JP5133674B2 - Fall prevention device - Google Patents

Description

  The present invention relates to a fall prevention device used for an aerial work vehicle in which a work device vertically moves up and down.

  An aerial work platform that has a scissor-link lifting device and that can vertically lift a workbench is configured to be able to travel with the lift device extended and the workbench moved to a higher place. For example, a gymnasium It is used for maintenance work of lighting mounted on the ceiling of the building and for putting materials in and out of shelves provided in the warehouse. In such an aerial work vehicle, if the wheel enters a recess or the like with the lifting device raised, the position of the center of gravity may move and the stability may deteriorate. Therefore, when the lifting device is extended, even if a plate-shaped fall prevention plate is placed between the front and rear wheels at the bottom of the vehicle body, even if the wheel hits the depression, the fall prevention plate prevents the wheel from entering the depression. A fall prevention device (also referred to as “pothole protector”) is provided to prevent the center of gravity from moving greatly. Such a fall prevention device is configured to deploy and store the fall prevention plate in accordance with the lifting operation of the lifting device (see, for example, Patent Document 1).

US Patent Application Publication No. 2005/0224290

  The conventional anti-tip device is set so that the clearance between the lower end of the anti-tip plate and the road surface is very small (for example, about 15 mm) in the unfolded state where the anti-tip plate is extended downward. ). For this reason, when an aerial work vehicle is run with the fall prevention plate deployed, for example, when it reaches the top (convex portion) where the inclination angle of the road surface changes, the center of the lower end of the fall prevention plate is Since there is a possibility of being caught on the top of the road surface and causing interference, there is a problem that traveling stability is poor in a state in which the fall prevention plate is deployed.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a tipping prevention device with improved running stability in a deployed state of the tipping prevention plate.

  In order to solve the above-described problem, a fall prevention device according to the present invention is provided on a vehicle body having front and rear wheels and capable of traveling, and raises and lowers a work device (for example, work table 5 in the embodiment). An overturn prevention device used in an aerial work vehicle having an elevating device, comprising a substantially rectangular plate-like overturn prevention plate attached to a lower portion of a vehicle body between front and rear wheels and having a lower end portion positioned close to the ground The overturning prevention plate is configured to have a concave notch at the lower end of the vehicle substantially in the center in the front-rear direction.

  In such a fall-preventing device according to the present invention, the fall-preventing plate is attached so as to be able to swing within a vertical plane extending laterally with respect to the lower portion of the vehicle body, and is pivoted inward to be positioned along the lower surface of the vehicle body. And an operating means for swinging the fall prevention plate to the retracted position and the unfolded position. For example, it is preferable to be configured to include the drive arm 12, the unfolding operation unit 14, and the storage operation unit 15) in the embodiment.

  Moreover, it is preferable that the notch part of a fall prevention plate is formed in the trapezoid shape opened to a lower end part side in side view.

  Furthermore, it is preferable that the notch portion of the fall prevention plate is formed with an opening having a size that allows the pawl of the forklift to be inserted in the vehicle body width direction.

  According to the fall prevention device according to the present invention, even when the clearance between the lower end portion of the fall prevention plate and the road surface is very small in the unfolded state in which the fall prevention plate is extended downward, the fall prevention plate Since the notch portion is provided at the center of the lower end, it is possible to prevent interference between the lower end portion of the fall prevention plate and the road surface, and to improve running stability.

  In addition, the notch portion of the fall prevention plate is formed with an opening having a size that allows the forklift pawl to be inserted in the vehicle body width direction, so that the fall prevention plate is deployed in a state where the fall prevention plate is deployed. Even when the clearance for inserting the forklift claw between the road surface and the road surface is not secured, the forklift claw can be inserted into the notch to lift the vehicle body. Therefore, the vehicle body can be lifted and moved by the forklift with the fall prevention plate deployed, and the maintenance of the lower part of the vehicle body can be repaired in the lifted state, thereby improving maintainability.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, the configuration of an aerial work vehicle to which the fall prevention device according to the present invention is applied will be described with reference to FIGS. 1 and 2. In the following description, the direction of arrow F in FIG. The aerial work vehicle 1 has front and rear wheels 3a and 3b on the left and right sides of the front and rear of the vehicle body 2. The front wheel 3a is steered in the left and right direction, and the front wheel 3a is driven by an electric motor (not shown). It is configured to be possible. A scissor-link lifting device 4 is mounted on the vehicle body 2, and a work table 5 for operator boarding is mounted on the scissor-link lifting device 4.

  As shown in FIG. 2, the scissor-link type lifting device 4 includes a scissor link 6 in which a plurality of arm members 6 a to 6 h are swingably coupled to form a link mechanism, and a lifting cylinder 7 that expands and contracts the scissor link 6. It consists of. The scissors link 6 has a lower end of the first-stage front arm member 6a that is swingably connected to the vehicle body 2 at a lower portion, and a lower end of the rear arm member 6b is a roller member or slider member (not shown) and a slide rail. Thus, the vehicle body 2 is slidable in the vehicle front-rear direction and is swingably coupled to the vehicle body 2. In addition, the scissor link 6 has an upper end of the fourth stage rear arm member 6h pivotably connected to the work table 5 at an upper portion, and an upper end of the front arm member 6g is connected to a roller member or a slider member (not shown). The slide rail is slidable in the vehicle front-rear direction and is swingably connected to the work table 5. A first bracket 8 is attached to the first-stage front arm member 6a, and a second bracket 9 is attached to the third-stage front arm member 6e. The cylinder portion and the rod portion of the elevating cylinder 7 are attached to the second brackets 8 and 9, respectively.

  The work table 5 is provided with an operation device 5a. When an operator who has boarded the work table 5 operates the operation device 5a, the lifting cylinder 7 is expanded and contracted to expand and contract the scissor link 6. The work table 5 can be lifted vertically to any height to perform work at a height. Further, by operating the operating device 5a, the front wheel 3a can be driven and the front wheel 3a can be steered, and the aerial work vehicle 1 can be driven even when the work table 5 is moved to a high place. it can.

  On both the left and right sides of the vehicle body 2, an anti-tip plate 11 that constitutes a part of the anti-tip device 10 is disposed between the front and rear wheels 3 a and 3 b and between the vehicle body 2 and the ground so as to be unfoldable and retractable. ing.

  Now, a preferred embodiment of the fall prevention device according to the present invention will be described with reference to FIGS. As shown in FIG. 3, the fall prevention device 10 includes a pair of left and right fall prevention plates 11 attached to the vehicle body 2, a pair of left and right drive arms 12, a deployment operation unit 14, and a scissor link type lifting device 4. The retracting operation unit 15 is attached to the first bracket 8.

  The fall prevention plate 11 is formed of an elongated rectangular plate-like member extending in the vehicle front-rear direction, and extends from the lower end portion to the approximate center in the short direction as shown in FIG. A trapezoidal notch 20 is formed in a side view. Inside the fall prevention plate 11, there are a pivoting portion 11a extending upward and a swinging portion 11b extending inward. As for this fall prevention plate 11, the pivot part 11a is attached to the board attachment part 2a formed in the lower part of the right-and-left both sides of the vehicle body 2 so that rocking | fluctuation is possible. The swinging portion 11b is formed with a cylindrical protrusion 11c that protrudes in the vehicle front-rear direction. As shown in FIG. 2, the fall prevention plate 11 is disposed adjacent to the front and rear wheels 3a and 3b, and the short side direction is substantially perpendicular to the ground with the pivoting portion 11a as a swing axis. And a retracted position extending in a substantially horizontal direction in which the lateral direction is substantially parallel to the ground. The fall prevention plate 11 is arranged such that the clearance between the lower end surface of the fall prevention plate 11 and the ground is within a predetermined range when in the unfolded position.

  The drive arm 12 is formed in an elongated plate shape, and a pivot hole 12a is formed on the inner side of the central portion in the longitudinal direction. The pivot hole formed in the pivot hole 12a and the drive arm mounting portion 2b of the vehicle body 2 is formed. The pair of left and right drive arms 12 are arranged in a C shape when viewed from the front. A guide hole 13 penetrating in the vehicle front-rear direction is formed on the outer side of the drive arm 12. The guide hole 13 includes a first guide hole 13 a extending in the longitudinal direction of the drive arm 12 and the first guide hole. The second guide hole 13b is bent from the outer end of 13a and extends upward (short direction). That is, the guide hole 13 is formed in an L shape when viewed from the front. The protrusion 11c of the above-described overturn prevention plate 11 is slidably inserted along the guide hole 13 and attached to the guide hole 13. In addition, a head portion 12b to which a roller formed of hard rubber or the like is rotatably attached is provided at the inner end of the drive arm 12.

  Below the head portion 12b of the drive arm 12, a deployment operation unit 14 is provided. The deployment operation unit 14 is slidably attached to the deployment side attachment unit 2c of the vehicle body 2 in the vertical direction. The deployment side shaft member 14a, the plate-shaped deployment side pressing member 14b fixed to the upper end of the deployment side shaft member 14a, and the deployment side shaft member 14a between the deployment side mounting portion 2c and the deployment side pressing member 14b. It is comprised from the expansion | deployment side spring 14c which is attached so that it may wind around and pushes up the expansion | deployment side press member 14b upwards. A stopper is provided at the lower end of the development side shaft member 14a, and the development side shaft member 14a is configured not to be detached from the development side mounting portion 2c. The upper surface of the development side pressing member 14b is in contact with the lower end of the head portion 12b of the drive arm 12, and is arranged so as to push up the head portion 12b.

  On the other hand, as shown in FIG. 5, the storage operation unit 15 includes a mounting bracket 15a attached to the first bracket 8 of the scissor link type lifting device 4, a storage-side shaft member 15b extending downward from the mounting bracket 15a, and a storage side. A plate-like storage-side pressing member 15c that is slidably attached to the shaft member 15b, and is attached so as to be wound around the storage-side shaft member 15b between the mounting bracket 15a and the storage-side pressing member 15c. The storage side spring 15d pushes the storage side pressing member 15c downward. A stopper (not shown) is provided at the lower end of the storage-side shaft member 15b so that the storage-side pressing member 15c does not come off from the storage-side shaft member 15b. The storage-side shaft member 15b is disposed so as to extend substantially vertically downward from the first bracket 8 when the elevating cylinder 7 is in a fully contracted state, that is, when the scissor link 6 is in the stored state, and In this state, the lower surface of the storage-side pressing member 15c is disposed so as to abut on the upper end of the head portion 12b of the drive arm 12 and push down the head portion 12b. That is, in this state, as shown in FIG. 6, the head portion 12 b of the drive arm 12 is pushed downward by the storage side pressing member 15 c of the storage operation portion 15, and as a result, the expansion side pressing member of the expansion operation portion 14. The configuration is such that 14b is pushed downward to compress the expansion side spring 14c (in the following description, this state is referred to as a “stored state”).

  When the overturn prevention device 10 is in the retracted state, the head portion 12b of the drive arm 12 is pushed downward as described above, and thus the outer portion of the drive arm 12 is swung upward. Therefore, the swinging part 11b is pulled upward via the protrusion 11c of the fall prevention plate 11 inserted in the guide hole 13, and as a result, the short side direction of the fall prevention plate 11 is substantially horizontal and substantially parallel to the ground. Located in the extended storage position. At this time, the protruding portion 11 c of the fall prevention plate 11 is located in the first guide hole 13 a constituting the guide hole 13 of the drive arm 12. When the fall prevention plate 11 is in the retracted position in this way, the fall prevention plate 11 is stored along the lower surface of the vehicle body 2, so that a clearance between the lower surface of the vehicle body 2 and the ground is ensured. The fall prevention device 10 does not hinder normal traveling of the aerial work vehicle 1.

  Next, the expansion | deployment operation | movement of the fall prevention apparatus 10 is demonstrated. When the operating device 5a provided on the workbench 5 is operated and the elevating cylinder 7 starts to extend, the scissor link 6 extends, whereby the storage operating portion 15 moves upward. The head 12b of the drive arm 12 is subjected to a force that pushes upward by a deployment side spring 14c that constitutes the deployment operation unit 14. Therefore, as the storage operation unit 15 rises, The head portion 12b is pushed upward, whereby the outer portion of the drive arm 12 is swung downward.

  When the outer portion of the drive arm 12 is swung downward, as shown in FIG. 7A, the protrusion 11c of the fall prevention plate 11 inserted into the guide hole 13 faces the first guide hole 13a outward. While sliding, the swing part 11b swings downward, and as a result, the fall prevention plate 11 swings downward. Then, as shown in FIG. 7B, when the protrusion 11c reaches the outer end of the first guide hole 13a, the short side direction of the fall prevention plate 11 is located at the unfolded position extending substantially vertically downward to the ground. To do. Further, as shown in FIG. 7C, when the retracting operation portion 15 is raised, the head portion 12b of the drive arm 12 is further pushed upward, and the protruding portion 11c of the fall prevention plate 11 is engaged with the second guide hole 13b. In this case, the fall prevention plate 11 is fixed at the deployed position (in the following description, this state is referred to as “deployed state”).

  As described above, when the elevating cylinder 7 is extended and the scissor link elevating device 4 is extended, the tipping prevention plate 11 of the tipping prevention device 10 is automatically deployed to the deployed position. Even if the work vehicle 1 travels and the wheels 3a and 3b try to enter the recess, the center of gravity moves greatly in order to prevent the wheels 3a and 3b from entering the recess due to the fall prevention plate 11 coming into contact with the ground. There is no.

  By the way, when the aerial work vehicle 1 is in the unfolded state, the clearance between the lower end portion of the fall prevention plate 11 and the ground is small, so that the aerial work vehicle 1 ′ having the conventional fall prevention device 10 ′ travels. In some cases, when the inclination angle of the road surface on the traveling front side changes, there is a problem in that traveling stability is impaired due to the center of the lower end of the fall prevention plate 11 'being caught on the top of the road surface.

  Specifically, when the aerial work vehicle 1 'is traveling on the road surface in the direction of arrow F as shown in FIG. 10A, the inclination angle of the road surface may change to the front side in the traveling direction. is there. As shown in FIG. 10 (b), the wheel (front wheel) 3a 'travels over the top of the road surface where the inclination angle of the road changes, and the approximate center of the aerial work vehicle 1' in the front-rear direction is the top. As shown in FIG. 10C, the lower end central portion of the fall prevention plate 11 ′ interferes with the top portion as shown in FIG. For this reason, the running stability of the aerial work vehicle 1 ′ is impaired.

  Therefore, in order to prevent interference with the road surface, the tipping prevention plate 11 is formed with a notch 20 that opens at the lower center portion as described above. For this reason, when the aerial work vehicle 1 is traveling on the road surface, even if the inclination angle of the road surface changes to the traveling front side, as shown in FIG. Since it does not interfere with the plate 11, the running stability of the aerial work vehicle 1 is not impaired.

  Since the notch 20 is formed only at substantially the center in the vehicle front-rear direction, the front and rear lower ends of the fall prevention plate 11 located in the vicinity of the wheels 3 a, 3 b are the ground even if the wheels 3 a, 3 b try to enter the recess. And the wheels 3a and 3b can be prevented from entering the recess. Therefore, even if the notch 20 is formed in the fall prevention plate 11, the wheels 3a and 3b do not enter the recess.

  In the above-described embodiment, the notch portion 20 of the fall prevention plate 11 is configured to be formed in a trapezoidal shape, but is not limited thereto, and may be a quadrangular shape or the like. The width and height of 20 are also changed according to the specifications of the aerial work vehicle 1.

  Furthermore, as shown in FIG. 9, it is preferable that the notch 20 is formed to have a predetermined width and height so that the pair of claws 21 and 21 provided in front of the forklift can be inserted. Conventionally, when it is necessary to lift the aerial work platform 1 with a forklift or the like during maintenance, when the fall prevention plate 11 is in the unfolded position, the clearance between the lower end of the fall prevention plate 11 and the ground is small. This is because it is difficult to secure a clearance for inserting the forklift claws 21 and 21. For this reason, by forming a notch 20 into which the forklift claws 21 and 21 can be inserted into the fall prevention plate 11, the aerial work vehicle 1 is lifted by the forklift in the fully extended state of the scissor link lifting and lowering device 4 to be moved and maintained. Can do.

  In the above description, the case where the fall prevention device according to the present invention is applied to a vertical lift type aerial work vehicle configured to lift and lower the work table by the scissor link mechanism has been described. The present invention is not limited to an example. For example, a boom type aerial work vehicle that moves a work table to a high place by a boom that is attached to the vehicle body at least to be able to move up and down, or a mast that is attached to be vertically movable up and down. Therefore, the present invention can also be applied to a mast type aerial work vehicle that moves the work table to a high place.

It is a side view of an aerial work vehicle to which the overturn prevention device according to the present invention is applied, and is a view showing a state in which a work table is stored. It is a side view of the aerial work vehicle, and is a view showing a state where the work table is moved upward. It is a principal part enlarged view of the perspective view which shows the structure of the fall prevention apparatus which concerns on this invention. It is a perspective view which shows the fall prevention plate which comprises a part of said fall prevention apparatus. It is a perspective view which shows the storing operation | movement part which comprises a part of said fall prevention apparatus. It is a front view of the said fall prevention apparatus, Comprising: It is a figure which shows a storing state. It is a front view which shows the state by which the said fall prevention apparatus is expand | deployed, Comprising: (a) shows the state in the middle of the fall prevention plate being developed, (b) shows the state by which the fall prevention plate was developed. (C) shows the state where the protrusion of the fall prevention plate and the guide hole of the drive arm are engaged and fixed. It is a side view which shows the state in which the said aerial work vehicle is drive | working the road surface. It is a side view which shows the state which inserted the nail | claw of the forklift into the notch part of the fall prevention plate of the said fall prevention apparatus. It is a side view which shows the state which is driving | running | working the road surface of the aerial work vehicle provided with the conventional fall prevention apparatus, Comprising: (a) shows the state which is drive | working a slope, (b) is a top part of a road surface (C) shows a state where the fall prevention plate interferes with the road surface.

Explanation of symbols

1,1 'Work at height 2 Car body 3a, 3b Front and rear wheels 4 Scissor link lifting device (lifting device)
5 Work table (work equipment)
10, 10 'Fall prevention device 11, 11' Fall prevention plate 12 Drive arm (actuating means)
14 Deployment actuator (actuating means)
15 Storage operation part (operation means)
20 Notch 21 Nail

Claims (4)

A fall prevention device for use in an aerial work vehicle having a vehicle body having front and rear wheels and a lifting device provided on the vehicle body for raising and lowering the work device,
It is attached to the lower part of the vehicle body between the front and rear wheels, and includes a substantially rectangular plate-shaped fall prevention plate whose lower end is located close to the ground,
The fall prevention device, wherein the fall prevention plate is configured to have a concave notch portion at a substantially center in a vehicle longitudinal direction at the lower end portion. The overturn prevention plate is swingably attached in a vertical plane extending left and right with respect to the lower portion of the vehicle body, and is swung inward to be located at the retracted position and along the lower outside of the vehicle body. It is configured to be able to swing and move to a deployment position where the lower end is positioned close to the ground.
The fall prevention device according to claim 1, further comprising an operating unit that swings the fall prevention plate to the retracted position and the unfolded position.   The fall prevention device according to claim 1 or 2, wherein the cutout portion of the fall prevention plate is formed in a trapezoidal shape that opens to a lower end side in a side view.   The fall prevention according to any one of claims 1 to 3, wherein the notch portion of the fall prevention plate is formed with an opening having a size capable of inserting a pawl of a forklift in a vehicle body width direction. apparatus.

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