JP3010488B1 - Safety equipment for aerial work equipment - Google Patents

Abstract

An object of the present invention is to ensure high responsiveness and detection accuracy, always realize reliable detection and quick control to enhance reliability and stability, and to provide a fail-safe function. A movable conductive contact is provided integrally at both ends of a wire formed of a conductive material, and the movable conductive contact is supported to be displaceable and opposed to the movable conductive contact. The fixed-side conductive contacts 5ac are fixedly provided, and the detection mechanism 6 is configured so that the movable-side conductive contacts 5am contact the fixed-side conductive contacts 5ac in a natural state, and between the fixed-side conductive contacts 5ac and 5bc. The power supply unit 7 includes a power supply unit 7 that supplies power, a power supply detection unit 8 that detects a power supply state between the fixed-side conduction contacts 5ac and 5bc, and a control unit 9 that stops and controls the movement of the basket 3 based on the detection result of the power supply detection unit 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for an aerial work machine for protecting a worker on a basket.

[0002]

2. Description of the Related Art Generally, an aerial work machine is provided with a relatively narrow basket supported at the tip of a telescopic boom, and an operator rides on the basket to perform an aerial work or a moving operation. By the way, in such an aerial work machine, when the operator is caught between the basket and another object due to an operation error or the like, the operator has no escape place, so usually,
Elevating machines are equipped with safety devices to prevent such situations.

Conventionally, as a safety device of this type, a wire is provided inside a basket, and movement detecting means such as a limit switch for detecting the movement of the wire when an operator comes into contact with the wire is provided. There is known a safety device that restricts the operation of a boom or a vehicle if the movement of the vehicle is detected (for example, Japanese Utility Model 7-21).
No. 513, etc.).

[0004]

However, the above-mentioned conventional safety device has the following problems.

First, since the movement of the wire is detected by a separately provided movement detecting means such as a limit switch, the control to the safe side is quickly performed by a mechanical delay element existing between the wire and the movement detecting means. Can't do it. In particular, elongation of the wire due to long-term use may directly cause a decrease in responsiveness and may not be detectable.

[0006] Second, the wire is usually placed in a direction perpendicular to the axis by 50 degrees.
Even if the displacement is about mm, the displacement in the axial direction is as small as about 5 mm. Therefore, even a slight mechanical delay element greatly affects the detection accuracy, and a highly reliable and stable detection mechanism cannot be constructed.

Third, if the wire breaks due to damage or the like, the safety device does not function. That is, since the fail-safe function is not exhibited, the original safety cannot be secured.

The present invention has solved the above-mentioned problems in the prior art, and has ensured a high degree of responsiveness and detection accuracy, and has always realized reliable detection and quick control, thereby improving reliability. And dramatically increase stability,
An object of the present invention is to provide a safety device for an aerial work machine that can further enhance safety by having a fail-safe function.

[0009]

According to the present invention, a wire 4 is erected inside a basket 3 supported at the tip of a boom 2, and the displacement of the wire 4 is detected to move the basket 3. When the safety device 1 of the aerial work machine M for controlling the stop of the work is constructed, movable-side conductive contacts 5am and 5bm are integrally provided at both ends of the wire 4 formed of a conductive material, and the movable-side conductive contacts 5am and 5bm are provided. In addition to being displaceably supported, fixed-side conductive contacts 5ac and 5bc opposed to the movable-side conductive contacts 5am and 5bm are fixedly provided, and the movable-side conductive contacts 5am and 5bm naturally contact the fixed-side conductive contacts 5ac and 5bc. Detection mechanism 6 configured to perform
An energizing section 7 for energizing between the fixed-side conductive contacts 5ac and 5bc; an energizing detecting section 8 for detecting an energizing state between the fixed-side conductive contacts 5ac and 5bc; It is characterized by including a control unit 9 for controlling the stop of the movement.

In this case, according to a preferred embodiment, the detecting mechanism 6 includes springs 10a, 10b or springs 10a, 10b for urging both ends of the wire 4 in the axial direction Da tension side, respectively.
Are provided so as to attract both ends to the axial direction Da tension side, respectively, so that the movable-side conductive contacts 5am and 5bm can be brought into contact with the fixed-side conductive contacts 5ac and 5bc in a natural state. Further, the detection mechanism unit 6 includes a combination of a spring 10a for urging both ends of the wire 4 in the axial direction Da tension side and a magnet 11a for attracting the movable-side conductive contact 5am to the fixed-side conductive contact 5ac. Can also be provided.

With the safety device 1 described above, the movable-side conductive contacts 5a are connected to the fixed-side conductive contacts 5ac and 5bc in a natural state.
m and 5bm are in contact with each other, so that one of the fixed-side conductive contacts 5a
c and the other fixed-side conductive contact 5bc are electrically connected to each other.
When power is supplied from the power supply, a current flows through the wire 4 formed of a conductive material. On the other hand, if the worker contacts the wire 4 and the wire 4 is displaced in the direction perpendicular to the axis, one or both ends of the wire 4 are displaced in the axial direction, and at the same time, this displacement is caused by the movable-side conductive contacts 5am, The displacement is 5 bm. That is, the displacement of the wire 4 is directly transmitted to the movable-side conductive contacts 5am and 5bm without intervening a mechanical delay element.
m and 5bm are immediately separated from the fixed-side conductive contacts 5ac and 5bc, and the conduction between one fixed-side conductive contact 5ac and the other fixed-side conductive contact 5bc is released. Therefore, the conduction between the fixed-side conductive contacts 5ac and 5bc is in a non-energized state, and this state is detected by the energization detecting unit 8, and the control unit 9 controls the movement of the basket 3 to stop. Even if the wire 4 is broken due to damage or the like, the conduction between the fixed-side conductive contacts 5ac and 5bc is similarly de-energized, so that a fail-safe function controlled to the safe side is exhibited.

[0012]

Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, a schematic structure of a working machine at a height M provided with the safety device 1 according to the present embodiment will be described with reference to FIG.

A traveling machine 50 includes a crawler belt type self-propelled portion 51 and a vehicle body portion 53 supported above the self-propelled portion 51 via a turntable 52. A boom 2 is provided at the front end of the vehicle body 53, and the boom 2 includes a first boom 54 and a second boom 55 that are refractively connected. The second boom section 55 is further configured to be telescopic, and has an arm section 56 at the distal end. Reference numeral 57 denotes a first undulating cylinder for raising and lowering the first boom portion 54, and reference numeral 58 denotes a second undulating cylinder for raising and lowering the second boom portion 55.

A movable bracket 59 is supported at the tip of the arm 56 (the tip of the boom 2) via a horizontal shaft. The movable bracket 59 has an upper bracket piece 60 and a lower bracket piece 61 integrally.
The support portion 3 provided at one end of the basket 3 by a vertical support shaft 62 attached between the lower bracket piece 61 and the lower bracket piece 61.
Support s. Reference numeral 63 denotes an up-and-down oscillating cylinder which is provided between the arm 56 and the movable bracket 59 to maintain the basket 3 horizontally, and 64 is provided between the movable bracket 59 and the basket 3 to support the basket 3 with the support shaft 62 as a fulcrum. It is a left and right oscillating cylinder that makes a turning displacement. On the other hand, the basket 3 is composed of a plurality of frame portions 65... And opens upward, and has an operation portion 66 on one side of the upper end (on the side of the supported portion 3s). Then, the safety device 1 is attached to the basket 3.

Next, the structure of the safety device 1 according to the present embodiment attached to the basket 3 will be specifically described with reference to FIG.

The safety device 1 includes a pair of detection units 12
a and 12b. One of the detection units 12a includes a housing 13a formed in a rectangular parallelepiped shape. A housing 13a accommodates therein a guide block 14a having a guide hole 15a having a circular cross section, and a cylindrical movable side is provided in the guide hole 15a. The conductive contact 5am is slidably mounted in the axial direction. A fixed conductive contact 5ac facing the movable conductive contact 5am is disposed on the rear surface 13ar of the housing 13a. The fixed conductive contact 5ac is connected to the side surface 13as of the housing 13a together with the connection terminal 17a.
Fixed to. Further, a spring 10a is contracted between the movable conductive contact 5am and the front surface 13af of the housing 13a, and the spring 10a is mounted on the front surface 13af.
The opening 16a having a diameter smaller than the diameter of the opening 16a is provided.

Further, one end of a wire member 4a formed of a conductive material is connected to the front end face of the movable conductive contact 5am, and the other end of the wire member 4a is led out through an opening 16a. 18a is the housing 13a
The waterproof cap 18a is gradually narrowed toward the front of the housing 13a to cover the wire member 4a.

The other detection unit 12b is configured similarly to the above-described detection unit 12a. In the drawing, in the detection unit 12b, 4b denotes a wire member, 5bm denotes a movable-side conductive contact, 5bc denotes a fixed-side conductive contact, 10b denotes a spring, 13b denotes a housing, and 17b denotes a connection terminal. The housings 13a and 13b, the guide blocks 14a, and the waterproof caps 18a in each of the detection units 12a and 12b are formed of an insulating material. The above configuration is the detection mechanism 6.

On the other hand, between the connection terminals 17a and 17b, a circuit in which the conduction section 7 and the conduction detection section 8 are connected in series is connected.
The energization detection unit 8 includes a detection resistor 20 connected between the energization unit 7 and the connection terminal 17b, and a voltage detection unit 21 for detecting a voltage across the detection resistor 20.
The output side of the controller 9 controls the movement of the basket 3 to stop.
Connect to

Next, the mounting method and operation of the safety device 1 according to the present embodiment will be described with reference to FIGS.

The safety device 1 is, as shown in FIGS.
It is installed inside the basket 3. The embodiment shows a case in which two sets of safety devices 1 and 1 are prepared and arranged before and after the basket 3, respectively.

First, as shown in FIG. 3, one detection unit 12a is fixedly attached to a frame 65a located at the upper left end, and the other detection unit 12b is fixedly attached to a frame 65b located at the upper right end. Then, the front ends of the detection units 12a and 12b face each other on the same straight line. When the detection units 12a and 12b are fixed, the one wire member 4a and the other wire member 4b are connected in a state of being appropriately tensioned. Thereby, the wire member 4a
And 4b are connected to form a continuous wire 4. in this case,
For example, as shown in FIG. 1, conductive joints 19a and 19b may be attached to the distal ends of the wire members 4a and 4b, respectively, and connected via the joints 19a and 19b. Note that the attachment position of the joints 19a to the wire members 4a can be changed.

On the other hand, the safety device 1 operates as follows.
First, in the natural state shown in FIG.
Due to the urging force of b, the movable-side conductive contacts 5am and 5bm come into contact with the fixed-side conductive contacts 5ac and 5bc, and the wire 4 maintains a tensioned state. Also, one fixed-side conductive contact 5a
c (connection terminal 17a) and the other fixed-side conductive contact 5bc
Power is supplied from the power supply unit 7 between the (connection terminals 17b), and the fixed-side conductive contact 5ac, the movable-side conductive contact 5am, the wires 4,
Since conduction is performed on the path of the movable-side conductive contact 5bm and the fixed-side conductive contact 5bc, the conduction current Id flows through the path.
Then, this state is detected by the energization detecting unit 8 and the control unit 9 determines that the state is normal.

On the other hand, as shown in FIG. 2 (and the phantom line in FIG. 3), when the worker H contacts the wire 4 and the wire 4 is displaced by the distance Lt in the direction perpendicular to the axis Dr, the wire H 4 is displaced in the axial direction Da by a distance Ls, and at the same time, this displacement is caused by the movable-side conductive contact 5am (5
bm). Therefore, the displacement of the wire 4 is directly transmitted to the movable-side conductive contact 5am (5bm) without a mechanical delay element, and the movable-side conductive contact 5am (5bm) is fixed even with a small displacement. Immediately away from the side conductive contact 5ac (5bc), the conduction between the one fixed side conductive contact 5ac and the other fixed side conductive contact 5bc is released. As a result, the fixed-side conductive contacts 5ac and 5b
Since the state is not energized during period c, this state is determined by the energization detecting unit 8.
The movement of the basket 3 is stopped and controlled by the control unit 9. That is, the movement of the boom 2 or the self-propelled part 5
1 is forcibly stopped.

As described above, according to the safety device 1 according to the present embodiment, since there is no mechanical delay element between the wire 4 and the movable conductive contacts 5am and 5bm, high responsiveness and high detection accuracy are achieved. As a result, reliability and stability are dramatically improved by realizing reliable detection and quick control on the safe side at all times. In addition, the elongation of the wire 4 due to long-term use,
Since the wire 4 appears as a slack, the length of the wire 4 may be adjusted periodically or as needed, and there is no possibility that the responsiveness is reduced or the detection becomes impossible.

Moreover, even if the wire 4 is broken due to damage or the like, the conduction between the fixed-side conductive contacts 5ac and 5bc is similarly de-energized, so that a fail-safe function controlled on the safe side is exhibited, and further safety is achieved. The nature is raised,
In addition, the simplification of the structure enables downsizing and cost reduction, as well as durability and failure prevention.

On the other hand, FIGS. 6 and 7 show a modified embodiment. The modified embodiment shown in FIG. 6 uses a magnet 11a instead of the spring 10a in the embodiment of FIG. That is, in the embodiment of FIG. 1, the movable-side conductive contact 5am is urged by the spring 10a to
ac, but in a modified embodiment, the magnet 11a
As a result, the movable-side conductive contact 5am is sucked and brought into contact with the fixed-side conductive contact 5ac. In FIG. 6, reference numeral 11as denotes an attraction plate attached to the magnet 11a to increase the attraction force, and also serves as the fixed-side conductive contact 5ac. Therefore, the movable-side conductive contact 5am (magnetic material) contacts the suction plate 11as, and the connection terminal 17a is connected to the suction plate 11as. In this modified embodiment, when the movable-side conductive contact 5am is separated from the suction plate 11as, it is necessary to cause the movable-side conductive contact 5am to be attracted to the suction plate 11as by a mechanical reset operation. A part of the derived wire member 4a is replaced with a rod member 4as,
What is necessary is just to provide a reset mechanism for connecting the end of the wire member 4a to the connection part 4ac provided at the tip of the rod member 4as. FIG. 6 shows only one detection unit 12a, but the other detection unit 12b has the same configuration.
In FIG. 6, the same parts as those in FIG. 1 are denoted by the same reference numerals, the configuration is clarified, and the detailed description is omitted.

On the other hand, the modified embodiment shown in FIG.
7 shows an embodiment in which the modified embodiment of FIG. 6 and the embodiment of FIG. 1 are combined. Therefore, in terms of configuration, the structure of the embodiment shown in FIG. 1 with the addition of the magnet 11a or the structure of the modified embodiment of FIG. 6 with the addition of the spring 10a is obtained.
Advantages associated with the combination of the spring 10a and the magnet 11a can be obtained. That is, if the tensile force by the wire 4 does not exceed a certain critical point, the movable side conductive contact 5a
Since m does not separate from the fixed-side conductive contact 5ac, for example,
A problem that a part of the worker H touches the wire 4 during the operation and the safety device 1 operates even when no abnormality has occurred can be avoided. FIG. 7 shows only one detection unit 12a as in FIG. 6, but the other detection unit 12b has the same configuration. In FIG. 7, the same parts as those in FIGS. 1 and 6 are denoted by the same reference numerals, to clarify the configuration, and omit detailed description thereof.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment,
The configuration, shape, material, quantity, etc. of the details can be arbitrarily changed, added, or deleted without departing from the gist of the present invention. For example, as the wire 4, a single material formed of a metal conductive material may be used, or a composite material in which a non-conductive wire material and a conductive wire material are combined may be used.

[0031]

As described above, in the safety device for an aerial work machine according to the present invention, the movable conductive contacts are integrally provided at both ends of the wire formed of the conductive material, and the movable conductive contacts are displaceably supported. A detection mechanism configured to fixedly provide a fixed-side conductive contact facing the movable-side conductive contact, and to configure the movable-side conductive contact to contact the fixed-side conductive contact in a natural state;
In order to include a current-carrying unit that conducts electricity between the fixed-side conducting contacts, a current-carrying detection unit that detects a conduction state between the fixed-side conducting contacts, and a control unit that stops and controls the movement of the basket based on the detection result of the current-carrying detection unit, It has a remarkable effect like

[0032] Since there is no mechanical delay element between the wire and the movable-side conductive contact, high responsiveness and detection accuracy are ensured, and reliable detection and quick control to the safe side are always realized, thereby improving reliability. And the stability can be dramatically improved. In addition, it is possible to avoid a problem that the response is deteriorated due to the elongation of the wire or the detection becomes impossible.

The simplification of the structure enables downsizing and cost reduction as well as durability and failure prevention.

Even when the wire is broken due to damage or the like, the conduction between the fixed-side conductive contacts is similarly de-energized.
By exhibiting a fail-safe function controlled on the safe side, it is possible to further enhance safety.

According to a preferred embodiment, if the detection mechanism is provided with a spring for urging both ends of the wire toward the axial tension side and a magnet for attracting the movable conductive contact to the fixed conductive contact, the work is performed. In this way, it is possible to avoid a problem that a part of the worker touches the wire and the safety device operates even when no abnormality occurs.

[Brief description of the drawings]

FIG. 1 is a block configuration diagram including a cross-sectional configuration of a detection unit of a safety device according to a preferred embodiment of the present invention;

FIG. 2 is a sectional configuration diagram of a detection unit showing a state in which a wire of the safety device is displaced;

FIG. 3 is a plan view of a basket provided with the safety device,

FIG. 4 is a side view of a basket provided with the safety device,

FIG. 5 is a side view of an aerial work machine equipped with the safety device,

FIG. 6 is a sectional configuration diagram of a detection unit according to a modified embodiment of the present invention,

FIG. 7 is a sectional configuration diagram of a detection unit according to another modified embodiment of the present invention,

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Safety device 2 Boom 3 Basket 4 Wire 5am ... Movable side conductive contact 5ac ... Fixed side conductive contact 6 Detection mechanism part 7 Current supply part 8 Current supply detection part 9 Control part 10a ... Spring 11a ... Magnet M Working machine at a high place

Claims (4)

(57) [Claims] 1. A safety device for an aerial work machine for arranging a wire inside a basket supported by a tip end of a boom, detecting displacement of the wire, and controlling stop of the movement of the basket. A movable conductive contact is integrally provided at both ends of the formed wire, and the movable conductive contact is supported so as to be displaceable, and a fixed conductive contact facing the movable conductive contact is fixed and provided, in a natural state. A detection mechanism configured to allow the movable-side conductive contact to contact the fixed-side conductive contact; an energizing unit configured to energize between the fixed-side conductive contacts; and an energization detection unit configured to detect an energized state between the fixed-side conductive contacts. And a control unit for stopping and controlling the movement of the basket based on a detection result of the energization detection unit. 2. The safety device for an aerial work machine according to claim 1, wherein the detection mechanism includes springs for urging both ends of the wire toward the tension side in the axial direction. 3. The safety device for an aerial work machine according to claim 1, wherein the detection mechanism includes a magnet that attracts both ends of the wire to an axial tension side. 4. The detection mechanism section includes a spring that urges both ends of the wire toward an axial tension side and a magnet that attracts the movable conductive contact to the fixed conductive contact. Item 2. The safety device for an aerial work machine according to item 1.