JP2005119789A - Safety device for high position working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety device for a high position working vehicle making operability sufficient by enabling the swing of a working base 6 even if actual load moment acting on an expansion/contraction boom 3 arrives at a limit at a high position, and making working range performance as wide as possible by setting limit load moment such that an increase in moment by swinging the working base 6 can be utilized for a moment increase direction by the expansion/contraction boom at a low position. <P>SOLUTION: Even if the actual load moment arrives at the limit load moment, the first limit load moment having a room so as to enable the swing driving of the working base in the moment increase direction and the second limit load moment having no room are selected by a selection means. If it arrives at the limit when the second limit load moment is selected by the selection means, the swing driving in the moment increase direction is prohibited and even if it arrives at the limit when the first limit load moment is selected by the selection means, the inhibition of the swing driving is not carried out. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a safety device for an aerial work vehicle.

  As shown in FIG. 6, this type of aerial work vehicle A has a swivel base 2 disposed on a vehicle 1, and a telescopic boom 3 is disposed on the swivel base 2 so that it can be extended and retracted. The telescopic boom 3 is configured such that the intermediate boom 3b and the tip boom 3c are sequentially inserted into the base boom 3a so as to be telescopically extendable, and telescopic drive means 8 (not shown) such as a telescopic hydraulic cylinder is appropriately disposed between the booms. The boom 3a to the intermediate boom 3b and the tip boom 3c can be extended or retracted sequentially or simultaneously. A hoisting hydraulic cylinder 4 is disposed between appropriate positions between the base boom 3a and the swivel base 2 so that the telescopic boom 3 can be driven to hoist.

  A vertical post 5 is swingably attached to the distal end of the telescopic boom 3 so that the vertical posture can always be maintained regardless of the up-and-down driving of the telescopic boom 3 and between the distal end of the telescopic boom 3 and the vertical post 5. An attitude maintaining device (not shown) is disposed in A work table 6 is attached to the vertical post 5 so as to be able to swing.

  Outriggers 9 including jacks that project and support the vehicle 1 are disposed in front, rear, left, and right positions of the vehicle 1.

  Such an aerial work vehicle A extends the outrigger 9 from the vehicle 1 to stably support the vehicle 1 from the ground by a jack, and extends and retracts, swings and drives the telescopic boom 3 and swings the work table 6 to swing. A work place 6 is positioned at a desired height position, and a worker who has boarded the work table 6 performs work at a height.

  By the way, in such an aerial work vehicle A, when the overturning direction moment acting on the telescopic boom 3 reaches a limit value, the overturning direction moment acting on the telescopic boom increases (the fall of the telescopic boom 3). A safety device is provided that regulates the drive and the extension drive of the telescopic boom 3. As a result, it is possible to prevent a fall of an aerial work vehicle and a breakage accident of the telescopic boom 3 in advance.

  Further, not only the tilting drive of the telescopic boom 3 and the extension driving of the telescopic boom 3, but also the swinging drive of the workbench 6 can move in a direction in which the overturning moment acting on the telescopic boom 3 increases. In a state where the operation of the boom 3 is restricted, it is determined whether the swing position of the work table 6 is on the left or right with respect to the longitudinal axis of the telescopic boom 3 in a plan view. Swinging is prohibited, and when it is on the right, swinging to the left is prohibited. That is, a technique for preventing an increase in the falling direction moment acting on the telescopic boom by restricting the swing drive to the front side of the telescopic boom 3 is known. (For example, refer to Patent Document 1).

On the other hand, even if the overturning direction moment acting on the telescopic boom 3 reaches the limit value, the workbench 6 can be swung, and even if the overturning moment acting on the boom is swung forward of the workbench 6, There is a known technique in which the swing drive is not restricted even if it is increased. In this way, after the workbench 6 is positioned at the target position by the telescopic boom 3, the operation of the workbench 6 can be swung and the workbench 6 can be easily positioned at a high place. A technique for providing a high-performance work vehicle with high performance is known (for example, see Patent Document 2).
No. 1-33590 JP 2002-265198 A

  By the way, the safety device for an aerial work vehicle that employs the above-described technique is such that even if the work table 6 is swung to the front side of the telescopic boom 3 in this state, the overturning direction moment acting on the telescopic boom 3 is in the neck. The work table 6 cannot be swung to the front side of the telescopic boom 3 because it increases by the amount of swing. In this case, in order to swing the workbench 6 to the front side of the telescopic boom 3, the telescopic boom 3 is lifted up or down once to reduce the overturning direction moment acting on the telescopic boom 3, and then the workbench 6 is telescopic. It was necessary to swing the head to the front side of the boom 3, and the operation was troublesome and the workability was poor.

  On the other hand, in the safety device for an aerial work vehicle employing the latter technique, when the workbench 6 is positioned on the rear side and the telescopic boom 3 is laid down, the overturning moment acting on the telescopic boom 3 is the limit value. Is reached, the overturning drive of the telescopic boom 3 is stopped. In this state, even if the work table 6 is swung to the front of the telescopic boom 3 and the moment value acting on the telescopic boom 3 is increased, the limit value is increased and the ratio of the limit value to the actual moment value is kept constant. Thus, the swinging drive of the work table 6 is not restricted. In other words, the limit value is slightly changed according to the swing position of the workbench 6, but the basic idea is that the workbench 6 is positioned rearward and the telescopic boom 3 is laid down. When the overturning direction moment acting on the telescopic boom 3 reaches the limit value, the work table 6 is swung forward so that the limit performance is reduced by the increase of the moment value acting on the telescopic boom 3. It is what.

  However, when working with the workbench 6 positioned at a relatively low position, the workbench 6 is moved to the front side in an aerial work vehicle that employs the safety device for an aerial work vehicle employing the latter technique. Since the limit performance is reduced in advance by the amount of moment that acts on the telescopic boom 3 by swinging the head, even if the work table 6 is to be positioned at a low position, the telescopic boom 3 is driven by falling or extending. When the actual load moment acting on the telescopic boom 3 reaches the limit load moment, the work range performance is so narrow that the workbench 6 cannot be positioned at a low position, which is unusable and poor in workability. It was.

  Thus, when working with the safety device for an aerial work vehicle that eliminates the disadvantages of both, that is, with the work table 6 positioned at a high position, even if the moment acting on the telescopic boom 3 reaches the limit. When the work table 6 can be swung to improve operability and the work table 6 is positioned at a low position, the limit value of the moment acting on the telescopic boom 3 is set to the swing of the work table 6. There has been a demand for a safety device for an aerial work vehicle that has a limit performance including a moment increase due to the above, and has a wide work range performance so that the work table can be positioned as low as possible. It is an object of the present invention to provide a safety device for an aerial work vehicle that satisfies such requirements.

  In order to achieve the above object, a safety device for an aerial work vehicle according to claim 1 of the present invention is configured such that an extendable boom is arranged on a vehicle so as to be extendable, undulating, and pivotable, and swings at the tip of the extendable boom. A safety device for an aerial work vehicle having a workbench disposed so as to be freely driven, a working state detecting unit for detecting a working state of the aerial work vehicle, a load detecting unit for detecting a load acting on the telescopic boom, and a work A moment calculation means for calculating the actual load moment and the limit load moment acting on the telescopic boom in response to signals from the state detection means and the load detection means, and comparing the actual load moment with the limit load moment, the actual load moment is limited. Comparing means for outputting a limit signal when the load moment is reached, and alarm means for receiving an alarm in response to the limit signal or regulation means for restricting the drive of the telescopic boom to the dangerous side Further, in the safety device for an aerial work platform, the moment calculating means has a first margin that allows a swing of the work table in the direction of increasing moment even if the actual load moment reaches the limit load moment. A first limit load moment calculating means for calculating a limit load moment; and a second limit which does not have a margin for enabling the table to be swung in the direction of increasing moment even when the actual load moment reaches the limit load moment. A second limit load moment calculating means for calculating the limit load moment, calculating two limit load moments, and selecting a limit load moment to be compared with the actual load moment by the comparing means among the two limit load moments; A limit signal from the comparison means when the selection means and the second limit load moment are selected by the selection means; When the first limit load moment is selected by the selection means, the head by the swing inhibition means even if a limit signal is received from the comparison means when the selection means selects the first limit load moment. There is provided a swing restriction release means for releasing the swing drive so as not to be prohibited.

  The safety device for an aerial work vehicle according to claim 2 of the present invention is such that the telescopic boom is disposed on the vehicle so as to be extendable, undulating, and pivotable, and an arm that is pivotably driven is disposed at the tip of the telescopic boom. This is a safety device for an aerial work vehicle in which a workbench is disposed at the tip of the vehicle so as to be able to swing and drive, and a work state detection means for detecting a work state of the work vehicle at a high position and a load acting on the telescopic boom are detected. The load detection means, the moment calculation means for calculating the actual load moment and the limit load moment acting on the telescopic boom in response to signals from the work state detection means and the load detection means, and the actual load moment and the limit load moment are compared. When the actual load moment reaches the limit load moment, the comparison means that outputs a limit signal and the alarm means that receives the limit signal and alarm or the drive of the telescopic boom to the dangerous side are regulated. In a safety device for an aerial work vehicle equipped with a restricting means, the moment calculating means can drive the arm in the direction of increasing moment and swing the work table even if the actual load moment reaches the limit load moment The first limit load moment calculating means for calculating the first limit load moment with a margin so as to reduce the rotation of the arm in the direction of increasing the moment even if the actual load moment reaches the limit load moment A second limit load moment calculating means for calculating a second limit load moment that does not have a margin for enabling swing drive, and calculates two limit load moments, A selection means for selecting a limit load moment to be compared with the actual load moment by the comparison means; When the second limit load moment is selected, the arm turning prohibiting means for prohibiting the turning drive of the arm in the moment increasing direction upon receipt of the limit signal from the comparison means, and the second limit load moment by the selecting means. When the limit signal from the comparison means is received during selection, the swing prohibiting means for prohibiting the swing drive of the work table in the direction of increasing moment is compared with when the first limit load moment is selected by the selection means. Arm turning restriction release means for releasing the arm turning drive prohibition by the arm turning prohibiting means even when receiving a limit signal from the means, and comparison means when the first limit load moment is selected by the selection means And a swing regulation canceling means for canceling the swing driving prohibition by the swing prohibiting means even when receiving a limit signal from the head. Is.

  According to claim 3 of the present invention, the safety device for an aerial work vehicle according to claim 1 or 2, wherein the selection means is configured to select the both limit load moments with a manual changeover switch. It is a feature.

  According to claim 4 of the present invention, the safety device for an aerial work vehicle according to claim 1 or 2, wherein the height of the work table is calculated by receiving a signal from the work state detecting means. Means for receiving a signal from the work table height calculating means, and selecting the first limit moment if the work table height is greater than or equal to a predetermined value, and selecting the first work moment if the work table height is less than or equal to the predetermined value. It is characterized in that the limit moment of 2 is selected.

  The safety device for an aerial work vehicle according to claim 5 of the present invention is the safety device for an aerial work vehicle according to claim 1 or 2, wherein the hoisting angle of the telescopic boom is detected in response to a signal from the work state detection means, The first limit moment is selected when the undulation angle of the telescopic boom is equal to or greater than a predetermined angle, and the second limit moment is selected when the undulation angle is equal to or less than the predetermined value. .

  According to a sixth aspect of the present invention, the safety device for an aerial work vehicle according to the first or second aspect is provided with an outrigger that has jacks that extend in front and rear, left and right positions of the vehicle to support the vehicle, and Means for detecting the extension width of the outrigger and the turning position of the telescopic boom, and the selection means receives a signal from the work state detection means, the extension width of the outrigger is equal to or less than a predetermined value, and the turning position of the extension boom is a lateral region of the vehicle The second limit moment is selected when the vehicle is positioned at the position, and the first limit moment is selected when the outrigger extension width is equal to or greater than a predetermined value or the turning position of the telescopic boom is positioned in the front-rear region of the vehicle. It is characterized by that.

  A safety device for an aerial work vehicle according to a first aspect of the present invention provides the first limit load moment of the limit load moment as a swing drive of the workbench in the direction of increasing the moment even if the actual load moment reaches the limit load moment. If the first limit load moment is selected by the selection means, even if the actual load moment acting on the telescopic boom reaches the limit load moment, it acts on the telescopic boom. The work table can be swung in a direction in which the load moment increases. The swinging drive of the workbench at this time is moved within the safe range, and the workbench is safely moved to the target position even when the safety device is activated and the operation of the telescopic boom is stopped. It is possible to improve the operability.

  In addition, select the second limit load moment of the limit load moment because it does not have a margin to allow the platform to swing in the direction of increasing moment even if the actual load moment reaches the limit load moment. If the second limit load moment is selected by means and the workbench is swung so that the workbench is positioned on the rear side of the telescopic boom, the moment increase due to the swinging drive of the workbench is changed to the moment increase due to the telescopic boom. It can be used, and the telescopic boom can be driven to fall down or extend as much as possible. When the actual load moment acting on the telescopic boom reaches the limit load moment, if the work table is swung in the direction in which the load moment acting on the telescopic boom increases, it is prohibited by the swing prohibiting means. Can be safe.

  For example, when the first limit load moment is selected by the selection means, the telescopic boom is laid down or extended while the work platform is positioned at a high position and the work platform is positioned on the rear side of the telescopic boom. Even if the overturning direction moment acting on the telescopic boom reaches the limit load moment and the overturning or extending drive of the telescopic boom stops, the work table can be swung to the front side of the telescopic boom. It is possible to provide a safety device for an aerial work vehicle with good operability.

  Also, work with the workbench at a low position (for example, when an operator enters the workbench from the ground, the telescopic boom should be laid down to the maximum, and if necessary, the telescopic boom should be extended to bring the workbench closer to the ground. If the second limit load moment is selected by the selection means, it is necessary to use the load state acting on the telescopic boom to the full limit load moment. Can be used for the moment increase by the telescopic boom by positioning the rear side of the telescopic boom and swinging the work table to the front side. Therefore, the moment increase due to the swing movement of the platform can be used for the moment increase due to the overturning or extension drive of the telescopic boom, the work platform can be positioned as low as possible, and the working range can be expanded. Can do.

  As described above, the safety device for an aerial work vehicle according to the first aspect of the present invention selects the first limit load moment and the second limit load moment according to the work purpose by the selection means, thereby improving operability. It is possible to provide a safety device for an aerial work vehicle that can improve the working performance range.

  The safety device for an aerial work vehicle according to a second aspect of the present invention provides the first limit load moment of the limit load moment, the arm turning drive and work in the direction of increasing the moment even when the actual load moment reaches the limit load moment. If the first limit load moment is selected by the selection means, even if the actual load moment acting on the telescopic boom reaches the limit load moment, The arm can be driven to swing and the work table can be swung in a direction in which the load moment acting on the telescopic boom increases. The pivoting drive of the arm and the swinging drive of the workbench at this time are moved within the safe range, and the workbench can be safely moved even when the safety device is activated and the telescopic boom is stopped. It can be moved to a target position, and operability can be improved.

  In addition, since the second limit load moment of the limit load moment is not provided with a margin to allow the head to be swung in the direction of increasing the moment even when the actual load moment reaches the limit load moment. If the second limit load moment is selected by the selection means and the arm and the workbench are swung and swung so as to be positioned on the rear side of the telescopic boom, the moment due to the swiveling of the arm and the swivel drive of the workbench The increased amount can be used as the moment increased by the telescopic boom, and the telescopic boom can be driven to fall down or extend as much as possible. When the actual load moment acting on the telescopic boom reaches the limit load moment, when the arm is swung in the direction in which the load moment acting on the telescopic boom is increased and the work table is swung, the arm pivot prohibiting means It is safe because it can be prohibited by swinging prohibition means.

  For example, when the first limit load moment is selected by the selection means, the telescopic boom is laid down with the work platform positioned at the high position and the arm and the work platform positioned on the rear side of the telescopic boom. Or, even when the telescopic boom is extended, the arm and the work platform are swung and swung to the front side of the telescopic boom even if the overturning direction moment acting on the telescopic boom reaches the limit value and the tilting motion or expansion motion of the telescopic boom stops. It can be driven. Therefore, when the work table is moved to a target position at a high place, the work table can be moved to the target position without the stop operation by the safety device by the swing drive and the swing drive of the arm. It can provide good aerial vehicle safety equipment.

  Also, work with the workbench in a low position (for example, when an operator enters the workbench from the ground, the telescopic boom should be laid down to the maximum and the telescopic boom should be extended if necessary. If it is necessary to use the load state acting on the telescopic boom to the full limit load moment, the second limit load moment is selected by the selection means, and the arm and workbench are selected. If the arm is positioned on the rear side of the telescopic boom, it is possible to use the performance of the moment increase by turning the arm forward and swinging the workbench forward to increase the moment by the telescopic boom. it can. Therefore, the moment increase due to the pivoting drive of the arm and the swinging drive of the work table can be used as the moment increase due to the overturning motion or extension motion of the telescopic boom, and the working range can be expanded.

  As described above, the safety device for an aerial work vehicle according to the second aspect of the present invention can improve operability by selecting the first limit load moment and the second limit load moment according to the work purpose by the selection means. It is possible to provide a safety device for an aerial work vehicle that can improve the working performance range.

  Since the safety device for an aerial work vehicle according to a third aspect of the present invention is configured such that the selection means is switched by a manual changeover switch according to the first or second aspect, the manual changeover is performed by an operator. The switch can be used to select the first limit load moment or the second limit load moment according to the work purpose, thereby improving the operability and widening the work performance range.

A safety device for an aerial work vehicle according to a fourth aspect of the present invention provides the safety device for an aerial work vehicle according to the first or second aspect,
The selection means receives the signal from the work table height calculation means, selects the first limit load moment when the work table height is higher than a predetermined level, and selects the first limit load moment when the work height is lower than the predetermined value. Since the two limit load moments are selected, both limit load moments can be automatically selected. Moreover, when working with the workbench positioned at a high position, even if the moment acting on the telescopic boom reaches the limit, the workbench can be swung to improve operability and the workbench is low. When working in the position, the limit load moment acting on the telescopic boom should be the limit load moment including the moment increase due to the swinging of the platform, and the platform should be positioned as low as possible by the telescopic boom. It is possible to provide a safety device for an aerial work vehicle that can widen the work range performance as much as possible.

The safety device for an aerial work vehicle according to a fifth aspect of the present invention includes:
The selection means receives the signal from the work state detection means, selects the first limit load moment when the undulation angle of the telescopic boom is greater than or equal to a predetermined angle, and selects the second limit moment when the undulation angle is equal to or less than the predetermined value. Since the limit load moment is selected, both limit load moments can be automatically selected. In addition, when working with the workbench positioned at a high position, even if the actual load moment acting on the telescopic boom reaches the limit load moment, the workbench can be swung to improve operability, When working with the platform at a low position, the limit load moment acting on the telescopic boom is set to the limit load moment including the moment increase due to the swinging of the platform, and the platform is lowered to the lowest position by the telescopic boom as much as possible. It is possible to provide a safety device for an aerial work vehicle in which the work range performance can be widened so that it can be positioned.

A safety device for an aerial work vehicle according to a sixth aspect of the present invention is the first aspect or the second aspect,
The selection means receives the signal from the work state detection means and selects the second limit load moment when the extension width of the outrigger is not more than a predetermined value and the turning position of the telescopic boom is located in the side region of the vehicle, The first limit load moment is selected when the outrigger extension width is equal to or greater than the predetermined value, or when the turning position of the telescopic boom is located in the front-rear region of the vehicle, so both limit load moments are automatically selected. be able to.

  That is, when the outrigger extension width is set to a predetermined value or less and the telescopic boom is positioned in the side region, the limit performance of the safety device is small and the work range performance of the workbench is narrow. Under such circumstances, the second limit load moment is selected, the limit load moment acting on the telescopic boom is set as the limit performance including the moment increase due to the swing of the work table, and the work range performance can be made as wide as possible.

  In addition, when the outrigger extension width is extended beyond a predetermined value, or when the telescopic boom is positioned in the front-rear region, the limit performance is relatively large, so the first limit load moment is selected and acts on the telescopic boom. Even when the moment reaches the limit load moment, the work table can be swung, and emphasis can be placed on improving operability rather than widening the work range performance.

  Hereinafter, an embodiment of the safety device for an aerial work vehicle according to the present invention will be described with reference to FIGS. 1 to 8 by taking the aerial work vehicle A described in the background art as an example.

  FIG. 1 is an explanatory diagram for explaining a first embodiment of the safety device for an aerial work vehicle according to the present invention, which will be described below with reference to FIG. In FIG. 1, reference numeral 10 denotes work state detection means for detecting the work state of an aerial work vehicle, which detects a undulation angle detector 11 that detects the undulation angle of the telescopic boom 3 and the length of the telescopic boom 3. A length detector 12 and a swing angle detector 13 for detecting the swing angle of the work table 6 are provided. Reference numeral 16 denotes a load detection means for detecting a load acting on the telescopic boom 3.

  Reference numeral 17 denotes comparison means for comparing the actual load moment with the limit load moment and outputting a limit signal when the actual load moment reaches the limit load moment. Reference numeral 18 denotes alarm means for alarming in response to a limit signal from the comparison means 17. Reference numeral 19 is a restricting means for receiving the limit signal from the comparison means 17 and restricting the drive of the telescopic boom 3 to the danger side. The expansion restricting means 19a for restricting the extension drive of the telescopic boom 3 and the fall of the telescopic boom 3 It is comprised with the lodging regulation means 19b which regulates a drive.

  Reference numeral 20 denotes moment calculating means for receiving signals from the work state detecting means 10 and the load detecting means 16 and calculating an actual load moment and a limit load moment acting on the telescopic boom 3. The moment calculating means 20 enables the actual load moment calculating means 21 for calculating the actual load moment acting on the telescopic boom 3 and the swinging drive of the workbench in the direction of increasing the moment even if the actual load moment reaches the limit load moment. The first limit load moment calculating means 22 for calculating the first limit load moment with a margin so as to allow the table to be swung in the moment increasing direction even if the actual load moment reaches the limit load moment And a second limit load moment calculating means 23 for calculating a second limit load moment that does not have a margin to calculate two kinds of limit load moments.

  30 is a selection means for selecting a limit load moment to be compared with the actual load moment by the comparison means 17 out of both limit load moments. The selection switch 31 is configured by a manual switch and outputs a selection signal. One of the limit load moments calculated by the first limit load moment calculation means 22 and the second limit load moment calculation means 23 is selected by the selection signal from the selection switch 31 arranged in the moment calculation means 20 and compared. The means 17 comprises switching means 24 for outputting the selected limit load moment.

  Reference numeral 40 denotes swinging prohibiting means for prohibiting swinging driving in the moment increasing direction when receiving a limit signal from the comparing means 17 when the selection means 30 selects the second limit load moment. The swing prohibiting means 40 includes a right swing restricting means 40a, a left swing restricting means 40b, and a moment increasing swing direction determining means 40c. The right swing control means 40a controls the clockwise swing drive of the work table 6 in plan view, and the left swing control means 40b controls the counterclockwise swing drive of the work table 6 in plan view. It is.

  The moment increasing swing direction discriminating means 40 c receives a signal from the swing angle detector 13 from the work state detecting means 10, and the moment that the swing drive from the current position of the work table 6 acts on the telescopic boom 3. It is determined whether or not the swing drive is in the increasing direction, and in the case of the swing driving in the moment increasing direction, the right swing control means that is the swing driving in the moment increasing direction is used as the limit signal from the comparison means 17. 40a or means for outputting to the left swing regulating means 40b.

  41 is normally closed, but when the selection switch 31 receives a selection signal for selecting the first limit load moment, the limit signal output from the comparison means 17 is sent to the right swing control means 40a and the left neck. This is a swing restriction canceling means that blocks the output from being prevented from being output to the swing restricting means 40b and cancels the restriction of the swing drive prohibition.

  The safety device for an aerial work vehicle according to the present invention according to the first embodiment configured as described above operates as follows. Now, it is assumed that the operator has selected the first limit load moment with the selection switch 31 of the selection means 30. When the workbench 6 is positioned at a high position and the workbench 6 is positioned on the rear side of the telescopic boom 3, the moment calculation means 20 is actually operated when the telescopic boom 3 is driven to fall down or extend. The comparison means 17 outputs a limit signal on the assumption that the actual load moment acting on the telescopic boom 3 calculated by the load moment calculation means 21 has reached the first limit load moment calculated by the first limit load moment 22. Suppose that

  An alarm is issued by the alarm means 18 based on a limit signal from the comparison means 17, and the limit signal is also output to the extension restricting means 19a and the fall restricting means 19b of the restricting means 19, so that the extension boom 3 is driven to extend or fall. Is regulated. Since the selection signal from the selection switch 31 is a signal for selecting the first limit load moment, the swing regulation release means 41 uses the limit swing signal output from the comparison means 17 as the right swing restriction means 40a and the left swing swing. It blocks so as not to output to the restricting means 40b, and acts to cancel the restriction of the swing drive prohibition.

  Therefore, although the inclining drive or the extension drive of the telescopic boom 3 is stopped, the work table 6 can be swung to the front side of the telescopic boom 3 (the swing drive in the moment increasing direction).

  That is, when the work table 6 is moved to a target position at a high place, the actual load moment acting on the telescopic boom 3 reaches the limit load moment, the safety device is activated, and the operation of the telescopic boom 3 is stopped. In addition, the work table 6 can be moved to a target position by swing driving, and a safety device for an aerial work vehicle with good operability can be provided.

  Next, work is performed with the workbench 6 positioned at a low position (for example, when an operator enters the workbench 6 from the ground, the telescopic boom 3 is laid down to the maximum, and the telescopic boom 3 is moved if necessary. The case where it is necessary to extend and position the workbench 6 close to the ground will be described. In this case, it is necessary to use the load state acting on the telescopic boom 3 to the full limit load moment, and the expansion of the telescopic boom 3 by driving the workbench 6 to the front side is driven to extend or fall down. It is necessary to use it for the moment increase due to.

  Therefore, the operator selects the second limit load moment by the selection switch 31 and places the work table 6 on the rear side of the telescopic boom 3. Then, the telescopic boom 3 is laid down and extended if necessary to place the workbench 6 near the ground. At this time, since the second limit load moment is selected by the selection switch 31, the moment increase due to the swinging drive amount of the work table is used as the moment increase due to the fall drive or extension drive of the telescopic boom. The work range can be expanded, and the work table 6 can be positioned as close to the ground as possible.

  Of course, when the actual load moment reaches the second limit load moment and the limit signal is output from the comparison means 17, the swing regulation release means 41 has selected the second limit load moment, so that it is cut off. The limit signal is output to each regulating means. That is, the right swing control means 40a or the left swing control means 40b is operated so as to control the swing drive in the moment increase direction by the moment increase swing direction control means 40c. Therefore, when the actual load moment has reached the second limit load moment, it is possible to prohibit the swinging of the work table 6 in the direction of increasing the moment.

  In this way, by selecting the first limit load moment and the second limit load moment according to the work purpose by the selection means 30, it is possible to improve the operability and work in a high place where the work performance range can be widened. A vehicle safety device can be provided.

  Next, in the first embodiment, the case where the safety device for an aerial work vehicle of the present invention is applied to the aerial work vehicle A shown in FIG. 6 has been described. However, the aerial work vehicle A ′ shown in FIG. A second embodiment in which the safety device for an aerial work vehicle according to the present invention is applied will be described below. The aerial work vehicle A ′ shown in FIG. 7 is different from the aerial work vehicle A shown in FIG. 6 in that an arm 8 is interposed between the vertical post 5 and the work table 6. That is, the arm 8 is attached to the vertical post 5 so as to be capable of turning, and the work table 6 is attached to the tip of the arm 8 so as to be able to swing. In describing the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  Hereinafter, a case where the safety device for an aerial work vehicle according to the present invention is applied to the aerial work vehicle A 'shown in FIG. 7 will be described with reference to FIG. In FIG. 2, reference numeral 10a denotes a work state detection means, which is additionally provided with an arm turning angle detector 14 for detecting the turning angle of the arm 8 from the work state detection means 10 shown and described in FIG. It is different in point.

  Reference numeral 20a denotes moment calculation means for receiving signals from the work state detection means 10a and the load detection means 16 and calculating an actual load moment and a limit load moment acting on the telescopic boom 3. The moment calculating means 20a includes an actual moment calculating means 21 for calculating an actual load moment acting on the telescopic boom 3, a turning drive of the arm 8 in the direction of increasing the moment even if the actual load moment reaches the limit load moment, and the work table 6 First limit load moment calculating means 22a for calculating a first limit load moment with a margin so as to enable swing drive, and an arm 8 in a moment increasing direction even if the actual load moment reaches the limit load moment And the second limit load moment calculating means 23a for calculating the second limit load moment that does not have a margin for enabling the swing drive of the work table 6 and the swing drive of the work table 6. Two kinds of limit load moments are provided. It is designed to calculate.

  30 is a selection means for selecting a limit load moment to be compared with the actual load moment by the comparison means 17 out of both limit load moments. The selection switch 31 is configured by a manual switch and outputs a selection signal. A comparison is made by selecting one of the limit load moments calculated by the first limit load moment calculation means 22a and the second limit load moment calculation means 23a by the selection signal from the selection switch 31 arranged in the moment calculation means 20. The means 17 comprises switching means 24 for outputting the selected limit load moment.

  Reference numeral 50 denotes arm turning prohibiting means for prohibiting arm turning driving in the moment increasing direction when receiving a limit signal from the comparing means 17 when the selection means 30 selects the second limit load moment. The arm turning prohibiting means 50 includes an arm right turning restricting means 50a, an arm left turning restricting means 50b, and a moment increasing arm turning direction determining means 50c. The arm right turn restricting means 50a restricts the clockwise turning drive of the arm 8 in a plan view, and the arm left turn restricting means 50b is a means for restricting the left turn drive of the arm 8 in a plan view. .

  The moment increasing arm turning direction discriminating means 50 c receives a signal from the arm turning angle detector 14 from the work state detecting means 10 a, and the moment that the arm turning drive from the current turning position of the arm 8 acts on the telescopic boom 3. It is determined whether or not the arm turning drive is in the increasing direction, and when the arm turning drive is in the moment increasing direction, the limit signal from the comparison means 17 is used as the arm turning right control that is the arm turning drive in the moment increasing direction. It is a means for outputting to the means 50a or the arm left turn restricting means 50b.

  51 is normally closed, but when the selection switch 31 receives a selection signal for selecting the first limit load moment 22a, the limit signal output from the comparison means 17 is sent to the arm right turn restricting means 50a. It is an arm turning restriction releasing means for blocking the output to the arm left turning restriction means 50b and releasing the restriction so as not to prohibit the arm turning drive.

  Reference numeral 40 'denotes a swing prohibiting means for prohibiting the swing drive in the moment increasing direction upon receiving a limit signal from the comparison means 17 when the selection means 30 selects the second limit load moment. The swing prohibiting means 40 'includes a right swing restricting means 40a, a left swing restricting means 40b, and a moment increasing swing direction determining means 40c'. The right swing control means 40a controls the clockwise swing drive of the work table 6 in plan view, and the left swing control means 40b controls the counterclockwise swing drive of the work table 6 in plan view. It is.

  The moment increasing swinging direction discriminating means 40c ′ receives signals from the swinging angle detector 13 and the arm turning angle detector 14 from the work state detecting means 10 and takes the turning position of the arm 8 into consideration for the current work. It is determined whether or not the swing drive from the position of the platform 6 is a swing drive in the moment increasing direction acting on the telescopic boom 3. Is output to the right swing restricting means 40a or the left swing restricting means 40b which is the swing drive in the moment increasing direction. The swing regulation release means 41 is normally closed, but when the selection switch 31 receives a selection signal for selecting the first limit load moment 22a, the limit signal output from the comparison means 17 is swung to the right. It is means for releasing the restriction so as not to output to the restricting means 40a and the left swing restricting means 40b and not to prohibit the swing drive.

  The safety device for an aerial work vehicle according to the present invention in the second embodiment configured as described above operates as follows. Now, it is assumed that the operator has selected the first limit load moment with the selection switch 31 of the selection means 30. When the workbench 6 is positioned at a high position and the arm 8 and the workbench 6 are positioned on the rear side of the telescopic boom 3, the telescopic boom 3 is tilted or extended while the moment calculating means 20 The comparison means 17 outputs a limit signal on the assumption that the actual load moment acting on the telescopic boom 3 calculated by the actual load moment calculation means 21 has reached the limit load moment calculated by the first limit load moment 22a. To do.

  An alarm is issued by the alarm means 18 based on a limit signal from the comparison means 17, and the limit signal is also output to the extension restricting means 19a and the fall restricting means 19b of the restricting means 19, so that the extension boom 3 is driven to extend or fall. Is regulated. Since the selection signal from the selection switch 31 is a signal for selecting the first limit load moment, the arm turning restriction release means 51 outputs the limit signal output from the comparison means 17 to the arm right turning restriction means 50a and the arm left turn. It blocks so as not to output to the rotation restricting means 50b, and acts so that the turning drive of the arm 8 is not restricted.

  Further, since the selection signal from the selection switch 31 is a signal for selecting the first limit load moment, the swing regulation release means 41 outputs the limit signal output from the comparison means 17 to the left swing regulation means 40a and the left. It blocks so as not to output to the swing regulating means 40b, and acts so as not to regulate the swing drive of the work table 6.

  Therefore, although the inclining drive or the extension drive of the telescopic boom 3 is stopped, the work table 6 can be swung to the front side of the telescopic boom 3 (the swing drive in the moment increasing direction). Further, the arm 8 can also be driven to turn the arm to the front side of the telescopic boom 3 (swing drive in the direction of increasing moment).

  That is, when the work table 6 is moved to a target position at a high place, even if the actual load moment acting on the telescopic boom 3 reaches the limit load moment and the safety device is activated, the swing drive and the arm swing drive are performed. The work table 6 can be moved to a target position, and a safety device for an aerial work vehicle with good operability can be provided.

  Next, work is performed with the workbench 6 positioned at a low position (for example, when an operator enters the workbench 6 from the ground, the telescopic boom 3 is laid down to the maximum and the telescopic boom 3 is extended if necessary. In this case, it is necessary to position the work table 6 close to the ground). In this case, it is necessary to use the state of the load moment acting on the telescopic boom 3 to the full limit load moment, and the moment caused by turning and swinging the arm 8 and the workbench 6 to the front side of the telescopic boom 3. It is necessary to use the performance of the increased portion for the increased moment of the telescopic boom 3 by the extension drive or the fall drive.

  Therefore, the operator selects the second limit load moment with the selection switch 31 and positions the arm 8 and the work table 6 on the rear side of the telescopic boom 3. Then, the telescopic boom 3 is driven to incline, and if necessary, it is driven to extend to position the workbench 6 close to the ground. At this time, since the second limit load moment is selected by the selection switch 31, the moment increase due to the swing drive of the arm 8 and the swing drive of the workbench 6 is reduced or driven to extend the extension boom 3. It can be used for the moment increase due to the drive, the work range can be expanded, and the work table 6 can be positioned as close to the ground as possible.

  Of course, when the actual load moment reaches the second limit load moment and the limit signal is output from the comparison means 17, the swing restriction release means 41 and the arm turning restriction release means 51 obtain the second limit load moment. Since it is selected, the limit signal is output to each regulating means without being cut off. That is, the right swing control means 40a or the left swing control means 40b is operated so as to control the swing drive in the moment increase direction by the moment increase swing direction control means 40c. Further, the arm right turn restricting means 50a or the arm left turn restricting means 50b is operated so as to restrict the arm turning drive in the moment increasing direction by the moment increasing arm turning direction restricting means 50c.

  Therefore, when the actual load moment has reached the second limit load moment, it is possible to prohibit the work table 6 from being swung in the direction of increasing the moment or the arm 8 from being driven to turn.

  As described above, also in the second embodiment, the selection means 30 selects the first limit load moment and the second limit load moment according to the work purpose, thereby improving the operability and widening the work performance range. It is possible to provide a safety device for an aerial work vehicle that can be taken.

  In the first embodiment and the second embodiment, the selection means 30 for selecting one of the two limit load moments is selected using the selection switch 31. However, the height of the work table 6 is not less than a predetermined value. You may make it select automatically depending on whether there exists. This case is shown in FIG. 3 as a third embodiment and will be described below.

  In the description of the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  In FIG. 3, 51 is a work table height calculation means, which receives the detection signals from the undulation angle detector 11 and the boom length detector 12 of the work state detection means 10 and determines the height of the work table 6. It is a means for calculating. Reference numeral 30a denotes a selection means for selecting a limit load moment to be compared with the actual load moment by the comparison means 17 out of two limit load moments. The selection means 30a includes a work table height determination means 52 and a switching means 24. doing.

  The work table height determining means 52 is a means for receiving a signal from the work table height calculating means 51 and determining whether or not the height of the work table 6 is a predetermined height or more. The first limit load moment calculated by the first limit load moment calculating means 22 is selected when the height of the work table 6 is equal to or higher than a predetermined height, and the height of the work table 6 is equal to or lower than the predetermined height. In this case, a selection signal is output to the switching means 24 so as to select the second limit load moment calculated by the second limit load moment calculation means 23. The switching means 24 is a limit load moment calculated from any one of the first limit load moment calculation means 22 and the second limit load moment calculation means 23 by a selection signal from the work table height determination means 52. And the limit load moment of the selected one is output to the comparison means 17.

  The safety device for an aerial work vehicle according to the present invention in the third embodiment configured as described above operates as follows. Assume that the work table 6 is positioned at a high position and the work table 6 is positioned on the rear side of the telescopic boom 3. At this time, since the workbench 6 is positioned at a high position, the height of the workbench 6 calculated by the workbench height calculation means 51 is a predetermined height or more, and the workbench height determination is performed. The means 52 outputs a selection signal to the switching means 24 so as to select the first limit load moment calculated by the first limit load moment calculation means 22. Then, the switching unit 24 causes the comparison unit 17 to output the first limit load moment calculated by the first limit load moment calculation unit 22 based on the selection signal.

  The actual load moment acting on the telescopic boom 3 calculated by the actual moment calculating means 21 of the moment calculating means 20 when the telescopic boom 3 is driven to incline or extend is calculated by the first limit load moment 22. It is assumed that the comparison means 17 outputs a limit signal on the assumption that the limit load moment of 1 is reached.

  An alarm is issued by the alarm means 18 based on a limit signal from the comparison means 17, and the limit signal is also output to the extension restricting means 19a and the fall restricting means 19b of the restricting means 19, so that the extension boom 3 is driven to extend or fall. Is regulated. Since the selection signal from the work table height discriminating means 52 is a signal for selecting the first limit load moment, the swing restriction release means 41 uses the limit signal output from the comparison means 17 as the right swing restriction means 40a. The left swing control means 40b is blocked from being output, and the swing drive is not restricted.

  Therefore, although the inclining drive or the extension drive of the telescopic boom 3 is stopped, the work table 6 can be swung to the front side of the telescopic boom 3 (the swing drive in the moment increasing direction).

  That is, when the work table 6 is moved to a target position at a high place, even if the actual load moment acting on the telescopic boom 3 reaches the limit load moment and the safety device is activated, the work table 6 is operated by swinging drive. It is possible to provide a safety device for an aerial work vehicle with good operability.

  Next, work is performed with the workbench 6 positioned at a low position (for example, when an operator enters the workbench 6 from the ground, the telescopic boom 3 is laid down to the maximum and the telescopic boom 3 is extended if necessary. In this case, it is necessary to position the work table 6 close to the ground). In this case, it is necessary to use the actual load moment acting on the telescopic boom 3 to the full limit load moment, and the telescopic boom 3 is driven to extend by the performance of the moment increase by swinging the work table 6 forward. Or it is necessary to use it for the moment increase by a fall drive.

  Here, since the workbench 6 is positioned at a low position, the height of the workbench 6 calculated by the workbench height calculation unit 51 is not more than a predetermined height, and the workbench height determination unit 52. Outputs a selection signal to the switching means 24 so as to select the second limit load moment calculated by the second limit load moment calculation means 23. Then, the switching unit 24 causes the comparison unit 17 to output the second limit load moment calculated by the second limit load moment calculation unit 23 based on the selection signal. Then, the work table 6 is positioned on the rear side of the telescopic boom 3 and the telescopic boom 3 is laid down or extended to position the work table 6 close to the ground.

  At this time, since the second limit load moment is selected by the selection switch 31, the moment increase due to the swing drive amount of the work table 6 is changed to the moment increase due to the fall drive or extension drive of the telescopic boom 3. It can be used, the work range can be expanded, and the work table 6 can be positioned as close to the ground as possible.

  Of course, when the actual load moment reaches the second limit load moment and the limit signal is output from the comparison means 17, the swing regulation release means 41 has selected the second limit load moment, so that it is cut off. The limit signal is output to each regulating means. That is, the right swing control means 40a or the left swing control means 40b is operated so as to control the swing drive in the moment increase direction by the moment increase swing direction control means 40c. Therefore, when the actual load moment has reached the second limit load moment, it is possible to prohibit the swinging of the work table 6 in the direction of increasing the moment.

  As described above, the selection means 30 automatically selects the first limit load moment and the second limit load moment depending on whether or not the height of the work table 6 is a predetermined height or more. It is possible to provide a safety device for an aerial work vehicle capable of improving the performance and widening the work performance range.

  In the third embodiment, the selection means 30a for selecting one of the two limit load moments is automatically selected depending on whether or not the height of the workbench 6 is greater than or equal to a predetermined level. You may make it select automatically depending on whether the undulation angle of 3 is a predetermined angle or more. Hereinafter, this case is shown in FIG. 4 as a fourth embodiment and will be described below.

  In describing the fourth embodiment, the same components as those in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  In FIG. 4, 30b is a selection means for selecting a limit load moment to be compared with the actual load moment by the comparison means 17 out of two limit load moments, and a undulation angle determination means 53, a switching means 24, It consists of. The undulation angle discriminating means 53 is a means for receiving a detection signal from the undulation angle detector 11 of the work state detection means 10 and discriminating whether the undulation angle of the telescopic boom 3 is a undulation angle greater than a predetermined value. The first limit load moment calculated by the first limit load moment calculating means 22 is selected when the undulation angle of the telescopic boom 3 is a predetermined or higher undulation angle, and the undulation angle of the telescopic boom 3 is below a predetermined level. When the height is higher, a selection signal is outputted to the switching means 24 so as to select the second limit load moment calculated by the second limit load moment calculation means 23.

  The switching unit 24 selects a limit load moment calculated from one of the first limit load moment calculation unit 22 and the second limit load moment calculation unit 23 based on a selection signal from the undulation angle determination unit 53. Then, the selected limit load moment is output to the comparison means 17.

  The safety device for an aerial work vehicle according to the present invention in the fourth embodiment configured as described above operates as follows. Assume that the work table 6 is positioned at a high position and the work table 6 is positioned on the rear side of the telescopic boom 3. At this time, since the work table 6 is positioned at a high position, the undulation angle of the telescopic boom 3 detected by the undulation angle detector 11 is an undulation angle greater than a predetermined value. A selection signal is output to the switching means 24 so as to select the first limit load moment calculated by the first limit load moment calculation means 22. Then, the switching unit 24 causes the comparison unit 17 to output the first limit load moment calculated by the first limit load moment calculation unit 22 based on the selection signal.

  Then, the actual load moment acting on the telescopic boom 3 calculated by the actual load moment calculating unit 21 of the moment calculating unit 20 by driving the telescopic boom 3 to incline or extend is calculated by the first limit load moment 22. It is assumed that the comparison means 17 outputs a limit signal on the assumption that the first limit load moment has been reached.

  An alarm is issued by the alarm means 18 based on a limit signal from the comparison means 17, and the limit signal is also output to the extension restricting means 19a and the fall restricting means 19b of the restricting means 19, so that the extension boom 3 is driven to extend or fall. Is regulated. Since the selection signal from the undulation angle determination unit 53 is a signal for selecting the first limit load moment, the swing regulation release unit 41 of the swing prohibiting unit 40 uses the limit signal output from the comparison unit 17 as the right neck. It blocks so as not to output to the swing restricting means 40a and the left swing restricting means 40b, and acts so as not to restrict the swing drive.

  Therefore, although the inclining drive or the extension drive of the telescopic boom 3 is stopped, the work table 6 can be swung to the front side of the telescopic boom 3 (the swing drive in the moment increasing direction).

  That is, when the work table 6 is moved to a target position at a high place, even if the actual load moment acting on the telescopic boom 3 reaches the limit load moment and the safety device is activated, the work table 6 is operated by swinging drive. It is possible to provide a safety device for an aerial work vehicle with good operability.

  Next, work is performed with the workbench 6 positioned at a low position (for example, when an operator enters the workbench 6 from the ground, the telescopic boom 3 is laid down to the maximum and the telescopic boom 3 is extended if necessary. In this case, it is necessary to position the work table 6 close to the ground). In this case, it is necessary to use the actual load moment acting on the telescopic boom 3 to the full limit load moment, and the telescopic boom 3 is driven to extend by the performance of the moment increase by swinging the work table 6 forward. Or it is necessary to use it for the moment increase by a fall drive.

  Here, since the workbench 6 is positioned at a low position, the undulation angle of the telescopic boom 3 detected by the undulation angle detector 11 is an undulation angle equal to or less than a predetermined value. A selection signal is output to the switching means 24 so as to select the second limit load moment calculated by the limit load moment calculating means 23. Then, the switching unit 24 causes the comparison unit 17 to output the second limit load moment calculated by the second limit load moment calculation unit 23 based on the selection signal. Then, the work table 6 is positioned on the rear side of the telescopic boom 3 and the telescopic boom 3 is laid down or extended to position the work table 6 close to the ground.

  At this time, since the second limit load moment is selected by the selection means 32b, the moment increase due to the swing drive amount of the workbench 6 is changed to the moment increase due to the fall drive or extension drive of the telescopic boom 3. It can be used, the work range can be expanded, and the work table 6 can be positioned as close to the ground as possible.

  Of course, when the actual load moment reaches the second limit load moment and the limit signal is output from the comparison means 17, the swing regulation release means 41 has selected the second limit load moment, so that it is cut off. The limit signal is output to each regulating means. That is, the right swing control means 40a or the left swing control means 40b is operated so as to control the swing drive in the moment increase direction by the moment increase swing direction control means 40c. Therefore, when the actual load moment has reached the second limit load moment, it is possible to prohibit the swinging of the work table 6 in the direction of increasing the moment.

  Thus, the selection means 30b automatically selects the first limit load moment and the second limit load moment depending on whether or not the undulation angle of the telescopic boom 3 is an undulation angle of a predetermined value or more. It is possible to provide a safety device for an aerial work vehicle capable of improving operability and widening the work performance range.

  In the fourth embodiment, the selection of the two limit load moments is automatically selected by the selection means 30b depending on whether or not the undulation angle of the telescopic boom 3 is equal to or greater than a predetermined undulation angle. You may make it select according to the working state of an aerial work vehicle determined by the width and the turning position of the telescopic boom.

  By the way, as shown in FIG. 8, when each outrigger 9 is fully extended, the maximum performance C is substantially the same for the entire circumference, but when each outrigger 9 is minimum extension, the maximum performance is obtained in the front-rear direction region. C, but the minimum performance D in the lateral region. Therefore, when the outrigger extension width is set to a predetermined value or less and the telescopic boom is positioned in the side region, the limit performance of the safety device is small and the work range performance of the workbench 6 is narrow. Further, when the outrigger 9 is extended beyond a predetermined width or the telescopic boom 3 is positioned in the front-rear region, the performance is relatively high. For this reason, when the purpose is to make the work range performance as wide as possible in the former case, and to focus on improving operability rather than widening the work range performance in the latter case This embodiment will be described below.

  This case will be described below with reference to FIG. 5 as a fifth embodiment. In FIG. 5, 10b is a work state detection means, and the work state detection means 10 for the aerial work vehicle detects a turning position of the telescopic boom 3 and a boom turning angle detector 15a. An outrigger extension width detector 15b for detecting the extension width of the outrigger 9 having a jack that supports the vehicle 1 by extending in the vehicle front-rear left-right position is additionally provided.

  Reference numeral 30 c denotes a selection unit, which includes an area determination unit 54, an outrigger extension width determination unit 55, a work state determination unit 56, and a switching unit 24. The region discriminating unit 54 is a unit that discriminates whether or not the turning position of the telescopic boom 3 is located in the front-rear region or the side region of the vehicle 1 in response to the detection signal from the boom turning angle detector 15a. The outrigger overhang width discriminating means 55 is a means for receiving a detection signal from the outrigger overhang width detector 15b and discriminating whether or not the outrigger overhang width is equal to or smaller than a predetermined value. The work state discriminating means 56 receives signals from the area discriminating means 54 and the outrigger overhang width discriminating means 55, and when the outrigger overhang width is not more than a predetermined value and the turning position of the telescopic boom 3 is located in the side area. Then, a selection signal for selecting the second limit load moment calculated by the second limit load moment calculation means 23 is output to the switching means 24, and the turning position of the telescopic boom 3 is determined when the outrigger extension width is greater than a predetermined value. When located in the front-rear region, a selection signal for selecting the first limit load moment calculated by the first limit load moment calculation means 22 is output to the switching means 24.

In addition, the selection signal output from the work state determination unit 56 is also sent to the swing regulation release unit 41. The swing restriction canceling means 41 receives the limit signal from the comparison means 17 when the selection signal for causing the switching means 24 to select the first limit load moment is received from the work state determination means 56. The output is blocked.
The swing regulation release means 41 receives the limit signal from the comparison means 17 when the selection signal for causing the switching means 24 to select the second limit load moment is received from the work state determination means 56. That is, when the first limit load moment is selected by the selection means 30c, even if the actual load moment reaches the first limit load moment, it acts on the telescopic boom 3. The swinging drive of the work table 6 in the direction in which the load moment to be increased is enabled. Further, when the second limit load moment is selected by the selection means 30c, when the actual load moment reaches the second limit load moment, the work table in the direction in which the load moment acting on the telescopic boom 3 increases. No. 6 swing drive is prohibited.

  The safety device for an aerial work vehicle according to the present invention in the fifth embodiment configured as described above operates as follows. Now, it is assumed that the work table 6 is swung to the rear side of the telescopic boom 3 in a state where the overhang width of the outrigger 9 is equal to or less than a predetermined value and the turning position of the telescopic boom 3 is located in the side region. Outrigger extension width determination means 55 receives the detection signal from the outrigger extension width detector 15 and determines that the extension width of the outrigger 9 is equal to or less than a predetermined value. The region discriminating means 54 receives the detection signal from the boom turning angle detector 14 and discriminates that the turning position of the telescopic boom 3 is located in the side region of the vehicle 1.

  The work state determination means 56 receives signals from the area determination means 54 and the outrigger extension width determination means 55, and the extension width of the outrigger 9 is equal to or less than a predetermined value and the turning position of the telescopic boom 3 is located in the side area. Then, a selection signal for selecting the second limit load moment calculated by the second limit moment calculation means 23 is output to the switching means 24. Accordingly, since the comparison means 17 compares the actual load moment calculated by the actual load moment calculation means 21 with the second limit load moment, the limit load moment acting on the telescopic boom 3 is determined as the neck of the work table 6. The limit load moment including the moment increase due to the swing is used, and the moment increase due to the swing drive amount of the work table 6 can be used as the moment increase due to the overturning drive or the extension drive of the telescopic boom 3. As a result, when the extension width of the outrigger 9 is set to a predetermined value or less and the telescopic boom 3 is positioned in the side region, the limit performance of the safety device is small and the work range performance of the workbench 6 is narrow as much as possible. Since the work range can be expanded, for example, the work table 6 can be positioned near the ground.

  Of course, when the actual load moment reaches the second limit load moment and the limit signal is output from the comparison means 17, the swing regulation release means 41 has selected the second limit load moment, so that it is cut off. The limit signal is output to each regulating means. That is, the right swing control means 40a or the left swing control means 40b is operated so as to control the swing drive in the moment increasing direction by the moment increasing swing direction restricting means 40c. Therefore, when the actual load moment has reached the second limit load moment, it is possible to prohibit the swinging of the work table 6 in the direction of increasing the moment.

  Next, it is assumed that the working table 6 is swung to the rear side of the telescopic boom 3 with the overhanging width of the outrigger 9 being a predetermined width or in a state where the telescopic boom 3 is positioned in the front and rear region. The outrigger overhang width discriminating means 55 receives the detection signal from the outrigger overhang width detector 15 and determines that the overhang width of the outrigger 9 is greater than or equal to a predetermined value. Alternatively, the region discriminating means 54 receives the detection signal from the boom turning angle detector 14 and discriminates that the turning position of the telescopic boom 3 is located in the front region or the rear region of the vehicle 1.

  The work state discriminating means 56 receives signals from the area discriminating means 54 and the outrigger overhang width discriminating means 55, and the switching is performed because the outrigger overhang width is greater than a predetermined value or the turning position of the telescopic boom 3 is located in the front and rear area. A selection signal for selecting the first limit load moment calculated by the first limit moment calculation means 22 is output to the means 24. Therefore, the comparison means 17 compares the actual load moment calculated by the actual load moment calculation means 21 with the first limit load moment.

  Here, when the telescopic boom 3 is driven to extend or fall down, the actual load moment calculated by the actual load moment calculating means 21 exceeds the first limit load moment, and a limit signal is output from the comparison means 17, and an alarm is issued. An alarm is output by the means 18 and the extension regulating means 19a and the fall regulating means 19b act to stop the extension drive and the fall drive of the telescopic boom 3.

  However, the swing restriction release means 41 receives a selection signal for causing the switching means 24 to select the first limit load moment from the work state determination means 56, and sends the limit signal from the comparison means 17 to each swing restriction means 40a, It acts to block output to 40b. Therefore, even if the actual load moment acting on the telescopic boom 3 reaches the first limit load moment and the telescopic boom 3 cannot be driven, the swinging drive of the work table 6 in the increasing direction of the moment acting on the telescopic boom 3 is performed. Can be possible. Therefore, when the workbench 6 is moved slightly to the target position, the workbench 6 is moved to the target position by swinging the workbench 6 without worrying about the moment acting on the telescopic boom 3 reaching the limit. Can do it.

  That is, in the state where the overhanging width of the outrigger is greater than or equal to a predetermined value or the telescopic boom is positioned in the front and rear region, the limit performance is smaller than when the outriggers are over the predetermined width and the telescopic boom is positioned in the side region. Since it is large, in this case, it is possible to place an emphasis on improving operability rather than widening the work range performance.

  In the third to fifth embodiments described above, the embodiment (only the swinging drive of the work table 6) is described in the case of being applied to the aerial work vehicle A illustrated in FIG. Thus, it goes without saying that the present invention may be similarly applied to the aerial work vehicle A ′ shown in FIG. 7 (the swing drive of the work table 6 and the swing drive of the arm 8).

  In the above embodiment, when applied to an aerial work vehicle A ′ having a work table 6 and an arm 8, both the swing drive of the work table 6 and the swing drive of the arm 8 are controlled. Of course, only one of them may be controlled.

  Furthermore, in the above embodiment, the safety device for an aerial work vehicle provided with both the alarm means 18 and the restricting means 19 has been described as an example. The present invention can also be applied to a safety device for an aerial work vehicle that is provided with only the warning means 18 without the restriction means 19.

It is explanatory drawing explaining 1st Embodiment of the safety device of an aerial work vehicle which concerns on this invention. (Example 1) It is explanatory drawing explaining 2nd Embodiment of the safety device of an aerial work vehicle which concerns on this invention. (Example 2) It is explanatory drawing explaining 3rd Embodiment of the safety device of an aerial work vehicle which concerns on this invention. Example 3 It is explanatory drawing explaining 4th Embodiment of the safety device of an aerial work vehicle which concerns on this invention. (Example 4) It is explanatory drawing explaining 5th Embodiment of the safety device of the aerial work vehicle which concerns on this invention. (Example 5) It is explanatory drawing explaining an aerial work vehicle. It is explanatory drawing explaining another aerial work vehicle. It is explanatory drawing explaining the performance of an aerial work vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 3 Telescopic boom 6 Worktable 8 Arm 10 Work state detection means 10a Work state detection means 10b Work state detection means 16 Load detection means 20 Moment calculation means 17 Comparison means 18 Alarm means 19 Regulation means 22 First limit load moment calculation Means 22a First limit load moment calculation means 23 Second limit load moment calculation means 23a Second limit load moment calculation means 30 Selection means 30a Selection means 30b Selection means 30c Selection means 40 Swing prohibition means 40 'Swing prohibition Means 50 Arm turning prohibiting means A Aerial work platform A 'Aerial work vehicle

Claims (6)

An aerial work vehicle safety device with a telescopic boom mounted on a vehicle so that it can be extended, retracted and swiveled, and a workbench placed at the tip of the telescopic boom so that it can be swung freely. Working state detecting means for detecting a state; load detecting means for detecting a load acting on the telescopic boom; and actual load moment and limit load moment acting on the telescopic boom in response to signals from the working state detecting means and the load detecting means; A moment calculating means for calculating the actual load moment and the limit load moment, a comparison means for outputting a limit signal when the actual load moment reaches the limit load moment, and an alarm means or expansion / contraction for alarming upon receiving the limit signal In a safety device for an aerial work vehicle provided with a restricting means for restricting the drive to the dangerous side of the boom,
The moment calculating means calculates a first limit load moment that has a margin so as to enable swinging of the workbench in the direction of increasing moment even if the actual load moment reaches the limit load moment. Load moment calculating means and a second limit for calculating a second limit load moment that does not have a margin to enable swinging of the work table in the direction of increasing the moment even when the actual load moment reaches the limit load moment Load moment calculating means for calculating two limit load moments, selecting a limit load moment to be compared with the actual load moment by the comparing means among the two limit load moments; When the limit load moment is selected, if the limit signal is received from the comparison means, the moment increases The swing prohibiting means for prohibiting the movement and the swing prohibiting means for canceling the swing drive by the swing prohibiting means even when the limit signal is received from the comparing means when the first limit load moment is selected by the selecting means. A safety device for an aerial work vehicle, comprising: Work in a high place where the telescopic boom is placed on the vehicle so that it can be extended, retracted and swiveled, an arm that can be swiveled is placed at the tip of the telescopic boom, and a workbench is placed at the tip of the arm so that it can be swung. A vehicle safety device, a working state detecting means for detecting a working state of an aerial work vehicle, a load detecting means for detecting a load acting on the telescopic boom, and signals from the working state detecting means and the load detecting means. A moment calculation means that calculates the actual load moment and the limit load moment acting on the receiving telescopic boom, and a comparison that outputs a limit signal when the actual load moment reaches the limit load moment by comparing the actual load moment with the limit load moment And a safety device for an aerial work vehicle having a warning means for receiving a limit signal and a warning means for restricting the driving of the telescopic boom to the dangerous side. Stomach,
The moment calculating means calculates a first limit load moment with a margin so as to enable the arm turning drive and the workbench swing drive in the direction of increasing the moment even when the actual load moment reaches the limit load moment. And a second limit load moment calculating means that does not have a margin to enable the arm turning drive and the work table swing drive in the direction of increasing the moment even when the actual load moment reaches the limit load moment. A second limit load moment calculating means for calculating a limit load moment, calculating two limit load moments, and selecting a limit load moment to be compared with the actual load moment by the comparison means among the two limit load moments And selecting means for comparing when the second limit load moment is selected by the selecting means If the limit signal from the comparison means is received when the second limit load moment is selected by the selection means and the arm turning prohibiting means for prohibiting the turning driving of the arm in the direction of increasing the moment when the limit signal is received. The swinging prohibiting means for prohibiting the swing drive of the work table in the increasing direction, and the arm turning prohibiting means even when receiving the limit signal from the comparison means when the selection means selects the first limit load moment. Arm swing restriction canceling means for canceling the prohibition of arm swing drive, and swinging by the swing prohibiting means even when a limit signal is received from the comparison means when the first limit load moment is selected by the selection means A safety device for an aerial work vehicle, comprising: a swing regulation canceling means for canceling the prohibition of driving. 3. The safety device for an aerial work vehicle according to claim 1 or 2, wherein the selecting means is configured to select the both limit load moments by a manual changeover switch. 3. The work table height calculating means for calculating the height of a work table in response to a signal from the work state detecting means according to claim 1 or 2, wherein the selecting means is provided by a work table height calculating means. The first limit load moment is selected when the platform height is greater than or equal to a predetermined level, and the second limit load moment is selected when the platform height is less than or equal to the predetermined range. Safety equipment for aerial work platforms. 3. The first or second aspect of the invention according to claim 1 or 2, wherein when the signal from the work state detecting means is received, the undulation angle of the telescopic boom is detected, and the selection means has a first undulation angle greater than or equal to a predetermined undulation angle. A safety device for an aerial work vehicle, characterized in that a second limit load moment is selected when a limit load moment of 2 is selected and a undulation angle equal to or less than a predetermined angle is selected. In Claim 1 or Claim 2, the outrigger which has a jack which extends in the front-and-rear right-and-left position of a vehicle and supports a vehicle is arranged. The selection means receives the signal from the work state detection means and selects the second limit load moment when the outrigger extension width is equal to or less than a predetermined value and the turning position of the telescopic boom is located in the lateral region of the vehicle. A safety device for an aerial work vehicle characterized in that the first limit load moment is selected when the overhang width of the outrigger is not less than a predetermined value or the turning position of the telescopic boom is located in the front-rear region of the vehicle. .

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