JP7547962B2 - Aerial work platform - Google Patents

Description

The present invention relates to aerial work vehicles.

In high-altitude work vehicles, the load of the basket is detected in order to calculate the working radius. For example, Patent Document 1 discloses a configuration in which the floor plate of the basket is supported by four load cells. With this configuration, the actual load of the basket can be detected, so the working radius can be calculated with high accuracy.

Japanese Utility Model Application Publication No. 5-86996

When the basket is supported by a load cell, as in Patent Document 1, the entire load acting on the basket must be borne by the load cell. Therefore, ensuring safety at the fastening portion between the load cell and the basket is important. For example, when the load cell and the basket are fastened with a bolt, it is assumed that safety will be ensured in the event that the bolt loosens during use. However, Patent Document 1 does not specifically state how to attach the load cell.

The present invention aims to provide an aerial work vehicle that can ensure safety by supporting the basket with a load cell.

The aerial work vehicle of the present invention comprises a boom that is extendable, foldable and rotatable, a vehicle section that movably supports the boom, a basket frame provided at the tip of the boom, a plurality of load cells provided on the upper surface of the basket frame, a basket arranged above the plurality of load cells, a support member having a hole that penetrates in the vertical direction, arranged between the load cell and the basket and fixed to the underside of the basket, a bolt that is inserted into the hole from above and fastened to the load cell, and a ring-shaped member that connects the basket frame and the basket with a gap between them .

According to the above configuration, if the bolt becomes loose due to vibration or the like, the head of the bolt abuts against the underside of the basket before the bolt is unscrewed from the load cell. Therefore, even if the bolt becomes loose, it will not fall off, so the basket can be prevented from falling off the basket frame, and safety can be ensured. In addition, since there is a gap between the basket frame and the basket, the detection result of the load cell is not affected. And, even if all the bolts fastening the basket and the load cell break, it is possible to temporarily prevent the basket from falling off the basket frame, and safety can be ensured.

The above-mentioned high-altitude work vehicle may also be provided with a control unit that calculates the workable range from the sum of the loads detected by the multiple load cells.

According to the above configuration, by using the actual weight of the basket calculated from the detection value of the load cell to calculate the workable range, the workable range can be expanded under light loads compared to when the rated load of the basket is used.

The above-mentioned aerial work vehicle may also be equipped with a boom-raising cylinder for raising and lowering the boom, and a sensor for detecting the load applied to the boom-raising cylinder, and the control unit may calculate the weight of the basket from the detection value of the sensor, and if the weight and the sum of the loads detected by the load cell deviate by a predetermined value or more, determine that the load cell or the sensor is faulty.

With the above configuration, the weight of the basket is detected by two different detection means, making it possible to discover if one of the detection means is malfunctioning.

The present invention makes it possible to realize a high-altitude work vehicle that can ensure safety by supporting the basket with a load cell.

1 is a side view showing an overall configuration of an embodiment of a high altitude work vehicle. FIG. 2 is a perspective view of the basket and its periphery in FIG. 1 . FIG. 2 is a plan view of the basket and its surroundings in FIG. 1 . FIG. 2 is a bottom view of the basket periphery of FIG. 1 . FIG. 2 is a rear view of the basket and its periphery in FIG. 1 . FIG. 2 is a side view of the basket periphery of FIG. 1 . This is a cross-sectional view taken along line AA in FIG. 6. This is a cross-sectional view taken along line B-B of FIG. This is a cross-sectional view taken along the line CC of FIG. FIG. 9 is an exploded perspective view of the load detection device of FIG. 8 . FIG. 2 is a perspective view of the basket and its periphery in FIG. 1 . FIG. 2 is a block diagram showing a part of a control configuration of the aerial work vehicle according to one embodiment.

In the following description, the front-back, left-right, and up-down directions are defined as shown in Figure 1.

[Overall configuration of the aerial work platform]
As shown in Fig. 1, the vehicle for high-altitude work 1 is mainly composed of a vehicle section 2 and a working device 3. The vehicle section 2 supports the working device 3, and is equipped with a pair of left and right front wheels 21 and rear wheels 22. The vehicle section 2 also has outriggers 23 that are grounded to provide stability when working at high altitudes.

The working device 3 includes a boom 31, a basket frame 4 attached to the tip of the boom 31, and a basket 5 supported from below by the basket frame 4. The boom 31 is configured to be extendable, hoistable, and rotatable. The boom 31 is hoisted by a hoisting cylinder 32.

The basket frame 4 and basket 5 are capable of panning, tilting, swinging, and other movements relative to the boom 31. In this embodiment, the basket frame 4 is configured to be L-shaped in a side view, with a lower frame 41 and a rear frame 42. There are no particular limitations on the shape of the basket frame 4, and it may be any shape that can support the basket 5 from below. The basket frame 4 is preferably made of iron to ensure rigidity.

The basket 5 has a substantially rectangular floor 51 and a cage-shaped guard 52 that is configured by assembling multiple rod members in a lattice pattern on the floor 51. From the viewpoint of weight reduction, the basket 5 is preferably made of aluminum, and from the viewpoints of cost, strength, and maintainability, it is preferably made of iron or FRP (Fiber Reinforced Plastics).

As shown in FIG. 2, the basket 5 is supported by the basket frame 4 via the load detection devices 6, and is not in contact with the basket frame 4 at any other portion. The load detection devices 6 are devices that detect the load of the basket 5, and four load detection devices 6 are provided in this embodiment. There is no particular limit to the number of load detection devices 6, so long as multiple load detection devices 6 are provided. There is also no particular limit to the placement of the load detection devices 6, but from the viewpoint of supporting the basket 5 and accurately detecting the load of the basket 5, it is preferable to place them at positions spaced apart from each other and evenly spaced apart.

[Load detection device]
2 to 10, the load detection device 6 includes a load cell 61 that detects the weight of the basket 5 (including the load applied to the basket 5), a support member 62, and a bolt 63. As shown in Fig. 8, the load cell 61 has two holes 611 formed on one end in the left-right direction and penetrating in the up-down direction, and a hole 612 formed on the other end in the left-right direction and penetrating in the up-down direction. The hole 612 is composed of a screw hole 612A penetrating the lower surface of the load cell 61, and a countersunk hole 612B that communicates with the upper end of the screw hole 612A and penetrating the upper surface of the load cell 61.

The load cell 61 is provided on the upper surface of the lower frame 41 of the basket frame 4. Specifically, two bolts 64 are inserted into holes 611 and screwed into mounting parts 411 that form the upper surface of the lower frame 41, thereby fixing the load cell 61 to the upper surface of the basket frame 4. The load cell 61 may be fixed to the lower frame 41 by fixing means other than the bolts 64. The load cell 61 is electrically connected to a control unit (described later) by wiring (not shown).

A load cell using a strain gauge and a strain element that distorts in proportion to stress can be used as the load cell 61. In this embodiment, a square beam type load cell is used as the load cell 61, but other types of load cells may also be used.
is.

10, the support member 62 has a plate-shaped portion 621 having a substantially rectangular shape extending horizontally, holes 622 formed at the four corners of the plate-shaped portion 621 and penetrating in the vertical direction, an engagement portion 623 protruding downward from the center of the plate-shaped portion 621, a hole 624 penetrating the plate-shaped portion 621 and the engagement portion 623 in the vertical direction, and a rotation prevention portion 625 protruding downward from the lower surface of the plate-shaped portion 621. The engagement portion 623 may have any shape that fits into the countersunk hole portion 612B, and is configured to be cylindrical in this embodiment. The length of the engagement portion 623 is configured to be longer than the depth of the countersunk hole portion 612B. The rotation prevention portion 625 is configured at a position and length such that one side surface abuts against one side surface of the load cell 61. The support member 62 is preferably made of iron in order to ensure rigidity.

The support member 62 is assembled to the load cell 61 from above. At this time, the engagement portion 623 is fitted into the countersunk hole portion 612B, and the support member 62 is rotated so that one side of the rotation prevention portion 625 abuts against one side of the load cell 61. The support member 62 is positioned by the rotation prevention portion 625 abutting against the load cell 61. Next, the bolt 63 is inserted from above into the hole portion 624 and screwed into the screw hole portion 612A of the load cell 61, thereby fixing the support member 62 to the upper surface of the load cell 61.

Next, as shown in FIG. 8, the support member 62 is attached to the underside of the basket 5. At this time, the basket 5 is placed so that the mounting parts 511 constituting the underside of the basket 5 abut the upper surface of the support member. The mounting parts 511 are a pair of plate-like members fixed to the floor beams 512 of the basket 5. Then, bolts 65 are inserted from above into the four holes 511A of the mounting parts 511 that overlap with the four holes 622 of the support member 62, and double nuts 66 are tightened from the underside of the plate-like parts 621. This fixes the basket 5 to the upper surface of the support member 62.

In this way, the support member 62 is disposed between the load cell 61 and the basket 5. In this state, the thickness of the mounting portion 511 is greater than the thickness of the head 63A of the bolt 63. Therefore, a gap G is created between the head 63A of the bolt 63 and the floor beam 512 of the basket 5 located directly above it. This gap G is configured to be smaller than the length L of the portion of the threaded portion 63B of the bolt 63 that is screwed into the threaded hole 612A of the load cell 61 and the portion that protrudes downward from the threaded hole 612A.

As a result, if the bolt 63 loosens due to vibration or the like, the head 63A of the bolt 63 comes into contact with the floor beam 512 of the basket 5 before the bolt 63 is unscrewed from the load cell 61. Therefore, the bolt 63 will not fall off even if it loosens, so the basket 5 can be prevented from falling off the basket frame 4, ensuring safety.

In addition, because the engagement portion 623 of the support member 62 is fitted into the countersunk hole portion 612B of the load cell 61, when a lateral load is applied to the basket 5, the load is applied from the engagement portion 623 to the countersunk hole portion 612B, suppressing the shear force applied to the bolt 63. This prevents the bolt 63 from breaking.

[Configuration for preventing basket from falling off]
As shown in Fig. 11, the basket 5 is connected to the basket frame 4 via U-bolts 7. In this embodiment, four U-bolts 7 are provided on the upper frame 42 of the basket frame 4, and surround the guard 52 of the basket 5 at a predetermined interval (e.g., several mm). There is no particular limit to the number of U-bolts 7, and it is sufficient that there is one or more. Note that the U-bolts 7 may be provided on the basket 5 and disposed so as to surround the basket frame 4 at a predetermined interval.

In this way, by providing the U-bolts 7 that connect the basket frame 4 and the basket 5 with a gap between them, the detection results of the load cell 61 are not affected. And even if all of the bolts 63 fastening the basket 5 to the load cell 61 break, it is possible to temporarily prevent the basket 5 from falling off the basket frame 4, ensuring safety.

Note that, as long as the member connects the basket frame 4 and the basket 5 with a gap therebetween, a member other than the U-bolt 7 may be used, such as a circular or elliptical ring member, or a rectangular or triangular ring member.

[Control using load detection device]
12, the vehicle for high altitude work 1 is equipped with a sensor 81, an operation control unit 82, an alarm unit 83, a display 84, and a control unit 85. The sensor 81 is a load sensor that detects the load acting on the hoisting cylinder 32. The weight of the basket 5 can be roughly calculated from the detection value of the sensor 81.

The operation control unit 82 is composed of a control device such as a CPU (Central Processing Unit) and controls the operation of the work equipment 3 such as the boom 31 and basket frame 4. The alarm unit 83 is composed of a sound emitting device such as a speaker or bell and notifies the operator of the status of the aerial work vehicle 1, such as warnings, by voice. The display 84 is composed of a display device such as a liquid crystal panel and displays information about the aerial work vehicle 1, such as the workable range, to the operator.

The control unit 85 is composed of a control device such as a CPU and a storage device such as a RAM (Random Access Memory) or a ROM (Read Only Memory), and the storage device stores performance data related to the work, such as the workable range for the weight of the basket 5. The control unit 85 controls the operation control unit 82, the alarm unit 83, the display 84, etc. based on signals and performance data input from detection devices such as the load cell 61 and the sensor 81.

Here, the control using the load detection device 6 among the controls of the control unit 85 will be described. First, the control unit 85 calculates the workable range using the detection values of each load cell 61 and displays it on the display 84. Specifically, the control unit 85 calculates the weight of the basket 5 by adding up the detection values of each load cell 61. The weight of the basket 5 calculated here includes all loads on the basket 5, such as the operator on the basket 5 and the tools hung on the guard 52. Next, the control unit 85 extracts the workable range corresponding to the calculated weight of the basket 5 from the stored performance data. Then, the control unit 85 displays the extracted workable range on the display 84. This allows the operator to move the basket 5 by referring to the workable range displayed on the display 84.

In this way, by using the actual weight of the basket 5 calculated from the detection value of the load cell 61 to calculate the workable range, the workable range can be expanded under light loads compared to when the rated load of the basket 5 (the maximum load that can be loaded onto the basket 5) is used.

In addition, if the weight of the basket 5 calculated using the detection value of the load cell 61 exceeds the rated load, the control unit 85 causes the alarm unit 83 to emit an alarm, causes the display 84 to display a warning, and disables the movement operation of the working device 3. This makes it possible to prevent the working device 3 from operating when the basket 5 is overloaded, thereby ensuring safety.

In addition, if the control unit 85 detects a sudden increase in load from the detection value of the load cell 61 while the boom 31 or basket 5 is moving, it stops the movement of the boom 31 or basket 5. This stops the movement if the basket 5 collides with the ceiling of a building, etc., preventing the operator from being pinched between the ceiling and the basket 5, ensuring safety.

The control unit 85 also calculates the weight of the basket 5 from the detection value of the sensor 81, compares this weight with the weight of the basket 5 calculated from the detection value of the load cell 61, and if the two deviate by a predetermined value or more, determines that the load cell 61 or the sensor 81 is faulty, and causes the alarm unit 83 to emit an alarm and displays a warning on the display 84. In this way, by detecting the weight of the basket 5 with two different detection means, it is possible to discover if one of the detection means is faulty.

1 Aerial work vehicle 2 Vehicle section 4 Basket frame 5 Basket 7 U-bolt (ring member)
31 Boom 32 Draw-up cylinder 61 Load cell 62 Support member 63 Bolt 81 Sensor 85 Control unit 624 Hole

Claims (3)

A boom configured to be extendable, hoistable, and rotatable;
a vehicle section that movably supports the boom;
A basket frame provided at the tip of the boom;
A plurality of load cells provided on an upper surface of the basket frame;
a basket disposed above the plurality of load cells;
a support member having a hole penetrating in the vertical direction, the support member being disposed between the load cell and the basket and fixed to a lower surface of the basket;
A bolt is inserted into the hole from above and fastened to the load cell;
and a ring-shaped member connecting the basket frame and the basket with a gap therebetween. 2. The vehicle for working at height according to claim 1 , further comprising a control unit that calculates a workable range from a sum of loads detected by the plurality of load cells. A boom lifting cylinder for lifting the boom;
A sensor for detecting a load applied to the lifting cylinder,
3. The aerial work platform vehicle according to claim 2, wherein the control unit calculates the weight of the basket from the detection value of the sensor, and if the weight deviates from the sum of the loads detected by the load cell by a predetermined value or more, determines that the load cell or the sensor is faulty.

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