opening stop portions on both left and right side surfaces, and on the upper surface of the traveling body, there are provided a pair of left and right inclined guide portions for guiding the pair of left and right hinge portions and opening stop portions of the step ladder in a linearly opened state. With such a configuration, it becomes a storage structure for the step ladder that is less likely to come into contact with the slewing platform even when the step ladder is installed on the traveling body.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following examples, a rough terrain crane (1) will be described as an example of a mobile crane, but it is not limited thereto. Any mobile crane that uses a step ladder may be used, for example, an all terrain crane or the like.

Example

[0014] (Overall Structure) First, using FIG. 1, the overall structure of the rough terrain crane 1 as a mobile crane of the present invention will be described. As shown in FIG. 1, the rough terrain crane 1 of this embodiment includes a traveling body 10 having a traveling function, and a slewing platform 12 having a working boom 14 and being mounted on the traveling body 10 so as to be rotatable (rotatable in the horizontal direction). And, as will be described later, a stepladder storage structure S is arranged above the traveling body 10 and below the slewing platform 12 in the traveling posture.

[0015] The slewing platform 12 is mainly composed of a cabin 18 that serves as a driver's seat during traveling and a control seat during work, a counterweight 19 arranged at the rear end, and a boom 14 that is attached to a bracket 13 erected on the slewing platform 12 so as to be able to rise and fall. This slewing platform 12 is arranged on the left side of the traveling body 10.

[0016] The boom 14 is formed in a telescopic manner by a plurality of cylinders, and is composed of a base boom 141, one or more intermediate booms 142, and a tip boom 143. An elevation cylinder 15 is attached between the base boom 141 and the bracket 13 of the slewing platform 12, and by expanding and contracting the elevation cylinder 15, the entire boom 14 can be elevated.

[0017] Furthermore, a telescopic cylinder (not shown) is installed inside the boom 14, and by expanding and contracting the telescopic cylinder, the length of the entire boom 14 can be expanded and contracted. And, a jib (and a tension rod) is stored in a horizontally held posture on the side surface of the base boom 141.

[0018] A boom head 144 is attached to the tip of the tip boom 143, and a wire rope 17 is suspended through a sheave of the boom head 144. The wire rope 17 is wound around a hook block 16.

[0019] The traveling body 10 includes wheels 10a that are rotationally driven during traveling, ···, and outriggers 11 that lift and support the traveling body 10 during work, ···. And on the traveling body 10 of this embodiment, a storage structure S for a step ladder is provided. Hereinafter, the storage structure S for the step ladder will be specifically described.

[0020] (Configuration of the step ladder) First, with reference to FIG. 2, the configuration of the step ladder 8 stored in the storage structure S for the step ladder will be described. As shown in FIG. 2, the step ladder 8 includes four columns 81, ···, a plurality of treads 82 spanned between a pair of columns 81, 81, ···, left and right hinge portions 83, 83, a stopper portion 84 for fixing the angles of the hinge portions 83, 83, a lock portion 85, and a top plate 86.

[0021] Among these, the hinge portion 83 is disposed outside the column 81, and the stopper portion 84 and the lock portion 85 are disposed further outside the hinge portion 83. Therefore, in order from the outside, the stopper portion 84 and the lock portion 85 are on the outermost side, the hinge portion 83 is on the inner side thereof, and the column 81 is on the innermost side in the positional relationship.

[0022] The stopper portion 84 is rotatably supported on one of the opposing columns 81, 81 via the hinge portion 83 and can be locked / released to the lock portion 85 fixed to the other. Thereby, the angle formed between the opposing columns 81, 81 can be fixed during use.

[0023] And when being stored, when this step ladder 8 is deployed linearly (that is, in a state where the two columns 81, 81 sandwiching the hinge portion 83 are opened linearly (180 degrees). The angle of the hinge portion 83 is fixed by the opening stopper portion 84.) As shown in FIG. 2(c), when viewed from the side, the hinge portion 83 (near the rotation axis) protrudes downward from the column 81. That is, when the step ladder 8 is deployed linearly during storage, the hinge portion 83 protrudes out of the plane formed by the columns 81, 81 and the tread bar 82, ··· in a triangular shape on one side. Note that on the other side of the hinge portion 83, there are no large protruding parts and it is almost flat.

[0024] (Configuration of the storage structure of the step ladder) And the storage structure S of the step ladder of this embodiment is arranged on the running body 10 (fender) and below the slewing platform 12 as shown in FIGS. 3(a) and (b). More specifically, in the vehicle longitudinal direction, the inclination guide portion 2, the long hole 3, which are the centers of the storage structure S of the step ladder, are arranged on the left side of the running body 10, slightly on the rear side of the vehicle from the rotation center of the slewing platform 12. In the vehicle lateral direction, the center line of the storage structure S of the step ladder is positioned slightly closer to the inside than the left - right center line of the space on the left side of the slewing platform 12. Here, the left side means the left side when viewed from the rear of the vehicle body, and the right side means the right side when viewed from the rear of the vehicle body.

[0025] Furthermore, in addition to the inclination guide portion 2 and the long hole 3, the storage structure S of the step ladder of this embodiment includes two (four) support members 5, 5 for each column 81 on the front side of the vehicle from the central inclination guide portions 2, 2, and two (four) support members 5, 5 for each column 81 on the rear side of the vehicle and a support 4 at the rearmost (see also FIG. 7). In addition, the storage structure S of the step ladder is provided with an attachment portion 61 for attaching a vibration - preventing support 60 for pressing the front column 81.

[0026] A pair of left and right inclined guide portions 2 are installed to guide (position) a pair of left and right hinge portions 83, 83 and opening stopper portions 84, 84 (and lock portions 85, 85) of the step ladder 8 in an open state, as shown in FIGS. 4(a) to 4(c). That is, the inclined guide portion 2 closer to the outside of the vehicle guides the step ladder 8 toward the inside of the vehicle, and the inclined guide portion 2 closer to the inside of the vehicle guides the step ladder 8 toward the outside of the vehicle.

[0027] And the distance between the left inclined guide portion 2 and the right inclined guide portion 2 is adjusted as follows. That is, the distance between the left and right upright portions 22, 22 is made substantially the same as the distance between the left and right hinge portions 83, 83 of the step ladder 8 (with a predetermined margin), and is made narrower than the distance between the left and right opening stopper portions 84, 84 (see FIGS. 8(a) and 8(b)).

[0028] Furthermore, the distance between the upper end portions of the left and right inclined portions 23, 23 is made wider than the distance between the left and right hinge portions 83, 83 of the step ladder 8, and the distance between the lower end portions of the left and right inclined portions 23, 23 is made narrower than the distance between the left and right opening stopper portions 84, 84 of the step ladder 8 (see FIGS. 8(a) and 8(b)).

[0029] More specifically, each inclined guide portion 2 is formed by bending a metal plate twice, and includes an attachment portion 21 to the traveling body 10 (the fender), an upright portion 22 that is continuous with the attachment portion 21 and stands upright at about 90 degrees, and an inclined portion 23 that is continuous with the upright portion 22 and is inclined at about 45 degrees (see FIG. 4(b)).

[0030] Two holes 21a, 21a are provided in the attachment portion 21 for bolt fastening to the fender. The upright portion 22 and the inclined portion 23 form a trapezoidal or Mount Fuji shape in a side view (see FIG. 4(c)). The inclined portion 23 of the inclined guide portion 2 on the outside of the vehicle is arranged such that the diagonally upward-facing surface faces the inside of the vehicle, and the inclined portion 23 of the inclined guide portion 2 on the inside of the vehicle is arranged such that the diagonally upward-facing surface faces the outside of the vehicle (see FIGS. 3(a) and 4(a)).

[0031] The pair of left and right elongated holes 3, 3 are oval-shaped openings extending in the vehicle front-rear direction formed in the fenders of the traveling body 10 as shown in Fig. 3(a), and are a series of openings including a semicircular opening at the front end, a semicircular opening at the rear end, and a rectangular (square) opening therebetween. This elongated hole 3 is arranged substantially parallel to the inclined guide portion 2 and immediately inside (on the center line side of the step ladder 8) adjacent to the inclined guide portion 2.

[0032] The distance between the left elongated hole 3 and the right elongated hole 3 is made substantially the same as the distance between the left and right hinge portions 83. The length of the elongated hole 3 in the vehicle front-rear direction is set to a length that can accommodate the hinge portions 83, 83 of the step ladder 8 that protrude out of the plane in a triangular shape when open, and the width of the elongated hole 3 in the vehicle left-right direction is set to a width that can accommodate the hinge portion 83.

[0033] The support 4 is composed of a rectangular mounting plate 40 and a pair of cases 41, 41 installed at both ends of the mounting plate 40 as shown in Figs. 5(a) to (c). The mounting plate 40 is provided with mounting holes on both the left and right sides. The case 41 has its forward-facing side and outward-facing side open when installed on the mounting plate 40. In other words, the rearward-facing side, inward-facing side, and upward-facing top surface of the case 41 are closed.

[0034] The distance between the left and right supports 4, 4 has a space that can accommodate the synthetic resin anti-slip caps at the ends of the columns 81, 81 of the step ladder 8. Therefore, in the state where the step ladder 8 is stored (see Fig. 7), the anti-slip caps at the ends of the columns 81, 81 are inserted into the cases 41, 41 so that they hardly move in either the left or right direction of the vehicle. On the other hand, the step ladder 8 cannot slide in the vehicle rear direction, but can slide in the vehicle front direction.

[0035] The support member 5 is formed by bending a steel plate into a V shape or a W shape, and is installed on the traveling body 10 in an inverted V shape or an inverted W shape with the open side facing downward. The support members 5, 5 support the middle part and the lower part of the column 81 of the step ladder 8 from below.

[0036] The anti-tip support 60 is fixed by a fastening screw 62 as a fixing device screwed into the mounting portion 61, so as to hold down the columns 81, 81 of the step ladder 8 from above. That is, the anti-tip support 60 has arms 60a, 60b extending left and right and a hole 60c for the fastening screw. The left and right arms 60a, 60b have different lengths, with a short arm 60a closer to the outside of the vehicle and a long arm 60b closer to the inside of the vehicle.

[0037] When actually using the anti-tip support 60, after placing the step ladder 8 in the stored position (that is, in a state where the left and right hinge portions 83 of the step ladder 8 opened 180 degrees are immersed in the long holes 3), place it on the columns 81, 81 from above so as to grasp them, and then fix the columns 81, 81 by manually tightening the fastening screw 62 which is the fixing device.

[0038] (Function) Next, with reference to FIGS. 7 to 9, the function when the step ladder 8 is stored using the storage structure S of the step ladder of the present embodiment will be described.

[0039] FIGS. 7(a) and (b) show a state in which the step ladder 8 is stored in the storage structure S of the step ladder. As shown in FIGS. 7(a) and (b), when storing the step ladder 8, the step ladder 8 is opened linearly (180 degrees), and in the "correct" state where the hinge portion 83 and the anti-opening portion 84 face downward, it is lifted and placed on the fender of the traveling body 10. Then, while positioning the step ladder 8 in the left-right direction of the vehicle by the left and right inclined guide portions 2, 2, it is slid from the front of the vehicle toward the rear of the vehicle, and the anti-slip caps at the ends of the columns 81, 81 are inserted into the cases 41, 41.

[0040] Almost simultaneously with this backward sliding movement, the left and right hinge portions 83 and the locking portions 84 near the center of the step ladder 8 are biased by the inclined guide portions 2 toward the center line of the storage structure S of the step ladder, and the lower portions of the hinge portions 83 are inserted into the long holes 3, 3. Then, as shown in FIGS. 8(a) and 9(a), the height on the fender of the step ladder 8 is kept low, and the distance from the lower surface of the swivel base 12 is 43 (mm), so that a sufficient distance can be taken. That is, by inserting the hinge portion 83 that protrudes largely out of the plane into the long hole 3, the height on the fender of the entire step ladder 8 can be suppressed.

[0041] Thereafter, by using the anti-slip support 60 and the fastening screw 62 to suppress the position of the step ladder 8 near the front of the columns 81, 81, it is possible to prevent the step ladder 8 from detaching from the storage structure S of the step ladder. That is, the rearmost part of the step ladder 8 has the anti-slip cap at the end of the column 81 inserted into the case 41 of the support 4, the central part has the hinge portion 83 inserted into the long hole 3, and the position near the front is pressed by the anti-slip support 60, so that the step ladder 8 can be prevented from shifting left and right, front and back, or detaching from the storage structure S of the step ladder.

[0042] On the other hand, even if an attempt is made to store the step ladder in the storage structure S of the step ladder in the "wrong" state where the hinge portion 83 and the locking portion 84 are on top, as shown in FIGS. 8(b) and 9(b), the height on the fender of the step ladder 8 becomes high, the distance from the lower surface of the swivel base 12 is 1 (mm), and there is a risk of contacting the swivel lock pin boss that protrudes downward from the lower surface of the swivel base 12 without being able to take a sufficient distance. However, even if an attempt is made to store the step ladder 8 in such a wrong state, it does not fit well into the inclined guide portions 2, 2, so that it is easy for the operator to notice that it is in the wrong state. Furthermore, since the fastening screw 62 cannot reach the attachment portion 61, the position near the front of the column 81 cannot be fixed, so it can be said that it is easier to notice that it is in a more wrong state.

[0043] This is because the locking stop portion 84 (and the locking portion 85) cannot fully fit between the upright portions 22 of the inclined guide portions 2, 2 and is placed on the inclined portion 23. Furthermore, since the hinge portion 83 protruding out of the plane protrudes greatly upward, the overall height of the step ladder 8 becomes higher. In addition, due to the angling of the columns 81, 81 of the step ladder 8, it becomes difficult for the ends of the columns 81, 81 to be slidably inserted backward into the cases 41, 41.

[0044] (Effect) Next, the effects of the storage structure S of the step ladder of the present embodiment will be listed and explained.

[0045] (1) As described above, in the storage structure S of the step ladder in the rough terrain crane 1 as a mobile crane of the present embodiment, the step ladder 8 has hinge portions 83, 83 and locking stop portions 84, 84 on both left and right side surfaces, and on the upper surface of the traveling body 10, there are provided a pair of left and right inclined guide portions 2, 2 for guiding the pair of left and right hinge portions 83, 83 and locking stop portions 84, 84 of the step ladder in a linearly opened state. With such a configuration, even if the step ladder 8 is installed on the traveling body 10 in an opened state, the distance from the slewing platform 12 can be made sufficiently wide, so that it becomes a storage structure S of the step ladder that is difficult to contact the slewing platform 12.

[0046] (2) Also, the distance between the deepest portions (that is, between the upright portions 22, 22) of the pair of left and right inclined guide portions 2, 2 close to the upper surface of the traveling body 10 is formed to substantially match the distance between the pair of left and right hinge portions 83, 83 of the step ladder 8, so that the step ladder 8 can be accurately positioned in the left - right direction of the vehicle.

[0047] (3) Further, on the fender upper surface of the traveling body 10, inside the pair of left and right inclined guide portions 2, 2, elongated holes 3, 3 into which the protruding portions of the pair of left and right hinge portions 83, 83 of the step ladder 8 in a linearly opened state are inserted are further provided. Therefore, by inserting the hinge portion 83 protruding out of the plane into this elongated hole 3, the overall height can be kept low.

[0048] (4) Further, anti-slip caps are respectively attached to the tips of the four columns 81, ··· of the stepladder 8, and two supports 4, 4 capable of respectively storing the anti-slip caps at the tips of the columns 81 of the stepladder 8 in an open, linear state are installed on the upper surface of the traveling body 10. Therefore, it is possible to prevent the stepladder 8 from moving in the left-right direction of the vehicle and from moving rearward of the vehicle and falling off.

[0049] (5) Furthermore, since it further includes an anti-sway support 60 that suppresses two of the four columns 81, ··· of the stepladder 8 and fastening screws 62, 62 for removably fixing the anti-sway support 60, the entire stepladder 8 can be pressed against and fixed to the traveling body 10 side. In this case, since the lower part of the hinge portion 83 is inserted into the long hole 3, it is less likely to shift back and forth, left and right.

[0050] (6) Also, the anti-sway support 60 has a first arm 60a extending in one direction and a second arm 60b extending in the other direction with reference to the position of the fastening screw 62, and the first arm 60a and the second arm 60b are formed to have different lengths. In this way, it is difficult to misalign the mounting direction of the anti-sway support 60, and the fastening screw 62 is positioned closer to the side of the vehicle, making the operation easier.

[0051] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not deviate from the gist of the present invention are included in the present invention.

[0052] For example, in the embodiment, the inclined guide portion 2 has been described as trapezoidal or Mount Fuji-shaped in side view, but it is not limited to this, and it can also be a deformed shape in which the center of the upper base portion (top portion) of the trapezoid (Mount Fuji shape) is recessed.

[0053] That is, in the embodiment, since the step ladder 8 is slid in the front - rear direction and the tip of the column 81 of the step ladder 8 is housed in the support 4, the hinge portion 83 of the step ladder 8 is arranged on the left side of the trapezoid in a trapezoidal shape so as to be housed while suppressing the height. On the other hand, in the case of a deformed shape with a concave center, the sliding distance in the front - rear direction can be reduced, or the step ladder 8 can be housed without sliding by changing the support shape. Furthermore, depending on the change in the support shape, it is also possible to make four supports (4).

Explanation of Reference Numerals

[0054] S: Storage structure of step ladder; 1: Rough terrain crane; 10: Traveling body; 10a: Wheels; 11: Outrigger; 2: Tilt guide portion; 21: Mounting portion; 22: Upright portion; 23: Tilt portion; 3: Long hole; 4: Support; 41: Mounting plate; 5: Support member; 60: Anti - sway support; 61: Mounting portion; 62: Set screw (fixing device); 8: Step ladder; 81: Column; 82: Step bar; 83: Hinge portion; 84: Opening stopper portion; 85: Locking portion; 86: Top plate

Claims

1. A storage structure for a jack in a mobile crane, wherein the jack has hinge portions and locking portions on both left and right side surfaces, and the upper surface of the traveling body is provided with a pair of left and right inclined guide portions for guiding a pair of left and right hinge portions and locking portions of the jack in a linearly opened state. A storage structure for a jack.

2. The distance between the deepest portions closest to the upper surface of the traveling body in the pair of left and right inclined guide portions is formed to be substantially the same as the distance between the pair of left and right hinge portions of the jack. The storage structure for a jack according to Claim 1.

3. On the upper surface of the traveling body, inside the pair of left and right inclined guide portions, elongated holes into which protruding portions of the pair of left and right hinge portions of the jack in a linearly opened state are inserted are further provided. The storage structure for a jack according to Claim 2.

4. Slip prevention caps are respectively attached to the tips of the four support columns of the jack, and two supports capable of respectively storing the slip prevention caps at the tips of the support columns of the jack in a linearly opened state are installed on the upper surface of the traveling body. The storage structure for a jack according to Claim 3.

5. The storage structure for a jack according to any one of Claims 1 to 4, further comprising an anti-sway support for suppressing two of the four support columns of the jack, and a fixing device for fixedly attaching / detaching the anti-sway support.

6. The anti-sway support has a first arm extending in one direction and a second arm extending in the other direction with reference to the position of the fixing device, and the first arm and the second arm are formed to have different lengths. The storage structure for a jack according to Claim 5. ​

Images