JP2022109813A - Contact prevention device of telescopic boom - Google Patents

Abstract

To provide a contact prevention device of a telescopic boom capable of accurately and precisely detecting an obstacle, which hinders the movement of the telescopic boom.SOLUTION: A contact prevention device of a telescopic boom includes: a telescopic boom with a base end connected to a base machine to be raised/lowered, rotatable, and extendable/contractible; a boom length measurement device measuring a boom length of the telescopic boom; a measurement region sensor detecting an obstacle existing in a detection region set along the telescopic boom; detection region setting means changing and setting a detection region of the measurement region sensor based on the boom length measured by the boom length measurement device; and telescopic boom operation suppression means receiving an obstacle detection signal from the measurement region sensor to suppress the operation of the telescopic boom.SELECTED DRAWING: Figure 1

Description

The present invention provides a crane having a telescopic boom, an aerial work vehicle, a bridge inspection vehicle, and a telescopic boom of a work vehicle used when inspecting or repairing structural members constituting a structure such as a bridge. Regarding the device.

Since bridges are constantly exposed to the elements, they are regularly inspected and repaired. In particular, bridges are constructed by integrally combining various girder members using connecting members and the like. Furthermore, when a bridge has a truss structure, the girder members are combined in various directions to form a complex structure. structure.

When inspecting or repairing structural members that make up a bridge, cranes with telescoping booms, aerial work platforms, bridge inspection vehicles, and structures that make up structures such as bridges should be placed at the inspection or repair site. A permanent work vehicle (hereinafter collectively referred to as "work vehicle") used when inspecting or repairing members is arranged, and the telescopic boom provided on this work vehicle is expanded and contracted while raising and lowering and turning, While moving (horizontally) the work vehicle as necessary, avoiding structural members such as girder members and connecting members, and working floors such as cages, buckets, and decks provided at the tip of the telescopic boom, and equipment such as inspection equipment ( hereinafter collectively referred to as "working member") is brought to an inspection or repair place to perform inspection or repair work.

On the other hand, when operating the telescopic boom and work floor of the work vehicle, there are obstacles such as girder members and connection members connecting these girder members, and it is dangerous if the telescopic boom and work floor collide with these obstacles. Therefore, care must be taken to prevent objects from colliding with the telescopic boom and work floor.

In Patent Document 1, a transmission signal is output to the vicinity of the boom of a crane, and the transmission signal hits an obstacle within a reception range set in at least a part of the vicinity of the boom, and the received signal is reflected. and detecting the time difference between the transmitted signal and the received signal, calculating an amount related to the distance between the obstacle and the boom based on the detected time difference, and setting the calculated amount in advance. Crane boom collision alarm methods have been proposed which provide an alarm when the load is below a set alarm set point.

Patent Document 2 discloses a worker protective device installed on a work bucket that moves to a work position with a worker on it, and is installed on the work bucket to detect that the work bucket approaches a structure. an ultrasonic sensor, a warning device that issues a warning to the worker, and the warning device that issues a warning when the ultrasonic sensor detects that the work bucket has approached a structure. A worker protective device has been proposed that has a control device that controls the

Patent Document 3 discloses a tool attached to a pole installed on a workbench capable of moving up and down and in the horizontal direction of an aerial work vehicle, in which a rod-shaped main body equipped with a tilt detection sensor can be tilted freely. a light emitting means and a buzzer are provided on the main body, and each operation of the light emitting means and the buzzer is associated with the tilt detection sensor; and the mounting member. A safety for aerial work vehicle, in which a road surface irradiation laser for detecting the traveling lane is attached to a position protruding outward from the aerial work vehicle, and each operation of the light emitting means and the buzzer and the road surface irradiation laser are associated with each other. equipment is proposed.

JP-A-7-112893 JP 2020-83483 A JP 2018-70331 A

However, in Patent Document 1, an ultrasonic pulse is used as the transmission signal. Obstacle detection methods using ultrasonic pulses have a problem that detection accuracy is low and detection speed is low, and obstacles cannot be detected accurately and quickly.

The obstacle detection method using ultrasonic pulses in Patent Document 1 can only detect obstacles at a distance of about 10 m at the longest, and detects obstacles at a distance greater than that. I can't. Therefore, inspection or repair locations for structural members of large bridges cannot be used in many cases exceeding 10m from the ground.

In addition, the working member attached to the tip of the telescopic boom must be as close to the inspection or repair place as possible, and the method of detecting obstacles using ultrasonic pulses is not suitable for inspecting or repairing places. There is a problem that an object may be erroneously detected, inspection or repair work is interrupted, and efficient work cannot be performed.

The worker protection tool disclosed in Patent Document 2 uses an ultrasonic sensor to detect the approach of a structure to a work bucket, and the detection range of obstacles is limited to the vicinity of the periphery of the bucket. Since the telescopic boom has a plurality of nested booms, a sensor cannot be attached to the telescopic boom, and an obstacle approaching the telescopic boom cannot be detected. In addition, as with the crane boom collision warning method of Patent Document 1, there is a risk of erroneously detecting an object to be inspected or repaired. There is a problem that mounting is required, the cost is increased, and the arrangement of the ultrasonic sensor is complicated.

The safety equipment for high-altitude vehicles disclosed in Patent Document 3 detects a collision with an obstacle using a contact-type tilt sensor, and the obstacle detection range is limited to the vicinity of the periphery of the workbench. Furthermore, similarly to the work vehicle protective equipment of Patent Document 2, a sensor cannot be attached to the telescopic boom, and an obstacle approaching the telescopic boom cannot be detected. In addition, when the telescopic boom becomes long, it is necessary to install many ultrasonic sensors and wiring, which raises the cost and complicates the arrangement of the ultrasonic sensors.

It is difficult to limit the detection range of the ultrasonic pulses used in Patent Documents 1 and 2, and there is a possibility of erroneously detecting an obstacle located away from the telescopic boom. There is a problem that it is necessary to interrupt the operation to confirm whether there is an obstacle, and inspection or repair work cannot be carried out smoothly.

SUMMARY OF THE INVENTION The present invention provides a contact prevention device for a telescopic boom that can accurately and accurately detect obstacles that hinder the movement of the telescopic boom. Further, the present invention provides a contact prevention device for a telescopic boom that can accurately and accurately detect obstacles that hinder the movement of working members attached to the tip of the boom.

The telescopic boom contact prevention device is
a telescopic boom whose base end is connected to the base machine so as to be able to hoist, turn, and telescope;
a boom length measuring device for measuring the boom length of the telescopic boom;
a range sensor that detects an obstacle existing within a detection area set along the telescopic boom;
detection area setting means for changing and setting the detection area of the range sensor based on the boom length measured by the boom length measuring device;
telescopic boom operation suppression means for receiving an obstacle detection signal from the range sensor and suppressing the telescopic boom.

According to the present invention, the detection area of a range sensor is changed and set according to the boom length that changes with the extension and contraction of a telescopic boom, and an obstacle existing in the set detection area is accurately and quickly detected by the range sensor. Since it is detected, the presence or absence of an obstacle can always be detected along substantially the entire length of the telescopic boom, and the obstacle can be prevented from colliding with the telescopic boom.

The present invention uses a range sensor for detecting obstacles, and can set a detection area along the telescopic boom. Only objects that can be obstacles to the telescopic boom can be accurately detected as obstacles to avoid collision of the obstacles with the telescopic boom.

Furthermore, if a work member is provided at the tip of the telescopic boom and obstacles to the work member are detected by a contact sensor, obstacles can be detected from the telescopic boom to the work member. can be done with certainty.

The schematic diagram which showed the expansion-contraction state of the telescopic boom. The schematic diagram which showed the expansion-contraction state of the telescopic boom. The figure which showed the functional structure of the contact prevention apparatus of a telescopic boom. The figure which showed the hardware constitutions of the contact prevention apparatus of a telescopic boom. The figure which showed the detection area of the ranging sensor according to the boom length of the telescopic boom. 4 is a flow chart showing the operation of the contact prevention device for the telescopic boom. 4 is a flow chart showing the operation of the contact prevention device for the telescopic boom. 4 is a flow chart showing the operation of the contact prevention device for the telescopic boom. The figure which showed the aspect which the telescopic boom is connected to the base machine via the articulated boom.

An example of a contact prevention device for a telescopic boom according to the present invention will be described with reference to the drawings. As shown in FIG. 1, a contact prevention device A for a telescopic boom comprises a base machine 1 such as a work vehicle, and a telescopic boom 2 connected to the base machine 1 so that its base end can be raised and/or swiveled. ing.

The base machine 1 has an installation surface for arranging the telescopic boom 2, and the telescopic boom 2 is provided so that it can be raised and lowered in the vertical direction and can be turned in the horizontal direction with respect to the installation surface. there is As shown in FIGS. 1 and 2, the telescopic boom 2 includes a base boom 21 connected to the mounting surface of the base machine 1, one or more intermediate booms 22, 22 . A top boom 23 that constitutes the tip of the telescopic boom 2 is telescopically accommodated, and the telescopic boom 2 can be extended and contracted by protruding from the boom on the base end side or immersing in the boom on the base end side. It is The telescopic boom 2 is configured to be raised, lowered, swiveled, and extended and retracted by a general-purpose driving device (not shown). At the tip of the top boom 23 of the telescopic boom 2, a bucket, which is one of working members 23a on which a worker can ride, is integrally provided. 1 and 2 show the case where a bucket is integrally provided at the tip of the top boom 23 of the telescopic boom 2 as an example of the working member 23a, but the invention is not limited to the bucket and the top boom 23 A working floor such as a cage or a deck on which an operator can board or equipment such as an inspection device may be integrally provided at the tip. Examples of working members 23a include working floors such as cages, buckets and decks, and materials and equipment such as inspection devices.

1 shows a case where the telescopic boom 2 is directly connected to the base machine 1, but as shown in FIG. The telescopic boom 2 may be connected via a multi-joint arm M (see FIG. 9) formed by rotatably connecting opposite ends of the arms M1, M1, . . . .

1(a) and 2(a) show the telescopic boom 2 in the most contracted state, and FIGS. The telescopic boom 2 is shown in FIGS. 1(b) and 2(b) between the most retracted and the most extended states.

The telescopic boom 2 is provided with a boom length measuring device 3 for measuring the length of the telescopic boom 2 . The boom length measuring device 3 does not need to measure the total length from the base end to the tip of the telescopic boom 2, and the detection area K of the range sensor 4, which will be described later, can be changed and set according to the boom length of the telescopic boom 2. , as long as the overall length of the telescopic boom 2 can be roughly measured.

For example, the boom length measuring device 3 includes a transmitter 31 that is provided on the lower surface of the base end of the base boom 21 (the vertical direction is defined as the vertical direction) and that emits a laser beam, and a transmitter 31 that is provided near the tip of the top boom 23. and a reflecting plate 32 provided on the base end side by a predetermined length from the working member 23a to reflect the laser light emitted from the transmitter 31. is reflected by the reflector 32, the transmitter 31 measures the time until the signal is received, and the distance between the transmitter 31 and the reflector 32 is measured as the boom length. mentioned. Alternatively, the transmitter 31 may be provided on the top boom 23 and the reflector 32 may be provided on the base boom 21 .

The transmitter 31 is provided at a location that is not displaced by the telescopic boom 2 , that is, at the base end of the base boom 21 . , is provided in the vicinity of the tip of the fluctuating top boom 23, that is, in the portion of the top boom 23 positioned below the working member 23a provided at the tip of the top boom 23 by a predetermined length. In addition, while the reflector 32 is provided at a place where the telescopic boom 2 is not displaced by the telescopic boom 2 , that is, at the base end of the base boom 21 , the transmitter 31 is always placed in the telescopic direction of the telescopic boom 2 by the telescopic boom 2 . It may be provided in the vicinity of the tip of the top boom 23 that fluctuates, that is, in the portion of the top boom 23 positioned below the working member 23a provided at the tip of the top boom 23 by a predetermined length. The boom length measuring device 3 measures the length between the base end of the base boom 21 and the portion of the telescopic boom 2 located a predetermined length below the tip of the top boom 23 as the boom length. The boom length of the telescopic boom 2 is measured so as not to overlook the length change in the telescopic direction of the telescopic boom 2 due to the extension and retraction of the telescopic boom 2 . The measurement range of the boom length measuring device 3 is set so as to always detect the length variation in the telescopic direction of the telescopic boom caused by extension and retraction. The boom length measuring device 3 corrects the measured value by adding the distance between the base end of the base boom 21 and the transmitter 31 to the measured value, and outputs the corrected value as the boom length. You may make it

In addition, as described above, the reflector 32 is disposed below the work member 23a, and is used to swing the work floor (horizontal rotation), to prevent materials and equipment such as inspection devices, and The measurement of the boom length of the telescopic boom 2 by the boom length measuring device 3 is not affected by the operator and the work equipment used by the operator.

Furthermore, the telescopic boom 2 is provided with a range sensor 4 on each side surface of the base end of the base boom 21 in the turning direction (the turning direction is defined as the left-right direction). Note that the range sensor 4 may be provided on each of the surfaces (upper surface and lower surface) in the undulating direction (the undulating direction is defined as the vertical direction) at the base end of the base boom. The range sensor 4 emits a laser beam such as an infrared laser and measures the reflected light reflected by the obstacle to measure the direction and distance of the obstacle, and is also called a laser scanner. The range sensor 4 can specify an obstacle detection area in advance, and when an obstacle exists within the detection area K, outputs an obstacle detection signal indicating the presence of an obstacle.

As shown in FIGS. 1 and 2, the detection area K of the range sensor 4 is set along the side of the telescopic boom 2 in the turning direction in the length direction of the telescopic boom 2 . When a range sensor is provided on the side surface of the base end of the base boom in the hoisting direction (the hoisting direction is defined as the vertical direction), the detection area K of the range sensor 4 extends in the length direction of the telescopic boom 2. 2 along the undulating side. The length of the detection area K of the range sensor (the length of the telescopic boom 2 in the telescopic direction) is set according to the boom length of the telescopic boom in a manner described later. The width of the detection area K of the range sensor 4 (the width of the strip-shaped detection area K shown in FIG. 1) is the widest width of the telescopic boom 2 (the widest width of the telescopic boom 2 in the hoisting direction or the turning direction) or It is preferable to set the width to be slightly wider than this width. The detection area K of the range sensor 4 is a predetermined distance from the side of the telescopic boom 2, taking into account the time lag from the detection of an obstacle by the range sensor 4 to the suppression of the movement of the telescopic boom 2, the movement speed of the obstacle, and the like. It is set at a position separated by a distance.

Further, since the range sensor 4 uses a laser beam, the range sensor 4 points upward as the telescopic boom 2 stands up, but the range sensor 4 is affected by sunlight. Therefore, an obstacle within the detection area K can be detected accurately and quickly. Note that the range sensor 4 may be provided on the side surface of the base end of the base boom 21 in the undulating direction.

As shown in FIG. 3, the telescopic boom contact prevention device A is functionally composed of a base machine 1 such as a working vehicle, a telescopic boom 2, a working member 23a, a contact sensor, and a boom length measuring device. A device 3 , a range sensor 4 , detection area setting means 5 , telescopic boom operation suppression means 6 , and speed comparison means 7 are provided. In FIG. 3, a solid line indicates a physical connection, and a dotted line indicates an electrical connection.

As shown in FIG. 4, the telescopic boom contact prevention device A physically includes a base machine 1 such as a work vehicle, a telescopic boom 2, a working member 23a, a contact sensor, and a boom length measuring device. Device 3, range sensor 4, CPU (Central Processing Unit) 81, ROM (Read Only Memory) 82, RAM (Random Access Memory) 83, auxiliary storage device 84, output module 85 and input module 86 and In FIG. 4, a solid line indicates a physical connection, and a dotted line indicates an electrical connection.

In the CPU 81, the driving device 2a of the telescopic boom 2, the contact sensor, the boom length measuring device 3, the range sensor 4, the ROM 82, the RAM 83, the auxiliary storage device 84, the output module 85 and the input module 86 are A/D if necessary. They are communicatively electrically connected via the conversion element. The CPU 81, the contact sensor, the boom length measuring device 3, the range sensor 4, the auxiliary storage device 84, the output module 85, and the input module 86 are attached or mounted with a general-purpose wireless module to electrically communicate with each other wirelessly. may be connected to A wireless module is a module for wireless data communication, and includes Wi-Fi (registered trademark), Bluetooth (registered trademark), W-CDMA standard, LTE standard, and LPWA. (Low Power Wide Area) is a module for realizing a normal wireless communication system such as the standard.

Examples of the auxiliary storage device 84 include SSDs (Solid State Drives) and HDDs (Hard Disk Drives). Examples of the output module 85 include a display, speaker, mobile terminal device, and the like. Examples of the input module 86 include a keyboard, touch panel, switch, and the like.

The telescopic boom contact prevention device A loads a predetermined program into the CPU 81 and RAM 83 to operate the boom length measuring device 3, the range sensor 4 and the contact sensor under the control of the CPU 81. It is realized by reading and writing data in the RAM 83 and the auxiliary storage device 84 .

Under the control of the CPU 81, the detection area setting means 5, the telescopic boom operation suppression means 6, and the speed comparison means 7 are respectively stored in the ROM 82 and/or the auxiliary storage device 84. A predetermined function is exhibited by executing a suppression program and a speed comparison program.

The boom length of the telescopic boom 2 is always measured by the boom length measuring device 3, and the measured boom length is always transmitted to the CPU81. Then, the CPU 81 sets the detection area K of the range sensor 4 according to the detection area setting program. If there are a plurality of range sensors 4, detection areas K are similarly set for all range sensors 4. FIG. In the following operations, when a plurality of range finding sensors 4 are provided, the following operations are performed independently for each range finding sensor 4 .

In the ROM 82 and/or the auxiliary storage device 84, as shown in FIG. is set and stored in advance.

FIG. 5 shows an example of setting the length of the detection area K of the range sensor 4 according to the boom length of the telescopic boom 2 . In FIG. 5 , the horizontal axis of the graph is the boom length D of the telescopic boom 2 , and the belt extending in the horizontal direction indicates the length of the detection area K of the range sensor 4 . Of the lines extending in the vertical direction, the left line B is the full length of the telescopic boom 2 in the most contracted state.

A determination range J is set by dividing the boom length of the telescopic boom 2, and the length of the detection area K of the range sensor 4 is set for each determination range J. For example, when the boom length D of the telescopic boom 2 is within the determination range J1, which is equal to or greater than D1 and less than D2, the length of the detection area is the length of the area 1 [Figs. )reference]. The boom length D1 is the boom length of the telescopic boom 2 in the most retracted state.

When the telescopic boom 2 is extended and the boom length D of the telescopic boom 2 is within the determination range J2, which is equal to or greater than D2 and less than D3, the length of the detection area K becomes the length of the area 2 [Fig. b) and FIG. 2(b)]. Then, when the telescopic boom 2 is further extended and the boom length of the telescopic boom 2 is within the determination range Jn-1, which is equal to or greater than Dn-1 and less than Dn, the length of the detection area K is the area n-1. [see FIGS. 1(c) and 2(c)].

5 shows a case where the length of the detection area K (length of area n) of the range sensor 4 is matched with the lower limit value of the determination range determined based on the boom length D of the telescopic boom 2. However, it is not necessary to match the length of the detection area of the range sensor 4 (length of area n) to the lower limit of the judgment range determined based on the boom length D of the telescopic boom 2. The length of the detection area K is shorter than the total length of the telescopic boom 2 (the length from the base end to the tip of the telescopic boom 2), and the working member 23a and the worker and the worker who get on the work floor Any range is acceptable as long as it can eliminate misrecognition by the work tool to be used, and it is preferable that the length is as long as possible within such a range.

In this way, the length of the detection area K of the range sensor 4 is preset according to the boom length of the telescopic boom 2, and the longer the determination range determined based on the boom length of the telescopic boom 2, the more The length of the detection area K of the range sensor 4 is set to be long. On the other hand, the length of the detection area K of the range sensor 4 is always set to be shorter than the total length of the telescopic boom 2 (the length from the base end to the tip of the telescopic boom 2).

The length of the detection area K of the range sensor 4 is always set to be slightly shorter than the total length of the telescopic boom 2, and the working member 23a provided at the tip of the telescopic boom 2 is set to the detection area of the range sensor 4. K is always excluded, so that the range sensor 4 does not erroneously recognize the work member 23a provided at the tip of the telescopic boom 2, the worker on the work floor, and the work implement used by the worker. It consists of

Furthermore, according to the extension of the telescopic boom 2, the length of the detection area K of the range sensor 4 is lengthened step by step. It is possible to set the detection area K of the range sensor 4 to a range that can cover most of the total length of the telescopic boom 2 while avoiding erroneous recognition of the range sensor 4 due to the work tool used. 2 can be reliably detected by the range sensor 4 without erroneous recognition. When the range sensor 4 detects an obstacle, the range sensor 4 sends an obstacle detection signal to the telescopic boom operation suppression means 6 to notify that the obstacle has been detected. , the operation of the telescopic boom 2 is entirely stopped, or the operation (movement) of the telescopic boom 2 in the direction approaching the location where the obstacle is detected is suppressed (these are collectively referred to as "movement of the telescopic boom (sometimes referred to as “suppressed”). When the movement (movement) in the direction approaching the detected location of the obstacle is suppressed, the movement of the telescopic boom 2 in the direction away from the detected location of the obstacle is permitted. If necessary, the information may be output to the output module 85 by voice or display to alert the operator of the telescopic boom 2 and/or the worker on the working floor.

In FIG. 5, the boom length of the telescopic boom 2 is divided to set the determination range J, and when the boom length of the telescopic boom 2 belongs to the same determination range J, the length of the detection area K of the range sensor 4 is set to the same length. , and the length of the detection area K of the range sensor 4 was set to increase stepwise (stepwise). may be set to be continuously longer.

Further, it is preferable that the telescopic boom contact prevention device A has a speed comparison means as a safety device. The speed comparison means compares the measured telescoping speed of the telescopic boom 2 with the reference telescoping speed, and when the measured telescoping speed exceeds the reference telescoping speed, the speed comparison means transmits an overspeed signal to the telescopic boom operation suppression means.

The boom length of the telescopic boom 2 is always measured by the boom length measuring device 3, and is always transmitted to the CPU81. Based on the boom length of the telescopic boom 2 transmitted from the boom length measuring device 3, the measured telescopic speed of the telescopic boom 2 is constantly calculated by the speed comparing means 7. The boom length of the telescopic boom 2 is extracted at predetermined time intervals from the boom length of the telescopic boom 2 measured by the boom length measuring device 3, and the boom length extension/retraction speed is calculated as the amount of change in the boom length during the predetermined time. It is calculated by calculating the absolute value and converting the amount of change in the boom length into the amount of change per unit time (for example, per second).

The ROM 82 and/or the auxiliary storage device 84 preliminarily sets and stores a reference expansion/contraction speed. The speed comparison means 7 sends an overspeed signal to the telescopic boom operation suppression means 6 when the measured telescopic speed calculated in the manner described above exceeds the reference telescopic speed.

The boom length of the telescopic boom 2 is always measured by the boom length measuring device 3, but if an obstacle enters the measuring range of the boom length measuring device 3, the telescopic boom 2 will be measured by the boom length measuring device 3. boom length suddenly shortens.

That is, the boom length measuring device 3 measures the distance between the transmitter 31 and the reflector 32, and corrects it as necessary to measure the boom length of the telescopic boom 2. If an obstacle such as a flying object enters between the device 31 and the reflector 32, the laser beam emitted from the transmitter 31 is reflected by the obstacle before being reflected by the reflector 32, resulting in a boom. The boom length of the telescopic boom 2 measured by the length measuring device 3 suddenly becomes shorter than the original boom length, and the telescopic speed of the telescopic boom 2 suddenly increases.

Therefore, the measured telescoping speed is compared with the reference telescoping speed by the speed comparing means 7, and when the measured telescoping speed exceeds the reference telescoping speed (when the measured telescoping speed exceeds the allowable range), the boom length measuring device 3 (an obstacle has approached the telescopic boom 2), an overspeed signal is transmitted to the telescopic boom operation suppression means 6, and the telescopic boom operation suppression means 6 moves the telescopic boom 2. movement is suppressed.

In this manner, by detecting an obstacle approaching the telescopic boom 2 by means of speed comparison means in addition to the range sensor 4, collision of the obstacle with the telescopic boom 2 can be reliably avoided.

Next, the operating procedure of the telescopic boom contact prevention device A will be described. The input module 86 of the telescopic boom contact prevention device A is used to operate the telescopic boom contact prevention device A (step 1). In addition, in FIG. 6, a step is described as "S".

When the telescopic boom contact prevention device A is activated, the boom length measuring device 3 is activated, the boom length of the telescopic boom 2 is constantly measured, and the measured boom length is sent to the CPU 81 (S2).

The relationship between the boom length of the telescopic boom 2 and the length of the detection area K of the range sensor 4 is preset in the ROM 82 and/or the auxiliary storage device 84 using, for example, tables, graphs, calculation formulas, and the like. The length of the detection area K of the range sensor 4 is set by the detection area setting means 5 based on the received boom length of the telescopic boom 2 in accordance with this preset condition. The width of the detection area K of the range sensor 4 is set to a desired width, for example, the width of the base boom 21 of the telescopic boom 2 (dimension in the direction perpendicular to the telescopic direction of the telescopic boom 2) or a width slightly wider than this. is set to

For example, if the relationship between the length of the telescopic boom 2 and the length of the detection area K of the range sensor 4 is determined as shown in FIG. A determination range J is specified based on the length (S3).

For example, when the boom length of the telescopic boom 2 is "D5 or more and less than D6", the detection area setting means 5 selects "J5" as the determination range, and based on this determination range J5, the range sensor 4 "Area 5" is selected as the length of the detection region K of the range sensor 4, and the length of the detection region K of the range sensor 4 is set to "D5" (S4).

In this way, since the length of the detection area K of the range sensor 4 is set according to the boom length of the telescopic boom 2, obstacle detection by the range sensor 4 over substantially the entire boom length of the telescopic boom 2 is possible. is performed (S5).

The working member 23a is always excluded from the detection area K of the ranging sensor 4, and the ranging sensor 4 detects the working member 23a provided at the tip of the telescopic boom 2, the worker riding on the working floor, and the worker. Since it is constructed so as not to erroneously recognize the work implement used as an obstacle, only the obstacle approaching the telescopic boom 2 can be accurately detected by the range sensor 4 .

In addition, as the telescopic boom 2 stands up, the transmitter of the range sensor 4 also points upward, making it easier for the range sensor 4 to receive sunlight. It is not affected by sunlight, and obstacles can be accurately detected regardless of the undulating state of the telescopic boom 2.

Then, when an obstacle enters the detection area K of the telescopic boom 2, the obstacle is detected by the range sensor 4, and an obstacle detection signal is transmitted to the telescopic boom operation suppressing means 6 (S6). Upon receiving the obstacle detection signal, the telescopic boom operation suppressing means 6 completely stops the operation of the telescopic boom 2 or prohibits the telescopic boom 2 from moving in a direction approaching the location where the obstacle is detected. The operation of the boom 2 is suppressed (S7). If necessary, the information may be output to the output module 85 by voice or display to alert the operator of the telescopic boom 2 and/or the worker on the working floor.

When the operation of the telescopic boom 2 is suppressed by the telescopic boom operation suppression means 6, the operator of the telescopic boom 2 checks the surroundings of the telescopic boom 2, removes obstacles approaching the telescopic boom 2, and then the input module 86 is operated. is used to transmit an obstacle removal signal to the telescopic boom operation suppression means. When the telescopic boom operation suppressing means 6 receives the obstacle removal signal, the telescopic boom operation suppressing means 6 cancels the suppression of the operation of the telescopic boom 2, returns to the operation before the obstacle was detected, and then proceeds to step 2. Returning, the contact prevention device of the telescopic boom resumes normal operation before detecting the obstacle.

During bridge inspection and repair work, the telescopic boom 2 is undulated and/or rotated while avoiding structural members such as girder members and connecting members that constitute the bridge, and the work vehicle is moved as necessary. By moving (horizontally) (these operations of the telescopic boom 2 may be collectively referred to as "fluctuation"), the working member 23a provided at the tip of the telescopic boom 2 is made to reach the target work point.

Since the constituent members of the bridge are oriented in various directions, if the telescopic boom 2 is moved to avoid one constituent member, there is a risk of accidental collision with another constituent member. In the telescopic boom contact prevention device, the range sensor 4 constantly monitors obstacles approaching the telescopic boom 2 over substantially the entire length of the telescopic boom 2 regardless of the boom length of the telescopic boom 2 . Collision of an obstacle with the boom 2 can be prevented.

When an obstacle approaching the telescopic boom 2 is detected by the speed comparison means 7 as a safety device together with the detection of the obstacle by the range sensor 4, the telescopic boom 2 measured by the boom length measuring device 3 is detected. Based on the boom length of the telescopic boom 2, the measured telescopic speed of the telescopic boom 2 is always calculated by the speed comparing means 7 (S8). Note that the description of the same operations as those in the flowchart of FIG. 6 will be omitted.

Then, the speed comparison means 7 always compares the preset reference telescopic speed with the measured telescopic speed (S9). An overspeed signal is transmitted to the operation suppression means 6 (S10), and the operation of the telescopic boom 2 is suppressed by the telescopic boom operation suppression means 6 (S7). The output to the output module 85 and the cancellation of the telescopic boom motion suppression by the telescopic boom motion suppression means are the same as those described above, so description thereof will be omitted.

According to the contact prevention device for the telescopic boom, the working member 23a provided at the tip of the telescopic boom 2 is positioned within the detection area of the range sensor 4 in order to prevent the working member 23a from erroneously recognizing the range sensor 4. Always excluded from K.

Therefore, it is preferable to provide a contact sensor for detecting an obstacle close to the working member 23a so that the obstacle does not come into contact with the working member 23a, especially the working floor. A contact sensor is a sensor that can detect an obstacle such as a person or an object through contact with the person or the object from the outside. Contact sensors include, for example, tape switches and pressure-sensitive switches. The contact sensor constantly detects obstacles approaching the working member 23a. The detection area L of the contact-type sensor is preferably arranged so as to be able to detect obstacles approaching the working member 23a from the horizontal direction, from below, and from above. More preferably, it is arranged so that an obstacle approaching from the horizontal direction and/or below 23a can be detected.

Next, the operating procedure of the telescopic boom contact prevention device A using a contact sensor will be described with reference to FIG.

The contact sensor constantly detects contact with an obstacle while the telescopic boom contact prevention device A is in operation (S11). When an obstacle comes into contact with the contact sensor, the contact sensor transmits an obstacle detection signal to the effect that an obstacle has been detected to the telescopic boom operation suppressing means 6 (S12), and the telescopic boom operation suppressing means 6 causes the telescopic boom operation suppressing means 6 to extend and retract. The operation of the boom 2 is entirely stopped, or the operation (movement) in the direction approaching the location where the obstacle is detected is suppressed (S7). When the movement (movement) in the direction approaching the detected location of the obstacle is suppressed, the movement of the telescopic boom 2 in the direction away from the detected location of the obstacle is permitted. If necessary, the information may be output to the output module 85 by voice or display to alert the operator of the telescopic boom 2 and/or the worker on the working floor.

When the operation of the telescopic boom 2 is suppressed by the telescopic boom operation suppression means 6, the operator of the telescopic boom 2 checks the surroundings of the working member 23a, removes obstacles approaching the working member 23a, and then inputs A module 86 is used to send an obstruction removal signal to the telescopic boom motion restraint means. When the telescopic boom operation suppressing means 6 receives the obstacle removal signal, the telescopic boom operation suppressing means 6 cancels the suppression of the operation of the telescopic boom 2, returns to the operation before the obstacle was detected, and then proceeds to step 11. Returning, the contact prevention device of the telescopic boom resumes normal operation before detecting the obstacle.

In the above operation, the input module 86 is used to input the obstacle removal signal, thereby canceling the suppression of the operation of the telescopic boom. On the other hand, when the movement of the telescopic boom is restrained by the telescopic boom movement restraining means, the obstacle cannot be removed. That is, there is a situation in which the obstacle cannot be removed unless the telescopic boom 2 is moved in a direction to approach the obstacle.

When the above situation occurs, the input module 86 is used to input a suppression stop signal. When the telescopic boom operation suppression means receives the suppression stop signal, the telescopic boom operation suppression means is stopped (S13). All or part of the range sensor 2, the contact sensor, the boom length measuring device 3, the detection area setting means 5, and the speed comparison means 7 may be stopped by the suppression stop signal.

By stopping the telescopic boom operation suppression means, the suppression of the operation of the telescopic boom 2 by the telescopic boom operation suppression means is released, and the operation of the telescopic boom 2 in the direction of approaching the obstacle becomes possible. In this state, the operator of the telescopic boom 2 and/or the operator on the work floor raises, lowers and/or turns the telescopic boom while paying attention to obstacles, etc., and extends and retracts the telescopic boom as necessary. Move (traverse) the work vehicle as necessary to remove the obstacle.

After removing the obstacle, the input module 86 is used to input the obstacle removal signal. In response to the obstacle removal signal, the telescopic boom operation suppression means 6 resumes operation and returns to the state before the obstacle was detected (S14). After that, the process returns to step 2 or step 11, and the contact prevention device for the telescopic boom returns to normal operation before detecting the obstacle.

In addition, when all or part of the range sensor 2, contact sensor, boom length measuring device 3, detection area setting means 5 and speed comparison means 7 are stopped by the suppression stop signal, the obstacle In response to the removal signal, the range sensor 2, the contact sensor, the boom length measuring device 3, the detection area setting means 5, and the speed comparison means 7 all start their stopped operations, and return to the state before the obstacle was detected. do.

In the contact prevention device for the telescopic boom, the operation in response to the input of the suppression stop signal may be provided as required. 6 to 8 show the operation of the contact prevention device for the telescopic boom provided with the operation in response to the input of the suppression stop signal.

1 base machine 2 telescopic boom
21 base boom
22 intermediate boom
23 Top Boom
23a Working member 3 Boom length measuring device
31 Boom length measuring device transmitter
32 Boom length measuring device reflector 4 Ranging sensor 5 Detection area setting means 6 Telescopic boom operation suppression means 7 Speed comparing means A Contact prevention device D Boom length J Judgment range K Range sensor detection area L Contact sensor detection region

Claims (4)

a telescoping boom connected to the base machine for hoisting, swiveling and telescoping;
a boom length measuring device for measuring the boom length of the telescopic boom;
a range sensor that detects an obstacle existing within a detection area set along the telescopic boom;
detection area setting means for changing and setting the detection area of the range sensor based on the boom length measured by the boom length measuring device;
A contact prevention device for a telescopic boom, comprising a telescopic boom movement suppressing means for receiving an obstacle detection signal from the range sensor and suppressing movement of the telescopic boom. A work member is provided at the tip of the telescopic boom,
2. The telescopic boom contact prevention device according to claim 1, wherein the detection area setting means sets the detection area of the range sensor after excluding the working member at the tip of the telescopic boom. Speed comparing means for comparing the measured telescopic speed of the telescopic boom with a preset reference telescopic speed of the telescopic boom, and transmitting an overspeed signal to the telescopic boom operation suppression means when the measured telescopic speed exceeds the reference telescopic speed. with
3. The contact prevention of the telescopic boom according to claim 1, wherein the telescopic boom operation suppressing means receives the overspeed signal from the speed comparing means and suppresses the operation of the telescopic boom. Device. A work member is provided at the tip of the telescopic boom,
Having a contact sensor that detects an obstacle to the working member,
2. The telescopic boom contact prevention device according to claim 1, wherein the telescopic boom operation suppression means receives an obstacle detection signal from the contact sensor and suppresses the operation of the telescopic boom.

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